NZ526403A - Releasable restrictor - Google Patents

Abstract

A releasable restrictor device for releasably restricting the extent of movement of a closure such as a window movably mounted with a frame. The releasable restrictor includes an arm (12) coupled to a slide mounted within a housing (19). The housing (19) has a mounting (10) to permit the housing to be mounted to the closure or frame. An engagement element (11) is provided and with which the arm (12) is releasably engageable. A release element, for example a key (39) is selectively engageable with the slide to cause the arm (12) to move, relative to the engagement element (11), to a release position. Following this any relative movement between the housing (19) and the engagement element (11) results in disengagement of the arm (12) from the engagement element (11).

Description

526403 PCT/NZO1/00281 TITLE OF THE INVENTION RELEASABLE RESTRICTOR BACKGROUND OF THE INVENTION This invention relates to a releasable restrictor.

For safety reasons or because of regulation there is often a requirement to be able to selectively restrict the degree of opening of a closure (door or window) movably mounted in a fixed frame. It is known to provide a hardware fitting, which can be mounted between the fixed frame and closure, to restrict the extent of opening movement of the closure relative to the frame.

An example of such a fitting is to be found in our New Zealand patent specification 188689. This fitting has been successfully marketed for many years under the trade mark SECURISTAY®. The SECURISTAY fitting provides an effective means of limiting the degree of opening of a window. The fitting can, however, be released so that the window can be opened to a wider extent for, say, cleaning purposes or to maximise ventilation.

In use, the SECURISTAY product is mounted to an external surface of the interior of the frame. Thus it is always visible and can accordingly distract from the aesthetic appeal of the window.

SUBSTITUTE SHEET (RULE 26) 2 In our New Zealand patent specification 330342 there is disclosed a releasable restrictor device which can be installed within a cavity between the frame and closure. The releasable restrictor device has an arm which is coupled to a mounting adapted for mounting with the frame or closure. An engagement member 5 adapted for mounting respectively to the closure or frame as the case may be, is engagable with the arm. The arm is movable relative to the frame and therefore when engaged with the engagement member limits the degree to which the closure can be opened. However the arm is capable of release from the engagement member so that the closure can be opened beyond the limited degree of opening to which the 10 closure is otherwise restricted by the arm.

The releasable restrictor device of NZ 330342 has met with success. However, one of the issues which has arisen with the device is that a penetration through the frame section is required to allow access of a release key used to release the arm when wider opening of the closure is required. This penetration potentially 15 reduces the air infiltration and water infiltration performance of the closure more particularly when the closure is a window.

SUMMARY OF THE INVENTION Broadly according to one aspect of the invention there is provided a releasable restrictor device for releasably restricting the extent of movement of a intellectual phuperty office of n.z. " 7 DEC 2004 .RECEIVED 3 closure movably mounted with a frame, the releasable restrictor including an arm coupled to a slide mounted with a housing, the housing including a mounting to permit the housing to be mounted to a closure or a frame, an engagement element with which the arm is releasably engagable, a release element in the form of a key 5 insertable in the housing, said key having an elongate shaft with an offset slide contact at its distal end whereby the key is selectively engagable via said distal end with the slide to cause the arm to move, relative to the engagement element, to a release position following which a relative movement between the housing and the engagement element results in disengagement of the arm and the engagement 10 element.

Preferably, the key further includes an engagement surface which engages with a surface of the housing to effect a lateral translation of the direction on which the shaft is inserted to thereby bring the slide contact into engagement with the slide.

Preferably the key is insertable through a slot in a bezel assembly. The bezel 15 assembly includes a pair of oppositely disposed seals between which the key is insertable.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of the releasable restrictor device according to one form of the present invention; "7 "EC 2004 Receive o Figure 2 is an exploded view of the components of the device shown in Figure 1; Figure 3 is a perspective view of the release slide of another arrangement (not in accordance with the invention); Figure 4 is a button which in use is associated with the release slide of Figure 3; Figure 5 is a perspective view of the restrictor body and restrictor slide in combination with the button illustrating a "latched" configuration; Figure 6 is a perspective view of the restrictor slide and button in the latched configuration of Figure 5; Figure 7 is an elevation view of the arrangement shown in Figure 6; Figure 8 is a view similar to Figure 5 but in the unlatched configuration; PCT/NZO1/00281 Figure 9 is a view similar to Figure 6 but with the restrictor slide and button in the unlatched conf igurat ion, Figure 10 is a plan view of the arrangement shown in Figure 9, Figure 11 is a side elevation view of the arrangement shown in Figures 9 and 10, Figure 12 is an exploded perspective view of a bezel assembly for use with, the releasable restrictor as shown in Figures 1 and 2, Figure 13 is a reversed perspective view of the arrangement shown in Figure 12, Figure 14 is a view similar to Figure 13, but showing the bezel assembly partially assembled, Figure 15 is a perspective view of the release key for the restrictor as shown in Figures 1 and 2, Figure 16 is a plan view of the key Figure 15, Figure 17 is a side elevation of the key of Figures 15 and 16, Figure 18 is an underside view of the body position of the restrictor, SUBSTITUTE SHEET (RULE 26) PCT/NZO1/00281 6 Figures 19 and 20 are a further embodiment of the sash bracket assembly, and Figure 21 is an exploded perspective view of a further form of the housing and mounting.

In a preferred form of the invention the device is arranged so that the restrictor base 10 is attachable to the frame with which the closure (e.g. window) is movably mounted. The base 10 has a plurality of openings 13 whereby it can be fixed, using mechanical fasteners, to the window frame. As shown in Figure 1, the fastener openings 13 can be a single opening toward each end of the base 10. An alternative is to have a single round opening at one end of the base and an elongate opening towards the other end.

A bracket assembly 11 is mountable to the closure. As the present invention is particularly suited for installation within a cavity between the sash and the frame of a typical aluminium or uPVC window the following description will relate to the device when used in conjunction with a window sash mounted with a window frame. Accordingly, bracket assembly 11 will commonly be referred to as a sash bracket assembly 11.

The sash bracket assembly 11 is according to one embodiment assembled from two pressed metal pieces namely a sash mount 11a and a sash bracket lib that are fitted into a plastic sash insert lie. Fasteners engaged through aligned openings lid hold all three pieces together with a sash stud or rivet SUBSTITUTE SHEET (RULE 26) PCT/NZfl 1/00281 7 24 through aligned openings lie becoming a pin onto which, the restrict arm 12 latches (as hereinafter will be described).

The sash bracket assembly 11 has two aligned elongated holes 14. Through each of these fasteners can engage to mount the assembly 11 to a sash. The elongation of the holes permits adjustment of the sash bracket assembly on the sash when fitted to the sash. Aligned holes 14a in the centre of the assembly 11 are used to fix the sash bracket assembly 11 in its final adjusted position.

As a safety feature the head of a fixing screw or rivet that passes through aperatures 14a is covered by the restrict arm 12 when the sash is in the open position. This means that the screw or rivet in holes 14a cannot be removed when the restrictor is in the latched position.

Restrict arm 12 extends in use between the base 10/housing 19 and the sash bracket assembly 11. Arm 12 is mounted via a pivot 15 which is slidingly engaged in a slot 16 of a frame plate 17. Plate 17 locates within a similarly shaped area 18 in a restrictor body 19. Area 18 is provided with a cut-away area 19a to provide a clearance for movement of the head 15a of the rivet 15.

The shank of the rivet 15 extends through the slot 16 in plate 17. A waisted or reduced diameter end 15b of the shank engages through an opening 36 in release slide 33 and into opening 20 in restrict arm 12. This waisted or reduced diameter end 15b is swaged over to thereby couple the arm 12 to the rivet 15, The shank of the rivet 15 can thus slide in slot 16.

SUBSTITUTE SHEET (RULE 26) PCT/NZO1/00281 8 Plate 17 includes openings 22 {at or toward each end) which align with openings 23 in recessed area 18 to enable the passage of mechanical fasteners (not shown) for not only mounting the plate 17 within the recessed 18 but also for further fixed attachment of the base 10 and restrictor body 19 to the window frame.

An open ended longitudinally extending slot 25 is provided toward the distal end of restrict arm 12. The arm 12 can be engaged with sash bracket assembly 11 by locating slot 25 on rivet or stud 24. The arm 12 can thus pivot about the axis of rivet or stud 24. The open ended slot 25 is provided with a divergent mouth 26 for the purpose which will hereinafter be identified.

The distal end of restrict arm 12 is shaped such that when the restrictor is in the latched condition and the sash opened, the shaped end 12b of restrict arm 12 is located in a similarly shaped area llf in the sash bracket 11. This retains the slot 25 in engagement with the rivet or stud 24 in sash bracket 11 thereby stopping arm 11 from being unlatached from rivet or stud 24 when the sash is in the open position.

When the sash is moved to the closed position the shaped end 12b at the distal end of restrict arm 12 rotates to a position that is clear of the shaped area llf in sash bracket 11. The restrict arm 12 is thus freed to move longitudinally upward relative to the sash bracket 11 and more particularly rivet or stud 24.

SUBSTITUTE SHEET (RULE 26) Extending inwardly from the other side edge of restrict arm 12 is a shallow slot 27 or rebate. The slot 27 is located between opening 20 and slot 25 but nearer to the latter.

As can be seen in Figure 1, a protrusion 28 at or near the end of a restrictor body 19 is engagable within slot 27. Figure 1 also shows that the restrictor body 19 locates on the base 10.

Extending along one of the long sides of restrictor base 10 is a track 29 which in cross-section is curved. The track 29 fits into a shaped elongate recess along the corresponding long side of restrictor body 19. When the restrictor body 19 is in place on restrictor base 10 an elongate cavity 29b in body 19 fits with part of track 29 to form a cavity in which an end of spring 31 is located.

The spring 31 engages at one end with the end wall 34 of cavity 29b and at its other end pushes against a lug 32 of the release slide 33. The lug 32 slidingly engages in a cavity formed by track 29 and a curved track section 29a (see Figure 18). The release slide 33 is thus biassed to a position where it essentially locates beneath the cover portion 35 of the restrictor body 19.

The restrictor body 19 has a cut-out portion 37 in the long sidewall thereof this cut out substantially corresponding in position with the cut away area 19a. This provides a clearance for the join between cylindrical lug 32 and the body of release intellectual property office of n.z. -7 DEC 2004 RECEIVED 9a slide 33.

It will be appreciated that in use the body 19 is located so that it is vertically orientated on the window frame i.e. intellectual property office of n.z. - 7 DEC 2004 RECEIVED projection 28 will be uppermost and cover 35 lowermost. The spring 31 thus forces the release slide 33 down (and consequently also the restrict arm 12) toward the cover 35 end of the restrictor body 19. In the normally latched position, therefore, the cut-out or slot 25 in the distal end of the restrict arm 12 is held in engagement with the rivet/stud 24 in the sash bracket assembly 11.

To unlatch the restrictor a key 39 is inserted through a slotted guide (not shown) in an aperture 38 (see Figure 18) in the body 19. Key 39 has a head 40 and a shaft 41. The shaft 41 is of flat elongate form as can be seen in Figures 15-17. In the preferred form a bulbous portion 42 at the distal end of shaft 41 is offset to one side of the longitudinal axis of shaft 41. An inclined edge 43 extends from the bulbous portion 42 to a side edge 44 of shaft 41. As can be seen the shaft 41 is of thinner cross-section at edge 44 than at opposite edge 45.

The inclined edge 43 of the key 39 runs against a correspondingly sloped face 45 within the restrictor body when the key 39 is inserted. When the key is pushed into the restrictor body 19 the rounded or bulbous portion 42, opposite the inclined edge 43 locates behind an up-stand 47 inside the restrictor body 19. This limits the extent by which the key 39 can be inserted. The bulbous portion 42 engages against an edge of the land 48 on the release slide 33 as it is inserted into the body 19. This, therefore, creates the pushing effect on release slide 33 so that the release slide 33 moves against the bias of the spring 31.

SUBSTITUTE SHEET (RULE 26) PCT/NZO1/00281 11 The restrict arm 12 is thus moved longitudinally upward relative to the rivet/sash stud 24. This aligns the rivet/stud 24 with the open mouth 26 of slot 25, thereby allowing the sash bracket assembly 11 and the restrict arm 12 to disengage when the sash is opened.

Also as the restrict arm 12 is moved longitudinally the notch or slot 27 cut-out in the body of the restrict arm 12 locks under the projection 28 at the top of the restrictor body 19. The bottom face 27a bears against the bottom 28a of the projection 28 and stops the restrict arm 12 from being pulled outwards when the sash is opened.

In the unlatched condition when the key 39 is removed the spring 31 pushes the release slide 33 and restrict arm 12 down so that the top face 27b on the notch 27 in the restrict arm 12 bears against the top 28b of the projection 28. This hold the restrict arm 12 in place ready to be re-latched to the sash bracket assembly 11 when the window sash is moved to the closed position.

If the restrict arm 12 is dislodged from the projection 28 when the sash is fully opened the spring 31 forces the release slide 33 down causing the bottom edge 12a of the restrict arm 12 to come in contact with the restrictor body 19. The relative profile of the engaging surfaces thereby causes the restrict arm 12 to be rotated back into a position where the sash bracket assembly 11 can automatically re-latch when the window sash is moved to the closed position.

The spring 31 also forces the key 39 out of the restrictor body 19. This means that the key 39 cannot be left in place.

SUBSTITUTE SHEET (RULE 26) 12 Consequently the key 39 must always be deliberately inserted in order for the restrictor to be released.

The offset operating end of shaft 41 of key 39 ensures that it is difficult to operate the release slide 33 with something other than the key e.g. a knife blade or screwdriver. Therefore, a good degree of security is achieved by having the specially shaped key which when inserted in a longitudinal direction (relative to the shaft 41) results in a transverse disposition of the shaft 41. This results in the bulbous portion 42 appling a pushing force substantially transverse to the longitudinal direction of insertion of the key 3 9.

The shaft of the key 39 could be simply inserted through a suitably sized elongate opening in the window frame member. It will be appreciated by those skilled in the art that the length of the elongate slot will be greater than the width of the shaft 41 because sufficient clearance needs to be provided for the transverse translation of the key arising from the inclined edge 43 engaging with the similarly inclined surface 45 within the restrictor body 19.

According to the present invention, however, a bezel assembly 50 is located over the penetration in the frame member. The bezel assembly is more particularly shown in Figures 12-14. It comprises a bezel mount 51, a bezel body 52 and two sealing elements 53.

The bezel mount 51 is formed by a plate 54 in which an elongate opening 55 is located. The elongate opening 54 in the frame, therefore, has a wide section 55a and a narrower SUBSTITUTE SHEET (RULE 26) 13 section 55b. The plate 54 further includes a pair of openings 56 each with a surrounding turret 57. A mechanical fastener can thus engage through each opening 56 to mount the plate 54 to the window frame. The heads of the fasteners are located within turret 57.

As can be seen from Figure 13 the underside of the plate 54 incorporates a projecting portion 58 in which the opening 55 is located. This projection 58 engages within a similarly-shaped opening formed in the frame member of the window frame.

The bezel body 52 engages over the bezel mount 51. Within the hollow interior of the body 52 there is provided a pair of spaced apart bores 59. These push fit over the turrets 57 to mount the body 52 to the bezel mount 51. Adjacent each of these bores 59 are a pair of divergent slot's 60 which provide mounting points for the sealing elements 53.

Each sealing element 53 is manufactured from a pliable plastic material. The sealing element 53 has a pair of inclined surfaces 61 which push fit into the opposing slots 60. Thus the sealing elements 53 are insertible into the bezel body 52 so that the two inclined sealing surfaces 63 of the respective sealing elements 53 touch at or toward their distal ends and are inclined towards the outside of the window.

Even though the two sealing surfaces 63 touch they are flexible enough that the release key 39 can be pushed through them to engage through slot 55 and into engagement with the releasable restrictor. Because the key 39 is only used when SUBSTITUTE SHEET (RULE 26) PCT/NZO1/00281 14 releasing the restrict arm 12 the sealing qualities when the key is inserted into the bezel assembly 50 is basically irrelevant. However, when the key is not inserted and the window is shut any positive pressure generated in the window cavity causes the sealing members 53 to deform in such a way that they close together and prevent the flow of air and/or moisture into the house interior. The bezel assembly 50 therefore provides a means of sealing the penetration in the frame member in a practical and aesthetic manner.

To further describe the invention, reference will be made to the restrictor in use with a window construction.

The base 10 and restrictor body 19 combination and the sash bracket assembly 11 are mounted as previously described to the frame and sash respectively of the window. As shown in Figure 1, the restrict arm 12 is coupled at its distal end via slot 25 to the rivet or stud 24 of the sash bracket assembly 11. Figure 1 shows the restrictor device when the window is in the fully closed position.

As the window commences its opening movement that protrusion 28 releases from slot 27. As the window continues its opening movement the rivet 15 slides up along slot 16 until it reaches the opposite end of slot 16. This prevents any further movement of the arm and hence any further movement of the window sash. The extent by which the window sash can be opened is thus limited by the restricted movement of rivet 15 in slot 16.

If, however, opening of the window to a greater extent is required (say, for cleaning or unrestricted ventilation) the SUBSTITUTE SHEET (RULE 26) PCT/NZO1/00281 user inserts release key 39 when the window sash is in the closed position. The bulbous portion 42 on the end of the shaft 41 of the key is offset from the longitudinal axis of the shaft 41. Consequently, insertion of key 39 translates into a longitudinal sliding movement of release slide 33.

The sliding movement of the release slide 33 causes restrict arm 12 to also move longitudinally Relative movement between protrusion 2 8 in slot 27 results from the sliding movement of arm 12. The resultant relative movement between the rivet or stud 24 and arm 12 causes the rivet or stud 24 to take up a position adjacent mouth 26 of slot 25. Upon this movement having taken place the window sash can be pushed open which causes the sash bracket assembly 11 to move away from the restrict arm 12, the arm being held against movement with the sash bracket assembly 11 by the protrusion 28 in slot 27. The sash can thus be moved to a fully open position or indeed any position beyond the open position to which the window sash is normally restricted by restrict arm 12.

When the key 39 is withdrawn spring 31 biases the release slide 33 back to its normal rest position.

When the window is closed the rivet or stud 24= enters the mouth 26 and moves into the confines of slot 25. The arm 12 is therefore automatically re-engaged with the sash bracket assembly 11 upon the window closing. Consequently, when the window is next opened the window sash will only be able to move to its restricted position unless, once again, the key 39 is inserted.

SUBSTITUTE SHEET (RULE 26) 16 The present invention thus provides a releasable restrictor device which is of compact construction enabling it to be installed within the cavity between the sash and frame of a typical window construction such as an aluminium or uPVC window. Therefore, the restrictor device is not readily apparent except for principally the opening and bezel assembly 50 for key 39.

The releasable restrictor according to the invention is open to modification as will be appreciated by those skilled in the art. One such modification is illustrated in Figures 3-11.

In Figure 3 there is shown a modified form of the release slide 33. The portion of the release slide 33 opposite to that to which the restrict arm is pivotally coupled includes a transverse slot 70 into which a mouth 71 opens from the end 72 of the release slide 33. The transverse slot 70 includes at each end a portion 73 which inclines towards the land 34. The reason for the configuration of end 72 will hereinafter become apparent.

In this form of the invention a release key 39 is not required. In its place is provided a button 74 which is used to cause the restrict arm 12 to be released from the sash bracket assembly 11.

The button 74 engages in an opening 75 in the cover portion 35 in the restrictor body 19. The release button 74 can adopt two different position, one being the latched position as shown in Figure 5 and the other a depressed and hence unlatched position as shown in Figure 8. As can be seen from SUBSTITUTE SHEET (RULE 26) 17 Figure 8 the button 74 is in addition to being depressed in opening 75 is also slightly rotated in a clockwise direction.

Button 74 has two lugs 76 one on each side with locate within two recesses (not shown) in the restrictor body 19. A small spring (also not shown) which is inside the bottom of the button 74 biases the button to the wout" position of Figure 5.

When the button 74 is in the "out" position the release slide 33 can slide beneath the button 74 as shown in Figures 6 and 7.

When the button is moved to the unlatched position (this movement only being able to be carried out when the window is in the open position) the button 74 is pushed inward and turned through a small angle. The two lugs 76 on the sides of the button 74 now prevent the button from moving under the influence of the spring to the out or latched position.

Consequently when the restrictor is closed the release slide 33 comes into contact with a flat surface or shoulder 77 on the bottom of the button (see Figure 11) . This prevents the release slide 33 from travelling down and thereby causes the restrict arm 12 to be lifted clear of the rivet/stud 24 of the sash bracket assembly 11 during the final closing of the window.

During the next opening of the window the window sash will be able to move to a wider extensive opening for say cleaning or greater ventilation. The button 74 can then be manipulated back to the out or latched position so that when the window SUBSTITUTE SHEET (RULE 26) 18 is next closed the restrict arm 12 re-engages with the sash bracket assembly 11. Consequently when the window is next opened it will only open to the restricted degree of opening.

The slotted feature 70, 71, 73, described above, which forms the end part 72 of the release slide 33 which comes into engagement with the button 74 allows for a small amount of movement of both the slide 33 and restrict arm 12 so that the arm 12 can clip on to the holdback feature (i.e. protrusion 28) at the top of the restrictor body 19.

Thus with this modified form of the invention no penetration needs to be made in the surface of the window frame which is open to the interior of the building for insertion of a release key. Not only does this overcome the problems which can be caused by air/moisture accessing the interior of the building but also means that the aesthetic appearance of the frame is not altered by the need for an opening for the release key or the bezel assembly 50 as previously described.

According to a further form of the invention Figures 19 and 20 show a modified form of the sash bracket assembly. In this form the two fasteners to couple the bracket components are not used.

As shown the press steel parts 11a and lib are assembled together by legs or tabs llg on the part 11 fitting through slots llh in the sash mount 11a and being formed over (not shown) to lock the two parts together and encapsulating the sash insert 11c.

SUBSTITUTE SHEET (RULE 26) 19 There are also two upstands/pips/llj on the sash insert lib that fit into two holes in the sash bracket lib to locate the sash insert lib.

In Figure 21 a means of coupling the mounting base 10 with housing 19 is shown. The base 10 has clips/tabs 80 that fit into the housing 19 to hold the two parts together. These clips 80 engage with shoulders or lands 81. There is also an upstand 82 that fits into a corresponding hole (not shown) in part 83 of housing 19 which forms protrusion 28. The upstand 82 fitting into the hole prevents the base 10 and housing 19 moving laterally which would otherwise allow the clips 80 to become disengaged.

The fitting of the fixing screws acts as an additional means of holding the two parts together once installed.

A user, therefore, has in a very simple manner the option of selecting opening of the window to its restricted extent of opening or to a far greater degree of opening. However, in the event that the greater degree of opening is selected the window will, upon closing, automatically result in the restrictor device re-latching thereby preventing opening beyond the restricted extent of opening unless the key is inserted or the release button manipulated.

SUBSTITUTE SHEET (RULE 26)

Claims (1)

20 WHAT WF.n ATM TQ

1/ A releasable restrictor device for releasably restricting the extent of movement of a closure movably mounted with a frame, the releasable restrictor 5 including an arm coupled to a slide mounted with a housing, the housing including a mounting to permit the housing to be mounted to a closure or a frame, an engagement element with which the arm is releasably engagable, a release element in the form of a key insertable in the housing, said key having an elongate shaft with an offset slide contact at its distal end whereby the key is selectively engagable via 10 said distal end with the slide to cause the arm to move, relative to the engagement element, to a release position following which a relative movement between the housing and the engagement element results in disengagement of the arm and the engagement element. 15 2. A releasable restrictor as claimed in Claim 1 wherein the key further includes an engagement surface which is engagable with a housing surface to effect a lateral translation of the shaft when it is inserted into the housing to thereby cause contact between the slide contact and the slide. intellectual property office of n.z. -7 DEC 2004 RECEIVED 21 3. A releasable restrictor as claimed in Claim 1 or 2 wherein the key is insertable through a slot in a bezel assembly. 4. A releasable restrictor as claimed in Claim 3 wherein the bezel assembly includes a pair of oppositely disposed seals between which the key is insertable. 5. A releasable restrictor as claimed in Claim 4 wherein the seals are formed as sealing members which are located in a bezel housing, said bezel housing being mountable with a bezel mounting base. 6. A releasable restrictor as claimed in any one of the preceding claims wherein the arm is pivotally coupled to the slide by a fastener, said fastener being slidingly coupled to a frame plate mounted with the mounting. 7. A releasable restrictor as claimed in Claim 6 wherein the fastener is slidingly retained in a slot in the frame plate. intellectual property office of n.z. - 7 DEC 2004 RECEIVED 22 8. A releasable restrictor as claimed in any one of the preceding claims further including an arm retention member engagable with the arm when said arm is moved to the release position. 9. A releasable restrictor as claimed in Claim 8 wherein the retention member is a protrusion of the housing which engages within a slot in the arm. 10. A releasable restrictor as claimed in any one of the preceding claims wherein the arm includes at a distal end an open ended slot engagable with a pin of the engagement element. 11. A releasable restrictor as claimed in Claim 10 wherein the slot includes a divergent mouth opening from the slot to an edge of the arm. 12. A releasable restrictor as claimed in any one of the preceding claims further including a biassing element within said housing to apply a biassing force to the slide. intellectual property office of n.z. - 7 DEC 2004 RECEIVED 23 13. A releasable restrictor as claimed in Claim 1 substantially as herein described with reference to Figures 1,2, 12 to 17 and 18 to 21. ASSA ABLOY FINANCIAL SERVICES AB By its Attorneys DON HOPKINS & ASSOCIATES PER: