GB2257199A - Window stay - Google Patents

Abstract

A window stay comprises a frame mounting plate 10 and sash mounting plate 11 with a carriage 16 mounted for sliding movement along the frame mounting plate. The sash mounting plate is pivotally coupled 15 to the carriage. An arm 13 is pivotally coupled 14 at one arm to the sash mounting plate and pivotally coupled 14 at the other end to the frame mounting plate. A combination of abutment means 33 and 34 and abutment surfaces (25 and 27 Fig. 3) cause the carriage to be angularly displaced relative to the frame mounting plate at initial opening and final closing stages of operation of the stay. A pad 30 is provided on the frame mounting plate 10 and the carriage 16 slides during at least part of the operation of the stay over this pad. The pad provides the abutment means 33 and 34. <IMAGE>

Description

TITLE OF THE INVENTION "A WINDOW STAY" BACKGROUND OF THE INVENTION Field of the Invention This invention relates to improvements in window stays.

Discussion of the Background In our British patent specification GB00001487 there is described and claimed a window stay having a carriage which is mounted for sliding movement along a window frame mounting plate. The construction of the stay is such that at initial opening and final closing of the stay, the carriage is angularly displaced. This angular displacement provides pull-in of the sash into the window frame at the final stages of the closing. It therefore ensures the sash does not interfere with the sealing surfaces or seals of the window frame until final engagement therewith takes place. This avoids damage to the surfaces/seals and also ensure there is correct sealing engagement therewith. When the sash is of the overlap type the stay ensures that the sash flange does not foul with the frame.

The content of British patent specification GB00001487 is incorporated herein by way of specific reference.

SUMMARY OF THE INVENTION The present invention represents an advance over the aforementioned stay in that the stay of the present invention is able to carry loads and withstand loadings which size for size are greater (especially in cagement window applications) than the stay as described and claimed in British patent specification GBo0001487.

This is primarily achieved by the incorporation of a plastics material pad located on the frame mounting plate.

By using a plastics material pad, the abutment surfaces which, in conjunction with the configuration of the carriage cause the carriage to angularly displace, can be moulded integrally with the pad. Furthermore the plastics material pad will reduce the need for lubricants which are sometimes required when higher loadings are to be carried by the stay. Also in one form of the invention guide means to ensure the carriage moves longitudinally along the frame mounting plate can be provided in or by the pad.

Broadly therefore, the invention according to one aspect consists of a window stay comprising a frame mounting plate and a sash mounting plate, a carriage mounted for sliding movement along the frame mounting plate said sash mounting plate being pivotally coupled to said carriage, an arm pivotally coupled at one end to the frame mounting plate and at the other end to the sash mounting plate, there being means which causes the carriage to be angularly displaced relative to the frame mounting plate at the initial opening and final closing stages of operation of the stay, the window stay being characterised in that a pad of plastics material is provided on said frame mounting plate and over which the carriage slides during at least part of the operation of the stay, said pad providing abutment means which form part of the angular displacement means for interacting with the carriage to effect said angular displacement.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an elevation view of the stay in a partially opened position, Figure 2 is a sectioned end view of the stay in the closed position the section being taken on line B-B indicated in Fig 1, Figure 3 is a plan view of the carriage, Figure 4 is an underside plan view of the carriage, Figure 5 is a section along line A-A of Figure 3, Figure 6 is a plan view of the plastics material pad, Figure 7 is a side elevation view of the pad, Figure 8 is a section on line C-C of Figure 6, Figure 9 is a section on line D-D of Figure 6, Figure 10 is a section on line E-E of Figure 6, Figure 11 is a partial underside view of the pad with the carriage when the carriage is in the fully closed position, Figure 12 is a similar view but showing the carriage in the position after angular displacement at initial opening of the stay, and Figure 13 is an end elevation of the stay when in the closed position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Throughout the following description, reference will be made to a single stay in relation to a window sash and mounting frame but it will be appreciated that to mount a window sash in a window frame a pair of such stays will normally be employed. The stays can be mounted by their frame mounting plates to the side members of the frame (an awning window) or to the top and bottom members of the frame (a casement window).

Referring to Figure 1, the stay comprises a frame mounting plate 10 and sash mounting plate 11. Openings 12 are provided in both of plates 10 and 11 to enable the mounting plates to be respectively mounted to the frame F and sash S of a window construction.

An arm 13 is pivotally attached via pivot joints 14 to the frame and sash mounting plates. Pivot joints 14 can be of so called non friction or friction construction and can, for example, be of the type disclosed in British patent specifications 1163798, 1304830, GB0024491, 2094880, GB0207761 and 2237059.

One end of sash plate 11 is mounted via pivot 15 to carriage 16. The carriage is preferably formed of a plastics material such as nylon. As illustrated in Figure 1, carriage 16 has, after initial opening of the sash, been angularly displaced relative to frame mounting plate 10. During further opening of the sash carriage 16 can slide longitudinally along frame mounting plate 10.

As illustrated in Figure 2, frame mounting plate 10 comprises a flange 17 having an up stand 18 formed along one edge and return 20 extending therefrom. An upturned nib 21 is formed at the extreme edge of return 20. Extending longitudinally adjacent the free edge of flange 17 is a rib 19 used as a key for the location of and stiffening of pad 30.

Referring to Figures 3-5, carriage 16 is formed in one piece. On the upper surface of carriage 16 there is a rebate 22. On the underside of carriage 16 (see Figure 4), are projections 23 and 24. Projection 23 forms engagement surfaces 25 and 26 which in the preferred form of the invention are of curved shape when viewed in plan. Projection 24 also provides an engagement surface 27 which in the preferred form is of curved shape when viewed in plan.

The pad 30 can be of unit construction and formed of a suitable low friction combination plastics material such as acetal. In the preferred form, however, one end of pad 30 is formed by a separate but interfitting element 30a which is constructed from nylon. The nylon material exhibits better friction characteristics as a result of its interaction with the pivoting end of arm 13. It can be constructed in two pieces to provide for thermal expansion.

Pad 30 is positioned on flange 17 and located in place by elongate studs 31 which engage in suitably positioned and shaped openings (not shown). A circular locating stud 31' locates pad 30 in a longitudinal direction with respect to flange 17. Also a downward projection 42 engages in a cut-out (not shown) in the edge of flange 17. Rib 19 of mounting plate 10 fits in longitudinal groove 43 in pad 30.

Pad 30 provides three abutment surfaces, these being surfaces 32, 33 and 34. Surfaces 32 and 34 are, according to the preferred form of the invention, of .generally curved shape. The distance between abutment surfaces 32 and 33 is slightly greater than the distance between engagement surfaces 25 and 26 of projection 23.

When the stay is in the open position illustrated in Figure 1 the carriage can longitudinally slide along the guide pad 30. As a result straight surface 36 of the carriage engages against a surface formed by edge 37 of return 20 and nib 21. Edge surface 29 formed by projection 23 engages with the side edge 38 of pad 30.

The surface area indicated at 40 between the pair of dotted lines (see Figure 4) engages on surface 41 of pad 30. Furthermore edge 35 of projection 24 and edge 35' of projection 28 both engage with edge 51 of pad 30.

These sliding contacts all combine to support the carriage and guide it for longitudinal movement along the frame mounting plate. Due to loadings (either static or dynamic) applied to the stay there is, in some circumstances, the possibility of flexure of the carriage occurring with the result there is loss of contact between surface 29 and edge 38. In such a situation the two separate areas of contact between surfaces 35 and 35' and edge 51 prevent the carriage from angular displacement. Surfaces 35 and 35' are maintained in contact with edge 51 because any flexure in carriage 16 in this area is prevented by the carriage being effectively sandwiched between flange 17 and return 20.

As carriage 16 approaches final closing, curved engagement surface 27 engages abutment surface 34. As a result longitudinal sliding of carriage 16 ceases to take place. However, angular displacement of carriage 16 occurs. Projection 23 thus moves so as to locate between abutment surfaces 32 and 33 and projection 28 moves into curved recess 44 in pad 30.

The extent of angular displacement of carriage 16 is limited by the peripheral surface area 45 of carriage 16 contacting upstand 46 and edge surfaces 35 and 47 of projection 24 contacting edges 49 and 50 respectively of pad 30.

When in the fully closed position curved engagement surface 26 will generally come into contact with abutment surface 32. Thus if a force (other than a normal opening force applied to the latch side of the window sash) is applied to the sash (in the area commonly referred to as the hinge side, i.e. where the carriage is attached to the sash) there will be an interaction between surfaces 26 and 32 which will prevent the window from opening. Such a force can result, for example, from some leverage applied to the sash by someone trying to force access or by a negative pressure arising from high wind conditions.

At initial opening of the stay, engagement surface 25 will contact with abutment surface 33 and engagement surface 47 with abutment surface 50. This will cause reverse angular displacement of the carriage to take place. Thus projection 23 will move away from between abutment surfaces 32 and 33 so that once clear, the carriage can longitudinally slide along the frame mounting plate.

In an alternative arrangement the gliding pad 30 does not extend for the full length of longitudinal sliding movement of the carriage. In this form the pad terminates near the abutment surfaces and the carriage thus slides on flange 17. It will be appreciated that flange 17 will be constructed with a step such that the of the step thereof is aligned with surface 41 of pad 30 to form a continuous sliding surface.

gn the preferred form of the invention the sash mounting plate 11 is shown in one piece. As is known the mounting plate could be formed as two separate mounting plates one coupled to the carriage and the other to arm 13.

Pad 30 provides greater support for carriage 16 than the arrangement disclosed in British patent specification GB00001487 thus the stay is capable of carrying higher loads or applied loadings. It is also believed that because the abutments necessary to effect angular displacement of the carriage are formed integrally with pad 30 less manufacturing operations will be necessary to manufacture the stay. As a result construction of the stay will be more cost efficient. Also because the plastics material carriage 16 is generally in contact only with the plastics material pad 30, smoother operation will result especially as it is believed that lubricant will not be required when heavier loads or loadings are to be carried by the stay.

A problem which can arise when the stays are used in a casement arrangement is due to either incorrect dimensions of the sash or distortion of the sash. For example, if the glazier does not block the glass correctly into the sash the sash can distort diagonally as there is no support for the sash at the lockside of the sash. The end result is the sash sags downwardly and interferes with the arm of the sill mounted stay.

This can lead to the stay jamming or to the stay being crushed. Consequently this can lead to stay failure.

To overcome this problem a riser block 52 is provided at the lockside end of the stay. This block can be conveniently moulded with element 30a The riser block 52 has an upper surface 53, which is generally aligned with nib 21, and an inclined surface 54, Thus if the sash distorts any sag results in the sash engaging surface 54. As this surface is higher than arm 13 the sash is prevented from crushing the stay. Ramp surface 54 interacts with a sagging sash so as to cause the sash to be gradually lifted up as the sash is closed whereupon the sash becomes supported by surface 53.

While the foreging description relates to pad 30 being formed in one piece from plastics material this is only one means of achieving the desired result. For example, the pad could be of a die cast construction (e.g. of magnesium) having at least some of the surfaces with which the carriage engages coated in a low friction material such as Teflon (Reg. Trade Mark).

Claims (11)

CLAIMS:

1. A window stay comprising a frame mounting plate and a sach mounting plate, a carriage mounted tor sliding movement alonq the frame mounting plate said sash mounting plate being pivotally coupled to said carriage, an arm pivotally coupled at one end to the frame mounting plate and at the other end to the sash mounting plate, there being means which causes the carriage to be angularly ispd relative to the frame mounting plate at the initial opening and final closing stages of operation of the stay, the window stay beinq characterised in that a pad of plastics material is provided on said frame mounting plate and over which the carriage slide during at least part of the operation nf the stay, said pad providiuq oDuLmUnt means which form part of the angular displacement means for i ntQracti ng with the carriage to effect said angular displacement.

2. A window stay as claimed ill Claim 1 wherein the pad includes a first abutment means and said carriage.

includes a first engagement surface which co-operates with the first abutment means as the stay is moved from a closed position wlleby angular displacement of the carriage occurs.

3. A window stay as claimed in Claim 2 wherein the pad include a second abutment means and said carriage includes a second engagement surface which co-operates with the second abutment means as thc stay moves toward a closed position whereby angular displacement of the carriage occurs.

4. A window stay ac claimed in Claim 2 or 3 wherein the pad includes at least one edge surface with which d sliding surface of the carriage engages during sliding movement of the carriage on the pad.

5 A window stay as claimed in Claim 4 wherein the pad includes two edge surfaces.

6. A window stay as claimed in Claim 5 wherein the carriage includes at least a pair of sliding surfaces which are engageable with one of said edge surfaces.

7. A window stay as claimed in any one of Claims 2 to 6 wherein the pad includes a third abutment means and said carriage includes a third engagement surface which interengage following engagement of said first abutment means with said first engagement surface.

8. A window stay as claimed in any one of the preceding Claims wherein the pad includes a plurality of projections which engage in apertures formed in the frame mounting plate.

9. A window stay as claimed in any one of the preceding Claims further including a second pad which is located between said arm and the frame mounting plate in the area in which the arm is pivotally coupled to said fame mounting plate.

10. A window stay as claimed in any one of the preceding Claims wherein the pad is constructed from a non-plastics material but includes a low friction surface material on at least part of the surfaces with which the carriage engages.

11. A window stay substantially as hereinbefore described with reference to the accompanying drawings.