GB2431198A

GB2431198A - Bolt operating mechanism for a closure lock

Info

Publication number: GB2431198A
Application number: GB0620440A
Authority: GB
Inventors: Ray Massey
Original assignee: B & G Lock & Tool Co Ltd
Current assignee: B & G Lock & Tool Co Ltd
Priority date: 2005-10-15
Filing date: 2006-10-16
Publication date: 2007-04-18
Anticipated expiration: 2026-10-16
Also published as: GB2431198B; GB0620440D0; GB0521014D0

Abstract

A lock 1 for a closure comprises a bolt 7 operable by a cam 9 from one side of the closure and by a cam 11 from the other side of the closure. The bolt 7 is held in the bolted and unbolted positions by engagement of a control plate 21 with a fixed peg 19 and a floating peg 20. The cam 9 is operable to over-ride the cam 11 to disengage both pegs 19, 20 and release the control plate 21 for movement of the bolt 7 from the bolted position to the unbolted position even if the bolt 7 is being forcibly held in the bolted position by the cam 11. The cam 9 may be operated by a cylinder lock and the cam 11 may be operated by a thumb-turn.

Description

IMPROVEMENTS IN LOCKS

This invention concerns improvements in locks and is particularly concerned with a lock for a door or the like having a bolt that can be moved between bolted and unbolted positions via a drive mechanism which can be operated from either side of the door.

Doors for bathrooms, washrooms, toilets and the like are typically provided with a privacy lock that is operated by a thumb turn or similar manually operable actuator to advance/retract a bolt to lock/unlock the door from the inside by the occupant of the room.

Typically, the thumb turn operates a cam on a follower mounted on a rotatable spindle that extends through the door and means is provided for rotating the spindle from the other side of the door if it is necessary to open the door in an emergency, for example if the occupant is unable to unlock the door due to incapacity.

Such locks are well known and provide a simple way of unlocking the door from the outside in most situations. However, in circumstances where the thumb turn is held to prevent operation from the outside, the door cannot be unlocked and opened.

The present invention seeks to provide a solution to this problem.

Thus, according to one aspect of the present invention, there is provided a lock for a closure such as a door or window, the lock comprising a bolt movable between a retracted, unbolted position and an extended, bolted position by a drive mechanism operable from one side of the closure by a first means and from the other side by second means, wherein the first means is operable to over-ride the second means and return the bolt to the unbolted position if the bolt is held in the bolted position by the second means.

The first and second means may each comprise a rotatable cam operable to move the bolt between the bolted and unbolted positions. The rotatable cam of the first means may be provided by a cylinder lock and operable by a key that can be withdrawn from the lock in the bolted and unbolted positions. The rotatable cam of the second means may be provided by a follower mounted on a spindle operable by a thumb turn or similar device attached to the spindle.

The second means may be operatively connected to the bolt via a control plate that transmits drive from the follower cam to the bolt and the lock cam may disconnect the control plate to uncouple the second means to operate the bolt via the first means. In one arrangement the control plate is mounted on and moves with the bolt between the bolted and unbolted positions and the cylinder cam operates a release link to uncouple the control link from the second means.

The control plate may be engageable with a fixed peg on the lock casing to deadlock the bolt in the bolted and unbolted position and the follower cam may be releasably coupled to the control plate by a floating peg to operate the bolt with the second means. In one arrangement operation of the cylinder cam disengages both pegs to operate the bolt with the cylinder cam and, where necessary, to over-ride the follower cam, and operation of the follower cam disengages the fixed peg while maintaining engagement of the floating cam to operate the bolt with the follower cam.

According to another aspect of the present invention, there is provided a closure provided with a lock according to the preceding aspect of the invention.

The closure may be a door or window wherein a closure member is movable relative to a fixed frame between open and closed positions and can be secured in the closed position by the lock.

Preferably, the closure is a door providing access to a room such as a bathroom where the first means is provided on the outside of the door and the second means is provided on the inside of the door. As a result, the bolt can be moved to the unbolted position to enable the door to be opened from the outside by operation of the first means even if the bolt is being held in the bolted position by the second means. In this way, the first means can over-ride the second means to allow the door to be opened from the outside if an attempt is made from the inside of the door to retain forcibly the bolt in the bolted position with the second means so as to prevent the door being opened.

According to a still further aspect of the present invention, there is provided a lock for a closure, the lock comprising a bolt operable by a first rotatable cam from one side of the closure and by a second rotatable cam from the other side of the closure, the bolt being secured in the bolted and unbolted positions by engagement of a control plate with a first peg, a second peg arranged to couple the control plate to the second cam for movement to and from the bolted position under control of the second cam, and the first cam being operable to uncouple the control plate from the second peg for movement of the bolt from the bolted position to the unbolted position under the control of the first cam even if the bolt is being forcibly held in the bolted position by the second cam. 4 4

Other features, benefits and advantages of the invented lock will be understood from the description hereinafter of an exemplary embodiment.

The invention will now be described in more detail by way of example with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a lock according to the invention with part of the casing removed to show the arrangement of the internal components with the bolt in the unbolted condition; Figure 2 is a perspective view of the lock shown in Figure 1 with parts of the drive mechanism removed; Figure 3 is a perspective view of the lock shown in Figure 2 with more parts of the drive mechanism removed; Figure 4 is a perspective view of the lock shown in Figure 3 with more parts of the drive mechanism removed; Figure 5 is a perspective view of the lock shown in Figures 1 to 4 with the bolt in the bolted position following operation by a key from one side of the lock; Figure 6 is a perspective view of the lock shown in Figures 1 to 4 with the bolt in the bolted position following operation by a thumb turn from the other side of the lock; Figure 7 is a perspective view of the lock shown in Figure 6 with the bolt in the unbolted position following operation by the key; 4 5 Figure 8 is a perspective view of the lock shown in Figures 1 to 4 with the bolt advanced to a halfway bolted position by operation of the thumb turn; Figure 9 is a perspective view of the lock shown in Figure 8 with the bolt in the unbolted position following operation by the key; Figure 10 shows a modification to the control plate of the drive mechanism of the lock of Figures 1 to 9; and Figure 11 shows another modification to the control plate of the drive mechanism of the lock of Figures 1 to 9.

Referring first to Figures 1 to 6 of the accompanying drawings, a lock 1 according to the invention is shown comprising a rectangular casing 2 having a front plate 3 to which a cover plate 4 is releasably secured by screws 5.

The lock 1 further comprises a spring loaded latch bolt in the form of a roller 6 biased to project from the casing 2 through aligned apertures in the front plate 3 and cover plate 4 to engage a keeper (not shown) on a surrounding frame of the door to hold the door in a closed position.

In some views, the roller 6 is shown in a withdrawn position that occurs automatically when the door is opened/closed. Roller latch bolts of this type are well known in the art and are not described further herein as they form no part of this invention. Furthermore, it will be understood that the roller latch bolt may be replaced by any other type of latch bolt for holding the door in the closed position. In some applications, the latch bolt may be omitted.

The lock 1 further comprises a deadbolt 7 movable between an unbolted position shown in Figures 1 and 2, and a bolted position shown in each of Figures 5 and 6 in which the bolt 7 projects from the casing 2 to engage the keeper and secure the door in the closed position.

The bolt 7 is moveable between the unbolted and bolted positions by a drive mechanism 8 described in more detail below. The drive mechanism 8 is housed within the casing 2 and is operable from one side of the door by a cam 9 of a cylinder lock 10 and from the other side of the door by a cam 11 of a follower 12.

The cylinder lock 10 is operable by a key (not shown) to rotate the cam 9 to advance/retract the bolt 7. The follower 12 has a square bore 13 to receive a spindle (not shown) on which a manually operable actuator such as a thumb turn (not shown) is mounted to rotate the cam 11 to advance/retract the bolt 7.

The drive mechanism 8 has a generally Z-shaped link 14 located on a pair of pins 15, 16 that are mounted on the casing 2 and are received in slots 17, 18 in arms 14a, 14b of the link 14 such that the link 14 can move up and down in the direction of arrow A but is prevented from moving in the direction of arrow B transverse to the direction of arrow A. The boLt 7 is deadlocked in the unbolted and bolted positions by * engagement of square pegs 19, 20 with a control plate 21 according to operation of the lock by the key and thumb turn as described later.

The peg 19 is mounted on the casing 2 and projects through a slot 7a in the bolt 7 into a window 22 in the control plate 21. The window 22 has two recesses 22a,22b and the peg engages the left hand window as viewed in Figure 1 in the unbolted position of the bolt 7 and the right hand recess in the bolted position shown in Figures 5 and 6.

The peg 20 is mounted on a peg plate 23 and is received in a cut-out region 24 of the bolt 7 that also receives the follower 12. The peg plate 23 is mounted on a slide plate 25 by engagement of a pair of pins 26a,26b in slots 27a,27b such that the peg plate 23 can move up and down on the slide plate 25 in the direction of arrow A and can move with the slide plate 25 in the direction of arrow B transverse to the direction of arrow A. The cut-out region 24 has three recesses 24a,24b,24c that are engaged by the peg 20 in different conditions of the lock as described later.

The control plate 21 is located on top of the bolt 7 and has a pair of elongate slots 28a,28b in which a pair of pins 29a,29b on the bolt 7 are received such that the control plate 21 can move up and down on the bolt 7 in the direction of arrow A and moves with the bolt 7 in the direction of arrow B transverse to the direction of arrow A. The follower 12 is received in a window 30 of a plate 31 that also receives a pair of pins 32a,32b mounted on the casing 2. The plate 31 has a pair of slots 31a,31b. The slot 31a receives a pin 32c that is mounted on the casing 2 and extends through a slot 25a in the slide plate 25. The slot 31b receives the pin 16. The arrangement of the pins 32a,32b,32c and 16 is such that the plate 31 can move up and down in the direction of arrow A and is prevented from moving in the direction of arrow B transverse to the direction of arrow A. Figures 1 to 3 show the bolt 7 in the retracted or unbolted position with the cam 9 of the cylinder lock 10 and the cam 11 of the follower 12 in the open or inoperative positions.

The bolt 7 can be moved from this position to the extended or bolted position shown in Figure 5 by inserting a key in the cylinder lock 10 and rotating the cam 9 in an anticlockwise direction from the position shown in Figure 1. As the cam 9 rotates it engages a curved projection 14d on a centre portion 14c of the link 14. This raises the link 14 which in turn raises the control plate 21 in the direction of arrow A to disengage fixed peg 19 from the left hand recess 22a and floating peg 20 from the centre recess 24b thereby releasing the bolt 7 for sliding movement to the bolted position in the direction of arrow B. A pair of plates 50,51 are pivotally mounted on the underside of the bolt 7 by engagement of a pin (not shown) in aligned holes 50a,51a in the plates 50,51. The plates 50,51 have aligned trapezoidal slots 50b,51b in which a square peg (not shown) on the underside of the bolt 7 is received and the plates 50,51 are biased to an operative position shown in Figure 1 in which a finger 51c on the plate 51 is received in a cut-out 34 in the tail end of the bolt 7 by a spring (not shown) located in the slots 50b,51b between the plates 50,51 and the peg. As the cam 9 rotates it engages the finger 51c and moves the bolt 7 to the bolted position.

The control plate 21 moves to the left with the bolt 7 as viewed in Figure 1 as the bolt 7 moves to the bolted position and, when the bolt 7 reaches the bolted position, the control plate 21 drops under the biasing of a spring (not shown) in the slot 28a to locate the peg 19 in the right hand recess 22b as shown in Figure 5. During this movement, the slide plate 25 and peg plate 23 remain in the their original position and the floating peg 20 locates in the right hand recess 24c as shown in Figure 5.

The bolt 7 is now deadlocked in the bolted position.

A stop plate 52 pivotally mounted on the pin 16 has a slot 52a in which a peg (not shown) on the underside of the bolt 7 is received. As the bolt 7 moves to the bolted position, the plate 52 pivots in a clockwise direction to a position in which a leg 52b blocks rotation of the cam 9 in an anticlockwise direction. In this way, after moving the bolt 7 to the bolted position, the plate 52 prevents the cam 9 being rotated in an anticlockwise direction to lift link 14 and control plate 21 to disengage the pegs 19,20 and release the bolt 7.

The bolt 7 can be returned to the unbolted position of Figure 1 by reverse operation of the cylinder lock 10 to rotate the cam 9 in a clockwise direction to engage the link 14 to lift the control plate 21 to disengage the pegs 19,20 from the recesses 22b,24c and release the bolt 7 for return movement to the unbolted position by engagement of the cam 9 with the tail end of the bolt 7 On reaching the unbolted position, the control plate 21 again returns to its original position under the biasing of the spring to locate the pegs 19,20 in the recesses 22a,24b to deadlock the bolt 7 in the unbolted position show in Figure 1. Another stop plate 53 pivotally mounted on a pin 54 on the case 2 has a slot 53a in which a pin 31c on the underside of the plate 31 is received. When the bolt 7 is in the unbolted position, the plate 50 engages the stop plate 53 (see Figure 4) and prevents the plates 50,51 pivoting upwards. As a result, the plate 50 blocks rotation of the cam 9 in a clockwise direction from the position shown in Figure 1.

dl' 10 As will be appreciated, the above key operation of the lock using the cam 9 is achieved independently of the cam 11 on the follower 12 associated with the thumb turn which remains in the same position throughout the movement of the bolt 7 between the unbolted and bolted positions under the control of the cylinder lock 10.

The bolt 7 can also be moved from the unbolted position of Figure 1 to the bolted position shown in Figure 6 by operating the thumb turn to rotate the cam 11 in an anticlockwise direction from the position shown in Figure 1. As the cam rotates it engages and lifts plate 31 which lifts the peg plate 23 which in turn lifts the control plate 21 to disengage the fixed peg 19 from the left hand recess 22a and release the bolt 7 for sliding movement to the bolted position. In this condition, the floating peg 20 remains engaged in centre recess 24b and, as the cam 11 is rotated in an anticlockwise direction, the slide plate 25 moves to the left in the direction of arrow B taking with it the peg plate 23, the control plate 21 and the bolt 7.

When the bolt 7 reaches the bolted position, the control plate 21 drops under the biasing of the spring to locate the fixed peg 19 in the right hand recess 22b as viewed in Figure 6 to deadlock the bolt 7 in the bolted position. Throughout this operation, the floating peg 20 remains in the centre recess 24b to operatively connect the cam 11 to the bolt 7 through the control plate 21.

The bolt 7 can be returned to the unbolted position of Figure 1 by reverse operation of the thumb turn to rotate the cam 11 in the clockwise direction to lift plate 31 to disengage the fixed peg 19 from the right hand ii recess 22b and release the boLt 7 for return movement to the unlocked position together with the control plate 21 and slide plate 25.

On reaching the unbolted position, the control plate 21 drops to locate the fixed peg 19 in the left hand recess 22a to deadlock the bolt 7 in the unbolted position. Throughout this operation, the floating peg 20 remains in the centre recess 24b to operatively connect the cam 11 to the bolt 7 through the control plate 21. As will be appreciated, the above operation is achieved independently of the cam 9 on the cylinder lock 10 which remains in the same position throughout the movement of the bolt 7 between the unbolted and bolted positions under the control of the thumb turn.

In use, the lock may be mounted in the stile of a door for a bathroom or washroom where the thumb turn is provided on the inside of the door to allow a person entering the room to lock/unlock the door from the inside.

The door can also be locked/unlocked from the outside by inserting the appropriate key in the cylinder lock 10. In this way, a person using the room can lock/unlock the door to have privacy while using the facility and the door can be locked/unlocked from the outside by a key holder when it is desired to prevent use of the room, for example if the facilities are broken or damaged.

In addition to the above operation of the lock, the drive mechanism 8 also allows the bolt 7 to be moved to the unbolted position by operation of the cylinder lock 10 following operation by the thumb turn to fully or partially advance the bolt 7 as now described with reference to Figures 6 to 9.

Figure 6 shows the bolt in the bolted position following operation by the thumb turn as described above. On rotation of the cam 9 of the cylinder lock 10 in a clockwise direction from the position shown in Figure 6, the cam 9 passes finger 51c on plate 51 and engages the curved projection 14d on the link 14 to raise the link 14 which lifts control plate 21 to disengage the fixed peg 19 from the right hand recess 22b and floating peg 20 from the centre recess 24b thereby releasing the bolt 7 for return movement to the unbolted position shown in Figure 7 together with the control plate 21. During this movement, the slide plate 25 and peg plate 23 are uncoupled from the control plate 21 and remain in the position adopted when the bolt 7 was moved to the bolted position by the thumb turn.

When reaching the unbolted position, the control plate 21 drops under the biasing of the spring to locate the peg 19 in the left had recess 22a and floating peg 20 in the left hand recess 24a to deadlock the bolt 7 in the unbolted position. As will be appreciated this operation over-rides the cam 11 on the follower 12 which remains in the position reached when used to move the bolt to the bolted position as shown in Figure 6. In this way, the door can be unlocked from the outside using the key to operate the cylinder lock 10 if the door has been locked from the inside using the thumb turn and the person is then unable to unlock the door from the inside or deliberately attempts to prevent the door being opened by holding the thumb turn in the locked position.

Referring now to Figures 8 and 9, these show operation of the thumb-turn to move the bolt 7 to a partially extended position sufficient to lock the door in the closed position using the thumb turn, and operation of the cylinder lock 10 to over-ride the thumb-turn and return the bolt 7 to the A 13 unbolted position if an attempt is made to prevent the door being opened by holding the thumb turn with the bolt 7 partially extended.

More specifically, Figure 8 shows the operation of the lock using the thumb turn to rotate the cam 11 on the follower 12 to partially advance the bolt 7 from the unbolted position shown in Figure 1. The fixed peg 19 is disengaged from the left hand recess 22a and the floating peg 20 is engaged in the centre recess 24b on the control plate 21 to couple the bolt 7 to the slide plate 25 for movement towards the bolted position.

In this position, the stop plate 53 has been pivoted clear of the plate 50 in response to upward movement of the plate 31 by the cam 11. As a result, if the thumb turn is held in this position and the cylinder lock rotated in a clockwise direction, the cam 9 will engage plate 50 which can now pivot upwards with plate 51 to allow the cam 9 to pass the finger 51c. The cam 9 then lifts link 14 to raise the control plate 21 to disengage the floating peg 20 from the centre recess 24b to uncouple the control plate 21 from the peg plate 23 and sliding plate 25 so as to over- ride the cam 11 on the follower 12 and allow the bolt 7 to return to the unbolted position shown in Figure 9 under control of the cylinder lock 10 independently of the thumb turn.

As will now be appreciated, the above embodiment provides a lock, primarily for a door, which can be operated from either side of the door and which enables operation from one side to over-ride operation from the other side to unlock the door if access is required for any reason. For example, to enable the door to be unlocked from the outside to open the door in an emergency after it has been locked (fully or partially) from the inside by a person who is then unable or unwilling to unlock the door.

Referring now to Figure 10 in combination with Figures 1 to 9. there is shown a modification to the control plate of the drive mechanism abovedescribed in which like reference numerals are used to indicate corresponding parts.

In this modification, the control plate 21 has a cam face 24d that is engaged by floating peg 20 if the follower 12 on the cam 11 is rotated in an anticlockwise direction from the bolted position shown in Figure 5 with the bolt 7 extended by operation of the cylinder cam 9. As a result, the control plate 21 is lifted as the floating peg 20 moves to the left as viewed in Figure 5 until the peg 20 is aligned with the recess 24b and the control plate 21 drops down under the spring biasing to engage the floating peg 20 in the recess 24b with the bolt 7 as shown in Figure 6.

The lock can then be operated to retract the bolt 7 to the unbolted position by rotation of cam 11 in the clockwise direction from the position shown in Figure 6. In this way, if the lock is locked from the outside by the cylinder cam 9, the lock can be unlocked from the inside, for example in an emergency, by the cam 11.

Referring now to Figure 11 in combination with Figures 1 to 9, there is shown another modification to the control plate of the drive mechanism above-described in which like reference numerals are used to indicate corresponding parts.

In this modification, the control plate 21 has an abutment 24e that maintains engagement between the floating peg 20 and the control plate 21 if the cylinder cam 9 is rotated in an anticlockwise direction from the unbolted position shown in Figure 1. As a result, the control plate 21 is not released and the bolt 7 cannot be moved to the bolted position by operation of the cylinder cam 9. The bolt 7 can still be moved to the bolted position shown in Figure 6 by operation of the cam 11 from the inside following which the bolt 7 can be returned to the unbolted position by the cam 11 from the inside or by the cylinder cam 9 from the outside.

In this way, the lock can be unlocked from the outside by the cylinder cam 9 after being locked from the inside, for example in an emergency or if the thumb turn is being held on the inside with the bolt 7 partially or fully extended.

Claims

1. A lock for a closure, the lock comprising a bolt movable between a retracted, unbolted position and an extended, bolted position by a drive mechanism operable from one side of the closure by a first means and from the other side by second means, wherein the first means is operable to over-ride the second means and return the bolt to the unbolted position if the bolt is held in the bolted position by the second means.

2. A lock according to claim 1 wherein the first and second means each comprise a rotatable cam operable to move the bolt between the bolted and unbolted positions.

3. A lock according to claim 2 wherein the rotatable cam of the first means is provided by a cylinder lock operable by a key that can be withdrawn from the lock in the bolted and unbolted positions.

4. A lock according to claim 2 or claim 3 wherein the rotatable cam of the second means is provided by a follower mounted on a spindle operable by a thumb turn or similar device attached to the spindle.

5. A lock according to claim 4 wherein the second means is operatively connected to the bolt via a control plate that transmits drive from the follower cam to the bolt.

6. A lock according to claim 5 wherein the lock cam can disconnect the control plate to uncouple the second means to operate the bolt via the first means.

7. A lock according to claim 5 or claim 6 wherein the control plate is mounted on and moves with the bolt between the bolted and unbolted positions and the cylinder cam operates a release link to uncouple the control link from the second means.

8. A lock according to claim 7 wherein the control plate is engageable with a fixed peg on the lock casing to deadlock the bolt in the bolted and unbolted positions.

9. A lock according to claim 8 wherein the follower cam is releasably coupled to the control plate by a floating peg to operate the bolt with the second means.

10. A lock according to claim 9 wherein both pegs are disengaged by operation of the cylinder cam in the bolted position of the bolt to release the control plate such that movement of the bolt to the unbolted position with the cylinder cam is permitted.

11. A lock according to claim 9 or claim 10 wherein both pegs are disengaged by operation of the cylinder cam in the unbolted position of the bolt to release the control plate such that movement of the bolt to the bolted position with the cylinder cam is permitted.

12. A lock according to claim 9 or claim 10 wherein the fixed peg is disengaged and the floating peg remains engaged by operation of the cylinder cam in the unbolted position of the bolt such that movement of the bolt from the unbolted position to the bolted position with the cylinder cam is prevented. a 18

13. A lock according to any one of claims claim 9 to 12 wherein the fixed peg is disengaged and the floating peg remains engaged by operation of the follower cam in the bolted position of the bolt such that movement of the bolt from the bolted position to the unbolted position with the follower cam is permitted.

14. A lock according to any one of claims claim 9 to 13 wherein the fixed peg is disengaged and the floating peg remains engaged by operation of the follower cam in the unbolted position of the bolt such that movement of the bolt from the unbolted position to the bolted position with the follower cam is permitted

15. A closure provided with a lock according to any preceding claim.

16. A closure according to claim 15 comprising a door or window wherein a closure member is movable relative to a fixed frame between open and closed positions and can be secured in the closed position by the lock.

17. A closure according to claim 16 wherein the closure is a door providing access to a room where the first means is provided on the outside of the door and the second means is provided on the inside of the door.

18. A closure according to claim 17 wherein the bolt can be moved to the unbolted position to enable the door to be opened from the outside by operation of the first means even if the bolt is being held in the bolted position or a partially bolted position by the second means.

19. A closure according to claim 18 wherein the first means is operable to over-ride the second means to allow the door to be opened from the outside if an attempt is made from the inside of the door to retain forcibly the bolt in the bolted or partially bolted position with the second means so as to prevent the door being opened.

20. A lock substantially as hereinbefore described with reference to the accompanying drawings.