EP0011424B1

EP0011424B1 - Locks

Info

Publication number: EP0011424B1
Application number: EP79302431A
Authority: EP
Inventors: George William Dyson; Kenneth Edwin Taylor
Original assignee: Chubb and Sons Lock and Safe Co Ltd
Current assignee: Gunnebo UK Ltd
Priority date: 1978-11-06
Filing date: 1979-11-02
Publication date: 1983-05-04
Also published as: AU529533B2; NZ191919A; AU5232979A; ZA795692B; DE2965323D1; EP0011424A1

Description

This invention relates to locks of the kind in which linear movement of a slide or runner that is coupled to the bolt of the lock is communicated via the coupling to extend or withdraw the bolt, according respectively to the direction of runner movement, transversely of the line of movement of the runner.
A lock of the above-specified kind is known from German Auslegeschrift No 1,553,441 in which a slide that is engaged by teeth of the inserted key moves upwardly in response to turning of the key in the direction to extend the bolt. The line of movement of the slide is at right angles to that of the bolt, and beneath it, the slide and bolt being intercoupled through a pivotted crank that engages by a pin with a slot in the slide and by another pin with a slot in the bolt. The crank turns as the slide moves upwardly to urge the bolt outwardly from the casing of the lock.
If with the known form of lock, attempt is made to force the bolt back from its extended position this will act via the crank coupling to urge the slide downwardly. Any provision for resisting this in order to deadlock the bolt, will cause the forcing load to be borne by the coupling, and in particular by the comparatively- weak pins that engage the slide and bolt. There is therefore the disadvantage that the known form of lock is likely to have a low resistance to forcing.
According to the present invention a lock of the kind specified is characterised in that a part carried with the runner is moved into the withdrawal path of the bolt, so as to block withdrawal of the bolt, under movement of the runner in the direction for extending the bolt, and that said coupling between the runner and bolt provides lost motion between them such that movement of the runner in the direction for withdrawal of the bolt is communicated to the bolt via the coupling only after the runner has moved sufficiently to clear said part from the withdrawal-path of the bolt.
Movement of the part carried with the runner into the withdrawal-path of the bolt so as thereby to block withdrawal of the extended bolt, is of especial advantage for deadlocking the bolt and securing it against forcing. The forcing load can be borne directly by the obstructing runner-part without significant loading of the coupling. Furthermore the runner-part may be located to be abutted directly by the bolt, and thereby ensure an immediate and solid block to backward movement of the bolt under forcing, since the lost motion provided by the coupling enables the runner to be readily cleared from the bolt when withdrawal is required under normal operation of the lock. The use of the lost-motion coupling also facilitates the correct and close location of the runner part in obstruction to the bolt, during movement of the runner in the direction to extend the bolt.
A form of door lock which also utilizes a slide or runner that is moveable at right angles to the line of movement of the bolt into a position in which it blocks withdrawal of the bolt, is known from French Patent Specification No. 1,573,025. However in this case there is no coupling between the slide and the bolt, the bolt being extended under the action of a spring only when a spring-urged cam is released in response to closing of the door. The bolt can be withdrawn against its spring whenever the door is to be opened except in the circumstances in which the slide has been moved into the withdrawal path of the bolt by turning of a key. This known form of lock is accordingly more in the nature of a lockable latch in which the bolt is extended automatically and in which the problem with which the present invention is especially concerned, namely of relieving forcing load from the coupling between the runner and bolt of a runner-driven lock, does not arise.
A key-operable lock in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows the lock in front elevation with its coverplate removed and bolt extended;
Figure 5 shows the inside face of the cover- plate of the lock;
Figure 3 is a rear elevation of the lock with its bolt extended;
Figure 4 is a part-sectional elevation of the lock, corresponding to Figure 1 and showing more clearly its bolt and runner mechanism;
Figure 5 is a view from the rear of a barrel-and-curtain element that forms part of the lock;
Figures 6 and 7 are part-sectional elevations of the lock, corresponding to Figure 4 and illustrating successive stages in operation of the lock mechanism during withdrawal and extension of the bolt; and
Figure 8 is an enlarged view of part of the lock mechanism, illustrating a safety feature of the lock.

Referring to Figures 1 to 4, the locking bolt 1 when fully extended to its outward, locked position (shown in Figures 1, 3 and 4) protrudes from the lock casing 2 through a rectangular aperture 3 in the forend 4 of the lock. A peg 5 carried on the bolt 1 within the casing 2 engages in an elongate recess 6 (Figure 2) in the cover-plate 7 of the casing 2 for guiding, and also possibly limiting, sliding back and forth through the aperture 3 in withdrawal and extension of the bolt 1. Movements of the bolt 1 are effected by an appropriately-stepped key (not shown) inserted into a key-hole 8 that is open from both sides of the lock through the cover-plate 7 and casing 2 respectively. The inserted key engages a thrower rib 9 (Figure 5) on the underside of a barrel-and-curtain element 10. A leaf spring 11 engages a notch 12 of element 10 to detain the rib 9 normally aligned with the key-hole 8.
Turning of the inserted key in either direction rotates the element 10 so as to disengage the notch 12 from the spring 11 and bring the steps of the key-bit into engagement with a stack of five (there may be more, or fewer) spring-biased levers 13 (Figure 1). The levers 13, which are resiliently biased by individual springs 14, are stacked one upon the other on a pivot pin 15 that projects through a slot 16 (Figure 4) in a slide or runner 17. A stump 18 of the runner 17 is detained within one or the other of two racking slots 19 and 20 of each lever 13 in the stack, being detained in the slot 19 when the bolt 1 is in its outward, locked position, and in the slot 20 when the bolt 1 is in its inward, unlocked position. The stump 18 when so detained precludes movement of the runner 17 until the levers 13 are lifted appropriately against the action of their springs 14, by the turning key. However, unless the key-bit is appropriately stepped, at least one of the levers 13 will not be lifted the individually-required amount to bring its gating aperture 21 (interconnecting the slots 19 and 20) into alignment with the stump 18, and movement of the runner 17 will accordingly continue to be precluded. With the correct key, on the other hand, all levers 13 are lifted just enough to align their gating apertures 21 with the stump 18 so as to free the runner 17 for sliding longitudinally. Such sliding takes place under the influence of the thrower rib 9 as this is turned by the key against a talon 22 (identified in Figure 4) formed in the runner 17. The sliding movement of the runner 17 is communicated to the bolt 1 so as to withdraw or extend it-in dependence upon the direction in which the key is turned.
The bolt 1 is withdrawn from its outward, locked position by turning the key in the clockwise sense with respect to Figure 1. The action of the thrower-rib 9 on the talon 22 in this case slides the runner 17 in the direction to move the stump 18 out of the slot 19 into the slot 20 through the gating aperture 21 of each lifted lever 13. Continued turning of the key to return the rib 9 to alignment with the key-hole 8 and allow withdrawal of the key, releases the levers 13 causing them to spring back to detain the stump 18 in the racking slots 20 and so restrain return movement of the runner 17. Return movement of the runner 17 required to extend the bolt 1 to its outward, locked position, is achieved by turning the key in the opposite, anti-clockwise sense. This lifts levers 13 and again enables the stump 18 to pass through the gating aperture 21 of each lever 13 - in this case from the slot 20 back into the slot 19 - to restore the lock to the condition illustrated in Figure 1.
To the extent that the lock has so far been described in general terms, it is of conventional construction and operation. However in conventional practice the bolt and runner slide along parallel path whereas in the present case the paths are transverse, or more particularly at right angles, to one another. This has significant advantage in that it enables the depth of the lock to be reduced. But it also allows the bolt to be deadlocked by the runner itself in a very secure way that does not rely on the strength of the stump, the levers or the lever pivot, and is better able to resist forcing without damage to the lock. The features of the lock that enable realization of these and other advantages will now be described.
Referring again especially to Figures 1 and 4, the stack of levers 13 is located to one side of the key-hole 8 so that the runner 17 slides upwardly when the correct key is turned clockwise and downwardly when the key is turned anti-clockwise. The upward-downward sliding movement of the runner 17 is communicated to the bolt 1 via a bell-crank element 23 that is pivotted by a pin 24 which engages a hole 25 (Figure 2) in the cover-plate 7, and which extends via a slot 26 in the runner 17 to engage a corresponding hole 27 (Figure 3) in the casing 2. Two pegs 28 and 29 on the element 23 engage with the runner 17 and bolt 1 respectively, the peg 28 being retained within a notch 30 in the runner 17 and the peg 29 locating within a slot 31 of the bolt 1. The slot 31 is of a dog-leg configuration having a first portion 32 formed as an arc of constant radius centred on the pivot-pin 24 to provide for lost motion between the runner 17 and bolt 1, and a second portion 33 parallel to the line of movement of the runner 17, to draw the bolt 1 back and forth during upward and downward movement respectively, of the runner 17.
The path of movement of the runner 17 is constrained to a line at right angles to that of the bolt 1, generally by the slots 16 and 26 running on the pins 15 and 24, but principally by a peg 34 (identified in Figure 1). The peg 34 is carried by a lath-part 35 of the runner 17 that is partially overlapped by the bolt 1 and runs within a slot 36 in the casing 2. Sliding movement of the bolt 1 across the lath-part 35 is blocked, thereby deadlocking the bolt 1, when the lock is in the locked condition. In the latter respect the lath-part 35 turns up at its end to form a shoulder 37 that runs along the rear wall 38 of the casing 2 (thereby aiding the peg 34 in guiding the runner 17) and projects into the plane of bolt-movement. The shoulder 37 lies in the withdrawal-path of the extended bolt 1 - as illustrated in Figures 1 and 4 - to lie immediately behind the bolt 1 and in abutment with the wall 38, so as to obstruct withdrawal movement of the bolt 1 until the runner 17 has been moved upwardly a small distance by clockwise turning of the correct key in the lock.
Clockwise turning of the correct key in the lock moves the runner 17 upwardly from its position illustrated in Figures 1 and 4 under the action of the thrower-rib 9 on the talon 22. This movement is translated through the peg 28 retained in the notch 30, into clockwise turning (with respect to Figures 1 and 4) of the bell-crank element 23 on its pivot-pin 24. The peg 29 initially moves along the first portion 32 of the slot 31 without moving the bolt 1 from its outward, locked position, until, as illustrated by Figure 6, the second portion 33 of the slot 31 is reached. The shoulder 37 is now clear of the path of the bolt 1, and continued clockwise turning of the key, and consequently of the bell-crank element 23 in response to the further upward movement of the runner 17, causes the bolt 1 to be withdrawn. The peg 29 in this respect runs along the second portion 33 of the slot 31, drawing the bolt 1, guided by the peg 5 in the recess 6, back through the aperture 3. The bolt 1 slides transversely across the lath-part 35 until withdrawal is complete as illustrated in Figure 7.
The action of the bolt mechanism in extending the bolt 1 from the inward, unlocked position illustrated in Figure 7, is the reverse of that described above. Rotation of the correct key in the anti-clockwise sense draws the runner 17 downward and turns the bell-crank element 23 anti-clockwise. This turning of the element 23 moves the peg 29 down the second portion 33 of the slot 31, thereby urging the bolt 1 outwardly through the aperture 3. The bolt 1 is fully extended when the peg 29 reaches, as illustrated in Figure 6, the first portion 32 of the slot 31. The further anti-clockwise rotation of the element 23 as the runner 17 continues to move downwardly and the peg 29 runs down the portion 32 of the slot 31 to the position illustrated in Figures 1 and 4, is lost to the bolt 1. The downward movement of the runner 17, however, reintroduces the shoulder 37 between the bolt 1 and the rear wall 38 so as to dealock the bolt 1 once again.
The deadlocking of the bolt 1 is especially secure in that it is provided by direct abutment of the bolt 1 upon the runner 17 as supported against the rear wall 38 of the casing 2. There is accordingly a very positive and solid block against forcing of the bolt 1, and this is entirely independent of operational items of necessarily- limited strength, such as the stump 18, the levers 13 and the pivot pin 15. Moreover, the portion 32 of the dog-leg slot 31 is configured to ensure that forcing of the bolt 1 does not act on the peg 29. In this respect, and as illustrated by Figure 8, the lower end of the portion 32 where the peg 29 is located while the bolt 1 is deadlocked, is enlarged slightly towards the forend of the lock to form a relief part 39. This ensures that any slight backward movement of the bolt 1 that may occur under forcing before the deadlock-blocking of the bolt 1 becomes fully effective, is not applied to the peg 29 and is accordingly not transmitted through the bell-crank element 23. The relief part 39 is of limited extent being in particular restricted to the lower end of the portion 32, so that the bolt 1 is not free to obstruct entry of the shoulder 37 behind it during the final phase of anti-clockwise rotation of the key while the deadlocked condition is being established.
The construction of lock mechanism described above has the added advantage that for any particular bolt-throw, it can in general be accommodated within a smaller depth than achievable using conventional constructions. This is especially noteworthy where the lock is for fitting to a door having a narrow stile. In one example of lock constructed as described, the depth from the outer of the forend to the rear wall of the casing is some 55 mm, accommodating a bolt of some 50 mm in overall length for a throw of some 20 mm. The same could be realised with a casing-depth of only 50 mm if turning of the key through 180° rather than the full 360° were acceptable.
With the mechanism of the present invention it is readily possible to provide that the throw of the bolt is different from the displacement of the runner. More particularly, the intercoupling of the runner 17 with the bolt 1 provided by the bell-crank element 23 in the above example, enables the throw of the bolt 1 to be significantly larger than the displacement of the runner 17 effected by the key. With the example of lock construction as referred to above having a bolt-throw of some 20 mm, the displacement of the runner 17 to produce this throw is only some 14 mm.

Claims

1. A lock in which linear movement of a slide or runner (17) that is coupled to the bolt (1) of the lock is communicated via the coupling (23) to extend or withdraw the bolt (1), according respectively to the direction of runner movement, transversely of the line of movement of the runner (17), characterised in that a part (37) carried with the runner (17) is moved into the withdrawal path of the bolt (1), so as to block withdrawal of the bolt (1), under movement of the runner (17) in the direction for extending the bolt (1), and that said coupling (23) between the runner (17) and bolt (1) provides lost motion between them such that movement of the runner (17) in the direction for withdrawal of the bolt (1) is communicated to the bolt (1) via the coupling (23) only after the runner (17) has moved sufficiently to clear said part (37) from the withdrawal-path of the bolt (1).

2. A lock according to Claim 1 in which the runner (17) is coupled to the bolt (1) by a bell-crank coupling (23) that engages with a slot (31) or groove on the bolt (1) for transmitting runner movement to the bolt (1), further characterised in that the slot (31) or groove is of dog-leg configuration (32, 33) to provide the lost motion between the runner (17) and bolt (1).

3. A lock according to Claim 2 further characterised in that the slot (31) or groove is configured (39) to provide that forcing of the bolt (1) in its withdrawal direction is resisted by abutment of the bolt (1) with said part (37) before such forcing is effective to create reaction between the bolt (1) and said coupling (23).

4. A lock according to any one of the preceding claims further characterised in that the said part is a shoulder (37) of the runner (17).

5. A lock according to any one of the preceding claims further characterised in that the said part (37) lies immediately behind the bolt (1) and in abutment with a portion (38) of a casing (2) of the lock when blocking withdrawal of the bolt (1) as aforesaid.

6. A lock according to Claim 5 further characterised in that the said portion of the lock casing is a wall (38) of the casing (2), and that the said part (37) of the runner (17) runs along this wall (38) throughout movement of the runner (17).