EP3976912B1

EP3976912B1 - A cam arrangement

Info

Publication number: EP3976912B1
Application number: EP20728544.6A
Authority: EP
Inventors: Robert Rossall; Simon Golder
Original assignee: Gretsch Unitas GmbH Baubeschlaege; Gretsch Unitas Ltd
Current assignee: Gretsch Unitas GmbH Baubeschlaege; Gretsch Unitas Ltd
Priority date: 2019-05-31
Filing date: 2020-05-18
Publication date: 2024-11-06
Anticipated expiration: 2040-05-18
Also published as: GB201907741D0; WO2020240156A1; GB2584332A; GB2584332B; EP3976912A1; CN114008285A; CN114008285B

Description

Technical Field of the Invention

The present invention relates to a cam arrangement and specifically to a cam arrangement for a lock mechanism such as a lock mechanism for a door or window.

Background to the Invention

Cams are used in lock mechanisms for closures such as windows and doors. Generally, they provide a point of contact or engagement with a corresponding slot or aperture, for example in a frame associated with the window or door. The cam may operate under the operation of a handle. For example, the cam may rotate or move linearly under the operation of the handle to engage with the slot or aperture.
Conventionally, cams of this type are typically provided in two separate sizes, 7.7mm and 9mm (measured with reference to the distance the cams project from a support member of the lock mechanism).
United Kingdom Patent No. GB2124291 discloses a fastener for sliding doors or windows, the fastener comprising a bolt assembly adapted to co-operate with a receiver assembly operable by an actuator under the control of a handle, the bolt assembly including a sprung loaded headed bolt arranged to be received within aligned openings in two overlying rails of the receiver assembly, and on rotation of the handle the actuator slides a retainer one of the rails relative to the other rail to engage and hold the bolt head.
United Kingdom Patent No. GB2322905 discloses a longitudinally-displaceable transmission bar of a shoot bolt mechanism, for a window or door, comprises a laterally projecting locking member arranged to become engaged with a keep, the keep being secured to a fixed frame member opposing an edge member of the openable door or window. The locking member comprises a sleeve which is retained on a stud which projects from the transmission bar, a compression coil spring being retained between a head flange of the stud and an inner end flange of the sleeve to urge the sleeve inwardly towards the transmission bar. A head flange of the sleeve, at its outer end, is arranged to slide beneath spaced retaining flanges of the keep when the locking member is introduced into engagement with the keep. A further cam arrangement is known from US 6 817 637 B .
It would be advantageous to provide a cam arrangement which includes a cam which can be adjusted between these two conventional sizes as necessary.
It is an aim of an embodiment or embodiments of the invention to overcome or at least partially mitigate problems associated with the prior art.

Summary of the Invention

According to an aspect of the invention there is provided a cam arrangement for a lock mechanism of a closure, the cam arrangement being configured to be mounted on a supporting member of the lock mechanism, the supporting member having an upper surface and an opposed lower surface, the cam arrangement comprising a cam which is moveable between a first axial position at which the cam, when mounted to the supporting member of the lock mechanism, projects a first distance from the upper surface of the supporting member and a second axial position at which the cam, when mounted to the supporting member of the lock mechanism, projects a second distance from the upper surface of the supporting member against a biasing force provided by a biasing member, the second distance being greater than the first distance wherein the cam arrangement is configured such that, in use, the biasing member is provided in an abutting relationship with the lower surface of the supporting member.
Advantageously, a cam arrangement may be provided where the cam can be moved between two axial positions. Advantageously, a single type of cam arrangement can be provided which covers both cam sizes conventionally used in applications of this type. Providing a biasing member to move the cam allows for the cam to be automatically reset to one of the two axial positions.
The cam arrangement may be configured such that, in use, the biasing member is provided in an abutting relationship with a surface of the supporting member. The biasing member may be provided in an abutting relationship with a lower surface of the supporting member. The biasing member may be provided in an abutting relationship with the surface of the supporting member and a surface of the cam or a surface of a further component of the cam arrangement. The biasing member may be compressed between the surface of the supporting member and the surface of the cam or surface of the further component of the cam arrangement upon movement of the cam from the first axial position to the second axial position.
In embodiments, the first axial position comprises a position at which the cam, when mounted to the supporting member of the lock mechanism, projects a first distance from a surface of the supporting member. The second axial position comprises a position at which the cam, when mounted to the supporting member of the lock mechanism, projects a second distance from the surface of the supporting member.
The second distance is greater than the first distance. The first distance may be approximately 7.7mm. The second distance may be up to 10.0mm, for example approximately 9.0mm. Advantageously, at each axial position the size of the cam (i.e. the distance it projects from the supporting member) may be substantially equal to one of two standard sizes. The cam arrangement of the invention may therefore be used in applications requiring either a conventional 7.7mm cam or a 9.0mm cam.
It is noted that other cam sizes are envisaged and are dependent on the operating requirements of the cam arrangement which may encompass a range of different distances.
The cam is moveable from the first axial position to the second axial position against the biasing force provided by the biasing member. In such embodiments, the cam is moveable from the second axial position to the first axial position with the biasing force provided by the biasing member. In use, the cam may be pulled against the biasing force provided by the biasing member from the first axial position to the second axial position. For example, the cam may be pulled against the biasing force as a result of the cam engaging with a corresponding slot or aperture in a frame of the closure.
The biasing member may comprise a compressible biasing member, and the biasing force provided by the biasing member may arise via compression of the biasing member. In such embodiments, the cam may be moved against the biasing force provided by the biasing member by compressing the biasing member. The compressible biasing member may comprise a resilient material, or may comprise a spring, for example. In some embodiments the biasing member comprises a washer. The washer may be a spring washer such as a Belleville washer, a curved disc spring washer or a wave washer, for example.
In some embodiments the biasing member comprises an extendable biasing member, and the biasing force provided by the biasing member may arise via extension of the biasing member. In such embodiments, the cam may be moved against the biasing force provided by the biasing member by extending the biasing member. The extendable biasing member may comprise a resilient material, or may comprise a spring, for example.
In some embodiments the cam arrangement may comprise a spacer with which the biasing member may be operably connected to. For example, the biasing member may be positioned in an abutting relationship with the spacer. The spacer may be integrally formed with a portion of the cam arrangement.
Where the biasing member comprises a compressible biasing member, the biasing member may be configured to move the cam with the biasing force provided by the biasing member by pushing against a surface of the spacer. In such embodiments, the spacer may be configured to push against the biasing member upon moving the cam against the biasing force provided by the biasing member. In use, the biasing member may be provided between the spacer and a surface of an associated supporting member such that the biasing member is compressed between the spacer and the supporting member when the cam moves from one axial position to the other against the biasing force.
The cam arrangement may comprise an additional spacer operable to act as an end stop to retain the cam in its first axial position. For example, the additional spacer may be configured to prevent the cam moving past its first axial position to a position where it projects less than the first distance from the supporting member. The additional spacer may be integrally formed with a portion of the cam arrangement.
The cam arrangement may comprise an additional spacer operable to act as an end stop to retain the cam in its second axial position. For example, the additional spacer may be configured to prevent the cam moving past its second axial position to a position where it projects more than the second distance from the supporting member. The additional spacer may be integrally formed with a portion of the cam arrangement.
In some embodiments the cam arrangement comprises a chamfered portion. The chamfered portion may be provided on the cam. In embodiments, the chamfered portion is provided on the cam and is configured, in use, to engage with a corresponding slot or aperture (e.g.) in a frame of the closure. The chamfered portion may be configured such that upon engagement of the chamfered portion with the aperture or slot, the cam is moved from its first axial position to its second axial position against the biasing force provided by the biasing member. In this way, the cam arrangement is configured to automatically move the cam between its axial positions against the biasing force upon, for example, closing or securing the closure.
In some embodiments the cam may be rotatable about an axis thereof. For example, the cam may be rotatable about a longitudinal axis. The cam may be rotatable about the axis along which the cam is moveable between first and second axial positions.
In some embodiments the cam is rotatable eccentrically about an axis which is offset from a central axis through the cam. Advantageously, rotating the cam eccentrically may allow for the position of the cam in a plane perpendicular to the axis of rotation to be adjusted, for example with respect to a supporting member to which it is mounted. This may be used to adjust a contact pressure between the closure and an associated frame, for example.
In some embodiments the cam may be rotatable when in its first axial position. In some embodiments the cam may be rotatable when in its second axial position. In embodiments, the cam may be rotatable when in its second axial position but its angular position may be fixed when in its first axial position.
In embodiments, the cam arrangement may comprise a retention mechanism which, when engaged, is configured to prevent rotation of the cam. The cam arrangement may be configured such that the retention mechanism is engaged when the cam is in its first axial position, and is disengaged when the cam is in its second axial position such that when the cam is in its second axial position it may be rotated between the plurality of angular positions.
According to a further aspect of the invention there is provided a lock mechanism for a closure, the lock mechanism comprising the cam arrangement of any preceding aspect of the invention mounted to a supporting member.
The cam arrangement may be mounted to the supporting member such that the biasing member is provided in an abutting relationship with a surface of the supporting member. In such embodiments, the cam arrangement may be mounted to the supporting member such that the biasing member is provided in an abutting relationship with a surface of the cam or a surface of a further component of the cam arrangement. In such embodiments, the lock mechanism may be configured such that the biasing member is compressed, in use, between the surface of the supporting member and the surface of the cam or the surface of the further component of the cam arrangement upon movement of the cam from one axial position to the other, e.g. from the first axial position to the second axial position.
In embodiments wherein the cam arrangement comprises a spacer, the cam arrangement may be mounted to the supporting member such that the biasing member is provided between the surface of the supporting member and a surface of the spacer. In such embodiments, the lock mechanism may be configured such that the biasing member is compressed, in use, between the surface of the supporting member and the surface of the spacer upon movement of the cam from one axial position to the other, e.g. from the first axial position to the second axial position.
The cam of the lock mechanism may be configured to engage with a corresponding slot or aperture in a frame of the closure for closing and/or securing the closure.
The supporting member may comprise a slot along which the cam arrangement may move during use of the lock mechanism. In use, movement of the cam arrangement along the slot in the supporting member may cause the cam to engage with a corresponding slot or aperture in a frame of the closure for securing the closure. Alternatively, the position of the cam arrangement with respect to the supporting member may be fixed during use of the lock mechanism. In such embodiments, the cam may be configured to engage with a corresponding slot or aperture in a frame of the closure upon closing a window/door sash of the closure, for example.
The lock mechanism may comprise an operating handle. In some embodiments the operating handle may be rotatable between two or more radial positions. In some embodiments the cam may be moveable along the slot of the supporting member under the operation of the operating handle.
In embodiments wherein the operating handle is rotatable between two or more radial positions, the cam may be moveable along the slot in the supporting member upon rotation of the operating handle. In such embodiments, the lock mechanism may comprise a gear arrangement configured to convert rotational movement of the operating handle to linear movement of the cam along the slot in the supporting member.
The lock mechanism may comprise a casement espagnolette type arrangement, for example, for providing a lock mechanism for a window. The lock mechanism may comprise a tilt and turn type arrangement, for example, for providing a lock mechanism for a window or door. The lock mechanism may comprise a parallel slide and tilt type arrangement, for example, for providing a lock mechanism for sliding doors such as patio doors. The lock mechanism may comprise a multipoint lock type arrangement, for example, for providing a lock mechanism for a window or door.
According to a further aspect of the invention there is provided a closure comprising the cam arrangement or the lock mechanism of any preceding aspect of the invention.
The closure may comprise a window or door sash. The closure may comprise a tilting, turning or sliding closure arrangement.
In embodiments the closure comprises a frame into which the window or door sash may be positioned. The frame may comprise an elongate slot therein for engagement of the cam of the lock mechanism. The elongate slot in the frame may be configured such that upon engagement of the cam with the elongate slot the cam is configured to be moved against the biasing force provided by the biasing member from its first axial position to its second axial position. In embodiments, the elongate slot in the frame may be configured such that upon disengagement of the cam with the elongate slot the cam is configured to be moved with the biasing force provided by the biasing member from its second axial position to its first axial position.
Within the scope of the claims it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1: is a side view of an embodiment of a cam arrangement and lock mechanism of the present invention;
Figure 2: is an end view of the cam arrangement and lock mechanism shown in Figure 1;
Figure 3: is a perspective view of the cam arrangement and lock mechanism shown in Figures 1 and 2;
Figure 4: is a series of end views of the cam arrangement and lock mechanism shown in the preceding Figures; and
Figures 5 - 7: are perspective views of an embodiment of a cam arrangement and lock mechanism of the invention.

An embodiment of the invention is illustrated in Figures 1 - 4. It relates to a cam arrangement 10 for a lock mechanism 12, for example for a closure such as a window or door. The cam arrangement 10 is configured to be mounted on a supporting member 16 of the lock mechanism 12 and comprises a cam 14. The cam 14 is moveable between two axial positions with or against a biasing force provided by a biasing member in the form of a wave washer 18. The invention extends to the lock mechanism 12 including the cam arrangement 10, and a closure 50 including the lock mechanism 12 and/or the cam arrangement 10.
In the illustrated embodiment, the cam 14 is moveable from a first axial position as shown in Figures 1-3, and a second axial position against a biasing force provided by the wave washer 18 (see Figure 4). Specifically, movement of the cam from its first axial position to its second axial position acts to compress the wave washer 18. Due to this compression, the washer 18 provides a biasing force acting to urge the cam 14 back to its first axial position. In order to remain in its second axial position the cam 14 must therefore be held against the biasing force, e.g. through engagement with a corresponding slot or aperture in a frame of the closure.
In its first axial position, the cam 14 projects a first distance from an upper surface 28 of the supporting member 16. Similarly, in its second axial position, the cam 14 projects a second distance from the upper surface 28 of the supporting member 16. Conventionally, cams may be provided at distances of 7.7mm or 9.0 mm measured from the surface of a supporting member 16. Accordingly, the illustrated embodiment comprises a cam arrangement 10 whereby the cam 14 is moveable between a first axial position at which the cam 14 projects approximately 7.7mm from the upper surface 28 of the supporting member 16, and a second axial position at which the cam 14 projects approximately 9.0mm from the upper surface 28 of the supporting member 16. As will be appreciated, other cam sizes are envisaged and within the scope of this application.
As shown, the cam arrangement 10 includes cam 14 having a cam shaft 20 and upper portion 22. The cam arrangement additionally includes a lower shaft 23, intermediate spacer 24 and lower spacer 26. The cam shaft 20 is operably connected to the lower shaft 23. The upper portion 22 and each of the spacers 24, 26 comprise a disc-shaped structure and are shown integrally formed at different points along the length of the cam shaft 20 or lower shaft 23.
The upper portion 22 provides a point of engagement for engaging with a corresponding slot or aperture, e.g. in a frame of the closure. In the illustrated embodiment, the upper portion 22 additionally includes a chamfered portion 17. In use, the chamfered portion 17 is configured to engage with a corresponding surface in a slot or aperture in a frame of the closure. The shape of the chamfered portion 17 is such that, upon engagement with the corresponding surface in the slot or aperture in the frame, the cam 14 may be urged against the biasing force provided by the biasing member 18, moving the cam 14 from its first axial position to its second axial position.
The intermediate spacer 24 is provided adjacent to the upper surface 28 of the supporting member 16 and is operable to act as an end stop to retain the cam 14 in its first axial position - e.g. to prevent the cam 14 moving past its first axial position to a position where it projects less than 7.7mm from the upper surface 28 of the supporting member 16.
The lower spacer 26 is provided between a lower surface 30 of the supporting member 16 and an end of the lower shaft 23. The lower spacer 26 provides a surface 32 against which the biasing member 18 may act, in use. As shown, the biasing member 18 is provided in an abutting relationship with the surface 32 of the lower spacer 26 and the lower surface 30 of the supporting member 16. In this way, the biasing member 18 may be compressed between the lower surface 30 of the supporting member 16 and the surface 32 of the lower spacer 26 on moving the cam 14 from its first axial position to its second axial position. This compression gives rise to the biasing force provided by the biasing member 18 to urge the cam 14 back to its first axial position.
In the illustrated embodiment, the supporting member 16 consists of an upper supporting arm 16a and a lower supporting arm 16b. Figures 1-3 show the cam arrangement 10 being operably mounted to the lower supporting arm 16b, and the cam arrangement 10' being operably mounted to the upper supporting arm 16a. As can be seen in Figure 3, the cam arrangement 10 is mounted to the lower supporting arm 16b in such a way that it projects through a slot 38 in the upper supporting arm 16a.
The upper supporting arm 16a and the lower supporting arm 16b are moveable with respect to one another. Specifically, the upper supporting arm 16a and lower supporting arm 16b may slide with respect to one another. This may be caused through operation of a gear arrangement 40 of the lock mechanism (as described with reference to Figures 5-7).
In use, movement of the supporting arms 16a, 16b with respect to one another results in relative movement of the cam 10 along the slot 38 in the upper supporting arm 16a. This may be as a result of movement of the cam 10 along the slot 38 which remains substantially stationary relative to the lock mechanism 12, or movement of the supporting arm 16a with respect to the cam 10 which remains substantially stationary relative to the lock mechanism 12. Further, movement of the supporting arms 16a, 16b with respect to one another causes relative movement of at least one of the cams 14, 14' with respect to a corresponding slot or aperture in a frame of the closure - e.g. to cause the cam 14, 14' to engage with the slot or aperture. This is shown in Figures 5 - 7 and described in detail below.
Cam arrangement 10' is configured in substantially the same way as cam arrangement 10. However, cam arrangement 10' is shown fixed in position with respect to the upper supporting arm 16a of the supporting member 16 and is not configured to move along a corresponding elongate slot in the lower supporting arm 16b of the supporting member 16, for example. However, and as described herein, in embodiments the cam arrangement 10' may move relative to other operational components of the lock mechanism 12 in order to engage with a corresponding slot or aperture in a frame of the closure.
Figure 5 shows cam arrangements 10, 10', 10", 10‴ of a lock mechanism 12 in position on a closure sash 50, which may be a door or window sash. Cam arrangements 10, 10" may be equivalent to cam arrangement 10 shown in the preceding Figures. Cam arrangements 10', 10‴ may be equivalent to cam arrangement 10' shown in the preceding Figures.
Figures 6 and 7 show the operational use of cam arrangement 10 and lock mechanism 12. The lock mechanism 12 shown in Figures 6 and 7 differs from lock mechanism 12 shown in the preceding Figures only in that the position of cam arrangements 10, 10' has been reversed. The operational use is substantially the same. Equivalent reference numerals have been used to aid understanding.
Specifically, Figures 6 and 7 show how the cam arrangement 10 of lock mechanism 12 may engage with a locking arrangement 100 which may, for example, be provided in a corresponding frame of the associated closure.
The locking arrangement 100 comprises a series of elongate slots 102, 104a, 104b, 104c, 104d which are configured, in use, to engage with cams 14, 14', etc. of the lock mechanism 12 to secure the closure. Specifically, and as shown, slot 102 is configured to engage with cam arrangement 10', and slot 104d is configured to engage with cam arrangement 10. Slots 104a, 104b and 104d may each be configured to engage with cam arrangements of further lock mechanisms, for example, on adjacent window or door sashes.
In Figure 6, the lock mechanism 12 is shown in a position prior to engagement with the locking arrangement 100. Specifically, cam arrangement 10' is shown proximal to the slot 102 of locking arrangement 100. Upon closing the associated closure - i.e. moving from Figure 6 to Figure 7, cam 14' of cam arrangement 10' is brought into contact with the slot 102, and in particular contact surface 103 of the slot 102. The contact surface 103 acts on the chamfered portion 17' of the cam 14' causing the cam 14' to move against the bias provided by biasing member 18' from its first axial position to its second axial position. In its closed position (Figure 7), the cam 14' is held in its second axial position against the bias provided by the biasing member 18' through contact with the contact surface 103 of the slot 102.
Following closing of the associated closure, cam 14 of cam arrangement 10 can be brought into engagement with slot 104d, for example, to secure the closure. As is described in detail below, this may be performed through use of an operating handle.
Specifically, lower supporting arm 16b may be moved relative to upper supporting arm 16a causing the cam 14 of cam arrangement 10 to move towards and subsequently into contact with the slot 104d. Slot 38 in the upper supporting arm 16a allows the cam arrangement 10 to move relative to the upper supporting arm 16a and engage with slot 104d whilst cam arrangement 10' remains stationary (i.e. engaged with slot 102) during movement of the lower supporting arm 16b.
Although not shown in the Figures, slot 104d may include a contact surface, in the same way as slot 102 includes contact surface 103, configured to urge the cam 14 against the biasing force provided by biasing member 18 from its first axial position to its second axial position upon engagement with the slot 104d.
In order to unlock and open the closure, the reverse process is followed. Specifically, lower supporting arm 16b is moved relative to upper supporting arm 16a, e.g. through rotation of an associated operating handle, causing the cam 14 of cam arrangement 10 to move away from and out of contact with the slot 104d. Subsequently, cam 14' of cam arrangement 10' is moved out of contact with the slot 102, and in particular contact surface 103 of the slot 102. This may be achieved through opening of the closure itself. By moving cam 14' out of contact with the contact surface 103, the contact surface no longer acts on the chamfered portion 17' of the cam 14' and as such, the cam 14' is free to move with the biasing force provided by biasing member 18' from its second axial position to its first axial position. Similarly, cam 14 of cam arrangement 10 is moved out of contact with its corresponding contact surface in slot 104d and thus moves with the biasing force provided by biasing member 18 from its second axial position to its first axial position.
As shown in Figures 6 and 7, the lock mechanism 12 additionally includes a gear arrangement 40. In use, the gear arrangement 40 is operable to act on the supporting arms 16a, 16b of the supporting member 16 to cause relative movement thereof. For example, rotation of one or more gears of the gear arrangement 40 causes linear movement of one or both of the supporting arms 16a, 16b of the supporting member 16.
The gear arrangement 40 includes an aperture 42 therein for receiving, for example, a spindle of an associated operating handle. In this way, acting on the operating handle - e.g. rotation of the operating handle - causes simultaneous rotation of one or more gears of the gear arrangement 40 causing linear movement of one or both of the supporting arms 16a, 16b of the supporting member. In the illustrated embodiment, rotation of the operating handle causes the lower supporting arm 16b to move linearly with respect to the upper supporting arm 16a, causing movement of the cam arrangement 10 towards or away from slot 104d along slot 38 in the upper supporting arm 16a.
Components of the cam arrangement 10 may be integrally formed, or may comprise separate components which are fixed together, e.g. by a fastening or fixing means. In embodiments, one or more components of the cam arrangement 10 may be riveted, for example via a spin riveting process. In embodiments, one or more components of the cam arrangement 10 may be fixed together using a retaining washer or a clip arrangement, for example.
Further, the biasing member 18 is shown in the illustrated embodiment as a compressible wave washer, which gives rise to the biasing force upon compression of the washer. However, it will be appreciated that other forms of biasing member may be used such as a resilient material, or a spring, for example. Further, the biasing member may comprise an extendable biasing member which gives rise to the biasing force upon extension or stretching of the biasing member.
Further, the above description relates to embodiments wherein the cam 14, 14' is required to be in its second axial position - e.g. in applications where a 9.0mm cam is required. However, the invention is equally applicable to applications where the cam 14, 14' is required to be in its first axial position - e.g. in applications where a 7.7mm cam is required. In such cases, upon engagement of the cam 14, 14' with its corresponding slot 102, 104d in the locking arrangement 100, the cam 14, 14' may not be moved against the biasing force provided by respective biasing member 18, 18'.
The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

A cam arrangement (10) for a lock mechanism (12) of a window or door closure, the cam arrangement (10) being configured to be mounted on a supporting member (16) of the lock mechanism (12), the supporting member (16) having an upper surface and a lower surface, the cam arrangement (10) comprising a cam (14) which is moveable between a first axial position at which the cam (14), when mounted to the supporting member (16) of the lock mechanism (12), projects a first distance from the upper surface of the supporting member (16) and a second axial position at which the cam (14), when mounted to the supporting member (16) of the lock mechanism (12), projects a second distance from the upper surface of the supporting member (16) - against a biasing force provided by a biasing member (18), the second distance being greater than the first distance wherein the cam arrangement (10) is configured such that, in use, the biasing member (18) is provided in an abutting relationship with the lower surface of the supporting member (16).
A cam arrangement (10) as claimed in claim 1, wherein the cam arrangement (10) is configured such that, in use, the biasing member (18) is provided in an abutting relationship with the lower surface of the supporting member (16) and a surface of the cam (14) or a surface of a further component of the cam arrangement (10).
A cam arrangement (10) as claimed in claim 2, wherein the cam arrangement (10) is configured such that, in use, the biasing member (18) is compressed between the surface of the supporting member (16) and the surface of the cam (14) or surface of the further component of the cam arrangement (10) upon movement of the cam (14) from the first axial position to the second axial position.
A cam arrangement as claimed in any one of the preceding claims, wherein the biasing member (18) comprises a spring.
A cam arrangement as claimed in any one of the preceding claims, wherein the biasing member (18) comprises a spring washer.
A cam arrangement as claimed in claim 5, wherein the spring washer comprises a wave washer.
A cam arrangement as claimed in any preceding claim, wherein the cam (14) comprises a chamfered portion (17) configured, in use, to engage with a corresponding slot or aperture in a frame of the closure to move the cam (14) from its first axial position to its second axial position against the biasing force provided by the biasing member (18).
A lock mechanism for a window or door closure, the lock mechanism comprising the cam arrangement (10) of any of claims 1 to 7.
A lock mechanism as claimed in claim 8, wherein the cam arrangement (10) is mounted to the supporting member (16) such that the biasing member (18) is provided in an abutting relationship with a surface of the supporting member (16) and a surface of the cam (14) or a surface of a further component of the cam arrangement (10).
A lock mechanism as claimed in claim 9 configured such that the biasing member (18) is compressed, in use, between the surface of the supporting member (16) and the surface of the cam (14) or surface of the further component of the cam arrangement (10) upon movement of the cam (14) from the first axial position to the second axial position.
A closure comprising the cam arrangement (10) of any of claims 1 to 7, or the lock mechanism of any of claims 8 to 10.
A closure as claimed in claim 11 comprising a window or door sash and a frame into which the window or door sash may be positioned.
A closure as claimed in claim 12 wherein the frame comprises an elongate slot therein for engagement with the cam (14) of the lock mechanism.
A closure as claimed in claim 13, wherein the elongate slot in the frame is configured such that upon engagement of the cam (14) with the elongate slot, the cam (14) is configured to be moved against the biasing force provided by the biasing member (18) from its first axial position to its second axial position.
A closure as claimed in claim 13 or claim 14, wherein the elongate slot in the frame is configured such that upon disengagement of the cam (14) with the elongate slot, the cam (14) is configured to be moved with the biasing force provided by the biasing member (18) from its second axial position to its first axial position.