WO2005108719A1

WO2005108719A1 - Security mechanism

Info

Publication number: WO2005108719A1
Application number: PCT/GB2005/001690
Authority: WO
Inventors: Geoffrey Clark
Original assignee: Easylock Limited
Priority date: 2004-05-08
Filing date: 2005-05-03
Publication date: 2005-11-17
Also published as: GB0410316D0

Abstract

A security device for a handle, a handle assembly incorporating the same, and a method of fitment of the same are described. The device consists of a modified spindle for the handle which has at least one first portion having a cross-sectional shape and extent such as to mechanically engage with a handle operating mechanism such that rotation of the spindle acts to effect to and fro motion of the catch, and at least one second portion laterally spaced from the said first portion being of reduced cross sectional extent such that the spindle with the second portion in suitable position does not mechanically engage and does not act upon the catch.

Description

SECURITY MECHANISM

The invention relates to a mechanism to disable and prevent unauthorised use of a handle on an openable closure such as a door, window or the like, for security and/ or privacy. The invention also relates to a handle arrangement incorporating such a security/ privacy mechanism. The invention in particular relates to a security mechanism provided, for example as an after market fitment, as a simple secondary level security or privacy device to handles of closures whether or not otherwise fitted with more sophisticated primary devices such as conventional locks.

Openable closures such as doors, windows or the like are conventionally provided with releasable closure mechanisms consisting of a closure bolt, latch or catch piece, typically within the door or window frame, and adapted to be retractably inserted into a receiving aperture in a door jamb or window surround by action of a rotating spindle generally passing through and perpendicular to the door or window and caused to rotate by operation of a suitable handle.

It is sometimes necessary or desirable for reasons of security or privacy to secure such closures against opening by unauthorised persons. This has particularly been the case in relation to external domestic doors. Traditionally, this has been done by the provision of bolts and locks fitted to the closure in addition to the handle. These have often operated on similar principles, for example involving sliding portions securable in recesses in the door jamb or window frame to prevent opening of the door, but are set up to be accessible only from one side thereof (eg to be operated from the inside only) and/or to be operated by a key or other security device. An increased need for security, particularly in domestic situations, has become progressively more important in recent years. To provide such additional security, two developments in particular have been notable. First, mechanisms have been developed which incorporate a lock into the handle of external doors to selectively lock the handle and prevent its unauthorised use. Second, attention has been increasingly paid to providing means to lock internal doors or door handles and to provide locks on window handles. It can also be desirable to provide simple internal locks for other reasons, for example for privacy.

In each of these cases, the same general problem arises, in that it is necessary to develop a device which is effective in preventing unauthorised or unwanted operation of the handle of the door, window or other closure. However, there is a general desire that such devices should be relatively simple to operate. Generally speaking, devices whose operation proves too complex are unlikely to be used regularly, particularly in a domestic situation.

A number of prior art devices have been proposed to afford additional security/ privacy by selectively preventing use of door and window handles. These operate along several general principles. First, devices are proposed which are designed to engage the door or window bolt or latch in a locked closed position. Second, mechanisms have been proposed which selectively disengage the spindle (and hence the handle) from the bolt or latch. Third, mechanisms have been proposed which lock the spindle itself, preventing its rotation.

None of these approaches are entirely satisfactory. They are all likely to require specifically designed mechanisms of spindle and/or latch/bolt, which is likely to increase complexity and therefore result in more opportunities for malfunction, difficulties in fitment and increased costs. In particular, there is obvious danger if a lock should fail in locked position. Moreover, the need for special components and/or for specific grooves or apertures or the like to be cut in existing components limits the effectiveness of such devices for after- market fitment to existing door and window handles.

It is an object of the present invention to provide a security/ privacy mechanism for a handle on an openable closure such as a door or window which serves to prevent unauthorised or undesired use of the handle and which mitigates some or all of the above disadvantages.

It is a particular preferred object of the present invention to provide a security/ privacy mechanism adapted for simple action to secure such a handle, in particular as a secondary security device either as an additional mechanism on a closure provided with more conventional security devices, or as a security mechanism on a closure conventionally not provided with any such security devices.

It is a particular preferred object of the present invention to provide a security/ privacy mechanism suitable as a secondary security device in a domestic situation, for example for internal doors and windows, especially those not otherwise conventionally fitted with more sophisticated conventional locks.

It is a particular preferred object of the invention to provide a security mechanism offering potential for after-market fitment as a modification to existing handles.

Thus, in accordance with the present invention in a first aspect there is provided a security mechanism for a handle of a closure, comprising a spindle suitable for fitment to the handle of the closure. The handle assembly to which the spindle is to be fitted comprises a handle assembly for fitment to an openable closure such as a door, window or the like, which handle assembly comprises a catch adapted to be received in a suitable recessed socket in a frame of the closure to retain the closure in a closed position, operably linked via a mechanical coupling to a rotatable spindle in such manner that rotation of the spindle draws the catch from the socket to free the closure and allow it to be opened.

In particular, the spindle is adapted to be received in a recess in the mechanical coupling to effect mechanical engagement therewith in use. For example in such an arrangement the catch is adapted for mounting for linear movement parallel to the closure surface between a retracted position and an extended position in which it engages a socket in a frame surrounding the said closure to effect closure thereof, a sliding member mechanically coupled to the catch and adapted to slide to and fro therewith, a spindle extending generally perpendicularly to the sliding member, and received through a recess therein such that rotation of the spindle causes movement of the sliding portion and retraction of the catch, and a handle means mechanically coupled to the spindle to allow a user to effect such rotation. To this extent, the arrangement will be familiar.

The spindle in accordance with the invention is characterised in that it has at least one first portion having a cross-sectional shape and extent such as to mechanically engage with the mechanical coupling, for example with at least a portion of the said recess, and in particular to be received snugly within the said recess, such that rotation of the spindle acts upon the catch, for example via the sliding portion, in use to effect to and fro motion thereof, and at least one second portion laterally spaced from the said first portion being of reduced cross sectional extent such that with the second portion in suitable position the spindle does not mechanically engage with the mechanical coupling, and for example does not engage with the said recess and in particular fits loosely within the said recess in use and does not act upon the sliding portion.

In use, the spindle is slid, and is preferably specifically adapted to be slid, between a first position whereat a said first portion of the spindle is engaged, for example within the recess, and rotation of the spindle serves to cause lateral movement to catch via the mechanical coupling and for example via the sliding portion, and a second position whereat a second portion of the spindle is seated in the vicinity of but mechanically disengaged from the mechanical coupling, for example loosely in place within the recess, and the spindle is thus mechanically disengaged from the catch.

The basic principle of the security mechanism in accordance with the invention is that the handle is disengaged from the catch by disengagement of the spindle portion from the sliding portion. Other than the modifications provided in the spindle, the handle assembly may be essentially of conventional design. In contrast with alternative mechanisms which lock the spindle and/or the handle in some manner, and generally therefore require special locking components, such as grooves, apertures or the like, the present invention allows for the functional de-coupling of handle and latch in admirably simple manner. No complex locking mechanisms are involved: it is merely necessary to make a simple modification to the spindle structure.

The security mechanism in accordance with the present invention is suitable for fitment to any closure, such as a door, window or the like, which is releasably opened by means of a latch closure mechanism operated by a rotating spindle arrangement, which arrangement will be well known. In particular, the mechanism may be incorporated into the handles for operation of domestic doors and windows, whether externally or internally. The mechanism may be incorporated into handles on such doors and windows where such handles are provided on one side only, or where the spindle goes through the thickness of the door to be operated by a handle on both sides. In the latter case, the handle will preferably be so arranged that the spindle is slidably moveable from one side only, in particular from the inside, thereby preventing unauthorised access from the outside.

The spindle in accordance with the invention may be of any suitable size and shape to co-operate with and be received within a recess in a sliding member in suitable mechanical engagement to effect retraction of a catch in use. In accordance with typical designs, the spindle (in the case of the present invention, in the or each first portion adapted to engage the recess) is suitably sized and shaped so as to mechanically bear upon, at least in part, the internal surfaces of the recess within the sliding portion. In particular, most conveniently, the circumferential shape of the spindle, and the circumferential shape of the recess, are generally identical so that the spindle fits snugly therein and bears mechanically upon generally the whole of the inner surface of the recess. For efficient mechanical coupling between spindle and sliding portion, the spindle conveniently has a polygonal cross section, in particular a rectangular cross section, and most preferably a square cross section, to engage a generally correspondingly shaped and sized recess.

The or each second portion then comprises a portion of the length of the spindle laterally spaced from the or each first portion which has been reduced in cross section so as to be able to freely rotate within the recess into which the first portion(s) mechanically engage. For example, a spindle of conventional design may be prepared in conventional manner, and then one or more areas of reduced cross section machined thereon. The precise profile of the second portion(s) of reduced cross section is not important. For convenience of manufacture these may be circular in cross section.

In its broadest aspect the invention comprises the spindle itself adapted to be incorporated within a handle of otherwise relatively conventional design to provide a securing mechanism therewithin. In accordance with the invention the spindle can be supplied separately from the handle and/or as a kit of parts in conjunction with a handle/spindle/catch assembly for use as an optional accessory with a standard handle and/or as an accessory for after-market fitment as a modification to a standard handle assembly already in place upon a door, window or the like.

In a further aspect of the invention there is provided a handle assembly for an openable closure such as a door, window or the like comprising a catch adapted to be received in a suitable recessed socket in a frame of the closure to retain the closure in a closed position, operably linked via a mechanical coupling to a rotatable spindle in such manner that rotation of the spindle draws the catch from the socket to free the closure and allow it to be opened, wherein the spindle is adapted in accordance with the invention as hereinbefore described.

In particular, the spindle is adapted to be received in a recess in the mechanical coupling to effect mechanical engagement therewith and with the catch in use, for example in that the catch is adapted for mounting for linear movement parallel to a surface of the closure, for example by being retained within the thickness of the closure or upon a surface thereof, between a retracted position and an extended position in which it engages a socket within or upon a frame surrounding the said closure to effect closure thereof, a sliding member extending laterally from and mechanically coupled to the catch to translate to and fro therewith, a spindle extending generally perpendicularly to the catch.

The spindle is in accordance with the first aspect of the invention as hereinbefore described, being received in a recess within the sliding member in such manner as to itself be slidable from at least one first position in which the spindle mechanically couples with the recess, and in particular in which a first portion as hereinbefore defined of the spindle engages within the recess such that rotation of the spindle causes retraction of the catch, and at least one second position in which the spindle is mechanically decoupled from the recess, and in particular wherein a second portion as hereinbefore defined of the spindle lies within the recess such that the spindle and sliding member are mechanically decoupled, the handle assembly preferably further comprising a handle means mounted upon a surface of the closure and accessible externally therefrom to effect rotation of the spindle.

A handle assembled in accordance with the second aspect of the invention is thus provided with a simple safety means by which the handle can be mechanically disengaged from the latch such that rotation of the handle does not effect translation of the latch. It can clearly be seen that such an arrangement provides for a simple mechanism by which a handle can be disengaged and unauthorised use prevented.

Disengagement is effected by sliding the spindle in a direction generally perpendicular to the plane of the closure, such that the spindle is selectively mechanically engaged and disengaged with the sliding member. The handle arrangement is preferably adapted to facilitate this, in that it incorporates a release actuator operably, and for example mechanically, linked to the spindle so as to effect sliding of the spindle between its first and second positions to selectively engage and disengage the spindle from the catch. This is preferably accessible externally of the assembly by a user, and more preferably is accessible externally from a single side only, for example being the inside of an external closure such as a house door or window. The handle arrangement is preferably adapted to facilitate this.

At its simplest, a release actuator may be provided in the form of a suitably shaped gripping portion at one or both ends of the spindle, and associated with or projecting beyond the handle in use, to allow the user to slide the spindle in the required direction.

Alternatively, the release actuator may be separate from but operably coupled to the spindle, being provided either similarly within the handle generally about the end of the spindle or elsewhere externally of the closure on which the handle is mounted. In¹ either case the release actuator includes actuation means to facilitate transverse movement of the spindle via a suitable operational coupling. This may for example comprise a series of mechanical couplings, but non-mechanical operational "couplings", for example making use of magnets such as selectively switchable electromagnets, are also in the cope of the invention. Such actuation means to effect sliding of the spindle may be simply mechanically operated, electromechanically operated or the like, and may incorporate suitable security devices, for example in the form of mechanical or electrical locking mechanisms, to prevent their unauthorised operation and/or to restrict operation to authorised persons.

In a preferred embodiment, a release actuator is contained within the handle, and is so positioned to couple mechanically upon the spindle and effect translational movement thereof. For example, the release actuator comprises a shank portion disposed within a suitable cavity in the handle so as to couple mechanically with an adjacent end of the spindle within the completed handle assembly, and a head portion seated within the handle so as to be externally accessible, in such manner that operation of the head portion enables the shank portion to act upon the spindle to cause to and fro movement thereof, and thus enable the spindle to be translated between the said first and second positions.

The shank portion may act to drive the spindle to and fro via any suitable mechanical engagement. For example, as its simplest, an end of the shank portion distal from the head portion may engage with and/or depend directly upon an end of the spindle so that translational movement of the actuator provides corresponding translational movement of the spindle. The shank portion may slide freely within the recess in the handle, or may be mounted therein via a mechanical arrangement, such as screw threading, by means of which rotation of the shank portion tends to urge the shank portion in the said to and fro direction, and effect the said translation of the spindle.

However, in a more preferred embodiment, rather than depending directly upon the spindle, the shank portion is preferably operably coupled to the spindle by a rotational coupling being such that rotation of the actuator, for example by rotation of the head, tends to cause the spindle to drive between the said first and second positions. For example, a threading engagement is provided between the shank of the actuator and an end of the spindle coupled thereto. This can be achieved for example in that an internally threaded recessed end of the spindle receivingly surrounds a complementarily externally threaded projecting end of the shank portion, or in that an internally threaded hollow end of the shank portion receivingly surrounds a complementarily externally threaded projecting end of the spindle. Such a threaded arrangement tends to be more stable and secure, and is easily operated by rotation of the head, which is again suitably adapted for receiving a screwdriving means. The head portion is preferably adapted to facilitate simple user operation of to and fro movement of the actuator, for example in that the head portion includes a gripping portion to allow a user to slide the actuator to and fro, or suitable recesses within the head to drive rotation within the thread as the case may be.

A locking mechanism may be provided in association with the spindle to lock the spindle selectively in the first and/or second positions and prevent lateral movement of the spindle by unauthorised persons. For example the locking mechanism may act to lock the release actuator. Where a release actuator is accessible from or the spindle otherwise operable from either side of the door, a locking mechanism may be provided on either or both sides, and may be such as to lock the spindle entirely, or merely prevent its operation from that side.

The spindle may be provided in any suitable material, such as is conventionally used for spindles of conventional design. For example, the spindle may be fabricated from brass, mild steel or other suitable metallic material, and is initially preferably fabricated in conventional manner to comprise a spindle of single cross section corresponding in extent to the recess in the sliding portion into which the spindle is intended to be received, and is then provided with areas of reduced cross sectional extent by suitable fabrication process such as machining. Other components of the handle are entirely conventional, and will be fabricated from known materials.

In accordance with a further aspect of the invention there is provided a kit of parts comprising a spindle as hereinbefore described, optionally further a spindle of conventional design interchangeable therewith, and a handle, sliding portion and catch of conventional design, suitable to enable the fitment of a handle mechanism embodying the principles of the invention to a closure such as a door, window or the like.

In accordance with a further aspect of the invention there is provided a method of fitment, and in particular fitment as an after-market modification in situ, of a security device in accordance with the above to a closure such as a door, window or the like which is secured by a catch openable by action of the handle via a rotating spindle operably coupled via mechanical coupling to the catch such as to effect movement of the catch between a fastened and a release position, the method comprising the steps of disassembling the handle, fitting a spindle in accordance with the first aspect of the invention (that is, a spindle with at least one first portion having a cross-sectional shape and extent such as to mechanically engage with the mechanical coupling, and at least one second portion laterally spaced from the said first portion of reduced cross sectional extent such as not to mechanically engage with the mechanical coupling) into the handle, so as to be slidable from at least one first position wherein the spindle is mechanically engaged with the catch to at least one second position wherein the spindle is mechanically disengaged therefrom.

The spindle is slidable from at least one first position wherein the first portion is mechanically engaged with the mechanical coupling, for example in a recess therein, in the usual manner and a second position wherein the second portion is located in the vicinity of but mechanically disengaged from the mechanical coupling, for example loosely in a recess therein so that the spindle is free to rotate without operating the catch. No other modification to a handle of conventional design is required. The invention will now be described by way of example only with reference to Figures 1 to 7 of the accompanying drawings wherein:

Figures 1 to 4 illustrate a spindle in accordance with the invention and its use; Figure 5 is an illustration of a suitable handle mounted release actuator to operate the selective engagement/ disengagement of the spindle of figures 1 to 4 in use;

Figures 6 and 7 are alternative versions of the simple release actuator mechanism of figure 5.

Referring first to Figure 1, a spindle in accordance with a first aspect of the invention (A) is shown. The spindle consists of a square brass rod of otherwise conventional design, which has been provided with two areas of reduced cross section (2), serving to define a primary area of full cross section (3) therebetween.

The positioning of the spindle in accordance with the invention within a handle arrangement of conventional design is illustrated schematically in Figures 2 to 4. In each of these Figures, a part of the conventional handle is shown, consisting of a face plate (6) which will in use be mounted on the edge of a door, and a housing (1) containing the sliding mechanism (not shown in detail) by which rotation of the spindle (A) will be transmitted to and cause lateral movement of a catch (not shown) projecting beyond the face plate (6), to retract it and allow the door to be opened in conventional manner.

In Figure 2 the spindle (A) is shown engaged in the "first position", whereat the primary portion (3) of the spindle sits snugly in interference fit within the aperture (7). Rotation of the spindle (A) will bear upon the surfaces of the aperture (7) and thus effect, through suitable mechanical linkages of conventional design, lateral movement of the sliding portion within the housing (1) and consequently retraction of the latch or bolt in conventional manner.

Operation of the security mechanism incorporated into the spindle (A) is shown in Figures 3 and 4. To disengage the handle from the latch, the spindle (A) is slid laterally, for example in the direction of the arrow (4), until a secondary portion (2) seats within the aperture (7). In this position, the spindle (A) is freely rotatable in the direction of the arrows (5) without acting mechanically upon the walls of the aperture (7), and consequently is mechanically de-coupled from the sliding portion and the latch. In this position therefore, operation of the handle does not effect operation of the latch, and the door is secured against unauthorised opening in simple, stable and effective manner.

A release mechanism for use with a spindle in accordance with the invention, which serves selectively to engage/ disengage the spindle from the latch operating mechanism, and thus selectively to unlock/ lock the handle, is illustrated in three alternatives in Figures 5 to 7.

A simple suitable arrangement is shown in Figure 5. A handle (41) is illustrated of generally conventional design, in that it comprises a shaft portion (42) having a lever portion (43) mounted generally at a first end of the shaft portion, such that operation of the lever will cause the shaft to rotate. A distal end of the shaft portion is hollow to receive a spindle in conventional manner. In the illustrated examples of Figures 5 to 7, a lever handle is envisaged, but the skilled person will readily appreciate that the principles could be applied to handles where the shaft was turned by other means, for example in that a rotatable knob was mounted about the shaft. In a modification to the handle, not only is the distal end of the shaft (42) hollowed to receive the spindle, but the shaft has a full through bore, with an aperture (44) at the lever end. The aperture (44) receives a release actuator in the form of a release screw (45), which is illustrated in isometric view in Figure 5B, and shown received within the shaft (42) of the handle (41) (the latter being shown in cross section) in Figure 5C.

The release screw comprises a head (49) and a shank having a threaded portion (46) and forward extension (47). The threaded portion is received in a tapped portion (48) of the bore (44) within the shaft (42) of the handle.

In use, to operate the release mechanism, the release screw is rotated, and the action of the threaded portion (46) within the tap portion (48) of the through bore in the shaft (42) causes the release screw to move to and fro therewithin. The head (49) is provided with a slot (50) to receive a means to drive the screw. Alternative head arrangements might be appropriate.

The spindle is illustrated in Figure 5D. The spindle is fabricated from steel, and the major part of it (51) comprises a square, 7.15 mm section. A 4 millimetre wide portion of reduced cross sectional extent is machined down to a 6 mm generally circular portion. This serves in use as the said second spindle portion, which when in position surrounded by the recess in the mechanical coupling of the latch mechanism as illustrated in Figures 1 to 4 serves to disengage the spindle from the recess, and allow the spindle to freely rotate independently of the latch. The part of the body (51) immediately adjacent to the second portion (52) serves in use as what is referred to herein as the first spindle portion, on which the recess will engage with the spindle and thus the spindle will operate the latch. Thus, it can be seen that to and fro movement of the spindle will move it from a position where it is capable of engaging the recess and operating the latch to a position where it cannot engaging the recess and operate the latch, in this latter position thus effectively locking the handle.

In the embodiment of Figure 5, this movement is effected simply by operation of the release screw. The release screw is mounted in the axial bore (44) within the shaft (42). The spindle is similarly mounted in an axial bore within the shaft (42) at an opposite end. Spindle and release screw are therefore coaxially mounted within the shaft. They are mounted with a direct mechanical coupling such that operation of the release screw in the manner above described to drive the forward extension thereof to and fro (47) in engagement with and so serving to drive the spindle and effect the engagement/disengagement above described.

Figures 6 and 7 illustrate more sophisticated variations of the principles of Figure 5. Again, a release screw is mounted within a bore in the lever end of the shaft of the handle, so as to be coaxially mounted with the spindle, received in a corresponding axial bore at the distal end of the shaft. However, the mechanical coupling between a forward extension of the release screw and a correspondingly coupled end of the shaft is different, in both cases comprising a threading engagement.

In the first example of Figure 6 (being the most preferred alternative), a release screw is illustrated in Figure 6 A which has a head (59), again slotted to facilitate rotation in situ by means of the slot (not shown), and a shank (55), in this case the forward part of which (56) is threaded. This is adapted for use in conjunction with the spindle (60) illustrated in cross section in Figure 6B. The spindle (60) again has a body (61) of 7.15 mm square cross section, with a machined reduced cross sectional portion (62). In this instance however, the spindle at an end (63) proximal to the handle and release button in use has a threaded recess (64). The recess (64) receivingly and threadingly engages the forward threaded portion (56) of the release screw in Figure 6 A. The release screw is free to rotate within the bore in the handle shaft, such that rotation of the release screw tends, via the thread and tap arrangement (56, 64) to draw the spindle (60) to and fro.

The alternative arrangement in Figure 7operates the same general principle. In this instance however, the release screw illustrated in cross section in Figure 7 A itself has an end portion (71) having a threaded recess (72) which surroundingly engages a threaded end (73) of the spindle in Figure 6b. The spindle of Figure 7B is otherwise equivalent to the earlier spindles, having a second portion of reduced cross section, and the action of the screw threading is such that when the release screw is actuated the spindle is drawn to and fro to engage/disengage the latch mechanism.

In accordance with the invention therefore an admirably simple potentially key free lock mechanism with simple action that requires little modification to, and operates alongside the principles of, conventional closure handles, is provided.

Claims

1. A security mechanism for a handle assembly of an openable closure such as a door, window or the like, which handle assembly comprises a catch adapted to be received in a suitable recessed socket in a frame of the closure to retain the closure in a closed position, operably linked via a mechanical coupling to a rotatable spindle in such manner that rotation of the spindle draws the catch from the socket to free the closure and allow it to be opened, wherein the security mechanism comprises a spindle for use in such an assembly characterised in that it has at least one first portion having a cross-sectional shape and extent such as to mechanically engage with the mechanical coupling such that rotation of the spindle acts upon the catch, and at least one second portion laterally spaced from the said first portion being of reduced cross sectional extent such that it does not mechanically engage with the mechanical coupling and the spindle does not act upon the catch.

2. A security mechanism in accordance with claim 1 wherein the spindle is adapted to be slideable between a first position whereat a said first portion of the spindle is engaged in use with the mechanical coupling, and rotation of the spindle serves to cause lateral movement to the catch, and a second position whereat a second portion of the spindle is seated in the vicinity of but mechanically disengaged from the mechanical coupling, thus disengaging the spindle from the catch.

A security mechanism in accordance with claim 2 wherein the spindle is adapted to be received in a recess in the mechanical coupling to effect mechanical engagement therewith in use, and to be slideable between a first position whereat the first portion of the spindle is engaged snugly with the recess and a second position whereat a second portion of the spindle is seated loosely in place within the recess, and the spindle is thus mechanically disengaged from the catch.

4. A security mechanism in accordance with claim 3 wherein the circumferential shape of the spindle, and the circumferential shape of the recess, are generally identical so that the spindle fits snugly therein and in use bears mechanically upon generally the whole of the inner surface of the recess.

5. A security mechanism in accordance claim 4 wherein the spindle has a square cross section, to engage a generally correspondingly shaped and sized recess.

6. A security mechanism in accordance with any preceding claim so arranged that the spindle is slidably moveable from one side only, in particular from the inside of a closure, thereby preventing unauthorised access from the outside.

7. A security mechanism for use with the handle of a closure comprising a spindle in accordance with any preceding claim supplied separately from the handle and/or as a kit of parts in conjunction with a handle/spindle/catch assembly for use as an optional accessory with a standard handle and/or as an accessory for after-market fitment as a modification to a standard handle assembly already in place upon a door, window or the like.

8. A handle assembly for an openable closure such as a door, window or the like comprising a catch adapted to be received in a suitable recessed socket in a frame of the closure to retain the closure in a closed position, operably linked via a mechanical coupling to a rotatable spindle in such manner that rotation of the spindle draws the catch from the socket to free the closure and allow it to be opened, the spindle being in accordance with any preceding claim and being mounted in associated with the mechanical coupling in such manner as to be slidable whereat a said first portion of the spindle is engaged in use with the mechanical coupling, and rotation of the spindle serves to cause lateral movement to the catch, and a second position whereat a second portion of the spindle is seated in the vicinity of but mechanically disengaged from the mechanical coupling, thus disengaging the spindle from the catch.

9. A handle assembly in accordance with claim 8 comprising a catch adapted for mounting for linear movement parallel to a surface of the closure between a retracted position and an extended position in which it engages a socket within or upon a frame surrounding the said closure to effect closure thereof, a sliding member extending laterally from and mechanically coupled to the catch to translate to and fro therewith, a spindle extending generally perpendicularly to the catch, the spindle being in accordance with any preceding claim and being received in a recess within the sliding member in such manner as to itself be slidable from at least one first position in which a first portion of the spindle engages within the recess such that rotation of the spindle causes retraction of the catch, and at least one second position in which a second portion of the spindle lies within the recess such that the spindle and sliding member are mechanically decoupled.

10. A handle assembly in accordance with claim 9 comprising a release actuator operably linked to the spindle so as to effect sliding of the spindle between its first and second positions to selectively engage and disengage the spindle from the catch.

11. A handle assembly in accordance with claim 10 wherein the release actuator comprises a suitably shaped gripping portion at one or both ends of the spindle associated with or projecting beyond the handle in use, to allow the user to slide the spindle in the required direction.

12. A handle assembly in accordance with claim 10 wherein the release actuator release actuator is separate from the spindle, received within the handle so positioned as to couple mechanically upon the spindle and effect translational movement thereof.

13. A handle assembly in accordance with claim 12 wherein the release actuator comprises a shank portion disposed within a suitable cavity in the handle so as to couple mechanically with an adjacent end of the spindle within the completed handle assembly, and a head portion seated within the handle so as to be externally accessible, in such manner that operation of the head portion enables the shank portion to act upon the spindle to cause to and fro movement thereof, and thus enable the spindle to be translated between the said first and second positions.

14. A handle assembly in accordance with claim 13 wherein a threading engagement is provided between the shank of the actuator and an end of the spindle coupled thereto such that rotation of the actuator tends to cause the spindle to drive between the said first and second positions.

15. A handle assembly in accordance with claim 14 wherein an internally threaded recessed end of the spindle receivingly surrounds a complementarily externally threaded projecting end of the shank portion to effect the threading engagement.

16. A handle assembly in accordance with one of claims 8 to 15 further compressing a locking mechanism in association with the spindle to lock the spindle selectively in the first and/or second positions and prevent lateral movement of the spindle by unauthorised persons .

17. A method of fitment, and in particular fitment as an after-market modification in situ, of a security device to a closure such as a door, window or the like which is secured by a catch openable by action of the handle via a rotating spindle operably coupled via mechanical coupling to the catch such as to effect movement of the catch between a fastened and a release position, the method comprising the steps of: disassembling the handle, fitting a spindle with at least one first portion having a cross-sectional shape and extent such as to mechanically engage with the mechanical coupling, and at least one second portion laterally spaced from the said first portion of reduced cross sectional extent such as not to mechanically engage with the mechanical coupling, so as to be slidable from at least one first position wherein the spindle is mechanically engaged with the catch to at least one second position wherein the spindle is mechanically disengaged therefrom.