GB2147046A - Lockable window fastener - Google Patents

Abstract

The window fastener comprises a base part 11 and a handle part 12 having a lug for engaging in the associated window frame. A key-operated locking mechanism 15 is provided to lock the handle part 12 to the base part 11 in the engaged position. The mechanism 15 comprises a locking pin 20 mounted within a bore 16 by means of a body 21, which has a cam surface 27 for engaging a cam follower 28. Rotation of the body by a key causes axial movement of the body and hence the locking pin 20. <IMAGE>

Description

SPECIFICATION Window fastener This invention relates to window fasteners.

With the substantial increase in burglaries from domestic properties and the declining detection rate, there has been a considerable demand for locking devices for windows. The majority have comprised additional mechanisi for attachment to existing window furniture and are hence rather unsightly. Attempts have been made to incorporate locks into the window fasteners themselves, but to date the results are unsatisfactory. For example, one proposal is to provide a locking screw which can be projected into an aperture in the base part of the window fastener, from the handle part, by rotation of an allen key, which engages its upper end. These have two significant disadvantages. First a considerabie number of rotations are required to achieve a satisfactory lock and therefore house occupiers only tend to use them when they are going away for a long time.As many burglaries are committed when the occupier has just "popped out" or is even inside the house, this is unsatisfactory. Secondly, allan keys are readily available and so a burglar can easily equip himself to open such locks rendering them virtually useless.

It is an object of the present invention to provide a locking mechanism which can be more readily locked and/or a fastener which could be less easily opened by a burglar.

From one aspect the invention consists in a window fastener comprising a base part, a handle part having a lug for engaging a window frame or a retaining device thereon and being pivotally mounted on the base part for movement between engaged and unengaged positions, the base part having an opening for receiving a locking element, and the handle part having a key-operated device for moving the element into or out of the opening when the handle is in the engaged position.

Preferably the element is moved between its withdrawn and lock positions by a rotation of the key of less than 360 and in a particularly preferred embodiment the key-operated device is mounted in a bore or recess in the handle part and comprises a body rotatably mounted in the bore, for carrying the locking element and resilient means for urging the body into a first position in which the element is withdrawn from the opening, one of the body and handle parts being formed with a cam or the like whereby rotation of the body in one sense drives the body against the action of the resilient means to cause the pin to lock in the opening.

The body may be formed with a cam surface and the handle with a cam follower projecting into the bore. The body may further be formed with slots or formations for receiving projections on a key, which slots may face axially with respect to the axis of rotation of the body.

The body may be formed with an axially extending ward which may be constituted by a part of the locking element. Additionally, or alternatively, the bore may be provided with a lateral ward. In any of these cases the bore may have a key-entry slot aligned with the body and the handle and base part may be provided with interengaging formations for locating the handle part in the engaged position such that the locking element is aligned with the opening.

The locking element may be a pin and the base part may have fixing holes, in which case trims may be provided to cover those holes.

The invention may be performed in various ways and a specific embodiment will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a window fastener according to the invention; Figure 2 is a longitudinal sectional view through the fastener of Figure 1; Figure 3 is a side view of the body of the key-operated device of the fastener of Figure 1; Figure 4 shows the developed cam form of the body of Figure 3; Figure 5 is an underneath view of the lug end of the handle of the fastener of Figure 1; and Figure 6 is a plan view of a key (not to scale) for use with the window fastener of Figure 1.

A window fastener 10 as shown in Figures 1 and 2 and comprises a base part 11, for attachment to a window and a handle part 1 2 having a lug 1 3 for engaging in the associated window frame or in a retaining device (not shown) thereon. The handle part 1 2 is pivotally mounted on the base part 11, by means of a stub axle, so that the lug 1 3 can be engaged or disengaged from the window frame. The position of the handle part 12, relative to the base part 11, shown in the Figures is the engaged position of the lug 1 3.

A key-operated locking mechanism 1 5 is provided to lock the handle part 1 2 to the base part 11 when the handle part 1 2 is in the engaged position.

The locking mechanism 1 5 is located in a bore 16 in the handle part 1 2. The upper end of the bore 1 6 is closed by a cap 1 7 which defines a key slot 1 8 whilst the lower end is closed by an annular base plate 19. A locking pin 20 is mounted within the bore by means of a body 21 for slidable movement within the bore 19, such that the locking pin 20 can be inserted into and withdrawn from an aperture 22 in the base part 11.

The body 21 has a narrowed !ower portion 23 which defines an annular space 24, with the bore,for receiving a compression spring 25 which acts between the base plate 1 9 and an annular seat 26 formed on the body. The spring thus acts in a sense to move the body 21 upwardly within the bore 19. One side of the body is formed with a cam surface 27 (which can best be seen in Figures 3 and 4) which engages a projecting cam follower 28 formed in the side of the bore 1 9.

The upper end 29 of the body is formed with an axially upwardly facing slot 30 which is divided into two portions by the upper part 31 of the locking pin 20.

When it is desired to lock the handle part 1 2 to the base part 11 ,a key 32 (see Figure 6) is introduced through the key slot 18 into the slots 30 on the body 21. It will be noted that the key 32 has a central cut-out 33 which bridges the tipper part 31 of the locking pin.The locking pin therefore serves as a ward to prevent engagement of the body 21 by a screwdriver or the like.

When the key 32 is rotated it engages the body 21 and the resultant rotation of the body 21 causes it, and hence the locking pin 20, to move downwardly, against the action of the spring 25, as the cam follower 28 moves up the cam surface 27 into the final recessed portion 34 in which the body 21 is held in the position shown in Figure 2.

In this position the locking pin is fully inserted in the aperture 22 and the handle part 11 and base part 1 2 are held against relative rotation. The fastener can therefore not be undone. When it is desired to unlock the fastener the key is again inserted and rotated in the opposite sense, with an associated slight depression of the body, so that the cam follower 28 leaves the recess 34 and the body 21 moves upwardly under the action of the spring 25. The locking pin 20 is hence withdrawn from the aperture 22.

It will be appreciated that the mechanism described above provides a good positive lock, which can be engaged by a simple twist of a key of less than 360 and preferably of between 120 and 1 50,. It is therefore possible for an occupier to instantly lock his window fasteners in no more time than it takes to lock his front door. Further the lock is not operable by any standard tool such as an allen key and hence is substantially more burglar proof than existing arrangements. The lock could be made more secure by adding further wards, for example, lateral annular wards in the bore 19.

To ensure easy engagement of the locking mechanism 15, the handle part 11 is provided with a notch 36 between the axle 14 and locking mechanism 1 5 (see Figure 5) which locates against a corresponding projection (not shown) on the base part 11 when the pin 20 and aperture 22 are aligned.

A further improvement of this fastener is the provision of trims 37 over the locating screw holes 38 of the base part 11. These not only improve the appearance of the base part, but also limit the access of a burglar to those screws and hence help prevent the removal of the fastener. Indeed it is envisaged that the trims 38 could be glued to the base part 11 after installation, to improve security.

It will be appreciated that the locking mechanism 1 5 described above may have uses in many other applications where axial movement of the locking rim is required and hence the invention also consists in a locking mechanism comprising a body for carrying a locking element locatable in a bore of a member which is to be locked to another and having a cam or the like engaging a part of a bore whereby rotation of the body in one sense moves the body axially in the bore to provide locking movement of the locking element.

It will be appreciated that instead of the cam surface and cam follower described above any other suitable construction could be used, for example, a pin on the 5 body could run within a suitably shaped slot in the bore wall.

The invention also consists in a key-operated locking mechanism having an elongate locking element and means for moving the locking element axially in response to a single rotation or less of a key.

It is to be understood that although certain aspects of the invention have been defined above, the invention also includes any other inventive combination of the features set out either in those definitions of invention or in the device specifically described. Whilst the main object of the invention has been described, it is to be understood that the invention can include devices which do not fulfil that object.

Claims (14)

1. A window fastener comprising a base part, a handle part having a lug for engaging a window frame or a retaining device thereon and being pivotally mounted on the base part for movement between engaged and unengaged positions, the base part having an opening for receiving a locking element, and the handle part having a key--operated device for moving the element into or out of the opening when the handle is in the engaged position

2. A fastener as claimed in claim 1 wherein the element is moved between its withdrawn and locked positions by a rotation of the key of less than 360".

3. A fastener as claimed in claim 1 or claim 2 wherein the key-operated device is mounted in a bore or recess in the handle part and comprises a body rotatably mounted in the bore, for carrying the locking element and resilient means for urging the body into a first position in which the element is withdrawn from the opening, one of the body and handle parts being formed with a cam or the like whereby rotation of the body in one sense drives the body against the action of the resilient means to cause the pin to lock in the opening.

4. A fastener as claimed in claim 3 wherein the body is formed with a cam surface and the handle is the cam follower projecting into the bore.

5. A fastener as claimed in claim 3 and claim 4 wherein the body is formed with slots or formations for receiving projections on a key.

6. A fastener as claimed in any one of claims 3 to 5 wherein the slots face axially with respect to the axis of rotation of the body.

7. A fastener as claimed in any one of claims 3 to 6 wherein the body is provided with an axially extending ward.

8. A fastener as claimed in claim 7 where a part of the locking element constitutes the axially extending ward.

9. A fastener as claimed in any one of the preceeding claims wherein the bore is provided with a lateral ward.

10. A fastener as claimed in any one of claims 3 to 8 wherein the bore has a keyentry slot aligned with the body.

11. A fastener as claimed in any one of the preceeding claims where a handle and base part is provided with inter-engaging formations for locating the handle part in the engaged position such that the locking element is aligned with the opening.

1 2. A fastener as claimed in any one of the preceeding claims wherein the locking element is a pin.

1 3. A fastener as claimed in any one of the preceeding claims wherein the base part has fixing holes and further comprising trims to cover those holes.

14. A key-operated locking mechanism having a locking element and means for moving the locking element axially into and out of a locking position in response to a single rotation, or less, of a key.

1 5. A window fastener substantially as hereinbefore described with reference to the accompanying drawings.