Rekeyable master and user lock system with high security features.

This invention relates generally to cyclinder locks, and more specifically to a rekeyable lock method and apparatus that wherein a master key lock system can be rekeyed externally for different master level keys as well as for different user level keys.

Lock devices generally known as tumbler pin cylinder locks have been widely used for many years to secure door locks, padlocks, and many other types of locks. More recently, variations and improvements have been developed for rekeying such tumbler pin cylinder locks without having to disassemble the locks. The following _U.S. patents are examples of such externally rekeyable or changeable combination locks: U.S. Patent No. 3,078,705, issueed to D. Morrison, Jr.; U.S. Patent No. 3,070,987, issued to A.R. Baker, et al; U.S. Patent No. 3,125,878, issued to L. Gutman; U.S. Patent No. 3,563,071, issued to L.N. Barger; U.S. Patent No. 3,175,378, issued to F.J. Russell; U.S. Patent No. 3,073 146, issued to _G._P. Patriquin; and U.S. Patent No. 1,650,568, issued to _N._B. Hurd.

The Morrison patent, U.S. Patent No. 3,078,705, as well as the Republic of Germany Patent No. DE 3040646AL, issued to F. Muus on June 19, 1981, disclose a method and apparatus for rekeying tumbler pin cylinder locks by utilizing a short temporary pin or wafer between the driver and tumbler pins to create a different shear line that is alignable by the appropriate key bitting with the shear line between the lock cylinder and housing to allow the cylinder to be rotated by the key. When the lock is to be rekyed, a special disabling key is inserted into the keyway in the cylinder. This special disabling key and bitting thereon cut to push the wafer into the top chamber and a notch in its spine opposite the bitting to receive and capture the wafer when the key and cylinder are rotated 180 degrees. The captured wafer is then extracted and expelled from the lock when the special key is pulled out of the keyway.

While the Morrison and Muus devices are effective to rekey the lock, there are several problems with its use. One of the most signficant of these problems is that once the temporary pin or wafer is removed from the lock as taught by Morrison and Muus, one dare not reinsert the special disablingkey into the keyway and turn the cylinder with it. If this is done, the top or driver pin in the top chamber will fall into the notch in the spine of the special disabling key. In that position, the cylinder cannot be turned again, and the special disabling key cannot be withdrawn. It remains stuck in that position, and the lock is rendered useless. It is, for practical purposes, ruined.

The only way to prevent this situation from occurring is to either destroy the special disabling key after its first use or take other elaborate precautionary measures to insure that it is not again mistakenly used in the lock. Unfortunately, many lock users do not take these precautions.

My improved rekeyable lock invention, on which my U.S. Patent No. 4,412,437 was issued on November 3, 1983, was an attempt to solve this problem. It utilizes a short temporary pin or wafer that is smaller in diameter than the main driver and tumbler pins in the lock. It also utilizes a notch in the spine of the special disabling or change key that is sized to capture the smaller diameter wafer, but which in combination with the keyway is too small to receive the larger diameter driver or top pin. Thus, the larger driver pin is physically prevented from entering the notch in the disabling or change, key, even if that same disabling or change key is inserted into the keyway and turned after the wafer has been removed. While this improvement has eliminated the problem of irretrievably sticking the special disabling or change key in the lock, it does still have some unique problems of its own. The most significant of suchproblems is that the smaller diameter wafers have a tendency to flip over on their sides in the chamber, thus affecting the proper functioning of the lock.

The Morrison and-Muus patents also are used only as construction keys wherein one key change is taught. My improved rekeyable lock invention in my issued U.S. Patent No. 4,412,437 expands such usage to include several levels of key changes for users. However, all such prior art patents have been limited to apparatus in which either user levels or master levels could be changed but not both.

More specifically, a master key lock system is one in which a master key can be used to unlock all of a whole group of locks, each of which requires a different user key. Such systems are often used by building owners to give the owner, maintenance, or security people ready access to many premises in the building, while the tenant's or user's key can only provide access to a specific one of such premises. The purpose of the master key is to reduce the number of keys the owner, maintenance, or security people must carry or maintain. However, while such master key systems increase efficiency, the existence of the master keys also reduce security. If a master key is lost, stolen, or secretly copied, every tenant's or user's premises is more susceptible to unauthorized entry. If security is to be maintained, the owner must change all of the locks in the group for which the master key is operable. Such changing of many locks was a costly procedure prior to this invention, so there was often the temptation to forego this expense and hope for the best. Unfortunately, from this approach, losses could occur, and the owner could incur substantial legal liabilities. Therefore, it has been found desirable to be able to provide high security rekeyable locks in which both user level keying combination and master level keying combinations can be changed independently of each other and without affecting the operation or keying of the other.

Another fact that exacerbates the security problems with master key systems, as well as with rekeyable locks, is that these master and rekeying functions operate off a plurality of different shear planes between the driver and service pins of the lock. Unfortunately, the more shear planes, the easier it is to "pick" the lock and gain unauthorized entry. A number of improvements over the prior art are required to provide a lock system that is rekeyable for both the user and the master levels and is easy enough to use for ordinary individuals, yet reliable and secure enough to provide the protection for which locks are used.

Another limitation of the prior art rekeyable locks, such as the Morrison and Muus patents, as well as my prior art apparatus in my U.S. Patent No. 4,412,437, is that the cylinders and keys in those locks have to be rotated 180 degrees in order to align the removal notch in the key spine with the temporary pin or wafer in order to capture and remove the wafer from the lock. Unfortunately, the latch mechanisms to which many of these locks are connected in doors, padlocks, and other devices, do not accomodate or allow 180 degree rotation of the lock cylinder. Such installations cannot utilize the rekeyable locks shown in the Morrison or Muus patents or in that rekeyable lock shown in my U.S. Patent No. 4,412,437. Several other prior art patents, such as those issued to Patriquin, Russell, Baer, Barger, and Hurd, dislcose externally rekeyable locks that do not require 180 degree rotation of the cylinder, but they only show one available rekeying operation. Therefore, there is still a need for a rekayble lock that can be rekeyed a multiple of times externally for use with multiple user level and/or master level rekeying.

In summary, the prior art rekeyable locks do not provide multiple user level and master level rekeyable options. Further, they do not provide fool-proof mechanisms for users or sufficient security from being picked or opened by unauthorized persons, especially in the multiple level rekeyable configurations.

To further achieve the foregoing and other objects in accordance with the purpose of this invention as well as to facilitate practice of this invention, this invention also includes methods of assembling and using the lock apparatus summerized above for rekeying operations and increasing security of such lock.

Accordingly, it is a general object of this invention to provide a multiple user level and/or master level externally rekeyable lock.

It is also a general object of this invention to provide a more secure lock apparatus, especially where such lock apparatus is configured as a multiple level rekeyable lock.

A more specific object of this invention is to provide a tumbler pin cylinder lock that is rekeyable externally to change multiple user levels as well as multiple master levels.

A further specific object of this invention is to provide such a lock wherein the user level changes are independent of, and do not affect, the master key configurations and vice versa.

Another specific object of this invention is to provide an externally rekeyable tumbler pin cylinder lock in which full size removeable wafers are used in combination with a special key adapted for removing the wafer for such rekeying, and wherein reinsertion and reuse of the special key does not result in sticking the key in the lock and rendering the lock unusable.

An additional object of this invention is to provide a multiple level externally rekeyable lock that does not require 180 degree cylinder rotation for rekeying.

still another object of this invention is to provide increased security against picking or unauthorized opening of locks, especially multiple level rekeyable locks according to this invention.

A further specific object of this invention is to provide such increased security by apparatus that inhibits or eliminates detection of shear plane alignment for the individual tumbler pins in a tumbler pin cylinder lock.

Additional objects, advantages, and novel features of the invention are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following specification or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumenta- lities and in combinations pointed out in the appended claims.

To achieve the foregoing and other objects in accordance with the purpose of the present invention as well as to facilitate the practice of this invention, the apparatus of this invention may comprise a tumbler pin lock that has a plurality of level change pin wafers in one pin chamber for a number of user level keying options and a plurality of level change pin wafers in another pin chamber for a number of master level keying options. In order to separate the master key system from the user key system, the user keys generally work off the shear line at the bottom of the driver pin and over the- user level change wafers in the chamber containing the user level change wafers and off the shear line at the top of the service pin and under the master level change wafers in the chamber containing the master level change wafers. The master key, on the other hand, works off the shear line at the top of the service pin and under the user level change wafers in the chamber containing the user level change wafers and off the bottom of the driver pin and over the master level change wafers in the chamber containing the master level change wafers. An additional permanent master pin wafer is also provided in another chamber of the lock to keep the master and user keys distinct after all the level change wafers have been removed. The apparatus also has bevelled edges along the keyway in the cylinder for camming the driver pins out of the ejection notches in the spines of the level change keys.

For additional security, the level change wafers are provided in a unitary rigid stack. The wafers in the stack are secured, by an adhesive or by a rigid core of frangible material through the centers of the wafers or by a rigid sleeve of frangible material around the peripheral surfaces of the wafers. The solid frangible material is preferably graphite to lubricate the lock.

High security embodiments of the invention include interlocking cotters and slots on the bottoms of driver pins and tops of service pins, respectively, that have to be oriented transverse to the longitudinal axis of the cylinder in order for the cylinder to rotate. The cotters can have rounded cam surfaces on the bottom, .or they can be squared. If they are squared, adjacent slots in the cylinder are provided to cam the cotters out of the pin chambers in the cylinder so the cylinder can rotate to open the lock.

For locks that cannot accommodate 180⁰ rotation of the cylinder, this invention also includes alternate embodiments for rekeyable multiple level user and master levels according to the principles of this invention. In one such embodiment, ejection holes through the lock body are provided adjacent the pin chambers through which level change wafers are ejected by rotation of the cylinder. Recessed troughs in the cylinder, either connected to the pin chamber therein or angularly spaced apart from the pin chamber, provide positive engagement to eject the level change wafers through the ejection holes and out of the lock. A blocking wafer,_larger than the ejection hole is also provided to retain master level change wafers in the lock during user level key operations. Another embodiment of this invention has change wafer capture holes in the cylinder deep enough to capture and retain a mutliple of level change wafers. The capture holes and level change wafers are smaller in diameter than the driver pins, and blocking wafers larger in diameter than the capture holes are provided to block level change wafers out of the captive holes when level changes are not desired.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in, and form a part hereof, the specifications, illustrate the preferred embodiments of the present invention, and together with the description, serve to explain the principles of the invention. In the drawings:

<ul id="ul0001" list-style="none"><li>Figure 1 is a side elvation view of a key that is typical of the key utilized in the present invention and illustrating the conventional terminology for bits and cuts as used in the description of this invention;</li><li>Figure 2 is an isometric view showing the cylinder, tumbler pin, and key components of the multiple level user and master key system of the present invention;</li><li>Figure 3 is an isometric view of the multiple level user and master key system of the present invention in a high security lock embodiment;</li><li>Figure 4 is a cross-sectional view of the multiple level user and master key system of the present invention with the first level user key inserted therein;</li><li>Figure 5 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 5-5 of Figure 4;</li><li>Figure 6 is a cross-sectional view of the multiple level user and master key system of the present invention with the first level user key positioned therein and rotated 1800;</li><li>Figure 7 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 7-7 of Figure 6;</li><li>Figure 8 is a cross-sectional view of the multiple level user and master key system of the present invention with the first level master key positioned therein;</li><li>Figure 9 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 9-9 of Figure 8;</li><li>Figure 10 is a cross-sectional view of the multiple level user and master key system of the present invention ; with the first level master key positioned therein and rotated 180⁰;</li><li>Figure 11 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 11-11 of Figure 10;</li><li>Figure 12 is a cross-sectional view of the multiple level user and master key system of the present invention with the second level key positioned therein;</li><li>Figure 13 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 13-13 of Figure 12;</li><li>Figure 14 is a cross-sectional view of the multiple level user and master key system of the present invention with the second level user key positioned therein and rotated 180_0;</li><li>Figure 15 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 15-15 of Figure 14;</li><li>Figure 16 is a cross-sectional view of the multiple level user and master key system of the present invention with the second level user key positioned therein and illustrating the removal of the first level wafer;</li><li>Figure 17 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 17-17 of Figure 16;</li><li>Figure 18 is a cross-sectional view of the user and master key system of the present invention with the first level user key reinserted therein after the first level wafer has been removed;</li><li>Figure 19 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 19-19 of Figure 18:</li><li>Figure 20 is a cross-sectional view of the multiple level user and master key system of the present invention with the first level master key inserted therein to illustrate the operation thereof after the first level wafer has been removed;</li><li>Figure 21 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 21-21 of Figure 20;</li><li>Figure 22 is a cross-sectional view of the multiple level user and master key system of the present invention taken with the second level user key reinserted therein and rotated 180⁰ after the first level user wafer has been removed;</li><li>Figure 23 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 23-23 of Figure 22;</li><li>Figure 24 is a cross-sectional view of the multiple level user and master key system of the present invention similar to that illustrated in Figure 23, but with the cylinder rotated several degrees to illustrate the upward biasing of the keyway sides on the driver pin to move the driver pin out of the keyway;</li><li>Figure 25 is a cross-sectional view of the multiple level user and master key system of the present invention similar to Figures 23 and 24 but with the cylinder rotated an additional several degrees illustrating the successful removal of the driver pin from the keyway;</li><li>Figure 26 is a cross-sectional view of the multiple level user and master key system of the present invention similar to Figures 23, 24, and 25, but with the cylinder successfully rotated -to the position where it can be removed;</li><li>Figure 27 is a cross-sectional view of the multiple level user and master key system with the second level master key positioned therein;</li><li>Figure 28 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 28-28 of Figure 27;</li><li>Figure 29 is a cross-sectional view of the multiple level user and master key system with the second level master key positioned therein and rotated 90⁰;</li><li>Figure 30 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 30-30 of Figure 29;</li><li>Figure 31 is a cross-sectional view of the multiple level user and master key system of the present invention with the second level master key positioned therein to remove the first level master wafer therefrom;</li><li>Figure 32 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 32-32 of Figure 31;</li><li>Figure 33 is a cross-sectional view of the multiple level user and master key system of the present invention showing the first level master key reinserted therein after the first level master wafer has been removed;</li><li>Figure 34 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 34-34 of Figure 33;</li><li>Figure 35 is a cross-sectional view of the multiple level user and master key system of the present invention with the second level user key reinserted therein and shown operable after the first level master wafer has been removed therefrom;</li><li>Figure 36 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 36-36 of Figure 35;</li><li>Figure 37 is a side elevation view of the third level user key;</li><li>Figure 38 is a side elevation view of the fourth level user key;</li><li>Figure 39 is a cross-sectional view of the multiple level user and master key system of the present invention with the fifth level user key positioned therein;</li><li>Figure 40 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 40-40 of Figure 39;</li><li>Figure 41 is a cross-sectional view of the multiple level user and master key system of the present invention with the third level master key positioned therein;</li><li>Figure 42 is a cross-sectional view of the multiple level user and master key system of the present invention taken along line 42-42 of Figure 41;</li><li>Figure 43 is an isometric view of a stack of mulitple level removable wafers for use in the multiple level user and master key system of the present invention with the wafers in the stack adhered together in a solid column;</li><li>Figure 44 is a cross-sectional view in elevation of the adhered multiple level wafer stack illustrated in Figure 43;</li><li>Figure 45 is an alternate embodiment of the multiple level wafer stack for use in the present invention with a solid, frangible graphite core therethrough;</li><li>Figure 46 is a cross-sectional view in elevation of the multiple level wafer stack illustrated in Figure 45;</li><li>Figure 47 is an isometric view of another embodiment of a multiple level wafer stack for use in the multiple level user and master key system of the present invention wherein the wafer stack is positioned in a solid, frangible graphite sleeve;</li><li>Figure 48 is a cross-sectional view in elevation of the multiple level wafer stack shown in Figure 47;</li><li>Figure 49 is an isometric view of an alternate embodiment high security multiple level user and master key system according to the present invention;</li><li>Figure 50 is an isometric view of the high security embodiment multiple level user and master.key system of the present invention with an appropriately configured and cut key inserted therein for opening the lock;</li><li>Figure 51 is a side elevation view of an appropriately cut and configured key as shown in Figure 50;</li><li>Figure 52 is a top plan view of the key shown in Figure 51;</li><li>Figure 53 is a side elevation view of a typical service pin utilized in the high security multiple user and master key system of Figures 49 and 50;</li><li>Figure 54 is a front elevation view of the service pin shown in Figure 53;</li><li>Figure 55 is a cross-sectional view in side elevation of the high security embodiment multiple level user and master key system of Figures 49 and 50;</li><li>Figure 56 is a cross-sectional view of the high security embodiment multiple level user and master key system of the present invention taken along line 56-56 in Figure 55;</li><li>Figure 57 is a cross-sectional view similar to that shown in Figure 56, but with the cylinder rotated several degrees to illustrate the upward camming on the driver pin by the cylinder;</li><li>Figure 58 is a cross-sectional view of the high security multiple level user and master key system similar to Figures 56 and 57, but with the cylinder rotated an additional several degrees to illustrate the operational movement thereof with the driver pin cammed out of the cylinder pin hole;</li><li>Figure 59 is an isometric view of the high security embodiment of this invention shown in Figures 49 and 50, but utilized only for the high security function without the multiple level user and master key system;</li><li>Figure 60 is an isometric view of the embodiment of the high security lock system shown in Figure 59 with an appropriately cut and bitted key positioned therein to open the lock;</li><li>Figure 61 is a side elevation view of an appropriately cut and configured key to open the lock as shown in Figure 60;</li><li>Figure 62 is a top plan view of the key illustrated in Figure 61;</li><li>Figure 63 is an isometric view of the essential components of another embodiment of the high security lock system similar to that shown in Figure 59,. but with a different driver pin camming structure;</li><li>Figure 64 is an isometric view of the alternate embodiment lock shown in Figure 63, but with a key inserted in the cylinder to unscramble the orientation of the high security pins therein;</li><li>Figure 65 is a cross-sectional view of the fourth pin position of the lock shown in Figure 64 with the key inserted therein to position the pins for opening the lock;</li><li>Figure 66 is a cross-sectional view similar to Figure 65, but with the cylinder rotated several degrees to illustrate the upward camming of the cylinder on the driver pin;</li><li>Figure 67 is a cross-sectional view similar to Figures 65 and 66, but with the cylinder rotated an additional amount to show the cotter on the driver pin cammed completely out of the slot so that the lock can be successfully opened by the key therein;</li><li>Figure 68 is an isometric view of another embodiment of the multiple level user and master key system of the present invention which is suitable for uses in locks wherein rotation of the cylinder is limited by the latch mechanism to less than 180⁰;</li><li>Figure 69 is a side elevation view of a typical padlock with a portion of the side thereof cut away to illustrate the position of the lock embodiment shown in Figure 63 therein;</li><li>Figure 70 is a bottom plan view of the padlock shown in Figure 69 with the key removed and with the retainer mechanism removed to show the open chamber therein wherein removed level wafers can be discarded by the multiple level user and master key system shown in Figure 68;</li><li>Figure 71 is a side elevation view of the multiple level user and master key system shown in Figure 68;</li><li>Figure 72 is a cross-sectional view of the multiple level user and master key system of Figures 68 and 71 taken along line 72-72 of Figure 71;</li><li>Figure 73 is a cross-sectional view similar to Ficure ₇2, but with the cylinder of the lock rotated several degrees to illustrate the operational ejection of a level wafer therefrom;</li><li>Figure 74 is a cross-sectional view of the lock of Figures 68 and 71 similar to that shown in Figures 72 and 73, but with the cylinder rotated an additional several degrees to show the successful ejection of the level wafer therefrom according to this invention;</li><li>Figure 75 is a cross-sectional view of the multiple level user and master key system of Figures 68 and 71 taken along line 75-75 of Figure 71;</li><li>Figure 76 is a cross-sectional view similar to Figure 75, but illustrating a different master key therein for changing the keying of the lock for the master key part of the system;</li><li>Figure 77 is a cross-sectional view similar to that shown in Figure 74, but with the cylinder in a position corresponding to that shown in Figure 76 to illustrate the maintenance of the present user keying combination while changing the master key keying combination;</li><li>Figure 78 is an isometric view of a modified cylinder of the multiple level user and master key system embodiment shown in Figure 68;</li><li>Figure 79 is a cross-sectional view of the number 6 pin and chamber section of the multiple level user and master key system lock embodiment shown in Figure 78 with a first level wafer therein positioned for removal;</li><li>Figure 80 is a cross-sectional view similar to Figure 79, but with the cylinder rotated several degrees to illustrate the positive engagement of the level wafer to be removed therefrom;</li><li>Figure 81 is a cross-sectional view similar to that shown in Figures 79 and 80, but with the cylinder rotated several degrees in reverse to illustrate the operational removal of level wafer therefrom;</li><li>Figure 82 is a cross-sectional view similar to-Figure 79, 80, and 81, but with the cylinder rotated an additional several degrees to illustrate the successful ejection of the level wafer therefrom;</li><li>Figure 83 is an isometric view of another modification of the multiple level user and master key system embodiment shown in Figure 68;</li><li>Figure 84 is' a cross-sectional view of the number 6 pin and chamber position of the lock shown in Figure 8₃ with the first level wafer therein positioned for removal therefrom;</li><li>Figure 85 is a cross-sectional view similar to that of Figure 84, but with the cylinder rotated to engage the level wafer to be removed;</li><li>Figure 86 is a cross-sectional view similar to Figures 84 and 85, but with the cylinder rotated in reverse direction to illustrate the operational removal of the first level wafer therefrom;</li><li>Figure 87 is a cross-sectional view similar to Figures 84, 85, and 86, but with the cylinder rotated a sufficient amount in the reverse direction to successfully eject the first level wafer therefrom;</li><li>Figure 88 is an isometric view of the cylinder and driver pins of another embodiment of the multiple level user and master key system of the present invention for use with latch mechanisms that do not accommodate 180⁰ rotation of the cylinder;</li><li>Figure 89 is a side elevation view of the multiple level user and master key system shown in Figure 88 with the operating mechanism therein illustrated in broken lines;</li><li>Figure 90 is a side elevation view similar to Figure 89, but with the first user level wafer positioned for removal therefrom;</li><li>Figure 91 is a cross-sectional view taken along line 91-91 of Figure 90;</li><li>Figure 92 is a cross-sectional view taken along line 92-92 of Figure 90;</li><li>Figure 93 is a cross-sectional view similar to that shown in Figure 91, but with the cylinder rotated 90° to effect the removal of the top level user wafer therefrom;</li><li>Figure 94 is a cross-sectional view similar to Figure 92, but with the cylinder rotates to a position corresponding to that shown in Figure 93;</li><li>Figure 95 is a side elevation view of the multiple level user and master key systems shown in Figures 88, 89, and 90, but with the top master level wafer positioned for removal therefrom;</li><li>Figure 96 is a cross-sectional view taken along line 96-96 of Figure 95;</li><li>Figure 97 is a cross-sectional view taken along line 97-97 of Figure 95;</li><li>Figure 98 is a cross-sectional view similar to Figure 96, but rotated 90° to show the maintenance of the user level keying during changing of the master level keying; and</li><li>Figure 99 is a cross-sectional view similar to Figure 97, but with the cylinder rotated 90° to show the removal of the top master level wafer therefrom to effect rekeying of the master level keying system.</li></ul>

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

This invention is directed to rekeyable multiple level user and master key lock systems, including high security embodiments thereof. Throughout the description of this invention in this specification, various configurations of keys are described to illustrate the structure and operation of this invention. Therefore, in order to provide standard terms for this description and to minimize repetitious definitions of key structures, Figure 1 is included to illustrate a typical key K as used in this invention. The structure of key K is known in the prior art and has a head or handle portion H to facilitate grasping by a person's fingers and an elongated shank S extending therefrom. On one side of the shank S i_E a typical bitting configuration for a six-pin cylinder lock. The bit positions in the shank S for corresponding pin positions are conventionally numbered from 1 to 6 beginning at the end of the handle H and extending outwardly to the distal end of the shank S. Thus, the first position or bit 1 is nearest the handle, and bit 6 is the farthest from the handle H.

The vertical depth-of each bit is customarily called a "cut". The cuts generally are indicated as increments of whole numbers designating the relative depth of the cuts for each bit. It is customary for such cuts to range from 0 to 9, with each increment being approximately 0.015 inches. Under this convention, as illustrated in Figure 1, a 0 cut has no vertical depth from the side surface of the shank S. A 1 cut has approximately 0.015 inches of material removed from a bit space, a 2 cut has approximately 0.030 inches of material removed from the bit space, thus proceeding to a 9 cut which has approximately 0.135 inches of material removed from each space.

For purposes of this invention, removable pin wafers are positioned in the pin chambers of a tumbler pin lock for setting the keying combination of the lock. While it is possible for such wafers to be sized corresponding to single <img file="EP0210037A2_D0001.tif" />increments in thickness, such thin wafers are not very practical in durable, reliable rekeyable lock systems. It has been found preferable to size these removeable wafers with a thickness corresponding to at least 2 increments of cut. Thus, Figure l'illustrates only the odd numbered cuts 1, 3, 5, 7, and 9.

For simplicity, in descriptions of individual bits on the key bitting configurations to be described herein, each bit will be described with the format of the "bit number/cut number." For example, a first bit position with a 1 cut will be described as Bl/lC. Likewise, a sixth bit with a 9 cut will be described as B6/9C.

One of the significant concepts of this invention is a rekeyable tumbler pin cylinder type lock system which includes both a plurality of user level rekeying options as well as a plurality of master level rekeying options, wherein such rekeying options are attainable externally without having to disassemble the lock. Further, it is significant that the user levels and master levels can be r_ekeyed according to this invention independent of each other. In other words, this lock system can be operated or opened with a user key as well as with a differently configured master key. The keying combination for the user key can be changed externally, thus changing the lock to require a different user key without affecting the operation of the master key. Likewise, the master key level can be changed or rekeyed externally to require a different master key without affecting the operation of the user key. A number of user key level rekeying options are available as well as a number of master rekeying level options being available.

The basic form and structure of this multiple level user and master rekeyable lock is best illustrated initially by reference to Figures 4 and 6. Figure 4 is a cross-sectional view in side elevation of the rekeyable lock 10 of this invention with a first level user key Ul positioned therein. Figure 6 is a similar cross-sectional view of the rekeyable multiple level and master key lock according to the present invention with the first level user key U1 in the cylinder 20 rotated 180⁰, as it is operated in a normal manner.

The lock 10 includes a lock housing or shell 12 having an upper chamber 30 and a lower section 14. The upper chamber 30 has a plurality of vertical bore holes 51, 52, 53, 54, 55, 56 extending upwardly therein in spaced apart relation to each other from the lower housing 14. Each bore hole or upper chamber 51, 52, 53, 54, 55, ₅6 has positioned therein respectively slideable driver pins 31, 32, 33, 34, 35, 36, which are biased downwardly by respective coiled compression springs 61, 62, 63, 64, 65, 66. The lower chamber 14 is essentially cylindrical and is adapted to slideably and rotatably receive therein the lock rotor or cylinder 20. The lock cylinder 20 is retained in the lower housing portion 14 by an end cap 25 screwed onto the end of the cylinder 20.

The lock cylinder 20 has a keyway 90 extending longitudinally therethrough, which is adapted to slideably receive therein the shank S of a key, such as the first level user key Ul illustrated in Figure 4. The cylinder 20 also includes six transverse bores or chambers in which are slideably positioned respectively the service pins 21, 22, 23, 24, 25, 26. These service pins are sized such that when they register in the appropriately aligned bittings of the key Ul, they raise the driver pins 61, 62, 63, 64, 65, 66 therein to appropriate heights such that the interfacing surfaces between the driver pins and service pins align with the shear line 100. The shear line 100 is defined by the circumferential interface between the cylinder 20 and the housing 14. When such alignment is obtained, of course, the cylinder 20 can be rotated to operate the particular latch mechanism (not shown) to which the lock 10 is connected.

The above description is essentially background information to aid in the understanding of the structure and operation of this .invention. The significant features of this invention for purposes of the multiple level user nnd master key rekeying options are illustrated in Figure 4 as the stack of four short pins or wafers 71, 72, 73, 74, the second stack of two short pins or wafers 81, 82, and the single wafer 80. It is significant to note that with the first level user key Ul positioned in the keyway 90, the stack of four user level change wafers 71, 72, 73, 74 are all positioned below the shear line 100, while the stack of two master level change wafers 81, 82 are both positioned above the shear line 100.

In this illustration, the four wafers 71, 72, 73, 74 are used to rekey the user level keying combinations and are positioned in the cylinder 20 between the sixth service pin 26 and the sixth driver pin 36. The wafers 81, 82 are considered the master key rekeying wafers and are positioned between the fifth service pin 25 and the fifth driver pin 35. The permanent master wafer 80 is positioned between the first service pin 21 and the first driver pin 31 and is illustrated above the shear line 100 with the first level user key U1-in position. It should be noted that while these wafers are positioned in the first, fifth, and sixth positions as described above, they can be positioned in any of the other positions or chambers as well. There can also be different numbers of these user and master level change wafers, as long as there is sufficient space in the pin chambers to accommodate them. However, for the purposes of describing this invention, the user key Ul is considered to work off the shear line at the top of the stack of user level wafers·71, 72, 73, ₇₄ and off the shear line at the bottom of the stack of master level wafers 81, 82. It will also be seen in the description below that the master keys, on the other hand, work off the shear line at the bottom of the stack of user wafers 71, 72, 73, 74 and the top of the master wafers 81, 82. However, it is understood that these working shear lines can be inverted such that the user keys work off the shear lines at the bottom of the user wafers and the top of the master wafers while the master keys work off the shear lines at the top of the user wafers and the bottom of the master wafers if desired. Likewise,_' while this description will proceed with the permanent master wafer 80 positioned above the shear line 100 for the user keys and below the shear line 100 for the master keys, this configuration could be inverted as well.

Also, for the purposes of describing this invention, four user wafers 71, 72, 73, 74 have been chosen to provide five different user level keying combinations and two master wafers 81, 82 provide three different master level keying combinations. These numbers of wafers can be varied to provide different numbers of keying combinations, but this illustration is considered to be adequate and practical for most applications.

It is also noted, for purposes of this description, that each user and master wafer is approximately the thickness of two level cuts in the key. Therefore, this first user level key Ul is illustrated with the following bitting: Bl/3C, B2/7C, B3/SC, B4/7C, B5/1C, and B6/9C. (For a definition of these designations of bit positions and cuts, see the explanation above.) As shown in Figures 4 and 5, this key bitting combination of the first level user key Ul is effective to position all of the user wafers 71, 72, 73, 74 below the shear line 100 and the master wafers 81, 82, as well as the permanent master wafer 80, above the shear line 100. Also, as illustrated in Figures 4 and 5, this lock combination with this first level user key U1 is in a position to be opened, i.e., the cylinder 20 can be rotated by the key Ul.

Figures 6 and 7 illustrate the lock described above and shown in Figure 4, but with the first level user key _Ul and the cylinder 20 rotated 180⁰, as the lock 10 is operated or opened. It can be seen in the positions illustrated in Figures 6 and 7 that when the cylinder is rotated 180°, the spine SP of the key shank holds the driver pins 31, 32, 33, 34, 35, 36 with their respective bottom surfaces at the-shear line 100 to allow continued operation of the lock from this 180° rotated position. Therefore, the user level key Ul can then be rotated from the position illustrated in Figures 6 and 7 back to its original position as illustrated in Figures 4 and 5 when the lock has been opened and the user desires to pull the key Ul out of the cylinder 20.

The operation of the first level master key Ml is illustrated in Figures 8 and 9, wherein the first level master key Ml is shown inserted into the keyway 90 in cylinder 20. This first level master key Ml has the following bitting configuration: B1/7C, B2/7C, B3/5C, B4/7C, B5/5C, and B6/lC. In this configuration; as briefly described above, all of the user level wafers 71, 72, 73, 74 are raised by the sixth bit B6/1C into the upper chamber above the shear line 100. The fifth bit B5/5C allows the master level wafers 81, 82 to drop below the shear line 100., Thus, as mentioned above, when this first level master key Ml is used in the lock 10, it works off the shear line at the top of the service pin 26 and the bottom of the stack of user wafers 71, 72, 73, 74 and off the shear line at the bottom of the drive pin 35 and the top of the master level wafers 81, 82.

The first bit B1/7C of this first level master key Ml allows the permanent master wafer 80 to drop below the shear line 100 so that it works off the shear line at the bottom of the driver pin 31 and the top of the permanent master wafer 80. The illustrations herein show the permanent master wafer 80 as having a thickness equal to four cut increments, thus requiring the difference of four cut levels between the first bit B1/3C and the user key U1 and the first bit B1/7C and the master key Ml. As shown in Figures 8 and 9, this bitting combination of the master key Ml aligns all of the shear lines in each of the pin chambers so that the cylinder 20 can be rotated to open the lock, which rotation is shown in Figures 10 and 11. As illustrated in Figures 10 and 11, the spine SP of the first level master key Ml maintains the shear line 100 when the cylinder is rotated 180° to allow the cylinder 20 to again be rotated away from this open position to the closed position where the master key Ml can be pulled out of the cylinder 20.

The user level rekeying option is best described by reference first to Figures 12 and 13, wherein a second level user key U2 is shown positioned in the lock. This second level user key is bitted different than the first level user key Ul in the sixth bit. Specifically, the sixth bit of this second level user key U2 is B6/7C, as opposed to the B6/9C of the first level user key. This second level user key U2 also has a notch 96 recessed into its spine SP. This notch 96 is in transverse alignment with the sixth bit B6/7C and with the sixth service pin 26 and driver pin 36 in the lock 10. In this position, as illustrated in Figures 12 and 13, the first user level change wafer 71 is pushed above the shear line 100 by the sixth bit B6/7C of the second level user key U2.. Thus, the operating shear line for the sixth position is between the first and second user level wafers 71, 72. However, as described above for the first level user key Ul, the fifth bit B5/lC of this second level user key U2 still pushes all of the master wafers 81, 82 above the shear line 100 so that the working shear line in the fifth chamber is under the master level wafers 8l, 82 This configuration is consistent with the description above wherein the user keys all work off a shear line under the master level rekeying wafers 81, 82. Further, the first bit _Bl/3C of this second level user key U2 also raises the permanent master wafer 80 above the shear line 100 as did the first level user key Ul described above. Therefore, as illustrated in Figures 12 and 13, the shear line 100 is unbroken, thereby allowing the cylinder 20 to be rotated 180⁰ to the position illustrated in Figures 14 and 15.

When the second level user key U2 is used as described above to rotate the cylinder 20 180° to the positions shown in Figures 14 and 15, the first level changing wafer 71 is pushed by spring 66 into the notch 96 in the spine SP of the key U2. This notch 96 is recessed into the spine SP a distance equal to the thickness of the wafer 71, i.e., the thickness of a two cut. Therefore, when the wafer 71 is positioned in the notch 96, the shear line 100 is maintained between the top of the wafer 71 and the bottom of the driver pin 36. Consequently, the key U2 can then be used to again rotate the cylinder 20 180⁰ back to its original position as shown in Figures 16 and 17.

When the rotor 20 is rotated back to the original position as shown in Figures 16 and 17, the first level user wafer 71 is captured by the notch 96 and carried out of the sixth pin chamber to the bottom of the cylindrical housing 14. Therefore, only three user level wafers 72, 73, 74 remain in the sixth pin chamber. When the second user level key U2 is pulled out of the keyway in this position, the first level user wafer 71 is ejected out of the lock, as more fully described in my previously issued U.S. Patent Nos. 4,412,437, and 4,440,009. The result is that the sixth bit B6/7C of the second level user key U2 operates off the shear line above the second user level wafer 72 as shown in Figures 16 and 17. However, as shown in Figures 18 and 19, the sixth bit B6/9C of the first level user key Ul is no longer high enough to provide a shear line across the sixth chamber. Therefore, the spring 66 pushes the sixth driver pin 36 across the shear line 100 into the chamber in the cylinder 20, thereby effectively preventing any rotation of the cylinder 20 in the housing 14. The result of this key change with the second level user key U2, as described above, is that the first level user key Ul is no longer operable in the lock 10.

However, as illustrated in Figures 20 and 21, the above-described user level change accomplished with the second level user key U2 does not affect the operation of the lock 10 with the first level master key Ml. On the contrary, the first level master key Ml still is capable of operating the lock 10 in spite of the user level change because the master keys operate off a shear line under the stack of user level change wafers 72, 73, 74 and off a shear line on the top of the master level change wafers 82, 83. More specifically, the sixth bit B6/lC of the master key Ml pushes the user level wafer 72 73, 74 above the shear line 100 and works off the shear line on the top of service pin 26, rather than on the bottom of driver pin 36.

Another significant feature of this invention is illustrated in Figures 22 through 26. In this illustration, after the second level user key U2 has been used to eject the first user level wafer 71 out of the lock, as described above, this key is reinserted into the lock 10 and rotated 180⁰. As shown in Figures 22 and 23, this position allows the sixth driver pin 36 to drop into the notch 96. In similar prior art rekeyable locks, this occurrence would have caused the second level user key U2 to become jammed or locked in the cylinder 20 by the driver pin 36 so that it could not have been withdrawn and the cylinder 20 could no longer have been turned. Such an occurrence in the prior art rekeyable locks would effectively disable the locks and ruin them for all practical purposes. Therefore, in prior art locks having similar mechanisms with full-sized notches similar. to the fall- sized notch 96 shown in Figure 22, it was essential once the second level user key was used to capture and eject the first level wafer from the lock, to be sure that key is never inserted into the lock and rotated 180⁰ again.

In the configuration of this invention, however, this problem is alleviated by the provision of bevelled surfaces 92, 94 along the longitudinal opening of the keyway at the peripheral surface of the cylinder. This feature is also illustrated in the isometric exploded view of the lock cylinder 20 in Figure 2 with the second level user key U2 positioned therein. With these bevelled edges 92, 94 of the keyway 90, as opposed to the straight sides of prior art locks, the cylinder 20 can be rotated out of this position, even if the driver pin 36 does drop into the notch 96. Such rotation after the driver pin 36 has been dropped into the notch 96 is illustrated in Figures 24-26. When the cylinder 20 is rotated as shown in Figure 24, the bevelled edge 92 cams the driver pin 36 upwardly against the bias of the spring 66 until it is clear of the keyway 90 as shown in Figure 25. Therefore, the cylinder 20 can be rotated again the remainder of the 180° to its normal position shown in Figure 26. Once the normal position of Figure 26 is reached, the key U2 can, of course, be pulled out of the cylinder 20.

The result and effect of this feature is that a user need no longer be concerned about whether the second level key U2 has already been used to remove the first level wafer 71. The user can, with impunity, reinsert the second level user key U2 and rotate it 180° as many times as he desires, for example, to see whether that change level has already been rekeyed. If the notch 96 captures a wafer and ejects it from the lock, then it was not rekeyed at that level before but is with this operation. If it does not capture a wafer and eject it from the lock, then it can be inferred that that level change had been made previously.

This feature also eliminates the requirement to have a different second level user key for continuous use by the user that does not have the notch 96 in the spine SP. In this lock according to this invention, the user can continue to use the second level user key U2 with the notch 96 therein for opening the lock if he so desires without fear of the sixth driver pin 36 jamming the user key U2 in the lock.

With a change in the user level keys having been described above, a change in the master level keys is now described by reference to Figures 27 through 34. Specifically, in Figures 27, and 28, a second level master key _M2 is shown inserted into the cylinder 20 of the lock 10. This second level master key M2 has a bitting combination as follows: Bl/7C, B2/7C, B3/5C, B4/7C, B5/3C, and B6/1_C. Like the first level master key Ml, this second level master key M2 has a sixth bit B6/1C that raises all of the user level change wafers 72, 73, 74 above the shear line 100 and operates off the shear line on top of the sixth service pin 26. Also, like the first level master key Ml, the second level master key M2 has a first bit B1/7C that drops the permanent master wafer 80 below the shear line 100 and works off the shear line on top of the permanent master key 80. However, this second level master key M2 has a fifth bit B5/3C that is two cuts higher than the fifth bit B5/5C of the first level master key Ml. Therefore, this fifth bit B5/3C pushes the top master change wafer 81 above the shear line 100 and works off the shear line at the top surface of master change wafer 82.

This second level master key M2 also has a notch 98 recessed into its spine SP a distance equal to the thickness of the level, change wafers 81, 82. This notch 98 is transversely aligned with the fifth bit on the key M2 and with the fifth service pin 25 and fifth driver pin 35 in the lock 10. Therefore, when the cylinder 20 is rotated 180°, as shown in Figures 29 and 30, the first level master change wafer 81 is pushed by spring 65 into the notch 98. Since the depth of the notch 98 is equal to the thickness of the wafer 81, a continuous shear line 100 is maintained over the top surface of the wafer 81. Then, the master key M2 and cylinder 20 can be reverse rotated 180° back to the original position as shown in Figures 31 and 32, thereby capturing and carrying the wafer 81 to the bottom of the housing 14. In this position, the key can be pulled out of the cylinder 20 to eject the first level master change wafer 81 from the lock 10. With the completion of this operation, the change of the master keying combination to the second level is accomplished. Then. as shown in Figures 33 and 34, the fifth bit B5/5C of the first level master key M1 is no longer effective to raise the service pin 25 to a shear line. Consequently, the fifth driver pin 35 interrupts the shear line 100 as shown in Figures 33 and 34 and prevents the first level master key Ml from operating the lock 10.

However, as illustrated in Figures 35 and 36, the change of the master.keying to the second level configuration of key M2 does not affect the operation. of the lock with the second level user key U2. The user key U2, like the other user keys, works off the shear line at the bottom of driver pin 36 and at the top of service pin 25 so that the ejection of the first level master wafer does not affect the operation of the user keys.

The above description, in conjunction with the figures discussed therein, describes and illustrates the change of a user key level independently of the master key operation, and it illustrates and describes the change of a master level keying configuration without affecting the user key operation. Therefore, a lock 10 constructed according to this invention provides the benefit of multiple level rekeying of user keys as well as multiple levels of rekeying master keys independently of each other.

Since the principles, structure, and operation of the lock 10, including first level rekeying for both the user and master keys, are described and illustrated above, it is not considered necessary to describe or illustrate in such detail the similar operation for changing additional user and master key levels by ejecting additional user or master change wafers. Persons skilled in the art should now readily understand how the additional user and master level rekeying of the lock 10 is accomplished. It is believed sufficient to insure an understanding by persons skilled in the art to merely illustrate the third level user key in Figure 7 and the fourth level user key in Figure 38. The third level user key U3 in Figure 37 has the following bitting: Bl/3C, B2/7C, B3/5C, B4/7C, B5/1C, and B6/5C. The fourth level user key U4 shown in Figure 38 has the following bitting: B1/3C, B2/7C, B3/SC, B4/7_C, B5/lC, and B6/3C. These third and fourth level user keys are, of course, used to eject the respective third level and fourth level user change wafers 73, 74 from the lock 10 to accomplish the third and fourth level user rekeying.

It is considered beneficial to illustrate the final level changes of both the user and master keys to illustrate the purpose of the permanent master wafer 30. As shown in Figures 39 and 40, the fifth and final level user key U5 is positioned in the lock 10. This fifth level user key U5 has the following bitting: Bl/3C, B2/7C, B3/5C, B4/7C, B5/lC, and B6/lC. This fifth level user key U5 with its sixth bit B6/lC raises the service pin 26 to utilize the shear line at the top of service pin 26. In this position, the fourth user level change wafer 74 (not shown in Figure 39) is raised above the shear line 100, and can be captured in notch 96 and removed from the lock, similar to the procedure described above for the lower user level keys. For the purposes of this illustration in Figures 39 and 40, it is understood that the fourth level user change wafer has already been removed from the lock 10 by the fifth level user key U5. Likewise, the illustration in Figures 41 and 42 show the third level master key M2 inserted in the lock 10 with the second level master change wafer 82 having already been removed as described above for the lower level changes.

The result of all of the level changes is that the lock 10 is left with only the permanent master wafer 80 in the lock as shown in Figures 39 through 42. Further, with the exception of the first bit, the final levels of the user and master keys (illustrated here with user key U5 and master key M3) both have the same bittings. In other words, both the final level user key U5 and the final level master key M3 have the following bitting in common: B2/7C, B3/5C, B4/7C, B5/1C, 86/lC. Consequently, if the first bits in the keys U5 and M3 were also the same, the final level user key U5 would become a master key able to open all of the locks in the system.

In order to eliminate this problem, the permanent master wafer 80 is utilized with a different first bit in the user and master keys. As illustrated in Figures 39 through 42, the fifth and final level user key U5 has a first bit Bl/3C, which raises the permanent master wafer 80 above the shear line 100 and operates off the shear line at the top of the first service pin 21. The third and final level master key M3, however, has a first bit _B1/7C which leaves the permanent master wafer 80 below the shear line 100 and operates off the shear line at the bottom of the first driver pin 31. This feature keeps all the user keys separate from the master keys in a lock system.

Before concluding the description of this embodiment of the invention, it is appropriate to reiterate that the feature illustrated for the second level user key U2 in Figures 22 through 26 wherein that key can be reinserted and used as many times as desired without fear of the driver pin dropping into the keyway 90 via the notch 96 to jam the lock is equally applicable to both the remaining higher level user keys U3, U4, and U5, as well as to the higher level master keys M2, M3. Thus, it is always appropriate with this rekeyable lock to continue using the level change key to open the lock as often as desired. It is also acceptable to use any particular level change key to check whether that level change has already been made by trying it in the lock and seeing whether it will eject a wafer.

Another variation of this feature is illustrated in Figure 3 for use in a well-known higher security lock. For purposes of explanation and understanding of the necessity of this variation for this type of lock, a brief description of the operation of such a lock is provided for those persons unfamiliar with it. Such a prior art high security lock modified for rekeyable capabilities according to this invention is illustrated in Figure 3. The service pins 121, 122, 123, 124, 125, and 126 index with the bittings on a key K to raise the driver pins 131, 132, 133, 134, 135, 136 against the bias of springs 161, 162, 163, 164, 165, 166 to establish a consistent shear line at the peripheral surface of the cylinder 120. However, in addition to such normal indexing, the service pins 121, 122, 123, 124, 125, 126 also have in their respective lateral sides longitudinal grooves 141, 142, 143, 144, 145, 146 therein. The cylinder 120 also has an elongated slot 175 in its side into which an elongated bar 174 is slideably inserted. This bar 174 is biased outwardly by two small coil compression springs 176, 178. When the bar 174 extends outwardly beyond the peripheral surface of the cylinder 120, an obstruction in the lock housing (not shown) prevents the cylinder 120 from being rotated, thus preventing the operation of the lock. However, in order for the bar 174 to be fully inserted into the slot 175 so that it does not interfere with rotation of the cylinder 120, the longitudinal grooves 141, 142, 143, 144, 145, 146 must be aligned transversely to the longitudinal axis of the cylinder 120 so that they can receive the short fingers 151, 152, 153, 154, 155, 156 on the inside surface of the bar 174. If any of the service pins 121, 122, 123, 124, 125, 126 is rotated within the cylinder 120 so that its longitudinal groove is not transverse with the longitudinal axis of the cylinder 120, thus cannot receive the respective finger 151, 152, 153, 154, 155, or 156 on the bar 174, then the bar 174 is prevented from being fully inserted into the slotted opening 175 so that the cylinder 120 cannot be turned in the lock housing (not shown).

In order to effect this alignment of the longitudinal slots, each service pin 121, 122, 123, 124, 125, 126 has a slanted surface thereon 111, 112, 113, 114, 115, 116, respectively. The key bitting also has corresponding slanted surfaces thereon which index with the slanted surfaces on the service pins to rotate the service pins within their respective chambers in the cylinder 120 to properly align the longitudinal grooves 141, 142, 143,-144, 145, 146 to receive the fingers 151, 152 153, 154, 155, 156 on the bar 174. Therefore, in order to open this lock illustrated in Figure 3, two conditions must be met.

First, the service pins 121, 122, 123, 124, 125, 126 must be raised the appropriate distances to create the shear line under driver pins 131, 132, 133, 134, 135, 136 in alignment with the peripheral surface of the cylinder 120. Second, the service pins 121, 122, 123, 124, 125, 126 must also be rotated so that the respective grooves 141, 142, 143, 144, 145, 146 can receive therein the fingers 151, 152, 153, 154, 155, 156 on the inside of the bar 174.

This type of lock, as shown in Figure 3, can be equipped with user and master level change wafers according to this invention as described above. For example, as shown in Figure 3, four user level change wafers 171, 172, 173, 174 are positioned between the service pin 126 and the driver pin 136. Also similar to the invention described above, two master level change wafers 181, 182 are positioned between the fifth service pin 125 and the fifth driver pin 135. Finally, as described for this invention above, a permanent master wafer 180 is positioned between the service pin 121 and the driver pin 131. Therefore, with these multiple level change wafers and the permanent master wafer in this high security lock, it can be used as described for the preferred embodiment above, to rekey multiple user levels and mutiple master levels independently of each other.

It has been found, however, that in this type of high security lock, the level change wafers are not sufficiently confined by the bevelled edges 92, 94 shown in Figure 2 The side bar hole 175 tends to dislocate the wafer pins in such a keyway channel with bevelled edges 92, 94. Such dislocation can jam the lock. Therefore, the modification illustrated in Figure 3 includes tapered pockets having opposite sides 192, 194 in the straight edges 193, 195 of the keyway 190 under the sixth driver pin 136. A similar round, tapered pocket is provided under the fifth driver pin 135 having rounded, tapered opposite sides 197, 198 in the straight edges 193, 195 of the keyway 190. These pockets more effectively capture and retain a wafer, such as wafer 171, in the notch 196 from moving longitudinally in the keyway 190 during rotation of the service pin 126. Consequently, this bevelled edge pocket configuration is more reliable than the elongated bevelled edge configuration shown in Figure 2, especially for locks in which the service pins are rotatable. Of course, this round, tapered pocket arrangement can also be'used in the preferred embodiment of Figure 2 described above instead of the elongated tapered edges 92, 94.

As mentioned above, additional user and master levels can be made by adding additional level change wafers to additional chambers in the lock. Such additional lock configurations would, of course, continue to allow level changes as well as master changes independently of each other if the principles described above for this invention are followed. However, while such multiple level rekeying capability as described above have many beneficial attributes, they can also cause a significant decrease in the security of the lock. For every additional rekeying level provided, an additional possible shear line is also provided. Such multiple shear lines, of course, render such a lock much more susceptible to picking or unauthorized opening. Therefore, this invention includes additional embodiments and variations that provide increased security and resistance to picking or unauthorized opening, which are described in detail below.

As background information, the most common method used by lock pickers in picking locks is to insert a tool into the keyway of the lock and hold a rotational bias on the cylinder while manipulating the pins in the keyway with a second tool. When such rotational bias is maintained on the cylinder, an adept lock picker can "feel" ever so slight a movement in the cylinder when a shear line has been found. Then, once such a shear line is found, the rotational'bias maintained on the cylinder is also effective to hold the aligned pins in the'shear line position while the lock picker moves on to the next pin to find the next shear line. Therefore, elimination of the lock picker's ability to "feel" the shear lines as the pins are manipulated increases the security of the lock.

The illustrations in Figures 43 and 44 show one method of eliminating a lock picker's ability to feel some or tne snear lines created oy the addition of muitipie level changing wafers into the lock as described above. As shown in Figures 43, 44 the four user level change wafers 71, 72, 73, 74 are glued together in a stack with a frangible glue material. The glue lines 201, 202, 203 retain the four wafers 71, 72, 73, 74 in a rigid column that has the practical effect of one elongated pin with only a shear line on the top of pin 71 and another on the bottom of pin 74, rather than the five actual shear lines contained in the stack. Therefore, when this stack of four wafers is positioned in the lock, a lock picker with his tools cannot feel the intermediate shear lines at the glue lines 201, 202, 203. However, when the change level key is inserted and operated in the lock, the glue line that is aligned with the shear line of the lock can be broken. Once the glue line is broken, the water can be removed from the lock in the manner described above.

The variation of this rigid stack of wafers 204 shown in Figures 45 through 48 essentially have the same i functional effect as the glued wafer stack 204 shown in Figures 43 and 44. However, the embodiment 204 shown in Figures 45 and 46, the individual wafers 71, 72, 73, 74 have hollow cores through which a solid frangible core of graphite 205 is inserted. This solid graphite core 205 retains the individual wafers 71, 72, 73, 74 in the stack. Again, a lock picker cannot feel the intermediate shear lines between these wafers because the wafers are prevented by the graphite core 205 from moving in relation to each other. However, sufficient pressure on a level change key can break the graphite core 205 at the appropriate shear line when the level is being changed according to this invention as described above. The broken graphite core 205 also has the additional advantage of lubricating the lock internally whenever the keying level is changed.

The wafer stack 206 illustrated in Figures 47 and 48 utilizes a sleeve of solid, frangible material 207 that holds the stack of wafers 71, 72, 73, 74 together. This sleeve 207 is also preferably a graphite material.

As is clearly illustrated in the cross-section of Figure 48, in this embodiment 206 the individual level wafers 71, 72, 73, 74 are stacked inside the cylindrical sleeve 207. Therefore, until individual wafers are removed for changing the keying combination levels, the shear lines between the wafers 71, 72, 73, 74 cannot be felt by a person picking the lock. However, when an individual wafer, such as the top wafer 71, is raised above the shear line for removal to change the keying level, as illustrated in Figures 12 and 13, the shear line between wafers 71 and 72 is aligned with the shear line 100 of the lock. Then, when the cylinder is turned with the key, the frangible sleeve 207 will break and shatter at the shear line between wafers 71 and 72 to allow the top wafer 71 to be removed from the stack as described above. Again, as with the embodiment 204 shown in Figures hance the operation of the lock.

This wafer stack embodiment 206 illustrated in Figures 47 and 48 utilizes wafers that are smaller in diameter than the pin chambers in order to provide sufficient space for the sleeve 207. Consequently, this embodiment is particularly appropriate for use in rekeyable lock embodiments that utilize smaller diameter pins, such as the alternate embodiment of this invention shown in Figures 88 through 99 and described below, as well as in rekeyable lock apparatus such as that described in my previously issued U.S. Patent No. 4,412,437. When the top pin is sheared from the remainder of the stack in this embodiment, the graphite sleeve 207 around the pin to be removed completely shatters, leaving the effective diameter of the actual pin to function as described in those embodiments for selective removal thereof.

A higher security lock embodiment of the present invention is shown in Figures 49 through 58. In this high security lock embodiment, referring first to Figure 49, three of the service pins 212, 213, 214 in the cylinder 220 that are not being utilized for rekeying or master levels have transverse slots or openings 292, 293, 294, respectively, in their upper ends. The driver pins 232, 233, 234 in the corresponding second, third, and fourth positions have transverse narrow protrusions or cotters 302, 303, 304 protruding from the respective bottoms of the driver pins 232, 233, 234. These protrusions or cotters 302, 303, 304 are sized and shaped to be received into and engage the respective slots or openings 292, 293, 294 in the tops of the service pins 212, 213, 214.

The remaining driver pins 231, 235, 236 and corresponding service pins 211, 215 and the service pin in the sixth position (not shown) are utilized in this embodiment much the same as the corresponding pins in the first, fifth, and sixth positions described above in the preferred embodiment illustrated in Figures 4 through 42. In other words, these pin positions include the rekeyable user and master level features described above. For example, the permanent master wafer 280 in position number one corresponds to the permanent master level wafer 80 illustrated in the preferred embodiment above. Likewise, the master level change wafers 281, 282 in Figure 49 correspond to the similar master level change wafers 81, 82 in the preferred embodiment illustrated above. The user level change wafer 271 in the sixth position in Figure 49 corresponds to the similar user level change wafer 71 described in the preferred embodiment above.

The remaining user level change wafers in Figure 49 are positioned in the sixth pin chamber in the cylinder 220 under the wafer 271 so that they cannot be seen in this illustration. However, even though the-additional user level change wafers are not shown in Figure 49, it is understood that they can be utilized there as in the preferred embodiment described above. Likewise, the driver springs 261, 262, 263, 264, 265, 266 bias the respective driver pins 231, 232, 233, 234, 235, 236 downwardly toward the cylinder 220, as described in the preferred embodiment above.

It should be noted in referring to Figure 49 that the orientation of the slots 292, 293, 294 in the service pins 212, 213, 214 and the corresponding cotters 202, 203, 204 in the respective driver pins 232, 233, 234 are "scrambled" or oriented at different angles with respect to the longitudinal axis of the cylinder 220. These components assume these scrambled positions when the key is removed from the keyway of the cylinder 220. The purpose for this scrambling of the orientations of the service pins 212, 213, 214 is to prevent the cylinder 220 from being turned in the lock even when all of the shear lines in the pins are aligned. In other words, when any of the cotters 302, 303, 304 and the corresponding slot 292, 293, or 294 of any of the pins is not positioned transverse to the longitudinal axis of the cylinder 220, the cylinder 220 is prevented from rotating in the lock body.

Therefore, in order for the lock to be opened, it is not only necessary to align the shear lines of the pins with the top surface of the cylinder 220, it is also necessary to reorient the respective cotters 302, 303, 304 and corresponding siots 292, 293, 294 transverse to the longitudinal axis of the cylinder 220, as illustrated in Figure 50. In this position illustrated in Figure 50, with the driver and service pins in the second, third, and fourth positions are rotated as illustrated by the arrows to "unscramble" the orientations so that the cotters 302, 303, 304 and corresponding slots 292, 293, 294 are transverse to the longitudinal axis of the cylinder 220 as indicated by center lines 292', 293', 294'. The cylinder 220 can then be turned by the key 290 to open the lock. Of course, the shear lines of all of the pins must also be aligned with the upper surface of the cylinder 220 in the conventional manner to open the lock.

The unscrambling or rotation of the pins in the second, third, and fourth positions, as shown in Figure 50, is accomplished by insertion of a specially configured key 290 having bevelled surfaces in the bittings for the second, third, and fourth positions, as illustrated in Figures 51 and 52. For example, the bitting for the second position of the key 290 has surfaces 222 that are bevelled or slanted at an acute angle to the longitudinal axis of the key, as illustrated by the center line 229 in Figure 52. Similarly, the surfaces 223, 224 of the respective third and fourth bittings of the key 290 are also oriented at an acute angle to the longitudinal axis of the key 290, as illustrated by the center lines 239, 249, respectively. The remaining bittings for the first, fifth, and sixth positions of this key 290 have respective surfaces 221, 225, 226 that are transverse to the longitudinal axis of the key 290 in the ordinary manner, as shown by the respective center lines 219, 259, 269 in Figure 52.

The service pins 212, 213, 214 in the second, third, and fourth positions have essentially flat slanted surfaces or faces to mate with the bevelled surfaces 222, 223, 224 in the key bitting. For example, the pin 214 for the fourth position is illustrated in Figures 53 and 54 having slanted or bevelled bottom faces 247, 248 for mating with the bevelled or slanted surfaces 224 of the key 290. The slots 292, 293, 294 in the tops of the respective service pins 212, 213, 214 are oriented such that when the bevelled faces of those pins are mated with the respective bevelled surfaces in the bittings of the key 290, the slots 292, 293, 294 are positioned transverse to the longitudinal axis of the cylinder 220, as shown in Figure 50. Therefore, when the angle orientations of these slots 292, 293, 294 on the service pins 212, 213, 214 correspond appropriately to the angled or slanted surfaces 222, 223, 224 of the second, third, and fourth bittings of the key 290, then the slots 292, 293, 294 will be properly oriented transverse to the longitudinal axis of the cylinder 220 when the key 290 is inserted into the keyway in the cylinder 220. Of course, when the lock is assembled, the cotters 302, 303, 304 on the driver pins 2₃2, 233, 234 are inserted into and engaged with the slots 2₉₂; 293, 294 in the service pins 212, 213, 214. Consequently, proper orientation of the service pins 212, 21₃, 21₄ will also result in the cotters 302, 303, 304 being oriented transverse to the longitudinal axis of the cylinder 220 as well.

The operation of this high security lock assuming insertion of a properly cut and bitted key 290 in the cylinder 220 is illustrated in Figures 55 through 58. Referring first to Figure 55, a first level user key 290 is shown in the lock 210 of this embodiment. In this illustration, this user key 290 has its first bitting cut to position the permanent master wafer 280 above the shear line 100, its fifth bit cut to position both the master level change wafers 281, 282 above the shear line 100, and the sixth bit cut to position the user level change wafers 271, 272, 273, 274 below the shear line 100. Likewise, the cuts on the second, third, and fourth bittings are such that the shear lines between the respective driver pins and service pins in those positions are also at the shear line 100. Additionally, the slanted surfaces on the bittings of the second, third, and fourth positions of this key 290 are as shown in Figures 51 and 52 to orient the cotters 302, 303, 304 and corresponding slots 292, 293, 294 transverse to the longitudinal axis of the cylinder 220, all as described above.

Figure 56 is an illustration of the lock opening at the fourth position pins, but it is representative of the lock opening at the second and third position pins as well. As described-above, the key 290 is cut in this fourth position bit to position the shear line between the driver pin 234 and the service pin 214 at the shear line 100 on the peripheral surface of the cylinder 220. In addition, the rounded cotter 304 on the bottom of the driver pin 234 is positioned in the slot 294 in the top of the service pin 214. Then, when the key 290 in cylinder 220 begins to rotate in the direction indicated by the arrow illustrated in Figure 57, the rounded surface of the cotter 304 is cammed upwardly by the edge 244 of the cylinder 220 adjacent the slot 294. As the cylinder 220 continues to rotate, as shown in Figure 58, the cotter 304 is cammed and lifted completely out of the slot 294 so that it rides on the peripheral surface of the cylinder 220 as the cylinder 220 is turned to open the lock. In reverse, when the cylinder 220 is rotated in the opposite direction, the cotter 304 on the bottom of driver pin 234 will fall back into the slot 294 in service poin 214 when the driver pin 234 and service pin 214 are again axially aligned with each other.

It is important to understand that if the cotter 304 in corresponding slot 294 had not been oriented by the key 290 to a position transverse with the longitudinal axis of the cylinder 220, as described above, it would have been impossible for the cylinder 220 to have been rotated The cotter 304, which is positioned across the shear line 10₀, would have prevented such rotation. It is only when the cotter 304 and the slot 294 are oriented transverse to the longitudinal axis of the cylinder 220 that the rounded surface of the cotter 304 will be effective to cam the driver pin 234 upwardly over the edge 244 of the cylinder 220 to allow the cylinder 220 to be rotated.

From the above description, it can be appreciated that this configuration provides a much higher degree of security than the preferred embodiment described above tnd illustrated in Figures 4 through 42. One of the significant reasons for such higher security, of course, is that the service pins 212, 213, 214 not only have to be lifted to the appropriate height to align the shear lines with the surface of the cylinder 220, but they all must also be rotated the proper degrees to orient the slots 292, 293, 294 transverse to the longitudinal axis of the cylinder ₂20. Thus, it is very unlikely that an unauthorized person would have a key configured to accomplish all of these functions.

Further, it would be very difficult for an unauthorized person to pick this lock. He would not only have to get the shear lines properly aligned for all six pins, he would also have to get the second, third, and fourth pins 212, 213, 214 all rotated to the proper orientation with respect to the longitudinal axis of the cylinder 220. Such a task would be extremely difficult, if not practically impossible.

It is also significant to note that this lock configuration provides an additional security advantage beyond what can be gleaned from the description above. Specifically, as described above, it is a common practice for most lock pickers to insert a tool into the keyway of the cylinder and apply a rotational torque to the cylinder. Then, while holding that rotational torque, they use a second tool to work on individual pins until a shear line is found. An experienced lock picker can usually tell when the shear line is found on a pin by "feeling" a very slight movement in the cylinder while he is holding the rotational torque thereon when the shear line is aligned. Then, by continuing to hold the rotational torque on the cylinder, those pins will be held in the proper shear line alignment while the picker moves on to the next pin to find the shear line alignment thereof. In this manner, an experienced lock picker can, without too much difficulty, progress usually from the sixth pin to the first pin of a lock sequentially finding the shear lines for each pin position, and thereby attain the opening of the lock.

In the present high security embodiment 210 of this invention, however, the lock picker cannot feel any indication in the lock for aligning the second, third, and fourth pins in their proper rotations. The cylinder will not rotate until' all of the slots 292, 293, 294 are oriented transverse to the longitudinal axis of the cylinder. However, the lock picker has no way of knowing when such orientation of any one of those keys is reached. Further, he cannot feel when a shear line of any of these i pins is reached because the cotters on the driver pins still extend across the shear lines into the cylinder when the shear lines are aligned. The downward pressure of the springs on these three driver pins also inhibits any feeling of shear lines until all three pins are angularly aligned at the same time when they can be cammed together out of the cylinder. Therefore, the lock picker cannot simply manipulate one pin until he finds the proper orientation and shear line and then sequentially move onto the next pins as he can in picking conventional locks. If he cannot get all three pins 292, 293, 294 properly aligned at precisely the same time, for which there is no indication by "feel" in the mechanism of the lock, the lock will not open. Therefore, this high security lock embodiment 210 deprives the lock picker of his most significant aid in picking a lock, that being his "feel" of achieving proper pin alignments in the lock.

As briefly described above, the additional shear lines provided by the numerous user level change wafers 271, 272, 273, 274, as well as the additional master level change wafers 281, 282, the security of such multiple level user and master lock systems is compromised to some extent. However, with the addition of the unique configuration of the second, third, and fourth pin positions with the engaging cotters 302, 303, 3.04, and the corresponding slots 292, 293, 294, the security of such a multiple level rekeyable user and master key system is significantly enhanced. Additionally, when such a lock is also provided with the stacked change wafers illustrated in Figures 43 through 48 above, the security of such a lock is enhanced even more.

Figures 59 and 60 illustrate the high security features of the lock embodiment 210 described above, but without the multiple level rekeyable user and master key system of this invention. If maximum security, rather than rekeying ability, is the primary goal of a lock installation, then the features of this embodiment can be used in all six pin positions, as shown in Figures 59 and 60. In this configuration, all six service pins 211, 212, ₂13, 214, 215, 216 have respective slots 291, 292, 293, 294, 295, 296 in the tops thereof, all of which can be scrambled as indicated by the center lines 291', 292', 293', 294', 295', 296'. When so scrambled, the cotters 301, 302, 303, 304, 305, 306 on the bottoms of the respective driver pins 231, 232, 233, 234, 235, 236 all intersect the shear lines of the lock and prohibit the cylinder 220 from being turned, even when the shear lines of all six pins are properly aligned. Therefore, in order to open this lock, all six service and driver pins must not only have proper shear line alignment with the surface of the cylinder 220, but they must all also be rotated as indicated by the arrows in Figure 60 to get all of the cotters 301, 302, 303, 304, 305, 306 and corresponding slots 291, 292, 293, 294, 295, 296 are oriented transverse to the longitudinal axis of the cylinder 220 as indicated by the center lines 291', 292', 293', 294', 295', -296'. As explained above, it would be extremely difficult and highly unlikely for a lock picker to be able to achieve all of these physical alignments without the benefit of the "feel" of aligning shear lines on which a lock picker normally relies in picking conventional locks.

The key 299 shown in Figures 61 and 62 is illustrative of a key embodiment configured for use in the lock cylinder shown in Figures 59 and 60. In this key embodiment 299, all six bitting positions have respective slanted surfaces 221, 222, 223, 224, 225, 266, as illustrated by the center lines 219, 229, 239, 245, 259, 269. These slanted surfaces in the key bitting correspond to appropriately configured service pins 211, 212, 213, 214, 215, 216, as described above, for orienting the slots 291, 292, 293, 294, 295, 296 transverse to the longitudinal axis of the cylinder 220.

A variation 310 of the high security lock embodiment 210 of Figures 49 through 58 is shown in Figures 63 through 67. Similar to the lock embodiment 210 described above, this variation 310 in Figure 63 includes a cylinder 320 with service pins positioned in key chambers therein. The service pins 311, 312, 313, 314, 315, are shown, while the sixth service pin is positioned in the cylinder 320 under the level change wafer 371, thus not.seen in this Figure 63. The driver pins 331, 332, 333, 334, 335, 336 are positioned above the service pins and are biased downwardly by respective springs 361, 362, 363, 364, 365, 366. A permanent master wafer 380, as well as. master level change wafers 381, 382 are also illustrated. These master and user wafers function in this lock as they do in those embodiments described above: therefore, it is not necessary to describe them again in relation to this embodiment.

The significant difference between this lock configuration 310 in Figures 63 and 64 and the high security embodiment 210 described above is that the cotters 402, 403, 404 on the bottom of driver pins 332, 333, 334 are not rounded on the bottom surfaces. Instead, they are rectangular in shape with square corners on their bottom edges. Therefore, in order to cam the driver pins 332, 333, 334 upwardly as the cylinder 320 is rotated to open the lock 310, transverse slots 342, 343, 344 are provided in the surface of the cylinder 320 adjacent the pins 312, 313, 314. These slots 342, 343, 344 are recessed into the surface of the cylinder 320 a depth approximately equal to the height of the cotters 302, 303, 304 and approximately equal to the depth of the slots 392, 393, 394 in the respective pins 312, 313, 314.

When the orientation of the slots 392, 393, 394 in respective pins.3l2, 313, 314 are scrambled as shown in Figure 63 and illustrated by the center lines 392', 393', 394', the cotters 402, 403, 404 interrupt the shear lines and prevent the lock from being opened. In order to open the lock, an appropriate key 390 has to be inserted into the cylinder 320 with appropriate slanted surfaces in the bittings thereon to orient the service pins 312, 313, 314 so that the respective slots 392, 393, 394 are rotated to positions transverse to the longitudinal axis of the cylinder 320. Such transverse orientationplaces these slots 392, 393, 394 in alignment with the slots 342, 343, 344 in the surface of cylinder 320, as illustrated in Figure 64 by the center lines 392', 393', 394'.

Figure 65 is a cross-sectional view of the lock 310 illustrating the structure and function of the fourth pin position. While this illustration, as well as those of Figures 66 and 67, are directed to the fourth pin position of the lock 310, they are representative of the second and third pin positions of the lock as well.

In Figure 65, the fourth pin position is shown with the service pin 314 oriented so that the slot 394 in the top thereof is positioned transverse to the longitudinal axis of the cylinder 320 to correspond with that same position shown in Figure 64. The key 390 has the top of pin 314 aligned with the shear line 100 in a conventional manner, and the rectangular cotter 404 on the bottom of driver pin 334 is positioned in the slot 394.

As the cylinder 320 begins to rotate in the direction of the arrow in Figure 66, the surface of the slot 344 in the cylinder 320 cams the cotter 404 in driver pin 344 upwardly into the top pin chamber. Then, as the cylinder ₃20 continues to rotate as shown in Figure 67, the cotter 404 is cammed all the way out of the slot 344-to ride on the peripheral surface of the cylinder 320 as the cylinder is rotated to open the lock. When the cylinder 320 is turned back in the opposite direction, the reverse takes place so that the cotter 404 slides back downwardly into the slot 394 in the top of service pin 314 as the service pin 314 and driver pin 334 come into axial alignment with each other. This variation of the high security lock embodiment 210 has essentially the same security advantages as those described above for the embodiment 210 shown in Figures 49 through 58.

It is appropriate to mention that while the bottoms of the slots 342, 343, 344 are shown in Figures 63-67 to surface an angular spaced distance from the service pin chambers to cam the cotters out of the pin chambers in the cylinder, these slots could be extended at the same depth around the cylinder. Such arrangement would retain the security advantage of requiring the proper rotation of the pins in the cylinder to open the lock, but it would lack the above-described feature of having a common resistance in all pins to rising out of the pin chamber in the cylinder at the same time.

Although the rekeyable user and master level features of the high security embodiment 210 and variations thereof described above and shown in Figures 49 through 67 have not been described in significant detail, it should be understood that the level changes can be accomplished according to the detailed description of this invention for the preferred embodiment user and master level lock systems illustrated in Figures 2 through 42.

The above-described lock embodiments require that the particular latch mechanisms to which those lock embodiments are connected allow 180⁰ rotation of the cylinders in order to effect removal of the level wafers via the notch in the spine of the key. However, there are many latch mechanisms to which locks are connected that do not allow full 180° rotation of the cylinder. In such environments, the above-described multiple rekeyable user and master level lock systems could not operate for the rekeyable functions. Therefore, the multiple levels of rekeyable user and master level lock systems described below are modifications of the embodiments described above that are specifically designed to work when connected to latches that do not allow full 180° rotation of the cylinders.

The lock 410 shown in Figure 68 is an embodiment of a multiple level rekeyable user and master key lock according to this invention that can be used with latch systems that do not accommodate cylinder rotation of 180°, but which do have some limited space outside the lock housing 417 into which the level wafers can be ejected. Such an environment is illustrated in Figures 69 and 70 wherein the lock 410 is installed in a typical conventional padlock 492.

The padlock 492 typically includes a main body portion 496 which houses a latch mechanism and the lock. The latch mechanism of the padlock is not a part of this invention, so it is not shown or described in detail. Suffice it to say that it is adapted to engage the hasp 493 wnen in locked condition. The latch mechanism is connected to the lock 410 so that when the proper key 490 is inserted therein, the latch can be opened to release the hasp 493, thus allowing the padlock 492 to be opened.

The lock 410 is typically positioned in an open cavity or space 495 and retained therein by a retainer plate 494. In Figure 70, the bottom of the padlock 492 is illustrated with the retainer 494 removed to show the open cavity 495 into which discarded level wafers can be ejected from the lock 410.

This lock embodiment 410, as shown in Figures 68 and 69, has two openings 485, 486 in the side of lock housing 417 through which level wafers can be ejected from the lock. In the illustrations of Figures 68 through 77, these ejection openings 485, 486 are aligned with and intersect the fifth and sixth pin chambers in the lock so that the description of its rekeying operation can parallel the description of the preferred embodiments above. It should be understood, however, that like those embodiments described above, these rekeying components could be utilized with the other pin chambers as well.

In the side elevation of the lock 410 shown in Figure 71, the internal key and pin configurations are illustrated in broken lines. For consistency with the description of the foregoing embodiments above, the user level change wafers 472, 473, 474 are positioned in the sixth pin chamber, the master level change wafers 481, 482 are positioned in the fifth pin chamber, and the permanent master wafer 480 is positioned in the first pin chamber. The driver pins 431, 432, 433, 434, as well as the service pins 411, 412, 413, 414 and the permanent master wafer 480 in this embodiment all function the same as in those described above for the preferred embodiments illustrated in Figures 2 through 42. Therefore, there is no need for further description of these components for this lock

embodiment 410.

The user and master level rekeying cut combinations described above for the preferred embodiments illustrated in Figures 2 through 42 also apply in general to the rekeying functions of "this embodiment 410, with only several exceptions. Therefore, since the general rekeying principles can be gleaned from the description above, only the unique features of this embodiment will be described in detail herein.

Referring now to Figures 71, 72, and 75, the pin and key configurations illustrated therein are shown with the user level change wafer 471 in position for being ejected from the lock 410 to change the user level keying thereof. Specifically, in the sixth pin chamber, three user level change wafers 471, 472, 473, 474 are shown positioned between the service pin 416 and the driver pin 436. The key 490 in this illustration has a B6/5C sixth bit to position the bottom surface of the top user level change wafer 471 at the shear line 100 on the surface of the cylinder 420. Therefore, the second, third, and fourth user level change wafers 472, 473, 474 are positioned inside the cylinder 420.

As best illustrated in Figures 71 and 72, the ejection opening 486 in the housing 417 is aligned with the user level 471 to be ejected. This ejection opening in wide enough to allow the user level wafer 471 to pass therethrough, as will be described in more detail beluw.

Before proceeding to the description of the user level wafer ejection, reference is made first to Figures 71 and 75 for an illustration of the corresponding positions of the master change wafers in the fifth pin position when the lock is positioned for ejection of a user level wafer 471. Specifically, the master level change wafers 481, 482 are positioned between the driver pin 435 and the service pin 415.

In addition, a double thickness (four cut) blocking wafer 483 is positioned under the master level change wafers 481, 482 and over the service pin 415. The fifth key bit of the key 490 has a B5/lC configuration for positioning the top of service pin 415 and the bottom of blocking wafer 483 at the shear line 100. In this position, the cylinder 420 is free to rotate, as shown in Figure 75, but the ejection opening 485 in housing 417 is effectively blocked by the blocking wafer 483 to prevent ejection of the master level change wafers 481, 482. It should be noted that in this embodiment, the opening 485 is not wide enough to allow the passage therethrough of the blocking wafer 483. Thus, the blocking wafer 483 will be retained in this position while the cylinder 420 is rotated to eject the user level wafer 471 from the lock, as will now be described.

Referring again to Figures 71-74, the ejection of the user level wafer 471 will now be described. First, as described above and shown in Figure 72, the sixth key bit B6/5C has the user level wafer 471 positioned adjacent the opening 486 with the top of the user level change wafer 473 and the bottom of the user level change wafer 471 aligned with the shear line 100 of the lock so that the cylinder 420 can be rotated. Referring now to Figure 73 in particular, as the cylinder 420 begins to rotate as indicated by the arrow, the friction between the user level wafer 471 and the user level wafer 472 tends to drive the user level wafer 472 into the ejection opening 486. This frictional engagement of wafers 471 and 472 is enhanced by the bias of spring 466.

As the rotation of the cylinder 420 continues, as illustrated in Figure 74, the user level wafer 471 is driven through the opening 486 and out of the lock 410. Thus, the keying combination for the user key is effectively changed by this operation. During this entire operation, as mentioned above, the rotation of the cylinder 420 does not affect the master keying combination, because the blocking wafer 483, as illustrated in Figure ₇₅, prevents the removal of any of the master level change wafers 481, 482.

Next, reference is now made to Figures 76-77 to illustrate the operation of changing the master keying combination in this lock embodiment 410. A key 490 having a B5/7C and B6/SC bitting is inserted into the cylinder 420. The B5/7C bitting shown in Figure 76 lowers the blocking wafer 483 and the second master level change wafer 482 into the cylinder 420, thus aligning the first master level change wafer 481 with the opening 485 in the housing 417. This BS/7C bitting also positions the bottom of master level change wafer 481 and the top of master level change wafer 482 in alignment with the shear line 100 so that the cylinder 420 can be rotated. At the same time, the B6/5C bitting shown in Figure 77 positions the remaining user level change wafers 472, 473, 474 in the cylinder 420 with the bottom of driver pin 436 and the top of master level change wafer 472 aligned with the shear line 100 so that the cylinder 420 can be rotated. Then, with the master level wafer 481 aligned with the opening ₄₈5, as shown in Figure 76, and the driver pin 436 blocking the opening 486, as shown in Figure 77, the cylinder 420 can be rotated counter-clockwise to eject the master level wafer 481 from the lock through the opening ₄₈₅, the same as described above for the ejection of the user level wafer.

Additional user and master level changes can be made in this lock embodiment 410 by changing the cuts of the key bittings essentially as described above for the key combination changes of the preferred embodiment illustrated in Figures 4-42. In this alternate embodiment 410, the user keys are also illustrated working off the shear line at the bottom of the driver pin 436 and the top of the service pin 415. At the same time, the master key for this embodiment 410 is illustrated working off the shear line at the top of the service pin 416 and the bottom of the driver pin 435. During use of any user- key, the blocking wafer 483 prevents ejection of any remaining master level change wafers through the opening 485 to preserve the master level keying.

As described above, the ejection of the user and master level change wafers depends on friction to drive the level change wafers through the openings 485, 486 and out of the lock 410. While this structure is quite reliable and efficient, it may be desirable to provide a positive engagement to drive the level change wafers out of the lock. Therefore, a variation 500 of the lock 410, which does provide a more positive engagement to drive the level change wafers out of the lock, is illustrated in Figures 78-82. The structure and operation of this variation 500 is much the same as the lock embodiment 410 described above and illustrated in Figures 68-77. However, this variation 500 includes two troughs 445, 446 recessed into the peripheral surface of the cylinder 420 and intersecting the respective chambers into which the fifth and sixth service pins 415, 416 are positioned. These recessed troughs 445, 446 are illustrated in Figure 78. The function of these troughs is best shown in Figures 79-82, which are cross-sectional views of the sixth pin position of the lock 500.

Referring first primarily to Figures 78 and 79, this lock embodiment 500 appears in cross-section very similar to that shown in Figure 72 for the previously described lock embodiment 410. However, the recessed trough 446 is shown in alignment with the ejection opening 486. Also like Figure 72, the illustration in Figure 79 shows a key 490 having a B6/5C bit in the sixth position to push the first user level change wafer 471 above the shear line and into alignment with the ejection opening 486.

When the cylinder 420 in lock 500 is rotated clockwise, as indicated by the arrow in Figure 80, the first user level change wafer 471 is forced by the bias of spring 466 downwardly into the trough 446 as soon as it can clear the second user level wafer 472. Then, as shown in Figure 81, when the cylinder 420 is rotated oppositely in the counter-clockwise direction, the edge 479 of the second user 1evel_"wafer 472 engages the first user level wafer 471 and drives it laterally into the ejection opening 486. With continued counter-clockwise rotation of the cylinder as shown in Figure 82, the first user level wafer 471 is successfully ejected through the opening 4₈₆ and out of the lock 500.

The ejection of a master level change wafer 481, 482 with the assistance of the trough 445 is the same in function as just described above for the ejection of the user level change wafer 471. Therefore, further explanation or description of the process of changing the master level keying combination of this embodiment is not deemed necessary. Also, additional user and master level wafers can be ejected from the lock by providing user and master keys of different bitting combinations, as described above for the preferred embodiment illustrated in Figures 4-42. Therefore, it is also not considered necessary to further describe or explain the process of changing additional keying level combinations for this embodiment, which should now be understandable to persons having skill in this art from the description above.

Another variation 501 of the lock embodiments 410 and 500 described above is shown in Figures 83-87. This variation lock 501 is very similar to the embodiment 500 shown in Figures 78-82, with the exception that the recessed troughs 455, 456 in lock embodiment 501 are angularly offset from the pin chambers. However, these troughs 455, 456, which are also recessed into the peripheral surface of the cylinder 420, as shown in Figure 83, also provide positive engagement of the level change wafers to be ejected. This wafer ejection operation in lock 501 will now be described with reference to Figures 84 through 87.

Figure_-B4 is a cross-sectional view of the sixth pin position of lock 501, similar to those shown in Figures 72 and 79 for the respective embodiments 410 and 500 of the lock described above. As shown in Figure 84, the recessed trough 456 is offset an angularly spaced distance from the chamber in the cylinder 420 containing the service pin 416 and the user level change wafers 471, 472, 473, 474. As also illustrated in Figure 84, a key 490 having a B6/5C sixth bit is used to position the first user level change wafer 471 above the shear line 100 and in alignment with the ejection opening 486. When the cylinder 420 is rotated clockwise, as indicated by the arrow in Figur= 85, to a position where the recessed trough 456 is aligned with the driver pin 436, the bias of the spring 466 forces the first user level change wafer 471 downwardly into the recessed trough 456. Then, when the cylinder 420 is oppositely rotated in the counter-clockwise direction, as indicated in Figure 86, the recessed trough 486 carries the first user level change wafer 471 into the opening 486. Continued counter-clockwise rotation of the cylinder 420, as shown in Figure 87, results in successful ejection of the first user level change wafer 471 from the lock 501 to effect a change in the user keying combination of the lock 501.

Again, a change of a master level keying combination is accomplished essentially as described above for a change of a user level wafer, with the exception, of course, that the key bitting must be cut to position the master level change wafer to be ejected above the shear line 100 in alignment with the opening 485, while the user level change wafers are all positioned below the shear line 100 and not in alignment with the ejection opening 486. Such ejection of a master level change wafer according to this invention is described more fully above in reference to Figures 75-77, so it is not believed to be necessary to describe that operation again here.

Another embodiment 510 of a rekeyable multiple level user and master key system according to this invention that can be operated with rotation of the cylinder less than 180⁰ is illustrated in Figures 88-99. Referring primarily to Figures 88 and 89, this lock embodiment 510 has a cylinder 520 with service pins 511, 512, 513, 514, 515, 516 positioned therein. It also includes driver pins 531, 532, 533, 534, 535, 536 biased by springs 561, 562, 563, 564, 565, 566 in a conventional manner. A permanent master wafer 580 is positioned under the driver pin 531 in the first pin chamber. Three user level change wafers 571, 572, 573 are positioned under the driver pin 536, and two master level change wafers 581, 582 are positioned under driver pin 535.

It is significant in this invention that the diameter of the user level change wafers 571, 572, 573, as well as the diameters of the master level change wafers 581, 582 are smaller than the diameters of the correspondingly respective service pins 515, 516 and driver pins 535, 536. Also, positioned between the user level change pin 573 and the service pin 516 is a blocking wafer 574. This blocking wafer 574 is of about the same diameter as the service pin 516 and driver pin 536. Likewise, a blocking wafer 583 is positioned between the master level change wafer 582 and the service pin 515. This blocking wafer 583 is also of approximately the same diameter as the service pin 515 and the driver pin 535.

As best shown in Figure 88, this lock embodiment 510 also includes two spaced apart holes 545, 546 extending transversely into the cylinder 520 at angularly spaced distances from the fifth and sixth pin chambers in the cylinder 520. These holes 545, 546 are positioned such that upon rotation of the cylinder 520, they can be aligned with the level change wafers, as will be described more fully below. They are also deep enough to hold all the level change wafers to be dropped therein, preferably at least two or more of such wafers, according to this invention for multiple level rekeying capabilities.

The first level user key 590 illustrated in Figure 89 is bitted similar to the first level user key described above in the preferred embodiment and illustrated in Figure 4. In other words, it has a B6/9C sixth bit that is effective to position the bottom of the driver pin 536 on the shear line 100 and to position the user level change wafers 571, 572, 573 inside the cylinder 520. The 5B/1C fifth bit is effective to position the top of the service pin 515 at the shear line 100 with the master level change wafers 581, 582 and the blocking wafer 583 above the shear line 100. Thus, the first level user key 590, as shown in Figure 89, works off the shear line at the bottom of driver pin 536 and off the shear line at the top of service pin 515.

In order to rekey the lock 510 to the second user level, the second level user key 591 is positioned in the lock cylinder 520, as shown in Figure 90. Referring now to Figures 90, 91, and 92, the B6/7C sixth bit in this second level user key 591 raises the first user level change wafer 571 above the shear line 100. The remaining user level change wafers 572, 573, as well as the blocking wafer 574 are left in the cylinder 520 below the shear line 100. At the same time, the B5/lC fifth bit on the second level user key 591 positions all of the master level change wafers 581, 582, as well as the blocking wafer 583 above the shear line 100.

Then, as the cylinder 520 is rotated by the second level user key 591, as shown in Figures 93 and 94, the user level change wafer 571, which was positioned above the shear line 100, is pushed by the bias of spring 566 into the hole 546_.where it is captured. Since the hole 546 is smaller in diameter than the driver pin 536, the driver pin 536 cannot enter therein, thus the. rotation of the cylinder 520 is unimpaired.

In the same operation wherein the user level change wafer 571 is captured in the hole 546, the hole 545 also comes into alignment with the master level change wafers 581, 582, as shown in Figure 94. However, since the blocking wafer 583 is larger in diameter than the hole 545, the master level change wafers 581, 582 are effectively blocked out of the hole 545 so that no change in the master level keying is effected by this operatic. The result is that the user level change wafer 571 is permanently captured in the hole 546 to change the user level keying while the master level keying is left unchanged.

When this description is considered in view of the more detailed description above of user level keying changes for the preferred embodiment 10 illustrated in Figures 4-42, it should be now be apparent that additional user level changes in-this lock 510 can also be accomplished by subsequent user level keys that raise sequentially additional user level change wafers 572, 573 above the shear line and then rotating the cylinder 520 to capture the respective level change wafers as desired. Therefore, a further detailed description of such additional user level changes for this lock embodiment 510 should not be necessary. It is significant to mention, however, that the hole 546 is deep enough to also capture and hold the remaining user level change wafers 572, 573.

A change of the master level keying in lock 510 is best described by reference to Figures 95-99. The second level master key 592 having a B6/lC sixth bit'and a B5/5C fifth bit is positioned in the lock 510. As shown in Figures 95 and 96, this second level master key 592 raises the remaining user level change wafers 572, 573, as well as the blocking wafer 574 above the shear line 100. At the same time, as shown in Figures 95 and 97, this second level master key 592 raises the first master level change key 581 above the shear line 100, while leaving the remaining master level change wafer 582 and the blocking wafer 583 in the cylinder 520 below the shear line 100. Then, as illustrated in Figures 98 and 99, when the cylinder 520 is rotated to align the hole 546 with the remaining user level change wafers 572, 573, the larger diameter blocking wafer 574 prevents the user level change wafers 572, 573 from entering the hole 546. Thus, the user level keying is left unchanged. At the same time, however, as shown in Figure 99, the master level change wafer 581 that had been positioned above the shear line 100 is pushed by the bias of spring 565 into the hole 545 where it is permanently captured, thus effecting a change in the master level keying. Again, the larger diameter driver pin 535 cannot enter the hole 545, thus the rotation of the cylinder 520 is left unimpaired.

An additional change in the master level keying can be accomplished by using a third master level key that positions the master level change wafer 582 above the shear line and then rotating the cylinder 520 until that master level change wafer 582 drops into the hole 545.

For purposes of illustration and not of limitation, the driver pins 535, 536 and the service pins 515, 516 of lock 510 can be of a conventional diameter, for example 0.115 inches. The blocking wafers 574 and 583 can also be of the same 0.115 inch diameter as the driver and service pins. The user level change wafers 571, 572, 573, as well as the master level change wafers 581, 582 can be of approximately 0.095 inches. The holes 545, 546 can be approximately 0.100 inches in diameter, which is large enough to capture the level change wafers, but small enough to exclude the blocking wafers and the driver pins. The holes 545, 546 should be of sufficient depth to accept all of the level change wafers desired to be captured for rekeying the lock. For example, where each level change wafer has a two-cut thickness, i.e., approximately 0.030 inches, a hole depth of-approximately 0.095 inches should be sufficient to capture three of such wafers.

From the above descriptions of the various embodiments and modifications of the present invention, it should be understood that each of the rekeyable locks disclosed here can be combined with selected ones or all high security enhancement features disclosed herein. In other words, each of the rekeyable lock embodiments of this invention can be enhanced in security to the extent desired by use of the security enhancing apparatus of this invention.

It should also be understood that positions of user and master level pin wafers can be interchanged with respect to pin chambers, over or under the shear line, or the use of blocking wafers to retain the keying of a user or master system while the keying of the other is being changed. Therefore, many rearrangements of such positions of these components can be made in locks having a number of pin chambers which would be functional and structural equivalents to the particular arrangements described in detail above.

The foregoing description is considered as illustrative only of the principles of the invention to enable persons of ordinary skill in the art to practice the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and processes shown and described. Therefore, the scope of this invention includes all suitable modifications and equivalents that fall within the scope of the invention as defined by the claims which follow.