GB2196050A - Fastener for securing frames together - Google Patents

Abstract

The fastener for securing a movable frame (e.g. a window sash 10, cupboard/safe door) to an adjacent stationery frame (e.g. window casement 11) comprises a base 14 mounted on or integral with one frame 10, a handle 13 mounted on base 14 by pivot 15 to pivot in a plane parallel to the plane of base 14 and having a transverse spur 131 for selectively engaging (a pressure pad 12 of) the other frame 11 and a brace 132, 141 spaced from pivot 15 for bracing the handle 13 against the base 14 to resist forces acting on the spur 131 perpendicular to base 14. Brace 132, 141 comprises a tongue 132 connected to handle 13 directly beneath spur 131 and slidable under bridge 141 of base 14-although it need not be beneath. Materials of the various components are specified. <IMAGE>

Description

SPECIFICATION Fastener for securing frames together This invention relates to fasteners. for securing a movable frame such as a window sash to an adjacent stationary frame such as a window casement, and is particularly useful when applied to fasteners of the so-called cockspur type.

Conventional cockspur window fasteners comprise a flat base for attachment to a window sash, and a handle whose end is pivoted to the base. The handle has a transverse spur for selectively engaging a wedge-like pressure pad fixed to the adjacent stationary window casement. When the handle is turned towards the casement, the spur rides up over the pressure pad, drawing the sash firmly into its closed position against the casement.

Such cockspur fasteners require comparatively heavy duty pivots between the handle and the base since the pivot is required to resist bending moments arising from reaction forces acting on the spur perpendicular to the handle and the base, for example when the window is being fastened or forced when fastened. Handles with such heavy-duty pivots tend to have substantial dimensions in the plane of the sash, and this detracts from the appearance of the fastener. Accordingly, it is an object of the invention to obviate the need for such a heavy-duty pivot while maintaining, or improving, the strength of the fastener.

The invention provides a fastener for securing a movable frame such as a window sash to an adjacent stationary frame, comprising a base for connection to one of the frames, and an elongate handle mounted on the base to pivot in a plane generally parallel to the plane of the base, the handle having a transverse spur extending in the said pivotal plane for selectively engaging the other frame in accordance with the pivotal position of the handle selectively to prevent or to allow relative movement of the frames perpendicularly to the pivotal plane, and means, spaced from the handle pivot point, for selectively bracing the handle against the base such as to resist reaction forces acting on the spur perpendicularly to the said pivotal plane tending to separate the handle from the base.

The extra strength provided by bracing the handle against the base, in the position at which the frames are secured in use, allows the pivot to be less resistant to the bending moments arising from the said perpendicular forces, and consequently to be of a more compact size than in conventional cockspur fasteners where the pivot is load-bearing.

Preferably, the bracing means and the spur are at substantially the same longitudinal distance from the handle pivot point. The spur is preferably at an intermediate point along the length of the handle, the pivot point preferably being at one end of the handle.

In its preferred form, the portion of the handle between the pivot point and the bracing means lies closely adjacent the base, and the remaining, free end portion of the handle is spaced from the plane of the base to allow it to be gripped when the base is attached to the frame.

The bracing means preferably comprises two releasably interengageable formations carried by the base and the handle, which interengage at a pivotal position of the handle which is such as to cause the spur, in use, to engage the said other frame. The formations preferably comprise a tongue slidable into and out of a bridge formation. preferably, the said tongue is carried by the handle, and the bridge formation is carried by the base. In a preferred form of the invention, the bridge formation is integral with the base, and the tongue is integral with the handle.

The invention also provides a window comprising a fastener in accordance with the invention as described above, the base being connected to the sash, and the spur being adapted to engage an edge portion of the casement, the sash and casement constituting the said movable and stationary frames respectively.

In order that the invention may be better understood, a preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front elevation of a window fastener embodying the invention, shown in situ but omitting the associated window sash and casement; Figure 2 is a right hand side elevation of the window fastener of Figure 1; and Figure 3 is a section taken at Ill-Ill of the window fastener of Figure 1, but including associated elements of the window sash and casement.

A window fastener for securing a window sash 10 (Figure 3) to an adjacent window casement 11 comprises a handle 13 pivotally mounted at one end by a pivot 15 to a base 14. The base 14 is in the form of an elongate plate lying essentially in a plane parallel to the plane in which the handle 13 pivots. However, the base 14 has a centrally- disposed bridge 141 against which a correspondingly centrallydisposed portion of the handle 13 may be braced in use, as described in greater detail below.

The window fastener is of the so-called cockspur type, in that it has a transverse spur 131 at an intermediate point along the length of the handle 13, generally in the plane of the pivotal movement of the handle 13. In the closed position of the window fastener, as illustrated in the drawings, the spur 131 engages a wedge-like pressure pad 12 bolted to the stationary window casement 11. This pre vents the window sash 10 from swinging open, i.e. from moving in the downwards di rection of Figure 3, and tightly secures the window sash 10 against the projecting edge of the window casement 11. In order to re lease the window fastener, the handle 13 is pivoted about its pivot 15, anti-clockwise in Figure 1, until the spur 131 no longer projects over the pressure pad 12.

In order to guide the spur 131 smoothly over the pressure pad 12 during closing action, the free end edge of the spur 131 is tapered, as shown in Figure 3. Alternatively, the pressure pad 12 could be provided with a taper as viewed in section in Figure 3.

The handle 13 comprises an upper portion 136 whose undersurface lies closely adjacent the base 14, a handle grip portion 138 spaced from the plane of the base to allow it to be gripped when the base is attached to the window sash 10, and an intermediate portion 137 inclined outwardly of the base 14.

The handle 13 has an open shell structure, and comprises an elongate front face 135 and a side flange 134.

The intermediate bracing of the handle against the base is effected by the sliding interengagement of a tongue 132 connected at its base 133 to the handle 13 at the same longitudinal distance from the handle pivot point 15 as the spur 131. In this example, the tongue 132 lies directly beneath the spur 131 and is of a similar width (in the longitudinal direction of the handle 13). The tongue 132 depends from the side flange 134 of the handle 13 in a direction towards the pressure pad 12 in use, in a plane parallel to and intermediate the planes of the spur 131 and base 14. However, the tongue 132 is shorter than the spur 131 (in a direction transverse to the handle 13) so as to avoid interference with the window casement 11 and the pressure pad 12 in use.As shown in Figure 3, the tongue 132 is provided with a tapered free end edge so as to guide the tongue smoothly under the bridge 141 of the baste 14 to effect the bracing action.

On closing the window fastener, the handle 13 pivots in the clockwise direction of Figure 1 and the tongue 132 slides under the bridge 141 at the same time as the spur 131 slides over the pressure pad 12. Forces perpendicular to the base 14 acting on the spur 131, tending to open the window, are resisted almost solely by the brace constituted by the tongue 132 and the bridge 141. Without the brace, these forces, acting at the spur 131, would give rise to a bending moment about the pivot 15: The existence of the brace avoids the need for the pivot 15 to resist such bending moments. Accordingly, the pivot 15 is of lower duty than the corresponding pivot in conventional cockspur window fasteners.

The handle 13 is die-cast of a zinc alloy, and the base 14 is of extruded aluminium or die-cast alloy, the pivot 15 comprising an integral rivet in the handle 13. The pressure pad 12 in this example is of injection-moulded plastics material. The arrangement shown in the drawings is applicable to aluminium windows. When applied to typical UPVC windows, in which the casement 11 is generally thicker, the pressure pad 12 is generally substantially thinner (in the vertical dimension of Figure 3) than that illustrated in Figure 3.

By providing the brace 132, 141 which takes the major part of the load in the fastening and securing of the window, as indicated above, the non-load bearing pivot 15 may be of substantially smaller dimensions in the plane of the window frames. This has the advantage of avoiding any projection of the window fastener, in its closed position, over the glass line of the sash, but without sacrificing any of the grip clearance, i.e. the distance between the grip portion 138 and the sash 10.

Although in the example described with reference to the drawings the brace is provided immediately beneath the spur, this is not essential, but the effectiveness of the brace in bearing the load of the fastener is greater the nearer the brace is to the spur. Further, although in the example described the base is constituted by a plate to be secured to the sash, the base could instead be connected integrally with the sash, the bridge being replaced by an appropriate formation projecting from the sash. Further still, although the handle has been described as being carried by the sash, it could instead be carried by the casement, with an appropriate surface on the sash for engagement by the spur.

The invention is applicable to the fastening of any movable frame to an adjacent stationary frame, for example the door of a cupboard or safe.

Conventional cockspur window fasteners may be locked by means of a bolt extending perpendicularly through a threaded bore in the spur, such that on screwing the bolt so that it projects inwardly of the fastener beneath the undersurface of the spur, it abuts against a lug (not shown) on the base plate. The selective engagement of the bolt with the lug then prevents pivotal movement of the handle. A similar arrangement could be provided with the window fastener embodying the present invention, the bolt or a similar locking device being located either at the spur or at another position in the upper portion 136 of the handle 13.

Claims (13)

1. A fastener for securing a movable frame such as a window sash to an adjacent stationary frame, comprising a base for connection to one of the frames, and an elongate handle mounted on the base to pivot in a plane generally parallel to the plane of the base, the handle having a transverse spur extending in the said pivotal plane for selectively engaging the other frame in accordance with the pivotal position of the handle selectively to prevent or to allow relative movement of the frames perpendicularly to the pivotal plane, and means, spaced from the handle pivot point, for selectively bracing the handle against the base so as to resist reaction forces acting on the spur perpendicularly to the said pivotal plane tending to separate the handle from the base.

2. A fastener according to Claim 1, wherein the bracing means and the spur are at substantially the same longitudinal distance from the handle pivot point.

3. A fastener according to Claim 1 or Claim 2, wherein the spur is at an intermediate point along the length of the handle, the pivot point being at one end of the handle.

4. A fastener according to any preceding claim, wherein a portion of the handle between the pivot point and the bracing means lies closely adjacent the base, the remaining, free end portion of the handle being spaced from the plane of the base to allow it to be gripped when the base is connected to the said one frame.

5. A fastener according to any preceding claim, wherein the bracing means comprises two releasably interengageable formations carried by the base and the handle, which interengage at a pivotal position of the handle which is such as to cause the spur, in use, to engage the said other frame.

6. A fastener according to Claim 5, wherein the said formations comprise a tongue slidable into and out of a bridge formation.

7. A fastener according to Claim 6, wherein the tongue forms part of the handle, and the bridge formation forms part of the base.

8. A fastener according to Claim 7, wherein the bridge formation is integral with the base.

9. A fastener according to Claim 7 or 8, wherein the tongue is integral with the handle.

10. A fastener according to Claim 6, 7, 8 or 9, wherein the tongue is wedge-shaped to guide the handle towards the base as the tongue engages the bridge formation.

11. A window comprising a sash and a casement, and a fastener according to any preceding claim connected to the sash such that the spur selectively engages an edge of the casement to fasten the window.

12. A fastener substantially as described herein with reference to the accompanying drawings.

13. A window provided with a fastener, substantially as described herein with reference to the accompanying drawings.