AU761237B2 - Locks - Google Patents

Description

Invention Title: Locks t:oeee S"Field of the Invention oooo This invention relates to door locks and in particular relates to locks for security doors.

Summary of the Invention According to the invention there is a lock for a door including a casing, a first displaceable member, a single bolt bywhich to restrain door from being moved in a opening direction comprising an outwardly biassed latch bolt having a leading end S characterized by similarly curved or bevelled or otherwise contoured sides, said latch 15I bolt being rectilinearly displaceable between a fully extended position where the leading end protrudes from the casing and a retracted position where the leading end is within the casing, and an auxiliary bolt having a leading portion displaceable from an extended position where the leading portion protrudes from the casing, S. 20 the lock being characterized by a pre-latching configuration in which the latch bolt is restrained from displacing towards the fully extended position by the first displaceable member itself restained against displacement by the auxiliary bolt.

.In a form of the invention, in the pre-latching configuration the first displaceable member is urged by the latch bolt to displace but is restrained from doing so by the auxiliary bolt.

In a form of the invention, the pre-latching configuration is characterised by the auxiliary bolt being in the extended position from which it is displaceable to cause the first displaceable member to become unable to restrain the latch bolt In a form of the invention, in the pre-latching configuration the latch bolt is restrained in a partly extended position restrained from displacing towards the fully extended position but free to be displaced towards the retracted position.

oo 5 In a form of the invention, the first displaceable member comprises an angularly displaceable member supported by the casing.

In a form of the invention, an engaging shoulder of the first displaceable member is engaged with an engageable shoulder of the auxiliary bolt when the lock is in the pre- 1o latching configuration. Preferably,the engageable shoulder is displaceable by auxiliary bolt displacement to be removed from the locus of movement of the engaging shoulder.

In a form of the invention, the invention includes operating means by which to S cause the latch bolt to be displaced towards the retracted position said operating means including a hand operable member operably connected to the latch bolt by a drive arm.

Prefewrably, the first displaceable member includes the drive arm.

According to the invention there is a door including a casing, an auxiliary bolt having a leading portion displaceable from an extended position where the leading 20o portion protrudes from the casing, a single bolt by which to restrain door from being moved in a opening direction comprising an outwardly biassed latch bolt having a leading end characterized by similarly curved or bevelled or otherwise contoured sides, said latch bolt being rectilinearly displaceable between a fully extended position where "•'the leading end protrudes from the casing and a retracted position where the leading end is substantially within the casing, operating means by which to cause the latch bolt to be displaced towards the retracted position including a hand operable member operably connected to the latch bolt by a drive arm, the lock being characterized by a pre-latching configuration in which the latch Ol. 30 bolt is restrained from displacing towards the fully extended position by the operating means itself restained against displacement by the auxiliary bolt.

I

Preferably, the hand operable member is operably connected to the latch bolt by a drive arm and the pre-latching configuration is characterised by the latch being restrained by the drive arm itself restained against displacement by the auxiliary bolt.

lO** 5 In a form of the invention, the invention includes a strike plate having an aperture through which the latch bolt has passage, said latch bolt being displaced from the partly extended pre-latching position away from the strike plate during latching to be subsequently displaced by the biasing means through the aperture.

In a form of the invention, the invention includes a deadlocking slide having a leading end, a key operable cylinder and a hand operable locking lever, said deadlocking slide being displaceable by operation of the cylinder and by operation of the locking lever to displace to and from a deadlocking configuration in which the S. deadlocking slide cooperates with the latch bolt to restrain the latch bolt from being 15 displaced from the fully extended position.

In a form of the invention, the auxiliary bolt leading portion characterized by similarly curved or bevelled or otherwise contoured sides.

00 900 0: o0 O oo*** Description of the Drawings 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 schematic plan view of a lock body and strike plate, Figure 2 is a schematic side view of an embodiment of the lock body with the latch bolt restrained in a partly extended position, Figure 3 is a schematic side view of another embodiment of the lock body with the latch bolt restrained in a partly extended position, Figure 4 is a schematic side view of the lock of Fig 3, where the latch bolt is in 0io the fully extended position.

IIi.:i Description of the Preferred Embodiments The lock, as shown in Figures 1 to 4, comprises a box like casing 10 having a S front wall 16, a rear wall 17, upper and lower walls 18 and side walls 18A herein also S 15 referred to as sides, a substantially rectangular latch bolt 20 supported in the casing and displaceable through an aperature 11 in the front wall of the casing and having a leading portioi displaceab. between a fully extended position where it protrudes from the casing and a retracted position where it is substantially within the casing. During normal S unlatching operation, the latch bolt 20 is displaced inwardly, towards the retracted o positon, against biasing means comprising spring 30 by a drive arm 40 which is supported within the casing for angular displacement about a pivotal axis and which S preferably has a fixed end portion supported at the pivotal axis on a cylindrical portion of cam 50 which is supported in circular apertures in the side walls 18A of the casing and a free end radially displaced fom the axis. The cam 50 is connected to an operating lever 61 in an external lever assembly as described below.

As is well known, normial unlatching comprises rearward displacement of the latch bolt to disengage the aperture of the strike plate, opening of the door whereapon the auxiliary bolt moves to the extended position as it becomes unrestrained by the strike plate, and controlled release of the lever whereapon the latch bolt moves outwardly from the retracted position to the latching position in which it is restrained in readiness for subsequent latching.

The cam 50, in normal unlatching operation, engages the drive arm 40 to cause it to rotate to cause the drive arm 40 to engage a sidways protruding shoulder21 of the latch bolt 20 to drive the latch bolt 20 rearwardly.

The cam 50 is coupled to a lever 61 in an external lever assembly 60 by a rectangular shaft. Lever rotation to unlatch the lock causes the cam 50 to rotate to cause the free end of the drive arm to displace rearwardly to displace the latch latch bolt towards the retracted position. There is preferably some free movement in the operable io coupling between the cam 50 and drive arm 40 so that the cam 50 and lever 61 can remain undisplaced while the latch bolt 20 displaces between the fully extended and retracted positon.

The cam 50 preferably comprises a cylindrical portion integrally attached to a S 15 disclike portion 52 which supports a sideways protruding pin 53 displaced from the axis of rotation of the cam 50. It is configured such that when the latch bolt 20 is fully extended this pin 53 is adjacent a substantially radial protruding s;',ulder 42 of the drive ,uld tesoudr42cokws o as ted'r r 4 of th drie S arm 40. Cam rotation caused by hand operable lever 61 rotation causes the pin 53 to urge and displace the shoulder 42 clockwise to cause the drive arm 40 to angularly 20 displace to cause the latch bolt to move towards the retracted position.

Supported within the casing there is also an auxiliary bolt 70 which is displaceable through an aperture 12 in the front wall 16 of the casing and having a leading portion displaceable between an extended position where it protrudes from the casing as shown in Figure 2 to 4, and a retracted position where it is substantially within the casing as shown in Figure 1. The auxiliary bolt is outwardly biassed by spring 31. In practice the auxiliary bolt 70 is inwardly displaced by sliding up a ramped surface 2 of the strike plate 1, as shown in Figure 1.

The lock includes a deadlocking slide 80 displaceable by operation of a key operable cylinder 81 and displaceable by operation of an external hand operable locking lever 82 within a lever assembly 60. The deadlocking slide can be displaced between a first position, for convenience referred to as an unlocked position, and a second position for convenience referred to as a deadlocked position in which the deadlocking slide's leading edge 83 locates behind a raised shoulder 22 of the latch bolt 20 to restrict inward displacement of the latch bolt from the fully extended position. When the latch bolt 20 is restrained in the fully extended position the free end of the drive arm 40 is restrained from inwardly displacing through its engagement with the shoulder 21.

The cylinder includes a cam 81A which has an armed extension 81B which locates between an upper shoulder 84 and a lower shoulder 86 bounding and defining a recess within the side of the deadlocking slide and adjacent the cylinder as shown in Figures 2 to 4. Rotation of the cam in a clockwise direction causes the arm 81B to engage the shoulder 84 to urge the deadlocking slide towards the latch bolt while rotation in the ant-clockwise direction causes the arm 81 B to engage the shoulder 86 to urge the deadlocking slide away from the latch bolt. This is well known and common to most security door deadlocks.

The locking lever 82 is connected to an armed cylindrical cam 85 by a rectangular rod 85A. The cam 85 is supported in circular aperatures in the side walls ,A the casing while its armed extension 85B supports a pinned side protrusion 87 which 20 locates in a substantially horizontal slotted recess 88 in the side of the deadlocking slide 20 whereby the deadlocking slide can be moved towards the latch bolt by angular displacement of the locking lever in a clockwise direction and away from the latch bolt by anti-clockwise movement and as is well known in security door locks.

In a preferred embodiment as shown in Figure 1 and shown in Figure 2, the latch bolt 20 is located adjacent a fin-like protrusion 19A projecting inwardly from a side of the casing to extend from the front wall of the casing (herein also referred to as a fin portion) to terminate in a shoulder 19. The latch bolt 20 has a diplaceable portion preferably comprising an angularly displaceable rocker 22 which is supported on a pin 23 rearwardly on the latch bolt 20. This rocker has at a free end, radially displaced from the axis of rotation defined by the pin 23 and forward of the pin 23, a shoulder 25 which is engageable with the shoulder 19 of the fin portion and it is biassed by spring 26 towards the fin. When the auxiliary bolt 19 is extended and the latch bolt 20 is disposed so that the shoulder 25 is rearwardly disposed of the shoulder 19, the rocker is displaceable by the spring 26 so the shoulder 25 engages with the shoulder 19 of the fin portion to thereby restrain the latch bolt 20 from displacing towards the fully extended position; in normal usage of this preferred embodiment, the latch bolt during unlatching is retacted by operation of lever 61 to or adjacent the fully retracted position, subsequent opening of the door supporting the lock enables the auxiliary bolt to displace to the extended position during which motion the rocker 22 is displaced to a position in which the shoulder 25 is disposed directly behind shoulder 19 so that on subsequent displacement of the latch bolt under the action of the resilient biasing means the shoulder 19 is carried forward till it engages the shoulder 19 this configuration in a preferred embodiment, corresponding to a partly extended latch boit 20 as shown in Fig.

S 2. The subsidiary latch bolt member is prevented from angnlarly displacing clockwise further under the action of spring 26 by a downwardly projecting leg 22A which engages 5 a shoulder of the latch bolt to maintain the rocker 22 within a normal operating range.

The points of contact of the shoulders 19 and 25 when engaged comprise substantially vertically disposed .edges as shc, in Fig. 2. Adjacent the shoulder 25 and on a side disposed towards the casing fin is a ramped portion 24 which protrudes above S: the casing fin portion to be engageable with the auxiliary bolt which is supported adjacent the upper edge of the fin portion for horizontal rectilinear displacement as shown in Fig. 2 The auxiliary bolt, as shown in Fig 2, has a ramped portion 73 adjacent the fin shoulder 19 which is engageable with the ramp 24 to displace the ramp 24 away from the auxiliary bolt and to consequently move the shoulder 25 out of longitudinal alignment with the shoulder 19 to preclude engagement to enable the latch bolt 20 to be fully outwardly displaced by the spring During normal operation of this embodiment both the auxiliary bolt and latch bolt are correspondingly depressed through engagement with the strike plate as shown in Fig 1 the auxiliary bolt is then retained depressed by the strike plate while the latch bolt moves outwardly from a substantially fully retracted position to the fully extended position to engage in an aperture in the strike plate. During this outward movement the ramped face 24 slides down the ramped face 73 of thethen stationary displaced, substantially retracted, auxiliary bolt to displace the shoulder 25 out of longitudinal alignment with the shoulder 19 and then during further displacement of the latch bolt the rocker free end slides along a substantially horizontal edge of the auxiliary bolt till the ramped portion 24 reaches the shoulder 19 whereapon the ramped portion 24 slides down the shoulder 19 to further displace the rocker free end to allow the latch bolt to displace to the fully extended position.

In another preferred embodiment shown in Figure 1, Figure 3 and Figure 4, the auxiliary bolt has one or more engageable shoulders 71 adjacent a shoulder 41 of the drive arm 40 with which it is engageable to restrain the free end of the drive arm from displacing forwardly to restrain the latch bolt from displacing outwardly under the action of the spring 30. Preferably, as shown in Figure 2, the auxiliary bolt has only one such S 15 shoulder 71.

"'Wi When the auxiliary bolt is inwardly displaced during normal iatchirng engagement with the strike plate, a rear preferably angled face 72 of the auxiliary bolt slides up a S ramped abuttment 13 of the wall of the casing so that the shoulder 71, in addition to being inwardly displaced, displaces away from the drive arm 40 to displace from the locus of movement of the shoulder 41 to exclude engagement with the drive arm.

During normal aperation of this embodiment, both the auxiliary bolt and latch bolt are correspondingly inwardly displaced through engagement with the strike plate as shown in Fig 1; the auxiliary bolt is retained depressed by the strike plate while the latch bolt moves outwardly to engage in an aperture in the strike plate. During the inward movement the auxiliary bolt portion 72 is displaced away from the bolt and the shoulder 71 is correspondingly moved out of the locus of movement of the shoulder 41 of the drive arm thereby excluding enngagement and allowing the bolt to displace to the fully extended position under the action of the spring 31.

In preferred embodiments, where the lock accommodates both left and right handed doors the auxiliary bolt 70 has a leading portion comprising edges which are 8 similarly curved or bevelled or otherwise contoured as shown in Figure 1 wherein to assist inward displacement of the auxiliary bolt through engagement with the strike plate 1 on either side of the auxiliary bolt.

As is common, the strike plate has an aperature in which the latch bolt 20 may engage and a landing beside the aperature with which the auxiliarly bolt engages and by which it is held depressed. The strike plate also has a leading angled, ramped portion 2 to assist inward displacement of both bolts during latching wherein the bolts slide relatively up the ramped portion 2 to be diplaced inwardly as is well known.

:In preferred embodiments where the lock has a pre-latching configuration where the latch bolt is retained partly extended prior to latching and the lock accommodates Sboth left and right handed doors, both sides of the latch bolt are similarly curved or bevelled or otherwise contoured, as shown in Figure 1, so that engagement of either S 15 side of the latch bolt with the strike plate will cause the latch bolt to be displaced towards the retracted position.

In the preferred embodiments shown in Figures 1, 3 and 4, the shoulders 71 and 41 are configured such that the these shoulders engage to restrain the latch bolt from 20 further extending, when the latch bolt is in the partly extended position. In the embodiments shown in Figures 1 and 2 the shoulders 19 and 25 are configured such that the these shoulders engage to restrain the latch bolt from further extending, when 'i the latch bolt is in the partly extended position Throughout this specification and claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Throughout this specification and claims which follow, unless the context requires otherwise, the positional prepositions such as rear, forward are used to assist in description of the preferred embodiments and have in general no absolute significance.