GB2285276A - Sash window corner locking device - Google Patents

Abstract

In a closure such as a sash window, the sash 11 can be locked to the frame 10 by a locking mechanism in which a locking bar 16 projects from one edge of the sash frame into an aperture 23, on one frame member forming the corner, provided by a keeper 17. The keeper 17 is connected only to the other frame member forming the corner, through fixing holes 20, 22. In addition, slot 21 of the keeper and projection 28 lock the frame against relative movement parallel to the locking direction of the projecting bar 16. <IMAGE>

Description

CLOSURES The invention relates to closures such as sash windows.

In such a closure, there is a fixed frame and a sash connected to the frame by, for example, hinges or friction stays, for opening and closing movement out of and into the frame. In general, the frame and the sash will be rectangular with the frame including horizontal and vertical members which form a corner and which receive a correspondingly shaped corner formed by two sash members.

An example of such a closure is a sash window.

The sash can be locked to the frame by a locking mechanism carried by the sash and including a part which, in the locked position, projects from the sash at a position adjacent the corner and engages in an aperture provided in the vertical frame member. In this way, unauthorised opening of the sash by levering the sash out of the frame is resisted or prevented.

It is a problem, however, that manufacturing tolerances can produce a substantial gap between the sash and the frame when the sash is closed into the frame. In addition, when the frame is fitted into an aperture in a building, there will also be a gap between the vertical members of the frame and the aperture. These gaps can be of such a cumulative size that, by levering the frame and the sash apart, the frame and the sash can be separated by more than the distance by which the locking part of the locking mechanism extends into the vertical frame member, so that the locking part is disengaged.from the frame thus allowing the sash to be opened out of the frame.

According to a first aspect of the invention, there is provided a closure comprising a fixed frame and a sash connected to the frame for opening and closing movement out of and into the frame, the frame including horizontal and vertical members which form a corner and which receive a correspondingly shaped corner of the sash formed by horizontal and vertical sash members, the sash carrying a locking mechanism including a part which, in a locked position, projects from one sash member and is received in an aperture in the adjacent frame member, the other sash member and the adjacent frame member, at said corner, including respective parts which inter-engage when the sash is closed into the frame so that the sash is locked to the frame against relative movement in a direction parallel to said other sash and frame members.

By locking the sash to the frame, the effect of tolerances between the sash and the frame is avoided. Any force transmitted to the frame would also be transmitted to the sash and the two would move together.

According to a second aspect of the invention, there is provided a closure comprising a fixed frame and a sash connected to the frame for opening and closing movement out of and into the frame, the frame including horizontal and vertical members which form a corner and which receive a correspondingly shaped corner of the sash formed by horizontal and vertical sash members, the sash carrying a locking mechanism including a part which, in a locked position, projects from one sash member and is received in an aperture in the adjacent frame member, the frame including a keeper which provides said aperture and which is connected only to the other frame member forming said corner.

In this way, the aperture that receives a locking part will not move with the adjacent frame member should the frame and the sash be levered apart. This will therefore prevent the gap being enlarged to such an extent that the locking part is disengaged from the aperture.

In the closure of the second aspect of the invention, said other sash member and the associated horizontal frame member may, at the said corner, include respective parts which inter-engage when the sash is closed into the frame so that the sash is locked to the frame against relative movement in the direction parallel to said sash and frame members.

In this case, and in the first aspect of the invention, one part may comprise a projection extending into a space between said other sash member and the adjacent horizontal frame member, the other part comprising a slot provided in said space and extending normal to said member, the slot receiving said projection in the closed position of the sash.

The slot may be formed in a keeper connected to said adjacent other frame member with a projection being provided on the said other sash member.

The projection may be formed on a guide connected to said one sash member.

In said second aspect of the invention, the keeper may project into a space between the said first-mentioned sash member and the associated frame member, so that the entrance to said aperture is closely adjacent said sash member.

A single keeper may provide both the slot and the aperture, this keeper being generally L-shaped with the aperture being formed in one limb and the slot and the connection to the frame being in the other limb.

In this case, the position of the keeper may be adjustable relative to the other horizontal frame member so as to allow the inter-engaging parts to be aligned.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawing which is a schematic cross-section through a corner of a sash window.

The window comprises a frame 10 and a sash 11. The frame 10 and the sash 11 may be made from metal, wood or plastics or any other suitable material. The sash 11 is connected to the frame 10 by hinges or friction stays so that the sash 11 can move in and out of the frame 10 to close or open the sash 11.

The frame 10 includes a horizontal frame member 12 and a vertical frame member- 13 which meet to form a right angled corner. Similarly, the sash 11 includes a horizontal sash member 14 and a vertical sash member 15 which form a corresponding corner of the sash which is received in the frame corner when the sash 11 is closed into the frame 10, which is the position of the sash 11 shown in the drawing.

The sash 11 carries a locking bar 16 which extends through and parallel to the horizontal sash member 14 and, in the position shown in the drawing, projects from the vertical sash member 15 to engage the frame. Operation of an espagnolette mechanism (not shown) retracts the locking bar 16 to disengage it from the frame.

The frame 11 carries a generally L-shaped keeper 17. This may be of a zinc alloy or of any other metal of a strength to resist forced entry.

The keeper 17 has horizontal and vertical limbs 18,19 respectively. The horizontal limb is provided with a screw hole 20 which is elongate in the direction of the length of the horizontal limb 18. A screw (not shown) extends through this screw hole 20 to connect the keeper 17 to the horizontal frame member 12.

A generally rectangular section slot 21 is provided in the horizontal limb 18 of the keeper 17 adjacent the screw hole 20. The slot 21 extends normal to the length of the limb 18 and consequently normal to the lengths of the horizontal frame member 12 and the horizontal sash member 14. The purpose of this slot 21 will be described below.

The base of the slot 21 is provided with a second screw hole 22 through which extends a screw (not shown) to connect the keeper 17 to the horizontal frame member 12.

The vertical limb 19 of the keeper 17 bears against the vertical frame member 13 but is not connected to the vertical frame member 13. This vertical limb 19 includes an aperture 23 aligned with, and for receipt of, the end of the locking bar 16.

The vertical sash member 15 carries a guide 24. This guide 24 includes a body 25 of nylon material and a face plate 26 of stainless steel.

The body 25 is provided with two screw holes 27 by which the guide 24 is fixed to the vertical sash member 15. The body 25 also includes a projection 28 which fits round and extends from the horizontal sash member 14 at the corner.

As seen in the drawings, when the sash 11 is closed into the frame 10, this projection engages in the slot 21 and is a close fit in the slot 21. Exact alignment of the projection 28 and the slot 21 can be achieved by use of the elongate screw hole 20.

The face plate 26 extends over the body 25 and lies in the plane generally parallel to an outer surface 29 over the vertical limb 19 of the keeper 17.

Since the sash 11 moves relatively to the frame into and out of the closed position with an arcuate movement, the slot 21 and the projection 28, the end of the locking bar 16 and the entrance to the aperture 23 and the base plate 26 and the outer surface 29 of the vertical limb 19 are provided with lead-in chamfers to allow the sash 11 to be closed into the frame 10.

In use, the frame is installed in an aperture in a building, the aperture having a horizontal surface 30 on which rests the horizontal frame member 12 and a vertical surface 31. The vertical frame member 13 does not engage the vertical surface 31 - if it did it would not be possible readily to insert the frame 10 into the aperture. Rather, a gap is left between the vertical frame member 13 and the vertical surface 31. This gap may typically be 5 millimetres on each side of the frame, giving a total of 10 millimetres.

In addition, although-there is conventionally nominally a two millimetre gap between the sash 11 and the entrance to the aperture 23 in the frame 10, this gap may be as big as 4 millimetres due to manufacturing tolerances and the end of the locking bar 16 and the entrance to the aperture 23 may be provided with chamfers which effectively increase the gap by a further 2 millimetres.

Thus the total gap may be as great as 16 millimetres.

This cumulative gap can be substantially greater than the distance by which the locking bar 16 projects into the aperture 23. A typical maximum extension would be 9 millimetres and a typical minimum extension would be 6 millimetres. Thus, if the frame 10 and the sash 11 are levered apart they have the possibility of separating by more than the 6 to 9 millimetres necessary to disengage the locking bar 16 from the aperture 23. If this is done with all the locking bars in the espagnolette mechanism, the sash 11 can be opened out of the frame 10.

This is not possible with the arrangement described above with reference to the drawings. In this arrangement, the inter-engagement of the projection 28 and the slot 21 means that there is little or any gap between the sash 11 and the frame 10. Thus the sash 11 is effectively locked to the frame 10 so that any movement of the frame 10 will be transmitted to the sash 11.

In addition, since the vertical limb 19 of the keeper 17 is unconnected to the vertical frame member 13, any separation of the vertical frame member 13 and the vertical sash member 15 will not increase the separation between the outer surface 29 of the vertical limb 19 and the base plate 26.

In this way, forced entry by springing the locking bar 16 out of the aperture 23 is hindered or prevented.

There are, of course, many variations that could be made to the arrangement described above with reference to the drawings. Principally, the feature of the projection 28 and the slot 21 and the feature of the connection only of the horizontal limb 18 of the keeper to the frame 10 could be used separately. Both have individual advantages.

The projection 28 could be on the frame and the slot 21 in the sash. Alternatively, some other form of interengaging parts could be provided.

The locking mechanism may not be an espagnolette locking mechanism, it could be any other form of locking mechanism in which a locking member on the sash engages the frame adjacent a corner of the sash and frame. Of course, the sash and frame need not be rectangular or square, they could be any other shape in which a corner is provided.

The window described above is a side-hung window i.e. the connection between the sash and the frame is between vertical sash and frame members. However, the arrangement described above with reference to the drawing could be applied to a top-hung window in which the connection is between upper horizontal members of the sash and frame.

In this case, the locking bar 16 would project from the horizontal sash member 14 and engage the horizontal frame member 12. The keeper 17 would be attached to the vertical frame member 13 with the projection 28 extending from the vertical sash member 15.

The sash and frame need not be part of a window frame.

They could be part of a door or some other closure.

Claims (5)

1. A closure comprising a fixed frame and a sash connected to the frame for opening and closing movement out of and into the frame, the frame including two frame members out of and into the frame, the frame including two frame members which form a corner, the corner, when the sash is closed into the frame, receiving a correspondingly shaped corner of the sash formed by two sash edges, the sash carrying a locking mechanism including a part which, in a locked position and when the sash projects from one sash edge and is received in an aperture in that one of the two frame members which is adjacent the sash edge, the frame including a keeper which provides said aperture and which is connected only to the other frame member forming said corner.

2. A closure according to claim 1 wherein said other sash edge and the associated horizontal frame member include, towards said corner, respective parts which inter-engage when the sash is closed into the frame so that the sadh is locked to the frame against relative movement in the direction parallel t6 the length of said other sash edge and frame member.

3. A closure according to claim 1, wherein one part comprises a projection extending into a space between said other sash edge and the adjacent horizontal frame member, the other part comprising a slot provided in said space and extending normal to the length of said member, the slot receiving said projection in the closed position of the sash.

4. A closure according to claim 1, wherein the keeper projects into a space between the said first-mentioned sash member and the associated frame member, so that the entrance to said aperture is closely adjacent said sash member.

5. A closure substantially as hereinbefore described with reference to the accompanying drawing.