AU2004203029B2 - A lock for a displaceable wing - Google Patents

Description

FROM AlUSTRAlL LOCK PHONE NO. 61396865755 May. 29 2008 07:47PM P6 ci Title A lock for a displaceable wing.

Field of the Invention This invention relates to locks for sliding wings. A typical such wing comprises a patio door comprising a piece of glass supported by a narrow timber or aluminium frame, the frame being supported by rollers to enable the door to be moved in a direction parallel with the plane of the face of the door.

Prior Art Commonly, the interior portion of the lock for patio doors comprises an interior handle assembly supporting a hand operable lever, the interior assembly being mounted on the closing edge of the door and is supported on the face of the frame by two screws that pass through the door frame to engage in an exterior handle assembly on the exterior side of the door.

There are many types of such locks for patio doors (herein also referred to as sliding glass doors) having an arm with a hook shaped end that is pivoted into the engaging position while in other cases it is slid into engagement; in these types of locks, engagement is usually effected by operation of a lever or key One of objectives of the inventions within is to provide a lock where the cylinders are more accessible for ease of use.

COMS ID No: ARCS-192495 Received by IP Australia: Time 17:57 Date 2008-05-29 FROM AUSTRAlL LOCK PHONE NO. 61396865755 May. 29 2008 07:48PM P7 00 o 2 Summary of the Invention According to the invention there is a lock for a displaceable wing supported adjacent to San opening and including a catch plate supported by an element defining in part the opening and C a first lock portion including an interior portion mountable to the wing and including hand operable means, C> engaging means including at least one engaging arm engageable with the catch o plate in hooked engagement to restrain the wing from being displaced in an opening direction o and actuateable by the hmand operable means to release the catch plate, C, an exterior portion mountable to the wing and including an exterior key operable barrel within a lock cylinder operably con nected to the engaging means by a shaft to enable the 01 engaging means to be actuated by the barrel, the barrel being rearwardly disposed to provide improved accessibility for key operation as characterized by the pivotal axis of the barrel being rearwardly disposed of the pivotal axis of the shaft- In a second aspect of the invention, there is an interior lock cylinder supported within the interior portion and having an interior barrel operably connected to the engaging means enabling the barrel to actuate the engaging means.

In a third aspect of the invention, there is an angularly displaceable first cam operably connecting each barrel to the engaging means.

In a fourth aspect of the invention, each barrel is operably coupled with free movement to the first cam.

In a fifth aspect of the invention, the engaging means is controlled by the first cam wherein the first lock portion cannot be released from the catch plate by operation of the hand operable means when the first cam is disposed at a locking disposition.

In a sixth aspect of the invention, each barrel is operably coupled to the first cam by means including slide means.

In a seventh aspect of the invention, the engaging means includes a latching engaging arm defined in part by an engaged configuration in which it is engaged with the catch plate in hooked engagement to restrain the wing from being displaced in an opening direction, the latching engaging arm automatically engaging with the catch plate in hooked engagement as the wing is moved in a closing direction.

In an eighth aspect of the invention, the hand operable means includes a hand operable unlatching member and the latching engaging arm is operably connected to the unlatching member to enable the latching engaging arm to be released from the catch plate by unlatching member operation, and wherein each barrel is operably connected to the latching engaging arm COMS ID No: ARCS-192495 Received by IP Australia: Time 17:57 Date 2008-05-29 FROM AUSTRAL LUCK PHONE NO. 8 1396865755 May. 29 2008 07:48PM PS 00 by the angularly displaceable first cam to enable the latching engaging arm to be released from the catch plate by rotation if a barrla> in a ninth aspect of the invention, lock according to Claim 8, wherein the latching Cl engaging arm is spring biased towards the engageable position.

In a tenth aspect of the invention, the latching engaging arm has a hooked engagin g ON end.

O In an eleventh aspect of the invention, the engaging means includes an operable o engaging arm defined in part by an engaged configuration in which it is engaged with the catch Cl plate in hooked engagement to restrain the wing from being displaced in an opening direction.

O 10 In a tweith aspect of the invention, wherein the operable engaging amt has a hooked 0 engaging end.

In a thirteenth aspect of the invention, the hand operable means includes a hand operable locking member operable to actuate the operable engaging arm to and from the engaged position.

said operable engaging arm being operably connected to the barrel of eac h cylinder by the first camn to be displaceable to and from the engaged position by rotation of a barrel.

In a fourteenth aspect of the invention, the operable engaging arm is controlled by the angular disposition of the first cam wherein the operable engaging arm cannot be actuated from the e"gaged position by the locking member when the first cam is disposed at a locking disposition.

I a fifteenth aspcct of the invention, there is a lockling slide operably inconnecting the first cam and operable engaging arm, said first cam and locking slide being operably connected by an extension to the first cam that extends sideways to occupy a drive recess of the locking slide defined by drive shoulders, the locking slide being displaceable by rotation of the first cam to displace the operable engaging arm to and flom the engaged position.

In a sixteenth aspect of the invention, the locking slide is unable to be displaced by the locking member when the extension to the first cam is not between the drive shoulders.

In a seventeenth aspect of the invention, the first cam is at a locking disposition the point of contact on the locking slide by the extension to the firs t cam is defined by a normal vector that passes substantially through the axis of rotation of the first cam.

In an eighteenth aspect of the invention, the locking slide comprises a rectilinearly displaceable slide.

GUMS IDNo: ARCS-192495 Received by IP Australia: Time 17:57 Date 2008-05-29 FROM AUSTRAL LOCK PHONE NO. 6 1396865755 May. 29 2008 07:49PM P9 00 04 According to the invention there is a lock lock for a displaceable wing supported a> adjacent an opening, said lock including Cl a catch plate supported by an element defining part of the opening, an interior portion mountable to the wing and including a first cam and engaging 0> means engageable with the catch plate in hooked engagement to restrain the wing from being o displaced in an opening direction and hand operable means by which to actuate the engaging o means, Cl an exterior portion mountable to the wing and including an exterior look cylinder having a key operable barrel that is operably connected to the first cam by a shaft that has 0 passage through the wing, said barrel being defined by a pivotal axis that is rearwardly disposed of the pivotal axis-of the shaft, the engaging means being controlled by the angular disposition of the first camn wherein the engaging means cannot be released from the catch plate by the hand operable means when the first cam is disposed at a locking disposition.

In another aspect of die invention, the wing comprises a substantially conventional sliding glass door.

COMS 0 No: ARCS-192495 Received by IP Australia: Time 17:57 Date 2008-05-29 FROM AUSTRAL LOCK PHONE NO. :61396865755 Mlay. 29 2008 07:49PM1 00 Description of the Drawings Embodiments of the present invention will now be described by way of example only with reference 1.0 the accompanying drawings in which Figure 1 is a schematic side view of the lock when viewed from that interior side, Figure 2 is a schematic se~ctional view of the lock of Figure I when viewed from the ON opening edge of the wing, o Figure 3 is a schematic partial side view of an exterior portion, Figure 4 is a schematic partial plan view of the lock, and a partial cross-sectional view ci through the wing and the element defining part of the opening, Figure 5 is a schematic partial vertical cross-section through the disabling device, O Figue 6 is a partial schematic enlarged side view of the region adjacent to the first cam', Figure 7 is a partial side view of the rocker providing points of attachment for rods that operate remote locks, Figure 8 is a schematic partial side view of the lower end of the locking slide showing an impact absorbing connection to the second arm 22, Figure 9 is a schematic partial side view of the slides and cylinder where the barrel in the cylinder is disposed rearwardly of the first camn, Figure 10 is a schematic partial side view of slides and a cylinder of the lock of fig 1 where the barrel in the cylinder and the first cam have substantially( J pivotal ali.

hon 2 t44 1 Clt8'neA COMS ID No: ARCS-192495 Received by IP Australia: Time 17:57 Date 2008-05-29 6 Description of the Preferred Embodiments SIn a preferred embodiment, in summary, the interior portion of the lock comprises an interior portion including an interior casing and an interior handle portion said interior assembly mounted on the closing edge of the wing and supported on the face of the wing frame 50 by two screws that pass through two apertures in the interior casing and wing frame to engage in an exterior portion that includes a handle portion, the exterior portion being on the (-i Sexterior side of the wing. A third aperture located midway between the first two provides passage for a shaft.

(-i The interior assembly includes the box-like interior casing 1, that preferably comprises 10 a cavity within a handle assembly as shown in Figure 1.

(-i In preferred embodiments the interior portion includes a latchable first arm that projects forward to extend from an aperture in the front wall of the interior casing 1 to engage, (in usage), in a recess in a catch plate 24 mounted on the face of the element 50A defining part of the wing opening and these embodiments preferably include an interior hand operable unlatching member.

In other preferred embodiments the interior portion includes a second arm that projects from an aperture in the front wall of the casing 1 to engage, (in usage), in a recess in a catch plate 24 mounted on the face of the element defining part of the wing opening and these embodiments preferably include an interior hand operable locking member.

In other preferred embodiments again, the lock includes both the first and the second arm. All embodiments optionally include exterior and interior cylinders.

In embodiments employing the interior cylinder, there is supported within the interior casing a key operable interior cylinder 3, having an angularly displaceable barrel as is well known, and on the internal end of the barrel is an annular washer having an extension comprising the arm 4, by which the barrel operates the lock. Importantly the barrel is operably connected to a first cam 16 described below. This connection may take many forms; it may comprise for example, one or more pinned protrusions of the barrel locating within one or more recesses in the first cam 16. The preferred form employing an interspaced slide however, and as shown in the figures, enables a low casing height and facilitates easy insertionl and replacement of cylinders by simply removing a back or lid of the casing the cylinder is simply supported between such.

Accordingly, there is supported adjacent the internal end of the barrel end and coaxially with the barrel is a disc-like member 5 having radially protruding shoulders 6 and 7 between which the armed extension 4 of the washer locates with free movement to drive the disk-like member 5 the free movement enabling a barrel to be rotated in one direction to FROM :AUSTRAL LOCK PHONE NO. 61396865755 May. 29 2008 49PM P11 00 07 displace the disc-dike member 5, to operate the lock and then to be returned to the undispiaced position to enable key' removail. The disc-like member 5 has an armed extension 8 that locates within a substatially rectangular recess 9 within a first slide 10 Supported by the casing for (N sliding movement.

S Alternatively, not shown, the disc-like member 5 may have an arm having an orthogonal pinned protrusion wh ich locates within a slot within the side of the slide I10 and o alternatively, again not shown, the disc-like member 5 may have a geared profile which engages with a mating geared rack portion comprising an edge portion of the first slide.

Importantly, and as in the embodiment shown in the figures, the interior cylinder 3 (when included) and slide 10 are always operably coupled, (with some free movement) so that each O may impart displacement to the other within the range of normal movement; and in the preferred embodiment shown, the armed extension 8 is always within the recess 9 coupling thle two in slide/follower relationship. More specifically, the slide 10 is coupled with some free movement to the key operable angularly displaceable barrel of the cylinder.

In al] embodiments, there is supported by the interior easing an angularly displaceable cam 16 (also called herein a first cam 16) preferably having an axis of rotation parallel that of the cylinder barrel. This camn has an anned extension 17, similar to and preferably substantially the same as extension 8, which locates within a substantially rectangular recess 18 of the first slide 10, similar to recess 9. Importanitly the armed extension 17 is always coupled to the slide 10 so that each may impart movement to the other with in the range of normal movement; in the prefrred embodiment shown the extension 17 is always within the recess 18S. Within the underside of first camn 16 is a rectangular aperture 19 to accept and mate with a rod 20 (also called a spindle, a shaft] that passes through the wing to engage similarly in a cam within the exterior portion. In the embodiment shown, slide 10 can always be actuated to move by rotation of the rod 20 or by operation of the cylinder 3, because of the operable coupling described above between the cams 5 and 16 and the slide 10. Referring to the figures, it can be seen in fact that it is a operative end of the arm 17 disposed fromi the axis of rotation of the camn 16 that engages between upper and lower opposed shoulders that define the recess 18.

In the embodiments including an exterior cylinder, the exterior handle portion includes elements similar to those described above as shown in Fig. 3 and although better described below, a brief description is provided here to explain a important aspect of the lock. The rectangular rod 20 that passes through a third aperture in the wing locates in a mating rectangular recess in a second cam 36 that has an axis of rotation co-axial with that of first cam 16, said second cam 36 has an armed extension 37 which engages in a substantially rectangular recess 38 of a third slide 39 supported within the exterior casing 45 for sliding movement, said COMS IDNo: ARCS-192495 Received by IP Australia: Time 17:57 Date 2008-05-29 8 ,1 exterior casing comprising part of the exterior portion. Positioned above the cam is an exterior Scylinder 41 and an associated disc-like member 44 to which it is coupled with free movement by means described with reference to the interior cylinder, said disc-like member 44 having an armed extension 42 that engages in a substantially rectangular recess 43 in the slide 39. The cam 36 and the disc-like member 44 are operably coupled by the intermediate slide 39 such that movement of one causes the other to displace accordingly, in the same way that cams 16 and (-i Sare coupled by slide In embodiments employing both the exterior cylinder 3 and the exterior cylinder 41 each cylinder must be able to independently operate the lock irrespective of the configuration in which the lock is left after a previous operation. For example a lock when locked from the inside of the wing by key must be unlockable from the exterior by key and consequentially the mechanism interconnecting each cylinder to the other can be operated at all times by either cylinder.

The exact location of each cylinder is inconsequential to the lock operation and the cylinder barrels and first cam may lie in a vertical plane as shown in Fig 10. Preferably for ease of use, each cylinder is located well back from the front edge of the lock casing and rearward of the first cam as shown in Fig 9 where the recess 9 within first slide 10, (and preferably the recess 43 within second slide 39) is rearwardly disposed as shown in Fig 9 the respective casing being widened to accommodate this relocation of the cylinder. Alternatively the cylinders may be angled outwardly from the edge of the wing. The cylinders may also be located so the barrels are co-axial with the shaft 20, in which case the first and second slides would be omitted and the barrels would engage directly with the cams 16 and 36 with free movement to facilitate independent operation by each cylinder.

The preferred embodiments employ the first and second slides to facilitate the provision of preferred interior and exterior assemblies that have improved ergonomic aspects, that protrudes a minimum distance from the face of the wing, and enables cylinders to be located well back from the edge of the door to provide improved accessibility for key operation.

In embodiments including an interior locking member, the lock can be locked by either cylinder to become unable to be displaced from the locked configuration by the locking member.

In the embodiments including a second arm 22, there is preferably supported by the casing 1 a hand operable locking member 1 I coupled to a cam 12 having an armed extension 13, (and which is preferably similar to the armed extension and which locates within a substantially rectangular recess 14 of a third slide 21, (also referred to herein as a locking slide), to operably couple the third slide to the cam 12, supported within the interior casing 1 so that 9 the locking slide 21 may be caused to displace by operation of the locking member 11.

SImportantly the locking member is always operably coupled to the locking slide 21 so that one

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may be displaced to displace the other. The coupling may take many forms and may comprise, for example, a geared cam 12 mating with a geared rack portion of the slide 21, but in the preferred embodiment shown, armed extension 13 is always within recess 14.

As will be described below, when the locking slide 21 has been displaced to the upper (-i Slimit of displacement (the engageable position) and locked by a cylinder, it cannot be displaced Sfrom that configuration by the locking member 11.

The third slide, (locking slide) 21 supports the second arm 22, (also referred to herein 10 as a bolt) that is engageable behind a shoulder 23 of a catch plate 24. The third slide has a (-i substantially rectangular recess 25 defined by opposed upper and lower drive shoulders, said drive shoulders being engageable by the armed extension 17 of the first cam 16. Importantly the upper drive shoulder, (of embodiments including a second arm), is joined to an upwardly angled locking exit surface 26 and the lower drive shoulder, (of embodiments including a first arm), is joined to a downwardly angled unlatching exit shoulder 27 as shown in Fig 6, said exit surfaces enabling the operative end of the armed extension 17 to slide over the' surfaces 26 and 27 while not causing the third slide to displace substantially. The lock is configured such that when the third slide is between and displaced from its upper and lower extremities of displacement the first cam 16 and the third slide are operably coupled so that one may be displaced to displace the other but at the upper and at the lower extremity of third slide displacement, and corresponding to the operative end portion of the arm 17 being adjacent an exit surface 26 or 27 respectively, the first cam 16 is displaceable in coupled engagement with the first slide 10, (and consequently in coupled engagement with slide 39, the rod 20, and cylinder disc-like members 5 and 44) while the third slide is restained from displacement by the armed extension 17.

It can be seen from the figures that at the upper extremity of third slide displacement, the surfaces 26 is disposed substantially orthogonally to the pivotal axis of the first cam 16 while at the lower extremity of third slide displacement the surface 27 is disposed substantially orthogonally to the pivotal axis of the first cam 16. The upper extremity of the third slide displacement (called herein a locking position) corresponds to the second arm being in the engageable position which in practice would be behind shoulder 23 of the catch plate, while the lower extremity corresponds to an undisplaced third slide.

The configuration where the second arm is engaged with the catch plate and the operative end portion of the arm 17 is on the surface 26 and removed from the recess between the drive shoulders corresponds to an engaged and locked lock locked having the meaning of (Nio requiring unlocking by key before disengagement can be effected. This functionality derives Sfrom the third slide being unable to be displaced while the operative portion is on surface 26 since any attempted displacement of the third slide gives rise to a force on the first cam which is defined by a vector passing the pivotal axis of the first cam and that does not give rise to a moment on the first cam that might cause it to rotate.

In embodiments including the first arm, there is supported for pivotal movement co- Saxially with the cam 16, an annular member 28 having an armed extension 29 which supports ¢€3 the first arm 30, (also referred to herein as a latching beak), which is able to displace against (Ni biasing means, (to a disengaged position), to subsequently engage behind shoulder 80 of the strike plate in hooking engagement.

Cam 16 has a radially displaced shoulder 31, which is engageable with shoulder 32 of the extension 29 to drive the extension angularly to cause the first arm to displace from the engageable position, (which in use would be to disengage the strike plate). Importantly the shoulders are relatively angularly disposed such that the angular displacement of the first cam 16 which causes the first arm 30 to move from the engageable position substantially corresponds with displacement of the first cam armed extension 17 over the exits surface 27 of the third slide 21 which, as described above, remains restrained stationary, (to enable in usage), the first arm 30 to be disengaged from the strike plate without moving the second arm 22 from the undisplaced position.

In embodiments including a first arm 30, there is preferably positioned in the vicinity of the extension 29, a hand operable member comprising an unlatching member 70, that is engageable to the arm 29 such that it can be operated to cause the arm 29 to rotate to displace the first arm 30 out of engagement with the catch plate. As described above, the first arm 30 is operable from the interior by the unlatching member and by key. The unlatching lever may alternatively take the form of a lever supported coaxially with the cam 16 for angular movement, (not shown), which has an associated armed extension that locates adjacent to shoulder 32, said lever being operable to cause the extension to push upwards on the extension 32 to cause arm 29 to rotate to cause the first arm to disengage the strike plate.

The exact design is inconsequential to the functionality, but what it is important is that the arm 29 is supported with free movement to facilitate latching by the first arm 30 wherein the first arm 30 on striking the catch plate during closing of the door slides is displaced against the biasing action of spring 33 to subsequently be displaced to the engageable position and behind the shoulder 80. The arm 29 is biased towards the undisplaced, engageable position by a spring 33 and the first arm 30 has a ramped leading edge portion which on making engagement with shoulder 80 during latching engagement is caused to slide up the shoulder 80 and once the ramp 11 has moved past the shoulder the hook 30 is moved by the spring to engage behind the shoulder this latching of a hooked member is also well known.

The exterior portion comprises a handle and in embodiments including a first arm 30, it optionally includes an exterior unlatching member 46 for operating the first arm. The exterior portion is preferably retained by the screws which have passage through apertures 2 and which pass through the wing and engage in elongated bosses of the exterior casing 40. The rectangular (-i Srod 20 which passes through the third aperture in the wing, (preferably located midway between the other apertures as shown), locates in a mating rectangular recess in the second cam 36. The second cam 36 has an axis of rotation co-axial with that of first cam 16, said second cam 36 has 10 an armed extension 37 which engages in a substantially rectangular recess 38 of a third slide 39 (-i supported within the exterior casing 45 for sliding movement, said exterior casing comprising part of the exterior portion. Positioned above the cam is an exterior cylinder 41 and an associated disc-like member 44 to which it is coupled with free movement by means described with reference to the interior cylinder, said disc-like member 44 having an armed extension 42 that engages in a substantially rectangular recess 43 in the slide 39. The Cam 36 and the disclike member 44 are operably coupled by the intermediate slide 39 such that movement of one causes the other to displace accordingly, in the same way that cams 16 and 5 are coupled by slide The exterior displaceable unlatching lever 46 preferably comprises a radial extension 46A, disposed from the axis of rotation 46B of the said member and which is engageable within a peripheral recess 47 of second cam 36 when the operably connected armed extension 17 of the first cam 16 is adjacent the start of the surface 27, and as described previously, in this configuration the second arm 22 is undisplaced. The first slide 10 is the able to displace in an unlatching direction as the armed extension 17 slides over the surface 27 and so the second cam 36 and first cam 16 (which are connected by shaft 20) can be simultaneously displaced by operation of the exterior unlatching member to cause unlatching of the first arm 30. When the third slide is in a position removed from the undisplaced position, the corresponding position of the recess 47 is such that it is not within the locus of movement of the extension 46A and therefore the exterior unlatching lever is not able to operate the second cam to displace the first arm, and consequently when the lock is locked the recess 47 is withdrawn from an operative position.

Importantly it can be seen that part of the angular displacement of the sub-assembly comprising members 16, 20 and 36 (which are directly coupled without free movement) is utilizes for operating the first arm 30 while holding the second arm 22 in the undisplaced and non-engageable position, while another part of the angular displacement is utilized for 12

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displacing the second arm 22 between the engageable position and the undisplaced and non- Sengageable position while leaving the first arm 30 undisplaced, and a third part of the angular displacement is utilized for displacing the armed extension 17 to lock the lock by acting to restrain the second slide 21 and hence to restrain second arm 22 from being displaced from the engageable position.

As stated above, in the embodiment described herein, the key locking functionality is Scontrolled by the coupled members 5, 10, 16, 20, 36, 39 and 44 and this chain can be actuated Sby either cylinder 41 and 3 an important prerequisite for this is that there be sufficient free movement between the cam 5 and the barrel of cylinder 3 and between the cam 44 and barrel of cylinder 41 as described above. It should be noted that to enable locking by interior locking member, the first cam 16 has a neutral position corresponding to the extension 17 being adjacent the surface 27 while being within the recess between drive shoulders.

Preferably, the first slide 10 is releaseably retained in the locking position by a detent device, not shown but well known, comprising an outwardly biased ball supported within a recess within an edge of the slide and adjacent a mating recess within a interior casing wall within the loci of movement of the ball such that when the armed extension 17 is on face 26, first cam 16 is locking the third slide 21) the ball engages within both the recesses to require a significant force on the slide 21 to cause the ball to be dislodged from the recess in the casing. Preferably there is a second recess corresponding to the first cam 16 being in the neutral position where the armed extension 17 is between the drive shoulders and adjacent surface 27.

As with other locks and as is well known, the detent may also comprise a spring biased rocker arm which presses on the first cam 16 to restrain displacement and which urges the first cam 16 towards the neutral position when in the vicinity of the neutral position and which urges the first cam towards the locking position when in the vicinity of the locking position.

In embodiments where there is no key operable cylinder within the interior portion, the slide 10 and the chamfered or radiused surface 26 are optionally be omitted so that the second arm can always be displaced to the disengaged position by the interior by locking lever 11, i.e.

the exterior barrel cannot be operated to render the locking slide 21 immoveable by the locking lever 11 In other embodiments, the cylinder barrel is replaced by a hand operable thumb-turn.

In other embodiments the interior unlatching member 70 is omitted and in other embodiment again the external unlatching member 46 is omitted and in these latter embodiments the lock is operable by cylinder or as described immediately above, by a thumbturn lever.

In the locked configuration the fixing screws are preferably covered by plates 34 which 13 comprise extensions to the locking slide 2 land which during locking are moved vertically from Sbelow the said screw heads to be adjacent and over the fixing screws to render them inaccessible and similarly adjusting screw 35 which is accessible through an aperture within the casing in the unlocked position is moved to be remote from this aperture when locked, to be inaccessible.

One of the problems sometimes encountered by sliding wing locks is damage when a O locked lock is slammed against the catch plate 24. In a preferred embodiment this is addressed ¢€3 Sby having a device comprising a displaceable auxiliary bolt 51 outwardly biased by spring 54, (-i said auxiliary bolt having rearwardly a shoulder 52 of increased height as shown, such that when the catch plate is remote from the lock and now longer holds the auxiliary bolt depressed, the shoulder 52 is adjacent, to engage a flat portion 53 of the cam 12 to prevent rotation of this cam to thereby restrain the third slide from displacing from the disengaged, undisplaced position and as a consequence to ensure that the second arm 22 cannot be displaced to the engageable position. Inward depression of this auxiliary bolt through engagement with the catch plate causes the shoulder 52 to be moved out of the path of movement of cam 12 to enable the lock to be locked.

In another embodiment, the second arm 22 to locking slide 21 junction may include a partly compressed compression spring which is further compressible to absorb energy of wing closing. This preferably comprises a slideable plate 60 supported within a slot 61 of the locking slide 21 and urged towards the front edge by the partly compressed spring 62 said plate having a threaded fixing aperture in which the screw 35 locates to fasten the second arm to the plate 60. If the second arm 22 is impacted inwardly the slide plate 60 moves inwardly against increasing spring force to absorb some or all of the energy of impact to reduce the damage to the lock.

It should be noted that both points of attachment 35 for second arm 22 and 81 for first arm 30 accommodate adjustment by having slotted apertures in the first arm and second arm additionally the mating surfaces are knurled to prevent slipping between members and raised side walls on members 21 and 29 prevent sideways slipping of the associated arm.

In preferred embodiments the internal portion comprises a D shaped handle assembly as shown in Fig 1 having an unlatching lever 70 supported by the casing for angular rotation about a boss 66 and having an arm joined at the pivot point and angled so as to locate adjacent the extension 29 to be engageable with an anular boss 65 projecting from the side of arm 29.

Operation of the unlatching member causes the arm to rotate to engage the boss 65 to cause the first arm 30, arm 29 and member 28 sub-assembly to be rotated to displace the first arm 30 from the engageable position. As shown, the unlatching member is biased by spring 67 towards the 14 undisplaced, engageable position. The exterior portion also preferably comprises a similar a D shaped handle assembly as shown in Fig 3. Preferably the unlatching members are configured to pivot while unlatching in a direction corresponding substantially to the direction of wing opening so that in a simple natural motion the handle portion may be gripped and pulled in a simple natural motion.

Within the interior lever assembly shown there is optionally a disabling device 72 (Ni Scomprising one or more push buttons requiring depression before unlatching can occur by unlatching member operation such a device to make it difficult or impossible for children to (Ni unlatch the lock. In the device shown the device comprises a push button 73 supported within 10 the unlatching member 70 and which protrudes through an aperture 74 in the wall of the handle (Ni portion when the unlatching member 70 is in the undisplaced position. This button is outwardly biased by spring 75, has a conical head and as shown in Figure 8 that is operable by a finger to be moved to a position below the handle surface to enable the lever 70 to be rotated to operate the lock. The degree of difficult can be determined by the position and number of such buttons that must be simultaneously depressed while operating the unlatching member.

In lock optionally provides for remote locking by providing points of attachment for rods that connect to remote locks or vertically moving bolts. The rods 81 and82 connect to opposite ends of a rocker member 83 by pin joint and preferably each rod includes a rightangled return that locate in apertures in an end of the rocker member 83, said rocker member 83 is connected to the cam 12 by a shaft 84 as shown. When the locking slide displaces upwards the shaft 82 is driven upwardly while the shaft 81 is be driven downward. The rocker member as drawn would preferably be inserted within the wing frame and the shaft would pass into the frame to support and drive the rocker. Alternatively, not shown, the rocker is supported between interior casing I and the wing frame in a concave recess in the underside of the interior casing wall and is connected to the cam 12 by a shaft 84. The remote lock operating rods 81 and 82 have right-angled return that pass through vertical slots in the wing frame to locate within the apertures in the cam the vertical slots accommodating vertical displacement of the rightangled returns that pass through the wall of the frame. This later arrangement is quickly fitted by inserting the rods, placing the rocker over the rods returns and securing the rods to the rocker and then placing the shaft 84 into the rocker 83 as the interior assembly is fitted to the wing.

In the above description and claims, the terms first arm and second arm means separate arms that can be included one without the other or one with the other.

The invention provides many embodiments by the inclusion of different elements, e.g.

the first arm may be omitted while the second arm is included, one or both of the interior and exterior cylinders may be included, the locking member may be omitted or included, the child proofing feature may or may not be included.

SIn the above description the spatial prepositions, below above etc. are used for convenience of description only referring to a lock attached to a wing in the manner shown but they have no meaning beyond that.

Although the invention is described with reference to locks for sliding wings having, elements of the embodiments described are also applicable to other types of locks such as locks (-i Sfor hinged doors having sliding bolts.

¢€3 SThroughout this specification and claims which follow, unless the context requires (-i otherwise, the word "comprise" and variations such as "comprises" or "comprising", will be 10 understood to imply the inclusion of a stated integer or group of integers or steps but not the (-i exclusion of any other integer or group of integers and the positional prepositions such as up, down, rear which are used to assist in description of the preferred embodiments have in general no absolute significance.