GB2245641A

GB2245641A - Window fastening device

Info

Publication number: GB2245641A
Application number: GB9113247A
Authority: GB
Inventors: Philip James Burnley
Original assignee: OLDRIDGE LINDA JANE
Current assignee: OLDRIDGE LINDA JANE
Priority date: 1990-06-27
Filing date: 1991-06-19
Publication date: 1992-01-08
Anticipated expiration: 2011-06-19
Also published as: GB2245641B; GB9014330D0; GB9113247D0

Abstract

A secondary locking arrangement for a plastics material framed window having a primary espagnolette-type locking arrangement 16 of posts 18 mounted on a slider engaging with corresponding channels is provided which comprises an additional detent 24 operable by the same means 14 which operates the primary lock whereby to engage in a corresponding slot in the frame. The degree of engagement of the detent within the slot is greater than that of the posts within the channels of the primary locking system. This ensures that the secondary detent is not capable of being removed from its corresponding slot by a degree of flexion of the frame which would "spring" the posts from their respective channels. <IMAGE>

Description

"WINDOW LOCK" This invention relates to a window lock and especially to a lock for use with pve double glazed windows.

Traditionally windows for houses and other buildings were largely made from timber. The advent of modern plastics materials such as Upvc has resulted in a number of windows, especially double glazed windows, being made from Upvc moulded frames which have the advantage of being virtually rot proof and maintenance free compared to their timber counterparts. While the opening and closing mechanisms of such windows vary, a common mechanism includes a handle keyed through a gear arrangement to a slider which moves a pair of posts into and out of registration with channel members fixed on the frame. By this means the window can be secured from the interior against opening from outside.

However, unless the window has been properly fitted there is often sufficient flexability in the pvc frame to allow a lever to be inserted and to "spring" the posts out of their respective channels thus allowing the window to be opened from the outside without breaking the glazing unit.

The invention seeks to provide a rocking arrangement which overcomes or reduces the above disadvantage.

According to the present invention there is provided a secondary locking arrangement for a plastics material framed window having a primary locking arrangement of posts mounted on a slider engaging with corresponding channels, which comprises of additional detent operable by the same means which operates the primary lock whereby to engage in a corresponding slot in the frame, in which the degree of engagement of the detent within the slot is greater than that of the posts within the channels of the primary locking system.

Owing to the construction of many Upvc double glazed systems a six millimeter clearance is left around the glazing unit in order to adequately drain condensed moisture. Unless packing is placed within this gap at points corresponding to the locking posts and channels which is usually not the case), insertion of a jemmy or other lever allows the frame surrounding the glazed unit to be deflected, without breaking the glazing unit, a sufficient amount to "spring" the posts from their respective channels. In accordance with the invention the secondary detent is of greater extent and is not capable of being removed from its corresponding slot by this degree of flexion of the frame.

The detent may take the form of, for example, a metal plate, and may be mounted on the spindle of the operating handle of the primary locking system. This operation of the primary locking system automatically brings the detent of the invention into engagement with its corresponding slot. Alternatively, other equivalent arrangements may be employed, for example a hook like detent engaging with a suitable bar or pillar within the frame.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is this partial diagrammatic exploded view of a window handle and primary locking system with a detent in accordance with the invention; Figure 2 is a side view corresponding to figure 1; Figures 3A and B are end views corresponding to Figure 1 illustrating the open and closed positions.

Referring to the drawings, and in particular Figure 1, the handle and primary locking system for a Upvc casement window is illustrated, but it will be appreciated that the invention is equally applicable to a pvc door, patio door or the like. The primary locking system comprises handle 10 on a mounting block 12 having a square spindle 14 which engages a mechanism 16 including a gear and slider arrangement (not shown) to move a pair of posts 18 within cutouts 20 of a lock bar 22. This form of primary locking system is commonly employed with windows of this type. In accordance with the invention, a detent in the form of a metal plate 24 having a offset orifice 26 for receiving the spindle 14 is mounted as illustrated in Figure 2 behind the locking plate 22.Not shown in the drawings is a corresponding slot formed in the adjacent window frame capable of receiving the free end 28 of the plate 24. The operation of the device may best be seen from Figure 3. If the handle is turned to the locking position the posts 18 move downwardly (as viewed in Figure 3) to engage with corresponding channel members (not shown) mounted on the window frame assembly in the manner conventionally known.

However, in accordance with the invention, additionally the detent 24 moves to the position illustrated in Figure 3A where it engages in the slot formed in the frame to receive it. As can also be seen from Figure 3A the extent of the free end of 28 of the detent 24 is considerably greater than that of the post 18 and thus an amount of bending or jemmying of the window frame which would free the post 18 from its corresponding channel would not release the detent 24 from its slot. Opening the window is a reversal of this operation as illustrated in Figure 3B where the detent swings back within the frame of the window casement.

Additionally or alternatively, a second detent 24A (shown ghosted in Figure 1) may be fitted on the spindle 14 on the opposite side of the mechanism 16. This operates in the same manner but owing to the different displacement along the spindle allows the window to be opened a few degrees before it engages in the slot. By this means a " night venting" position may be attained where the window is nevertheless locked although opened a small amount to admit air. When fitted in this position the detent 24A preferably includes a cut out portion 30 to avoid fouling the screw 32 holding the block 12 to the mechanism 16.

While the invention has been inscribed with reference to the detent being driven off an existing drive it could be driven from a separate or additional drive. There can be more than one detent per drive and indeed it could be a simple key operated cylinder as a separate defence against the window being opened. Furthermore while the above embodiment shows the detent mounted on the casement frame to operate into the fixed frame it will be appreciated that the device would work equally well mounted the other way round.

The invention thus provides a simple and affective solution to the problem of the forcing open of pvc windows.

Claims

1. A secondary locking arrangement for a plastics material framed window having a primary locking arrangement of posts mounted on a slider engaging with corresponding channels, which comprises an additional detent operable by the same means which operates the primary lock whereby to engage in a corresponding slot in the frame, in which the degree of engagement of the detent within the slot is greater than of the posts within the channels of the primary locking system.

2. An arrangement as claimed in claim 1 in which the detent is in the form of a metal plate and is mounted on the spindle of the operating handle of the primary locking system.

3. An arrangement as claimed in claim 1 in which a hook like detent is arranged to engage witha suitable bar or pillar within the frame.

4. An arrangement as claimed in either of claims 1 or 2 in which the detent is in the form of a plate having an orifice offset with respect to the centre of the plate for mounting on the spindle of the primary locking means leaving a free end for co-operation with the corresponding slot in the window frame.

5. An arrangement as claimed in claim 4 in which the free end is of sufficient extent to resist being removed from its corresponding slot irrespective of distortion of the window frame.

6. An arrangement as claimed in any of claims 1 - 5 in which a second detent is fitted on to the spindle of the primary locking means displaced from the first detent allowing the window to be opened a few degrees but still effectively locked.

7. A secondary locking arrangement substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.