GB2486473A

GB2486473A - Locking Mechanism

Info

Publication number: GB2486473A
Application number: GB201021357A
Authority: GB
Inventors: Nigel Philip Shenton
Original assignee: Window Fabrication and Fixing Supplies Ltd
Current assignee: Window Fabrication and Fixing Supplies Ltd
Priority date: 2010-12-16
Filing date: 2010-12-16
Publication date: 2012-06-20
Anticipated expiration: 2030-12-16
Also published as: GB201021357D0; GB2486473B

Abstract

A locking mechanism 10 for a closure, said mechanism comprising an elongate slider arm 14 arranged in use to be actuated in a direction substantially parallel with its longitudinal axis. A locking cam 20 is coupled to the slider arm 14 for actuation thereby in said actuation direction between unlocked and locked conditions. A guide 32 is provided for constraining motion of the cam 20, wherein the guide comprises a deflector 44 which is obliquely angled relative to the actuation direction such that upon actuation of the slider arm into the locked condition the cam 20 rides up the deflector 44 and thereby extends in a direction substantially perpendicular to the longitudinal axis of the slider arm. A locking arm may also be provided with the mechanism. A plurality of locking mechanisms may be provided to form a locking assembly.

Description

Locking Mechanism The present invention relates to a locking mechanism for a closure and more particularly, although not exclusively, to a locking mechanism which may be actuated by operation of a handle.

Multipoint locking mechanisms provide for locking engagement between a closure and associated frame at a plurality of spaced locations along a closure edge.

A conventional style of multipoint locking mechanism relies on actuation of one or more slider bars to move a plurality of cam members in a direction parallel with the edge of the closure. This sliding motion allows the cams to move laterally into engagement with one or more slot formations in the opposing frame and thereby hold the closure fast against the frame. In this type of arrangement, the cams hold the closure against the frame so as to prevent opening of the closure in a direction substantially perpendicular to the direction of travel of the cams.

The reverse actuation of the slider bar(s) moves the cams out of the slot formations so as to allow movement of the closure edge away from the frame.

There exist potential problems with multipoint locking arrangements of this kind.

For example, in order to attempt to force entry into premises, a trespasser will typically try to prise open a window using a lever. The prising of a closure in this manner forces the closure edge and opposing frame apart in a direction within the plane of the closure. If the closure edge and frame are sufficiently separated, the cam can be pulled clear of the slot in a direction perpendicular to the normal actuation of the cam to allow the closure to be forcibly opened.

For this reason, it is important that the closure and associated frame are closely fitted so that there is as little freedom of movement of the closure within the frame as possible. It is also important that depth of the cam within the slot is such that the cam cannot easily be prised out.

However the close fitment of the closure in the frame and the elongate nature of the cam can cause the cam to catch against the frame when the cam is retracted from the slot in order to allow the closure to be opened. This is a particular problem for small or narrow closures since, as the closure is moved away from its closed position against the frame, the angle of opening changes rapidly and causes the likelihood of the cam catching on the frame to increase. In such instances, the installation of the closure often requires the installer to experiment with the position of the closure in the frame to achieve a desired opening action.

However this can negatively impact the quality of the seal achieved between the closure and frame.

In view of the above problems, there is a practical limit on the height of the cam, meaning that there is an associated limit on the degree to which the locking mechanism can resist prising of the closure.

It is an aim of the present invention to provide a locking mechanism for which the above problems are mitigated in order to provide a more effective locking/opening operation.

According to a first aspect of the present invention there is provided a locking mechanism for a closure, said mechanism comprising: an elongate slider arm arranged in use to be actuated in a direction substantially parallel with its longitudinal axis; a locking cam coupled to the slider arm for actuation thereby in said actuation direction between unlocked and locked conditions; and a guide for constraining motion of the cam, wherein the guide comprises a deflector which is obliquely angled relative to said actuation direction such that upon actuation of the slider arm into the locked condition the cam rides up the deflector and thereby extends in a direction substantially perpendicular to the longitudinal axis of the slider arm.

The locking mechanism may be for a closure having opposing faces and a peripheral edge there-between. The slider arm may be arranged in use to be actuated in a direction substantially parallel with the peripheral edge of the closure.

Typically the closure is mounted within a closure frame such that the peripheral edge of the closure can be moved between a closed position -in which the peripheral edge is immediately adjacent or touching an opposing frame member -and an open condition -in which the peripheral edge is spaced from the opposing frame member.

In one embodiment the slider arm and cam are arranged to be mounted in the same of either the closure or a closure frame member. Preferably the slider arm, cam and guide are arranged to be mounted in the same of either the closure or the closure frame member.

Typically a retaining formation is arranged to be mounted in the other of the closure and closure frame member. The retaining formation may take the form of an abutment a recess or an open-ended slot or groove.

The guide may comprise one or more walls. The guide may comprise a base and one or more side walls depending there-from. The guide may comprise opposing side walls in the form of a channel. The cam may be disposed between said opposing side walls. The guide may be substantially U-shaped in cross section.

S

The deflector may be obliquely angled relative to the slider arm. The deflector may be angled between 5° and 45° relative to the slider arm and/or direction of actuation. Preferably the deflector is angled between 5° and 25° relative to the slider arm and/or direction of actuation. Preferably the deflector is angled between 10° and 20° relative to the slider arm and/or direction of actuation.

In one embodiment, the deflector comprises a slot in one or more side walls of the guide. The deflector may comprise a slot in each opposing side wall of the guide.

Additionally or alternatively the deflector may comprise a ramp or wedge arranged in the actuation path of the cam. The deflector may have first and second opposing portions which may be edges or faces. Motion of the cam may be constrained by said first and second portions. The cam may ride against a first portion when being actuated into the locked condition. The cam may ride against the second portion when being actuated into the unlocked condition.

The cam may comprise a carriage portion and a locking member. The carriage portion may be shaped for cooperation with the deflector. The carriage portion may comprise protrusions on opposing sides thereof arranged to be received in slots in the guide side walls. The protrusions may be generally circular in plan or cylindrical in shape.

The deflector may constrain the cam to rectilinear motion only.

The locking mechanism may comprise a plate member having a slot therein for reception of the cam. The slider arm and guide may be mounted to one side of the plate member and the cam may protrude from the opposing side of the plate member through the slot. The guide may be mounted to the mounting plate via mounting formations which may comprise tab and slot arrangements.

The cam may comprise a head and a neck portion and may take the form of a so-called mushroom cam'. The head portion may be wider than the neck portion.

The locking mechanism may further comprise a locking arm arranged for pivoting or rotational motion. The locking arm may be pivotally mounted to the guide.

The locking arm may comprise one or more protrusions on opposing sides thereof which engage with openings in opposing side walls of the guide. The protrusions may be provided by way of a through rod or pin about which the locking arm can rotate in use. The guide openings may be substantially circular in plan.

The slider arm may engage the locking arm at a location spaced from its axis of rotation. Actuation of the slider arm may cause rotation of the locking arm into and from a locking condition. The locking arm and cam may move concurrently between locked and unlocked conditions under the actuation of the slider arm.

This may provide a dual locking action.

The slider arm may have an opening or slot therein to receive the locking arm. The locking arm may have a curved edge for engagement with an edge of the slider arm slot. The locking arm may be arranged to pass through the slot in the plate member.

A locking assembly comprising the locking mechanism may comprise an actuator which may be a manual or powered actuator. The actuator may comprise a handle. The actuator may comprise an actuator mechanism for converting an input torque into a rectilinear motion of the slider arm.

En one embodiment the locking assembly takes the form of a multipoint locking assembly. The locking assembly may comprise a plurality of cams and/or locking mechanisms spaced along the peripheral edge of the closure or the corresponding closure frame member. Each mechanism may comprise a cam and guide arrangement. The assembly may comprise a single slider arm serving multiple locking mechanisms. The assembly may comprise a plurality of slider arms.

The actuator may actuate a first slider arm in a first direction and a second slider arm in an opposing direction. Accordingly the cam of a first locking mechanism may be actuated in a first direction and the cam of a second locking mechanism may be actuated in an opposing direction. Alternatively first and second cams of respective first and second locking mechanisms within the locking assembly may be actuated in the same direction.

First and second locking mechanisms may be correspondingly or else opposingly aligned.

According to a further aspect of the invention, there is provided a closure comprising the locking mechanism or locking assembly of the above aspects.

Whilst the term cam' is used herein to refer to the locking member of the locking mechanism, it will be appreciated that such term could be substituted with the term bolt' or similar.

Working embodiments of the present invention are described in further detail below with reference to the accompanying drawings, of which: Figure 1 shows an exploded three-dimensional view of a locking mechanism according to one embodiment of the present invention; Figure 2 shows a longitudinal section through a multipoint locking mechanism incorporating the locking mechanism of Figure 1; Figures 3A and 3B show three dimensional views of a locking assembly according to the present invention in respective unlocked and locked conditions; Figures 4A and 4B show part-cut-away side views of the locking assembly of figure 3 in respective unlocked and locked conditions; and, Figures SA and SB show part-cut-away side views of a locking assembly according to a further embodiment of the present invention in respective unlocked and locked conditions; The present invention may be considered to derive from the determination by the inventor that the locking cams can be actuated in a direction which is oblique to the sliding action of the actuator arm so as to provide for an improved locking action. This is counter-intuitive with reference to cam-type locking mechanisms which are actuated in a constrained sliding manner.

The present invention is particularly suited to closures in the form of windows, typically for domestic or commercial premises. However the present invention may potentially be applied to other types of closure for which multipoint locking systems are used, such as for example, internal or external doors or the like.

Turning to Figure 1, there is shown an exploded view of a locking mechanism 10 according to one embodiment of the present invention. The mechanism 10 generally comprises a slider arm 12 located beneath a cover plate 14 and longitudinally aligned therewith. The cover plate 14 is arranged in use to be located in a closure so as to provide a peripheral edge or face of the closure, which is arranged to be locked with respect to a closure frame.

The slider arm has an abutment/end section 16 which is shaped for engagement with a carriage member in the form of cam slider 18.

The cam slider 18 is shaped to carry cam 20. In this regard, the cam slider 18 has a recess 22, into which a correspondingly shaped cam end portion 24 is insertable so as to be held therein. The end portion 24 may comprise a pin member which extends into the cam mid or body portion 26 such that the cam can rotate relative to the slider 18. Once connected in this manner, the cam 20 and can slider 18 form a sub-assembly which may be referred to herein as a cam assembly.

The cam 20 has a narrower mid or neck region 26 and a wider head end 28.

The cover plate 14 has an elongate slot 30 which is generally rectangular in shape.

The slot 30 has a chamfered or bevelled edge around its perimeter.

The cam neck region 26 is located within the slot with the cam slider 18 to one side of the cover plate and the cam head 28 positioned on the opposing side of the cover plate 14.

A guide member 32 is attachable to the cover plate so as to constrain motion of the cam slider 18 therein. The guide member 32 is formed of sheet metal which is bent to form an elongate channel which is generally U-shaped in cross section.

The guide member 32 has opposing side walls 34 and 36 which are spaced by a base portion 38. The elongate edges of the side walls 34 and 36 each comprise connection formations in the form of tabs 40 which are shaped and located to engage with corresponding slots 42 in the cover plate 14.

The guide member 32 and cover plate 14, once connected via the tab 40 and slot 42 formations, form a rigid assembly.

The guide member 32 has elongate slots 44 cut out of each opposing side wall 34, 36. The slots 44 in each side wall are aligned and are obliquely angled relative to the base 38 and/or cover plate. En this embodiment, the acute angle formed between the axis of the elongate slots and the base 38 or cover plate 14 is approximately 15°, although other angles in the region of 100 to 20° or even 50 to 40° may be suitable to enable operation as will be described below.

The cam slider 18 has an outwardly depending protrusion 46 on opposing sides thereof which protrusions are arranged to engage in respective slots 44 in the guide member side walls 34 and 36.

The guide member has further openings 48 in side walls 34 and 36, which are shaped to receive the locking arm pin 50 as will be described below.

Locking arm 52 has a pin or shaft member 50 running through a bore therein. The locking arm has a hub section shaped to traverse the width of the guide member (i.e. between side walls 34 and 36). The locking arm itself is narrower than the guide member. The pin 50 is arranged to be located in openings 48 in the guide member side walls 34 and 36 at a position spaced along the length of the guide member from the slots 44. Thus the locking arm and cam slider 18 are aligned alongtheguide.

The slider arm 12 when assembled for use extends part way along the guide member 32 between the side walls 34 and 36 such that its free end 16 abuts and engages with the cam slider 28. The cam slider has a recess for receiving the slider arm end formation in this regard.

The slider arm has an opening or slot 54 therein which is substantially rectangular in form. The slot 54 is shaped to accommodate the locking arm 52 which can pass there-through. The slot 54 is at least in part aligned with the cover plate slot 30 such that the locking arm 52 can pass through both slots 30 and 54 in a single locking action as will be described below.

The guide side walls 34 and 36 are provided with internally-extending locating flanges 56, on which the slider arm rests. These flanges 56 ensure correct alignment of the slider arm in the guide for operation.

Turning now to Figure 2, there is shown a pair of locking mechanisms 10 located at spaced locations along a single cover plate 14. These mechanisms 10 may be actuated by a single slider bar 12 having multiple abutment formations 16 along its length. Alternatively a plurality of slider bars 12 may be provided in an end to end alignment such that multiple locking mechanisms 10 can be actuated simultaneously.

In Figure 2, the locking mechanisms are shown in a rest or unlocked condition in which the cam slider 18 is at the end of the slots 44 which is furthest from the cover plate 14. That is to say the cam 20 is in a retracted position with respect to the cover plate 14. In this condition, the locking arm 52 is rotated such that it is also retracted within the slot 30 in the cover plate.

In Figures 3 and 4, there is shown a multipoint locking assembly 60 comprising locking mechanisms 10 as described above. Like numerals are used to denote like components or sub-assemblies and will not be described again for conciseness.

The locking assembly 60 comprises an actuator 62 mounted to the cover plate 14 between the spaced locking mechanisms 10. The actuator 62 comprises a conventional mechanism located in housing 64 and will not be described in detail.

In this particular embodiment, the actuator input member 66 is a barrel arranged to be actuated by a handle in a conventional manner. The actuator 62 mechanism converts the rotational input torque into a rectilinear, sliding motion of the slider bar 12 for example by way of a rack and pinion arrangement or else by way of a pivoting barrel arm engaging in a corresponding slot in the slider bar.

Whilst a manually operated handle is considered the most widely adopted embodiment, various other actuation arrangements are possible within the scope of the present invention, such as, for example, an arrangement in which the barrel is driven by an electric motor between locked and unlocked conditions.

Alternatively, a sliding handle arrangement as opposed to a pivoting handle, may be used.

The slider bar 12 is actuated in the direction of arrow A in Figure 3, that is in a direction substantially parallel with the length of the cover plate 14 and/or the peripheral edge of the closure in which the locking assembly is mounted.

Motion of the slider bar in this direction causes the edge of slider bar slot 54 to contact with the curved face of locking arm 52, thereby causing the locking arm to ride up the slider bar and pivot about pin 50 such that it protrudes through cover plate slot 42. Simultaneously the slider bar abutment formation 16 pushes the cam slider 18 in a longitudinal direction along the guide 32. The cam slider protrusions 46 ride up the obliquely aligned guide slots 44, so as to cause a component of the motion of the cam 20 to be in a direction perpendicular to that of the arrow A, that is, in the direction of arrow B in figure 3.

Thus as the cam 20 moves along the cover plate slot 42, it also extends outwardly there-from into the locked or actuated condition as shown in Figure 3B and 4B.

This action increases the depth to which the cam extends into an associated keeper formation, such as a slot or the like, in an adjacent closure frame. This can increase the security of locking.

The cam 20 can rotate against a retaining formation against which the closure is locked. In this regard the cam may rotate about the pin 24 relative to the cam slider 18 and/or other members of the locking mechanism. The cam is thus translated during locking/unlocking relative to its axis of rotation. The cam may be eccentrically mounted on the pin 24 such that it is pressed against the retaining formation during the locking action. The can help to improve the closeness of the fitment between the closure and associated frame.

The direction of actuation of actuator 66 is simply reversed to return the locking mechanisms 10 to their original at rest condition. In this embodiment, a reverse torque is applied by the handle (not shown) to unlock the closure. When unlocked, the cams 20 and locking arms 52 are simultaneously retracted, thus allowing the closure clearance from the adjacent closure frame in order to allow the closure to be opened. It will be appreciated that when the cam slider 18 is retracted by the slider arm 12 in an unlocking direction, it rides against the opposing edge of the guide slot 44 to that of the locking motion. Thus the guide slot constrains motion of the cam to rectilinear motion only.

Turning now to Figure 5, there is shown a further embodiment of the present invention in which the different locking mechanisms are simultaneously actuated in opposing directions. In such an assembly 100, the components and operation are substantially as described above, save that a first locking mechanism 110 is arranged in an opposite orientation or attitude to that of the second locking mechanism 112. Accordingly each locking mechanism is arranged such that it is akin to a mirror image of the other mechanism.

The assembly 100 also differs from the earlier embodiment 60 in that a pair of slider arms 114 and 116 is provided. When the actuator 118 is operated, slider arm 114 is actuated in the direction of arrow C, whilst slider arm 116 is actuated in the direction of arrow D, that is to say, in opposite directions. Accordingly the cams and locking arms of the mechanism each travel in a direction away from the actuator 118 in the locking direction.

Such opposing actuation of slider arms 114 and 116 can be achieved in a conventional manner, for example by providing a toothed wheel between opposing toothed faces of the slider arms within the actuator housing.

In the above embodiments, component parts are typically formed of metal although it is possible that plastic may be used for certain components where material properties permit.

Whilst the above embodiments are described as though the locking mechanism and associated actuator are mounted within the movable closure, it will be appreciated that the mechanism and actuator could equally be provided in the closure frame. In either arrangement, the other of the closure or frame will typically comprise a keeper formation, such as a slot, flange or other such formation for maintaining secure contact with the cam in the locked condition. For multipoint locks, a plurality of such keeper formations will be spaced along the relevant edge in a manner which corresponds to the cam spacing on the closure or frame.

The closure and/or frame are provided with correspondingly shape recesses and/or fixing formations for location of the actuator mechanism, locking mechanisms and cover plate as will be understood by the skilled person.

Claims

Claims: 1. A locking mechanism for a closure, said mechanism comprising: an elongate slider arm arranged in use to be actuated in a direction substantially parallel with its longitudinal axis; a locking cam coupled to the slider arm for actuation thereby in said actuation direction between unlocked and locked conditions; and a guide for constraining motion of the cam, wherein the guide comprises a deflector which is obliquely angled relative to said actuation direction such that upon actuation of the slider arm into the locked condition the cam rides up the deflector and thereby extends in a direction substantially perpendicular to the longitudinal axis of the slider arm.
2. A locking mechanism according to claim 1, wherein the guide comprises opposing side walls in the form of a channel, the cam being constrained between said opposing side walls.
3. A locking mechanism according to claim 2, wherein the deflector comprises a slot in one or more of said side walls.
4. A locking mechanism according to claim 3, wherein the cam comprises one or more protrusions for location within the one or more slots.
5. A locking mechanism according to any preceding claim, wherein the deflector is angled between 100 and 20° relative to the longitudinal axis of the slider arm.
6. A locking mechanism according to any preceding claim wherein the deflector is shaped to constrain the cam to rectilinear motion only.
7. A locking mechanism according to any preceding claim, wherein the slide arm, cam and guide are all mounted relative to a plate member, the plate member having an opening therein for reception of the cam.
8. A locking mechanism according to claim 7, wherein the guide is mounted to one side of the plate member such that the cam protrudes there-from through the opening to the opposing side of the plate member.
9. A locking mechanism according to claim 7 or 8, wherein the guide is mounted to the plate member via mounting formations which comprise a tab and slot arrangement.
10. A locking mechanism according to any preceding claim, further comprising a locking arm arranged for pivoting motion upon actuation by the slider arm.
11. A locking mechanism according to claim 10, wherein the locking arm is pivotally mounted to the guide such that the locking arm and cam are actuated between unlocked and locked conditions concurrently by movement of the slider arm.
12. A locking mechanism according to claim 10 or 11, wherein the slider arm has an opening therein to accommodate movement of the locking arm.
13. A locking assembly comprising a plurality of locking mechanisms according to any one of claims 1 to 12 and an actuator for imparting rectilinear motion to the or each slider arm.
14. A closure or closure frame comprising a locking mechanism according to any one of claims 1 to 12.
15. A locking mechanism or assembly substantially as hereinbefore described with reference to the accompanying drawings.