GB2206921A - Latches - Google Patents

Abstract

A latch, for a sliding sash window, comprising a static member 12 and a slider 13 which is held in a normally extended condition so that its head 30 slidably engaged a guide 15 of the window. The slider is retractable to disengage from the guide by displacing a manually operable part 38 downwards about a resilient hinge 33, connecting the part 38 to the head 30, to disengage a stop portion 39 from an abutment 22 on the static member. <IMAGE>

Description

LATCHES This invention concerns sliding sash windows, and latches and like retaining means for such windows, and for other closure members such as doors, windows and latches.

To facilitate cleansing of sliding sash windows, of a kind comprising a sash frame slidable in a outer frame, it is known to provide pivots at the bottom of the sash frame and latches at the top of the sash frame, which latches are releasable to allow the sash frame to be swung out of the plane of the sash frame about an axis passing through the pivots.

Such known latches are difficult to actuate, relatively complex, can be unreliable, and, if the widow is relatively wide, can give rise to difficulties and hazard. For example, one known latch comprises three plastics mouldings, a metal pressing and a helical coil spring; and to release the latch two of the mouldings require sequential manipulation, and one of these mouldings needs to be returned by hand upon reclosing of the window.

An object of the invention is to provide a simple to operate, reliable, safe and low cost latch for such windows.

According to the present invention there is provided a latch comprising a static member and a slider longitudinally slidable in or relative to the static member between an extended position, in which a head of the slider projects from the static member, and a retracted position in which the head is retracted towards or into the static member, the static member having an opening therein for a manually operable part of the slider; and characterised in that said manually operable part is mounted or formed on a flexibly resilient part of the slider so as to be displaceable,. against a restoring force provided at least partially by said resilient part, in a direction transverse to the longitudinal direction to disengage a stop portion of the slider from an abutment provided on or by the static member.

The manually operable part preferably includes a knob which projects through said opening.

The slider may be biased by a spring towards said extended position, and the stop portion may be engageable with a further abutment to retain the slider in the retracted position against the thrust of said spring.

The slider is a single moulding of a plastics material, and the static member is preferably also a single plastics moulding.

The invention includes a sliding sash widow provided with latches of the invention.

The head may be shaped to slidably cooperate with a guide of the sash frame in normal sliding operation of the sash window.

The invention will be described further, by way of example, with reference to the accompanying diagrammatic drawings, wherein; FIGURE 1 shows a vertical longitudinal cross section through a latch of the invention; FIGURE 2 is a plan view of the latch; and FIGURE 3 is a view, similar to FIGURE 1, showing a second embodiment of the invention.

In both embodiments, the latch 11 comprises a static member 12 and a slider 13, each being a single moulding of a plastics material e.g. acetal plastics for the slider. The latch 11 is of a form suitable for use with a sliding sash window having a sash frame, including an upper extrusion 14 of aluminium or plastics material, and a outer frame provided with a cylindrical guide 15 (which may house a spring to compensate for the weight of the window in known manner) in an upright guide extrusion 16 of the outer frame.

In the first embodiment, the static member 12 comprises an elongate body 20 having an elongate aperture 21 therein and an abutment 22 provided by a surface of the body at one end of the aperture 21. The body 20 is thickened around the aperture to provide a downwardly directed thickening 23, and said thickening may be extended, adjacent said one end, to provide a further, but oppositely directed, abutment 24, indicated in broken lines in FIGURES 1. The body also provides, adjacent its ends, two hollow downwardly extending spigots 25 with chamfered openings 26 in the upper surface 27 of the body.

The slider 13 comprises a head 30 shaped to engage the guide 15; a body 31 providing elongate slots 32 through which the spigots 25 extend; a flexible resilient part 33; and a manually operable part 36. The head may be cut back, e.g. as indicated in broken lines at 34, to provide a "slam" closing ramp. The resilient part 33 provides a flexible cantilever connection between the part 36 and the head 30 or body 31, and both said parts 33 and 36 extend away from the head in a further slot 37 in the body 31. The part 36 has an upwardly projecting knob 38, which extends through the aperture 21; and a stop portion 39 having a rear face 35 which, in the extended condition of the slider 13, engages or confronts the abutment 22 to prevent or hinder the slider being retracted, i.e. moved to the right of its extended position in which it is shown in FIGURE 1.However, the rear face 35 of the stop portion may be rounded or inclined to provide a ramp which permits the slider to be driven back to permit slam closing of the window; whereas in the embodiment shown in FIGURE 1 said rear face 35 and the abutment are perpendicular to the slider to provide a positive stop requiring disengagement before retraction is possible. The knob 38 is exposed so that pressure can be applied manually a) to depress the part 36 relative to the body 31, against a restoring force provided by the resilient part 33, until the portion 39 is moved downwards from the abutment 22, and b) to move the slider to the right from the extended condition to a retracted condition in which the knob abuts or is proximal to the abutment 22, to retract the head towards the static member 12 for disengaging the head 30 from the sash frame guide 15 and extrusion 16.

This form of the latch 10 is let partially into the upper extrusion of the sash frame so that the body 31 extends within the extrusion 14, and the body 20 conceals and overlies an opening cut into the extrusion 14. The body 20 is secured to a support 40, provided in or by the extrusion 14, by fasteners.

In use, the slider 13 is restrained against horizontal movement, other than in the longitudinal direction, engagement of the body 30 with the peripheral surfaces of the spigots; is restrained against upwards movement by engagement with an under-surface of 42 of the extrusion 14; and is restrained against downwards movement by engagement with the support 40.

The invention is not confined to details of the foregoing example, and many variations and modifications are possible within the scope of the invention, which scope includes any novel part or feature, and any novel combination thereof, which is or are disclosed herein.

For example, the latch may be simplified, especially for use as a window latch and especially constructed to permit slam closing or locking whilst retaining sufficient blocking of or resistance to retraction of the slider to hinder or prevent inadvertent operation or operation of the latch by a small child. Such a modified embodiment is shown in FIGURE 3 from which it can be seen that the modifications are such that the flexible resilient part 33A is extended to underlie the aperture 21, carries both the knob 38 and the stop portion 39, is upwardly bowed and serves as an integral part of the body to provide a resilient bridging connection between the head 30 and the rear end portion of the body. In effect the manually operable part is now an integral but slightly flexible mid-portion of the body. The stop portion 39 has the ramped rear face 35, and a similarly ramped front face to permit return of the slider by the spring 47.

The degree of resistance to retraction of the slider in either embodiment can be varied by varying the height and/or inclination or curvature of said rear face, and/or the slope of any rounding chamfer or inclination of the abutment 22 as well as by varying the thrust of the spring and the stiffness of the resilient part. The static member 12A is simpler and shallower than the member 12.

For further example, the latch may be formed to incorporate the support into, or to secure the support onto, the static member, so as, for instance, to suit other forms of sliding sash windows, e.g. windows having timber frames; and the spigots 25 may be omitted in forms in which the static member or support are arranged to confine the body of the slider to longitudinal movement.

The static member may have formations projecting laterally of or in the sides of its body, to permit the latch to be secured to a window.

The flexible part may be of any suitable form and disposed at either end of the manually displaceable part.

The latter may be modified to omit the knob.

The thickening may be extended as indicated in broken lines in FIGURE 1 to provide the further abutment 24 for engagement by a face 46 of the stop portion 39 to retain the slider in the retracted position automatically when the knob is released after retraction, especially if an, optional, bias spring 46 is provided to urge the slider to the extended position. The bias spring is necessary for embodiments adapted to permit slam closing.

The head may be of any suitable form, and may have the same, or even smaller, cross sectional area as or than the adjacent part of the body of the slider.

It will be readily appreciated that the static member may be integrally or substantially integrally provided by the sash frame extrusion or extrusions with modification to provide the elongate aperture 21 directly in the extrusion.

It will be further appreciated that the invention is applicable to shoot-bolts, e.g. for gates, doors and latches as well as windows, especially for situations where weight , corrosion resistance and visual appearance are important, by utilising the slider or a suitably modified form thereof as the shoot; and utilising a modified static member, which preferably includes support, as a shoot housing.

Claims (16)

1. A latch comprising a static member and a slider longitudinally slidable in or relative to the static member between an extended position, in which a head of the slider projects from the static member and a retracted position in which the head is retracted towards or into the static member, the static member having an opening therein for a manually operable part of the slider; and characterised in that said manually operable part is mounted or formed on a flexibly resilient part of the slider so as to be displaceable, against a restoring force at least partially provided by said resilient part, in a direction transverse to the longitudinal direction to disengage a stop portion of the slider from an abutment provided by the static member.

2. A latch as claimed in Claim 1 wherein the slider is biased by a spring towards said extended position.

3. A latch as claimed in Claim 2 wherein the stop portion is engageable with a further abutment to retain the slider in the retracted position against the thrust of said spring.

4. A latch as claimed in Claim 1, 2 or 3 wherein the manually operable part includes a knob which projects through said opening.

5. A latch as claimed in Claim 1, 2, 3 or 4 wherein the slider is a single moulding of a plastics material.

6. A latch as claimed in Claim 5 wherein the static member is also a single plastics moulding.

7. A latch as claimed in any preceding claim wherein the abutment is provided by a surface defining one end of the opening.

8. A latch as claimed in any preceding claim wherein the resilient part is disposed between and connects the manually operable part to the head.

9. A latch as claimed in any preceding claim wherein the engagement between the stop portion and the abutment provides a positive stop to prevent retraction of the slider prior to disengagement.

10. A latch as claimed in any one of Claims 2 to 7 wherein the engagement between the stop portion and abutment is made at or through at least one surface thereof which is inclined to the direction of retraction or is curved or chamfered to permit the slider to be driven longitudinally to overcome the resistance provided by said engagement.

11. A latch as claimed in Claim 10 wherein said resilient part forms an integral bridge between the head and a rear end part of the slider, and wherein the spring acts on said rear end part.

12. A latch substantially as hereinbefore described with reference to FIGURE 1 and 2 or FIGURE 3 of the accompanying drawing.

13. A sliding sash window provided with latches as claimed in any preceding claim so that the heads are extendable to engage in an outer frame of the window.

14. A window as claimed in Claim 13 wherein the heads are shaped to slidably cooperate with sash guides of the outer frame in normal sliding operation of the sash window.

15. A window as claimed in Claim 13 or 14 wherein the heads are shaped to permit slam closing of the window.

16. A window substantially as hereinbefore described with reference to the FIGURES 1 and 2 or FIGURE 3 of the accompanying drawings.