GB1598066A - Sliding latch door fasteners - Google Patents

Description

(54) IMPROVEMENTS IN SLIDING LATCH DOOR FASTENERS (71) We, WEST ALLOY DIECASTINGS LIMITED, a British Company of Garth Road, Morden, Surrey, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to an improved sliding latch door fastener and more particularly to a so-called quick release lock in which the sliding latch bolt can be deadlocked by operation of a snibbing means from inside the door or by operation of a key actuated barrel lock mechanism from outside the door, the thus deadlocked bolt being releasable quickly and automatically by a normal rotary motion imparted to the interior lever handle or by operation of the barrel lock mechanism from outside the door.

An object of this invention is to provide a lock wherein by a further action, when the latch is deadlocked, the key actuated lock mechanism and the exterior handle are both isolated from the lock mechanism and rendered inoperative.

According to this invention there is provided lock with a casing housing a sliding latch bolt and an interior handle and an exterior handle both being capable of effecting withdrawal of the bolt, a snibbing means operable to deadlock the bolt against retraction with the snibbing means being released on operation of the interior handle or by an exterior mounted key operated mechanism to allow withdrawal of the bolt, operation of the snibbing means also effecting disengagement of the exterior mounted handle, the casing further including isolating means whereby the key operated mechanism may be operatively disengaged to prevent release of the snibbing means thereby.

A characteristic of this invention is the provision of the isolating means enabling entry, by means of a key, to be prevented if required. Preferably the isolating means is formed by a slot in the casing into which the nose of a key, e.g. the lock key, or other member can be inserted to displace a latch operating member so that it lies out of range of the movement of a lock barrel actuating part which is part of the key operated mechanism.

In one construction the latch bolt includes a cam plate pivoted thereto and engageable by dogs associated with the interior handle whereby rotation thereof causes withdrawal of the bolt, the plate having a recess normally engaged by a projecting part of the exterior handle, operation of which also effects withdrawal of the bolt.A snibbing means mounted to the casing is coupled to pivot the cam plate to a deadlocked position in which retraction of the bolt is prevented by an abutment and in which the projecting part of the exterior handle lies in a slotted extension of the recess whereby on operation, said handle does not operatively engage the cam plate, the cam plate being pivotable back to the normal position on rotation of the interior handle A key actuated lock barrel has a tongue and rotation of the barrel causes the tongue to co-act with respective abutment surfaces on the cam plate either to move the plate into the deadlocked condition or to release the plate from such a condition.

With this construction when the bolt is deadlocked, the key barrel tongue may be readily operatively disengaged from the cam plate by providing a slot in the casing and a co-aligned slot in the cam plate normally displaced laterally slightly whereby insertion of a flat member, such as the nose of the lock key, causes the cam plate to be laterally displaced. This moves the abutment surfaces of the cam plate out of range of the tongue of the lock barrel.

A construction of lock in accordance with the invention is described way of an example with reference to the drawings accompanying the Provisional Specification. In the drawings: Figures 1 to 4 show the principal operative parts of a lock mechanism viewed from inside a door, and in four different states of operation, and Figure 5 is a section on X-X of Figure 1 of a complete lock.

Reference firstly is made to Figures 1 and 5 which show the lock in the "unlocked" condition with the inside handle 1 just commencing withdrawal of the latch bolt 2.

The lock is adapted for through-mounting in an aperture A of a door D and has a casing 3 for mounting towards the inside of the door with a flange 4 engaging the exterior surface of the door. A surface plate 5 has a flange 6 which bars against the inside surface of the door and carries the handle 1 rotatably mounted there-on. The casing 3 and plate 5 are secured together by screws at 7. The exterior face of the casing 3 includes a recess 8 with a flap-handle 9 pivoted at 10 and carrying a projecting latch actuating member 11 which can engage an abutment surface 12 of a cam plate 13 to cause the bolt 2 to be withdrawn inwardly of the casing by virtue of a pivotal connection 14 between the cam plate and bolt.Withdrawal of the bolt can also be effected by turning the handle 1 with a downward or upward movement which causes a dog 15 formed as a projection on a boss 16 engaged by the handle spigot 17, to abut surface 18 of the cam plate 13.

The boss 16 includes a spring 19 lying in a torus 20 with ends in abutment with a lug 21 to effect restoration of the handle to a horizontal position after turning in either direction.

The tail end lip 13a of the cam plate is guided by a rod 22 passing through aperture 23 in the lip. The rod has a curved end 24 received in a socket 25 of the casing. A spring 26 urges the cam plate and hence bolt 2 outward.

A key actuated lock barrel 27 is housed in the casing and has a tongue 28 which is able to engage a recess 29 in the cam plate on rotation of the key to effect movement of the cam plate as hereinafter described.

A snibbing means (not shown) and comprising a rocker pivotally mounted on the plate 5 and located in a recess therein is arranged to co-act with a stub 30 of the rod end 24.

In Figure 2 the bolt 2 is shown fully withdrawn; this position having been achieved by continued rotation of handle 1 in an anticlockwise direction and action of dog 15 on the surface 18 of the cam plate 13.

Spring 26 is compressed. This bolt withdrawal could have been effected also by operation of the flap handle 9 causing the actuating member 11 to move the cam plate via the surface 12 provided the mechanism is in the unlocked position at the start.

In Figure 3 the bolt 2 is deadlocked but allows a small horizontal movement with the cam plate 13 turned about pivot 14 in a clockwise direction either by the tongue 28 of the lock barrel engaging recess 29 on clockwise rotation or by the rocker moving the stub 30 to the left. The bolt cannot be fully retracted by a thrust applied directly thereto due to abutment with a shoulder 31 after initial movement and the over-centre action of the rod 22 and spring 26. The deadlocked condition is released by rotation of the handle 1 causing dog 15 to first turn the cam plate about pivot 14 by abutment against surface 18 and thereafter causing withdrawal of the bolt.

A further dog 15' effects withdrawal of the bolt and also release from the deadlocked condition by rotation of the handle 1 in the opposite direction and abutment with surface 18' causing the cam plate to turn about pivot 14 and thereafter to move to withdraw the bolt. Thus release from the deadlock state and opening of a door is achieved by operation of the handle in either direction.

The exterior handle 9 is isolated from the lock mechanism when deadlocked by virtue of the actuating member 11 lying in a slotted part 32 of the cam plate.

The deadlocked state is also released by reverse rotation of the lock barrel tongue 28 which engages a recess 29 to turn the cam plate.

Figure 4 shows the fully isolated condition which follows from the deadlocked state of Figure 3. A slot 33 is provided in the cam plate with an aligned co-acting slot 34 in the casing. By insertion of a tapered strip member through an aperture in the plate 5, the cam plate 13 is moved backwards to fully align slots 33 and 34. The tongue 28 of the lock barrel cannot now release the cam plate as the recess 29 is out of range and the cam plate is secured against rotation by abutment with the shoulder 31 by the strip member.

To obtain the condition shown in Figure 4 a cam or other means could be used.

A restrictor plate 36 prevents the barrel lock 27 from overturning whilst in the condition of Figure 3 or the unlocked conditions of Figures 1 and 2, but allows unrestricted rotary movement of the barrel-lock to take place when the mechanism is in the deadlocked and fully isolated condition of Figure 4. This prevents an intruder or vandal from wilfully damaging the cam mechanism by forcing and turning the barrel lock.

The restrictor plate 36 is directly controlled by the cam plate 13 through a raised pip 37 sliding in a shaped channel 38. When the mechanism is in the Figure 3 condition the pip 37 is at the start of the angled portion of the channel 38 positioning the plate face 39 within the sweeping area of the barrellock tongue 28 preventing clockwise move ment of the barrel-lock.

When the latch bolt 2 moves inwards changing the mechanism to the Figure 4 condition, the raised pip 37 also moves in a horizontal inward direction moving the restrictor plate 36 via the channel 38 transversely so that face 39 moves away from the sweeping area of the barrel lock tongue 28.

The remaining part of the channel allows further horizontal movement of the raised pip to take place, when the lock is fully withdrawn as in Figure 2.

The lock has the following features:- (1) Free Entry and Exit Door secured but unlocked, allowing entry and exit by the operation of a knob, lever or flap handle, as with conventional locking mechanism.

(2) Quick-release Locking from the exterior by the use of a key-operated barrel-lock mechanism or from the interior via a catch, placing the latch bolt in a deadlocked state and isolating the exterior mounted knob, lever or flap handle from the internal locking mechanism. Unlocking is effected from the exterior by the use of a key-operated barrel-lock mechanism or automatically from the interior by the normal operation of the interior mounted knob, lever or flap handle.

(3) Night Security In addition to the condition given in above complete isolation of the key-operated barrel-lock mechanism from the internal locking mechanism is achieved by the internal insertion of a key nose, rod or similar device, or alternatively, by the operation of an internally mounted catch.

Contact of the key-operated barrel-lock mechanism with the internal locking mechanism can again be made by the reverse procedure, i.e. extracting the key, rod or similar device or alternatively by the reverse operation of the internally mounted catch.

WHAT WE CLAIM IS: 1. A lock with a casing housing a sliding latch bolt and an interior handle and an exterior handle both being capable of effecting withdrawal of the bolt, a snibbing means operable to deadlock the bolt against retraction with the snibbing means being released on operation of the interior handle or by an exterior mounted key operated mechanism to allow withdrawal of the bolt, operation of the snibbing means also effecting disengagement of the exterior mounted handle, the casing further including isolating means whereby the key operated mechanism may be operative disengaged to prevent release of the snibbing means thereby.

2. A lock in accordance with Claim 1, wherein the isolating means is formed by a slot in the casing into which the nose of a key or other member can be inserted to displace a latch operating member so that it lies out of range of the movement of a lock barrel actuating part which is part of the key operated mechanism.

3. A lock in accordance with Claim 1 or 2, wherein the latch bolt includes a cam plate pivoted thereto and engageable by dogs associated with the interior handle whereby rotation thereof causes withdrawal of the bolt, the plate having a recess normally engaged by a projecting part of the exterior handle, operation of which also effects withdrawal of the bolt.

4. A lock in accordance with Claim 3, wherein a snibbing means mounted to the casing is coupled to pivot the cam plate to a deadlocked position in which retraction of the bolt is prevented by an abutment and in which the projecting part of the exterior handle lies in a slotted extension of the recess whereby on operation, said handle does not operatively engage the cam plate, the cam plate being pivotable back to the normal position on rotation of the interior handle.

5. A lock in accordance with Claim 3 or 4, wherein a key actuated lock barrel has a tongue and rotation of the barrel causes the tongue to co-act with respective abutment surfaces on the cam plate either to move the plate into the deadlocked condition or to release the plate from such a condition.

6. A lock in accordance with Claim 3, 4 or 5, wherein the key barrel tongue may be readily operatively disengaged from the cam plate by providing a slot in the casing and a co-aligned slot in the cam plate normally displaced laterally slightly whereby insertion of a flat member, such as the nose of a key, causes the cam plate to be laterally displaced.

7. A lock constructed and arranged to function substantially as herein described with reference to and as shown in the drawings accompanying the Provisional Specification.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. ment of the barrel-lock. When the latch bolt 2 moves inwards changing the mechanism to the Figure 4 condition, the raised pip 37 also moves in a horizontal inward direction moving the restrictor plate 36 via the channel 38 transversely so that face 39 moves away from the sweeping area of the barrel lock tongue 28. The remaining part of the channel allows further horizontal movement of the raised pip to take place, when the lock is fully withdrawn as in Figure 2. The lock has the following features:- (1) Free Entry and Exit Door secured but unlocked, allowing entry and exit by the operation of a knob, lever or flap handle, as with conventional locking mechanism. (2) Quick-release Locking from the exterior by the use of a key-operated barrel-lock mechanism or from the interior via a catch, placing the latch bolt in a deadlocked state and isolating the exterior mounted knob, lever or flap handle from the internal locking mechanism. Unlocking is effected from the exterior by the use of a key-operated barrel-lock mechanism or automatically from the interior by the normal operation of the interior mounted knob, lever or flap handle. (3) Night Security In addition to the condition given in above complete isolation of the key-operated barrel-lock mechanism from the internal locking mechanism is achieved by the internal insertion of a key nose, rod or similar device, or alternatively, by the operation of an internally mounted catch. Contact of the key-operated barrel-lock mechanism with the internal locking mechanism can again be made by the reverse procedure, i.e. extracting the key, rod or similar device or alternatively by the reverse operation of the internally mounted catch. WHAT WE CLAIM IS:

1. A lock with a casing housing a sliding latch bolt and an interior handle and an exterior handle both being capable of effecting withdrawal of the bolt, a snibbing means operable to deadlock the bolt against retraction with the snibbing means being released on operation of the interior handle or by an exterior mounted key operated mechanism to allow withdrawal of the bolt, operation of the snibbing means also effecting disengagement of the exterior mounted handle, the casing further including isolating means whereby the key operated mechanism may be operative disengaged to prevent release of the snibbing means thereby.

2. A lock in accordance with Claim 1, wherein the isolating means is formed by a slot in the casing into which the nose of a key or other member can be inserted to displace a latch operating member so that it lies out of range of the movement of a lock barrel actuating part which is part of the key operated mechanism.

3. A lock in accordance with Claim 1 or 2, wherein the latch bolt includes a cam plate pivoted thereto and engageable by dogs associated with the interior handle whereby rotation thereof causes withdrawal of the bolt, the plate having a recess normally engaged by a projecting part of the exterior handle, operation of which also effects withdrawal of the bolt.

4. A lock in accordance with Claim 3, wherein a snibbing means mounted to the casing is coupled to pivot the cam plate to a deadlocked position in which retraction of the bolt is prevented by an abutment and in which the projecting part of the exterior handle lies in a slotted extension of the recess whereby on operation, said handle does not operatively engage the cam plate, the cam plate being pivotable back to the normal position on rotation of the interior handle.

5. A lock in accordance with Claim 3 or 4, wherein a key actuated lock barrel has a tongue and rotation of the barrel causes the tongue to co-act with respective abutment surfaces on the cam plate either to move the plate into the deadlocked condition or to release the plate from such a condition.

6. A lock in accordance with Claim 3, 4 or 5, wherein the key barrel tongue may be readily operatively disengaged from the cam plate by providing a slot in the casing and a co-aligned slot in the cam plate normally displaced laterally slightly whereby insertion of a flat member, such as the nose of a key, causes the cam plate to be laterally displaced.

7. A lock constructed and arranged to function substantially as herein described with reference to and as shown in the drawings accompanying the Provisional Specification.