GB2039983A - Automatic deadlock - Google Patents

Abstract

An automatic deadlock has a release 31 latch which holds a bolt in a retracted position. A locking member 21 is provided which is moved on closure of the door, the movement releasing the release latch to allow the bolt to shoot under the action of a compressed spring 26. Retraction is prevented by pawl 29. Released by arm 25 on lock 22. <IMAGE>

Description

SPECIFICATION Automatic deadlock It is normal practice with factory premises, shops, offices, etc., to use a deadlock to secure all external doors. Such locks are secure in that the deadlock resists attack by a lever being used to exert a longitudinal force against the bolt. There is a major problem with this type of lock in that, when leaving the premises, a key must be used to place the lock in the secure position. With doors which are in continual use throughout the day, it is usual to supplement the deadlock with a spring loaded latch which can be withdrawn by the use of a knob or handle. To all intents the door has the appearance of being locked and security is dependent on the last person leaving the building remembering to secure the lock.

Domestic premises in the majority of cases use a latch type lock to secure the main entrance door, this type being convenient to use as the door is locked merely by slamming the door, a key being used to gain entry. Security is of a very low order as the bolt can be pushed back by spring steel or a plastic card.

Security is enhanced by fitting a deadlock but its effectiveness is dependent on the user securing the lock when vacating the premises or retiring for the night. At least one door must be locked in a manner which permits exit without the use of a key as a precaution in case of fire; this prevents the use of a conventional warded key type deadlock.

Hotels present a major security problem where people of many origins cannot be educated to secure a deadlock when vacating the room; the low level security spring loaded latch is used which is open to simple attack by the methods described.

It is an object of the invention to mitigate these disadvantages.

According to the invention, there is provided an automatic deadlock comprising a bolt urged by a spring into a keep-engaging position, a deadlock latch movable into and out of a bolt-engaging position occupied by the deadlock latch when the bolt is in the keep-engaging position to prevent forced retraction of the bolt, the bolt being retracted to compress the spring and the deadlock latch leaving the bolt-engaging position on operation of a manually operable member and being held in a retracted position by a release latch, a locking member projecting from the deadlock when the bolt is in the retracted position and being movable to disengage the release latch from the bolt, the bolt then moving under the action of the compressed spring to the keep-engaging position where the bolt is reengaged by the deadlock latch.

The following is a more detailed description of two embodiments of the invention by way of example, reference being made to the accompanying drawings, in which: Figure 1 is an elevation from one side of an automatic deadline of a first embodiment of the invention with a bolt of the automatic deadline in a retracted position.

Figure 2 is a section on the line ll-ll of Figure 1.

Figure 3 is a plan view from above of the automatic deadlock of Figures 1 and 2, partially broken-away, Figure 4 is an elevation from said one side of the automatic deadlock of Figures 1 to 3 but with the bolt in a keep-engaging position, Figure 5 is a section on the line V-V of Figure 4, Figure 6 is a section onto line VI-VI of Figure 4, Figure 7 is an elevation from one side of a modified form of the automatic deadlock of Figures 1 to6, Figure 8 is a plan view from above of the automatic deadlock of Figure 7, Figure 9 is a side elevation from one side of an automatic deadlock of a second embodiment of the invention with a bolt of the automatic deadlock in a keep-engaging position, Figure 70 is a section on the line X-X of Figure 9, Figure 11 is a plan view from above of the automatic deadlock of Figures 9 and 10, Figure 12 is a section from one side of a part of the automatic deadlock of Figures 9 to 11 with a locking member of the deadlock in a locking position, and Figure 13 is a similar view to Figure 12 but with the locking member out of the locking position and the bolt retracted.

Referring first to Figures 1 to 6, the automatic deadlock shown in these figures is for insertion into a door and for co-operation with a keep 18 mounted on a door frame of the door in a position to co-operate with the automatic deadlock. As seen in Figure 1, the automatic deadlock has a bolt 20 and a latch 21 and the keep is provided with an aperture 19 for the bolt 20; no aperture is provided for the latch 21.

The automatic deadlock comprises a profile cylinder 22 which is secured in a lockcase 23 of the deadlock by a screw 24. Such a cylinder 22 can be obtained with a number of variations; key operated on both sides, as shown in Figures 2 and 3, or operated from one side only, the operation being by key, or key operated at one side and operated by a knob or handle at the other side. Operation of the profile cylinder 22 from either side rotates a cam 25 from the position shown in Figure 1 in a clockwise direction, as seen in Figure 1.The bolt 20 is mounted for rectinlear sliding movement in the lockcase 23 and, in the retracted position shown in Figure 1, compresses a spring 26. The bolt 20 includes a cutout portion 27 on a lower surface for co-operation with the cam 25 and a notch 28 on an upper surface for co-operation with a deadlock latch 29 described in more detail hereinafter.The upper surface of the bolt 20 also includes a further notch 30 which, in the position shown in Figure 1, is engaged by a peg 31 mounted on one limb of a bell crank shaped release latch 32 pivotally mounted on the lockcase 23. The other limb of the release latch is connected to a rod carrying the lock member 21 at opposite end thereof.

A spring 33 urges the locking member 21 out of the lockcase and thus urges the peg 31 into the further notch 30.

The deadlock latch 29 is square in shape (see Figure 1) and is pivoted on the lockcase 23 about the same axis as the release latch 32. The square deadlock latch 29 is formed with a tooth 34 for engagement with the first-mentioned notch 28 in a manner described below. A spring 35 urges the tooth 34 towards the upper surface of the bolt 20.

In use, the position of the deadlock shown in Figures 1 to 3 is that adopted by the deadlock when the door is open or ajar. When the door is closed, the locking member 21 strikes the keep and since there is no aperture for the locking member 21, this member is forced inwardly of the lockcase 23. This movement compresses the spring 33 and rotates the release latch 32 in a clockwise direction as viewed in Figures 1 and 4. This rotation removes the peg 31 from the further notch 30 and the force of the compressed spring 26 shoots the bolt 20 into its aperture 19 in the keep 18 thus locking the door. In this keep-engaging position of the bolt 20, the tooth 34 of the deadlock latch 29 enters the first mentioned notch 28. Any longitudinal force exerted on the bolt 20 is resisted by the deadlock latch 29.Figures 4, 5 and 6 show the deadlock latch with the bolt 20 in the keep-engaging position.

To unlock the door, a key is inserted into the profile cylinder 22 from either side of the door. The key is turned to rotate the cam 25 in a clockwise direction as viewed in Figure 4. Initially, the cam 25 contacts a lower surface of the deadlock latch 29 to pivot the deadlock latch 29 against the action of the spring 35 to lift the tooth 34 out of the firstmentioned notch 28. This allows movement of the bolt 20. The cam 25 then engages in the cut-out portion 27 of the bolt and retracts the bolt from the keep-engaging position shown in Figure 4 to the retracted position shown in Figure 1. As the door is opened, the locking member 21 extends from the lockcase 23 under the action of the spring 33 and this movement pivots the release latch 32 in the anticlockwise direction as viewed in Figure 4.This movement reinserts the peg 31 in the further notch 30 in the bolt 20, thus holding the retracted bolt 20 with the spring 26 compressed.

The locking of the door is achieved in the manner described above.

If the deadlock latch 29 is made from a number of differently shaped pieces which correspond to wards on a key, then the operation described above with reference to Figures 1 to 6 can be achieved without the use of a profile cylinder.

Referring next to Figures 7 and 8, there is shown a modified form of the automatic deadlock of Figures 1 to 6. There are a number of parts common to the embodiment of Figures 7 and 8 and these parts bear the same reference numerals in both sets of figures and will not be described in detail.

In the embodiment of Figures 6 and 7, the profile cylinder 22 is operated from one side only and the operation is by use of a key. Generally, the profile cylinder 22 will be arranged to be operated from that side of the door which is the outside of the room to which the door provides an entrance and an exit.

On the other side of the deadlock there is mounted a knob 36 (Figure 8) which is rotatable on a spindle 37, the spindle being spaced to one side of the profile cylinder 22. The end of the spindle 37 remote from the knob 36 carries a cam 38 which is rotatable by turning the knob 36 clockwise from the position shown in the Figure 7.

The bolt 20 includes a second cut-out portion 39 spaced along the bolt from the first cut-out portion 27 and so located that in the keep-engaging position of the bolt 20 shown in Figure 7 the further cut-out portion is adjacent a leading end of the cam 38.

The only difference in operation between the deadlock of Figures 1 to 6 and the deadlock of Figures 7 and 8 occurs when the door is being opened from the inside. In this case, the knob 36 is turned and the leading end of the cam 38 lifts the square deadlock latch 29 to remove the tooth 34 from the notch 28. Further rotation of the knob 36 engages the leading end of the cam 38 in the further cut-out portion 39 to retract the bolt 20 from the keep aperture 19. As the door is opened, the locking member 21 extends from the lockcase 23 to insert the peg 31 in the further notch 30 thus holding the bolt 20 in the retracted position.

Referring next to Figures 8 to 13, in these figures there is shown a second embodiment of automatic deadlock. Certain parts of this second embodiment correspond to and operate in the same manner as parts in the embodiment described above with reference to Figures 1 to 8. These parts bear the same reference numerals in both sets of figures and will not be described in detail.

The deadlock of Figures 9 to 13 uses a special type of profile cylinder 40. As best seen in Figures 10 and 11, the second profile cylinder 40 includes two cams 41,42. The first cam 41 is rotated independently of the second cam 42 from that side of a door 43 on which the deadlock is mounted which is the outside of a room of which the door forms an entrance and an exit. The rotation is by a first key (not shown). The second cam 42 is rotated independently of the first cam 41 by means of a knob 44 on the inside of the door. The profile cylinder 40 is such that by use of a second key from the outside of the door both cams 41,42 may be rotated together.

As seen in Figures 9 and 10, two square deadlock latches, 45,46, are provided, one deadlock latch 45 being associated with the outside cam 41 and the other deadlock latch 46 being associated with the inside cam 42. The outside deadlock latch 45 carries a pin 47 (see Figure 10) which extends through a slot 48 provided in the inside deadlock latch 46. In addition, the outside deadlock latch 45 has a lower edge 49 which is situated above the lower edge 50 of the inside deadlock latch 46.

The upper surface of the bolt 20 is provided with two curved notches 51, 52 spaced apart along the length of the bolt 20.

A restriction latch 53 mounted above the deadlock latches 45, 46 and comprises a shaft rotatable by a thumb piece 56 from the inside of the door and from outside the lockcase, to move two legs 54, 55. The operation of the restriction latch 53 will be described in more detail hereinafter.

In the position of the deadlock shown in Figure 9, the bolt 20 is in its keep-engaging position and the pin 47 engages in one of the curved notches 52 to prevent unauthorized withdrawal of the bolt 20. If the first key is inserted in the exterior lock of the profile cylinder 40 and turned, the outside cam 41 will rotate until it contacts the lower edge 49 of the outside deadlock latch 45. Continued rotation will lift the outside deadlock latch and, due to the interconnection between the two latches provided by the pin 47, will also lift the inside deadlock latch 46 thus removing the pin 47 from the curved notch 52 to allow withdrawal of the bolt 20. Further rotation of the outside cam 41 will engage that cam in the cut-out portion 27 to retract the bolt; the retracted bolt being held in position by engagement of the peg 31 in the further notch 30.

If the door is opened from the inside by use of the knob 44, rotation of the knob 44 will rotate the inside cam 42 which initially will engage the lower edge of 50 of the inside deadlock latch 46 to lift the inside deadlock latch 46. After the pin 27 has travelled the length of the slot 48, the inside deadlock latch 46 will connect with the outside deadlock latch 45 so that both deadlock latches 45,46 are lifted together to remove the pin from the curved notch 52 thus allowing the bolt 20 to be withdrawn.

The rotating inside cam 42 will then enter the cut-out portion 27 to retract the bolt 20. The bolt 20 will be retained in the retracted position by engagement of the peg 31 in the further notch 30.

If a person within the room having a door closed by the deadlock wishes not to be disturbed, then that person turns the thumb piece 56 of the restriction latch 53 until the legs 54, 55 are in the position shown in Figure 12. In this position, one limb 54 is arranged vertically and engages with an upper surface of the outside deadlock latch 45. This leg 54 does not interfere with the movement of the inside deadlock latch 46 (see Figure 10). The second leg 55 is angularly spaced from the first leg 54 and, in this position, has an end adjacent to the upper surface of the inside deadlock latch 46. When the door is closed, the remaining components of the deadlock latch are as shown in Figure 9.

If an endeavour is made to open the door from the outside by use of the first key, movement of the outside deadlock latch 45 from the position shown in Figure 9 will be prevented by engagement of the first leg 53 with the outside deadlock latch 45. Thus the pin will not leave the curved notch 52 on the bolt 20 and the door cannot be opened. This position is shown in Figure 12.

If, however, the second key is used to open the door from the outside then both the outside and inside cams 41, 42 will be rotated together. Because the lower edge 49 of the outside deadlock latch 45 is above the lower edge 50 of the inside deadlock latch 46 the inside cam 42 will contact the lower edge 50 before the outside cam 41 contacts its associated lower edge 49. Thus the inside deadlock latch 46 will begin to rotate about its pivot before outside deadlock latch 45 and relative movement between the two deadlock latches 45,46 will be allowed by the lost motion provided by movement of the pin 47 in the slot 48.This movement of the inside deadlock latch 46 will move the second leg 54 of the restriction latch 53 thus rotating the shaft of the restriction latch and moving the first leg 54 out of the position shown in Figure 12 in which it prevents rotation of the outside deadlock latch 45.

Continued rotation of both the cams 41,42 will cause both deadlock latches 45, 46 to rotate together as the pin 47 reaches the bottom of the slot 48. The shaft of the restriction latch will continue to rotate and the pin 47 will be lifted out of the curved notch 52 in the bolt. The cams 41,42 will then engage in the cut-out portion 47 in the bolt 20 to retract the bolt from the keep aperture 19. This position is shown in Figure 13. As the door is opened, the locking member 21 extends from the lockcase 23 to move the peg 31 of the release latch 32 into engagement with the further notch 30 on the bolt 20; thus retaining the bolt 20 in the retracted position.

If the knob 44 is turned from the inside of the room with the restriction latch 53 set as shown in Figure 12, the outside cam 42 will contact the lower edge 50 of the inside deadlock latch 46 to lift the deadlock latch 46 and reset the restriction latch as described above. Continued turning of the knob will also remove the pin 47 from engagement with the bolt 20 and retract the bolt 20 as described above.

As shown in Figures 12 and 13, the leg 55 of the restriction latch 53 may be provided with a springloaded ball 57 which locates in a hole 58 (see Figure 12) in the lockcase 23 when the restriction latch 53 is in its inoperative position. This provides positive operation of the restriction latch 53 and prevents unwanted operation of the latch.

The deadlock described above with reference to Figures 9 to 13, is particularly useful in hotels.

Guests can be provided with the first key while the management can retain the second key for emergency use only. The restriction cam provides additional security for a hotel guest using the room and will prevent entry even to persons holding the correct first key. An indication can be given externally on the door either by a rotating disc or projecting pin to show that the occupant does not wish to be disturbed.

The normal extra feature commonly used in standard locked cases such as micro switches or alarm circuits can be incorporated in the automatic deadlock design.

It will be appreciated that the distance moved by the locking member 21 on closure of the door should exceed a certain minimum to cause sufficient movement of the release latch 32 to release the bolt 20. In certain cases, the gap between the door edge and the keep 18 may be so great that this movement is not obtained. To allow for this, the locking member 21 may be movable axially relatively to the rod which connects the member 21 to the limb of the release latch 32. This movement may be achieved by the provision of a screw accessible through an aperture in the part of the locking member 21 outside the locking case.

It will also be appreciated that the locking member 21 shown in the accompanying drawings may be replaced buy a ball.

Claims (22)

1. An automatic deadlock comprising a bolt urged by a spring into a keep-engaging position, a deadlock latch movable into and out of a bolt engaging position occupied by the deadlock latch when the bolt is in the keep-engaging position to prevent forced retraction of the bolt, the bolt being retracted to compress the spring and the deadlock latch leaving the bolt-engaging position on operation of a manually operable member and being held in a retracted position by a release latch, a locking member projecting from the deadlock when the bolt is in the retracted position and being movable to disengage the release latch from the bolt, the bolt then moving under the action of the compressed spring to the keep-engaging position where the bolt is re-engaged by the deadlock latch.

2. An automatic deadlock according to claim 1 wherein the release latch comprises a pivotally mounted member which is urged by a spring towards the bolt-engaging position, retraction of the locking member from the position in which the locking member projects from the deadlock pivoting the member against the action of the spring to allow retraction of the bolt.

3. An automatic deadlock according to claim 2 wherein the pivotally mounted member comprises a bell crank which has a peg formed at one end which latches in a co-operating notch in the bolt when the bolt is in the retracted position and which is connected at its other end to the locking member for pivotal movement thereby upon movement of the locking member to disengage the tooth from the bolt.

4. An automatic deadlock according to any one of claims 1 to 3 wherein locking member is urged by a spring into the position in which the locking member projects from the deadlock, the spring also urging the release latch into engagement with the bolt.

5. An automatic deadlock according to any one of claims 1 to 4wherein the deadlock latch includes a tooth which engages in a co-operating notch in the bolt, when the bolt is in the keep-engaging position, operation of the manually operable member removing the projection from said depression.

6. An automatic deadlock according to claim 5 wherein the deadlock latch is urged into the boltengaging position by a spring, operation of the manually operable member lifting the deadlock latch against the action of the spring.

7. An automatic deadlock according to any one of claims 1 to 6 wherein the deadlock latch is pivoted for movement into and out of the bolt-engaging position.

8. An automatic deadlock according to any one of claims 1 to 7 wherein the manually operable member includes a cam rotatable on operation of the manually operable member, said cam, on rotation, engaging the bolt to retract the bolt.

9. An automatic deadlock according to claim 8 when dependent on claim 7 wherein, on rotation, the cam engages the deadlock latch to pivot the deadlock latch out of said bolt-engaging position before retracting the bolt.

10. An automatic deadlock according to claim 8 or claim 9 wherein the cam is rotatable from one side only of the deadlock.

11. An automatic deadlock according to claim 8 or claim 9 wherein the cam is rotatable from either side of the deadlock.

12. An automatic deadlock according to claim 10 or claim 11 wherein the manually operable member includes a key operated lock provided on at least one side of the deadlock for rotation of the cam by use of a key.

13. An automatic deadlock according to claim 12 when dependent on claim 11 wherein the manually operable member includes a handle provided on the other side of the deadlock for rotation of the cam, said handle being in addition to or as an alternative to a key operated lock.

14. An automatic deadlock according to any one of claims 1 to 13 wherein the deadlock latch is one or two such deadlock latches, both latches engaging the bolt when the bolt is in the keep-engaging position, the manually operable member, in one mode, being operable from one side of the lock to retract the bolt and to move one deadlock latch from the bolt-engaging position and operable from the other side of the lock to retract the bolt and to move the other deadlock latch from the bolt-engaging position, the two deadlock latches being so interconnected that movement of one deadlock latch from the bolt-engaging position causes corresponding movement of the other deadlock latch.

15. An automatic deadlock according to claim 14 and further comprising a restriction latch movable manually from one side of the lock into and out of a locking position in which that deadlock latch which is moved on operation of the manually operable member in said one mode from the side of the lock opposite to the locking member is prevented from leaving said bolt engaging position on said operation ofthe manually operable member in said one mode from said opposite side of the deadlock, thereby maintaining the bolt in the keep-engaging position.

16. An automatic deadlock according to claim 15 wherein said restriction latch is movable out of the locking position by operation of the manually operable member in a second mode from said opposite side of the deadlock, said second mode of operation causing the manually operable member to move both the first-mentioned and the second deadlock latches out of their bolt engaging positions, the second deadlock latch being so arranged as to be moved by the manually operable member before the first-mentioned deadlock latch, the connection between the first-mentioned and second deadlock latches including lost motion which allows the second deadlock latch to move initially independently of the second deadlock latch, said initial movement moving the restriction latch from the locking position, the first-mentioned and second latches then moving together to leave their bolt engaging positions, thus allowing retraction of the bolt by the continued operation of the manually operable member.

17. A automatic deadlock according to claim 16 wherein the restriction latch comprises a member having two legs, said legs being manually rotatable into and out ofthe locking position in which one leg prevents movement of the first-mentioned deadlock latch out of the bolt engaging position, the other leg, in the locking position, being so arranged that said other leg is engaged and moved by the second deadlock latch on movement of the second deadlock latch by operation of the manually operable member in the second mode, said movement of the second leg rotating the member to move the first leg out of the locking position.

18. An automatic deadlock according to any one of claims 14to 17 wherein the manually operated member includes two cams, one cam alone being rotated on operation of the manually operable member from one side of the deadlock in the said one mode, the cam during said rotation moving the first-mentioned deadlock latch from the bolt engaging position and retracting the bolt, the other cam alone being rotated on operation ofthe manually operable member from the other side of the deadlock in said one mode, the other cam during said rotation moving the second deadlock latch from the bolt engaging position and retracting the bolt, operation of the manually operable member from said one side in the second mode rotating both cams together.

19. An automatic deadlock according to claim 18 wherein the manually operable member includes a key operated lock in said one side of the deadlock for rotation of said one cam by use of the key.

20. An automatic deadlock according to claim 18 or claim 19 wherein the manually operable member includes either a key operated lock or handle on said other side of the deadlock for rotation of the other cam either by use of the key or by rotation of the handle.

21. An automatic deadlock according to any one of claims 1 to 20 wherein the extent to which the locking member projects for the deadlock is adjustable by adjusting means accessible from the outside of the deadlock.

22. An automatic deadlock substantially as hereinbefore described within reference to and as shown in Figures 1 to 6 orto Figures 1 to 6 as modified by Figures 7 and 8 orto Figures 9 to 13 of the accompanying drawings.