GB2036162A - Locks - Google Patents

Abstract

A lock has a runner (17) whose movement under turning of a correct key in the lock, is at right angles to that of the bolt (1). The runner (17) is coupled to the bolt (1) by a bell-crank (23) that engages via a peg (29) with a dog-leg slot (31) of the bolt (1). A shoulder 37 of the runner (17) bears on the casing rear-wall (38) and lies immediately behind the bolt (1) for deadlocking it. Upward movement of the runner (17) under clockwise turning of the key is lost to the bolt (1) initially as the peg (29) traverses a first portion (32) of the slot (31), allowing the shoulder (37) to move clear before withdrawal of the bolt (1). Anti-clockwise turning of the key returns the runner (17), the peg (29) entering the lost-motion slot- portion (32) again after the bolt (1) is re-extended, to allow reintroduction of the shoulder (37) behind the bolt (1). The lower end (39) of the slot (31) is enlarged to ensure that forcing of the bolt (1) is borne by the shoulder (37) alone. <IMAGE>

Description

SPECIFICATION Locks This invention relates to locks.

The invention is concerned particularly with 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 that coupling to extend or withdraw the bolt according to the direction of runner movement. Locks of this kind in which the runner is mounted to slide parallel to the path of the bolt, are known.

Such locks are commonly key operated, necessitating the insertion and turning of a correct key within the lock to bring about the movement of the runner required to extend or withdraw the bolt. The runner normally engages with a tail extending from the head of the bolt so as to draw the bolt along with the runner as the runner moves along its linear path, the bolt being thereby extended or withdrawn according to the sense in which the key is turned.

The use of a runner in the above way, enables a flexibility in construction and overall dimensioning to be achieved in lock design, as well as, possibly, increased security. But in general it is not readily possible to reduce the depth of the lock in this way. Such depth, measured parallel to the path of movement of the bolt, is dependent on the length and throw of the bolt required, and also on whatever additional space is necessary to accommodate the parallel-moving runner and its coupling to the bolt. Reduction in lock depth is desirable especially in view of the presentday tendency to provide doors and casements with narrower stiles than previously.

It is one of the objects of the present invention to provide a form of lock that may be utilized to enable significant reduction in lock-depth to be achieved.

According to the present invention there is provided a lock in which linear movement of a slide or runner that is coupled to the bolt of the lock is communicated via that coupling to extend or withdraw the bolt according to the direction of runner movement, wherein the line of movement of the runner is transverse to that of the bolt.

The line of movement of the runner is preferably at right angles to that of the bolt.

It may be arranged that a part carried with the runner is moved into the withdrawal-path of the bolt under movement of the runner in the direction for extending the bolt, so as to block withdrawal of the bolt while it is extended and until the runner is first moved in the opposite, withdrawal direction; this is of especial advantage for deadlocking the bolt and securing it against forcing. Coupling between the runner and bolt may provide for lost motion between them such that movement of the runner in the direction for withdrawal of the bolt is communicated to the bolt only after the runner has moved sufficiently to clear the said part from the withdrawal-path of the bolt. Such coupling furthermore, may enable the final movement of the runner which while the bolt is fully extended, is required to locate said part in its bolt-locking position.

The runner and bolt may be coupleld together through a bell-crank, and this readily enables the bolt movement to be effected with magnification from the runner movement.

Where lost motion as referred to in the preceding paragraph is to be provided, then this may conveniently be provided simply by appropriate configuration of a slot or groove in which the bell-crank engages with the bolt.

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 jn front elevation with its cover-plate removed and bolt extended; Figure 2 shows the inside face of the coverplate 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 Fig. 1 and showing more clearly its bolt and runner mechanism; Figure 5 is a view from the rear of a barreland-curtain element that forms part of the lock; Figures 6 and 7 are part-sectional elevations of the lock, corresponding to Fig. 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 Figs. 1 to 4, the locking bolt 1 when fully extended to its outward, locked position (shown in Figs. 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 (Fig. 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 appropriatelystepped key (not shown) inserted into a keyhole 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 which, as illustrated in Fig. 5, is provided as a slotted rib 9 on the underside of a barrel-and-curtain element 1 0. A leaf spring 11 engages a notch 1 2 in the element 10 to detain the rib 9 normally aligned with the keyhole 8.

Turning of the inserted key in either direction rotates the element 10 so as to disengage the notch 1 2 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 1 3 (Fig. 1). The levers 13, which are resiliently biased by individual springs 14, are stacked one upon the other on the pivot pin 1 5 that projects through a slot 16 (Fig. 4) in a runner 17.A stump 18 of the runner 1 7 is detained within one or the other or two racking slots 1 9 and 20 of each lever 1 3 in the stack, being detained in the slot 1 9 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 1 9 when so detained precludes movement of the runner 1 7 until the levers 1 3 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 1 3 will not be lifted the individually-required amount to bring its gating aperture 21 (inter-connecting the slots 19 and 20) into alignment with the stump 18, and movement of the runner 1 7 will accordingly continue to be precluded. With the correct key, on the other hand, all levers 1 3 are lifted just enough to align their gating apertures 21 with the stump 18 so as to free the runner 1 7 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 Fig. 4) formed in the runner 17.The sliding movement of the runner 1 7 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 Fig. 1. The action of the thrower-rib 9 on the talon 22 in this case slides the runner 1 7 in the direction to move the stump 1 8 out of the slot 1 9 into the slot 20 through the gating aperture 21 of each lifted lever 1 3. Continued turning of the key to return the rib 9 to alignment with the keyhole 8 and allow withdrawal of the key, releases the levers 1 3 causing them to spring back to detain the stump 1 8 in the racking slots 20 and so restrain return movement of the runner 1 7. Return movement of the runner 1 7 required to extend the bolt 1 to its outward, locked position, is achieved by turn ing the key in the opposite, anti-clockwise sense. This lifts levers 1 3 and again enables the stump 1 8 to pass through the gating aperture 21 of each lever 13-in this case from the slot 20 back into the slot 1 9-to restore the lock to the condition illustrated in Fig. 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 paths 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 shown in the drawings that enable realization of these and other advantages will now be described.

Referring again especially to Figs. 1 and 4, the stack of levers 1 3 is located to one side of the key-hole 8 so that the runner 1 7 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 1 7 is communicated to the bolt 1 via a bellcrank element 23 that is pivotted by a pin 24 which engages a hole 25 (Fig. 2) in the cover-plate 7, and which extends via a slot 26 in the runner 1 7 to engage a corresponding hole 27 (Fig. 3) in the casing 2.Two pegs 28 and 29 on the element 23 engage with the runner 1 7 and bolt 1 respectively, the peg 28 being retained within a notch 30 in the runner 1 7 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 1 7 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 1 7 is constrained to a line at right angles to that of the bolt 1, generally by the slots 1 6 and 26 running on the pins 1 5 and 24, but principally by a peg 34 (identified in Fig. 1). The peg 34 is carried by a lath-part 35 of the runner 1 7 and runs within a slot 36 in the casing 2. The lath-part 35 is partially overlapped by the bolt 1 within the casing 2, but 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 boltmovement. The shoulder 37 lies in the withdrawl-path of the extended bolt 1-as illustrated in Figs. 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 1 7 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 1 7 upwardly from its position illustrated in Figs. 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 Figs. 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 Fig. 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 path-part 35 until withdrawal is complete as illustrated in Fig. 7.

The action of the bolt mechanism in extending the bolt 1 from the inward, unlocked position illustrated in Fig. 7, is the reverse of that described above. Rotation of the correct key in the anti-clockwise sense draws the runner 1 7 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 illustrates in Fig. 6, the first portion 32 of the slot 31. The further anti-clockwise rotation of the element 23 as the runner 1 7 continues to move downwardly and the peg 29 runs down the portion 32 of the slot 31 to the position illustrated in Figs.

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 deadlock 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 1 7 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 1 3 and the pivot pin 1 5. 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 Fig. 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 bellcrank 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 casingdepth of only 50 mm if turning of the key through 180 rather than the full 360 where acceptable.

With the mechanism of the present inventiom 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 1 7 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 1 7 effected by the key. With the example of lock construction as referred to above having a bolt-throw of some 20 mm, the diaplacement of the runner 1 7 to produce this throw is only some 14 mm.

Claims (11)

1. A lock in which linear movement of a slide or runner that is coupled to the bolt of the lock is communicated via that coupling to extend or withdraw the bolt according to the direction of runner movement, wherein the line of movement of the runner is transverse to that of the bolt.

2. A lock according to Claim 1 wherein the line of movement of the runner is at right angles to that of the bolt.

3. A lock according to Claim 1 or Claim 2 wherein the runner is coupled to the bolt by a bell-crank coupling.

4. A lock according to Claim 3 wherein the bell-crank coupling engages with a slot or groove on the bolt for transmitting runner movement to the bolt.

5. A lock according to Claim 4 wherein the slot or groove is of dog-leg configuration to provide initial lost motion between the runner and bolt for movement of the runner in the direction to withdraw the bolt.

6. A bolt according to any one of the preceding claims wherein 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, said coupling between the runner and bolt providing 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.

7. A lock according to Claim 6 wherein the said part is a shoulder of the runner.

8. A lock according to Claim 6 or Claim 7 wherein the said part lies immediately behind the bolt and in abutment with a portion of a casing of the lock when blocking withdrawal of the bolt as aforesaid.

9. A lock according to Claim 8 wherein the said portion of the lock casing is a wall of the casing, the said part of the runner running along this wall throughout movement of the runner.

10. A lock according to Claim 4 or Claim 5 and any one of Claims 6 to 9 wherein the slot or groove is configured to provide that forcing of the bolt in its withdrawal direction is resisted by abutment of the bolt with said part before such forcing is effective to create reaction between the bolt and said coupling.

11. A lock according to any one of the preceding claims wherein the bolt partially overlaps the runner.

1 2. A key-operable lock substantially as hereinbefore described with reference to the accompanying drawings.