GB2217775A - Window catch - Google Patents

Abstract

A "child-proof" window catch comprises an arm 1 pivotally mounted on a window cooperating with a keeper 2 secured to the window sill. The arm has an elongated recess and the keeper comprises a loop having a gap in it. The arm can be disengaged from the loop in only one relative position at which it can bs forced out of the loop, through the gap, at a region 8A. Projections 9 provide a resistance to closing when the window is fully open. <IMAGE>

Description

Window Catches This invention relates to window catches which permit only restricted opening of windows to which they are fitted until deliberately manipulated to a disengaged condition in which unrestricted opening of the windows is permitted.

The primary function of such a catch is to permit a window to be partially opened to secure a degree of ventilation but to deter unlimited opening by a small child.

A catch in accordance with a feature of the invention comprises an arm for pivotally mounting on, say, a window and a keeper for mounting fixedly on, say, a fixed frame member such as a window sill, wherein the arm is formed with an elongate recess bounded by a wall which is continuous but has a localized region of reduced height, and the keeper is in the form of a loop having a gap in it, the parts being engageable by pressing the said region through the gap so that the keeper engages in the recess, in which it is positively retained except when in registry with the said gap, for relative movement longitudinally of the arm.

One form of window catch in accordance with the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a diagrammatic perspective view of the catch; Figs. 2 and 3 are diagrammatic plan views of the catch showing the window closed and slightly open, respectively; Fig. 4 is a plan view of the arm; Figs. 4A and 4B are sections on the lines AA and BB of Fig. 4; and Fig. 5 is a side view of the keeper.

Referring first to Figs. 1 to 3, the catch is shown with its arm 1 pivotally mounted on a window W and its keeper 2 secured to a window sill S or other fixed frame member.

The arm 1 is mounted by means of a bracket 3 and pivot 4 which allows the arm to pivot about an axis which, in this case, is vertical and parallel with the window hinge (not shown). The arm is shown in these figures engaged with the keeper Z. The parts are shown in Figs. 1 and 2 with the window fully closed and in Fig.

3 with the window open to the maximum extent permitted by the catch.

The arm 1 is shown in more detail in Figs. 4, 4A and 4B. It is preferably moulded from a relatively rigid plastics material such as nylon. It has at one end a hole 6 to receive the pivot 4 by which it is fastened to the bracket 3 and over most of its length it has a "dumb-bell" section as best seen in Figs. 4A and 4B, with a continuous web 7 and a boundary wall 8. In a localized region 8A near the said one end the height of the wall 8 is reduced and the residual material in this region is tapered outwardly to a wedge shape. The web 7 and wall 8 thus define an elongate recess to either side of the web.

Adjacent the free end of the arm, the wall 8 has internal projections 9 which form a local restriction in the width of the recess, adjacent its end.

The keeper 2, as shown in Fig. 5, takes the form of a hook or loop having a narrow gap 11 in a vertical region thereof. The loop is mainly of circular cross section and is slightly reduced in cross section to form two opposed tips 12 adjacent the gap. The keeper is also moulded from a substantially rigid but resilient plastics material, such as nylon, so that it can be of robust construction but with sufficient resilience to permit the tips 12 to be forced apart to increase the gap 11 by a small amount.

In use, assuming the window to be fully open and the arm to extend parallel with the window, i.e. in the relative position shown in Figs. 1 and 2, closure of the window will effect automatic, snap-fitting engagement of the catch, since the region 8A of the arm is in registry with the gap 11 in the keeper. The tips 12 therefore ride over the wedge shaped region 8A to enter the recesses to either side of the web 7. Thereafter, when the window is opened, the tips 12 ride along the arm until they reach the end of the recess at the free end of the arm, whereupon no further opening movement of the window is possible. In the last stage of this opening movement, the tips 12 snap past the projections 9 so as to provide a resistance to closing movement of the window, for example due to the action of air currents.

However, the window can be closed by applying sufficient force to overcome that resistance. The window can be partially opened and re-closed any number of times without the arm and keeper becoming disengaged.

However, if it is desired to disable the catch, the window is simply pushed open whilst the arm is held parallel with the window to go with it. The tips 11 of the keeper are thus caused to spring apart and pass through the region 8A. The arm is restrained to stay in this parallel position, for example by engagement of the pip 13 shown in Fig. 4 with a mating recess (not shown) in the bracket 3. Thus, when the window is next fully closed the arm will again be engaged by forcing the region 8A through the gap between the tips 12.

Many variations and modifications will of course be possible within the scope of the present invention.

For example, the web 7 in the arm is not essential, but it has the advantages of strengthening the arm and of maintaining the arm in its correct plane, since the web is engaged from above and below by the tips 12 of the keeper.

It will also be apparent that the pivoted arm could be mounted on a fixed frame member, such as the window sill, and the keeper on the window. Also, a positive locking device could be provided, if desired to lock the window in its closed or its limited open position.

Claims (5)

CLAIMS:

1. A window catch comprising an arm for pivotally mounting on, say, a window and a keeper for mounting fixedly on, say, a fixed frame member such as a window sill, wherein the arm is formed with an elongate recess bounded by a wall which is continuous but has a localized region of reduced height, and the keeper is in the form of a loop having a gap in it, the parts being engageable by pressing the said region through the gap so that the keeper engages in the recess, in which it is positively retained except when in registry with the said gap, for relative movement longitudinally of the arm.

2. A catch according to claim 1, wherein the said arm has a continuous web within the said wall and engaged from opposite sides by opposed tips defining the gap in the keeper.

3. A catch according to claim 1 or 2 wherein the elongate recess extends from one end of the arm at which the arm is pivotally supported to an opposite, free end, the said region being adjacent the pivoted end.

4. A catch according to claim 3, in which the recess is formed, adjacent the free end of the arm, with projection means which co-operate with the keeper and restrain the arm against return movement relative to the keeper.

5. A window catch substantially as herein described with reference to the accompanying drawings.