Window stays

1. A window stay, including:

a short arm coupled by pivots at each end to the frame mounting plate and the sash mounting plate; and

an elongate long arm coupled by pivots at each end to the frame mounting plate and sash mounting plate,

wherein the stay includes a first stop and a second stop, each acting between the short arm and the frame mounting plate as limiters at a fully open position of the window stay to substantially reduce buckling of the window stay at the fully open position;

wherein the second stop is a projection from the short arm configured to engage with the frame mounting plate.

2. The window stay of claim 1 wherein the first stop is a projection from the frame mounting plate configured to engage with the short arm.

3. The window stay of claim 2 wherein the projection from the frame mounting plate is configured to engage with a recess in the short arm.

4. The window stay of claim 1 wherein the second stop is configured to engage with a perimeter of the frame mounting plate.

5. The window stay of claim 1 wherein the frame mounting plate is engaged with an elongate disk having longitudinal edges and the disk includes a channel in which the second stop travels as the stay moves between closed and open positions.

6. The window stay of claim 1 wherein the geometry of the stay is such that, in a closed position of the stay, the pivot coupling the long arm to the sash mounting plate is situated between the pivot coupling the frame mounting plate to the short arm and the pivot coupling the sash mounting plate to the short arm.

7. The window stay of claim 1 wherein the sash mounting plate includes a sash mounting plate stop to act as a limiter at the fully open position of the stay.

8. The window stay of claim 7 wherein the sash mounting plate stop is a projection from the sash mounting plate configured to stop the long arm and/or the sash mounting plate stop is surrounded by a bulge in the sash mounting plate.

9. The window stay of claim 1 wherein the frame mounting plate includes a pressed form along a longitudinal edge of the frame mounting plate and/or at a high-load area of the frame mounting plate.

10. The window stay of claim 9 wherein the pressed form includes folds extending the frame mounting plate in both directions from a primary plane of the frame mounting plate.

11. A window stay, including:

a frame mounting plate;

a sash mounting plate;

a mounting, wherein the mounting is configured to attach the frame mounting plate to a window frame, and the mounting includes a bearing surface; and

a long arm including:

a central portion along a substantial length of the long arm; and

offset portions on either side of the central portion,

wherein the central portion is substantially flat and configured to substantially bear on the bearing surface of the mounting near a pivot between the long arm and the sash mounting plate at least in a closed position of the window stay.

12. The window stay of claim 11 wherein the elevation between the central portion and the offset portions decreases towards an end of the arm.

13. The window stay of claim 11 wherein the central portion is an elongate strip.

14. The window stay of claim 11 , wherein the offset portions are ribs angled at between 40 to 50 degrees relative to a plane of the arm.

15. The window stay of claim 11 , including:

a short arm including apertures to couple by pivots at each end to the frame mounting plate and a sash mounting plate of the window stay;

wherein the long arm includes apertures to couple by pivots at each end to the frame mounting plate and sash mounting plate; and

wherein the window stay further includes a washer integrally moulded onto one or more of the apertures.

16. The window stay of claim 15 wherein the apertures are shaped to retain the washers relative to the arms.

17. The window stay of claim 15 wherein the apertures include protrusions which retain the washers relative to the arms.