GB2205127A - Scissor action window stay - Google Patents

Abstract

The window stay comprises first and second mounting plates 11, 12, a first arm 14 pivotally coupled to the first mounting plate 11, and a second arm 14 pivotally coupled to the second mounting plate 12. The first and second arms 14 are pivotally coupled together in their length by a pivot joint 17. A respective link arm 19 is pivotally coupled at one end to each of the first and second mounting plates 11, 12 and pivotally coupled at its other end to a respective one of the second and first arms 14. The stay can be used to mount a window sash in a window frame in a projected hung arrangement such that it remains parallel to the frame throughout its movement. Stops 22 define fully open and fully closed positions. <IMAGE>

Description

"A Window Stay and Window Mounting Arrangement" This invention relates to a stay for use in the mounting of a window sash in a window frame and to a mounting arrangement for a window sash in a window frame.

Normally, projected hung window sashes, i.e. where the window sash in an open position projects from the window frame, are either top hung or side hung. A top hung sash is when the window stays are attached near the upper end of the sash and a side hung sash is when the stays are positioned at the top and bottom of the sash. In either arrangement, a side edge of the sash remains closely adjacent the window frame during the range of most normal open positions of the sash between fully closed and fully opened.

Weather-proofing of a window is a prime requirement and thus, with projected hung windows, there is a need for the window stays supporting the sash to be operative so that upon closing there is a "pull in" function which ensures correct and uniform fitment of the sash within the frame.

Accordingly, weather seals present with the sash/frame can be correctly compressed to seal the sash within the frame. As the sash effectively closes progressively due to the aforementioned edge, which is always a-djacent the frame, forming a leading edge, the correct and effective weatherproofing can not always be achieved without particular attention being paid to the accuracy of pivot centres and the actual stay geometry.

The closeness of one edge of the sash to the frame can present difficulties when ventilation requirements are considered. For example, in those climatic conditions where ventilation is not assisted by airflows created by external air movements, i.e. wind, it is not always possible to achieve adequate ventilation without opening the sash to such an extent that the unobstructed opening formed presents a potential hazard in that a person can fall through the window.

Other disadvantages associated with projected hung windows are privacy in service areas, such as bathrooms and toilets and security. In the latter case windows cannot be left open and at the same time provide security without the fitting to sash and frame of security devices designed to limit the degree of openess of the sash.

It is known to mount a sash in a frame by a pair of window stays having a scissor action so that the sash during opening and closing moves parallel or substantially parallel to the frame. Such a window stay is for example disclosed in U.S.

Patent Specification 3722142 of Anderberg. To achieve the scissor action such a stay requires sliding elements in its construction. These sliding elements lead to increased manufacturing costs as well as often presenting operational problems. For example, it is known that it is difficult to achieve uniform and required levels of friction with sliding elements, especially dynamic friction, and this can lead to the stay being difficult to operate and/or at certain degrees of opening unable to hold the sash open especially in windy conditions. Also, sliding elements are exposed to dust, dirt etc and their operation can be imparred by the presence of dust and dirt in the sliding channels, grooves etc.

The present invention has, as one object, to provide a window stay which can be utilized to mount, in a projected hung arrangement, a window sash in a window frame, yet overcome, or at least go some way to overcoming, the aforementioned disadvantages often associated with projected hung sashes and known scissor type action stays.

A further object is to provide a mounting arrangement for a window sash in a window frame whereby the sash is mounted in a projected hung manner but does not have some or all of the aforementioned disadvantages often associated with projected hung sashes and known scissor type action mounting arrangement.

Broadly in one aspect the present invention provides a window stay comprising first and second mounting plates, a first arm pivotally coupled to said first mounting plate, a second arm pivotally coupled to said second mounting plate, said first and second arms being pivotally coupled together in their length by a pivot joint, a link arm pivotally coupled at one end to each of said first and second mounting plates and pivotally coupled at their other ends to said second and first arms respectively.

In the foregoing and the description which follows the term "mounting plate" is taken to mean either a single plate to which the arms are pivotally coupled or a pair of separate plates each of which is pivoted to an end of an arm.

The following more detailed description which follows will relate to a preferred embodiment of the invention and reference will be made to the accompanying drawing which illustrates the window stay, when viewed in elevation in the fully open position. It will be appreciated that in the fully closed position the mounting plates lie substantially one over the other with the arms and link arms sandwiched therebetween.

The stay 10 comprises first 11 and second 12 mounting plates which as noted above can each be of one or two pieces or sections though for ease of fitment and accuracy of centres the one piece design as illustrated is to be preferred. The mounting plates 11 and 12 are coupled together by a pair of arms 14. Each arm 14 is coupled to the respective mounting plate 11 and 12 by a pivot joint 15 which is located at the end of the arm 14 and preferably at the end of the mounting plate. As can be seen in the drawing the pivot joint 15 and hence the axis thereof is offset from the longitudinal centre line of the mounting plate. The offset is toward the outside edge 16 of the mounting plate The arms 14 are themselves joined together in their length by a pivot joint 17.This pivot joint 17 is also offset relative to the longitudinal centre line of the arms 14 and is positioned nearer to the ends of the mounting plates 11 and 12 having the pivot joints 15.

The other ends 18 of the arms 14 are each pivotally coupled to a link arm 19. The link arms 19 are pivotally coupled to the mounting plates 11 and 12 by pivot joints 20. Pivot joints 20 and the pivot joints 21 (coupling link arms 19 to arms 14) are offset as shown in the drawing to the respective centre lines of the mounting plates and link arms.

Each mounting plate 11 and 12 has a pair of upstands 22 which form stops to limit the extent of movement of the link arms 19. These stops 22 define the fully open and closed positions of the stay. In the drawing the link arms 19 are shown as engaging the stops 22 which are adjacent the inner edges 23 of the mounting plates 11 and 12 as a result of the stay being the fully open position.

The pivot joints 15, 17, 20 and 21 can either be simple bearings friction bearings or a mixture of both types of bearing. For example pivot joints 15 and 20 could be of a friction type and the other bearings of a simple plain bearing type. The friction bearings can be of the type described in New Zealand patent specifications 144922, 162919, 195036, 196479, 202214 and 223803.

In use of the stay the mounting plates 11 and 12 are mounted in a conventional manner to the opposite side edges of the respective window sash and window frame. Openings 13 are provided in the mounting plates 11 and 12 to permit the plates to be mounted by suitable mechanical fastenings. The sash is thus supported by the pair of stays in a position where it lies within and hence substantially parallel to the frame. Thus as it is moved to and from the closed position in the frame the stays operate with an action that the sash moves parallel to the opening defined by the frame. The link arms 19 control the motion and allow for the change in depth of the scissor assembly without vertical movement of the sash relative to the frame. The stops 22 prevent "toggle over" of the link arms 19 at the closed position and to maintain the pull-in of the sash.Stops 22 also limit the extent to which the stay can "open" as illustrated in the drawing, It will be appreciated that unlike conventionally mounted projected hung windows no side edge of the sash is substantially closer to the frame than any other at all open positions of the sash or during opening and closing of the sash. This action of the stay is unlike conventional scissor type stays as it is achieved without the need for sliding elements.

The window mounting, which a pair of stays of the present invention provides, allows excellent weather-proofing to be achieved as the sash closes directly in one movement into the frame and thus compresses in an uniform manner any weather seal present in the window construction. At the same time the fact that the sash can be supported entirely away from the frame allows for effective ventilation, yet can provide the required degree of privacy in service areas such as toilets, bathrooms etc. By limiting the opening of the sash the window can be made secure from unauthorised entry from without or can prevent people from falling therethrough.

Claims (8)

What We Claim is:-

1. A window stay comprising first and second mounting plates, a first arm pivotally coupled to said first mounting plate, a second arm pivotally coupled to said second mounting plate, said first and second arms being pivotally coupled together in their length by a pivot joint, a link arm pivotally coupled at one end to each of said first and second mounting plates and pivotally coupled at their other ends to said second and first arms respectively.

2. A window stay as claimed in claim 1 wherein said mounting plates include limiting means for limiting the extent of pivotal movement of said link arms.

3. A window stay as claimed in claim 2 wherein said limiting means comprise a pair of spaced apart upstands formed from the parent material of the mounting plates.

4. A window stay as claimed in any one of claims 1 to 3 wherein the axis of the pivots coupling the arms and the link arms to the mounting plates are offset to the respective longitudinal centre lines of the mounting plates, said offset being toward the outer edge of each said mounting plate.

5. A window stay as claimed in any one of claims 1 to. 4 wherein the pivot joint coupling the arms in their length is offset relative to the longitudinal centre lines of said arms and is located nearer to the pivots joining said arms to said link arms than the pivots joining said arms to said mounting plates.

6. A window stay as claimed in any one of the preceding claims wherein at least some of said pivots are friction pivot joints.

i. A window stay as claimed in any one of the preceding claims wherein at least one of said mounting plates is formed in two parts with one part complete to said arm and the second part coupled to said link arm.

8. A window stay substantially as herein described with reference to the accompanying drawing.