GB2087972A

GB2087972A - Improved window stay

Info

Publication number: GB2087972A
Application number: GB8133901A
Authority: GB
Original assignee: Arthur Shaw Manufacturing Ltd
Current assignee: Arthur Shaw Manufacturing Ltd
Priority date: 1980-11-25
Filing date: 1981-11-10
Publication date: 1982-06-03
Also published as: GB2087972B

Abstract

The invention concerns window stays having at least two arms (5, 6) pivotally connecting two mounting plates (1, 3) for respective mounting on a fixed frame and sash, the pivot points (7) may be friction rivets. In the stay there is a support and stop plate (13) mounted adjacent one pivot and having an arcuate rib (18) concentric with the pivot but spaced radially so that a land is engaged by the arm (5) to support the loads on movement of the arm. A block (16) provides a stop or abutment limiting movement of and supporting the stay arm (5) in the extreme unfolded position. In another embodiment, the support plate has an extension with ribs and lands engaged by the underside of the second longer arm of the stay and the stop is of a different form. The support plate is a plastics moulding. Improved load support, guiding and control with reduced stress on the pivot joints are obtained by the arrangement of the lands and the principle may be applied to a wide range of stays of this kind. <IMAGE>

Description

SPECIFICATION Improved window stay This invention relates to an improved window stay of the kind having at least two arms or links pivotally connected to mounting plates for respective fixing to a sash and the fixed frame of the window. Usually, each sash is mounted for opening and closing movements by a pair of such stays, one on each opposed side of the sash and associated frame. The sash may be hung on such stays for top or side opening relative to the frame.

In this kind of window stay, the pivot connections may comprise rivets which are arranged to provide joints having frictional restraint, however other types of construction can be used. Alternative constructions may comprise simple pivot pin connections with possible arrangements to vary or adjust frictional restraint, such as nut and bolt or spring or resiliently loaded friction devices.

In such stays, on opening and closing movement the arms or links (herein also generally called arms) move relative to the mounting plates and, through the pivot connections, have to support the substantial weight of the glazed sash.

This weight induces loads in the pivot connections and the arms or links, and such loads may be increased by wind-loading on the sash and twisting or bending that may arise due to various factors including the attitude of the sash with respect to the frame.

As the arms and the mounting plates are conventionally made of metal, it is desirable to ensure that on relative movement there is no metal to metal contact as the arms sweep over the associated mounting plate. However, it is found that a simple washer or spacer between the arm and the mounting plate and around the pivot is insufficient as it cannot provide adequate loadtransmitting support acting between the arm or link and the associated plate having regard to the high loads which can arise in practice. It is found that failure of the pivot, particularly when provided as a rivet, is due to overstressing of the rivet through the loads applied through the end of the arm which may act as a lever applying both sideways and axial loads to the pivot.

It is also found necessary to ensure a smooth action on such relative movement to avoid load differentials arising between a pair of stays supporting the sash on the frame as such differentials may exceed the designed strength of the pivot joints which fail, or cause buckling or distortion of the arms or links.

It is an object of this invention to provide an improved window stay of the foregoing kind in which an arm is adequately supported for smooth movement relative to the associated mounting plate.

It is a further object of this invention to provide an improved window stay of the foregoing kind in which a stop for limiting movement of an arm is provided whilst maintaining adequate support for the arm.

According to this invention, we provide a window stay of the kind specified wherein adjacent to a pivot joint connecting an arm to a mounting plate of the stay there is a support located on the mounting plate and the support is provided with an upstanding rib providing a land having a major arcuate portion concentric with the pivot axis of the joint but spaced therefrom, the land being engaged by the arm during pivotal movement of the arm relative to the support and the mounting plate.

By this invention, the arm is supported by engaging the land which provides a load transmitting surface spaced from the pivot axis so as to distribute loads to the mounting plate whilst permitting smooth sliding action of the arm over the land.

Preferably, the support comprises a plate portion formed with the upstanding rib. The support may be located on and fixed to the mounting plate by a screw or rivet or other fastening.

Accordingly, the support may be interposed between the mounting plate and the arm and located on the mounting plate in a simple manner whereby predetermined spacing and support for the designed function of the stay can be accommodated.

It is also preferred that the support is located on and fixed to that mounting plate adapted in use to be secured to the fixed frame of the window. Thus the load of the movable sash is transmitted to the fixed frame.

The support may also comprise a block providing an abutment for engagement by the arm to limit pivotal movement of the arm relative to the mounting plate when the arm has travelled the full extent of the arcuate portion of the land.

By such an arrangement with an integral abutment or stop, the arm can be supported by the land for loads in one direction whilst the abutment supports for loads in another direction.

Thus, by disposing the extent or plane of the land and the abutment face in planes normal to each other, the stay is arranged for top or side hung applications with adequate load supporting and transmitting surfaces.

Preferably, the abutment comprises two relatively inclined faces engageable by a notch formed in the stay arm. The block may include a seating surface for supporting and engaging the arm at the extreme limit of pivotal movement. The seating surface may comprise a nib or platform.

The provision of the notch in the arm assists in providing a stay of compact form and provides a substantial area of the arm for engaging with the abutment or stop for transmitting impact or drop loads that may arise in service.

The support may also comprise an extension plate portion extending from the block opposed to the upstanding rib, the extension plate portion providing a secondary land for engagement by a second arm of the stay connected to the mounting plate by a second pivot, the second pivot being spaced from the first mentioned pivot with the second arm being adapted for folding pivotal movement to overlie the mounting plate and to engage the secondary land.

The secondary land provides a bearing surface engageable by the second arm so as to transmit loads arising through the second arm and the sash to the mounting plate. This secondary land has particular application for long armed stays and for stays in a window wherein the sash is side hung on a pair of stays for hinging movement about a vertical axis. In such application of the invented window stay, the vertical components of the loads arising from the weight of the glazed sash and any wind or sideways loads are transmitted through both the secondary land engaged by the second arm and by any seating surface provided on the support engaged by the first mentioned arm.

Preferably, the secondary land is provided by at least one rib upstanding from the extension plate portion of the support.

The secondary land may comprise an upstanding rib having a face engageable with the second arm and the said face being inclined as a ramp so that on folding inward movement of the second arm, the second arm is displaced causing lifting of the second arm relative to the mounting plate to guide and control movement of the sash as it closes in the fixed frame.

By providing the inclination or ramp configuration to the land engaged by the second arm, by suitable design for the particular size and load bearing requirements of the stay, controlled movement and support of the second arm and the sash is achieved to ensure the desired correct alignment of the sash when it is approaching the closing position as the stay arms fold inwards over the mounting plate and the support.

The secondary land may comprise a further upstanding rib and other surfaces contiguous therewith extending at substantially the same inclination as a discrete series of ramps for supporting and guiding movement of the second arm.

Conveniently, the extension plate portion of the support overlies the mounting plate and is located and fixed to the mounting plate by screw, rivet or other fastening.

Furthermore, it is preferred that the support is a moulding of low friction plastics material, such as acetal resin, and the rib, block and any secondary ribs or surfaces may be moulded integrally.

Other features and advantages obtained by this invention will be explained later herein with reference to the accompanying drawings wherein.

FIGURE 1 is a side elevation of an exemplary window stay according to this invention shown in the partially open position; FIGURE 2 is a detail from Figure 1 with the stay shown in the fully open position; FIGURE 3 is an exploded isometric view of the detail construction as depicted in Figure 2; FIGURE 4 is a plan view of a second form of support for a window stay similar to that shown in Figure 1; FIGURE 5 is a section on V-V of Figure 4; FIGURE 6 is a section on VI--VI of Figure 4; FIGURE 7 is a section on VIl-VIl of Figure 4; FIGURE 8 is a section on VIll-VIll of Figure 4; and FIGURE 9 is a side view of the support shown in Figure 4.

With reference to Figures 1, 2 and 3 of the drawings, the stay comprises a first mounting plate 1 adapted by means of holes 2 to be fixed by screws, rivets, or other suitable fasteners to the inside face of the rebate of a fixed window frame (not shown). A second mounting plate 3 is adapted by means of holes 4 to be fixed by screws, rivets or other fasteners to the side of a sash (not shown).

Extending between the two mounting plates 1, 3 is a short arm or link 5 and a longer arm or link 6. The ends of the arms 5, 6 are pivotally connected to the respective mounting plates 1, 3 by respective joints 7. The joints 7 are generally of known type of construction.

Each joint 7 is similar and comprises a rivet 8, a washer 9 seated in a counter-bore 10 in the end of the arm, and a spacer 11. The rivet shank extends through a piercing 1 2 in the associated mounting plate and the tail of the rivet is clinched at the rear of the plate. The clinching of the tail of the rivet may be arranged to prevent the rivet turning relative to the mounting plate by forcing the rivet tail into the square of the piercing 12. The clinching pressure may be such as to provide frictional restraint in the joint so that the stay can hold the sash at any adjusted position.

According to the improvement of this invention, the mounting plate 1 has a support 13 fixed thereto by a screw or rivet 14 extending through a bore 26 in the plate 1. Preferably, the support 13 is a moulding of suitable plastics material, such as acetal resin, having low friction properties and having resistance to wear and weathering.

The support 13 is generally rectangular in plan view and has a plate portion 1 5 and a block 16 at one end. The plate portion 15 is arranged to be interposed between the arm 5 and the mounting plate 1 and has a keyhole aperture 1 7 which is concentric with the axis of the pivot joint 7. The rivet shank with spacer 11 extends through the aperture 1 7.

The plate portion 1 5 is formed also with an upstanding rib 1 8 which has a flat upper face providing a land 1 9 which is engaged by the underside face of the arm 5. The rib 1 8 has a major arcuate portion that extends concentrically with the axis of the pivot joint but spaced radially therefrom. Preferably, the distance of the radial spacing is as great as possible so that the support provided to the arm by the land on the rib is at an optimum having regard to the size and type of support and mounting plate.The arcuate shape of the rib, which may be of any suitable section providing the flat land, and the spacing from the pivot axis ensures that the arm is supported at positions displaced from the pivot axis during all effective pivotal movement of the arm from the closed to fully open position (see Figure 2). The opposed end portions of the rib are blended outwardly to suit the plan shape of the plate.

As will be understood, the land on the rib provides a low friction surface of which the area in contact with the arm is constant during sweeping movement of the arm so that no change in frictional resistance occurs during movements of the arm. Loads applied to the arm, particularly bending or twisting loads are transmitted to the substantial area of the plate engaging the rigid mounting plate through the inter-engaged faces of the land and the arm. Furthermore, as the rib stands proud of the plate, it offers some protection against detritus in the window rebate entering the pivot joint.

According to another feature of this invention, the support includes an abutment or stop to limit the movement of the arm (see Figure 1) and this is provided by the block 16.

The block 1 6 provides an abutment with two inclined faces 20, 21 formed by a corner on which a notch 22 formed in the arm engages to limit further movement of the arm. The notch 22 provides two substantial transverse faces extending normally to the plane of the arm to provide an area in contact with the abutment for distributing impact or static loads arising with the sash in use. Furthermore, the notch 22 locates the arm to support it against twisting or bending loads such as arise from wind loads when the sash is fully opened. An additional supporting surface is provided by an inclined platform 23 on one side of a nib 24 projecting from the block and this gives an aligned rest for the arm in the fully open limited position.By the provision of an undercut 25 on the back of the block, further location of the support on the mounting plate is obtained as the undercut engages the edge face of the mounting plate and restrains the support against turning movement relative to the mounting plate. There is also a location lug 27 formed on the back of the plate portion 1 5 which seats in a hole 28 in the mounting plate 1.

As will be appreciated, during opening movement of the stay, the arm is supported by the land on the support, and at the fully open position, the land is still engaged by the arm and the arm also rests and engages the stop. The faces which support the arm extend in planes normal to each other so that loads and stresses arising from the weight of the sash, these being normal to one another in service, are properly distributed through the support to the mounting plate on which the support is located. Thus, the stay can be employed in the top hung or side hung positions.

The notch may be formed in several ways depending on the material of the arm, particularly thickness. If required, to prevent any tendency of the notched portion to cut into the faces of the block, the notched edges may be rolled, bent or otherwise smoothed over.

The support may comprise other forms of abutment, such as a plain inclined platform extending across the corner of the block which is engaged by a plain edge of the arm. However, there are design advantages in providing a notch in the arm for it provides clearance in certain sizes of stays.

With reference to the further Figures 4 to 9 of the drawings, there is depicted another form of support for use with a window stay having two arms of dissimilar lengths and having a construction substantially the same as shown and described with reference to Figure 1. The only difference of importance to understanding this invention is that this support is not designed for use in a window stay in which a notch is formed in the one arm. In view of the similarities, the foliowing description of this other form of support should be construed with reference to Figures 1 and 2 as necessary.

The support 30 is of substantially rectangular shape in plan view and is arranged to overlie a substantial length of the mounting plate and to be located and secured thereto by suitable fasteners (not shown) extending through counter-sunk holes 31 and 32.

Similar to the first embodiment, the support 30 has a plate portion 33 formed with a keyhole aperture 34 arranged to extend around the pivot for the shorter or first stay arm, and an upstanding arcuate rib 35 concentric with and spaced from the pivot axis of the first stay arm. The support 30 includes a block 36 providing a sloping stop face 37 against which the side edge of the arm of the stay abuts when it is in the fully unfolded position such as shown in Figure 2.

The support includes a further plate portion 38 which is a contiguous and integral extension from the block 36 and the plate portion 33. There is a raised platform 39 extending from the block 36 on the side opposed to the stop face 37 and this leads to an upstanding rib 40 which extends at about 200 to the longitudinal axis of the support.

Spaced from and parallel to the rib 40 is another rib 41 which leads to another raised platform 42.

The upper faces of the platforms 39 and 42 as well as the ribs 40 and 41 are arranged to be engaged by the underside of the longer second arm of the stay to provide support and load transmitting engagement supplementing that obtained by the engagement of the first arm of the stay with the arcuate rib 35.

As best shown in Figures 5, 7 and 9, the faces of the platforms 39, 42 and ribs 40, 41 are inclined relative to the flat base of the support to taper towards the side edge of the support which the second arm of the stay rides over on folding and unfolding movement. The angle and extent of the taper incline is selected to provide a ramp over.

which the second arm moves on operation of the stay. Thus, significant support of the second arm along its length is achieved to prevent twisting or bending due to the variations in loads or stresses.

Due to the ramp effect obtained by the inclined faces, when the sash is closed into the frame, the stay operates to effectively correctly align the sash into the rebate in which the stay is mounted.

The support is a moulding of acetal or other suitable low friction or wear resistant material, and may have suitable location means on the underside to locate it on the mounting plate to which it is to be secured. A small boss 43 is shown which would locate in a suitable complementary recess formed in the associated mounting plate.

This form of support has particular application for heavy duty stays wherein the arms are long and two such stays are intended to be employed to pivotally mount a sash for side hinging movement about a vertical axis.

The first described embodiment with the smaller length for the first arm support is preferred for applications where the sash is intended to be top hung for hinging movement about a horizontal axis.

The support may have other shapes in plan view to suit the mounting plate, and be secured to the plate by other arrangements. If desired, the support could be an assembly of two separate parts coupled or interlocked together. By such an assembly, a variety of sizes of arcuate rib portions with a range of radii could be provided for assembly to a block element.

It will be understood that the invention may be applied to various types of window stay of the kind specified, and the underside of the support may be formed to nest or mate with ribs, grooves or the profile of the mounting plate if desired.

Other forms of joints may be used in the stay, and the type of joint described is only exemplary of a wide range of suitable joints. In particular, different arrangements of rivetted assemblies can be employed with other types of rivets, and any suitable clinching and means for preventing turning of the rivet with respect to an associated arm or link can be employed. The rivet assembly need not have a washer which is received in a counter-bore in the arm or link, and the spacer between the plate and the arm or link can be omitted or varied. The rivet head can be located against turning movement with the rivet tail being arranged for rotation relative to the arm or link or mounting plate depending on the way in which the rivet is mounted in the assembly. The rivet head need not be received in a recess or the like.

Such changes are not considered within the scope of this invention but are mentioned for clarity of understanding of the types of joints which can be used.

Claims

1. A window stay of the kind specified wherein adjacent to a pivot connecting an arm to a mounting plate of the stay there is a support located on the mounting plate and the support is provided with an upstanding rib providing a land having a major arcuate portion concentric with the pivot axis of the joint but spaced therefrom, the land being engageable by the arm during pivotal movement of the arm relative to the support and mounting plate.

2. A window stay according to claim 1 wherein the support comprises a plate portion formed with the upstanding rib.

3. A window stay according to claim 2 wherein the plate portion is located on and fixed to the mounting plate by screw, rivet or other fastening.

4. A window stay according to any one of the preceding claims wherein the support is located on and fixed to that mounting plate adapted in use to be secured to the fixed frame of the window.

5. A window stay according to claim 4 wherein the support also comprises a block providing an abutment for engagement by the arm to limit pivotal movement of the arm relative to the mounting plate when the arm has travelled the full extent of the arcuate portion of the land.

6. A window stay according to claim 5 wherein the abutment comprises two relatively inclined faces engageable by a notch formed in the stay arm.

7. A window stay according to claim 5 or claim 6 wherein the block includes a seating surface for supporting and engaging the arm at the extreme limit of pivotal movement defined by the abutment.

8. A window stay according to claim 5 wherein the support further comprises an extension plate portion extending from the block opposed to the upstanding rib, the extension plate portion providing a secondary land for engagement by a second arm of the stay connected to the mounting plate by a second pivot, the second pivot being spaced from the first mentioned pivot with the second arm being adapted for folding movement to overlie the mounting plate and to engage the secondary land.

9. A window stay according to claim 8 wherein the secondary land is provided by at least one rib upstanding from the extension plate portion.

10. A window stay according to claim 9 wherein the upstanding rib of the secondary land has a face engageable with the second arm and said face is inclined as a ramp so that on folding inward movement of the second arm, the second arm is displaced causing lifting of the second arm relative to the mounting plate.

11. A window stay according to claim 10 wherein the secondary land further comprises a further upstanding rib and other surfaces contiguous therewith extending at substantially the same inclination as a discrete series of ramps for supporting and guiding movement of the second arm.

12. A window stay according to any one of claims 8 to 11 wherein the extension plate portion of the support overlies the mounting plate and is located and fixed to the mounting plate by screw, rivet or other fastening.

13. A window stay according to any one of the preceding claims wherein the support is a moulding of low friction plastics material.

14. A window stay of the kind specified and substantially as hereinbefore described with reference to the drawings of Figures 1,2 and 3.

1 5. A window stay of the kind specified and including a support substantially as hereinbefore described with reference to the drawings of Figures 4, 5, 6, 7, 8 and 9.