AU2013100176B4 - Push lock - Google Patents

Abstract

A lock including structure fixable to a first member having a first side and second side; at least one engagement feature; a button inwardly pushable along an axis to move the engagement feature from an unlatched position, in which a second member is 5 moveable relative to the first member, to a latching position in which the engagement feature is positioned to engage the second member to limit movement of the second member relative to the first member; wherein the fixable structure includes a first structural portion positionable on the first side; and a second structural portion positionable on the second side; and the first structural portion and the second 10 structural portion are mutually engageable to sandwich a portion of the first member between the first structural portion and the second structural portion to mount the lock.

Description

PUSH LOCK Field of the invention The present invention relates to locks including pushable button portions, hereinafter "push locks". 5 Background of the invention Push locks are commonly used to lock cupboards with sliding front panels, cabinets such as display cabinets with sliding glass front panels, sliding windows, and sliding doors. Whilst not being an admission of common general knowledge, one type of push lock, which may be fastened to the front surface of the sliding window, has a locking 10 arm which is adapted to project through and behind the rear surface of the sliding window when the lock is pushed into a locking position. By projecting behind the rear surface of the sliding window when the push lock is locked, the locking arm may abut against a surface or catch located behind the window to prevent it from being slid open. Unlocking of the push lock causes the locking arm to 15 be retracted out of alignment with the catch or abutting surface thereby allowing the sliding window to be freely slid open. A disadvantage associated with this type of push lock is that a key must be inserted into the push lock in order to lock or unlock it. This may be particularly undesirable when for example, the lock is used for home windows and the occupant does not wish to have to 20 use a key every time they lock or unlock the window. Another disadvantage associated with this type of push lock is that water may seep into the lock from the environment at the rear of the sliding window. Yet another disadvantage associated with this type of lock is that it can be difficult to install in confined spaces.

2 It is not admitted that any of the information in this specification is common general knowledge, or that the person skilled in the art could be reasonably expected to have ascertained or understood it, regarded it as relevant or combined it in anyway at the priority date. 5 SUMMARY OF THE INVENTION One aspect of the invention provides a lock including structure fixable to a first member having a first side and second side; at least one engagement feature; a button inwardly pushable along an axis to move the engagement feature from an unlatched 10 position, in which a second member is moveable relative to the first member, to a latching position in which the engagement feature is positioned to engage the second member to limit movement of the second member relative to the first member; wherein the fixable structure includes a first structural portion positionable on the first side; and 15 a second structural portion positionable on the second side; wherein the first structural portion and the second structural portion are mutually engageable to sandwich a portion of the first member between the first structural portion and the second structural portion to mount the lock. The mutual engagement is preferably a threaded engagement. Advantageously an anti 20 rotation mechanism may be arranged to prevent reversal of the threaded engagement. The anti-rotation mechanism may include at least one tooth carried by one of the first structural portion and the second structural portion and arranged to engage a recess carried by the other of the first structural portion and the second structural portion; e.g. the anti-rotation mechanism may include a ratchet and a pawl. The anti-rotation mechanism is preferably 25 inaccessible when the lock is installed to prevent removal of the lock.

3 The engagement feature is preferably an axially extending arm portion of the button. The button is preferably biased outwardly. Also disclosed is a lock mountable to a first member for limiting movement of a second member relative to the first member, 5 the first member having a first side, a second side and an aperture therebetween and separating a first environment on its first side from a second environment on its second side, the lock including 10 structure fixable to the first member; at least one engagement feature; a button accessible from the first environment to be pushed inwardly along an axis to move the engagement feature from an unlatched position, in which the second member is moveable relative to the first member, to a latching postion in which the 15 engagement feature is exposed to the second environment and positioned to engage the second member to limit movement of the second member relative to the first member; and a sealing arrangement to substantially prevent water travelling from the second environment to the first environment via the aperture when the engagement feature is in its latching position. 20 Preferably the sealing arrangement includes a first sealing portion for sealingly engaging about a periphery of the aperture; and a second sealing portion for sealingly engaging the button. The first sealing portion may include a first resilient sealing member, e.g. a rubber washer, 25 which is preferably positioned to be compressed between a portion of the fixable structure and the first side.

4 The second sealing portion may include a second resilient sealing member positioned to be compressed between a portion of the fixable structure and the button when in its latching position. Also disclosed is a lock mountable to a first member for limiting movement of a second 5 member relative to the first member, the first member having a first side and second side, the lock including structure fixable to the first member at least one engagement feature; a button inwardly pushable along an axis to move the engagement feature from an unlatched 10 position, in which the second member is moveable relative to the first member, to a latching position in which the engagement feature is positioned to engage the second member to limit movement of the second member relative to the first member; and a mechanism to retain the button in its inward position; the mechanism including a key receiving portion and being 15 lockable such that the mechanism is releasable by hand to permit movement of the engagement feature to the unlatched position without a key; and deadlockable such that a key complementary to the key receiving portion is required to release the mechanism to move the engagement feature to the unlatched position. The mechanism may include an engagement member carried by one of the button and the 20 fixable structure; wherein the other of the button and the fixable structure includes structure complementary to the engagement member; and the engagement member is biased to move transversely to the axis to engage the 25 complementary structure when the button is pushed inwardly to retain the button in its inward position.

5 Preferably at least one of the engagement member and the complementary structure include at least one can portion to, when the mechanism is locked, drive the engagement member to move from said engagement with the complementary structure to release the mechanism in response to rotation of the button member in a first direction about the axis from a first angular 5 orientation to a second angular orientation. The at least one cam portions may include a chamfered edge on the engagement member co-operable with the complementary structure. Preferably the button includes the key receiving portion; wherein the key receiving portion is, with the complementary key 10 when the mechanism is locked, rotatable in a second direction about the axis to move blocking structure to block said movement of the engagement member from said engagement with the complementary structure to deadlock the mechanism; and when the mechanism is deadlocked, rotatable in the first direction about the axis to remove the blocking structure to undeadlock the mechanism. 15 In preferred forms of the invention the button and the fixable structure include or carry portions shaped to drive the button member to the first angular orientation as the button moves outwardly. By way of example, the shaped portions may include a projection projecting transversely from the button; and a groove defined by the fixable structure and in which the projection is received. 20 The engagement member is preferably carried by the button. Also disclosed is a push lock comprising: - a housing, - mounting means for mounting the housing to a fixture, 6 - a cylinder unit movable within the housing between a. retracted position for locking the push lock and a protracted position for unlocking the push lock, - a locking arm projecting from the cylinder unit, the locking arm being adapted to project through and beyond the housing and.the fixture when the cylinder unit is in the 5 retracted position, - securing means for securing the cylinder unit in the retracted position, wherein the securing means is adapted to be released by hand, without the use of a key, thereby enabling protraction of the cylinder unit and unlocking of the push lock. The securing means may be adapted to be deadlocked thereby preventing the securing 10 means from being released without first un-deadlocking the push lock with the use of a key. The key may be adapted to be removed from the lock when the securing means is deadlocked. The push lock may comprise stop means for limiting protraction of the cylinder unit so that it is not ejected from the housing during protraction. 15 The securing means may be adapted to be released by rotating the cylinder unit within the housing when the cylinder unit is in the retracted position. The securing means may comprise: - an engagement hole in the housing, and - an engagement member comprised by the cylinder unit, the engagement 20 member being adapted to project into the engagement hole in the housing when aligned therewith, thereby securing the cylinder unit in the retracted position. The engagement member may be spring loaded.

7 The engagement member may be adapted to be released from the engagement hole in the housing, thereby releasing the securing means. The engagement member may comprise a chamfered side edge. The chamfered side edge may enable rotation of the cylinder unit within the housing by hand so that the 5 engage ment member is released from the engagement hole in the housing. The engagement member may comprise a chamfered bottom edge. The chamfered bottom edge may reduce friction of the engagement member with the inside wall of 10 the housing during protraction or retraction of the cylinder unit. The engagement member may be depressed by hand in order to release it from the 10 engagement hole in the housing. The push lock may comprise guide means for returning the cylinder unit to its original orientation within the housing when the cylinder unit is moved to the protracted position following rotation in the retracted position. The guide means may be adapted to limit the amount of rotation allowed by the cylinder 15 unit within the housing when the cylinder unit is in the retracted position. The guide means may substantially prevent rotation of the cylinder unit within the housing when the cylinder unit is in the protracted position. The guide means may comprise: - -a guide slot in the housing, and 20 - a guide member comprised by the cylinder unit and projecting into the guide slot, whereby movement of the guide member is limited or directed by the confines of the slot. The guide slot may be d-shaped.

8 The cylinder unit may comprise a lock barrel and a key cylinder within the lock barrel. The key -cylinder may comprise a key slot adapted to receive a key. With the key inserted in the key slot, rotation of the key may cause concomitant rotation of the key cylinder within the lock barrel. This may cause retraction and release of the engagement 5 member from the engagement hole in the housing. The mounting means may comprise: - the housing, - a fixing member, - a male thread comprised by one of the housing or the fixing member, and 10 - a female thread comprised one of the housing or the fixing member, opposite to that of the male thread, wherein, by engaging the male and female threads, the fixing member and housing may be screwed together through a hole in the fixture so that the fixture is clamped therebetween. 15 The fixing member may comprise a plate. The plate may define one or more fastening holes adapted to receive a fastener therethrough. The fixing.member may comprise an arm hole for passage of the locking arm. The mounting means may comprise locking means for preventing unscrewing of the fixing member and the housing. The locking means may prevent unscrewing of the 20 fixing member and the housing when the fixture is clamped therebetween. The locking means may comprise a locking pin adapted to be inserted into aligned holes in the housing and the fixing member.

9 The mounting means may comprise sealing means for providing a substantially watertight seal between the housing and the fixing member when screwed together. The sealing means may comprise a sealing member. The sealing member may comprise an O-ring. The cylinder unit may comprise an annular recess for locating the 5 O-ring. The push lock may comprise a spring for urging the cylinder unit towards the protracted position. The spring may be located within the housing between the cylinder unit and a spring ledge proximate the base of the housing. The spring may be a tapered spring. The spring ledge may be comprised by the fixing member. The spring ledge may 10 surround the arm hole. The push lock may cormprise sealing means for providing a substantially watertight seal between the housing and the locking arm or cylinder unit. The sealing means may be adapted to substantially prevent water from entering the housing through the arm hole. The sealing means may comprise a sealing member which is adapted to be 15 compressed between the cylinder unit or locking arm and the housing. The sealing means may comprise an O-ring. Additionally, the sealing means may comprise an annular groove at the end of the locking arm which is attached to the cylinder unit. The annular groove may be adapted to locate the O-ring. The key cylinder may comprise a series of key leaves. The key leaves may be spaced 20 and arranged face to face. Each key leaf may have a key opening for passage of the key. The key leaves may be located in respective leaf slots. The leaf slots may be 20 arranged in a series. The leaf slots may each extend transversely through the key cylinder, with opposed entrances present at opposite ends of each leaf slot. When the key is inserted in the key slot, the key leaves may be completely withdrawn 25 into their respective leaf slots. When the key is removed from the key slot, the key leaves may project out from one end of their respective leaf slots.

10 The lock barrel may comprise a first pair of opposed leaf grooves which are adapted for alignment with the leaf slots. If the key is removed from the key slot when the first pair of opposed leaf grooves and leaf slots are aligned, the key leaves may project out from one end of their respective slots and into the aligned leaf groove, thereby substantially 5 preventing rotation of the key cylinder within the lock barrel. The lock barrel may comprise a second pair of opposed leaf grooves which are adapted for alignment with the leaf slots. If the key is removed from the key slot when the second pair of opposed leaf grooves and leaf slots are aligned, the key leaves may project out from one end of their respective slots and into the aligned leaf groove, thereby 10 substantially preventing rotation of the key cylinder within the lock barrel. The second pair of opposed leaf grooves may be arranged substantially perpendicularly to the first pair of opposed leaf grooves, When inserted in the key slot, turning of the key may be adapted to cause rotation of the key cylinder within the lock barrel. This may enable the leaf slots to be moved between 15 alignments with the first and second pairs of opposed leaf grooves. The lock barrel may comprise a grooved rim at one end for facilitating grip when rotating the cylinder unit by hand. The cylinder unit may comprise track means for guiding or limiting rotation of the key cylinder within the lock barrel. 20 The track means may prevent withdrawal of the key cylinder from the lock barrel. The track means may comprise: - a track slot in the lock barrel, and - a track member comprised by the key cylinder and projecting into the track slot, 11 whereby movement of the track member is limited or directed by the confines of the slot. The track member may be spring loaded. It may be urged into the track slot by the spring. The track member may comprise a track leaf. 5 The key cylinder may comprise an abutment member. The abutment member may protrude at the base of the key cylinder. The abutment member may be adapted to block retraction and release of the engagement member from the engagement hole in the housing, thereby deadlocking the push lock. When inserted in the key slot, turning of the key may be adapted to 10 cause concomitant movement of the abutment member into -a position whereby retraction and release of the engagement member is blocked. This may occur when the second pair of opposed leaf grooves are aligned with the leaf slots, Turning the key back to its original position may be adapted to cause concomitant movement of the abutment member into a position whereby retraction and release of the engagement 15 member is unblocked. This may occur when the first pair of opposed leaf grooves are aligned with the leaf slots. The abutment member may be adapted to urge the engagement member to retract and release from the engagement hole in the housing. When inserted in the key slot, turning of the key may cause concomitant movement of the abutment member so that it 20 urges the engagement member to retract and release from the engagement hole. -The engagement member may have front and rear sections against which the abutment member may abut. The push lock may comprise un external sleeve which connects to and covers the housing. The housing may comprise one or more ribs adapted to connect with the 25 external sleeve. The locking arm may comprise a threaded portion for fastening of an extension piece.

12 Also disclosed is a push lock comprising: - .a housing, - mounting means for mounting the housing to a fixture, the mounting means 30 comprising, 5 - a fixing member, - a male thread comprised by one of the housing or the fixing member, and - a female thread comprised by one of the housing or the fixing member, - . opposite to that of the male thread, wherein, by engaging the male and female threads, the fixing member and 10 housing may be screwed together. through a hole in the fixture so that the fixture is clamped therebetween, - a cylinder unit movable within the housing between a retracted position for locking the push lock and a protracted position for unlocking the push lock, - a locking arm projecting from the cylinder unit, the locking arm being adapted to 15 project through and beyond the housing and the fixture when the cylinder unit is in the retracted position, and - securing means for securing the cylinder unit in the retracted position. Also disclosed is a push lock comprising: - a housing, 20 - mounting means for mounting the housing to a fixture, 13 - a cylinder unit movable within the housing between a retracted position for locking the push lock and a protracted position for unlocking the push lock, - a locking arm projecting from the cylinder unit, the locking arm being adapted to project through and beyond the housing and the fixture when the cylinder unit is in the 5 retracted position, - securing means for securing the cylinder unit in the retracted position; and - sealing means for providing a substantially watertight seal between the housing and the locking arm or cylinder unit. The sealing member may comprise an O-ring. The locking arm may comprise an 10 annular groove for locating the O-ring. Also disclosed is a push lock comprising: - a housing, - mounting means for mounting the housing to a fixture, - a cylinder unit movable within the housing between a retracted position for 15 locking the push lock and a protracted position for unlocking the push lock, the cylinder unit comprising, - a lock barrel comprising first and second pairs of leaf grooves, and - a key cylinder within the lock barrel, the key cylinder comprising a series of key - leaves adapted to project into the first and second pairs of leaf grooves, and a key slot 20 adapted to receive a key which when inserted in the key slot and rotated causes concomitant rotation of the key cylinder within the lock barrel, thereby enabling the key leaves to be aligned with either the first pair of leaf grooves. or the second pair of leaf grooves, 14 - a locking arm projecting from the cylinder unit, the locking arm being adapted to project through and beyond the housing and the fixture when the cylinder unit is in the retracted position, and - securing means for securing the cylinder unit in the retracted position. 5 As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps. Brief description of the drawings I figures Preferred aspects of the invention will now be described with reference to -the 10 accompanying drawings, in which figures 1 to 38 illustrate a first embodiment of the invention and figures 39 and 40 illustrate a second embodiment of the invention. Figure 1 is an exploded isometric view of a push lock; Figure 2 is a top plan view of a fixing member of the push lock; Figure 3 is an isometric view of the fixing member; 15 Figure 4 is a front elevational view of the fixing member; Figure 5 is a side elevational view of the fixing member; Figure 6 is an isometric view of a housing of the push lock; Figure 7 is an isometric view of the housing rotated 1800 from Figure 6; Figure 8 is a top plan view of the housing; 20 Figure 9 is a top plan view of a section of the housing through line B-B as shown in Figure 12; 15 Figure 10 is a front elevational view of the housing; Figure 11 is a side elevational view of a section of the housing through line A-A as shown in Figure 8; Figure 12 is a rear elevational view of the housing; 5 Figure 13 is an isometric view of a lock barrel of the push lock; Figure 14 is a top plan view of the lock barrel; Figure 15 is an isometric view of the lock barrel rotated 180* from Figure 13; Figure 16 is a rear elevational view of the lock barrel; Figure 17 is a side elevational view of a section of the lock barrel through line A-A as 10 shown in Figure 14; Figure 18 is a front elevational view of the lock barrel; Figure 19 is an isometric view of an engagement member of the push lock; Figure 20 is a top plan view of the engagement member; Figure 21 is a rear elevational view of the engagement member; 15 Figure 22 is a side elevational view of the engagement member; Figure 23 is a front elevational view of the engagement member; Figure 24 is a bottom plan view of the engagement member; Figure 25 is an isometric view of a key cylinder of the push lock standing in an upright position; 16 Figure 26 is an isometric view of the key cylinder laid on its side; Figure 27 is an isometric view of the key cylinder in an upside down position; Figure 28 is an isometric view of the key cylinder rotated 180* from Figure 27; Figure 29 is an isometric view of the key cylinder laid on its side; 5 Figure 30 is transverse sectional view of the push lock showing the orientation of an abutment member when the push lock is locked; Figure 31 is a transverse sectional view of the push lock showing the orientation of the abutment member when the push lock is deadlocked; Figure 32 is an isometric view of the push lock when assembled and in a locked 10 position; Figure 33 is an isometric view of the assembled and locked push lock rotated 180* from figure 32; Figure 34 is a bottom isometric view of the assembled push lock when locked; Figure 35 is a transverse sectional view of the push lock when locked which illustrates 15. the arrangement of a rim of the key cylinder and a ledge of the lock barrel; Figure 36 is a transverse sectional view of the push lock when locked which illustrates the arrangement of key leaves of the key cylinder and leaf grooves of the lock barrel; Figure 37 is a transverse sectional view of the push lock when locked which illustrates the arrangement of a track leaf of the key cylinder and a track slot of the lock barrel 20 Figure 38 is a cut away view of the push lock when locked illustrating the arrangement between its inner components; 17 Figure 39 is an exploded isometric view of another push lock; and Figure 4d is a cut away view of the other push lock when locked illustrating the arrangement between its inner components. 5 Integer List 2 Push lock 54 Track slot 112 Notch 4 Mounting member 57 Leaf groove of first pair 6 Housing 58 Leaf groove of first pair 8 Lock barrel 61 Leaf groove of second pair 10 Engagement member 62 Leaf groove of second pair 12 Key cylinder 64 Annular groove 14 Extemal sleeve 66 Rim 16 Face plate 68 Ledge 18 Fastening hole 70 Floor section 20 Externally threaded portion 72 Front block section 22 Arm hole 74 Rear wall section 24 Tubular wall 76 Spring tab 26 Annular recess/step 78 Spring furrow 28 Guide slot 80 Chamfered side edge 30 Engagement hole 82 Key slot 32 Passage 84 Rim 34 Internally threaded recess 86 Key leaf 36 Spring ledge 90 Track leaf 38 Rib 94 Abutment member 40 Aperture 98 Engagement spring 42 Locking arm 100 Pin hole 44 Threaded recess 102 Tapered spring 46 Barrel hole 104 O-ring 48 Groove 106 Pin 50 Side channel 108 O-ring 52 Floor portion 110 Locking pin 18 Detailed description of the embodiments Referring to Figure 1, there is shown a push lock, generally designated 2. The push lock comprises a fixing member 4, a housing 6, a lock barrel 8, an engagement member 10, 5 a key cylinder 12, and an external sleeve 14. In use the lock 2 is fixed to a first member in the form of a window frame. The housing 6 and fixing member 4 are fixed relative to the frame and thus constitute fixable structure. The housing 6 is a tubular structure. The lock barrel 8 includes a cylindrical upwardly open cup like portion and a cylindrical 10 member extending downwardly from its base. The cylindrical member constitutes a locking arm.42. The housing 6, cup like portion of the lock barrel 8 and the locking arm 42 are aligned on a common axis. As will be described the locking arm 42 is movable to a position to engage and limit the movement of a second member in the form of a sliding panel carried in the frame. 15 The key cylinder 12 is internally carried within the cup like portion of lock barrel 8, which is in turn internally carried within the housing 6. The lock barrel is axially slidable within the housing 6 whereby the lock barrel 8 and the key cylinder 12 together constitute a button pushable along the common axis. The sleeve 14 is an optional cosmetic feature. 20 Figures 2 to 5 show the fixing member 4. The fixing member 4 comprises an elongate face plate 16 which defines a pair of fastening holes 18 towards opposite ends thereof, and an externally threaded portion which projects out from one side at the centre of the face plate 16. The externally threaded portion and face plate define an arm hole 22. Four spaced notches 112 are present at the top of the externally threaded portion. 25 Referring now to Figures 6 to 12, there is shown the housing 6. The housing comprises an upright cylindrical tubular wall 24. A lower end of the housing 6 is spanned by a floor. The floor is penetrated by a passage 32 in the form of an internally threaded bore 19 positioned concentrically to the wall 24 to define an upward facing annular ledge 36. A lower end portion 26 of the housing 6 is stepped down to a smaller external diameter thus defining a downwardly facing annular step. The tubular wall 24 defines a d-shaped guide slot 28, and a rectangular engagement -5 hole 30 opposite the guide slot 28. A pair of ribs 38 protrude outwardly from opposite sides of the tubular wall 24 near its base. A pair of coaxially aligned circular apertures 40 on opposite sides of the housing 6 pass through the tubular wall 24 and open into the passage 32. The apertures 40 are positioned immediately above the step down so as to leave a minimum wall thickness between the apertures and the downwardly facing 10 annular step. Figures 13 to 18 show the lock barrel 8. The cup like portion includes an upright cylindrical wall spanned by a floor. The locking arm 42 extends down directly from the centre of the floor. The locking arm 42 comprises a threaded recess 44 at its free end. An engagement hole 46 opens outwardly through the cylindrical side wall at the outer 15 end of an upwardly opening channel formation in the floor. The channel formation extends outwardly from the centre of the floor and defines the lower edge of the engagement hole 46. The channel formation has a horizontal floor and a pair opposed sides. A semi-circular groove 48 runs along the centre of the channel floor and separates two channel floor portions 52. The base of each channel side portion 20 includes a respective side channel 50 opening toward the centre of channel formation and defined by overhanging structure. The channel formation is-situated low down in the housing defining a minimum wall thickness between the groove 48 and a lower extent of the cup like portion. The lock barrel 8 further comprises a horizontal elongate track slot 54 which is 25 positioned above the hole 46 and extends part way around the cylindrical wall. An outwardly open blind bore 100 is concentrically aligned with the groove 48. Four inwardly opening axially extending grooves are equispaced about an interior of the cup like portion of the lock barrel 8 hereinafter referred to as leaf grooves. A first pair of 20 opposed leaf grooves, 57 and 58 respectively, extends vertically on opposite sides along the inner cylindrical wall of the lock barrel 8. Arranged perpendicularly to the first pair of opposed leaf grooves, 57 and 58 respectively, is a second pair of opposed leaf grooves, 61 and 62 respectively. 5 An outwardly opening annular groove 64 having a semi-circular cross section is present at the top of the locking arm 42 where it joins the base of the cup like portion of lock barrel 8. The top of the lock barrel comprises a stepped out circular rim 66 having external grooves for gripping. In this embodiment the circular rim defines a more or less circular 10 periphery of the button. Of course the button may not be round. Other shapes are possible. The lock barrel 8 includes a ledge 68 extending around its interior and adjacent its upward open end. The ledge 68 has a stepped profile including a first horizontal portion, a second -relatively higher horizontal portion. and circumferentially facing steps 15 therebetween. Referring now to Figures 19 to 24, there is shown the engagement member 10. The engagement member is shaped to complement and slide along the channel formation in the floor of the lock barrel 8. The engagement member is an integrally formed member including a floor section 70, a front D-shaped block section 72 stepping up from the front 20 of the floor section 70, a rear crescent shaped wall section 74 extending up from the rear of the floor section 70, a tab 76 protruding down from the front of the floor section 70, a furrow 78 extending rearwardly along the underside of the floor section away from the tab 76. The front block section 72 has a chamfered right side edge 80 as well as a chamfered 25 bottom edge 82. - Figures 25 to 29 show the key cylinder 12. The key cylinder 12 comprises a key slot 82, outwardly projecting rim 84, a series of spaced face to face key leaves 86 which extend transversely through the key cylinder within respective leaf slots 88, a track leaf 90 21 extending transversely through. the key cylinder within leaf slot 92, and an abutment member 94 protruding at the base of the key cylinder 12. An underside of the rim 84 has a. stepped profile cooperable with the ledge 68 of the lock barrel 8. The abutment member 94 has a rectangular shaped first portion with a curved edge and a rectangular 5 shaped second portion with a curved edge. Each of the key leaves 86 has a key opening (not shown) for passage of a key therethrough. The exploded parts of the push lock 2 as shown in Figure 1 may be assembled in the following manner (see also Figure 38): - An engagement spring 98 is located in the groove 48 of the lock barrel 8. 10 - The engagement member 10 is inserted into the engagement hole 46 of the lock barrel 8 with the spring tab 76 of the engagement member 10 abutting against the end of the engagement spring 98. - The engagement member is depressed further into the engagement hole 46 to compress the engagement spring 98 so that the front block section 72 of the 15 engagement member is flush with the cylindrical wall of the lock barrel 8. - The spring loaded track leaf 90 of the key cylinder 12 is retracted to clear the way for the key cylinder to be inserted -into the lock barrel 8. - Keeping the engagement member 10 depressed inside barrel hole 46, the key cylinder 12 is located within the lock barrel so that the rim 84 of the key cylinder 20 rests upon the ledge 68 of the lock barrel, the key slot 82 and key leaves are aligned with the first pair of opposed leaf grooves 57 and 58, and the track leaf 90 of the key cylinder is aligned with the track slot 54 of the lock barrel. - With the key cylinder correctly aligned inside the lock barrel, the track leaf 90 is protracted into the track slot 54 thereby preventing withdrawal of the key cylinder 25 from the lock barrel. In this position, the abutment member 94 at the bottom of the key cylinder adjacent (or bearing against) the floor 70 of the engagement member 10 between the front block section 72 and the rear wall section 74 in the 22 configuration shown in Figure 30. In this configuration, engagement member 10 is prevented from moving outwardly through the barrel hole 46, although being urged in that direction by the engagement spring 98, because it is blocked by abutment of the rear wall section 74 of the engagement member against the 5 abutment member 94. . A tapered compression spring 102 (see Figure 1) is placed inside the housing 6 so that the widest end of the spring lies on the ledge 36 in the housing. - An O-ring 104 is located in the annular. groove 64 at the junction between the locking arm 42 and the lock barrel 8. The 0-ring is compressed to provide a 10 water tight seal between the floor of the lock barrel 8 and an end face of the boss 20 of the fixing member 4 when the lock is assembled and the lock barrel 8 is in the retracted position, thereby substantially preventing water from moving through the passage 32. Therefore, in the case of a push lock installed on an external sliding window of a house with the lock face being accessible from inside 15 the house, water from outside the house which seeps in through the arm hole 22 of the mounting member 4 is blocked from entering inside the housing 6 by the O-ring 104 when the push lock is locked. . The lock barrel 8 is located within the housing 6, so that its locking arm 42 passes through the coils of the tapered spring in the passage 32 of the housing, 20 down through the internally threaded recess and out the bottom of the housing. The engagement member projects through the engagement hole of the housing thereby holding the locking barrel in the retracted position with the bore 100 of the lock barrel 8 aligned with the d-shaped guide slot. In this position, the grooved rim 66 sits proud of and adjacent the top of the housing. 25 - A pin 106 is inserted into the bore 100 of the lock barrel so that the pin 106 projects into the d-shaped guide slot 28. The push lock may be installed onto a fixture, such as a sliding door, in the following manner: 23 - Create a hole from face to face through the door, the hole being just large enough to receive the stepped down portion 26 of the housing 6. - Fit an O-ring 108 onto the stepped down portion 26 (see Figures 10 and 38). - Pass the locking arm 42 through the hole in the door until the O-ring 108 is 5 compressed firmly between the downwardly. facing step defined by the stepped down portion 26 and the surface of the door which surrounds the hole in the door. - Whilst maintaining the housing in this position, pass the fixing member 4 over the locking arm 42 so that the locking arm 42 projects through the arm hole 22 of the 10 fixing member 4. - Screw the externally threaded portion 20 of the fixing member 4 into the internally threaded recess 34 of the housing 6 so that the push lock 2 is fixed firmly to the door with the base plate 16 flat against the rear surface of the door. The circular apertures 40 are to be aligned with respective notches 112. 15 The O-ring 108, which remains compressed between the housing 6 and the surface of the door which surrounds the hole in the door, substantially prevents water from entering inside the housing between the sliding door and the entrance of the internally threaded recess 34. " To prevent unscrewing, locking pins 110 (see Figs I & 38) are passed through 20 circular apertures 40 and into aligned notches 112. - Optionally, screws can be passed through fastening holes 18 in the-face plate 16 as an additional means of fastening the push lock to the door. When locked, the locking arm should project through the hole in the door and beyond the door's rear surface, enabling the locking arm to catch against a fixed surface or 25 structure when someone tries to slide the door open. The locking arm 42 thus 24 constitutes an engagement feature. If a longer locking arm is 20 required, an extension piece can be screwed into the internally threaded recess 44 of the locking arm 42. Figure 30 and Figures 32 to 36 show the push lock 2 in a locked configuration which is capable of being unlocked by hand. In the locked configuration with no key inserted into 5 the key slot 82, the key leaves 86 project into leaf grooves 57 thereby holding the key cylinder fixed with respect to the lock barrel. The push lock is unlocked by hand by grasping the grooved rim 66 of the lock barrel and rotating it clockwise. As the lock barrel is rotated in a clockwise direction, the chamfered side edge 80. of the engagement member cooperates with a side of the engagement hole 30 of the housing 10 6. The chamfered side portion 80 functions as a cam portion, sliding along the side of the engagement hole 30 as the lock barrel 8 is rotated to drive the engagement member 10 to move inwardly from engagement with the engagement hole 30. As this occurs, the pin 106 moves clockwise until it abuts against a side wall of the d-shaped guide slot 28. With the engagement member 10 released, tapered spring 102 drives the lock barrel 8 15 out through the housing 6 to a protracted position. As the lock barrel moves towards the protracted position, it is caused to rotate in a counter clockwise direction back to its original orientation by the shape of the guide slot 28, the top of which also stops any further outward movement of the lock barrel 8 at the protracted position. With protraction of the lock barrel, the locking arm is withdrawn in through the hole in the 20 door into the housing. Thus, with the locking arm no longer projecting behind the rear surface of the door, it can no longer catch against another surface to prevent the door from sliding open. In order to lock the push lock, the lock barrel 8 is pushed all the way into the housing so that the engagement member 10 is aligned with, and projects out of, the engagement 25 hole .30 at the urging of the engagement spring 98 so as to engage the engagement hole. As the lock barrel 8 is retracted, the pin 106 moves down within the d-shaped slot 28 of the housing and the locking arm 42 extends out from the arm hole 22 in the fixing member and beyond the rear surface of the sliding door, causing locking of the push lock 2 when the lock barrel has reached the retracted position.

25 The push lock 2 may also be unlocked by a key. The key is inserted into the key slot 82 and through the key openings in the key leaves 86. This causes the key leaves 86 to withdraw from the first pair of opposed leaf grooves 57 and 58 into their respective leaf slots in the key cylinder 12 (see Figure 35). With the key leaves 86 withdrawn, the key 5 cylinder is now freed to rotate within the lock barrel 8. Thus as the key is turned in a clockwise direction, the key cylinder 12 is concomitantly rotated in the lock barrel 8. As the key cylinder 12 rotates in a clockwise direction, the track leaf 90 moves along in the track slot 54 of the lock barrel, the abutment member 94 at the bottom of the key cylinder 12 rotates from its position shown in Figure 30 in a clockwise direction, and the 10 rim 84 of the key cylinder moves in a clockwise direction on the ledge 68 of the lock barrel. Clockwise rotation of the abutment member 94 causes its second portion to push back against the rear wall section 74 of the engagement member 10, thereby causing retraction of the engagement member so that it is released from the engagement hole 30 in the housing 6. Clockwise turning of the key is limited by either abutment of the 15 track leaf 90 against an end of the track slot 54 of the housing, or abutment of part of the stepped rim 84 of the key cylinder against a part of the stepped ledge 68 of the lock barrel. With the key rotated clockwise and the engagement member 10 released, the tapered spring 102 urges the lock barrel into the protracted position, thereby unlocking the push 20 lock. With the key cylinder 12 rotated clockwise in the lock barrel 8 the key leaves 86 are no longer aligned with the first pair of opposed leaf grooves, nor are they aligned with the second pair of opposed leaf grooves. This means that the key cannot be removed from the key slot 82 as removal of the key causes protraction of the key leaves from their respective leaf slots in the key cylinder but such protraction is blocked by the 25 inner wall of the lock barrel. Thus to remove the key, the key must be counter rotated to an orientation in which the key leaves 86 are aligned with a pair of opposed leaf grooves. The push lock is locked by pushing in the button as previously discussed, with or Without the key in the key slot 82. 30 The push lock 2 may also be deadlocked so that it is unable to be unlocked by hand.

26 In order to deadlock the push lock 2, the key is inserted into the key slot 82, thereby withdrawing the key leaves 86 from the first pair of opposed leaf grooves, 57 and 58 respectively. Retraction of the key leaves enables the key cylinder 12 to be rotated in an anti-clockwise direction within the lock barrel by turning the key. The key is turned 90* 5 anti-clockwise so that the key leaves 86 are aligned with the second pair of opposed leaf grooves, 61 and 62 respectively, which is the deadlocked position. To fix the key cylinder in the deadlocked position the key is withdrawn from key slot 82 thereby causing projection of the key leaves 86 into the second pair of opposed leaf grooves, 61 and 62 respectively. 10 As the key cylinder 12 is rotated by the key to the deadlocked position, the track leaf 90 runs along in the track slot 54 of the lock barrel, the abutment member 94 at the bottom of the key cylinder rotates 900 in an anti clockwise direction from the orientation shown in Figure 30 to the orientation shown in Figure 31, and the stepped rim 84 of the key cylinder rotates on the stepped ledge 68 of the lock barrel. Any further anti-clockwise 15 movement of the key cylinder past the deadlocked position with the key inserted is prevented by either abutment of the track leaf 90 against an end of the track slot 54 or abutment of part of the stepped rim 84 against part of the stepped ledge 68. Referring to Figures 30 and 31, anti-clockwise rotation of the key cylinder results in the first portion of. the abutment member 94 being rotated into engagement with the front 20 block section 72 of the engagement member. Thus, any space between the front block section 72 and the abutment member 94 is alleviated, leaving no room for retraction of the engagement member 10 as the front block section 72 abuts against the first portion of the abutment member 94. Thus the abutment member 94 constitutes a blocking structure to block movement of the engagement member 10 from said engagement with 25 the engagement hole 30. The push lock is unable to be unlocked by hand until the key is used to rotate the key cylinder back to its original orientation whereby the key leaves 86 are aligned with the first pair of opposed leaf grooves, 57 and 58 respectively. The embodiment of figures 39 and 40 has a different mounting arrangement to the aforedescribed embodiment. The internally threaded passage 32 of housing 6 is 27 replaced by a downwardly extending externally threaded tubular boss 32' surrounded by a downwardly open annular channel. The annular channel carries a locking washer 110' which is formed of spring steel and includes a plurality of tabs deflected downwardly to form locking pawls. The washer has 5 a circular outer periphery. A notch formed in the periphery functions as a keyway: the notch engages a key in the form of a stub on an interior of the channel's external wall so that the washer is rotationally fixed relative to the housing 6. The fixing member 4 has an internally. threaded boss 20' which terminates in a plurality of asymmetric teeth spaced around it circumference. The teeth together constitute a 10 ratchet. To install this embodiment of the push lock, a hole is cut in the fixture to snugly accommodate the boss 20'. The boss 20' is inserted therethrough and then fitted with the O-ring 108. The washer 110' is fitted over the boss 32' and the boss 32' is then threadingly engaged with the boss 20'. As the housing is screwed in, the locking pawls 15 engage the ratchet to prevent unscrewing. The washer 110' and the boss 20' thus constitute an anti-rotation mechanism. Simultaneously the O-ring 108 is compressed between the fixture and the housing 6 to seal about the periphery of the aperture. The anti-rotation mechanism (i.e. washer 110' and the boss 20') are fully concealed so as to be unreleasable. As such the lock cannot be removed with destroying the lock or 20 the fixture. In this embodiment the O-ring 104 acts between the lock barrel 8 and the housing 6 when the button portion is pushed inwardly so the arm 42 is in its extended, latching, position. In another form of push lock (not shown) in accordance with the invention, there is 25 provided a solid lock barrel with a spring loaded engagement member, and no key cylinder is present. In this form, the push lock can be locked and unlocked by hand 20 only, with no provision for locking, unlocking, or deadlocking by key.

Claims (5)

1. A lock including structure fixable to a first member; at least one engagement feature; and 5 a button; the first member having a first side and a second side, and separating a first environment on its first side from a second environment on its second side, 10 the button being accessible from the first environment to be pushed inwardly along an axis to move the engagement feature from an unlatched position, in which a second member is moveable relative to the first member, to a latching position in which the engagement feature is positioned to engage the second member to limit movement of the second member relative to the first member; 15 the fixable structure including a first structural portion positionable on the first side; and a second structural portion positionable on the second side; the engagement feature projecting through the second structural portion; 29 the first structural portion and the second structural portion being mutually engageable to sandwich a portion of the first member between the first structural portion and the second structural portion to mount the lock.

2. The lock of claim 1 wherein the mutual engagement is a threaded 5 engagement.

3. The lock of claim 2 including an anti-rotation mechanism arranged to prevent reversal of the threaded engagement.

4. The lock of claim 3 wherein the anti-rotation mechanism is inaccessible when the lock is installed to prevent removal of the lock. 10

5. The lock of any one of claims 1 to 4 wherein the engagement feature is an axially extending arm portion of the button.