GB2270537A

GB2270537A - Lock

Info

Publication number: GB2270537A
Application number: GB9316773A
Authority: GB
Inventors: Ian Alexander Gordon
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-08-12
Filing date: 1993-08-11
Publication date: 1994-03-16
Anticipated expiration: 2013-08-11
Also published as: GB9316773D0; GB2270537B; GB9217074D0

Abstract

A lock assembly comprises a latch (10) which latch comprises a shank receiving portion (11) engageable with the shank of the handle used to operate a window. The latch (10) also comprises a hook portion (12) engageable in a first latch receiving portion (13) mountable on an outer frame in which the window is hingably mountable. The first latch receiving portion (13) comprises a first aperture (14) and a second aperture (15). The hook portion (12) is engageable in the first aperture. Further movement of the handle of the window causes the hook portion to engage in the second aperture (15). If an attempt is made to prise the window out of the outer frame, and end portion (17) of the hook bears down on the surface (18) of the second aperture (15) thus reinforcing a lock effect of the latch (10). <IMAGE>

Description

LOCK ASSEMBLY This invention relates to a lock assembly for locking a door or window securely in place in an outer frame, and particularly, but not exclusively to a lock assembly for securely locking a window or door formed from UPVC, in position in an outer frame.

UPVC windows typically comprise a double glazed unit packed within a UPVC frame. The window is hingably mounted within an outer UPVC frame.

The window may be locked in a closed position by means of, for example, a deadlock. In addition, espagniolettes formed in the window frame and locatable in the outer frame, provide added security. The espagniolettes are positioned within the window frame, when the window is in an open position. Movement of the window handle to close the window results in the espagniolettes being activated, and extending from the window frame into holes positioned in the outer frame, where they are locatable in order to add extra security to the window.

Despite the presence of locks and espagniolettes, it is well known that it is relatively easy for an unauthorised intruder, who wishes to gain access to a building to open a door or window.

Typically, an intruder will use a screwdriver or other similar tool, in order to prise the window out of the outer frame, thus gaining access to the building.

It is possible to prise the window from the frame due to the fact that the UPVC frame is deformable. In addition, the glazed unit within the window is often not correctly packed within the frame, and this results in added deformability.

According to a first aspect of the invention there is provided a lock assembly for a window comprising: a handle mounted on a shank and operable to open and close the window within an outer frame; and a latch mechanism comprising: a latch having a shank engaging portion, and a hook portion; a latch receiving portion formed in the outer frame, which latch receiving portion comprises a first aperture through which the latch is moveable on operation of the handle, and a second aperture with which the hook is engageable, wherein movement of the window away from the outer frame in the vicinity of the latch enhances the engagement of the hook in the second aperture.

The latch, being connected to the shank of the handle is moveable when the handle is moved. When the handle is moved into an open position in which the window is open in the outer frame, the latch is positioned within the frame of the window.

When the handle is moved, in order to close the window the movement of the shank causes the hook portion to move out of the window frame and into the outer frame, via the latch receiving portion. The latch will first of all pass through the first aperture of the latch receiving portion, and then further movement of the handle causes the hook portion of the latch to engage in the second aperture of the latch receiving portion.

The combination of the hook shape of the latch and the first and second apertures, means that if an attempt is made to prise the window out of the outer frame, the hook portion of the latch bears down on a surface of the second aperture and increases the strength of the lock.

Previously, a known latch has comprised a simple tongue shape.

Such a latch may easily be prised out of the latch receiving portion, as there is nothing to resist movement of the window away from the outer frame, such as happens when an unauthorised person attempts to prise open the window.

In the lock according to the present invention, such movement of the window frame causes the hook to be more securely engaged in the latch receiving portion.

Conveniently, the latch receiving portion is formed from metal.

Alternatively, the latch receiving portion is formed from a plastics material.

Preferably, the latch receiving portion is encased in a box, which is mounted in the outer frame of the window. The presence of the box reduces the chances that the metal frame from which the latch receiving portion is formed, will rust.

Advantageously, the width of the first aperture increases from a first end positioned near to the second aperture, to a second end remote from the second aperture.

When the latch first enters the first aperture on movement of the handle, it will enter towards the second end of the first aperture. The fact that the width of the aperture towards this end is greater than at the opposite end, means that the latch may enter the aperture even if the window is still in a slightly open position. Further movement of the handle into the closed position will cause the latch to move towards the second end of the first aperture. As the latch so moves, the narrowing width of the first aperture will have the effect of pulling the window into a closed position.

The latch may comprise a substantially right angle bend, between the shank engaging portion and the hook portion. This allows the hook portion to engage in a latch receiving portion, mounted on the outer frame rather than formed in the outer frame.

According to a second aspect of the invention there is provided a window comprising a lock assembly according to the first aspect of the invention.

Preferably the window further comprises a second latch receiving portion positioned such that when the latch is engaged in the second latch receiving portion, the window is maintained in a slightly open position.

The second latch receiving portion is thus useful to allow a certain degree of security whilst maintaining the window in an open position. This may be desirable, for example, at night particularly in bedrooms.

The invention will now be further described by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic representation of the latch according to the present invention with the window frame partially cut away; Figure 2 is a schematic representation of the latch forming part of the lock assembly according to the present invention; Figure 3 is a more detailed representation of the latch shown in Figure 2; Figure 4 is a more detailed representation of the latch receiving portion shown in Figure 2; Figures 5a to 5c are more detailed representations of the box forming part of the latch receiving portion shown in Figure 2; Figures 6a and 6b are schematic representations of the box in which the latch receiving mechanism is positionable;; Figures 7a to 7c are schematic representations of a second latch receiving mechanism showing the second latch receiving mechanism.

Figure 8 is a schematic representation of a window according to the present invention showing the second latch receiving mechanism.

Referring to figures 1 to 8, a lock assembly according to the present invention comprises a latch 10. The latch 10 comprises a shank receiving portion 11. The shank receiving portion 11 is engageable on the shank of a handle 80 used to operate a window 81 to which the latch mechanism is to be incorporated.

The latch 10 also comprises a hook portion 12 at an opposite end to the shank receiving portion 11. The hook portion 12 is engageable in a first latch receiving portion or keep 13 which is mounted in an outer frame 82, in which the window 81 is hingeably mountable. The first latch receiving portion 13 comprises a first aperture 14 and a second aperture 15.

The latch receiving portion 13 is positionable within a box 16 which is mounted in the outer frame 82.

Referring to Figure 1, in use, when the handle 80 of the window 81 is positioned in an open position, the latch 10 is concealed within the window frame 83. When the handle 80, and thus the shank, are moved in order to close and lock the window 81, the movement of the shank causes the latch 10 to move in a substantially circular manner about the shank. The latch 10 thus enters the first aperture 14. Further movement of the handle causes the hook portion to engage in the second aperture 15 such that an end portion 17 of the hook portion 12, protrudes through the second aperture 15. The shape of the hook portion 12 in conjunction with the second aperture 15 means that if an attempt is made to prise the window out of the outer frame, the end portion 17 of the hook bears down on the surface 18 of the second aperture 15, thus reinforcing the lock effect of the latch 10.

The width of the first aperture narrows towards the end of the first aperture positioned nearest the second aperture. This means that it is possible to engage the latch in the first aperture when the window is not quite closed. Further movement of the handle to the closed position moves the latch towards the narrow end of the first aperture. This has the effect of drawing the window closed.

Referring to Figures 7a to 7e, a second latch receiving mechanism or keep is designated generally by the reference numeral 70. The keep 70 serves as a night vent keep, and allows the window to be held in a slightly open position with a certain amount of security. This may be particularly advantageous, for example, in bedroom windows when it is desired to have some ventilation in the bedroom during the night.

Referring to Figure 8, a window according to a second aspect of the invention comprising a latch mechanism according to a first aspect of the invention is shown schematically.

Figures 9 and 10 illustrate a second embodiment of the invention in which the latch 50 is formed with a substantially right angled bend. This allows the latch receiving portion 51 to be mounted on, rather than in the outer frame.

Although the invention has been described in the terms of a window, it is to be understood that the invention is equally applicable to doors of all kinds, including patio doors as well as windows. The term "window" is therefore to be construed as including a door, patio door or the like. In addition, although the invention has been described predominantly in terms of UPVC windows and doors, it is to be understood that the invention is equally applicable to doors and windows made from any suitable material, for example, wood.

Claims

1. A lock assembly for a window comprising: a handle mounted on a shank and operable to open and close the window within an outer frame; and a latch mechanism comprising; a latch having a shank engaging portion, and a hook portion; a latch receiving portion formed in the outer frame, which latch receiving portion comprises a first aperture through which the latch is moveable on operation of the handle, and a second aperture with which the hook is engageable, wherein movement of the window away from the outer frame in the vicinity of the latch enhances the engagement of the hook in the second aperture.

2. A lock assembly according to claim 1 wherein the latch receiving portion is formed from a plastics material.

3. A lock assembly according to claim 1 or claim 2 wherein the latch receiving portion is encased in a box mountable in the outer frame of the window.

4. A lock assembly according to any one of the preceding claims wherein the width of the first aperture increases from a first end positioned near to the second aperture to a second end remote from the second aperture.

5. A lock mechanism according to any one of the -preceding claims wherein the latch comprises a substantially right angled bend, between the shank engaging portion and the hook portion.

6. A window comprising a window frame, and positionable within an outer frame, which window comprises a lock assembly according to any one of claims 1 to 5.

7. A window according to claim 6 further comprising a second latch receiving portion positionable such that when the latch is received within the second latch receiving portion, the window is held in a slightly open position.

8. A lock assembly substantially as hereinbefore described with reference to the accompanying drawings.

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