The invention relates to stays and in particular to door or

window stays for connecting a movable leaf to a fixed frame to

allow the leaf to open out of and close into the fixed frame.

A stay of this type comprises an elongate base member for connection to a frame and an elongate arm for connection to

the leaf . The arm is connected to the base member by a

linkage that constrains the arm to move in a plane generally parallel to the plane of the base member between a position in

which the arm overlies the base member (the position in which

the leaf is closed into the frame) and a position in which the

arm is to one side of the base member and at an angle to the

base member (when the leaf is opened out of the frame) . The

links of the linkage are connected to the arm by solid rivets

to provide pivotal connections between the links and the arms.

Such stays have to be capable of resisting the significant

forces that may be applied to the stay when an attempt is made

to lever the leaf out of the frame. When this happens, the

most significant forces are often those tending to separate

the arm from the base member in a direction normal to the

plane of the base member. The base member is connected to the

frame by screws passing through the base member and the arm is

connected to the leaf by screws passing through the arm at

points intermediate the rivetted connections between the arm and the links.

At the arm, the spacing between the fixings and the pivot

points between the arm and the links means that forces tending to separate the arm and the base member cause the links to

apply forces to the arms which tend to bend the arm about an adjacent fixing point. This decreases the resistance of the

stay to such unauthorized entry.

According to the invention, there is provided a door or window stay for connecting a movable leaf to a fixed frame and comprising an elongate base member for connection to the frame

and an elongate arm for connection to the leaf, the arm being

connected to the base member by a linkage that constrains the arm to move in a plane generally parallel to the plane of the

base member between a position in which the arm overlies the

base member and a position in which the arm is spaced to one

side of the base member and at an angle thereto, the linkage including a longer link and a shorter link, the shorter link

having first and second ends, a first end of said shorter link

being pivotally connected to the base member and the second

end of said shorter link being pivotally connected to said arm at a point of the arm adjacent a first end of the arm, said

pivotal connection between the second end of the shorter link

and the arm being by a hollow rivet through which a fastening

is possible to connect the arm to a leaf.

By having the fixing extending through the pivot between the

shorter link and the arm, there is no lever arm between the

rivet and the fixing to cause bending of the arm about the

fixing.

The following is a more detailed description of some

embodiments of the invention, by way of example, reference

being made to the accompanying drawings in which:-

Figure 1 is a plan view from above of a window stay,

Figure 2 is a section through an arm of the stay of Figure

1 showing a first form of aperture for receiving a first form

of rivet, Figure 3 is a cross section through the first form of rivet,

Figure 4 is a side elevation partly in section of the arm

with the first form of aperture connected to a shorter link of

the stay by the first form of rivet,

Figure 5 is a cross-sectional view of a second form of

rivet,

Figure 6 is a side elevation partly in section of the arm of the stay of Figure 1 with a second form of aperture and

connected to the shorter link by the second form of rivet.

Figure 7 is a perspective view of an end of the window stay

of Figures l and 2 with the arm of the stay removed for

clarity and showing an alternative form of end cap fitted to a base member of the stay,

Figure 8 is a side elevation of the end of the base member

and the end cap of Figure 7 showing an end of the arm engaging

the end cap, and

Figure 9 is a section of the line IX-IX of Figure 8. Referring first to Figure 1, the stay comprises an elongate

base member 10 provided with two parallel channels 11 extending along respective side edges of the base member 10.

A linkage indicated generally at 12 connects the base member to an arm 13. The linkage comprises a longer link 14, an

intermediate link 15 and a shorter link 16.

One end of the longer link 14 is pivotally connected by a

rivet 17 to the base member 10 towards one end of the base member 10. The other end of the longer link 14 is pivotally

connected by a rivet 18 to the arm 13, intermediate the ends

of the arm. A slider 19 is carried by the base member 10 and has side edges engaging in respective channels 11 to guide the

slider 19 for sliding movement to and fro along the base

member 10. The intermediate link 15 has one end pivotally

connected by a rivet 20 to the slider 19 and the other end

pivotally connected by a rivet 21 to a point intermediate the

ends of the longer link 14.

The shorter link 16 has one end pivotally connected by a

rivet 22 to the slider 19 and has the opposite end pivotally

connected by a rivet 23 to a point on the arm 13 adjacent an

end 24 of the arm which is triangularly shaped. The spacing

between the pointed end and the axis of the rivet 23 may be

15mm to 30mm and preferably 19mm to 25mm.

The base member 10 is provided with fixing holes 25 and has

an end cap 26 at one end for receipt of the pointed end 24 of

the arm 13 in a manner described below. The arm is provided with fixing holes 27, with the rivet 23 providing a further

fixing hole in a manner now to be described.

Referring next to Figures 2, 3 and 4, in a first embodiment,

the arm 13 is provided with an aperture indicated generally at

27 having an initial bevelled portion 28 extending from one

end of the aperture 27 and a cylindrical portion 29 extending

to the other end of the aperture 27. This aperture is for

receiving a rivet 23 shown in Figure 3 and having a hollow cylindrical body and a flange about one end having a bevelled

generally radially extending surface matching the bevel in the

aperture 27.

The shorter link 16 is also provided with an aperture (see

Figure 4) which corresponds to the aperture 27 in the arm 13

but is oppositely arranged (i.e. the bevelled portion of the aperture is the lowermost portion) . The rivet 23 fits through

the aperture in the shorter link 16 and through the aperture

27 in the arm 13 where it is swaged to extend into the

bevelled portions 28 and so connect the parts.

In an alternative embodiment shown in Figures 5 and 6, the

rivet 23 is provided with a flange having surfaces lying in

planes normal to the axis of the rivet 23 and the arm 13 and the shorter link 16 are provided with apertures including

larger and smaller diameter portions extending from respective

opposite ends of the associated aperture with a step between

these portions. The flange and the head of the rivet extend into the larger diameter portions to form the connection.

In either of these arrangements, a washer (not shown) may

be provided between the arm 13 and the shorter link 16.

Hollow rivets of this general kind are shown in GB-A-2237059

and NZ-A-212599/213772.

In use, the stay is for connecting a movable window leaf to

a fixed window frame. In an arrangement where the leaf and the frame are rectangular, two stays are used connected

between respective opposite edges of the leaf and associated

edges of the frame. The base member 10 is fixed to the frame

by fastenings passing through the holes 25. These fastenings

may be screws. The arm is similarly connected to the leaf by

fastenings passing through the holes 27 and the rivet 23.

Again, these fastenings may be screws. The linkage 12 constrains the arm 13 to move relative to the

base member 10 in a plane parallel to the plane of the base

member 10. The linkage moves between open positions and a

closed position. In the open positions, the arm 13 is spaced

to one side of the base member 10 and extends at an angle to

the base member 10, as shown in Figure l. In the closed position (not shown) , the arm 13 overlies the base member and

the pointed end 14 extends into the end cap 26. The function

of the end cap is to capture the pointed end of the arm 24, to

guide the arm 13 to ensure it moves into a position where it

overlies the base member 10 and to hold it in position once closed.

If unauthorized entry is attempted through the window, a common way of achieving such unauthorized entry is to insert

an implement between the frame and the leaf to lever the leaf

out of the frame. If this is done between two adjacent sides

of the frame and the leaf carrying a stay, the effect is to

try and separate the arm 13 from the base 10; that is to say

to move the arm in a direction generally normal to the plane

of the base 10 (and possibly to move the arm 13 sideways as

well) . The presence of the fastening through the rivet 23

means that the shorter arm 16 provides no lever force on the

fastening. It also thus provides no lever force on the other fastening through the holes 27. This increases substantially

the strength of the stay in resisting these forces. This can

provide increased security or can allow the arm 13 to be made

of thinner gauge metal than would otherwise be required.

It will be appreciated that a rivet 23 of the kind described

above with reference to Figures 2 to 6 can also be used in

place of the solid rivets 17,18 of the longer link 14.

It will be appreciated that a similar arrangement may be

applied to stays other than stays of the kind described above

with reference to the drawings. In particular, the

arrangement may be applied to a stay of the kind described with reference to Figures 8 to 10 of GB-A-2247914. An end cap

of such a stay is shown in Figures 7 to 9.

Referring to those Figures, the arm 13 is provided with a

pointed end 40 (see Figure 9) which projects from the arm 13

to one side of the centre line of the arm 13, as viewed in

Figure 9. In addition, an end cap 50 is fixed to the frame

for the purpose to be described below.

The end cap 50 comprises a plastics moulding providing a

base 51 from which project parallel side walls 52 with

transverse walls 53a.,53 _ extending between the side walls 52.

As seen in Figures 7 and 8, the side walls 52 have upper edges

54 which extend at an angle from one end of the base 51 to a

first transverse wall 53a and then extend parallel to the base to the second transverse wall 53b.. The side walls 52

terminate at the second transverse wall 53 which in turn is

spaced from the other end of the base 51.

Of course, the end cap 50 may be of metal.

A tongue 55 extends from the second transverse wall 53 and

is provided with a fixing aperture 56.

As seen in Figures 7 and 8, the base 51 is provided with a

fixing point 57 between the angled portions of the side walls

52 through which a screw 58 (Figure 8) can pass to fix the end

cap 50 to a window frame member 59 with the second end of the

base member fitting into the corner of the window frame, as seen in Figure 8. In this position, the spacing between the

second transverse wall 53 and the other window frame member 60 forming the corner is such that the end of the base member 10

fits in the slot so formed between the transverse wall 53 _ and

the frame member 60. This assists in preventing unauthorized

removal of the channel member and so of the friction stay.

The tongue 56 is sized to fit into the base member 10

between the channels 11 so that the fixing aperture 56 is in register with a hole in the base member 10. A screw can then

be passed through the holes and into the window frame to

reinforce the fixing of the window stay.

In this position, a recess 61 formed between the transverse walls 53 is aligned with the pointed end 40 at the end of the

arm 13. When the window is closed, the end 40 enters the

recess, so locking the arm 13. As seen in Figure 9, the

interior of the recess 61 is shaped to be a close fit around

the projection 40.

The end cap 50 provides increased security and also it is

not necessary to drill into the window frame to make a recess for receipt of the end 40. Such drilling can be difficult and

time consuming.

It will be appreciated that, in such a stay, separation of

the arm 13 from the base 10 is resisted by engagement of the end of the arm with the wall of the end cap. This provides a

force tending to bend the arm around the fastening closest to

the pointed end of the arm. If, as in a prior proposal, which

is as Figure 1 but omits the hollow rivets, fastenings extend only through the two holes 27 on the arm 13, then the length

of the lever arm will be quite long and the bending forces

around the fastening consequently great. However, in the stay

described above with reference to the drawings, the use of a fastening extending through the hollow rivet 23 not only has

the benefit of eliminating lever arm forces from the shorter link 16 but also reduces the lever arm length between the tip

of the arm and the fastening. As will be seen from Figure 1,

the fastening fastened through the hollow rivet 13 is very

close indeed to the end of the arm - usually between 15mm and

30mm, preferably between 19mm and 25mm.