GB2346929A

GB2346929A - A resiliently biassed keeper or retainer for a window closure

Info

Publication number: GB2346929A
Application number: GB9927070A
Authority: GB
Inventors: Terence James Dolman
Original assignee: Trojan Hardware and Design Ltd
Current assignee: Trojan Hardware and Design Ltd
Priority date: 1998-11-19
Filing date: 1999-11-17
Publication date: 2000-08-23
Anticipated expiration: 2019-11-17
Also published as: GB2346929B; GB9927070D0; GB9825236D0

Abstract

A lock assembly 100, for use in combination with a movable frame 6, is pivotable within a fixed frame 5 between an open position and a closed position. The lock 100 comprises a retainer 200 which is mounted to an inner surface of a fixed frame 5 and has at least one cut-out 201, 202. The lock 100 also comprises latch means 600 which is secured to the movable frame 6 and can be moved to engage the cut outs 201, 202 of the retainer 200. The retainer 200 is movable relative to the inner surface of the fixed frame 5 and a biasing means 500 urges the retainer 200 away from the fixed frame 5. As the movable frame 6 moves to the closed position, the movable frame 6 moves the retainer 200 against the biasing means 500 to a predetermined position where the cut-out 201, 202 is automatically in correct alignment and the latch member 601 can enter the keeper. Preferably the retainer 200 is of rectangular shape and is formed by pressing, forging or stamping. The latch member 601 may have a mushroom head and the biasing means 500 may be a resilient foam pad.

Description

IMPROVEMENTS IN LOCK ASSEMBLIES This invention relates to improvements in lock assemblies, in particular lock assemblies for locking a member movable relative to a frame in a closed position. The movable member may be a window or door.

One particular type of window assembly comprises a fixed main frame of rectangular outline with a cross-bar or transom bisecting the frame horizontally. The lower half of the fixed frame is glazed whilst the upper half of the frame above the transom is free of glazing and accommodates a movable member adapted to pivot outwards about a horizontal axis at the top of the frame so that the window can be opened for ventilation.

There is a trend with such window designs to make the window assembly appear to resemble, at least from a distance, a sash window. For this to be achieved, it is important for the transom to be of a reduced depth.

Whilst the provision of a slim transom is aesthetically pleasing, it does render standard locking assemblies impractical. In a standard assembly, a keeper plate is fixed onto an upper face of the transom above a recess formed in the transom. A latch member is then provided on a lower face of the movable frame so that when the window is closed, the latch member is moved downwards and across into the recess, and behind the keeper plate. Obviously, the deeper the recess and larger the latch member the stronger the lock assembly.

With a shallow transom, there may not be sufficient room to provide a recess of any substantial depth. Furthermore, because of the need to provide sealing of the window, the gap between the movable face and the transom may be quite small, which presents further difficulties in accommodating the locking assembly, and in particular in ensuring that the latch member and keeper engage properly. It is beneficial for the lock assembly to be accommodated within this gap where it is shielded from outside, to prevent forced entry.

In accordance with a first aspect, the invention provides a lock assembly for use in combination with a movable frame pivotable within a fixed frame between an open position and a closed position, the lock assembly comprising a retaining member adapted to be mounted to an inner face of the fixed frame and defining a keep having at least one cut-out, and a latch means adapted to be secured to the movable frame and having at least one latch member adapted to co-operate with the cut-out, the retaining member being movable relative to the inner face of the fixed frame with biassing means urging the retaining member away from the fixed frame, the arrangement being such that movement of the movable frame into the closed position moves the retaining member against the biassing means into a predetermined position in which the latch member can be moved into engagement with the keep.

By providing a retaining member defining a keep which moves relative to the fixed frame, the cut-out is automatically aligned correctly relative to the movable frame by the action of the biassing means which presses the retaining member towards the movable frame. Even if the spacing between the movable frame and fixed frame is varied, the retaining member will still be biassed into the correct position relative to the movable frame. This is especially advantageous where a slim fixed frame is used which cannot accommodate a standard recess for a fixed keep plate. It will, however, be appreciated that the lock assembly is suitable for use with a wide variety of types of window and doors in which a member moves relative to a fixed frame The retaining member may be of metal, and comprise a pressing or forging or stamping having a substantially rectangular shape. Two cut-outs may be provided, each one extending inwardly from near to one end of a respective side of the retaining member. Each cut-out is, in use, adapted to receive a mushroom headed latch member provided on the movable frame, with the stem of the latch member being between the sides of the cut-out and the head being between the underside of the retaining member and the fixed frame. The width of each cut-out can be chosen so the respective latch member can only be released by sliding the mushroom headed portion out from the sides of the cut-out substantially parallel to the inner face of the fixed frame.

An attachment member may be provided which is adapted to support the retaining member relative to the fixed frame. A portion of the retaining member may be trapped or hooked between an underside of the attachment member and the inner face of the fixed frame.

A slotted opening may extend upwards from the bottom edge of the retaining member to define two spaced apart, parallel arm portions. The free ends of the arm portions may be trapped or hooked between the attachment member and the fixed frame as the only connection between the retaining member and the fixed frame.

The attachment member may be fixed to the frame by one or more, preferably two, screws or bolts. Preferably, the attachment member is adapted to pivotally support the retaining member relative to the fixed frame.

Preferably the retaining member is trapped in such a way that it can pivot about the ends of the arms (or thereabouts). Alternatively or additionally, the choice of material and thickness of the retaining member may be selected to provide a degree of resilience which allows movement of the retaining member.

The attachment member preferably is also metal, and may comprise a metal sheet pressing or casting. The attachment member may be substantially H-shaped with two end portions connected by a central crossmember. Alternatively, it may be T-shaped having just one end portion.

The retaining member may be trapped between one end portion of the attachment member and the frame. Two screws may extend through holes in the one end portion to secure the attachment means to the frame. As will be appreciated, the two arms of the retaining member then straddle the cross-member of the attachment member.

The biassing means may comprise a resilient member provided between the retaining member and the fixed frame. Most preferably, this comprises a resiliently compressible foam pad, stuck to the fixed frame.

As the retaining member is moved towards the fixed frame, the foam is compressed, which generates a biassing force.

The arm portions of the retaining member may define ramps along which the movable frame may slide to urge the retaining member gradually towards the predetermined position.

In accordance with a second aspect, the invention provides a window assembly comprising a movable frame which is adapted to move between an open and a closed position relative to a fixed frame, the window assembly incorporating a lock assembly according to the first aspect of the invention.

The window assembly may be of the top hung type, with the movable frame pivotally mounted at its top edge on the fixed frame, and with a lower edge engaging a horizontal transom of the fixed frame. The lock assemblyis preferably secured to the upper face of the transom so that when the window is closed the lock assembly is wholly or partially accommodated within a gap defined between the lower edge of the movable frame and the upper face of the transom.

The latch member is preferably a mushroom-headed latch member. The head of the latch member may be accommodated between the retaining member and the surface of the transom. In this way, no recess needs to be provided in the transom so a shallow transom can be provided.

Preferably, the window assembly is so constructed and arranged as to provide the appearance of a sash window when in the closed position.

There will now be described, by way of example only, one embodiment of the present invention with reference to the accompanying drawings of which: Figure 1 is a plan view of a window assembly which is adapted to have the appearance of a sash window; Figure 2 is a cross-sectional view of a lower portion of the movable frame and the transom of the fixed frame showing the location of a lock assembly in accordance with the invention; Figure 3 (a) is a plan view of the retaining member of the lock assembly which is shown in side elevation in Figure 3 (b); Figure 4 (a) is a plan view and (b) is a side elevational view of the attachment member of the lock assembly, an enlarged view of part of one end of the attachment member being shown in cross-section in Figure 4 (c).

Figure 1 is a cross-section through a portion of a window assembly 1 including a lock assembly according to the present invention.

The window assembly 1 comprises two window panes 2,3 received within a fixed frame 4 shaped to fit an aperture. For convenience, a rectangular frame is shown. The frame 4 is divided in half horizontally by a transom 5 and the lower half of the window assembly is glazed with a double 3.

The top half of the window assembly is adapted to be closed by a movable frame 6 having a shape complementary to the top half of the fixed frame 4. The movable frame 6 is also glazed. A hinge mechanism (not shown) supports the movable frame 6 relative to the frame 4 and allows the frame 6 to swing between an open position of the window and a closed position as shown in Figure 1.

A lock assembly 100 is provided in two parts. One part is fixed onto a lower edge of the movable frame 6. The other part is fixed on the upper face of the transom 5. One part of the lock assembly thus moves with the movable frame and engages with the other part fixed on to the transom when the window is closed and the lock assembly is moved to a locked position. The location of the lock assembly 100 is shown in detail in Figure 2.

Figure 2 is a cross-section through the lower edge portion of the movable frame 6 and the transom 5 of the fixed main frame. Each frame 5,6 is formed as a UPVC extrusion.

The transom 5 defines a channel 51 which faces downwards, and in which an upper edge of a double glazing panel is received. A wall portion 53 is defined upstanding along an upper inside edge of the transom 5, ie the edge on the side of the upper face of the transom which the movable frame opens away from. This wall 53 receives a sealing strip 54 which can engage the lower portion of the movable frame 6 to prevent draughts when the window is closed.

The lower edge portion of the movable frame defines an upwardly directed channel 61 which receives a double glazed window pane 62. A wall portion 63 depends from an outside edge of the lower portion and carries a sealing strip 64. This strip engages with an outer edge of the transom when the window is closed to prevent draughts and protect the lock mechanism.

The movable frame 6 is pivotally mounted relative to the fixed frame 4 so that when in its closed position there is a small clearance between the underside of the lower portion of the movable frame and the upper face of the transom 5.

The transom 5 supports a first part of the lock mechanism 100 comprising a retaining member 200 which is pivotally secured to an upper face of the transom 5 by an attachment plate 300. A pair of bolts or screws 400 pass through the attachment plate 300 into the transom 5 and an end portion of the retaining member 200 is trapped between the attachment plate 300 and the transom 5. The remainder of the retaining member 200 therefore defines a flap or tongue and can pivot relative to the transom 5. A foam pad 500 is provided between the free end of the retaining member 200 and the upper face of the transom 5. The pad 500 biases the free end away from the transom when the window is open. On closing of the window, the lower edge portion of the movable frame contacts the retaining member and pushes it towards the transom, simultaneously compressing the foam pad 500.

The bias provided by the foam pad 500 ensures that the free end of the retaining member is biassed into contact with a portion of the movable frame when closed. This ensures correct alignment of the retaining member with the movable frame in the event that warping or misalignment of the movable frame in the window causes changes in the height of the space between the transom and the movable frame.

The retaining member 200, as shown in more detail in Figure 3, is formed as a pressing from a planar metal sheet. The retaining member 200 comprises a substantially square shaped element with a cut-out 201,202 extending inwards from an upper portion of each side of the plate. Each cut-out 201,202 is adapted to accommodate a mushroom headed latch member provided on the movable frame. The end of the retaining member carrying the cut-outs thus defines a keep. An elongate slot 203 extends upwards from the base of the retaining member to define two spaced arms 204,205. The arms 204,205 are bent about one or more crease lines. The free ends 206,207 of the arms of the retaining member 200 are trapped onto the upper face of the transom 5 by the attachment member 300, and crease lines 207,208 209 are formed so that the portion of the retaining member 200 carrying the cut-outs 201,202 is spaced above the upper face of the transom 5. The retaining member 200 is slightly resilient.

The attachment member 300 is shown in Figure 4. It comprises a substantially H-shaped plate having two elongate spaced end portions 301, 302 linked by an elongate cross-piece 303. One end portion 302 of the attachment member is provided with two holes 304,305 spaced above the centre of the end portion by which it can be attached to the transom 5 by fixing screws through the holes.

The underside of the inwardly directed edges of the end portion 301 (one edge each side of the cross piece) are cut away as shown in Figure 3C.

When clamped to the upper surface of the transom 5, the transom and cutaway portion thereby define a recess into which the ends of the arms of the retaining member can be secured. The arrangement is such that the free end of the retaining member 200 points generally inwards towards the inside of the window aperture. Thus, as shown in Figure 2, the screws penetrate the upper face of the transom towards the outside of the window frame with the retaining member extending towards the inside of the window frame.

In use, when the window is open the lower portion of the movable frame is spaced from the transom. The foam pad biases the portion of the retaining member defining the cut-outs away from the transom. As the movable frame is moved to the closed positon, the underside of the frame engages with the retaining member arms 204, 205 and continued movement to the closed position forces the retaining member down towards the transom, and into a predetermined position.

When the window is fully closed, the retaining member is biassed into contact with the underside of the movable frame independent of the clearance between the movable frame and the transom. A locking latch means 600 comprising a pair of spaced mushroom headed latch members 601 mounted on the movable frame can then be moved into position within the keeper cut-outs 201,202. As the enlarged mushroom head portion engages beneath the cut-outs and above the transom face, this locks the window in its closed position.

To open the window, the latch members must first be moved out from the cut-outs in a direction substantially parallel to the plane of the window.

Movement of the latch members may be achieved by a handle (not shown) provided on the inside of the movable frame acting through one or more cams upon the latch member 601. Once clear from the cut-outs, the movable frame is free to move relative to the fixed frame.

Also shown in Figure 2 is a protrusion which depends from the underside of the lower portion of the movable frame. This protrusion is positioned so that it strikes a portion of the retaining member when the movable frame reaches the correct position for engaging the latch members with the keeper cut-outs. The protrusion also helps to prevent the retaining member from being levered out from under the attachment member by covering the interface between the attachment member and the retaining member when the window is closed.

By providing a retaining member defining a movable keep, the length of the latch member protruding from the movable frame can be minimised.

Since the keep is biassed into the correct position relative to the latch member, the risk of the latch member not engaging the keep is minimised.

Also, the overall spacing between the lower portion of the movable frame and the transom can be kept as small as possible.

Claims

CLAIMS 1. A lock assembly for use in combination with a movable frame pivotable within a fixed frame between an open position and closed position, the lock assembly comprising a retaining member adapted to be mounted to an inner face of the fixed frame and defining a keep having at least one cut-out, and a latch means adapted to be secured to the movable frame and having at least one latch member adapted to co-operate with the cut-out, the retaining member being moveable relative to the inner face of the fixed frame with biassing means urging the retaining member away from the fixed frame, the arrangement being such that movement of the movable frame into the closed position moves the retaining member against the biassing means into a predetermined position in which the latch member can be moved into engagement with the keep.
2. A lock assembly according to claim 1 in which the retaining member is of metal and comprises a pressing or forging or stamping having a substantially rectangular shape.
3. A lock assembly according to claim 1 or claim 2 in which two cut-outs are provided, each one extending inwardly from near to one end of a respective side of the retaining member.
4. A lock assembly according to any preceding claim in which the or each cut-out is, in use, adapted to receive a mushroom headed latch member provided on the movable frame, with the stem of the latch member being between the sides of the cut-out and the head being between the underside of the retaining member and the fixed frame.
5. A lock assembly according to any preceding claim in which an attachment member is provided which is adapted to support the retaining member relative to the fixed frame.
6. A lock assembly according to claim 5 in which a portion of the retaining member is trapped or hooked between an underside of the attachment member and the inner face of the fixed frame.
7. A locking assembly according to claim 5 or claim 6 in which the attachment member is adapted to pivotally support the retaining member to the fixed frame.
8. A locking mechanism according to any preceding claim in which the biassing means comprises a resilient member provided between the retaining member and the fixed frame.
9. A locking mechanism substantially as described herein with reference to and as illustrated in the accompanying drawings.
10. A window assembly comprising a movable frame which is adapted to move between an open and closed position relative to a fixed frame, the window assembly incorporating a lock assembly according to any one of claims 1 to 9.
11. A window assembly according to claim 10 of the top hung type, in which the movable frame is pivotally mounted at its top edge on the fixed frame and having a lower edge engaging a horizontal transom of the fixed frame, and in which the assembly space is secured to the upper face of the transom so that when the window is closed the lock assembly is wholly or partically accommodated within a gap defined between the lower edge of the movable frame and the upper face of the transom.
12. A window assembly substantially as described herein with reference to and as illustrated in the accompanying drawings.