AU4879999A - Improvements in door locks - Google Patents

Description

M M 0 Improvements in locks This invention relates to door locks and more particularly mortise locks for security doors According to the invention, there is provided a lock including a casing, a strike plate, a slidable latch bolt having a leading portion which is displaceable between a retracted position where it is substantially within the casing and a partly extended position and a fully extended position where it protrudes from the casing, biassing means to urge the latch bolt towards the fully extended position, means to restrain the latch bolt from displacing to the *o 00 "fully extended position including an outwardly biased auxiliary bolt operably engageable with the latch bolt and having a leading portion which is displaceable between a retracted position S' and a fully extended position where it protrudes from the casing to cause the latch bolt to be restrained, said auxiliary bolt being displaceable from the fully extended position by strike plate engagement to enable the latch bolt to move to the fully extended position, and operating *means including a hand operable lever to cause the latch bolt to displace towards the retracted position, the leading portion of said latch bolt having both sides similarly curved, ramped or chamfered and said auxiliary bolt having at least a first side curved, ramped or chamfered to facilitate inward displacement of the auxiliary bolt by strike plate engagement with the first side, said first side being selectively disposable and restrainable towards one or other side of the lock.

-2a- There is also provided lock including a casing, a cylinder with a cylinder cam, an angularly displaceable operable auxiliary lever, an engageable means, an engaging member displaceable between a disengaged position and an engageable position in which it is engageable with the engageable means, a biassing means to urge the engaging member towards the engageable position, means to restrain the engaging member from displacing to the engageable position unless the engaging member and engageable means are relatively disposed, deadlocking means including a displaceable deadlocking slide member operably engageable with the engaging member to prevent the engaging member .b from being displaced from the engageable position and operably coupled to the cylinder cam within a first range of cylinder cam movement whereby the deadlocking slide t o• member can be moved by cylinder cam rotation and the cylinder cam can be rotationally displaced by deadlocking member movement and where at a limit of coupled movement Sthe cylinder cam can be further rotated within a second range of cylinder cam movement while the deadlocking slide member remains substantially unmoved restrained by the cylinder cam said second range corresponding with deadlocking of the engaging member by the deadlocking slide member to prevent the engaging member from being displaced from the engageable position, and wherein the auxiliary lever is operably coupled to the deadlocking slide whereby the deadlocking slide is movable in and out of engagement with the latch bolt by rotation of the auxiliary lever only when the actuating cam is within the first range of movement Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a partial schematic cut away side elevation of a lock where the bolt is held partly extended by engagement with the auxiliary bolt, Figure 2 is a partial schematic cut away side elevation of a lock where the bolt is in the fully extended deadlocked position Figure 3 is a partial schematic cut away side elevation of a lock where the deadlocking slide has been adapted to engage a transmission means connected to remote locks Figure 4 is a partial schematic partial enlargement of Figure 3 The invention comprises in summary, a boxlike casing 1, a displaceable latch bolt a displaceable auxiliary bolt 3 positioned adjacent the latch bolt, a deadlocking slide 4 displaceable into engagement with the latch bolt, a pivotally supported rocker member 5 biased towards a cylinder cam, a key operable cylinder S having an angularly displaceable arm 7, an arm S 8 supported within the casing for angular displacement engaged with the deadlocking slide and an operating cam 9 which connects to an external lever by which the main bolt is made to retract Operation of the external lever causes the cam 9 to rotate, and the armed extension 10 of the cam engages the rear shoulder 11 of the latch bolt and draws it inwards thereby causing the latch bolt to retract. The latch bolt in use would be made to retract to a position where it has disengaged a strike plate 57, Fig 2 at which point the door in which the lock is fitted can be opened. Normally the lever would then be slowly released and the cam 9 would angularly displace towards the undisplaced position. As the cam rotates towards the undisplaced position the latch bolt moves slowly under biasing means towards the extended position. It moves outwardly until it is engaged by the auxiliary bolt, at which point the cam continues to displace until it reaches its undisplaced position while the latch bolt is retained at the position of engagement with the auxiliary bolt. In normal use this configuration of the lock occurs just prior to between the opening and closing of a door.

When the door is closed the auxiliary bolt and the latch bolt are depressed inwardly by sliding up the strike plate. When the latch bolt attains the position over the recess in S the strike plate it extends under biasing action towards the fully extended position while the auxiliary bolt is maintained depressed by the strike plate. The latch bolt is able to move outwardly because the depression of the auxiliary bolt causes it to disengage the latch bolt. In the fully extended position, Fig 2 the deadlocking slide can be moved to a position behind the shoulder 12 of the latch bolt thereby preventing the latch bolt from displacing inwardly. This deadlocking slide can be moved by rotation of the arm 7 by a small external lever or by the key operable cylinder.

•Preferably the auxiliary bolt is angled on one side only So that the lock may be used on both the left hand and right hand hinged doors there is means for reversing the auxiliary bolt so that the inclined leading portion 13 can be in the direction of the door closing.

•In more detail the lock comprises a rectangular boxlike casing 1 having a front edge 14 in which there is an aperture 15 through which the latch bolt protrudes and aperture 16 through which the auxiliary bolt protrudes. At each end of the faceplate there are elongated extensions 17 by which the lock casing is secured into a door. The casing also inciudes apertures in the side to accommodate a locking 0 cylinder 6 and spigots 58 with which external levers assemblies are secured. There is also a recess to accommodate a rectangular shaft coupling external levers situated on either side of the door and engaging with the operating cam 9. The operating cam 9 has a substantially cylindrical shape with a rectangular central through hole and an elongated arm 10. The latch bolt 2 has a substantially box shaped profile with a leading end portion having each side curved, chamfered ramped or otherwise profiled to facilitate inward displacement by strike plate engagement on either side. This latch bolt has rearwardly two legs one of which has a rear shoulder 11 which is engageable by the arm 10 of the operating cam. The arm 10 is located in a concave recess that exists between the rear shoulder 11 and the latch bolt leading end. Spring 18 biases the latch bolt outwardly towards the fully extended position, The latch bolt also has a shoulder 12 which is engageable by the deadlocking slide 4 when the deadlocking slide is moved towards the latch bolt. In the deadlocked position the slide lies behind the latch bolt leading end and beside the lower rearwardly projecting leg. Adjacent the auxiliary bolt the latch bolt has at least one ramped projection 19 which projects into the normal path of operation of the rearward shoulder 20 of the auxiliary bolt. The auxiliary bolt comprising a substantially cylindrical portion 21 supported in the recess in the casing faceplate having a rearwardly at least one shoulder 20. This auxiliary bolt has a leading portion that may be curved ramped or chamfered on one or both sides but is preferably chamfered on one side only.

Rearwardly the auxiliary bolt comprises a shaft of rectangular cross section as shown in BB, Fig 2.

This shaft is supported for longitudinal movement and limited vertical movement by the forked extension 22, Fig 2 of the lock casing. Within the

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6 normal range of movement of the auxiliary bolt the shaft of rectangular cross section is supported by the forked extension but between the shaft portion of rectangular cross section and the leading portion of the auxiliary bolt is a portion of circular cross section 23. Depression of the auxiliary bolt beyond the normal range causes this portion 23 to move adjacent the forked support.

When this portion is supported by the forked extension it is possible to rotate the auxiliary bolt so that the inclined portion can be disposed in the direction of door closing to facilitate latching. The auxiliary bolt can be so depressed when the spigot 58 is not within its fitting aperture behind the auxiliary bolt. The auxiliary bolt can be depressed beyond its normal range to be rotated it prior to fitting of the external levers assemblies but it cannot be so depressed when the lock is completely installed because the spigot 58 lies in the path of travel of shoulder 20 to limit its movement.

e On the side of the forked extension furthest from the latch bolt is an inclined surface 24 which is engaged by the auxiliary bolt as the auxiliary bolt is driven outwardly by the

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spring 25 so as to cause the shoulder to move towards the latch bolt as it slides on the inclined S: ".surface. In this way the shoulder moves into a position within the path of normal movement of a *5t leg of the latch bolt thereby being in a position where it is engageable by the latch bolt protrusion 19. Rearwardly of the auxiliary bolt is a casing finned extension 26 that has a ramped leading edge 27 engageable by the shoulder 20 on the auxiliary bolt. When the auxiliary bolt is depressed the i shoulder engages this ramped surface and is caused to deflect away from the latch bolt thereby 555555 moving the engaging shoulder out of an engageable position with the latch bolt The deadlocking slide comprises a blade like plate with a leading edge 28 which is engageable with the latch bolt, a recess 29 engaged by a pin 30 on the pivotally supported arm 8, and a concave recess 31 engagedable with the pivotally supported cam comprising part of 7 the key operable cylinder, said recess 31 having driving shoulders 32 and 33 respectively. Within a first range of movement the cam 7 and the deadlocking slide are coupled whereby translational movement of the deadlocking slide causes the cam 7 to angularly displace while angular displacement of the cam causes the deadlocking slide to displace. Within this first range of movement the deadlocking slide may be actuated by either the arm 8 or the cam 7. At the limit of this first range of movement and corresponding to the deadlocking slide being in the deadlocked position behind the latch bolt the cylinder cam 7 may be displaced in a second range of movement wherein the deadlocking slide remains substantially unmoved and where coupling between the cam 7 and slide 4 ceases so that the deadlocking slide can no longer displace the cam 7 and in effect •displacement of the cam 7 into the second range of movement secures the deadlocking slide in the deadlocking position. When the deadlocking slide has been moved to the deadlocking position a surface on the exit shoulder of recess 31, portion 34, lies substantially orthogonal to the pivot point of the cam 7. At this point the leading edge 35 of cam can be moved to slide on the surface 34 without substantially moving the deadlocking slide.

The pivotally supported rocker 5 is a profiled blade like member situated beside the deadlocking slide within the casing. This member has a raised portion 36 which, when the cylinder cam 7 has moved into its second range of movement, engages with the cam to bias the cylinder cam away from a position within its first range of movement thereby restraining the cylinder cam in its second range of movement. Preferably the rocker has a raised portion 37 within a straight portion 38 said raised portion being engageable by a shoulder 39 on the deadlocking slide whereby when the deadlocking slide has been moved to the deadlocking position these shoulders 39 and 37 engage to restrain the deadlocking slide in the deadlocking position. The rocker is N 8 biased by spring 40 towards engagement with both the cylinder cam and the shoulder 39 on the deadlocking slide.

The invention also provides a multipoint lock including a drive mechanism by which remote locks are actuated. The drive mechanism 41 comprises a pair of slides 42 and 43 supported within a casing 44 for counter translatory movement wherein each slide has an inwardly projecting pin 45, 46 which engages in one of a pair of opposite slots 47, 48 respectively in a disc like member supported between the slides for angular displacement about a point between the slots- Movement of one slide in one direction causes the disc member to rotate and drive the other slide in the opposite direction. The deadlocking member 4 is adapted to engage one of the slides of this drive mechanism by being of extended length and having two pins which engage in two recesses within one of the slides of the drive mechanism. Actuation of the deadlocking slide causes one of the slides of the drive mechanism to move in one direction and the other slide to move in the other direction. Remote locks are positioned above and below the drive mechanism These locks are coupled by bars 49 and 50 so that actuation of the deadlocking slide to the deadlocking position o* causes the bars to drive the remote locks to their fully extended deadlocked position.

pThe remote locks 51 comprise a casing 52 in which a displaceable bolt 53 is supported. This bolt is operated by a pivotally supported lever 54 having on one side of the pivot point an arm with a pin 55 which engages in a hole 56 in the end of a bar and on the opposite side having a pin which engages in a profiled slot in the side of the bolt 53 in slide follower relationship. The pivotally supported member operates within two ranges of movement. In the first range the pin slides within the slot 54 to drive the bolt to and from the extended and retracted positions while in the second range of movement 55 when the bolt is fully extended the slot is angled so that its walls are 9 substantially orthogonal to the pivot point of the pivotal member so that the pin can slide within this portion of the channel without causing the bolt to move to deadlock the bolt in the extended position. Movement of the slide to the deadlocking position simultaneously causes the latch bolt to be deadlocked and the remote locks to be deadlocked.

Throughout this specification and claims which follow, unless the context requires otherwise, the word comprise" and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers and the positional prepositions such as up, down, rear which are used to assist in description of the preferred embodiments have in general no absolute significance.