Key controlled lock having built-in switch actuator operated by insertion and removal of key

July 14, 1970 e. n. jacobi 3,520,161

KEY CONTROLLED LOCK HAVING BUILT-IN SWITCH ACTUATOR OPERATED BY INSERTION AND REMOVAL OF KEY

Filed July 17, 1368 2 Sheets-Stieet ’

<img file="US3520161A_D0001.tif" />

July 14, 1970 e. n. jacobi

KEY CONTROLLED LOCK HAVING BUILT-IN SWITCH OPERATED BY INSERTION AND REMOVAL OF Filed July 17. 1968

3,520,161

ACTUATOR

KEY

Sheets-Sheet ::

<img file="US3520161A_D0002.tif" />

Edward Jacobi

3,520,161

Patented July 14, 1970

United States Patent Office

3,520,161

KEY CONTROLLED LOCK HAVING BUILT-IN SWITCH ACTUATOR OPERATED BY INSERTION AND REMOVAL OF KEY

Edward N. Jacobi, Milwaukee, Wis., assignor to Briggs g &amp; Stratton Corporation, Milwaukee, Wis., a corporation of Delaware

Filed July 17, 1968, Ser. No. 745,639

Int. Cl. E05b 35/14

U.S. CI. 70—387 5 Claims

ABSTRACT OF THE DISCLOSURE

A key controlled tumbler lock with a cylinder rotatable in a bored lock casing, has a switch actuating lever jg pivotally mounted in a longitudinally extending slot in the wall of the lock case. The free end of the lever is projected beyond the cylindrical boundary surface of the lock case by the engagement of the straight back edge of the key with a finger on the lever as the key 20 is inserted into the keyway of the cylinder, and is retracted by a spring when the key is withdrawn, at which time the finger on the lever enters the keyway.

This invention relates to locks and refers more particularly to ignition switch locks for automobiles.

SUMMARY

The invention is concerned with the problem of re- 30 ducing automobile thefts resulting from the driver’s failure to remove the igntion key from the ignition switch lock. It deals with the problem by effecting closure of a buzzer energizing circuit by the opening of the door on the driver’s side of the automobile in the event the 35 the ignition key is left in the keyway of the lock. Ignition switch locks having this capability are presently standard equipment in the cars of at least one large automobile manufacturer, but in those cars, the warning buzzer circuit can be disabled by simply withdrawing 40 the key a slight amount—not more than about one-eighth of an inch either before or after the door is opened. Needless, to say, this can lead to a habit which defeats the entire purpose of the warning system.

With this invention, the lock controlled switch in the 45 warning buzzer circuit is closed as long the key remains in the lock far enough to keep from falling out. Only upon complete removal of the key does the lock controlled switch open.

The invention achieves its objective by providing the 50 lock with a switch actuator located in an aperture in the side of the lock case, and yieldingly biased to a retracted position in which a finger on the actuator projects into the keyway of the cylinder when the cylinder is in its locked position of rotation and no key is pres- ⁵⁵ent therein. In this retracted position, no part of the actuator protrudes beyond the cylindrical boundary surface of the lock case. But, upon insertion of the key, the finger on the actuator is expelled from the keyway and another part thereof is projected beyond the side ⁶⁰of the lock case. The movement of the actuator between its retracted and projected positions is utilized to open and close a switch in the warning buzzer circuit.

The purpose and object of the invention, thus is to provide an improved key controlled lock having a builtin switch actuator which is movable between a retracted position in which no part thereof protrudes beyond the side of the lock case and a projected position in which a switch actuated part thereof does protrude beyond the side of the lock case; and wherein the actuator occupies its projected position whenever a key is in the lock and until the key is fully removed.

The only prior art known that comes close to disclosing a lock having the aforesaid capabilities is the Fitzgerald Pat. No. 2,105,350.

With these observations and objects in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings. This disclosure is intended merely to exemplify the invention.

The drawings illustrate one complete example of the physical embodiments of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is essentially a longitudinal sectional view through a key controlled lock embodying this invention, said view illustrating the situation which obtains when no key is present in the lock;

FIG. 2 is a view similar to FIG. 1, but with a key in the keyway;

FIG. 3 is a cross-sectional view through FIG. 1 on the plane of the line 3—3;

FIG. 4 is a cross sectional view through FIG. 2 on the plane of the line 4—4; and

FIG. 5 is an exploded perspective view of the parts of the lock primarily involved with this invention.

Referring to the drawings, the numeral 6 designates generally a key controlled pin tumbler lock of the type commonly used to control automobile ignition switches. As is customary, the lock comprises a casing 7 having a bore 8 in which a lock cylinder 9 is rotatably received. The cylinder is secured against rotation by a group of pin tumblers and drivers, collectively designated by the numeral 10, until insertion of a proper key 11 into the key way 12 of the lock cylinder. Insertion of the key frees the cylinder for rotation and enables switch actuating motion to be imparted to the contactor of the ignition switch (not shown) through a driver 13 which projects from the rear or inner end of the cylinder.

Since the purpose of the invention is to control an electric circuit as—for instance—the energizing circuit of a warning buzzer by the presence or absence of the key in the lock, the lock case 7 has a switch actuator 14 mounted therein for movement between a retracted position shown in FIG. 1 and a projected position shown in FIG. 1 and a projected position shown in FIG. 2. Movement of the actuator 14 from one to the other of these positions, is utilized to actuate a micro-switch 15 mounted in juxaposition to the lock. In a customary installation, the switch 15 and adoor controlled switch in series circuit therewith (not shown) controls energization of a warning buzzer, the sounding of which indicates that the key has not been removed from the lock.

The actuator 14 is a flat sided lever—preferably stamped from sheet metal. It is received in a longitudinally extending slot 17 which is open throughout its length to the cylindrical boundary surface of the lock case and communicates with the bore 8 through a hole

3,520,161 ³

18. The actuator lever is pivotally assembled with the lock case by the insertion of an embossure 19 protruding from one side of the lever into a recess or cavity 20 in the adjacent side of the slot 17. The recess or cavity 20 opens to the front end of the lock case, and the embossure is retained in the recess 20 by the attachment of an escutcheon cap 21 to the front end of the lock.

Preferably, a hardened steel apertured disc 22 is interposed between the front end of the lock case and the escutcheon cap to provide protection against drilling into the lock. The inner surface of this hardened steel disc closes the open mouth of the recess 20 and thus confines the actuator lever 14 in position.

A finger 23 on the actuator lever projects through the hole 18 and into the keyway 12 of the lock cylinder when the cylinder is in its locked position of rotation, and no key is present in the keyway. This relationship of the parts (illustrated in FIGS. 1 and 3) is yieldingly maintained by a spring 24 confined between the finger 23 and the opposite wall 25 of a recess 26 formed in the lock case and opening to said slot 17 and also the hole 18.

The spring produced rocking movement of the actuator lever 14 is limited by the engagement of its free end with a surface 27 which constitutes the bottom of the adjacent portion of the slot 17. In this spring retracted position of the actuating lever, no part thereof projects out of the mouth of the slot 17 or protrudes beyond the cylindrical surface boundary of the lock case.

Upon insertion of the key, however, the finger 23 is expelled from the keyway and, as a result, the actuator lever 14 is rocked about its pivot 19 to project the outer free end of the lever beyond the cylindrical boundary surface of the lock case and, in so doing, depress the driver or contact controlling member of the microswitch 15, as shown in FIG. 2.

Since the keyway 12 opens to the cylindrical boundary surface of the cylinder, at least along that portion of the length of the keyway which encompasses the group of pin tumblers and drivers, and since the back edge 30 of the key is flush with the cylindrical boundary of the lock cylinder, it follows that the actuator undergoes no change in position from that shown in FIG. 2 when the cylinder is turned by means of the key. Also, since the finger 23 is located close to the pivot 19 for the actuator lever, and opposite the front end of the group of pin tumblers and drivers, it follows that the actuator lever 14 will occupy its projected position as long as the key remains far enough in the keyway to prevent its falling out. This will be evident from the dotted line illustration DL of the nose of the key in FIG. 2.

It will be noted that the outer edge of the actuator lever 14 is so shaped that, even in its projected position, substantially only its free end portion 31 protrudes beyond the cylindrical boundary surface of the lock case. This relationship enables the lock to be mounted in the conventional way, which requires that a substantial part of the length of the lock case be received in a relatively close fitting round hole in the supporting structure in which the lock is mounted.

From the foregoing description taken in connection with the accompanying drawings, it will be apparent to those skilled in this art that this invention provides a significantly improved ignition lock for automobiles in which the presence of absence of the key is utilized to control the energizing circuit of a warning buzzer.

Those skilled in the art will also appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims.