Window fastener

Abstract

A window fastener is disclosed comprising a base adapted for mounting to a window frame, a handle mounted to the base and configured to rotate relative thereto, and a friction member positioned between the base and the handle. The friction member is compressible such that, upon assembly, it applies a frictional resistance to relative rotation between the handle and the base. The frictional resistance serves to maintain the handle in a selected angular position and to prevent unintended movement during use. The arrangement provides controlled rotational resistance while allowing intentional adjustment of the handle by a user, thereby improving operational stability and user control of the window fastener.

Description

BACKGROUNDWindow fasteners have a handle which can be operated to allow a window to be opened and closed. A tongue on the handle engages a window frame to hold the window sash in place. When the handle is operated, the handle rotates so that the tongue no longer engages the window frame. The window sash can then be pushed to open the window.However, there are cases in which existing window fasteners are not entirely suitable.SUMMARYIn an example embodiment, there is provided a window fastener, comprising: a base; a handle configured to rotate relative to the base; and a friction member; wherein the friction member is configured to resist rotation of the handle relative to the base.BRIEF DESCRIPTION OF DRAWINGSThe invention will be described by way of example with reference to the drawings, which show various preferred embodiments of the invention. However, these are provided for illustration only, and the invention is not limited to the particular details of the drawings and the corresponding description.Figure 1   is a front perspective view of a fastener.Figure 2   is a back-perspective view of the fastener of Figure 1.Figure 3   is an exploded view of the fastener in Figure 1.Figure 4   is a back-perspective view of a handle.Figure 5   is a front perspective view of a first friction member.Figure 6   is a front perspective view of a base.Figure 7 is a back-perspective view of the base of Figure 6.Figure 8 is a perspective view of a second friction member.DETAILED DESCRIPTIONIn some embodiments, a window fastener has at least one friction member which resists rotation of the handle relative to the base. The friction member may be adjusted for a particular level of friction. The friction can be enough to resist rotation of the handle relative to the base caused by the weight of the handle. This may mean that the friction member resists a torque of between about 2.5 Nm and about 5 Nm.More generally, window fasteners may be used to latch a window in a closed position. One or more handle-operated window fasteners are mounted on the window sash. This may be a wedged fastener having a pivotally movable handle with a tongue to engage a wedge element. The fastener will generally be fastened to the window sash and the wedge to the window frame.The window fastener may include two spaced-apart tongues. One may be a latching tongue for fastening the window in a closed position and the other may be a venting tongue to fasten the window in a venting position. These fasteners provide a level of security against unauthorised entry through the window while also allowing the window to be partially open to provide air flow into the building. A further form of window fastener is the wedgeless fastener. This uses a movable flap to overlap the edge of the window frame when the sash is in the closed position. In many such fasteners, if the handle is not rotated sufficiently to allow the flap to rotate fully horizontal, the lower, inner end of the flap can fail to clear the upper, outer edge of the bottom side of the frame as the sash is pulled closed, and can strike against the frame. This may potentially damage the frame, the sash and the fastener.In some cases, the window may be unintentionally closed. For example, if there is a gust of wind, the window sash is forced towards the frame. This may cause damage to components. In particular, if the handle is rotated so that the tongue is aligned with the window frame, the tongue may hit against the outside of the frame.To reduce the risk of this, at least one friction element may be included to resist the rotation of the handle relative to the base. This can prevent the handle rotating when the window is open. Thus if window is closed suddenly, the handle can stay in position such that a tongue is not aligned with the window frame.Figures 1 to 3 show an example of a window fastener according to an embodiment.The window fastener has a base 100 which can be secured to a window sash. An example base 100 is shown in Figures 6 and 7. The window fastener can be mounted to the window sash by using one or more fasteners (such as screws) through holes 102 in the base 100. The heads of the fasteners sit in recesses 112 and pull against the recesses 112 to mount the base 100 to the window sash. The base 100 has a central aperture 104 formed between the holes 102.A handle 200 provides a lever for a user to operate the window fastener. An example handle is shown in Figure 4. One end of the handle 200 has a boss 202 which can be used to couple the handle 200 with the base 100. The boss 202 has a fastener aperture 208 for a fastener 600 (such as a screw) to be engaged.In operation, a user can grip handpiece 206 to rotate the handle 200 relative to the base 100 and consequently relative to the window sash. The handle 200 rotated about the fastener 600 between a closed position and an open position. The angular movement between the closed position and the open position may be about 90°, such that the open position has the handpiece 206 pointing vertically upwards and the closed position has the handpiece 206 pointing horizontally. In the closed position, the latching tongue 210 is aligned with the window frame. When the window sash is engaged in the window frame, the latching tongue 210 pulls against the window frame to secure the window sash in place. In the open position, the latching tongue 210 is out of alignment with the window frame, and so the window sash can be opened. The latching tongue 210 may have a latching wear surface to avoid damage to the window frame when the latching tongue 210 pulls against the window frame.The handle 200 may further have a venting tongue 212. This operates similar to the latching tongue 210, except that the latching tongue 210 retains the window sash slightly open and apart from the window frame. The venting tongue 212 may have a venting button to avoid damage to the window frame when the venting tongue 212 pulls against the window frame.A cover 300 may be used to cover the holes 102. The cover 300 is shaped to not obscure the central aperture 104 or the handle 200.A first friction member 400 is located between the base 100 and the handle 200, and may function as a washer. An example first friction member 400 is shown in Figure 5. A central aperture 402 of the first friction member 400 receives the boss 202 of the handle 200. The boss 202 of the handle 200 and the central aperture 402 of the first friction member 400 mesh. That is, formations 204 around the outside of the boss 202 may interdigitate with formations 404 around the inside of the central aperture 402. This couples the handle 200 and the first friction member 400 such that if the handle 200 rotates (such as during operation of the handle 200), the first friction member 400 rotates in concert with the handle 200.The first friction member 400 can also engage with the central aperture 104 of the base 100. Formations 406 around the outside of the central aperture 402 engage with formations 106 around handle-adjacent portion of the inside of the central aperture 104 of the base 100. The formations 106 define the extent of rotation of the first friction member 400. That is, the first friction member 400 (and consequently the handle 200) can rotate in either direction until the formations 406 abut respective formations 106. The amount of angular rotation of the first friction member 400 between formations 106 corresponds to the angular movement of the handle 200, and so may be about 90°.The path between two formations 406 and / or two formations 106 may be ramped. As the handle 200 rotates, the handle 200 moves inwards and outwards relative to the base 100.The first friction member 400 may include a latching wear surface 408 which couples to the latching tongue 210.A second friction member 500 is located between the base 100 and the head 602 of the fastener 600, and may function as a washer. An example second friction member 500 is shown in Figure 8. A central aperture 502 of the second friction member 500 receives the boss 202 of the handle 200. The boss 202 of the handle 200 and the central aperture 502 of the second friction member 500 mesh. That is, formations 204 around the outside of the boss may interdigitate with formations 504 around the inside of the central aperture 502. This couples the second friction member500and the handle 200 such that if the handle 200 rotates (such as during operation of the handle 200), the second friction member 500 rotates in concert with the handle 200 and the first friction member 400.The second friction member 500 can also mate with the central aperture 104 of the base 100. Formations 506 around the outside of the central aperture 502 engage with formations 108 around the sash-adjacent portion of the inside of the central aperture 104 of the base 100. The formations 108 define the extent of rotation of the second friction member 500. That is, the second friction member 500 (and consequently the handle 200) can rotate in either direction until the formations 506 abut respective formations 108. The amount of angular rotation of the second friction member 500 between formations 108 corresponds to the angular movement of the handle 200, and so may be about 90°.The path between two formations 506 and / or two formations 106 may be ramped. As the handle 200 rotates, the handle 200 moves inwards and outwards relative to the base 100.The second friction member 500 may sit in a recess 110 in the sash-adjacent face of the base 100. This allows the second friction member 500 to sit flush with or slightly below the sash-adjacent face of the base 100, and thus for the base 100 to be mounted flush onto a window sash.A recess is formed in the sash-adjacent face of the base 100. The recess can accommodate the head 602 of the fastener 600 so that the head 602 of the fastener 600 sits flush with the sash-adjacent face of the base 100. This in turn allows the base 100 to be mounted flush to the window sash.OperationWhen assembled, the fastener 600 passes through the central aperture 502 of the second friction member 500, the central aperture 104 of the base 100, and the central aperture 402 of the first friction member 400. The fastener 600 is then received and retained in the fastener aperture 208 of the handle 200. Tightening the fastener 600 causes the first friction member 400 and the second friction member 500 to be compressed between the handle 200 and the base 100, and between the base 100 and the head 602 of the fastener 600 respectively.The first friction member 400 and second friction member 500 are formed, at least in part, of a material which is partly deformable under pressure. This may be a plastic material. In some embodiments, the plastic material is one of a thermoplastic elastomer, nylon, or acetal.When the first friction member 400 is under pressure (for example, from the fastener 600 being engaged in the fastener aperture 208), the first friction member 400 may be forced to push against the inner wall of the central aperture 104 of the base 100. This restriction in the outwards expansion of the first friction member 400 under compression generates a friction force which resists rotation of the first friction member 400 (and therefore the handle 200) relative to the base 100.Likewise, when the second friction member 500 is under pressure, the second friction member 500 may be forced to push against the inner wall of the central aperture 104 of the base 100 and / or the recess 110. This restriction in the outwards expansion of the second friction member 500 under compression generates a friction force which resists rotation of the second friction member 500 (and therefore the handle 200) relative to the base 100.The friction force generated by each of the first friction member 400 and the second friction member 500 may be configured by varying the deformability of the material used for the respective friction member and / or the dimensions of the friction member. For example, a greater depth of the friction member (relative to the height of the formations 106, 108) increases the compression of the friction member when the window fastener is assembled. Increased compression tends to lead to an increased friction force.The total friction force generated by the first friction member 400 and the second friction member 500 may be sufficient to hold the handle 200 in place. When the handle 200 is in an angled position (that is, with the handpiece 206 not perfectly vertical), it will tend to naturally fall downwards due to the effect of gravity. The friction members may be configured such that the friction force is greater than the force of gravity on the handle 200. The friction members may therefore be configured such that a torque of at least about 2.5 Nm applied to the handle 200 is required to overcome the friction force. This holds the handle 200 in place until a user operates the handle 200.At the same time, the friction force may be sufficiently low that a user can easily operate the window fastener. If the friction force is too great, some users may find it difficult to rotate the handle 200. The friction members may be configured such that a torque of less than about 5 Nm applied to the handle 200 is required to overcome the friction force.By configuring the first friction member 400 and the second friction member 500 to provide a friction force in this range, the handle 200 tends to reliably remain in place without compromising the usability of the window fastener.Moreover, because the friction force is generated by the compression of the first friction member 400 and the second friction member 500, the friction force tends to be retained over an extended use of the window fastener. That is, as long as the friction members are held under compression, a friction force is generated. This may lead to a reliable window fastener.InterpretationThe window fastener has been described as having a first friction member 400 and a second friction member 500, each of which contributes to the total friction force. However, in some cases one of the friction members may be omitted. For example, the first friction member 400 may alone provide a sufficient friction force to resist rotation of the handle relative to the base caused by the weight of the handle.While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, this should not be taken to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the general inventive concept.It is acknowledged that the terms "comprise", "comprises", and "comprising" may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, these terms are intended to have an inclusive meaning - that is, they will be taken to mean an inclusion of the listed components which the use directly references, and possibly also of other non-specified components or elements.

Claims

CLAIMS1.   A window fastener, comprising:a base;a handle configured to rotate relative to the base; anda friction member;wherein the friction member is configured to resist rotation of the handle relative to the base.

2. The window fastener of claim 1, wherein the friction member is configured to resist rotation of the handle relative to the base caused by the weight of the handle.

3. The window fastener of claim 1 or 2, wherein the friction member is configured to resist a torque of at least about 2.5 Nm and / or to resist a torque of less than about 5 Nm.

4. The window fastener of any of claims 1 to 3, wherein the friction member is a washer.

5. The window fastener of any of claims 1 to 4, wherein the friction member is configured to be compressed between the base and the handle.

6. The window fastener of any of claims 1 to 5, wherein the friction member comprises a recess configured to receive a boss of the handle.

7. The window fastener of any of claims 1 to 6, wherein the friction member is mounted to the handle.

8. The window fastener of any of claims 1 to 6, wherein the base comprises a recess configured to receive the friction member.

9. The window fastener of any of claims 1 to 8, wherein the friction member is located in a recess, the recess being configured to restrict expansion of the friction member.

10. The window fastener of claim 9, wherein the restriction of the recess causes the friction member to press against the base to resist rotation of the handle relative to the base.

11. The window fastener of any of claims 1 to 10, wherein the friction member comprises one or more formations configured to engage with corresponding surfaces of the base.

12. The window fastener of any of claims 1 to 11, wherein the friction member is made of a plastic material.

13. The window fastener of claim 12, wherein the plastic material is one of a thermoplastic elastomer, nylon, and acetal.

14. The window fastener of any of claims 1 to 13, further comprising a second friction member, wherein the second friction member is configured to resist rotation of the handle relative to the base.

15. The window fastener of claim 14, wherein the second friction member is configured to be compressed between the base and a head of the window fastener.

16. The window fastener of claim 14 or 15, wherein the second friction member has a first recess configured to receive a boss of the handle and a second recess configured to receive the head of a screw17. The window fastener of any of claims 1 to 16, wherein the base is configured to be mounted to a window sash.

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