AU2017202695A1

AU2017202695A1 - Sliding Door Lock

Info

Publication number: AU2017202695A1
Application number: AU2017202695A
Authority: AU
Inventors: Peter Taylor
Original assignee: N2LOK HARDWARE TRADING Pty Ltd
Current assignee: N2LOK HARDWARE TRADING Pty Ltd
Priority date: 2016-04-26
Filing date: 2017-04-24
Publication date: 2017-11-09
Anticipated expiration: 2037-04-24
Also published as: AU2017202695B2

Abstract

A lock for a sliding door is provided which has an external lock actuator (200), including a key driven lock cylinder (2), and a latch (19) which is movable between an unlocked position and a locked position by the external lock actuator (200) or by an internal lock actuator (1). The external lock actuator (200) is operatively connected to the latch (19) by a locking mechanism that includes a sliding board (7) which is laterally offset relative to the lock cylinder (20). The locking mechanism includes a rotatable turn piece (3) coupled to the latch (19), and rotation of the turn piece (2) move the latch may be caused by operation of the external lock actuator (200) or by the internal lock actuator (1). The latch (19) includes a latch bolt (39) and other advantageous features include a hook member (37, 38) movable into an exposed position outside a surface of the latch bolt (39) when the latch bolt is in the locked position. The lock also includes a pulling plate (33) which can be used as a handle to pull a sliding door in which the lock is mounted when the door is recessed in a cavity. J D Z t o 1 1 1 2 1 3 2 7 '76 8 0 )-S 73 7 130 -74 200 2- 2 3 4 14 18~ i

Description

SLIDING DOOR LOCK

Field of the Invention [0001] The invention relates to a lock and locking mechanism, particularly of the type for use with sliding doors.

Background of the Invention [0002] Present sliding panel door locks that use a cylinder with five or more pins are bulky and the width of the entire lock mechanism including escutcheons is much larger than the width of the door on which they are located. This does not allow such locks with five or more pin cylinders to be used where a low profile lock of similar width to the door is required, such as for sliding cavity doors.

[0003] Some existing sliding panel doors locks that have a low profile use lock cylinders that have a maximum of three pins. This means that such locks are less secure than locks which use cylinders with a higher number of pins.

[0004] It would be desirable to provide a lock or locking mechanism which overcomes one or more of the problems of existing sliding door locks. For example, it may be desirable to provide a lock or locking mechanism which is secure and has a low profile. It is also desirable to provide consumers with a useful choice in selecting locks or locking mechanisms.

Summary of the Invention [0005] One aspect of the present invention provides a lock for a sliding door, comprising: an external lock actuator, including a key driven lock cylinder; a latch which is movable between an unlocked position and a locked position by actuating the external lock actuator; wherein the external lock actuator is operatively connected to the latch by a locking mechanism which is laterally offset relative to the lock cylinder.

[0006] The present invention may allow the use of longer lock cylinders, such as those with more than three pins, in less space than has previously been possible. The locking mechanism which is offset laterally compared to the lock cylinder may provide a space saving which allows the use of longer lock cylinders. Preferably, the invention will enable low profile locks to be used with sliding doors having more pins in the lock cylinder and which are therefore more secure than previously possible with sliding door locks of a low profile.

[0007] The external lock actuator is preferably positioned to allow actuation of the lock by the key of a user from an external location. For example, a keyhole may be positioned on an externally facing surface of a door in which the lock is mounted.

[0008] The lock may include an internal lock actuator which is operatively connected to the latch by the locking mechanism. The internal lock actuator may allow the lock to be actuated from an internal location, such as inside a home.

The internal lock actuator may include a manually operable rotatable member, such a turn snib, for operating the internal lock actuator. Alternatively or additionally, the internal lock actuator may be key driven similarly to the external lock actuator. Movement of the latch may be caused by operation of the external lock actuator, or by operation of the internal lock actuator, preferably by a common locking mechanism.

[0009] The locking mechanism may include a rotatable turn piece coupled to the latch such that rotation of the turn piece causes the latch to move between the unlocked position and the locked position. Rotation of the turn piece may be caused by operation of the external lock actuator, or by operation of the internal lock actuator.

[0010] The internal lock actuator may be directly or indirectly connected to the turn piece. Actuation of the internal lock actuator may directly turn the turn piece to move the latch into the locked or unlocked position. Alternatively, actuation of the internal lock actuator may indirectly turn the turn piece to move the latch into the locked or unlocked position. In other words, there may be additional parts between the internal lock actuator and the turn piece.

[0011] The external lock actuator may be indirectly connected to the turn piece. In one embodiment, a gear is provided on the rotatable turn piece which is coupled to the external lock actuator, such that operation of the external lock actuator causes rotation of the gear and turn piece causing the latch to move between the unlocked and locked positions.

[0012] The locking mechanism may include a sliding board which is laterally offset relative to the lock cylinder and which is coupled to the external lock actuator such that when a key is inserted into and turned in the lock cylinder the sliding board moves linearly to move the latch between the unlocked position and the locked position.

[0013] The sliding board may include a toothed section which interacts with the gear on the turn piece such that a linear motion of the sliding board is translated into a rotational motion of the connecting gear and turn piece [0014] The external lock actuator may include a rotatable cam. The cam may arranged to act on the sliding board, such that when a key is inserted into and turned in the lock cylinder the cam rotates to move the sliding board causing the latch to move between the unlocked position and the locked position. The cam may act directly on the sliding board in order to move the sliding board. Alternatively, the cam may act indirectly on the sliding board via another member to move the sliding board. Preferably, the mechanism is such that a rotational motion of the cam is translated into a linear motion of the sliding board.

[0015] The sliding board may be coupled to the turn piece. The sliding board may include a toothed section. The toothed section of the sliding board may interact with the connecting gear on the turn piece. The interaction between the toothed section of the sliding board and the connecting gear may be such that a linear motion of the sliding board is translated into a rotational motion of the connecting gear and turn piece.

[0016] In one embodiment, the sliding board includes a bifurcated portion having two limbs, and the cam is arranged to act on a connecting member connected to and extending between the two limbs of the sliding board.

[0017] A sliding board and cam arrangement is particularly advantageous for a space saving application, and assists in enabling a five pin lock cylinder to be used in a lock for a sliding door for added security.

[0018] The latch may include a latch bolt which is movable between an unlocked position and a locked position. In the locked position, the latch bolt may be received in a striker box mounted in the wall cavity in which the sliding door is mounted.

[0019] The latch may include a rotatable crank. The crank may be coupled to the latch bolt. The crank may be rotated to move the latch bolt between the locked and unlocked positions.

[0020] The latch bolt may be connected to the crank by a connecting rod. When the crank is actuated rotational movement of the crank may be translated by the connecting rod into lateral motion of the latch bolt to move the bolt between the unlocked and locked positions. The crank may be connected to the turn piece so that rotation of the turn piece causes rotation of the crank.

[0021] The latch may include a hook. The hook may be movable into an exposed position outside a surface of the latch bolt when the latch is in the locked position.

[0022] According to another aspect of the invention, there is provided alock fora sliding door, comprising: at least one of an external lock actuator and an internal lock actuator; a latch which is movable between an unlocked position and a locked position by actuating the external lock actuator or the internal lock actuator; the latch including a latch bolt which is movable between an unlocked position and a locked position, and wherein the latch includes a hook that is movable into an exposed position outside a surface of the latch bolt when the latch bolt is in the locked position.

[0023] In an unlocked position of the latch bolt, the hook may be contained within the body of the latch bolt.

[0024] The hook preferably protrudes from a surface of the bolt in the exposed position. The hook may be pivotally mounted within a recess in the latch bolt and may be arranged to be movable between a retracted position within the latch bolt when the latch bolt is in the unlocked position and the exposed position when the latch bolt is in the locked position.

[0025] The hook may be adapted to engage with a striker plate when the latch bolt is in the locked position.

[0026] The lock may include a pulling plate. The pulling plate may enable pushing or pulling of a sliding door in which the lock is mounted Preferably, the pulling plate acts as a handle to enable a sliding door to be pulled out from a cavity when at least the majority of the door is recessed in the cavity.

[0027] According to a further aspect of the invention, there is provided a lock for a sliding door, comprising: at least one of an external lock actuator, and an internal lock actuator; a latch which is movable between an unlocked position and a locked position by actuating the external lock actuator or the internal lock actuator; wherein the lock further includes a pulling plate which can be used as a handle to pull a sliding door in which the lock is mounted when the sliding door is recessed in a cavity [0028] The pulling plate may be part of the latch. The pulling plate may be connected to or form part of the latch bolt.

[0029] A pulling surface of the pulling plate may be positioned flat against a front face of the latch when in a stowed position. Preferably, a pulling surface of the pulling plate is located flat against a front surface of the latch bolt in the stowed position. A part of the pulling plate may be adapted to be into an active position in which the pulling plate is exposed beyond the front face of the latch. Preferably, the part of the pulling plate to be exposed may be moved out of engagement with a retaining stop, eg by lifting, and then moved into the exposed active position beyond the front face of the latch bolt.

[0030] The latch may include a resilient member. The resilient member is preferably a spring. The resilient member may urge the pulling plate into the active position when the pulling plate is moved out of engagement with a retaining stop.

[0031] The lock may include a lock cylinder having at least five pins. For example, the lock cylinder may be a 5 pin C4 cylinder. It is preferable to use a lock cylinder with more than three pins in order to create a more secure lock.

[0032] The lock may have an external escutcheon. The lock may also have an internal escutcheon. Each escutcheon may have a low profile compared to a surface of a door in which the lock is situated. It is preferable to use escutcheons with a low surface profile for aesthetic reason. Also, a low profile for the escutcheons and/or for the lock as a whole may allow the door to remain narrow and allow the door to be more easily stored in a recess or cavity.

[0033] It should be understood that the lock according to the present invention is not restricted for use with a door and may be used with sliding windows, panels or another other conceivable fixture which may use a lock of this type.

Brief Description of Accompanying Drawings [0034] The invention may be better understood by reference to preferred embodiments as shown in the accompanying drawings, in which: [0035] Figure 1 shows an exploded view of a lock according to an embodiment of the invention; [0036] Figure 2 shows an exploded view of a lock according to another embodiment of the invention; [0037] Figure 3 shows an exploded view of an embodiment of a latch suitable for use in the lock of Figure 1 or Figure 2; [0038] Figure 4A to 4C show top, front and side views of the latch of Figure 3; and [0039] Figure 5 shows an exploded view of an embodiment of a lock cylinder suitable for use in the lock of Figure 1 or Figure 2.

Detailed Description of Preferred Embodiments [0040] Figure 1 shows a first embodiment of a lock which has an external escutcheon 5 and an internal 5 escutcheon for mounting the lock in a sliding door. The escutcheons 5 and 6 have a rounded profile. Figure 2 shows an alternative embodiment which includes external and internal escutcheons 5 and 6 with a rectangular profile. The internal mechanisms of the embodiments of figures 1 and 2 are the same and they differ only in the shape of the escutcheons. Therefore, discussion of the locking mechanisms of one of the embodiments of figure 1 or figure 2 should be understood as also relating to the embodiment of the other.

[0041] These embodiments show a lock of the kind used for a sliding panel door, including an external lock actuator 200 including a lock cylinder 20 , and a latch 19 which is movable between an unlocked position and a locked position. The external lock actuator 200 is operatively connected to the latch 19 by a locking mechanism which is laterally offset relative to the lock cylinder 20. The lock cylinder 20 is mounted within a circular aperture 120 in the external escutcheon 5 [0042] The external lock actuator 200 is actuated by a key 86 being placed into a keyhole 87 in the lock cylinder 20 and turned. Turning the key 86 causes a rotation within the cylinder 20 which causes the cam 83 to rotate. A sliding board 7 is laterally offset relative to the cylinder 20. The cam 83 is operatively coupled to the sliding board 7 such that the rotational motion of the cam 83 causes a linear motion of the sliding board 7. In the embodiments shown the linear motion of the sliding board 7 will be in a vertical direction up or down, but other embodiments where the linear motion is in other directions are also possible. The sliding board 7 is operatively coupled to the latch 19 such that the linear motion of the sliding board 7 will cause the latch to move towards either a locked or unlocked position.

[0043] The lock cylinder 20 of figures 1 and 2 is shown in more detail in figure 5. Preferably, the lock cylinder 20 includes more than three pins. More preferably, the lock cylinder 20 includes at least five pins to ensure security. The lock cylinder 20 shown in figure 5 is preferably a 5 pin C4 cylinder. It will be understood that other lock cylinders may be used with different numbers of pins and in these cases the relative positioning of the various lock mechanism elements may be altered accordingly to accommodate the desired lock cylinder.

[0044] The lock cylinder 20 includes a cylinder plug 81 which has a front end face that includes a keyhole 87 into which a corresponding key 86 may be inserted. The cylinder plug 81 is rotatably mounted within a cylinder body 82 which is fixed relative to the external escutcheon plate 5 in the assembled lock. The cylinder body 82 includes an upper pin-receiving portion 97 which extends upwardly from the main cylindrical part 202 of the cylinder body 82. Cylinder lock includes five pins 204 which are received in respective bores 206 in the upper pin-receiving portion 87 of the cylinder body 82. Each pin 204 has a bottom pin 89 connected to corresponding top pin 91. The top pins 91 have the same height whereas the bottom pins 89 have different heights, each corresponding to a respective projection 216 on the key 86. Each top pin 91 is connected to a pin spring 90. The upper end of each pin spring 90 is stowed underneath a pin cover 88 and each bottom pin 89 is urged into a respective pin hole 96 of the cylinder plug 81 by its corresponding pin spring 90. When the cylinder 20 is properly assembled, the pin cover 88 will rest flat on the upper pin-receiving portion 97 such that none of the bottom pins 89, pin springs 90 and top pins 91 are outwardly visible (as seen in the cylinder 20 of figures 1 and 2). The lock cylinder 20 works such that when a key 86 is inserted in the keyhole 87 the bottom pins 89 are pushed upwards by varying amounts depending on the shape of the projections 216 on the key 86. If the key 86 is the correct shape all the bottom pins 89 will be pushed upwards out of the cylinder plug pin holes 96 which allows the cylinder plug 81 to be rotated relative to the cylinder body 82 by turning the key 86.

[0045] A rotatable cam 83 is mounted to an inner end portion 205 of the cylinder plug 81 remote from the keyhole 87. The cam 83 has a cam plate 207 and part cylindrical portions 208 which extend from the cam plate 207 into the cylinder body 82. The part cylindrical portions 208 have flat surfaces 210 which engage with corresponding flat surfaces 212 on the inner end portion of the cylinder plug 81. The cam 83 and cylinder plug 81 are held together by a cylinder clip 84 which slots into a cam indent 94 in the part cylindrical portions 208 of the cam 83 and a cylinder plug indent 93 in the cylinder plug 81. The inner end portion 205 of the cylinder plug 81 further includes wire receiving holes 92 which receive the ends of a locating wire 85 that acts to secure the cam 83 and cylinder plug 81 together.

[0046] The cam 83 and cylinder plug 81 are therefore connected together such that any rotation of the cylinder plug 81 caused by the insertion and rotation of a correct key 86 in the keyhole 87 will also cause the cam 83 to rotate.

[0047] It is understood that the foregoing description relating to figure 5 is for the 5 pin C4 cylinder shown. It is possible that the lock according to the invention could make use of an alternative lock cylinder which does not function in the described manner, but which also allows the rotation of a cam 83 to cooperate with the rest of the internal lock mechanisms to lock or unlock a latch.

[0048] The cylinder body 82 of the lock cylinder 20 is located behind the external escutcheon 5 when the lock is assembled. The front face of the cylinder plug 81 which includes the keyhole 87 will be the only part of the cylinder 20 which is externally visible when the lock is installed in a door.

[0049] Referring to Figures 1 and 2, the cylinder 20 is held in place against the rear surface of the escutcheon 5 by a fixing rack 10. The fixing rack 10 is placed around the upper portion 97 of the cylinder body 82 and screwed into position in the rear of the external escutcheon by the two screws 16. It is noted that alternative means could be used in place of the fixing rack 10 for holding the cylinder 20 in position behind the external escutcheon 5 if required.

[0050] The external lock actuator is actuated by a key 86 being placed into a keyhole 87 in the lock cylinder 20 and turned. Turning the key 86 causes a rotation within the cylinder 20 which causes the cam 83 to rotate to operate the locking mechanism.

[0051] The locking mechanism includes a sliding board 7 which is laterally offset from the lock cylinder 20 when the lock is fully assembled. The cam 83 is operatively coupled to the sliding board 7 such that the rotational motion of the cam 83 causes a linear motion of the sliding board 7. In the embodiments shown the linear motion of the sliding board 7 will be in a vertical direction up or down, but other embodiments where the linear motion is in other directions are also possible. The sliding board 7 is operatively coupled to the latch 19 such that the linear motion of the sliding board 7 will cause the latch to move towards either a locked or unlocked position [0052] The sliding board 7 has an upper portion 70 and a lower portion 74 which is bifurcated such that the upper portion 70 has two opposing limbs 71,72 connected by a bridging portion 73. Each of the limbs 71,72 has an aperture 21 and the apertures 21 are in alignment with one another. An elongate connecting member 8 having two ends is positioned between the two opposing limbs of the upper portion 70 of the sliding board 7 with one end of the member 8 located in one aperture 21 and the other end of the member 8 in the opposite aperture 21.

[0053] The lower portion 74 of the sliding board 7 has a toothed section 22 comprising a plurality of teeth 75 on the side of the sliding board 7 facing towards the lock cylinder 20. Two spaced apart notches 27 are provided on the same side of the sliding board 7 above the toothed section 22. In operation the main body portion of the sliding board 7 will be positioned against an inner part of the internal escutcheon 6. This main body portion of the sliding board 7 includes a slot 26 extending longitudinally along a portion of the length of the body of the sliding board 7.

[0054] When positioned adjacent the internal escutcheon 6, the slot 26 of the sliding board 7 receives two studs 25 (only one stud is visible in figures 1 and 2, the other is obscured by a protruding portion of the internal escutcheon 6). The studs 25 are positioned apart from each other by a distance which is less than the length of the slot 26, such that the sliding board 7 can move longitudinally along the direction of the slot 26 by a predefined amount.

[0055] The internal escutcheon 6 has a protruding circular section 28 which includes a hole through its centre that passes completely through the internal escutcheon 6. A turn snib 1 is located on the outside of the internal escutcheon 6. The turn snib 1 has a handle portion 75 for user actuation and a central cylindrical piece 30 that fits into the hole in the centre of the circular section 28 of the internal escutcheon 6 such that the handle of the turn snib 1 remains outside the front face of the internal escutcheon 6 and the circular piece 30 extends through the hole in the circular section 28 to protrude into the internal region of the lock.

[0056] A connecting gear 2 is positioned around the protruding circular section 28 of the internal escutcheon 6 and the circular piece 30 of the turn snib 1 also protrudes through the centre of the circular section 30 and engages with the connecting gear 2. This engagement of the connecting gear 2 and the circular piece 30 of the turn snib 1 means that a rotation of the handle of the turn snib 1 by a user causes a rotation of the connecting gear 2 and vice versa. The connecting gear 2 is positioned such that the teeth of the connecting gear 2 engage with the toothed section 22 of the sliding board 7. The connecting gear 2 has teeth only over a predetermined amount of the circular surface of the connecting gear 2. A gear stop 29 is positioned on the internal escutcheon 6 adjacent to the connecting gear 2 and acts to allow only a predetermined amount of rotation of the connecting gear 2 because the end teeth of the connecting gear 2 will abut the gear stop 29 when rotated by a maximum amount in the clockwise or anticlockwise direction.

[0057] A C-clip 4 is provided around an indented part of the circular piece 30 of the turn snib 1 to hold the turn snib 1 and connecting gear 2 in position in the internal escutcheon 6. The internal escutcheon 6 has four pegs 24 (only three are visible in figures 1 and 2). Two of the four pegs 24 are positioned on top of the two studs 25. A fixing plate 9 is provided which has four apertures 23 and these four apertures 23 are positioned so that each aperture 23 coincides with one of the four pegs 24. When the lock is assembled the apertures 23 of the fixing plate 9 receive the pegs 24 and the fixing plate 9 acts to keep the sliding board 7 in its correct plane to ensure that the teeth 75 of the toothed section 22 of the sliding board 7 correctly engage with the teeth of the connecting gear 2.

[0058] An elongate turn piece 3 is provided that has a cross-shaped cross section. One end of the turn piece 3 is inserted through the centre of both the connecting gear 2 and the circular piece 30 of the turn snib 1. The cross-shaped cross section of the turn piece 3 coincides wholly or partially with corresponding shaped indents in the centre of the connecting gear 2 and the circular piece 30 of the turn snib 1. This means that rotational motion of the connecting gear 2 and the turn snib 1 will also cause rotational movement of the turn piece 3 about its longitudinal axis. The other end of the turn piece 3 remote from the turn snib 1 is received in a cross shaped opening 48 in a crank 40 of a latch 19.

[0059] The cam 83 is operatively connected to the sliding board 7 so that rotational movement of the cam 83 is translated into a linear movement of the sliding board 7. Any method of translating the rotational movement of the cam 83 to a linear movement of the sliding board 7 may be used. As previously discussed, the sliding board 7 is located laterally offset from the cylinder 20. In the embodiments of figures 1 and 2, the cam surface of the cam 83 has grooves 98A, 98B which are engageable with the connecting member 8 to push the connecting member 8 downwards or upwards depending on whether a key 86 is turned in the cylinder 20 to the left or to the right. In this case, turning the key to the left or anticlockwise will cause the cam 83 to rotate anticlockwise and the upper cam surface groove 98A will push the connecting member 8 downwards which also moves the sliding board 7 in a linear downward direction. The key 86 can be moved back to its original position without further affecting the connecting rod 8 and sliding board 7 which remain in the downward position. If the key 86 is then rotated to the right or clockwise, the lower cam surface groove 98B will be rotated upwards and will act on the underside of the connecting member 8 to push the connecting member 8 upwards, hence moving the sliding board 7 linearly upwards and back to its earlier upward position. Again, the key 86 can be returned back to its original position without further affecting the position of the sliding board 7.

[0060] The lock of figures 1 and 2 further includes a pin 11 connected to a spring 12 and located in a pin retaining part 100 of the internal escutcheon 6. A cover plate 13 is placed over the pin retaining part 100 to ensure the pin 11 and spring 12 remain in place. A first end of the pin 11 includes a curved surface and a second of the pin 11 contacts an end of the spring 12. When the lock is assembled the curved end of the pin 11 pushes against the side of the sliding board 7 which has the two notches 27. When the sliding board 7 is in a raised position the pin 11 will meet the lower of the two notches 27, pushed into position by the spring 12, this feature acts to resiliently retain the sliding board 7 in the raised position when no external forces are acting. When the sliding board 7 is in a lowered position the pin will meet the upper notch 27 to resiliently retain the sliding board 7 in the lowered position when no external forces are acting.

Moving the sliding board 7 between the raised and lowered positions will cause the pin 11 to be pushed back against the spring 12 in intermediate positions until either the raised or lowered positions of the sliding board 7 is reached and the pin 11 is pushed by the spring 12 into the corresponding notch 27.

[0061] When the lock is assembled, the majority of the parts will be positioned between the two escutcheons 5, 6. The internal parts of the escutcheons are held together by protruding rods 101 of the external escutcheon 5 being positioned within partial tubes 102 of the internal escutcheon 6. Screws 17 are used through the partial tubes 102 and protruding rods 101 to hold the two escutcheons 5, 6 together in the correct position with the various lock mechanisms between them. The screw head of each of the screws 17 is accessed via the outer side of the internal escutcheon 6. It is possible that the screw heads of the screws 17 may be obscured when the lock is positioned within a door, although this feature is not necessary for the invention nor shown in the figures.

[0062] From a position where the latch 19 is unlocked, the sliding board 7 will be in a raised position maintained by the pin 11 in the lower notch 27, and cylinder plug 81 and cam 83 will be in a neutral position. Insertion and anticlockwise rotation of the key 86 in the keyhole 87 will rotate the cylinder plug 81 and cam 83 which causes the upper cam surface groove 98A to push the connecting member 8 and sliding board 7 towards a lowered position which moves pin 11 against spring 12 out of the lower notch 27. The downward linear motion of the sliding board 7 causes the toothed section 22 to move against the connecting gear 2, thus rotating the connecting gear 2 and turn piece 3. This rotation of the turn piece 3 within the opening 48 causes the crank 40 to rotate causing a bolt 39 of the latch 19 to move from an unlocked to a locked position.

[0063] We will now discuss the inner workings of the latch 19, as shown in figures 3 and 4A to 4C. The latch comprises a latch bolt 39 which is movable in a linear direction within a cylindrical latch case 32 having a mounting plate 130 at one end which is connected to a front plate 31 by screws 18. The rear end of the latch bolt 39 is connected to the rotatable crank 40 by a connecting rod 36.

[0064] The crank 40 is held in place in a crank case between an outer case plate 34 and an inner case plate 35. The crank 40 has circular portions 140 on each side of a crank arm 54. Each circular portion is received by a respective crank receiving aperture 49A, 49B in each of the outer case plate 34 and inner case plate 35. Below the crank 40 is a detent spring 47 that contacts the lower surfaces of the crank 40 and resiliently assists the crank 40 in maintaining its position. A rear end of the detent spring 47 is bent to form a hooked end part 62 that is received in a hole 63 in a rear end portion 141 of the inner case plate 35. The other end of the detent spring 47 has a flattened front end part 65 that rests on a platform 64 at the front end of the inner case plate 35. The detent spring 40 is held in position by the locations of the two end parts 62, 65, and the detent spring provides a resilient support for the crank 40.

[0065] The crank arm 54 protrudes through a crank arm -receiving hole 55 in a rear end portion 150 of the connecting rod 36. The connecting rod 36 is positioned between the outer case plate 34 and the inner case plate 35 and is guided for sliding movement relative to the crank case by projections 51 on either side of the connecting rod 36 which are located within channels 50A, 50B in each of the outer case plate 34 and the inner case plate 35. This arrangement of the crank 40 and connecting rod 36 allows rotation of the crank 40 to cause the crank arm 54 to move the connecting rod 36 forwards or backwards. The outer case plate 34 and inner case plate 35 are held together when the latch is in an assembled state by fastening tabs 144, 145 on the rear end portion 141 and on the platform 64 of the inner case plate 35 being received by corresponding receiving apertures 154,155 in the outer case plate 34.

[0066] A front end portion 151 of the connecting rod 36 is connected to the latch bolt 39. In the embodiments shown, the front end portion 151 of the connecting rod 36 has apertures 52 provided in two side portions 152, and a rear end portion 153 of the latch bolt 39 has a bolt aperture 53. A connecting rod pin 44 is threaded through the connecting rod apertures 52 and bolt aperture 53 to form the connection between the connecting rod 36 and the latch bolt 39.

[0067] The latch bolt 39, of figure 3, has an opening 155 in its upper surface leading to an internal cavity that houses a hook piece 66 which has an upper hook 37 and a lower hook 38. The hook piece 66 is pivotally mounted within the latch bolt 39 by a rotating axle 43 that passes through an aperture in the hook piece 66. When the latch bolt 39 is in a locked position in which it protrudes out of the front end of the latch case 32, a hook spring 46 biases the upper hook 37 upwardly to protrude from the opening 156 in the upper surface of the latch bolt 39, as shown in figure 4B. When the latch is in an unlocked position, the latch bolt 39 is stowed in the latch case 32 which prevents the upper hook 37 from outwardly protruding from the latch bolt 39.

[0068] The latch when installed in a door will be positioned such that the front plate 31 is on the side of a sliding door which is to be brought together with and locked against an opposing wall. The opposing wall will have a striker box 15 installed that has a striker plate 14 attached to an outward face of the striker box 15 by further screws 118.

[0069] When a sliding door is to be locked in a closed position, the door is slid shut such that the striker plate 14 and front plate 31 are touching or in close proximity. The locking mechanism of the lock can be actuated which will cause the bolt 39 to protrude from the surface of the front plate 31 and into the striker box 15. The upper hook 37 will be pushed upwards by the hook spring 46 when the latch bolt 39 is released, and the upper hook 37 will positively lock behind a corresponding angled projection 164 of the striker plate 14 to securely fasten the door in place and prevent opening of the door without unlocking the lock.

[0070] Figures 4A, 4B and 4C show an embodiment of the described latch assembled and placed in the locked position with the latch bolt 39 protruding from the latch case, upper hook 37 protruding outwards and the crank arm 54 in the forward position.

[0071] In some situations sliding panel doors are located within wall cavities when the doors are in an open position. In these situations it can be more difficult to close the door because obtaining a grip on the door panel within the cavity can be difficult. The embodiments shown in the accompanying drawings have a feature which allows a sliding door with the latch fitted to be gripped and pulled from the cavity.

[0072] As shown in figure 3, a pulling plate 33 is positioned on the front surface of the latch bolt 39. The pulling plate 33 has front end part 160 with two side parts 161, 162 that are received in side channels 163 on either side of the latch bolt 39. The pulling plate 33 is slidably connected to the latch bolt 39 by means of a rivet 45 which passes through rivet holes 57 in the side parts 161,162 of the pulling plate 33 and rivet channels 56 on either side of the latch bolt 39.

The pulling plate 33 further has protuberances 59 on the inner surfaces of the two side parts 161,162 of the pulling plate 33 which rest on the lower surfaces of slots 58 on the sides of the latch bolt 39. Behind the protuberances 59 in the slots 58 are sliding pieces 41 A, 41B which are connected to springs 42A, 42B which act on the sliding pieces to bias the front end part 160 of the pulling plate 33 away from the front face 165 of the latch bolt 39. The pulling plate 33 is held in the position adjacent the front face 165 of the latch bolt 39 and normally prevented from sliding forwardly from the latch bolt 39 by the interaction between a bolt stop 60 and a pulling plate stop 61. However, as seen in figure 4B, there is a gap 67 between the upper surfaces of the pulling plate 33 and the upper surfaces of the front ends of the side channels 163 of the latch bolt 39 which allows the front end part 160 of the pulling plate 33 to be lifted so that the bolt stop 60 and pulling plate stop 61 no longer engage and the pulling plate 33 is released and pushed outwardly by the springs 42A, 42B acting on the sliding pieces 41 A, 41B. In this case, when lifting the front end part 160 of the pulling plate 33, the rivet 45, connecting the rivet holes 57 of the pulling plate 33 and rivet channels 56 of the bolt 39, acts as a pivot to allow the front face to be lifted.

[0073] When the pulling plate 33 is pushed outwards from the front face of the bolt 39 it may be used as a handle to pull a door when located within a wall cavity. The pulling plate 33 may be returned to its position adjacent the front face of the bolt 39 by pushing the pulling plate 33 inwards until the bolt stop 60 and pulling plate stop 61 re-engage.

[0074] It should be understood that the foregoing description relates to preferred embodiments of the invention only and that there are many other embodiments not directly referred to that will be encompassed by the invention in its broadest scope. Items described above may be replaced by equivalent elements that perform a similar function providing that these are encompassed within the broadest scope of the invention. For example, a lock according to the invention may incorporate an alternative latch that does not have the same features as the described latch or may only have some of the features in common.

[0075] The described lock mechanism allows the use of a 5 pin C4 lock cylinder within a low profile sliding door lock. The low profile of the door means that the width of the lock from the outermost face of the internal escutcheon to the outermost face of the external escutcheon is substantially similar to the width of the door. This is particularly of assistance for use with sliding doors which are located within a wall cavity when the door is opened fully as the wall cavity only needs to be partially wider than the door width.

Drawing Reference Numerals: 1 Turnsnib 2 Connecting gear 3 Turn piece 4 C-clip 5 External escutcheon 6 Internal escutcheon 7 Sliding board 8 Connecting member 9 Fixing plate 10 Fixing rack 11 Pin 12 Spring 13 Cover plate 14 Striker plate 15 Striker box 16 First screws 17 Second screws 18 Third screws 19 Latch 20 Cylinder 21 Sliding board aperture 22 Toothed section 23 Fixing plate apertures 24 Peg 25 Stud 26 Sliding board slot 27 Sliding board notch 28 Protruding circular section 29 Gear stop 30 Cylindrical piece of turn snib 31 Front plate 32 Latch case 33 Pulling plate 34 Outer case 35 Inner case 36 Connecting rod 37 Upper hook 38 Lower hook 39 Latch bolt 40 Crank 41 A, 41B Sliding piece 42A, 42B Sliding piece spring 43 Rotating axle 44 Connecting pole pin 45 Rivet 46 Hook spring 47 Detent spring 48 Opening 49A, 49B Crank receiving aperture 50A, 50B Case channel 51 Projection 52 Connecting pole aperture 53 Bolt aperture 54 Crank arm 55 Crank arm-receiving hole 56 Rivet channel 57 Rivet holes 58 Bolt slot 59 Protuberance 60 Bolt stop 61 Pulling plate stop 62 Hooked end 63 Hole 64 Platform 65 Flattened portion 66 Hook piece 67 Gap 70 Upper portion of sliding board 71,72 Limbs of upper portion 73 Bridging portion 74 Lower portion of sliding board 75 Teeth on sliding portion 76 Handle portion of turn snib 81 Cylinder plug 82 Cylinder body 83 Cam 84 Cylinder clip 85 Locating wire 86 Key 87 Keyhole 88 Pin cover 89 Bottom pin 90 Pin spring 91 Top pin 92 Wire receiving hole 93 Cylinder plug indent 94 Cam indent 95 Cam aperture 96 Cylinder plug pin hole 97 Upper portion of cylinder body 98A, 98B Cam surface groove 100 Pin retaining part 101 Protruding rods of external escutcheon 102 Partial tubes of internal escutcheon 120 Circular aperture in external escutcheon 130 Mounting plate of latch case 140 Circular portions on crank arm 141 Rear end portion of inner case plate 144, 145 Fastening tabs on inner case plate 150 Rear end portion of connecting rod 151 Front end portion of connecting rod 152 Side portions of connecting rod 154,155 Tab-receiving apertures 156 Opening in latch bolt 160 Front end part of pulling plate 161,162 Side parts of pulling plate 163 Side channels on latch bolt 164 Angled projection on striker plate 165 Front face of bolt 200 External lock actuator 202 Cylindrical part of cylinder body 204 Pins of lock 205 Inner end portion of cylinder body 206 Bores in cylinder body 207 Cam plate 208 Part cylindrical portions of cam 210 Flat surfaces on cam portions 212 Flat surfaces on inner end portion of cylinder plug 216 Projections on key

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A lock for a sliding door, comprising: an external lock actuator, including a key driven lock cylinder; a latch which is movable between an unlocked position and a locked position by actuating the external lock actuator; wherein the external lock actuator is operatively connected to the latch by a locking mechanism which is laterally offset relative to the lock cylinder.
2. A lock according to claim 1, including an internal lock actuator which is operatively connected to the latch by the locking mechanism.
3. A lock according to claim 1 or claim 2, wherein movement of the latch may be caused by operation of the external lock actuator or by operation of the internal lock actuator.
4. A lock according to any one of the preceding claims, wherein the locking mechanism includes a rotatable turn piece coupled to the latch such that rotation of the turn piece causes the latch to move between the unlocked position and the locked position .
5. A lock according to claim 4 as appended to claim 2, wherein rotation of the turn piece may be caused by operation of the external lock actuator or by operation of the internal lock actuator.
6. A lock according to any one of the preceding claims, wherein the latch includes a latch bolt which is movable between an unlocked position and a locked position .
7. A lock according to claim 6, wherein a rotatable crank is coupled to the latch bolt such that rotation of the crank causes the latch bolt to move between an unlocked position and a locked position.
8. A lock according to claim 7, wherein the latch bolt is connected to the crank by a connecting rod, and rotational movement of the crank is translated into lateral motion of the latch bolt to move the latch bolt between the unlocked position and the locked positions.
9. A lock according to claim 7 or claim 8 as appended to claim 4, wherein the rotatable crank is connected to the turn piece, so that rotation of the turn piece causes rotation of the crank.
10. A lock according to claim 4 or claim 5, or any one of claims 6 to 9 as appended to claim 4 or claim 5, wherein a gear is provided on the rotatable turn piece which is coupled to the external lock actuator, such that operation of the external lock actuator causes rotation of the gear and the turn piece causing the latch to move between the unlocked position and the locked position.
11. A lock according to any one of the preceding claims, wherein the locking mechanism includes a sliding board which is laterally offset relative to the lock cylinder and which is coupled to the external lock actuator such that when a key is inserted into and turned in the lock cylinder the sliding board moves linearly to move the latch between the unlocked position and the locked position
12. A lock according to claim 11 as appended to claim 10, wherein the sliding board includes a toothed section which interacts with the gear on the turn piece such that a linear motion of the sliding board is translated into a rotational motion of the connecting gear and turn piece.
13. A lock according to claim 11 or claim 12 wherein the external lock actuator includes a rotatable cam which is arranged to act on the sliding board, such that when a key is inserted into and turned in the lock cylinder the cam rotates to move the sliding board causing the latch to move between the unlocked position and the locked position.
14. A lock according to claim 13, wherein the sliding board includes a bifurcated portion having two limbs, and the cam is arranged to act on a connecting member connected to and extending between the limbs of the sliding board.
15. A lock according to any one of the preceding claims, wherein the lock cylinder has at least five pins, and is preferably a 5 pin C4 cylinder.
16. The lock according to any one of the preceding claims, wherein the lock has an external escutcheon and an internal escutcheon, and each escutcheon has a low profile compared to a surface of a door in which the lock is mounted.
17. A lock according to any one of the preceding claims, wherein the lock has an external escutcheon and an internal escutcheon, and each escutcheon has a low profile compared to a surface of a door in which the lock is mounted.
18. A lock according to any one of claims 6 to 9, wherein the latch includes a hook that is movable into an exposed position outside a surface of the latch bolt when the latch bolt is in the locked position.
19. A lock for a sliding door, comprising: at least one of an external lock actuator, and an internal lock actuator; a latch which is movable between an unlocked position and a locked position by actuating the external lock actuator or the internal lock actuator; the latch including a latch bolt which is movable between an unlocked position and a locked position, and wherein the latch includes a hook that is movable into an exposed position outside a surface of the latch bolt when the latch bolt is in the locked position.
20. A lock according to claim 18 or claim 19, wherein the hook is adapted to engage with a striker plate when the latch bolt is in the locked position.
21. A lock according to any one of claims 18 to 20, wherein the hook is pivotally mounted within a cavity in the latch bolt, and is movable between a retracted position within the latch bolt and the exposed position when the latch bolt is in the locked position.
22. A lock according to any one of the preceding claims, wherein the lock further includes a pulling plate which can be used as a handle to pull a sliding door in which the lock is mounted when the door is recessed in a cavity.
23. A lock for a sliding door, comprising: at least one of an external lock actuator, and an internal lock actuator; a latch which is movable between an unlocked position and a locked position by actuating the external lock actuator or the internal lock actuator; wherein the lock further includes a pulling plate which can be used as a handle to pull a sliding door in which the lock is mounted when the door is recessed in a cavity.
24. A lock according to claim 22 or claim 23, wherein latch includes a latch bolt which is movable between an unlocked position and a locked position, and the pulling plate is part of the latch bolt.
25. A lock according to claim 24, wherein the pulling plate has a front surface which is positioned flat against a front face of the latch bolt when in a stowed position, and the pulling plate is adapted to be moved into an active position in which the pulling plate is exposed beyond the front face of the latch.
26. A lock according to claim 25, wherein the latch includes a stop for retaining the pulling plate in the stowed position, and a resilient member, preferably a spring, which urges the pulling plate into the active position when the pulling plate is moved out of engagement with the retaining stop.