WO2021003533A1

WO2021003533A1 - A lock body for a sliding door

Info

Publication number: WO2021003533A1
Application number: PCT/AU2020/050716
Authority: WO
Inventors: Zhu WENHAO; Craig Anthony Caspersz
Original assignee: Allegion (Australia) Pty Ltd
Priority date: 2019-07-10
Filing date: 2020-07-10
Publication date: 2021-01-14
Also published as: CN113939638A; AU2020309101A1

Abstract

Disclosed herein is a lock body comprising: first and second escutcheons; a first lock cylinder extending into the lock body from the first escutcheon and towards the second escutcheon, the first lock cylinder having a user interface accessible from the external face of the first escutcheon to receive a user input to move the first lock cylinder to a first position to place the lock body in a unlocked state in which actuation of the lock body is permitted and to a second position to place the lock body in a locked state in which actuation of the lock body is prevented; a second lock cylinder extending into the lock body from the second escutcheon and towards the first escutcheon, the second lock cylinder having a user interface accessible from the external face of the second escutcheon to receive a user input to move the second lock cylinder to a first position to place the lock body in a unlocked state in which actuation of the lock body is permitted and to a second position to place the lock body in an locked state in which actuation of the lock body is prevented; wherein the first lock cylinder and the second lock cylinder are axially offset and substantially overlap within the lock body along parallel axes thereof.

Description

A LOCK BODY FOR A SLIDING DOOR

FIELD

[0001] The present invention relates to a lock body such as those that may be installed into a sliding door including, for example, a cavity sliding door.

BACKGROUND

[0010] Sliding doors are opened and closed in a direction parallel to the face of the door. Sliding door locks include a bolt with a hook which engages a strike plate to retain the door closed. Cavity sliding doors are similar, but are slidable into a cavity in a wall or door frame until the edge of the door in which the latch is mounted is substantially flush with the wall/door frame and the door is concealed within the cavity.

[0011] Sliding door locks generally include a face plate mounted flush with a side edge of the door and an actuation lever (or knob) which protrudes from one or both sides of the door.

However, such protruding levers (or knobs) cannot be used with cavity sliding doors as they prevent the door from completely sliding into the cavity. For this reason, cavity sliding door locks generally include a pair of recessed escutcheons mounted either side of the door, one of the escutcheons housing an actuation lever and the other usually housing an emergency release device. The lever(s) is/are manually pivoted to extend or retract the bolt from the face plate. A strike plate is mounted opposite the edge of the door and includes an opening complimentary to the bolt.

[0012] Sliding door locks generally include a lock bolt of rectangular cross section with a major (longer) axis parallel to the side edges of the door and a minor (shorter) axis normal to the bottom and top edges of the door. When the door is closed, the bolt can be extended which causes a hook to extend from the bolt to engage the strike plate and retain the door in the closed position. To open the door, the bolt is retracted which retracts the hook into the bolt and disengages it from the strike plate. For cavity sliding doors, a recessed pull tab can also be mounted on the door edge containing the face plate. The pull tab pivots out from the door edge so it can be gripped when the door is in the flush or fully open position (and thus the door itself cannot be gripped) and used to pull the door towards the closed position. [0013] The typical sliding doors’ thickness varies from 32mm up to 45mm. The doors normally have a <D54mm hole bored laterally through the panel and a 25mm hole bored longitudinally into the panel. The hole latching and locking mechanism needs to be accommodated within the two bore holes. Further, for cavity sliding doors, the locking and actuation mechanisms needs to fit within the lock body between the escutcheons without protruding outside the rims of the escutcheon (and thus preventing the door from being fully withdrawn into the cavity). For this reason, there are no key latches or only external key operated locks for cavity slider doors that fit into the standard door holes described above and thus, these sliding doors have generally been used in relatively low security settings, such as internally within a home.

[0014] Figure 1 provides an illustration of currently available door locks for sliding doors. As can be seen, this door locks include a single lock cylinder which juts outward from the door. Whilst such a single lock cylinder design has been used with sliding doors, such locks are not suitable for cavity sliding doors as the jutting lock cylinder prevents the sliding door from being fully withdrawn into the cavity.

[0015] Due to demand to optimize space in a home, there is a trend in the use of sliding doors and cavity sliding doors for garage entry into a home. As such, there is an increasing requirement for higher levels of security for sliding doors and cavity sliding doors without the need for complicated and expensive custom-made doors.

[0016] It is an object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages.

SUMMARY OF INVENTION

[0017] In one aspect of the invention, there is provided a lock body comprising: first and second escutcheons; a first lock cylinder extending into the lock body from the first escutcheon and towards the second escutcheon, the first lock cylinder having a user interface accessible from the external face of the first escutcheon to receive a user input to move the first lock cylinder to a first position to place the lock body in an unlocked state in which actuation of the lock body is permitted and to a second position to place the lock body in a locked state in which actuation of the lock body is prevented; a second lock cylinder extending into the lock body from the second escutcheon and towards the first escutcheon, the second lock cylinder having a user interface accessible from the external face of the second escutcheon to receive a user input to move the second lock cylinder to a first position to place the lock body in an unlocked state in which actuation of the lock body is permitted and to a second position to place the lock body in a locked state in which actuation of the lock body is prevented; wherein the first lock cylinder and the second lock cylinder are axially offset and substantially overlap within the lock body along parallel axes thereof.

[0018] In an embodiment, the first lock cylinder overlaps the second lock cylinders by at least 50% of the axial length of the second lock cylinder. Preferably, by at least 60% of the axial length. More preferably, by at least 70% of the axial length. Even more preferably, by at least 80% of the axial length. Most preferably, by at least 90% of the axial length.

[0019] In an embodiment, both the first lock cylinder and the second lock cylinder are displaced from, and arranged around, a central axis of the lock body.

[0020] In an embodiment, the user interface of the first lock cylinder is flush with an outer rim of the first escutcheon or recessed into the first escutcheon, and the user interface of the second lock cylinder is flush with an outer rim of the second escutcheon or recessed into the second escutcheon.

[0021] In an embodiment, the lock body further comprising a hook member having an extended position and retracted position; and wherein the first lock cylinder and the second lock cylinders are movable to the first position and the second position when the hook member is in the extended position.

[0022] In an embodiment, the first and second escutcheons each comprise a user actuator on an external facing surfaces of the first and second escutcheons; the lock body further comprises: a latch assembly comprising: a latch housing extending from between the first and second escutcheons and terminating at a face plate; a bolt retained within the latch housing, the bolt actuatable between an extended position in which a portion of the bolt extends from the latch housing and projects through an opening in the face plate and a retracted position in which the bolt is withdrawn within the latch housing; a drive assembly comprising a drive shaft coupled to each user actuator, wherein the drive assembly is engaged with the bolt, such that actuation of each user actuator rotates the drive shaft to move the bolt between the extended position and the retracted position; wherein rotation of the drive shaft is permitted when the lock body is in the unlocked state and prevented when the lock body is in the locked state.

[0023] In an embodiment each actuator is independently selected from the group consisting of: a push button, a hinged lever, and a rotatable lever. In one form of this embodiment, both actuators are rotatable levers.

[0024] In an embodiment, the drive shaft defines a central axis of the lock body.

[0025] In one form of the above embodiment, the first lock cylinder and the second lock cylinder are radially offset from the drive shaft.

[0026] In one form of the above embodiment, the first lock cylinder and second lock cylinder axes are parallel to an axis of rotation of the drive shaft.

[0027] 7 In one form of the above embodiment, the first lock cylinder and the second lock cylinder are on diametrically opposite sides of the drive shaft.

[0028] In one form of the above embodiment, the lock body further comprises an internal locking arrangement having a position of disengagement from the drive assembly when the lock body is in the unlocked state and a position of engagement with the drive assembly to prevent movement of the drive assembly when the lock body is in the locked state; wherein the first lock cylinder further comprises a lock element having a radial tab extending therefrom, the lock element rotatable to: (i) a first bias position, on actuation of the first lock cylinder to the first position, in which the radial tab biases the internal locking arrangement to the position of disengagement, and (ii) a second bias position, on actuation of the first lock cylinder to the second position, in which the radial tab biases the internal locking arrangement to the position of engagement; and wherein the second lock cylinder further comprises a lock element having a radial tab extending therefrom, the lock element rotatable to (i) a first bias position, on actuation of the second lock cylinder to the first position, in which the radial tab biases the internal locking arrangement to the position of disengagement, and (ii) a second bias position, on actuation of the second lock cylinder to the second position, in which the radial tab biases the internal locking arrangement to the position of engagement. [0029] In one form of the above embodiment, the drive shaft further comprises: a tab extending radially therefrom, wherein the tab comprises a drive pin; a cradle coupled to the bolt, wherein the cradle comprises a slot channel; and wherein the drive pin is held within the slot channel to provide a slotted link mechanism such that rotation of the drive shaft provides a linear movement of the cradle to move the latch between the extended position and the retracted position.

[0030] It is preferred that the locking body further comprises a radially extending channel portion having a channel length aligned with the linear movement of the cradle, the channel portion having a notch; the cradle further comprises a protrusion adapted to slide within the channel portion and align with the notch when the latch is in the extended position; and the protrusion is retained within the notch in when the internal locking arrangement is in the position of engagement, and the protrusion is slidable within the channel when the internal locking arrangement in the position of disengagement.

[0031] In one form of the above embodiment, the bolt comprises a hook member retained within the bolt, the hook member adapted to pivot outward from the bolt when the bolt is actuated to the extended position.

[0032] It is preferred that the latch housing comprises a sloped guide track and the hook member further comprises a shaft extending into the guide track to slide within the guide track to outwardly pivot the hook member from the bolt when the bolt is actuated to the extended position.

[0033] In an embodiment, the latch housing comprises first and second openings at opposite ends thereof with a linear axis therebetween, an internal passage between the first and second openings, and a linear cam in a wall of the internal passage between the first and second openings; the hook member comprises: a front hook portion (e.g. for engagement with a strike plate mounted to a doorjamb) having a leading edge projecting in a direction away from the linear axis; and a rear pivot portion comprising: a follower held in slidable contact with the linear cam; and a rotational mount operatively coupled to the drive assembly; wherein linear movement of the rotational mount along the linear axis causes the follower to slide over the linear cam and pivot the hook member about the rotational mount to move the hook member between: the extended position in which the front hook portion projects out through the first opening along the linear axis and is pivoted from the linear axis in the direction of the leading edge; and the retracted position in which the hook member is within the latch housing.

[0034] In one form of the above embodiment, the latch housing further comprises a hollow carriage slidable within the internal passage thereof, the hollow carriage comprising: a front bolt portion, and a rear portion, wherein: the hook member is rotationally mounted within the hollow carriage to the rear portion of the carriage via the rotational mount, the carriage is linearly moveable with linear movement of the rotational mount along the linear axis between the extended position in which the front bolt portion projects out through the first opening along the linear axis and the retracted position in which the carriage is within the latch housing; and the hook member is adapted to pivot outwardly to extend through an opening in the front bolt portion on movement to the extended position and to pivot inwardly to be housed within the carriage on movement to the retracted position.

[0035] In one form of the above embodiment, the linear cam is in the form of an elongate channel formed in or on the wall of the internal passage, the elongate channel generally having a channel length along the linear axis but sloped toward the first opening in the direction of the leading edge.

[0036] In one form of the above embodiment, the rotational mount is a cylindrical shaft with an axis orthogonal to the axis of the internal passage, and the rear portion of the carriage comprises corresponding radial recesses to receive the shaft.

[0037] In one form of the above embodiment, the latch assembly further comprises a link member, the link member comprising: a first end retained within the internal passage and connected to the hook member via the rotational mount, and a second end extending out of the second opening of the latch housing, wherein the link member is linearly driveable along the axis of the internal passage to move the hook member between the extended position and the retracted position.

[0038] In one or more embodiments, the lock body is actuatable to the locked state only when the bolt is in the extended position. [0039] In an embodiment, each user interface is a keyhole and the user input is in the form of a key. However, the skilled person will appreciate that other user interfaces and user inputs are possible, such as a finger prints, RFID tags, PIN, or other input passcode etc.

[0040] In an embodiment, the user interface of the first lock cylinder is a keyhole and the first lock cylinder is a first key barrel operatively connected to the keyhole of the first lock cylinder, and/or the user interface of the second lock cylinder is a keyhole and the second lock cylinder is a second key barrel operatively connected to the keyhole of the second lock cylinder.

[0041] In an embodiment, the lock body is adapted to fit within a hole of diameter between 52 and 56mm within a door.

[0042] In an embodiment, the lock body has a thickness within the range of from about 32mm and up to about 45mm as measured between internal surfaces of the first and second

escutcheons.

[0043] It is preferred that the face plate further comprises a pull tab having an opening for passage of the bolt therethrough, wherein the pull tab is pivotally mounted to the face plate at one end for pivoting between a first position substantially flush with the face plate and a second position angled with respect to the face plate to facilitate manual gripping of its other end.

[0044] Preferably, the hook is adapted for angular movement about its axis while being driven linearly to extend or retract through the face plate.

BRIEF DESCRIPTION OF DRAWINGS

[0045] Preferred embodiments of the abovementioned aspects of the invention will now be described, by way of examples only, with reference to the accompanying drawings.

[0046] Figure 1 provides two images of sliding door lock assemblies of the prior art.

[0047] Figures 2 and 3 show a double cylinder cavity slider lock set in the extended and retracted positions.

[0048] Figure 4 is an exploded view of the lock set of Figures 2 and 3. [0049] Figures 5 and 6 show working views of the lock set of Figure 4 in the unlocked extended and retracted positions.

[0050] Figure 7 is a working view of the lock set of Figure 4 in the locked extended position.

[0051] Figure 8 is a 3D view of the latch assembly coupled to one half of the lock body illustrating the lock cylinder engaged with the internal lock assembly with the latch locked in the extended position.

[0052] Figure 9 is a 3D view of the latch assembly coupled to one half of the lock body illustrating the lock cylinder engaged with the internal lock assembly with the latch unlocked in the extended position.

[0053] Figure 10 is an exploded view of a latch assembly in accordance with one embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

[0054] The present invention is directed towards a lock for a sliding door and/or a cavity sliding door that has two lock cylinders such that the sliding door or cavity sliding door can be locked and unlocked from both the external side of the door and the internal side of the door.

[0055] In a departure from standard lock design, the inventors have developed a new lock having two axially offset lock cylinders extending from the external and internal sides of the door. This is in contrast with standard lock design in which the lock cylinders are axially aligned. Having axially offset lock cylinders provides a more compact lock design in which the lock cylinders are held flush with the surface of the escutcheons or recessed therein. Thus, in preferred forms, this arrangement advantageously provides a lock assembly that can be locked and unlocked from both the external and internal sides of the door, is useful with cavity sliding doors since there is no lock cylinder jutting from the door preventing the sliding door from being fully held within the cavity, and provides an aesthetically pleasing design.

[0002] The invention will now be described with reference to the embodiments depicted in Figures 2 to 10 which illustrate a lock assembly 1 having a double cylinder lock set with a latch assembly according to the present invention. Figure 2 illustrates the lock assembly 1 actuated to the extended position in which the latch 16 and hook portion extend from the latch housing 10 for engagement with a striker plate. Figure 3 illustrates the lock assembly 1 actuated to the retracted position where the hook portion is withdrawn inside the carriage 15, and the carriage 15 and latch 16 are withdrawn inside the latch housing 10. Figure 4 is an exploded view of the lock assembly 1. Figure 5 and Figure 6 illustrate the interaction between the drive assembly and the latch assembly in the extended and retracted positions respectively. Figure 7 to 9 show the interaction between the lock cylinders and the internal lock arrangement. Figure 10 is an illustration of an embodiment of a latch assembly suitable for use with the lock body illustrated in Figures 2 to 9.

[0056] Referring to the drawings, there is shown various embodiments of a lock body 1 for a sliding door (not shown). It should be appreciated that when discussing sliding doors hereinafter it is envisaged that the lock body 1 can be used in sliding doors of varying thickness. Although, typical sliding doors have a thickness within the range of about 32 mm up to about 45 mm.

[0057] Sliding doors typically have a 54mm hole bored laterally through the door and a 25mm hole bored longitudinally in the door for installation of the lock body. The embodiments of the invention herein described are adapted to be fitted into the 54mm diameter hole and different thicknesses of doors. In a preferred form, the hole size could be anywhere between 52mm and 56mm.

[0058] The lock assembly 1 includes a face plate 5 mounted to a side edge of a door (not shown) by countersunk screws which pass through holes 7, 8. The lock assembly 1 includes a latch assembly 10 that extends from face plate 5 into the door. The latch assembly 10 is essentially a hollow rectangular box having a latch housing formed from two halves 10a, 10b having side walls 11 and open ends 12.

[0059] Broadly, the lock assembly 1 includes a face plate 5 mounted to a side edge of a door (not shown) by countersunk screws which pass through holes 7, 8. The lock assembly 1 includes a latch assembly (described below) 10 that extends from face plate 5 into the door and a lock body.

[0060] The lock body of the lock assembly 1 includes a drive assembly therein. The drive assembly comprises a drive plate 50 adapted to engage with a drive shaft 52 formed from the shaft portions of actuation levers 53. The levers 53 are accommodated within a recessed portion 65 of the external surfaces of escutcheons 60 which are to be mounted flush with the sides of the door. The escutcheons 60 include a centre hole 66 to receive the shaft portions 52 and levers 53. The escutcheons 60 also include a screw hole 67 adapted to allow the escutcheons 60 to be screwed to the door stop by way of countersunk screws 6. The actuation levers 53 cover the holes 67 after the levers 53 have been rotated to a locked position. The skilled person will appreciate that a variety of different levers may be implemented.

[0061] The cradle 75 having an elongate hole 80 to receive a shaft 81 on the drive member 50 to allow the drive plate 50 to move the cradle 75. The shafts 52 extend through hole 57 in drive member 50 and the slot in the cradle 75. This arrangement of the shaft 81 within elongate hole 80 provides a slotted link mechanism such that rotation of the drive shaft 52 is translated to a linear movement of the cradle 75. The cradle 75 has mounting arms 78 so that the cradle 75 can be operatively coupled to a latch (discussed below), and is thus is operable to move the latch between an extended position (e.g. engaged with the strike plate) and a retracted position. An overcentre spring 105 is provided to retain the cradle 15 under retention force in either an extended or retracted position.

[0062] The lock assembly 1 further comprises a pull tab 110 on the face plate 5 which pivotable between a position substantially flush with the edge of the door when the door is closed and a position angled outwardly from the door to facilitate manual gripping during closing of the door. The pull tab 110 includes pivot shafts 112 to be received within pivot guides 114 on the face plate 5. The pull tab 110 includes an opening 115 which mirrors in size the openings 17, 35 of the striker plate 30 and face plate 5.

[0063] The escutcheons 60 each include a further hole 70 to each receive a lock cylinder 71 therein. Thus, the lock body comprises a two lock cylinders 71, one of which is accessible from the escutcheon on the external side of the door and the other being accessible from the escutcheon on the internal side of the door. It should be noted that to fit both lock cylinders into a lock body which is sufficiently thin to be suitable for a sliding door (and in particular, a cavity sliding door) the lock cylinders are not axially aligned as is typical in a standard two-cylinder lock arrangement. Instead, each lock cylinder 71 is axially offset from each other, while substantially overlapping within the lock body along their parallel axis. This arrangement provides for a compact lock body design, since the thickness of the lock body is a function of the length of the lock cylinders 71 (e.g. in a standard design, the width of the lock body is dictated by a length that is twice the length of a single lock cylinder, since there are two lock cylinders that are axially aligned). In this regard, the lock cylinders are also atypically axially offset from the drive shaft. This in turn limits the internal space within the lock body for a latch assembly. Thus, making the latch assembly described herein useful in a sliding door lock assembly having a double cylinder lock set.

[0064] The two lock cylinders 71 interact with an internal lock arrangement to lock the latch assembly 10 in the extended position. Atypically, the lock cylinders 71 are axially offset from one another, and are also axially offset from the drive shaft 52.

[0065] The internal locking arrangement comprises a rotor 90 that is connectable by way of circlips 93 to the shaft 52. The rotor 90 further includes a tab with slot 94 having a notch 95 adapted to receive a protuberance 100 on the cradle 15. The protuberance 100 being aligned with and lockable within the notch 95 to lock the cradle 15 in extended positions.

[0066] The lock cylinder 71 includes a keyhole for receiving a key, rotation of a key within the keyhole causes rotation of lock element 92. Lock element 92 has a radial tab extending therefrom. The lock element 92 is rotatable between a first position in which the radial tab biases the internal locking arrangement to the position of engagement when the latch is extended, and a second position in which the radial tab biases the internal locking arrangement to the position of disengagement. In the position of engagement, the lock body is in a locked state in which movement/rotation of the drive assembly is not permitted. In the position of disengagement, the lock body is in an unlocked state and movement/rotation of the drive assembly is permitted. Figures 8 and 9 illustrate the internal locking arrangement in the position of engagement (i.e. locked) when the latch is extended and disengagement (i.e. unlocked) respectively.

[0067] As shown in Figure 8, to place the internal locking arrangement into the position of engagement (i.e. locked), the lock element 92 is rotated counter-clockwise such that the tab is biased against the rotor 90. This bias force causes a clockwise rotation of the rotor 90 which likewise causes rotation of the slot 94 such that protuberance 100 on the cradle 15 is located within the notch 95 of the slot 94. This locks the cradle 15 in position with the latch in the extended position. Whilst the cradle 15 is locked in position, movement/rotation of the drive assembly is not permitted. [0068] As shown in Figure 9, to place the internal locking arrangement into the position of disengagement (i.e. unlocked), the lock element 92 is rotated clockwise such that the tab is biased against the rotor 90. This bias force causes a counter-clockwise rotation of the rotor 90 which likewise causes rotation of the slot 94 such that protuberance 100 is moved out of notch 95 of the slot 94. This unlocks the cradle 15 which allows movement of cradle 15 and thus permits the latch to be moved between the extended and retracted positions such as in response to user actuation of levers 53.

[0069] A description of a preferred latch assembly and its operation is provided below.

[0070] The latch assembly 10 is essentially a hollow rectangular box having a latch housing formed from two halves 10a, 10b having side walls 11, open ends 12, and an internal passage defined therebetween.

[0071] A hollow bolt (or carriage) 15 is slidably mounted within the internal passage of the latch assembly 10 and has a bolt end 16. The hollow bolt 15 is adapted to extend from the face plate 5 in the extended position through opening 17 and retract substantially flush with the face plate 5 in a retracted position. A hook member 20 has a tip 21 on its distal end having a leading edge 27 (e.g. in the form of a hook). The other end is pivotally mounted within recess 23 of the hollow bolt 15 as discussed below.

[0072] Latch housing body halves 10a, 10b have holes 150 for receipt of fasteners (not shown) to secure the halves 10a, 10b together. The body halves 10a, 10b include elongate guide channels 152 and guide holes 153, both having camming surface 154, 155. These camming surfaces 154, 155 are important for pivoting the hook member 20 as is discussed below.

[0073] The hook member 20 at its pivot end includes three pairs of shafts 25, 28 and 29 extending away from the hook member 20 towards the body halves 10a, 10b. The first pair of shafts 25 extend through holes 156 in the hollow bolt 15 to locate within the guide holes 153 on the body halves 10a, 10b. This allows the hook member 20 to slide longitudinally with respect to the body halves 10a, 10b. The camming surfaces 155 push the tip 21 out of the recess 23 out of the carriage 15 and thus avoid the need for a spring to bias the hook in either of the extended or retracted positions. The second pair of shafts 28 extend through holes 160 in the hollow bolt 15 and to link member 74. The third pair of shafts 29 are locatable within the guide channels 152 on the body halves 10a, 10b, providing support as the hook member 20 slides longitudinally with respect to the body halves 10a, 10b. The camming surfaces 154 allow complimentary movement to the camming surfaces 155.

[0074] The latch assembly also comprises a link member or tail bar 74 having a hole 76 at one end for pivotal connection to the shaft 28 of the hook member 20 and at the other end, which projects out the opposite open end 12 from the hollow-bolt with cut-aways 77 for coupling to a drive shaft of a lock body as will be described below.

[0075] In use, a striker plate 30 is mounted to the door frame or opposite the edge of the door that contains the lock assembly 1 by countersunk screws which pass through holes 31, 32. The striker plate 30 includes an opening 35 of substantially complimentary size to the bolt end 16 of the latch assembly 15 and face plate opening 17. The opening 35 has an upper edge 36 for engagement with the tip 21 of hook member 20.

[0076] When the door is closed and the hollow bolt 15 is extended, the tip 21 extends from the hollow bolt 15 to a first position in engagement with the rear of the striker plate 30 adjacent the opening 35 and upper edge 36 to retain the lock 1 and thus the door in the closed position. The tip 21 retracts into the hollow bolt 15 in the initial stage of retraction of the carriage 15 for door opening to a second position. The tip 21 remains retracted in the hollow bolt 15 when the hollow bolt 15 is fully retracted into the latch housing 10.

[0077] Specific movements of the lock assembly 1 will now be described.

[0078] Figures 5 and 6 show moving parts of a double cylinder lock set in an extended/retracted position without being locked. In this situation, the latch (lock) can be driven by internal or external levers (levers) 53 to achieve connecting functionality the same as a connecting lock set.

[0079] Figure 7 shows moving parts of a double cylinder lock set in an extended position being locked. In this situation, neither the internal nor external lever 53 can drive the latch (lock) to a retracted position. That is, achieve a deadlock functionality. Only by using a key to rotate the cylinder cam (internal or external) can a user lock or unlock the latch. The interaction between the one of the lock cylinder and the internal lock assembly can be more clearly seen in Figures 8 and 9. [0080] The present invention in at least a preferred embodiment therefore provides a lockable cavity slider with double cylinder mechanism which allows users to lock or unlock the sliding door both outside and inside. The double cylinder lockable cavity slider can be fitted in existing door holes without requiring extra insulation space or modification.

[0081] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in other forms.

Claims

1. A lock body comprising: first and second escutcheons; a first lock cylinder extending into the lock body from the first escutcheon and towards the second escutcheon, the first lock cylinder having a user interface accessible from the external face of the first escutcheon to receive a user input to move the first lock cylinder to a first position to place the lock body in a unlocked state in which actuation of the lock body is permitted and to a second position to place the lock body in a locked state in which actuation of the lock body is prevented; a second lock cylinder extending into the lock body from the second escutcheon and towards the first escutcheon, the second lock cylinder having a user interface accessible from the external face of the second escutcheon to receive a user input to move the second lock cylinder to a first position to place the lock body in a unlocked state in which actuation of the lock body is permitted and to a second position to place the lock body in an locked state in which actuation of the lock body is prevented; wherein the first lock cylinder and the second lock cylinder are axially offset and substantially overlap within the lock body along parallel axes thereof.

2. The lock body of claim 1, wherein the first lock cylinder overlaps the second lock cylinders by at least 50% of the length of the second lock cylinder.

3. The lock body of claim 1 or 2, wherein the user interface of the first lock cylinder is flush with an outer rim of the first escutcheon or recessed into the first escutcheon, and the user interface of the second lock cylinder is flush with an outer rim of the second escutcheon or recessed into the second escutcheon.

4. The lock body of claim 1, wherein the first and second escutcheons each comprise a user actuator on an external facing surfaces of the first and second escutcheons; the lock body further comprises: a latch assembly comprising: a latch housing extending from between the first and second escutcheons and terminating at a face plate; a hook member retained within the latch housing, the hook member movable between an extended position in which a front hook portion of the hook member is pivotally extended through an opening in the face plate and a retracted position in which the hook member is withdrawn into the latch housing; a drive assembly comprising a drive shaft coupled to each user actuator, wherein the drive assembly is operatively engaged with the hook member, such that actuation of each user actuator rotates the drive shaft to move the hook member between the extended position and the retracted position; wherein rotation of the drive shaft is permitted when the lock body is in the unlocked state and prevented when the lock body is in the locked state.

5. The lock body of claim 4, wherein the first lock cylinder and the second lock cylinder are radially offset from the drive shaft.

6. The lock body of claim 4 or 5, wherein the first lock cylinder and second lock cylinder axes are parallel to an axis of rotation of the drive shaft.

7. The lock body of any one of claims 4 to 6, wherein the first lock cylinder and the second lock cylinder are on diametrically opposite sides of the drive shaft.

8. The lock body of any one of claims 4 to 7, wherein the lock body further comprises an internal locking arrangement having a position of disengagement from the drive member when the lock body is in the unlocked state and a position of engagement with the drive member to prevent movement of the drive assembly when the lock body is in the locked state; wherein the first lock cylinder further comprises a lock element having a radial tab extending therefrom, the lock element rotatable to:

(i) a first bias position, on actuation of the first lock cylinder to the first position, in which the radial tab biases the internal locking arrangement to the position of disengagement, and

(ii) a second bias position, on actuation of the first lock cylinder to the second position, in which the radial tab biases the internal locking arrangement to the position of engagement; and wherein the second lock cylinder further comprises a lock element having a radial tab extending therefrom, the lock element rotatable to:

(i) a first bias position, on actuation of the second lock cylinder to the first position, in which the radial tab biases the internal locking arrangement to the position of disengagement, and

(ii) a second bias position, on actuation of the first lock cylinder to the second position, in which the radial tab biases the internal locking arrangement to the position of engagement.

9. The lock body of any one of claims 4 to 8, wherein the drive shaft further comprises: a tab extending radially therefrom, wherein the tab comprises a drive pin; a cradle operatively coupled to the hook member, wherein the cradle comprises a slot channel; and wherein the drive pin is held within the slot channel to provide a slotted link mechanism such that rotation of the drive shaft provides a linear movement of the cradle to move the hook member between the extended position and the retracted position.

10. The lock body of claim 9, wherein: the locking body further comprises a radially extending channel portion having a channel length aligned with the linear movement of the cradle, the channel portion having a notch; the cradle further comprises a protrusion adapted to slide within the channel portion and align with the notch when the hook member is in the extended position; and the protrusion is retained within the notch in when the internal locking arrangement is in the position of engagement, and the protrusion is slidable within the channel when the internal locking arrangement in the position of disengagement.

11. The lock body of any one of claims 4 to 10, wherein: the latch housing comprises first and second openings at opposite ends thereof with a linear axis therebetween, an internal passage between the first and second openings, and a linear cam in a wall of the internal passage between the first and second openings; the hook member comprises: a front hook portion (e.g. for engagement with a strike plate mounted to a door jamb) having a leading edge projecting in a direction away from the linear axis; and a rear pivot portion comprising: a follower held in slidable contact with the linear cam; and a rotational mount operatively coupled to the drive assembly; wherein linear movement of the rotational mount along the linear axis causes the follower to slide over the linear cam and pivot the hook member about the rotational mount to move the hook member between: the extended position in which the front hook portion projects out through the first opening along the linear axis and is pivoted from the linear axis in the direction of the leading edge; and the retracted position in which the hook member is within the latch housing.

12. The lock body of claim 11, wherein the latch housing further comprises a hollow carriage slidable within the internal passage thereof, the hollow carriage comprising: a front bolt portion, and a rear portion, wherein: the hook member is rotationally mounted within the hollow carriage to the rear portion of the carriage via the rotational mount, the carriage is linearly moveable with linear movement of the rotational mount along the linear axis between the extended position in which the front bolt portion projects out through the first opening along the linear axis and the retracted position in which the carriage is within the latch housing; and the hook member is adapted to pivot outwardly to extend through an opening in the front bolt portion on movement to the extended position and to pivot inwardly to be housed within the carriage on movement to the retracted position.

13. The lock body of claims 11 or 12, wherein the linear cam is in the form of an elongate channel formed in or on the wall of the internal passage, the elongate channel generally having a channel length along the linear axis but sloped toward the first opening in the direction of the leading edge.

14. The lock body of any one claims 11 to 13, wherein the rotational mount is a cylindrical shaft with an axis orthogonal to the axis of the internal passage, and the rear portion of the carriage comprises corresponding radial recesses to receive the shaft.

15. The lock body of any one of the claims 11 to 14, wherein the latch assembly further comprises a link member, the link member comprising: a first end retained within the internal passage and connected to the hook member via the rotational mount, and a second end extending out of the second opening of the latch housing, wherein the link member is linearly driveable along the axis of the internal passage to move the hook member between the extended position and the retracted position.

16. The lock body of any one of claims 4 to 15, wherein the lock body is actuatable to the locked state only when the bolt is in the extended position.

17. The lock body of any one of claims 4 to 16, wherein each actuator is independently selected from the group consisting of: a push button, a hinged lever, and a rotatable lever.

18. The lock body of any one of the preceding claims, wherein: the user interface of the first lock cylinder is a keyhole and the first lock cylinder is a first key barrel operatively connected to the keyhole of the first lock cylinder, and/or the user interface of the second lock cylinder is a keyhole and the second lock cylinder is a second key barrel operatively connected to the keyhole of the second lock cylinder.