A programmable cylinder lock having a high number of combinations

The present invention relates to a programmable cylinder lock, namely a lock comprising devices intended to enable pre-coding of the lock or, by means of a change operation, to modify the last coding of the lock in order to adapt the lock to be operated with a key other than the key to which the lock was originally adapted.

[0002] More specifically, the invention relates to improvements to a programmable cylinder lock of the type that is known from European Patents No. 0 226 252 and No. 0 900 310. [0003] In an ordinary cylinder lock that includes a fixed part and a cylindrical rotary part mounted inside the fixed part for rotation about its own axis, having a keyhole extending towards the axis for inserting the key, a number of pins are mounted inside the rotary part locking, moving perpendicular to the axis at the extension of the keyhole plane, and each locking pin is designed to work with a key segment, whose coding is represented by the level of the tooth or key cavity located inside the segment in question. The fixed length of each locking pin is such that when it interacts with the corresponding segment of the correct key, the distal end of the locking pin corresponds to the cylindrical surface of the rotating part and does not impede its rotational movement, as a result of which when all the locking pins move into the appropriate correct positions by means of the correct key, the rotating part can rotate to operate the lock. If, otherwise, one or more locking pins are in the wrong positions, they extend (or the corresponding counter-locks that can be used in the fixed part) across the cylindrical surface of the rotating part and stop its rotational movement and thus the operation of the lock . Because the coding of the lock is represented by a fixed length of locking pins, which is determined at the production stage, the lock can be operated with only one proper key and cannot be programmed differently.

[0004] Programmable cylinder locks of the type considered in the present invention and described in said patents comprise in a rotatable part which is pivotally mounted inside the fixed part, instead of locking pins of a predetermined length, a number of key-driven elements movable along their own longitudinal and transverse direction . wherein said key driven elements are intended to cooperate with the coding arrangements of the key inserted in the keyhole of the rotating part, and the corresponding number of locking pins movable along their own longitudinal direction, which form the locking elements of the lock. The key-driven components and locking pins together form a number of pairs, each of which includes a key-driven component and locking pins, and are provided with teeth for mutual cooperation in various relative positions to determine the coding of the lock. The limiting rod that is laterally movable, cooperating with the longitudinal groove of the fixed part and having the projections having the possibility of cooperating with the notches of the locking pins, is intended to immobilize the locking pins when the rotating part is set into rotational movement inside the fixed part and, as a result, the limiting rod comes out of said groove and engages with locking pins. The shift rod, which is laterally displaceable and is slidably coupled to the key driven elements, normally keeps the key driven elements engaged with the locking pins, but when said shift rod enters the said groove of the fixed part, it laterally displaces the key driven elements and detaches them from the pins locking, thus allowing modification of the coding of the lock by replacing the last key with another key.

[0005] In a lock of this type it is required that the number of possible coding combinations, namely the number of different keys provided for different locks of the same type, be as high as possible. One of the parameters determining the number of possible combinations is the number of coding levels that can be predicted for the key segments, and this number depends on the pitch of the mating teeth of each pair of key driven elements and the locking pins. The smaller this scale is, the greater the number of possible encodings. However, the pitch of these toothing cannot be reduced below certain limit values ​​because, on the one hand, this would pose greater manufacturing difficulties, and on the other, because the coupling between pairs of key driven elements and locking pins will no longer have sufficient mechanical strength.

SUMMARY OF THE INVENTION [0006] The main object of the present invention is to improve the lock of the type in question to compensate for the disadvantage found by allowing an increase in the number of possible coding levels, without resorting to reducing the pitch of the cooperating teeth of key-driven elements and locking pins.

[0007] In a lock of the type in question, this object is achieved according to the invention in that one of the two elements that form at least several pairs, each containing a locking pin and a key driven element, is provided with two parallel and adjacent toothing, each tooth having its pitch shifted in relation to the pitch of the second teeth, and by the fact that at least one of the mentioned elements, which form a pair comprising a locking pin and a key driven element also have limited mobility along the direction of the axis of the rotating part, whereby said element can move in such a way that mutual engagement between the two elements can take place with one or the other of said two teeth of one from the elements forming a pair.

[0008] Thanks to this arrangement, the number of relative positions in which the locking pins and key-driven elements forming a pair can engage is doubled because in each case one or the other toothing can be used whose pitch is not in phase. In this way, without reducing the tooth pitch, a number of coding combinations are obtained that corresponds to the number of coding combinations that can be obtained by halving the tooth pitch. It follows that the number of different keys that can be provided is increased without reducing both the ease of manufacture and the mechanical strength of the lock.

[0009] Preferably, said two toothing, locking pin or key-driven member that together form a pair are mutually offset by half a pitch. In this way, an even difference between levels is obtained, which can be ensured by the alternative use of two teeth.

[0010] Preferably, the element of each pair comprising the locking pin and the key-driven elements that has two toothing is the locking pin, whereas the corresponding key-driven element has a single toothing.

[0011] Preferably, both elements of each pair comprising the locking pin and the key-driven element have limited mobility along the axis direction of the rotating part. It is advantageous that the teeth of the teeth of one of the elements forming each pair comprising the locking pin and the key-driven element are provided with a chamfer intended to make the relative displacement of the elements for mutual engagement with the respective teeth to be more simple.

[0013] In this case, said bevel of the teeth can be provided both for the teeth of the key-driven elements and for the locking pins.

[0014] The various features set out are intended to provide a maximally easy engagement between the teeth of the pairs of locking pins and key driven elements.

It is advantageous that the key-driven elements are provided, in the area in which they are slidably coupled to the shift rod, with an extension by which they are forcedly hooked onto the shift rod. In this way it is prevented that the key-driven elements may accidentally take on an abnormal position that may impair the good operation of the lock.

BRIEF DESCRIPTION OF THE DRAWINGS [0016] These and other features, objects and advantages of the subject of the present invention will be more clearly apparent from the following description of the embodiment, which is a non-limiting example, with reference to the accompanying drawings, where:

figure 1 shows, for reference, a cross-section of a programmable cylinder lock known from European Patent No. 0 900 310, in a normal operating condition.

figure 2 shows a cross section corresponding to the section in figure 1, but in a state of change.

figure 3 is a perspective view of the locking pin of the lock according to the invention which is provided with two toothing or not in phase. figure 4 is a perspective view of the key driven element of the lock according to the invention.

figure 5 is a perspective view of the locking pin according to figure 3 and the key-driven element according to figure 4, relatively engaged. figure 6 is a perspective view of a part of the rotating part and key segment, with the pair comprising the locking pin and the key-driven element relatively engaged in the first condition.

figure 7 is a top view of the components shown in figure 6. figure 8 is a perspective view of a part of the rotating part and key segment, with the pair comprising the locking pin and the key-driven element relatively coupled, in a second condition.

figure 9 is a top view of the components shown in figure 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0017] First, reference will be made to figures 1 and 2 in order to recall the overall structure and operation of the lock of the type in question, for which reference is made to the cited details documents. The number 1 denotes the fixed part, inside of which the rotary part 2 is rotatably mounted, having the possibility of receiving the key 3 in its keyhole. Inside the rotary part 2 a number of key-driven elements 4 are mounted, lying in a plane perpendicular to the axis of the rotary part 2 and being movable along their own longitudinal and transverse directions. Key driven elements 4 are designed to work with key 3 coding configurations. In addition, a corresponding number of locking pins 6 is mounted inside the rotating part 2, each locking pin being flush with one of the key driven elements 4 and movable along its own longitudinal direction. In the presented case, the locking pins 6 cooperate with the counter-pins 8 and together form the locking elements of the lock. The key-driven elements 4 have teeth 5, the locking pins have teeth 7, and these teeth are intended for mutual cooperation. This cooperation may take place in various relative positions to determine the coding of the lock. The stop bar 9 is able to move in the transverse direction inside the rotating part 2. has the ability to cooperate with the longitudinal groove 10 of the fixed part 1, has projections intended to cooperate with the recesses of the locking pins 6 and is used to immobilize the locking pins 6 when the rotary part 2 is set into rotational movement inside the fixed part 1, and as a result the limiting rod 9 comes out of said groove 10 and engages with the locking pins 6. The shift rod 11, which can be laterally displaced in the rotating portion 2, is slidably coupled to the key driven elements 4, and normally the shift rod 11 maintains the key driven elements 4 engaged with the locking pins 6, as shown in figure 1, but when said shift rod 11 due to the rotational movement of the rotary part 2 will cover with said groove 10 of the fixed part 1 and enter it, laterally displaces the key-driven elements 4 and detaches them from the locking pins 6, as shown in figure 2. Then, by replacing the last key 3 with another key, it is possible to modify the coding of the lock.

[0018] As can be seen, the tooth pitch 5 and 7, which determines the possible positions for coding the lock, is not very small and cannot be arbitrarily reduced, since this reduction would entail some manufacturing difficulties and weaken the connection between key driven elements and pins locking. This fact limits the possibility of increasing the number of possible coding positions, and thus the number of different keys that can be used for this type of lock.

[0019] As already indicated, according to the invention, one of the two components of at least several of the pairs comprising the locking pin and the key driven element, preferably the locking pin, is provided with two parallel adjacent teeth, each of these teeth having an offset pitch in phase relative to the pitch of the second dentition. This feature results in particular from figure 3. As can be seen, the locking pin 6, for the other generally compatible known shapes, instead of having a single toothing 7, has two parallel, adjacent teeth 7a and 7b, and the pitch of these two teeth are mutually offset in phase. In the example shown, the phase shift is half scale, and this is a favorable condition.

[0020] The key driven element 4 shown in figure 4 normally has a single toothing 5. According to the position of the key driven element 4 relative to the locking pin 6, the toothing 5 is able to engage with the toothing 7a or toothing 7b of the locking pin. For example, according to figure 5, the toothing 5 of the key-driven element 4 engages with the toothing 7b of the locking pin 6. Because the two teeth 7a and 7b are mutually offset by half a pitch, it follows that the possible relative positions of the key-driven element 4 and the locking pin 6 do not differ by the tooth pitch as usual, but only by half the pitch. Thus, with all other conditions being the same and without any reduction in the tooth pitch, the number of possible relative positions of each key-driven element relative to its corresponding locking pin is doubled. The result is a very large increase in the number of possible combinations of lock codings and the corresponding key. [0021] In order that the key-driven elements 4, when they approach the corresponding locking pins 6 when programming the lock, can engage with one or the other toothing 7a and 7b as desired, relative displacement between the key-driven elements 4 and locking pins 6 towards the axis of the rotating part 2. Accordingly, according to the invention, it is required that at least one of said two elements, the key-driven element 4 and the locking pin 6, forming each pair, have limited mobility along the direction of the axis of the rotating part, as a result of which it can move in such a way that the mutual engagement of the two elements takes place, as the case requires, with one or the other of said two teeth of one of the components involved. This mobility can be attributed to key-driven elements 4 or to locking bolts 6, but it is preferred that this mobility is attributed to both of these components, so that its extension can be appropriately reduced.

[0022] If this is considered advantageous, said displacement (which, however, takes place spontaneously) can be facilitated by a slight bevel of the teeth of some teeth of one or the other, or both. This bevel is indicated by 5a in figure 4 for the teeth of the key-driven element 4.

[0023] In the example shown and discussed, the double toothing 7a, 7b has been assigned to the locking pins 6, while the key-driven elements 4 have a single toothing 5. However, it should be noted that the same behavior can be obtained by placing the double toothing on the keyed and single-driven elements teeth on locking pins. The choice between these two possibilities can be imposed by design preferences or by manufacturing recommendations.

[0024] A further explanation of the behavior of the characteristic components of the invention is given in Figures 6 to 9, it being presumed that limited displacement along the axis direction of the rotating part 2 is enabled for both the key-driven elements 4 and the locking pins 6. Figures 6 and 7 refer to the case in which the key driven element 4 is engaged with the toothing 7b of the locking pin 6, while Figures 8 and 9 refer to the case in which the key driven element 4 is engaged with the toothing 7a of the locking pin 6. Of course, one or the other of these cases is due to the fact that in the position where the key 3 brought the key-driven element 4, the tooth pitch 5 of the key-driven element 4 corresponds to the pitch of either one or the other teeth 7a and 7b of the locking pin 6 .

[0025] In the case of figures 6 and 7, the key-driven element 4 moves along the direction of the axis of the rotating part 2 with the arrow F1, while at the same time the locking pin 6 moves towards the axis of the rotating part 2 with the opposite turn, according to arrow F2, whereby the toothing 5 of the key-driven element 4 coincides with the toothing 7b of the locking pin 6 and can engage with it.

Otherwise, in the case of Figures 8 and 9, the key-driven element 4 moves along the direction of the axis of the rotating part 2 with the arrow F3, while at the same time the locking pin 6 moves towards the axis of the rotating part 2 with the return opposite, according to arrow F4, whereby the toothing 5 of the key-driven element 4 coincides with the toothing 7a of the locking pin 6 and can engage with it.

[0027] It should be noted that in the two cases shown, the phrases of the two arrows F1 and F3, according to which the key-driven element 4 moves, are opposite in the two cases shown, and in the same two cases the opposite turns of the two arrows F2 and F4 , according to which the locking pin 6 moves.

[0028] It is preferred that the key-driven elements 4, as can be seen in figures 4 and 5, have an extension 4a in the area in which they are slidably coupled to the shift rod 11. By means of the extension 4a, the key-driven elements 4 are hooked in forced method with a shift rod 11. This prevents the possibility of accidental adoption by key-driven elements, due to their mobility, of an abnormal position that may impair the good operation of the lock.

By using the invention, it becomes possible to greatly increase the number of possible code combinations of the lock, and thus the possible number of different keys, without resorting to a reduction in the tooth pitch of the components, and thus without causing particular manufacturing problems or any weakening of the components.

[0030] All the features described apply to all pairs comprising the key-driven element and the locking pin of the lock or even, for reasons of simplification, only to some pairs, by accepting in this case the reduction of the scope of benefits offered by the invention.

[0031] The features of the invention may apply to locks of the type described, regardless of whether they are provided with master keys or not.

[0032] It is understood that the present invention is not limited to the embodiment described and exemplified. During the description, several possible modifications were pointed out, while others are within the capabilities of specialists in this field. These and other modifications, and all substitutions by technically equivalent means, may be made to what has been described and demonstrated without departing from the spirit of the invention and the scope of this Patent as defined by the appended Claims.