COMBINATION LOCK

Abstract: In order to simplify the production of a combination lock as many parts as possible are standardized. This applies to the pressure pins (18), the click pawls (16) and the springs (26, 27) belonging thereto, as well as to the pivotal code units (5) which are provided with a cam (9) for impacting on the pressure pins (18) for unlocking the lock. The individual code units (5) comprise a fitting part (7) with eight fitting positions, a cam shaft (8) having a click disc (6) with eight teeth interspaces and a turn button (11) with eight fitting positions. This permits the lock to be coded during fitting in that the choice of angular positions for the base (7) gives the position of the cam (9) and hence the coding of the unit. This means that manufacture as well as fitting and coding of the lock is simplified.

Description: COMBINATION LOCK The invention relates to a combination lock comprising tumblers which can each be displaced in a channel in a release part by means of an adjustable cam so that the release part can be released for motion at a certain cam position, which is different from one tumbler to the other, and thereby permit opening of the lock. Locks of this kind are used wherever there is a demand for a high degree of security in that the number of combi¬ nations can be made very large. This is obtained by a suitable choice of tumblers and corresponding code units. Add to this that the use of a key is avoided which makes the lock much more reliable and strong since there is no direct access to the tumblers which are protected in a strong lock housing. Hitherto known locks of this kind are, however, very com¬ plex and expensive to manufacture. This is particularly due to the many different parts and components which are required and to the complicated constructions of the release mechanism. Each lock unit is thus built of several code units which are more or less different due to their position in relation to each other relative to the release part and hence the' tumblers. It is the object of the invention to overcome these shortcomings and disadvantages of the known combination locks, and this is obtained by a lock where each tumbler consists of a split pin whose end piece has a length which is equal to the length of the channel in the release part, and that the cam is fitted on a pivotal unit in such a man¬ ner that the cam can be pivoted for abutment on the end surface of the pin and thereby move the end piece into the channel for disengagement of the release part. By means of this construction the release part can be embodied as a longish body which can be fitted parallel to the upper surface of the lock housing whereby the indivi- dual pivotal code units can be enclosed and fitted opposite each a tumbler in the release part. This permits a hitherto unobtainable simplification of the used components just as the number of combinations can be made very large merely depending on the number of units and degree of setting. By, as dealt with in claim 2, designing the code unit with a pivotal cam, the lock can be coded when it is fitted by changing the angular position of the cam relative to the tumbler. This simplifies the manufacture of the lock, because the coding and the fitting is performed simul¬ taneously. By, as dealt with in claim 3, fitting the bottom of the code unit in the lock housing by pressing it down over a number of pins which engage with grooves, the unit and hence the angular position of the cam can be chosen freely in connection with the fitting. By, as dealt with in claim 4, unifying the number of click teeth, grooves and button positions, the operation can be made uniform and the coding performed while fitting the lock. As dealt with in claim 5, providing the click pawls and the pressure pins with different spring tensions, enables the position of the cam to be disguised and the friction of the turn buttons to be varied. By, as dealt with in claim 6, providing the release part with teeth which can displace the click pawls as well as the locking pawls, the lock can be disengaged by a single longitudinal impact on the release part. Finally it is expedient, as dealt with in claim 7, to zero- set the individual code units when unlocking the lock in that this automatically cancels the code. In the following the invention will be described with reference to the drawing, in which fig. 1 is a perspective view of the position of each part in the locked position when fitting the lock, fig. 2 is a sectional view of a code unit seen in the direction II-II in fig. 1, fig. 3 is a sectional view of the release arm and the one locking pawl seen in the direction III-III in fig. 1. fig. 4 is a sectional view of the release arm and the other locking pawl seen in the direction IV-IV in fig. 1. fig. 5 is a perspective view of the position of the parts set for unlocking, fig. 6 is a sectional view of a code unit seen in the direction VI-VI in fig. 5, fig. 7 is a perspective view of the position of the parts during unlocking, fig. 8 is a sectional view of a code unit seen in the direction VIII-VIII in fig. 7, fig. 9 is a sectional view of the release arm and the one locking pawl seen in the direction IX-IX in fig. 7, and fig. 10 is a sectional view of the release arm and the other locking pawl seen in the direction X-X in fig. 7. The drawing shows an example of an embodiment of a combination lock as it may be configured for being fitted in a bicycle lock with locking ring or locking arm. However, only those parts are shown as are necessary in or¬ der to understand the invention. Thus, as shown in figs. 1, 5 and 7, there is an oblong release arm 1 which at its one end is provided with a button 3 projecting outside the lock housing (not shown) which button can be pushed in so that the locking arm in the position for unlocking the lock, as shown in fig. 5, can be displaced longitudinally against the spring force of a return spring 4. On one side - the front - the locking arm 1 is provided with a number of channels 17, vide particularly fig. 7, ex¬ tending in the transverse direction of the arm. Moreover, a number of teeth 2 with inclined side faces are formed on the back of the arm 1 against which teeth a number of click pawls 16 and locking pawls 12, 13 rest. As is seen in fig. 7, these pawls 12, 13, 16 are moved away from the back of the locking arm when the button 3 of the locking arm is impacted inwards. Moreover, a pressure pin 18 is inserted in the channel 17, vide particularly figs. 2-4, the said pin being divided into two in such a manner that the length of the outermost portion corresponds to the depth of the channel 17 as shown in fig. 6. These pressure pins 18 are all spring-loaded by implied springs 26, vide figs. 2, 6 and 8, which push the pins 18 out through the channel 17. Likewise, the click pawls 16 are spring-loaded in the same direction by means of implied springs 27, vide figs. 2, 6 and 8, and the locking pawls 12, 13 are impacted on by springs 28 as implied in figs. 3 and 4. As shown in fig. 3 the rear of the one locking pawl 12 is provided with a downwards projecting pawl arm 25 being in engagement with a hole in a pivotally mounted further lock- ing pawl 14, vide part. figs. 1 and 7, so that a movement of the locking pawl 12 causes a pivoting or turning of the locking pawl 14, as shown by the arrow in fig. 7. The lock¬ ing pawl 14 can for example disengage a not-shown fixed locking part. The two locking pawls 12, 13 pointing forwards have different embodiments of their end surfaces for interaction with a bevelled locking groove 23, vide fig. 9 and a straight locking groove 24, see fig. 10, respectively, pro- vided in the locking ring 21 which is disengaged when the locking pawls 12, 13 are carried backwards and out of engagement with the ring 21, as shown in figs. 9 and 10. In the shown example there are four sets of pressure pins 18 but more or less are of course possible if requirements make more or less combinations of the lock necessary. A pivotal unit 5 acting on the pressure pins 18 is on its outside provided with a cam 9 which can be swung towards the pin and push it into the channel 17, as shown in fig. 6. Where the cam 9 is turned away from this position, the tumbler springs 26 will push the pin out towards the cam shaft 8, as shown in figs. 2-4, whereby the pin 18 will bar the longitudinal displacement of the release arm 1. In this condition the lock will be locked. In order to be able to operate the lock by means of the cam 9 the pivotal part 5 is constructed, as shown in figs. 2, 6 and 8, with a base 7 being provided with a number of fitting grooves 10 in which assembly pins 22 can be insert¬ ed. In the shown example there are eight grooves 10 evenly distributed along the periphery of the base 7. The base is moreover provided with a central upwards extending pin about which the cam shaft 8 can turn. In order for the cam shaft 8 in connection with the unlock- ing to swing back to its initial position, as shown in fig. 1, there is built in a return spring between the shaft 8 and the base 7. Apart from the cam 9, the shaft 8 is further provided with a click disc 6 with eight teeth. As will be seen from figs. 1 and 5, a spring force 27 causes the click pawl 16 to en¬ gage with the spaces between the teeth on the click disc. In the click disc 6 there is finally a centre hole 29 which is octagonal and into which an octagonal pin on the bottom surface of a turn button can be pressed. In figs. 1, 5 and 7 a dark triangle on top of the click disc 6 implies the position of the cam 9 in relation to the pressure pin 18. In the initial position shown in fig. 1 the lock is coded so that each button 11 must be turned a different number of clicks in order to bring the cams 9 in the required positions for unlocking, where each cam pushes the pressure pin inwards to flush with the front edge of the arm 1, as shown in figs. 5 and 6. In this position the button 3 of the release arm 1 can be pushed in, whereby those motions take place as are shown by arrows in fig. 7. The release arm 1 is moved lengthwise, whereby the slide faces on the teeth 2 move the click pawls 16 back thereby disengaging the cam shaft 8 which are turn¬ ed back to their initial position by the springs in the base 7. Moreover, both locking pawls 12, 13 are moved back- wards, and the locking pawl 14 turns itself from engagement with the blocking parts or ring 21 which make up the lock¬ ing element. When the arm 1 is then returned by the spring 4, the springs 26, 27, 28 will push the mentioned moving parts back to their initial position, as shown in fig. 1. Having eight fitting grooves 10 on the base 7, eight teeth spaces on the click disc 6 and eight edges on the hole 29 for the button 11 serves to provide the opportunity of coding the individual units 5 during the actual fitting of the lock. The pivotal code units 5 are all identical, and coding of each unit takes place during the actual fitting in the lock housing 19, 20. As shown by black triangles in fig. 1, each unit is differently orientated prior to being pressed into place in assembly pins 22. As implied at the top of fig. 5, each button 11 must hereby be turned a different number of clicks in order to unlock the lock, viz. one, three, four and six clicks, respectively, in the shown example. In order to disguise the position of the cams, the tumbler springs 26 and click pawl springs 27 may have different spring tensions which makes it impossible to determine the position of the cams 9. It will be an advantage to apply identical springs which, when fitted in holes or bores of varying lengths, will provide the required variation. As will appear from the specification and drawing, mainly identical components are used. Thus, the code units 5 are identical as are the pressure pins 18, the click pawls 16 and the springs 26, 27. This makes production less ex¬ pensive and enables an automated fitting of the lock. Moreover, coding can be varied by the choice between - in the shown example - eight different positions for one unit. In the shown example only such a locking arm is described and shown as can be moved in longitudinal direction, but it also lies within the scope of the invention to configure the arm as a pivotal cylinder which is turned by locking thereby disengaging the locking pawls.

Claims: C L A I M S 1. Combination lock comprising tumblers which can each be displaced in a channel in a release part by means of an adjustable cam so that the release part can be released for motion at a certain cam position, which varies from one tumbler to the other, and thereby permit opening of the lock, c h a r a c t e r i z e d in that each tumbler con¬ sists of a split pin whose end piece (18) has a length which is equal to the length of the channel (17) in the re¬ lease part (1), and in that the cam (9) is fitted on a pivotal unit (5) in such a manner that the cam (9) can be pivoted for abutment on the end surface of the pin (18) and thereby move the end piece (18) into the channel (17) for disengagement of the release part (1). 2. Combination lock according to claim 1, c h a r a c ¬ t e r i z e d in that the pivotal unit (5) comprises a lower stationary part (7) and a shaft (8) mounted thereto, the said shaft (8) on the outside being provided with the cam (9) and a number of teeth (6) between which a pawl (16) can be inserted, and moreover is provided with a button (11) on top of the shaft (8). 3. Combination lock according to claim 2, c h a r a c ¬ t e r i z e d in that the stationary part (7) is provided with a number of fitting grooves (10) in which pins (22) can be pressed in for securing the pivotal unit (5), and in that the button (11) on its underside is provided with a multi-edged pin which can be inserted into a corresponding multi-edged hole (29) in the end face of the shaft (8). 4. Combination lock according to claims 2 and 3, c h a ¬ r a c t e r i z e d in that the number of teeth (6), fitting grooves (10) and hole edges (29) is equal and has the same distance to each other. 5. Combination lock according to claims 2-4, c h a r a c ¬ t e r i z e d in that the pawl (16) and the pressure pin (18) are impacted on by a spring (27, 26) by a force which may be different from unit to unit (5). 6. Combination lock according to claims 1-5, c h a r a c ¬ t e r i z e d in that the release part (1) is provided with a number of teeth (2) which, when the release part is released for motion partly displace the pawls (16) from en- gagement with the teeth (6) and partly displace one or more locking pawls (12, 13) from engagement with the locking element(s) (21). 7. Combination lock according to claims 2-6, c h a r a c - t e r i z e d in that the shaft (8) is provided with a spring which returns the shaft to its initial position in the stationary part (7) when the pawl (16) is displaced from engagement with the teeth (6).

Inventors: DUNCH POUL, DUNCH, POUL
Applicants: BASTA LAASEFAB AS, BASTA LAASEFABRIK A/S
Application year: 1990
Main classification: E05B71
IPC codes: E05B37