GB2134963A

GB2134963A - Latch with deadlock

Info

Publication number: GB2134963A
Application number: GB08303420A
Authority: GB
Inventors: Jeffrey Alan Moore
Original assignee: Pickersgill-Kaye Ltd; Pickersgill Kaye Ltd
Current assignee: Pickersgill-Kaye Ltd; Pickersgill Kaye Ltd
Priority date: 1983-02-08
Filing date: 1983-02-08
Publication date: 1984-08-22
Also published as: GB8303420D0; GB2134963B

Abstract

A latch deadlock which from the outside can only be unlocked when a remotely controlled signal is sent to the deadlock, but which can be unlocked from the inside at any time. The lock mechanism is mounted in a door and a striker plate is mounted in a doorway, for example, so as to engage a bolt 3 when the door is locked. When the signal is sent a solenoid 14 moves via 15 a deadlock lever 4 out of engagement with the bolt 3, and by turning an outside handle at 12 the bolt can be withdrawn from the striker plate, so unlocking the door. When no signal is sent, the deadlock lever prevents movement of the bolt via the outside handle at 12. By turning an inside handle at 13, the deadlock lever 4 can be moved out of engagement and the bolt withdrawn, whether or not the signal is sent. A microswitch 16 can be used to detect the position of the bolt, to determine whether the lock is locked or unlocked. <IMAGE>

Description

SPECIFICATION Latch deadlock The present invention relates to a latch deadlock.

There is a need for a latch deadlock for use for instance on the door of premises which must be highly secure. That is, in a situation in which entry to premises must be strictly monitored and controlled there is a need for latch deadlock which can be unlocked by a person wishing to gain entry to the premises only when entry is authorised from within the premises. When entry is not authorised from within the premises the deadlock should not be unlockable by a person wishing to gain entry.

It is desirable that such a deadlock should be unlockable to allow exit from the premises without the need for authorisation, in case of emergency.

It is further desirable that an indication should be given whenever the deadlock is unlocked, for monitoring of persons entering and leaving the premises.

According to the present invention there is provided a latch deadlock comprising: a bolt slidably fitted in the lock with a striker part for engaging in an aperture of a striker plate when the lock is in a locked condition, a handle follower for engaging the bolt and rotatable for slidably withdrawing the bolt to withdraw the striker part from such striker plate, a ram, slidably mounted on the bolt with a channel therefor in the striker part, one end arranged to bear against such striker plate when the lock is in the locked condition so that the ram is withdrawn into the lock in that condition, a deadlock lever arranged to cooperate with the ram and the bolt such that when the ram is withdrawn into the lock the deadlock lever normally engages with the bolt to prevent withdrawal of the bolt by rotation of the handle follower, a solenoid, electrically remotely operable, mechanically linked with the deadlock lever so that when the solenoid is operated the deadlock lever is freed from normal engagement with the bolt to permit withdrawal of the bolt by rotation of the handle follower.

The deadlock may be provided with a microswitch, arranged to cooperate with the holt, for giving an indication when the bolt is withdrawn.

The deadlock may have a further handle follower, arranged to engage with the bolt and rotatable for slidably withdrawing the bolt to withdraw the striker part from such striker plate, and arranged to engage with the deadlock lever and rotatable to free the deadlock lever from normal engagement with the bolt to permit withdrawal of the bolt by the rotation of the further handle follower.

Reference is made, by way of example, to the accompanying drawings, in which: Figure 1 is a schematic plan view of a latch deadlock embodying the present invention, in a "locked" condition, with a cap part of the casing of the deadlock removed.

Figure 2 is a partial plan view of the deadlock of Figure 1, in an "unlocked" condition.

Figure 3 is a plan view of the bolt of the deadlock, Figure 4 is a perspective view of a ram of the deadlock, Figure 5 is a perspective view showing parts of the bolt and ram which can project from the lock casing, Figure 6 is a perspective view of a deadlock lever of the deadlock, Figure 7 is a perspective view of a pivot slide block of the deadlock, Figure 8 is a perspective view of a deadlock release handle follower of the deadlock, Figure 9 is a perspective view of an outside handle follower of the deadlock, Figure 10 is a perspective view of a solenoid release slide of the deadlock, Figure 11 is a plan view of a striker plate for the deadlock, Figure 12 shows perspective views of alternative possible forms of deadlock lever for the deadlock, Figure 1 3 is a perspective view showing parts of the bolt and ram which can project from the lock casing in a left hand lock embodying the present invention, and Figure 14 is a perspective view of the ram of such a left hand lock.

The illustrated lock embodying the present invention has a casing 1. A cap part of the casing, which fits over the internal parts of the lock as seen in Figure 1, is not shown. The lock has a forend 2 with a faceplate 2A which is fitted flush with the edge of a door in which the lock is mounted.

The lock mechanism comprises a bolt 3, slidably fitted in the lock a deadlock lever 4, a deadlock lever spring 5 on a mounting pillar 6, a ram 7, a pivot slide block 8, a spring mounting pin 9, a deadlock adjusting spring 10, a deadlock spring 11, an outside handle follower 12, a deadlock release handle follower 13, a solenoid 14, a deadlock release slide 15, a microswitch 16, and pillars 17, 18 and 19.

The lock, mounted in a door, operates in cooperation with a striker plate 20 as shown in Figure 11, which is fitted to the door frame.

The bolt 3 is urged to the left in Figure 1 by a bolt return spring 3A fitted on a mounting pin 3B fixed to the casing 1 and located in a bore in the bolt 3.

In the plan view of Figure 3 cross-hatched parts are at a level raised above that of the parts shaded with diagonal lines.

A striker part 3C of the bolt 3 normally projects beyond the face plate 2A, to engage with the striker plate 20. The striker part 3C has a channel 3D for the ram 7, as shown in the perspective view of Figure 5. The bolt has a face 3E for engaging the deadlock release handle follower 13, a projection 3F for engaging the outside handle follower 12, and a projection 3G for guiding the ram 7. An aperture 3H is formed in the bolt 3 for accommodating the spring mounting pin 9, springs 10 and 1 and parts of the ram 7 and pivot slide block 8. To the right of a line 31 in Figure 3 the bolt 3 is undercut to allow the bolt to move rightwards in Figure 1 over the deadlock release slide 15.

The deadlock lever 4, has, as shown in Figure 6, a face 4A for engaging the bolt 3, a part 4B for engaging the deadlock release handle follower 13, a face 4C for engaging the deadlock lever spring 5, a face 4D for engaging the deadlock release slide 15, a hole 4E therethrough for a mounting pin 4F which pivotally mounts the deadlock lever 4 on the pivot slide block 8.

The deadlock lever spring 5, coiled around mounting pillar 6, has a short arm 5A which engages the casing 1 and a long arm 5B which engages with face 4C of deadlock lever 4, to urge the lever 4 clockwise (as seen in Figure 1), around the mounting pin 4F.

The ram 7, which fits in the channel 3D of the bolt 3, has at its end inward of the lock a projection 7A which is accommodated in the aperture 3H of the bolt 3. The projection 7A has a bore 7B therethrough for the spring mounting pin 9.

The pivot slide block 8 is generally L-shaped.

One arm 8A of the L-shape is accommodated within the aperture 3H of the bolt 3. In that arm a bore 8B is formed for the spring mounting pin 9.

The other arm of the L-shape has an aperture 8C for receiving the mounting pin 4F.

The spring pin 9 is mounted lengthwise along the aperture 3H in bolt 3, passing through the bores 7B and 8B of ram 7 and pivot slide block 8.

The deadlock adjusting spring 10 is mounted on the pin 9 between the ram 7 and the pivot slide block 8, whilst the deadlock spring 11 is mounted on pin 9 between the pivot slide block 8 and the right hand end, as seen in Figure 3, of the aperture 3H.

The outside handle follower 12 has a projection 1 2A for engaging the projection 3F on the bolt 3, and a projection 1 2B for engaging the pillar 17, which acts as a stop. 12C is a rectangular bore for a handle-carrying shaft.

The deadlock release handle follower 13 is so formed as to provide a bolt engaging face 1 3A, for engaging face 3E of bolt 3, a deadlock lever engaging part 1 3B, for engaging part 4B of the deadlock lever 4, and a projection 1 3C for engaging pillar 18, which acts as a stop. 1 3D is a rectangular bore for a handle carrying shaft.

The solenoid 14 has a movable pin 1 4A, which is urged upwardly, as seen in Figure 1, when the solenoid is operated. The solenoid is mounted on a bracket 1 4B fixed to the casing 1. Cables 14C from the solenoid pass through an aperture provided in the casing 1.

The deadlock release slide 15 is formed as a plate with a bent up tongue 1 5A at one end for engaging the solenoid pin 14A. The other end of the slide 1 5 engages with face 4D of the deadlock lever 4.

A projection 15B on the casing 1, a pin 15C through the casing 1, and a tongue 15D on the casing 1 all serve to guide the slide 1 5.

The microswitch 1 6 is so arranged as to be 'closed' when the bolt 3 is positioned as shown in Figure 1, and 'open' when the bolt is withdrawn (rightwardly in Figure 1) into the lock casing 1.

Insuiation 1 6A is provided on the lock casing, and cables 1 6B from the microswitch pass out of the casing with the cables of the solenoid, in the illustrated embodiment.

Pillars 17, 18 and 6 provide threaded holes for bolts or screws for fixing the cap part of the casing.

The striker plate 20 has an aperture 20A for receiving the bolt. A part 20B of the striker plate engages the end of the ram 7 seen in Figure 5.

Mounted in a door the lock is fitted with inside and outside handles mounted on shafts fitted respectively in the bores 1 3D and 12C in the deadlock release handle follower 13 and the outside handle follower 12.

With the door closed and the inside and outside handles unturned the normal disposition of the lock is as shown in Figure 1. The bolt part 3C projects beyond the face plate 2A and engages with the striker plate 20 arranged to cooperate with the lock. The part 3C passes into striker plate aperture 20A whilst the end of the ram abuts against striker plate part 20B.

The deadlock lever 4, urged by the long arm 5A of spring 5 bearing on its face 4C, is in the position shown in Figure 1, so that its boltengaging face 4A bears on the rightmost end of the bolt 3 (as seen in Figure 1).

The part 4B of deadlock lever 4 is dropped behind the deadlock lever engaging part 1 3B of the deadlock release handle follower 13, whose projection 13C abuts the pillar 1 8.

The springs 10 and 11 are compressed on the spring pin 9. The pivot slide block 8 is relatively rearward (rightward in Figure 1) of the bolt.

The outside handle follower 12 has its projections 1 2A and 1 2B bearing on the projection 3F of the bolt 3 and on the pillar 17 respectively.

In this disposition, if the outside handle is turned, the projection 1 2A on the outside handle follower 12 rotates slightly clockwise and the bolt 3 is moved slightly rightward (as seen in Figure 1) by the force exercised on the projection 3F.

However as the bolt 3 moves rightwardly the deadlock lever 4 is carried rightwardly also and is jammed between the bolt 3 and the casing 1:- the bolt-engaging face 4A bears on the right-most end of the bolt 3 whilst the rightmost end of the deadlock lever 4 bears on the casing 1. The bolt part 3C can thus be only partly retracted into the casing 1 and the lock cannot be opened.

However, if, before the outside handle is turned, the solenoid 14 is actuated, the solenoid pin 1 4A moves upwards (as seen in Figure 1) acting on the bent-up tongue 15A to urge the deadlock release slide 1 5 upwards into engagement with face 4D of the deadlock lever 4 which is in turn moved upwards (and rotated counterclockwise around pin 4F) to a dispositon in which the face 4A no longer engages the bolt 3. Thus, the deadlock lever 4 is lifted clear of the bolt 3 and by turning the outside handle the bolt 3 can be moved fully rightward into the casing 1, with the ram 7 and the pivot slide block 8 remaining substantially stationary, sliding on the spring pin 9 as the bolt 3 moves rightwardly.

With the bolt 3 in a fully rightward position the microswitch 1 6 is 'open' and a signal indicating that the lock has been opened is given through the cables 16B.

The door can now be swung open, with the bolt 3 withdrawn from the striker plate 20.

With the door open and the outside handle released the bolt 3 is returned under the urging of spring 3A and, because there is no engagement with the striker plate 20, the ram 7 moves leftward (as seen in Figure 1), to emerge from the lock casing 2, together with the pivot slide block 8, which carries with it the deadlock lever 4, under the urging of spring 11.

The disposition shown in Figure 2 is thereby achieved.

With the solenoid 14 deactuated the pin 14A and slide plate 15 return to their disposition as shown in Figure 1.

As the door is closed, the bolt 3 strikes the striker plate 20, and is forced rightward, as is the ram 7 together with the pivot slide block 8 and the deadlock lever 4. As the bolt 3 engages the striker plate aperture 20A, the bolt 3 moves leftward (part 3C fitting into the aperture 20A) under the force of spring 3A, but the ram 7 is held by part 90B. The slide block 8 and deadlock lever 4 are also held, and as the bolt 3 moves leftward the face 4A of the deadlock lever clears the rightward end of the bolt 3. The deadlock lever 4 drops down under force of spring 5 with face 4A behind the rightward end of the bolt and the part 4B behind projection 1 3B.

Thus, the disposition of Figure 1 is restored.

The microswitch 1 6 returns to the 'closed' position.

The inside handle, mounted on a shaft in bore 1 3D of the deadlock release handle follower 13, can be used to open the lock without actuation of the solenoid 14.

When the inside handle is turned the face 1 3A of the follower 13 engages the face 3E of the bolt 3 to urge the bolt rearwardly, and the projection 1 3B engages the projection 4B on the deadlock lever 4 lifting and turning the deadlock lever to lift the face 4A clear of the rightward end of the bolt 3. Thus, the bolt 3 can be moved rightwardly to open the lock.

When the door is opened and the outside handle released the lock attains the disposition shown in Figure 2, and operation as the door is closed is as described above.

It will be understood that the lock can be opened by means of the outside handle only when authorisation is given by actuation of the solenoid 14. Otherwise, the lock cannot be opened by the outside handle. On the other hand, the lock can be opened by the inside handle, without authorisation by actuation of the solenoid.

Indication of opening is given by the microswitch 1 6.

There may be situations in which opening by inside handle without authorisation is not required. In such event the deadlock release handle follower may be omitted (together with cooperating parts on the bolt and deadlock lever) and both inside and outside handles fitted to a shaft through the outside handle follower.

Figure 12 shows alterantive forms of deadlock lever 4. In each of the alternative forms the face 4C, on which the long arm 5B of spring 5 bears, is of greater extent than in the lever form shown in Figure 6. The greater extent of face 4C avoids the possibility, for example in very cold conditions, of the end of spring arm 5B falling from the face 4C to bear on the face 4A and thus jamming the lock.

The lock illustrated in Figures 1 to 12 is a right hand lock. In a left hand lock the mechanism is the same except for the ram 7 and the striker part 3C of bolt 3. The dispositions of ram 7 and striker part 3C in a left hand lock are shown in Figure 13 (compare Figure 5), and a raln 7 for a left hand lock is shown in Figure 14 (compare Figure 4). The bore 7B in the left hand ram is filled on the spring mounting pin 9. Although the striker part 3C of the bolt of a left hand lock differs from the form shown in Figure 3, those parts of the bolt which remain at all times within the lock casing are unchanged. The aperture 3H has a wider part 3J which enables the left hand ram to be fitted.

The deadlock adjustment spring 10, between ram 7 and pivot slide block (in both left hand and right hand locks) is provided so that any gap between faceplate 2A and striker plate 20 (when the door is closed) can be taken up.

The present invention provides a latch deadlock which can be unlocked by a person wishing to gain entry to a premises only when entry is authorised by activation of the solenoid 14. Normally solenoid actuation will be provided from within the premises but it is possible for actuation of the solenoid 14 to be provided by means of a key switch or combination switch outside the premises. Of course, if solenoid actuation can be provided from outside the premises, by means of the key switch or combination switch, it can be given only by an authorised key or combination holder.

Claims

1. A latch deadlock comprising: a bolt slidably fitted in the lock with a striker part for engaging in an aperture of a striker plate when the lock is in a locked condition, a handle follower for engaging the bolt and rotatable for slidably withdrawing the bolt to withdraw the striker part from such striker plate, a ram, slidably mounted on the bolt with a channel therefor in the striker part, one end arranged to bear against such striker plate when the lock is in the locked condition so that the ram is withdrawn into the lock in that condition, a deadlock lever arranged to cooperate with the ram and the bolt such that when the ram is withdrawn into the lock the deadlock lever normally engages with the bolt to prevent withdrawal of the bolt by rotation of the handle follower, a solenoid, electrically remotely operable, mechanically linked with the deadlock lever so that when the solenoid is operated the deadlock lever is freed from normal engagement with the bolt to permit withdrawal of the bolt by rotation of the handle follower.

2. A latch deadlock as claimed in claim 1, provided with a microswitch, arranged to cooperate with the bolt, for giving an indication when the bolt is withdrawn.

3. A latch deadlock as claimed in claim 1 or 2, further comprising a further handle follower, arranged to engage with the bolt and rotatable for slideably withdrawing the bolt to withdraw the striker part from such striker plate, and arranged to engage with the deadlock lever and rotatable to free the deadlock lever from normal engagement with the bolt to permit withdrawal of the bolt by the rotation of the further handle follower.

4. A latch deadlock as cliamed in claim 1,2 or 3, wherein the deadlock lever has a portion which locates behind the bolt with a face which engages the rear of the bolt, to prevent withdrawal of the bolt, in normal engagement with the bolt.

5. A latch deadlock as claimed in claim 4, further comprising a deadlock release slide disposed between the solenoid and the said portion of the deadlock lever, slidable when the solenoid is operated to displace to said portion from location behind the bolt to free the deadlock lever from normal engagement with the bolt.

6. A latch deadlock as claimed in claim 4 or 5, wherein the deadlock lever is pivotally mounted on a pivot slide block, behind the ram in the lock, the block and the ram each being slidable along a pin mounted on the bolt with a resiliently compressible spring on the pin between the block and the ram, so that when the ram is withdrawn into the lock the block is urged rearwardly of the lock to permit the said portion of the deadlock lever to locate behind the bolt, and when the ram is not so withdrawn, the block is forwardly disposed in the lock and the said portion of the deadlock lever cannot locate behind the bolt.

7. A latch deadlock as claimed in claim 6, having a further resiliently compressible spring on the pin behind the block, for urging the block forwardly of the lock.

8. A latch deadlock as claimed in any preceding claim, further comprising a resiliently compressible bolt return spring arranged to urge the bolt forwardly of the lock.

9. A latch deadlock substantially as hereinbefore described with reference to Figs. 1 to 11, and/or as modified by Figures 13 and 14, and/or as modified by Figure 12, of the accompanying drawings.