GB2359851A - Window locks - Google Patents

Description

2359851 IMPROVEMENTS IN OR RELATING TO WINDOWS The present invention

provides improvements in or relating to windows. Specifically, it offers improved security and flexibility in use for espagnolette locks whilst simultaneously offering a potentially more reliable and visually appealing design.

Espagnolette locks typically comprise a pin extending outwardly of the window sash frame and moveable transversely in the plane of the window. A Ushaped recess is provided on the outer frame, aligned with the direction of movement. The pin is then moved, by operation of a handle on the window, into and out of the U-recess. When in the recess, the pin prevents the window from opening. When the pin is moved out of the recess, the window can be opened.

Most locking pins are cylindrical, locating in a recess formed in the associated striker. Many now however incorporate an oversize head (referred to as a mushroom head) which locates below the striker, usually of metal plate. This provides retention in the axial direction of the pin, improving security. However, the mushroom head lengthens the pin, thus raising the possibility of interference with the outer frame or with the striker, for example as a sash is moved to its closed position.

The present invention therefore provides a lock for a window comprising one part with an elongate pin and another part comprising a striker plate, the striker plate having an aperture into which the pin extends when the lock is set, the exterior faces of the pin level with the aperture having a radially widening crosssection level with the aperture.

The radially widening cross-section of the pin can be provided in the form of a pin which tapers toward the one part.

Alternatively, or in addition, the radial widening can be by way of ridges on the exterior faces of the pin. These preferably co-operate with corresponding ridges on the interior faces of the aperture. These ridges on the pin can be formed most straightforwardly by providing a screw thread thereon. However, the principal aim is to secure the pin against axial movement by interengagement with the faces of the striker within the aperture. A series of parallel ridges is therefore also suitable, although potentially more difficult to form.

The aperture in the striker can be a U-shape, extending to one edge thereof, such that the pin can enter and leave the aperture by a simple transverse movement.

An embodiment of the present invention will now be described by way of example, with reference to the accompanying figures, in which; Figure 1 is a transverse cross-section through a locking mechanism according to a first embodiment of the present invention; Figure 2 is a plan view of the striker and pin of figure 1 Figure 3 is an enlarged view of the striker and pin of figure 1; Figure 4 is a transverse cross-section of a second embodiment; and Figure 5 is a plan view of the striker and pin of figure 4.

Referring to figures 1 to 3 an outerframe 10 surrounds a window sash frame 12. A glazing sealed unit 14 is held within the window sash frame 12. A handle 16 is provided on the window sash frame 12 and is operable so as to lock the window sash frame 12 within the outer frame 10.

This locking action is achieved by an espagnolette gearbox mechanism 18 provided within a side wall of the window sash frame 12. This gearbox mechanism 18 controls a pin 20 which extends outwardly of the window sash frame 12 towards the outer frame 10. Under control of the handle 16, the pin 20 is moved sideways, ie. into and out of the plate as shown in figure 1 and, in practice, parallel with the edge of the window sash frame 12.

A striker plate 22 is provided on an inwardly directed face of the outer frame 10, generally opposite the pin 20. The striker plate 22, as more clearly visible in figure 2, comprises a series of U-shaped apertures 24 which extend to one edge. As the pin 20 moves sideways, it moves into and out of the U-shaped apertures 24.

Thus, when in an open position the pin 20 lies outside of an aperture 24 and the window sash frame 12 can be opened relative to the outer frame 10. Whenthe gearbox mechanism is in the locked position, the pin 20 lies within an aperture 24 and thus the edge of the window sash f rame 12 cannot move away from the outer frame 10 transverse to the orientation of the U-shaped aperture 24 and the window is locked.

To provide additional security, pins such as that illustrated at 20 are often provided with an oversized head, referred to as a "mushroom" head. As the pin 20 moves into the aperture 24, the mushroom head locates beneath the striker plate 22 and thus prevents the pin 20 from being withdrawn, for example through deliberate distortion or displacement of the window. This provides additional security, but provides a larger projection from the edge of the window sash frame 12 which can in certain circumstances foul parts of the outer frame 10.

As particularly apparentfrom figure 3, the exterior cylindrical faces of the pin 20 are threaded and thus include a series of ridges such as that shown at 26. In like fashion, the interior faces 28 of the U-shaped apertures 24 are grooved to provided corresponding ridges therebetween which engage with the screw thread 26 of the pin 20. Thus, the pin 20 is constrained against longitudinal movement in the same manner as through an oversized mushroom head, but without the penalty of excessive length.

It is of course not necessary for the pin 20 to be provided with a helical screw thread as such, a series of parallel ridges being equally practical. Depending on the particular manufacturing circumstances and materials employed, one or other may be more convenient.

Referring to figures 4 and 5, the second embodiment of this invention is generally similar, and likewise involves an outer frame 110 surrounding a window sash frame 112 with a glazing sealed unit 114 held therewithin. Again, a handle 116 is provided on the window sash frame 112 to operate the gearbox mechanism 118.

In this embodiment, the pin 120 tapers, the thinnest part being closest the gearbox mechanism 118. Thus, the side furthest from the window sash frame 112 is wider than the aperture, beneath which it lies when locked. It is a simple matter to adjust the longitudinal position of the pin 120 so as to provide only a small clearance, in which case the length of pin projecting beneath the striker plate will be significantly less than that of a mushroom head.

This arrangement reduces the necessary length of the pin 20 or 120 and therefore reduces clearance difficulties between it and the outer frame. This yields benefits in the reliability of the window locking mechanism and eases tolerances in the clearance between the window sash frame 12 or 120 and the outer frame 10 or 110.

It will of course be understood that many variations are possible to the above-described embodiment without departing from the scope of the present invention.

Claims (8)

1 A lock for a window comprising one part with an elongate pin and another part comprising a striker plate, the striker plate having an aperture into which the pin extends when the lock is set, the exterior faces of the pin level with the aperture having a radially widening cross-section level with the aperture.

2.

A lock according to claim 1 in which the radially widening cross-section of the pin is provided by a pin which tapers toward the one part.

3.

A lock according to claim 1 or claim 2 in which the radial widening is provided by way of ridges on the exterior faces of the pin.

4.

A lock according to claim 3 in which the ridges co-operate with corresponding ridges on the interior faces of the aperture.

5.

A lock according to claim 4 in which the ridges on the pin are formed by providing a screw thread thereon.

6.

A lock according to claim 4 in which the ridges on the pin are parallel.

7.

A lock according to any one of the preceding claims in which the aperture in the striker is a U-shape.

8.

A lock for a window substantially as described herein with reference to andlor as illustrated in the accompanying figures.