GB2276202A

GB2276202A - Friction stay incorporating locking head

Info

Publication number: GB2276202A
Application number: GB9405454A
Authority: GB
Inventors: Ronald Percival Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-19
Filing date: 1994-03-21
Publication date: 1994-09-21
Anticipated expiration: 2014-03-21
Also published as: GB2276202B; GB9405454D0

Abstract

A friction window stay incorporates a locking head (13) to lock the head of the stay against forced opening. A protrusion (13) on the end of the sash mounting member (6) of the stay provides a contact face (13b) which is oriented to engage substantially squarely in the direction of possible forced opening of the sash against a barrier (14c) on the frame mounting member (3) of the stay when the stay is closed. Preferably the barrier on the frame mounting member comprises a metal edge extending generally at right angles to the frame mounting member of the window stay. The protrusion may be made of plastics material or of a metal which is softer than that of the barrier. <IMAGE>

Description

A LOCKING HEAD FOR A WINDOW STAY FIELD OF INVENTION My present invention comprises a locking head for a window stay.

BACKGROUND The four bar friction window stay (see New Zealand patent No. 144922/146130/146886) has been sold in many countries in its basic and subsequently refined forms.

With friction window stays it is possible for the head of the window to be forced open from outside the window frame, by levering between the peripheral sealing flange at the head of the window and the window frame with a crowbar for example. A window stay can incorporate a locking head to counter this danger, but many known forms of locking head. are not as strong as is desirable and still allow the window to be levered open if more force ie used.

SUMMARY OF INVENTION My present invention provides an improved or at least alternative form of locking head for a window stay.

In broad terms the invention comprises a window stay comprising a locking head to lock the head of the stay against forced opening, comprising a protrusion on the upper end of the sash mounting member providing a substantially flat contact face which is oriented to engage substantially squarely in the direction of forced opening of the sash against a barrier on the frame mounting member when the stay is closed.

Preferably the barrier on the frame mounting member comprises a metal edge. In addition optionally the protrusion providing the contact face against the barrier is formed of a plastics material or a softer metal such as aluminium.

The locking head of my invention is very suitable for use with four bar window stays. A four bar window stay consists of a long arm and a pivot joint between the frame end of the long arm and a frame plate and a pivot joint between the sash end of the long ann and a sash plate, a short arm and a pivot joint between the sash end of the short arm and the sash plate at a point spaced from the long arm-sash plate pivot joint and a pivot joint between the frame end of the short arm and the frame plate at a point spaced from the long arm-frame plate pivot joint.

DZSCRIPTION OF DRAWINGS A preferred form of the locking head of the invention is illustrated, by way of example, in the accompanying drawings, wherein: Fig. 1 is a view of a window etay incorporating the preferred form locking head of the invention, from one side and in its fully extended or open position, Fig. 2 is a view of the stay incorporating the locking head of Fig. 1 in its closed position, Fig. 3 is an end view of the stay in the direction of arrow A in Fig. 2, Fig. 3A is similar to Fig. 3 but with the sash plate protrusion removed and showing only the bead of the stay, and Fig. 4 shows the stay incorporating the preferred form locking head fitted to the frame and sash of a window.

DESCRIPTION OF PREFERRED EHBODNENTS The stay illustrated in the drawings is a four bar friction stay having a short arm 1 and a long arm 2. The arms are typically formed from stainless steel (or aluminium) for example. The frame ends of the short arm 1 and long arm 2 are pivotally connected to a frame plate 3 for aecuring to the frame of a window (see Fig. 3) by way of pivot joints S and 9. The frame plate 3 is suitably formed from metal such as stainless steel. The sash end. of the short arm 1 and long arm 2 are pivotally connected to a sash plate 6 for securing to the sash of the window, by way of a pivot joints 7 and 8.In the preferred form stay shown in the drawings the sash plate 6 is formed by invention moulding from a plastics material such as acetyl or other wear resistant synthetic material, but the sash plate could alternatively be formed of metal and particularly a softer metal such as aluminium.

The top end of the plastic sash plate 6 is formed with a protrusion 13 (see Fig. 1). A recess 14 is formed in an integral enlarged head 15 of the frame plate 5. The protrusion 13 and recess 14 each preferably (but not essentially) have an adjacent downwardly sloping land 13a and 14a as shown. When the window stay is closed, the sash plate 6 will move such that the protrusion 13 engages into the recess 14 as shown in Fig. 2.

When the stay is fully closed and the protrusion 13 is fully engaged into the recess 14, the head of the window is locked and cannot be opened by force or prising open between the top of the window sash and the window frame. The locking mechanism can again only be opened by proper opening of the window by pushing on the bottom of the sash from within.

As stated the protrusion 13 ii formed in the plastics material of the saah plate, and the recess 14 consists of a cutout in the head 15 which is formed of metal at the top of the frame plate. The contact face 13b of the protrusion 13 (see Fig 1) squarely engages a corresponding barrier face of the recess 14, which is preferably a metal edge 14c, in a direct abuttment.

It is very difficult for the protrusion 13 to be dislodged from the recess 14 under force between the sash and window frame.

Also, a screw hole 16 ie provided so that a screw may fix the plastic moulding to the side of the sash very close to where loads would be applied during such force, to prevent breakage (see Fig. 4).

The foregoing describes my invention including a preferred form thereof. Alterations and modifications as will be obvious to those skilled in thc art are intended to be incorporated within the scope hereof a. defined in the following claims.

Claims

1. A window stay incorporating a locking head to lock the head of the stay against forced opening, comprising a protrusion on the an end of the sash mounting member of the stay providing a substantially flat contact face which is oriented to engage substantially squarely in the direction of possible forced opening of the sash against a barrier on the frame mounting member of the stay when the stay is closed.

2. A window stay as claimed in claim 1, wherein the barrier on the frame mounting member comprises a metal edge extending gonerally at right angles to the frame mounting member of the window stay.

3. A window stay as claimed in claim 2, wherein the protrusion providing the contact face against the barrier ie formed of a plastics material or a metal which is softer than the metal of the barrier.

4. A window stay incorporating a locking head substantially as herein described with reference to the accompanying drawings.