AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Invention Title: Assa Abloy Australia Pty Limited Applicant: A Latch and Latchset The invention is described in the following statement: -2 TECHNICAL FIELD The invention described herein generally relates to a latchset and, more particularly, is concerned with a latchset which includes a retractable handle, the operation of which causes a latch to move between a locking or latched position and an unlocking or unlatched position although the scope of the invention is not necessarily limited thereto. BACKGROUND ART A sliding door or window is typically moved, relatively to a frame to which the door or window is slidingly mounted, by way of a handle which is secured to the door or window. The handle normally projects from a side of the door or window so that a user can grab the handle when operating the door or window such as by opening or closing the door or window. As a result of the handle extending from a side of the door or window, the handle can be an obstruction which may result in a user bumping into the handle or a piece of clothing of the user catching onto the handle. This may be painful and undesirable. Various attempts have been made to provide the door or window with a mechanism through which the door or window can be operated relatively to the frame but which reduces the likelihood of the mechanism being an obstruction. For example, a recess can be formed into a side of the door or window and against which the user can grab when the door or window is moved relative to the frame. SUMMARY OF THE INVENTION According to an aspect of the invention, there is provided a latchset which includes an assembly and a strike; the assembly including a latch which can be pivotally moved between a latched position and an unlatched position, and a handle which can be moved between an extended position at which the handle projects at least partly from the assembly and a retracted position at which the handle is at least partly withdrawn into the assembly; and wherein movement of the handle to the retracted position causes the latch to move to the latched position so that the assembly can be secured to the strike when the assembly is positioned adjacent the strike. According to another aspect of the invention, there is provided a latch apparatus which includes a first housing, a second housing, a handle which can be moved between an extended position and a retracted position, an actuator, a reciprocating drive chassis for mounting the handle relative to the first housing and which is moveable between a free position and an - 3 engaged position at which the reciprocating drive chassis is engaged with the actuator, a latch which is rotatably mounted to the second housing, and a latch drive plate which is associated with the latch and with the reciprocating drive chassis; the reciprocating drive chassis is biased towards the free position; movement of the latch drive plate causes movement of the latch between a latched position at which the latch extends at least partly from the second housing and an unlatched position at which the latch is withdrawn at least partly into the second housing, and wherein the latch drive plate, the reciprocating drive chassis and the handle interengage such that movement of the handle towards the retracted position causes the reciprocating drive chassis to move to the engaged position and the latch to move to the latched position, and operation of the actuator causes the reciprocating drive chassis to be released to move to the free position thereby causing the handle to move to the extended position and the latch to the unlatched position. Typically the first housing and the second housing are oriented substantially perpendicularly to each other such that the first housing is mounted in a sidewall of a window member for example, and the second housing is mounted in an end wall of the window member. A connecting member extending from the latch drive plate preferably extends through an opening in the first housing and engages with the drive chassis to provide interengagement between the latch drive plate, the drive chassis, the handle and the actuator. The movement of the handle to the retracted position reduces the likelihood of the handle being an obstruction, for example to a user. Additionally, the movement of the handle into the assembly, and thereby into a side of a door or window to which the assembly is mounted, may improve the overall appearance and ascetic appeal of the door or window since an outer surface of the handle is substantially planar with an outer surface of a faceplate or of a portion of the door or window which surrounds the handle if no faceplate is used. Consequently, the handle does not extend from the side of the door or window at least when the door or window is not being operated by the user. Movement of the handle to the extended position may cause the latch to move to the unlocking position. The handle may be automatically moved to the extended position through the operation of an actuator. The assembly may further include a mechanism which prevents the latch from being moved to the locking position if the assembly is not positioned adjacent to the strike. The mechanism may further prevent the handle from being moved to the retracted position substantially at the same time when the latch is being moved to the locking position.
- 4 The assembly may include a first housing to which the handle is movably mounted, and a second housing to which the latch is movably mounted. The first and second housings may be integrally formed or may be formed separately. In the latter instance the first and second housings may be associated with each other in any suitable way so that the movement of the handle between the extended and retracted positions causes movement in the latch between the locking and unlocking positions. Alternatively the assembly may be contained only in a first housing so that the handle extends from a side of the first housing when in the extended position and the latch extends from an end of the first housing when in the locking position. The handle and the latch, when respectively in the extended and locking positions, may extend from the assembly perpendicularly relatively to each other. The assembly may be secured to an enclosure, for example a door or a window which may be pivotally or slidingly attached to a frame, in any appropriate way such as by using screws, a plurality of nuts and bolts, rivets or the like. In one embodiment, the first housing is secured to a side of the enclosure and the second housing to an end of the enclosure. The first housing may be secured at a position on the enclosure which is adjacent to a position at which the second housing is secured to the enclosure. Alternatively, the first housing may be secured to the enclosure at a suitable position, for example halfway between upper and lower ends of the enclosure, and the second housing may be secured to the enclosure at a position at which the second housing is remote from the first housing, for example in close proximity to either of the upper or lower ends. According to one embodiment of the invention, the assembly includes, associated with the first housing, a drive chassis to which the handle is slidingly mounted for movement between the extended and retracted positions and which is movable between an upper position and a lower position, a biasing member which biases the drive chassis towards the lower position, and an actuator with which the drive chassis engages when the drive chassis is at the upper position so that the drive chassis is retained in the upper position and which is operable to allow the drive chassis to move under the biasing force of the biasing member to the lower position, and wherein movement of the handle to the retracted position causes the drive chassis to move to the upper position, and wherein movement of the drive chassis to the lower position causes the handle to move to the extended position. The handle may be slidingly mounted to the drive chassis using any appropriate technique. In one embodiment of the invention, the handle may include a first pair of spaced -5 apart spigots at one end of the handle and/or a second pair of spaced apart spigots at an opposed end of the handle. The drive chassis may include two pairs of spaced apart channels at suitable locations so that each pair of spigots can be engaged with a respective pair of channels. Each channel may be formed into a respective side wall of the drive chassis at a suitable position so that the handle is guided through the movement of the first and second pairs of spigots inside the respective pairs of channels between the extended and retracted positions. Each of the channels may extend across an inner surface of the respective side wall at an angle relatively to a base portion of the first housing so that longitudinal movement of the drive chassis between the upper and lower positions causes transverse movement of the handle relatively to the drive chassis between the extended and retracted positions. The first housing may include a first pair of spaced apart guide formations and a second pair of spaced apart guide formations each of which is formed in a side wall of the first housing at a suitable position so that the transverse movement of the handle between the extended and the retracted positions is further guided by the guide formations in the housing. In this example, each channel extends through the respective sidewall of the drive chassis so that each spigot of the pairs of spigots can extend through the respective channel into the respective guide formation. Therefore, movement of the handle transversely (into and out of the first housing) causes the drive chassis to reciprocate due to the angled channels in the drive chassis. The drive chassis may be integrally formed or may be assembled from a first part and a second part which are fitted to each other using any suitable technique such as using complimentary formation which allow the first and second parts to be correctly mated with each other. Alternatively, a cavity formed inside the first housing may be suitably dimensioned so that the first and second parts, once fitted to each other, can be inserted into the cavity so that the fitment of the first and second parts to each other is maintained but also allowing longitudinal movement of the drive chassis between the upper and lower positions. The first and second parts may be secured to each other, for example by using glue, fasteners, sonic welding or the like. In one embodiment the handle is first fitted to the first and second parts before the parts are fitted to each other. In this instance the first and second pairs of spigots are placed in the respective pairs of channels before the first and second parts are fitted to each other. The assembly may further include a cover plate which can be secured to the first housing and which retains the handle, the actuator, and the drive chassis inside the cavity -6 formed inside the first housing. In one embodiment of the invention the cover plate is used to secure the first housing, for example, to the door or window by using suitable clips. In a different embodiment, suitable fasteners are used to secure the cover plate to the door. The handle may be movable between the extended and retracted positions through an aperture which is formed through the cover plate. The assembly may further include a key cylinder which is associated with the first housing and which is operable between a locked configuration in which movement of the drive chassis to the lower position is prevented and an unlocked configuration in which movement of the drive chassis to the lower position is allowed. In one embodiment of the invention, the key cylinder includes a shoulder against which a lower end of the drive chassis abuts when the drive chassis is in the upper position. Consequently, the drive chassis cannot be moved to the lower position through the biasing force of the biasing member when the actuator is operated until the shoulder is moved by operation of the key cylinder. The biasing member which biases the drive chassis towards the lower position may be associated in any appropriate way with the assembly so that the drive chassis is biased in this way. In one example the biasing member is an extension spring which is secured at one end to the drive chassis and at an opposed end to the first housing. Any suitable technique can be used to secure the biasing member respectively to the drive chassis and to the first housing. In one embodiment of the invention, the extension spring includes a first eyelet at one end and a second eyelet at an opposed end of the extension spring. The drive chassis includes a first formation or drive chassis anchor and the first housing may include a second formation or housing anchor. The first eyelet is secured to the drive chassis anchor and the second eyelet is secured to the first housing anchor. The operation of the actuator may cause the actuator to move relatively to the assembly in any appropriate way, for example pivotally or slidingly. In one example the actuator is a button which is movably mounted inside the first housing for longitudinally movement between a retaining position at which the drive chassis is retained in the upper position and a releasing position at which the drive chassis is released so that the drive chassis can be moved under the biasing force of the biasing member towards the lower position. A biasing member, for this example a compression spring, may be positioned between the button and the first housing so that the button is biased towards the retaining position. In one example the compression spring is positioned between an operative end of the button and the first housing.
-7 Thus, the button is moved against the biasing action of the compression spring towards the releasing position. The positioning of the shoulder relatively to the lower end of the drive chassis may be such so that when the actuator is operated, the drive chassis is kept at a position relatively to the actuator by the interaction of the shoulder with the lower end so that the drive chassis is still retained in the upper position by the actuator if the key cylinder is in the locked configuration. Any suitable technique may allow the actuator to retain the drive chassis in the upper position, such as mechanical, electrical, magnetic or the like. In one embodiment of the invention, the actuator may further include a first hook formation which is associated with the operative end and the drive chassis may include a second hook formation with which the first hook formation engages when the drive chassis is in the upper position and the actuator is in retaining position. This formation may be formed partly by the first part of the drive chassis and partly by the second part of the drive chassis. Any suitable arrangement or technique may be used to cause the latch to move between the locking and unlocking positions when the handle is moved between the retracted and extended positions such as mechanical or electrical. In one embodiment of the invention, the assembly includes, associated with the second housing, a mechanism which includes a latch drive plate which has a connecting member and which causes the latch to move between the locking and unlocking positions, and a stop member which is movable between a first position at which the latch drive plate is prevented from moving the latch to the locking position and a second position at which the latch is movable to the locking position; and wherein the connecting member connects the latch drive plate to the drive chassis so that movement of the drive plate chassis between the upper and lower positions causes the latch to move between the locking and unlocking positions. The connecting member may extend through the first housing so that a free end of the connecting member is located inside the drive chassis. The first housing may include a suitable aperture which may be formed in one or in both of the side walls of the first housing thereby allowing the connecting member to extend into the drive chassis. The aperture may be suitable dimensioned to allow the drive chassis, and consequently the latch drive plate, to be moved freely between the engaged and disengaged positions. The free end of the connecting member may tightly engaged with the drive chassis or, alternatively, may by loosely fitted inside a chamber which is formed inside the drive -8 chassis and which may be defined at an upper end and a lower end respectively by a suitable wall member. The latch may include a cylindrical member and a hook member which extends radially from the cylindrical member so that hook member rotates about a central axis of the cylindrical member. The hook member has a hook portion which extends transversely from the hook member so that the hook portion lies in a plane in which the cylindrical member lies. The cylindrical member may include a spigot which extends at a position which is off centre and on one side of the latch. The latch drive plate is formed with a groove formation into which the spigot extends and which is movable between an engaged position at which the latch is moved to the locking position and a disengaged position at which the latch is moved to the unlocking positions. The spigot acts against a lower portion of the groove formation when the latch drive plate is moved to the engaged position so that the spigot is rotated in a first direction about the central axis of the cylindrical member thereby causing the latch to rotate about the central axis of the central body so that the latch is pivoted to the locking position. Conversely, the spigot acts against an upper portion of the groove formation when the latch drive plate is moved to the disengaged position so that the cylindrical member is rotated in a second, opposite direction about the central axis of the cylindrical member thereby moving the latch to the unlocking position. The stop member may be in the form of a pin which is longitudinally movable inside a passage which extends party into the second housing from an outer end of thereof. The pin may be biased to the first position in any appropriate way. In one embodiment of the invention, a compression spring is positioned between an inner end of the pin and the second housing so that the pin is moved against the biasing force of the spring to the second position. The pin may be prevented from being pushed from the second housing by the compression spring in any appropriate way. In one example, the inner end includes a collar which extends partly or wholly around the pin and which acts against part of the second housing which defines a hole in the outer end and from which the pin projects when in the first position. The latch drive plate may be prevented from moving the latch to the locking position in any suitable way such as by preventing rotational movement of the latch from the unlocking position to the locking position. In one embodiment or the invention, the latch drive plate includes a member which extends from an upper end of thereof and which lies adjacent or which abuts the collar of the pin so that the latch drive cannot be moved to the engaged -9 position when the pin is in the first position. However, when the pin is moved to the second position, the collar is displaced transversely relative to the member so that a free end of the member can be moved past the collar. In one embodiment of the invention, the free end of the member is moved out of the path of the pin so that the pin can extend over the member. In a different embodiment, the free end extends through a passage which is made through the pin. Typically, the pin is mounted relative to the second housing and biased outwardly such that the pin will make contact with the strike before the face plate abuts the strike. Once the pin makes contact with the strike, further movement of the second housing toward the strike will typically depress the pin, forcing the pin into the second housing against the biasing force. Abutment of the second housing with the strike will therefore preferably cause the pin to be moved to a second position, allowing the latch drive plate free movement which in turn allows operation of the actuator to cause the handle to move to the extended position and the latch to move to the latched position. The second housing may include a cover plate which is integrally formed with the second housing during the manufacture thereof or which is secured to the housing using any suitable technique such as fasteners, gluing, sonic welding or the like. In one embodiment of the invention, the latch extends through the cover plate when in the locking position and the pin projects from the cover plate when in the first position. The strike may have any suitable profile to allow the latch to engage with a portion thereof when the latch is in the locking position. In one embodiment of the invention, the strike has a cavity which is profiled so that the hook portion of the latch can clip onto the strike when the latch is in the locking position. The strike may further include a projection which extends from an operative side of the strike. The cover plate may include a locating recess which is formed into the outer end of the second housing and with which the projection can be registered thereby ensuring, at least to some extent, correct alignment of the second housing relative to the strike and vice versa. According to a different aspect of the invention, there is provide A latchset which includes an assembly and a strike; the assembly including a first housing and a second housing, a reciprocating drive chassis which is movably mounted to the first housing for movement between a free position and an engaged position, a handle which is movably mounted to the first housing through the reciprocating drive chassis and which can be moved between an extended position at which the handle extends at least partly from the first housing and a retracted position at which the handle is at least partly withdrawn into the first - 10 housing, a latch which is pivotally mounted to the second housing and which can be moved between a latched position at which the latch extends at least partly from the second housing and an unlatched position at which the latch is withdrawn at least partly into the second housing, an actuator which causes the reciprocating drive chassis to move from the engaged position to the free position thereby causing the handle to move to the extended position, and a mechanism which includes a stop member which can be moved between a first position at which movement of the latch to the latched position is prevented and a second position at which the latch can be moved to the latched position; and wherein abutment of the second housing with the strike causes the stop member to be moved to the second position thereby allowing the operation of the actuator to cause the handle to move to the extended position and the latch to move to the latched position. In another embodiment of the invention, the strike includes a first plate and a second plate which are fitted to each other so that the cavity is formed between the two plates. Suitable fasteners may be used to secure the first and second plates to each other or to secure the second plate to a frame structure with the first plate positioned between the frame structure and the second plate thereby securing the first and second plates to each other. According to another aspect of the invention, there is provided a method of operating a latchset which includes an assembly and a strike, the assembly including a handle which is movable between an extended position at which the handle projects at least partly from the assembly and a retracted position at which the handle is at least partly withdrawn into the assembly, a latch which is movable between a latched position at which the latch extends at least partly from the assembly and an unlatched position at which the latch is at least partly withdrawn into the assembly, an actuator the operation of which causes the handle to be moved to the extended position and the latch to the unlatched position, and a mechanism which prevents the latch from being moved to the latched position when the assembly is not adjacent the strike; the method including the steps of, when the assembly is adjacent the strike, operating the actuator so that the handle is caused to be moved to the extended position which causes the latch to be moved to the unlatched position so that the assembly can be moved relatively to the strike; and, after the assembly has been returned to a position at which the assembly is adjacent to the strike so that the mechanism does not prevent the latch from being moved to the latched position, moving the handle to the retracted position thereby causing the latch to move to the latched position.
- 11 BRIEF DESCRIPTION OF THE DRAWINGS The invention is now described, by way of example only, with reference to the drawings. The following description is not intended to limit the scope of the preceding summary or the claims. Figure 1 contains a perspective view of a latchset according to the invention which is fitted to a frame member of a door. Figure 2 is a perspective view of a first housing of an assembly of the latchset in which components of the first housing are shown in an exploded configuration. Figure 3 is a perspective view of a second housing of the assembly in which the components of the second housing are shown in an exploded configuration. Figures 4 to 6 are cross sectional side views of the first housing in which the various stages of operation of the components of the first housing are shown. Figure 7 and 8 are plan views of the first and second housing which are mounted to a frame member and in which the different positioning of the second housing relative to the first housing is shown. Figure 9 is a perspective view, in cross section, showing the engagement of the second housing with a strike of the latchset. DESCRIPTION OF ILLUSTRATED EMBODIMENT Figure 1 of the accompanying representations illustrates a latchset 10 according to the invention which includes an assembly 12 and a strike 14 which is shown in Figure 9. The latchset is secured to a frame member 16 of an enclosure 18 such as a door or a window. The door 18 is movably mounted to a frame, not shown, and is movable relative to the frame so that an aperture defined by the frame is covered by the door or open. Figures 2 and 3 show in greater detail the various components of the assembly 12. In Figure 2 a first housing 20 of the assembly is shown and in Figure 3 a second housing 22 of the assembly is shown The assembly includes, associated with the first housing 20, a drive chassis 24 which is slidingly mounted to the first housing 20 for movement between an upper, engaged position 26 - 12 (see Figure 4) and a lower, free position 28 which is shown in Figure 6, a biasing member or extension spring 30 which biases the drive chassis towards the lower position, an actuator or button 32 with which the drive chassis is engaged when the drive chassis is at the upper position so that the drive chassis is retained in the upper position by the button, and a handle 34 which is movably mounted to the drive chassis for movement between a retracted position 36 which is shown in Figure 4 and an extended position 38 which is shown in Figure 6. The handle 34 is slidingly mounted to the drive chassis 24 through a number of spigots in which our slidingly engaged in a number of channels formed in the drive chassis. The handle has a first pair of spaced apart spigots 40 at one end of the handle and a second pair of spaced apart spigots 42 at an opposed end of the handle. The drive chassis has a first pairs of spaced apart channels 44 and a second pair of spaced apart channels 46 which is formed in the drive chassis a predetermined distance away from the first pair of spaced apart channels so that each pair of spigots can engage with a respective pair of channels. Each channel of the first and second pairs of channels 44 and 46 is formed into a respective side wall 48 of the drive chassis and extends across the respective and inner surface 50 of the respective side wall at an angle 52 relatively to a base portion 54 of the first housing 20 so that longitudinal movement of the drive chassis inside a cavity 56 of the drive chassis between the upper and lower positions 26 and 28 results in a transverse movement of the handle 34, relatively to the drive chassis, between the retracted an extended positions 36 and 38. The movement of the handle 34 between the retracted and extended positions 36 and 38 is further guided by suitable formations formed in the first housing 20. Each channel of the first and second pairs of channels extends through the respective sidewall 48 so that each spigot of the first and second pairs of spaced part spigots project from the drive chassis. The first housing 20 has a first pair of guide formations 58 and a second pair of spaced apart guide formations 60. The first and second pairs of guide formations are formed at suitable positions in a respective side wall 62 of the first housing so that a respective spigot of the first and second pairs of spaced apart spigots 40 and 42 is registered with a respective guide formation of the first and second pairs of guide formations 58 and 60. Thus, movement of the handle 34 between the retracted and extended positions 36 and 38 is guided via the first and second pairs of spaced apart guide formations 58 and 60. The drive chassis 24 is assembled from a first part 64 and a second part 66 which is fitted to each other through a series of interlocking formations 68 so that positioning of the first - 13 and second parts relatively to each other is promoted. A suitable fastener, not shown, can be threadedly engaged with a shank 70 through a hole 72 which is formed through the sidewall 48 of the drive chassis so that the second of the first and second parts can be secured to each other. The cavity 56 of the first housing 20 is suitably dimensioned so that the drive chassis is insertable into the cavity with little transverse play of the drive chassis inside the cavity. The assembly 12 includes a cover plate 74 which is secured to the frame member 16 so that the handle 34, the drive chassis 24 and the button 32 is movably retained inside the cavity 56. The first housing 20 has a pair of shoulder formations 76 each of which rests on a respective portion 78 of an outer surface 80 of the frame member 16 when the first housing is inserted into a cavity 82 which is formed into the frame member (see Figure 1). Thus, the cover plate, once secured to the frame member, maintains the first housing, including all of the components fitted to the first housing, in position relatively to the frame member. The assembly 12 further includes a key cylinder 84 which is fitted to the cover plate 74 so that an inner end 86 of the key cylinder is located inside the cavity 56 of the first housing 20. The cover plate has a suitable hole 88 into which the key cylinder is insertable before the key cylinder is secured to the cover plate, for example by using a circlip or by engaging a portion of the key cylinder with a portion of the hole. An upper end of the key cylinder carries a shoulder formation which rests against a recess which extends around a mouth of the hole 88. This ensures that the key cylinder extends to a predetermined depth into the cavity 56 of the first housing. The key cylinder is operable between a locked configuration 90 which is shown in Figure 4, and an unlocked configuration 92 which is shown in Figure 6. The key cylinder has a shoulder 94 which abuts a lower end 96 of the drive chassis when in the key cylinder is in the locked configuration so that movement of the drive chassis from the upper position 26 to the lower position 28 is prevented. When the key cylinder is moved to the unlocked configuration, the shoulder is moved to a position relatively to the lower end of the drive chassis so that the lower end can move past the inner end 86 thereby allowing the drive chassis to be moved to the lower position through the biasing force of the extension spring 30. The extension spring 30 has a first eyelet 100 at one end and a second eyelet 102 at an opposed end at an opposed end. The shank 70 of the drive chassis 24 acts as a drive chassis anchor 104 to which the first eyelet is engaged. The first housing 20 has a housing anchor 106 to which the second eyelet is engaged.
- 14 The button 32 is movable between a retaining position 108, which is shown in Figure 4, and a releasing position 110 which is shown in Figure 5. An inner or operative end 112 carries a first hook formation 114 which can be engaged with a second hook formation 116 which is formed at an upper end 118 of the drive chassis 24. The second hook formation is formed as a result of the fitment of the first and second part 64 and 66 of the drive chassis. In other words, one half of the second hook formation is carried by the first part 64 of the drive chassis and the other half of the second hook formation is carried by the second part 66 of the drive chassis. A biasing member or compression spring 120 is positioned between the operative end 112 and the first housing 20 which is formed with a spigot 122 on to which the button is fitted so that the spigot is longitudinally moved inside a cavity 124, which extends partly into the button from the operative end, when the button is moved between the retaining and releasing positions 108 and 110. The compression spring 120 is fitted into a cavity 126 of the spigot so that the button is biased towards the retaining position 108. The spigot and the button are formed with a number of inter-engaging and complementary formations 128 which reduces the likelihood of the button rotating axially about the spigot. The cover plate 74 has a buttonhole 130 through which the button is accessible. The button has a stop formation 132 which acts against an underside 134 of the cover plate so that the button is prevented from being pushed through the buttonhole by the compression spring 120. The cover plate 74 has a central recess 136 through which the handle 34 extends when the handle is in the extended position 38. An inner end 138 has a plurality of stop formations 140 which allows the handle to be moved to the extended position 38 until one or more of the stop formations abut the cover plate. The second housing 22 is shown in greater detail in Figure 3. The assembly 12 includes, fitted to the second housing, a latch 144 which is movable between a locking position 146 which is shown in Figure 9 and an unlocking position 148 which is shown in Figure 3, a mechanism 150 which includes a latch drive plate which causes the latch to move between the locking and unlocking positions, and a stop member or pin 154 which is movable between a first position 156, which is shown in Figure 1 and at which the drive plate is prevented from moving the latch to the locking position, and a second position 158 which is shown in Figure 9 and at which the latch is movable by the drive plate to the locking position. The latch drive plate has a connecting member 160 which is engaged at a free end 162 with the drive chassis 24 in the following manner. A chamber 164 is formed inside the drive chassis at a suitable - 15 position and is defined at opposed ends by a wall member 166. The side walls 62 of the first housing is formed with suitable apertures 168 so that the free end 162 can extend through the first housing into the chamber. Thus, movement of the drive chassis between the upper and lower positions 26 and 28 is transferred via the connecting member 162 the latch drive plate. When the drive chassis is moved towards the lower position, the free end will engage with a wall member at an upper end of the chamber. Conversely, when the drive chassis is moved towards the upper position, the free end will engage with a wall member at a lower end of the chamber. The latch 144 has a cylindrical member 170 and a hook member 172 which extends radially from the cylindrical member so that the hook member rotates about a central axis 174 of the cylindrical member. Hook member has a hook portion 176 which extends transversely from the hook member so that the hook portion lies in the same plane as in which the cylindrical member lies. A spigot 178 extends from a side 180 of the cylindrical member and at a position which is off centre and on one side of the latch. The latch drive plate 152 is formed with a groove formation 182 into which the spigot 178 extends and is movable between an engaged position 184 at which the latch 24 is moved to the locking position 146, and a disengage position 186 at which the latch is moved to the unlocking position 148. The spigot 178 acts against a lower portion 188 of the groove formation when the latch drive plate is moved to the engaged position so that the spigot is rotated in a first direction 190 about the central axis 174 thereby causing the latch 24 to rotate about the central axis to the locking position 146. Conversely, the spigot acts against an upper portion 192 of the groove formation when the latch drive plate is moved to the disengage position so that the cylindrical member is rotated in a second, opposite direction 194 about the central axis thereby moving the latch to the unlocking position 148. The pin 154 is longitudinally movable inside a passage 196 which extends partly into the second housing 22 from an outer end 198 thereof. A biasing member or compression spring 200 is positioned between an inner end 202 of the pin and the blind end 204 of the passage. Thus, the pin is biased towards the first position 156. A collar 206 extends around the inner end 202 and which acts against part of the second housing 22 which defines a hole 208 in the outer end 198 from which the pin projects when in the first position. The latch drive plate 152 has a member 210 which extends from an upper end 212 thereof and which has a free end 214 which lies adjacent the collar 206 and against which the - 16 member pushes when the pin is in the first position so that the latch drive plate cannot be moved to the engaged position 184. Movement of the pin to the second position 158 displaces the collar transversely relatively to the member so that the free end can be moved past the pin between the collar and the opposed portion of the second housing. This allows the latch drive plate to be moved to the upper position so that the latch 144 is moved to the locking position 146. A cover plate 216 is engaged with one end of the second housing 22 thereby maintaining the components of the assembly which are fitted to the second housing substantially in position. Referring to Figure 9, the strike 14 has a cavity 218 into which the hook member 172 extends when the latch 144 is in the locking position 146. The cavity is profiled so that a ledge 220 is formed with which the hook portion 176 engages when the hook member extends into the cavity 218. The strike is secured to a frame member 222 of a frame to which the enclosure 18 is movably mounted with a plurality of fasteners 224. The strike has a projection 226 which extends from an operative side 228 of the strike and which can be registered with a locating recess 230 which is formed into the outer end 198 of the second housing 22. The cylindrical member 170 has a central passage 232 with which the latch 144 is pivotally mounted to the second housing 22 by inserting a spigot 234 into the central passage. The cylindrical member 170 therefore rotates about the spigot when the latch is moved between the unlocking position 148 and the locking position 146 at which the hook member 172 projects from the outer end 198 through a slot 236. The second housing 22 is fitted to the frame member 16 with a pair of fasteners 240 which extend through suitable apertures 242 which have been formed through a faceplate 244 which forms the outer end 198. A faceplate 246, see Figure 1, is clipped onto the cover plate 74 thereby rounding off the first housing 20. Figure I shows the latchset 10 in operation. Movement of the handle 34 between the retracted position 36 and the extended position 38, the latter of which is shown in Figure 1, results in the movement of the latch 144 between the locking position 146, which is shown in Figure 9, and the unlocking position 148. The latchset is fitted to the enclosure 18 by first securing the first housing 20 to the frame member 16, and thereafter the second housing 22 to -17 the frame member. The free end 162 of the connecting member 160 is inserted into the chamber 164 before the fasteners 240 are used to attach the second housing to the enclosure 18. Thus, longitudinal movement of the drive chassis 24 between the upper and lower positions 26 and 28, causes transverse movement of the connecting member relatively to the drive chassis. This causes the latch drive plate 152 to move between the engaged and disengage positions 184 and 186 which, in return through the engagement of the spigot 178 either with the lower portion 188 or the upper portion 192 of the latch drive plate, causes the latch 144 to move between the locking and unlocking position is 146 and 148. The operation of the handle 34 is shown in greater detail in Figures 4 to 6. In Figures 4 and 5 the handle 34 is in the retracted position 36 and in Figure 6 the handle is in the extended position 38. The handle is moved between the extended and retracted positions through the operation of the drive chassis 24. Movement of the drive chassis between the upper position 26, which is shown in Figures 4 and 5, and the lower position 28 which is shown in Figure 6, causes the first and second pairs of spaced apart spigots 40 and 42 to move along the pairs of spaced apart channels 44 and 46 of the drive chassis. Thus, movement of the drive chassis to the upper position 26 guides the handle towards the base portion 54 of the housing and as a result to the retracted position 36. Conversely, movement of the drive chassis towards the lower position causes the handle to move away from the base portion to the extended position 38. The movement of the handle away or towards the base portion, that is between the extended and retracted positions respectively, is achieved by the angle 52 with which the first and second spaced apart channels 44 and 46 extend across the side wall 48 of the drive chassis. As mentioned herein above, the drive chassis 24 is biased towards the lower position 28 through the extension spring 30. As the handle 34 is pushed into the first housing 20 by a user, not shown, the drive chassis 24 is moved against the biasing force of the extension spring 30 towards the upper position 26. This results in the first hook formation 114 of the button 32 engaging with the second hook formation 116 of the drive chassis. The engagement of the first and second hook formations to each other is facilitated by the yielding of the button through the compression spring 120 towards the releasing position 110. However once the second hook formation has moved over the first hook formation, the resilience of the compression spring moves the button towards the retaining position 108 so that the drive chassis is clipped onto the button. This configuration is shown in Figure 4.
- 18 In Figure 5 the button 32 has been pushed by a user, not shown, to the releasing position 110. This causes the first and second hook formations 114 and 116 to disengage from each other so that the drive chassis 24 is released from the button. This allows the drive chassis to be moved under the biasing force of the extension spring 30 from the upper position 26 to the lower position 28. This causes the handle 34 to move from the retracted position 36 to the extended position 38. The locating of the free end 162 of the connecting member 160 inside the chamber 164 of the drive chassis 24, results in movement of the drive chassis between the upper and lower positions 26 and 28 being transferred via the connecting member to the latch drive plate 152. However, movement of the latch drive plate to the engaged position 184 is only possible when the pin 154 has been moved to the second position 158 so that the free end 214 of the member 210 can move past the collar 206 of the pin. Thus, the handle 34 can only be moved by a user to the retracted position 36 when the pin has been moved to the second position. This is achieved by positioning the faceplate 244 adjacent the strike 14 so that the outer end 198 is nested with the operative side 228 of the strike so that the pin 154 is pushed to the second position 158 (see Figure 9). The lower end 96 of the drive chassis 24 rests on the shoulder 94 of the key cylinder 84 when the key cylinder is in the locked configuration 90 so that movement of the drive chassis to the lower position 28 is prevented when the button 32 is pressed. Movement of the key cylinder to the lock configuration 92 moves of the shoulder out of the path of the lower end so that the scene can move past the inner end 86 the key cylinder so that the drive chassis is moved to the lower position 28. Figures 7 and 8 show how the latchset 10 can be fitted to the frame member 16 so that the first and second housings 20 and 22 are positioned differently relatively to each other. Altering a length 250 of the connecting member 160 allows the first housing 20 to be fitted to the frame member further away from a leading end 252 of the enclosure 18 if required. For example, the leading end may extend some distance into a frame portion, to which the enclosure is movably mounted, before the leading end abuts the strike 14. This may require the first housing 20 to be moved a predetermined distance away from the leading end so that the first housing does not contact the frame portion before the second housing 22 is adjacent the strike. Alternatively, the frame portion may be profiled such that it is required for the second - 19 housing to be moved to one side of the leading end or the strike 14 is fitted to the frame portion at a position which requires the second housing to be fitted on one side of the leading end. The movement of the handle 34 to the extended position 38, and as a result the latch to the unlocking position 148, requires the key cylinder 84 to be in the unlock configuration 92 and the movement of the button 32 to the releasing position 110. Conversely, movement of the handle to the retracted position 36 by a user, and as a result the latch 144 to the locking position 146, is only possible if the pin 154 has been moved to the second position 158 through the positioning of the faceplate 244 adjacent the operative side 228 of the strike 14. The handle 34 is moved to the retracted position 36 by a user by pushing the handle into the first housing 20. However, the handle is moved to the extended position 38 automatically through the biasing force of the extension spring 30 if the key cylinder 84 is in the unlock configuration 92 and the button 32 is moved by the user to the releasing position 110. Referring to Figure 3, a variation 14A of the strike is shown. Referring also to Figure 9, like reference numerals are used to designate like components, unless where otherwise specified. The strike 14A has a first plate 256 and a second plate 258. Suitable fasteners 224A are used to secure the first and second plates to the frame member 222, not shown. The projection 226 is formed on the operative side 228 which is carried by the second plate 258. The cavity 218 is formed between the first and second plates with the lock portion 176 forming part of the second plate. The invention provides a latchset which requires a leading end of a door or window to which the latchset is fitted, to be positioned adjacent a frame portion to which the door or window is movably mounted before the leading end can be lock to the frame portion and before a handle of the latchset can be pushed into the door or window. The handle is automatically moved to a position at which the handle extends from the latchset through the operation of a button of the latchset. The latchset is furthermore lockable so that the movement of the handle to the extended position can be controlled through the operation of a lock. A latch of the latchset is prevented from being moved prematurely to a position at which the latch extends from the leading end thereby reducing the likelihood of the latch ramming into the frame portion to which the door or window is to be locked. The prevention of the latch from prematurely being moved to the extended position prevents the handle from being moved to the - 20 retracted position thereby reducing the likelihood of the latchset having an appearance that the door or window has been properly secured to the frame portion. The foregoing embodiments are illustrative only of the principles of the invention, and various modifications and changes will readily occur to those skilled in the art. The invention is capable of being practiced and carried out in various ways and in other embodiments. It is also to be understood that the terminology employed herein is for the purpose of description and should not be regarded as limiting. The term "comprise" and variants of the term such as "comprises" or "comprising" are used herein to denote the inclusion of a stated integer or stated integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required. Any reference to publications cited in this specification is not an admission that the disclosures constitute common general knowledge in Australia.