GB2250772A - Locking mechanisms - Google Patents

Abstract

In a locking mechanism of the sort by which a door or window that swings open may be secured to the door or window frame a U-section (channel) profile (31) extending along the edge of one pan co-operates with an overlapping L-section profile (32) extending along the other to permit one-way relative swinging movement only, and a bar-like pressure strip (33) within and extending along the U-profile (31) can be moved into or out of movement-preventing contact with the L-profile edge surface (38). <IMAGE>

Description

Locking Mechanisms This invention relates to locking mechanisms, and concerns in particular a novel type of lock suitable for use with a door or window.

For the most part present-day "locks" by which a part, such as a door or window, that swings open relative to another part, such as the door or window frame, may be secured thereto consist of a pin member mounted flush with the edge of and generally in the plane of one of the parts (usually the swinging part) and movable so as to project laterally therefrom into a corresponding receptacle member mounted flush with the edge of the other of the parts (usually the stationary part). When the pin is retracted, flush with the edge, the swinging part can swing relative to the stationary part, but when it is extended, so as to project into the receptacle, this relative swinging movement is prevented. Lock mechanisms vary in simplicity from the ordinary bolt, through the conventional lever-operated deadlock, to the Yale-type pin-in-barrel devices.It is difficult, however, to make such mechanisms provide a really high degree of security against the simple application of brute force. Indeed, unless the relevant parts are made of extremely sturdy and relatively massive materials it is often surprisingly easy to "Jemmy", or otherwise force, the two apart.

Various attempts have been made to overcome this problem, including one in which the pin member was in effect a long strip extending the entire length of the relevant edge (and projecting into a receptacle similarly extending the length of the other part's edge), but none have been especially successful, or easy to make, install and use. The present invention proposes a quite radical solution, in which a U-section (channel) profile extending along the edge of one part co-operates with an overlapping L-section profile extending along the other to permit one-way relative swinging movement only, and a bar-like pressure strip within and extending along the U-profile can be moved into or out of movement-preventing contact with the L-profile edge surface.

In one aspect, therefore, the invention provides a locking mechanism for the fixed and moving parts of a door or window or the like, which mechanism comprises: a U-section profile mountable (U-section inner surface outwards) on and extending along the edge of one part; an L-section profile mountable (L-section inner surface outwards) on and extending along the mating edge of the other part so as in use to co-operate therewith in an overlap fashion permitting one-way relative swinging movement only; and a bar-like pressure strip mounted within the channel of the U-profile and extending therealong, and movable between an in-section retracted position and an out-of-section projecting position, which positions are in use respectively out of and in swinging-movementpreventing contact with the L-profile's outwardly facing edge surface.

The invention provides a locking mechanism for the fixed and moving parts of a door, window, or the like.

Most usually the mechanism will be for a door and its frame, or for a window and its frame, although it might be that the mechanism could be used with a double door or window (where the "fixed" part is in fact the other of a pair of movable parts!). Normally, it is more convenient to have the locking handle (see below) operating the pressure strip on the moving part, so that preferably the U-profile will be on the moving part (the door or window) while the L-profile is on the fixed part (the frame).

The mechanism includes a U-profile and an L-profile. These may be secured onto the "normal" surrounds/frames of the moving and fixed parts (door and door-frame, say), or and very preferably - they may actually constitute, or be a portion of, those parts (so that, for instance, the U-profile is the surround for the panels of a door, while the L-profile is the frame of the door, and is directly mounted into the wall, or whatever, in which the doorway is placed).

Both the U- and the L-profiles are "mountable" on their respective parts. They may be so mounted in any convenient way - using screws, nuts, glue, or what-haveyou - and this needs no further comment here.

The U-section profile, or channel member, is of any convenient depth, width and sectional shape, but is preferably a fairly shallow U of generally rectangular section (as shown in the accompanying Drawings discussed hereinafter). Similarly, the L-section profile, which "matches" the U-profile, may also be of any suitable dimensions or shape, but is preferably fairly shallow and of rectangular section (but see below). If the L is such that its base is mounted on, and forms the edge of, the part, while the upright projects outwardly therefrom (towards, and into co-operating, swinging-movementrestricting, contact with the U-profile-on xhe other part), then the L's upright is short, so it is a shallow L.

The U- and L-profiles extend along the opposed, mating edges of the two parts. While naturally the two will best extend to the same extent, and be positioned so as to correspond one with the other, they do not need to extend along the entire length of the parts, so long as they so extend along a sufficient length such that they provide adequate locking effect. Normally, however, they will extend all along the relevant edge that is, along that edge of the swinging part opposite its hinged edge (and along the corresponding edge of the fixed part) - and will do so in one uninterrupted run (rather than in two or more adjacent runs of a lesser length).

The two sections in use co-operate one with the other to permit one-way swinging movement only. As can easily be seen, with a U-profile facing and "overlapping", an L-profile, provided that both "upright" arms of the U are to the same side of the L's upright, then the L's upright will prevent the U-profile moving to and past the L but will permit the U-profile to move away from the L.

Mounted within, and extending along, the U-profile is a bar-like pressure strip. This pressure strip is so mounted within the U-profile - preferably in a hinged manner, from the "inner" surface of one or other of the U's upright arms - that it can be forced, along its entire length, from a "retracted" position, where it is (preferably) wholly within the U-profile, and is completely out of contact with the L-profile, to a "projecting" position, where it is in surface-to-surface area contact with the outer surface of the L's base.

This surface/surface area contact prevents relative swinging movement of the two parts - and while the mere frictional engagement of the pressure strip and the L-profile can achieve this it is very much preferred to modify the L-profile's base shape (and correspondingly to shape the pressure strip) to enhance this effect.

Specifically, it is highly advantageous slightly to step or to ramp the L's base towards the U-profile (the step or ramp increasing in height nearer the non-upright end of the base), and correspondingly to step or ramp the pressure strip. In this way, when the strip and L-profile are brought into contact, the two step or ramp surfaces fit together, and the steps or ramps themselves act completely to prevent any relative swinging movement. A ramp example of this embodiment is described hereinafter with reference to the accompanying Drawings.

The pressure strip may preferably be hingedly mounted on its U-profile wall by means of an elongate ball-and-socket joint - like a tongue-and-grooved board, but with a rounded tongue fitting pivotally into a rounded groove. An example of this, too, is shown in the accompanying Drawings.

The pressure strip is movable from a retracted to a projected position. There are many ways, and forms of mechanical actuation arrangement, by which this can be achieved. One simple, and presently preferred, arrangement involves a suitable number (depending upon the length of the strip) of toggle, or elbow-joint, bars, especially with an over-centre action. Such a bar, linking the strip to the base of the U-profile, has a short effective length when bent, but a longer length when straight. In its short, bent configuration it will therefore hold the strip in the retracted position, while in its longer, straight configuration it will push the strip out into the projected position (and where, if the parts are "closed", it will co-operate with, and be in swinging-movement-preventing engagement with, the L-profile on the other part).

There may be several such bars, disposed at suitable intervals along the length of the strip1 and each may have its own actuator (see below) or may be linked to the adjacent bars so that all may share a single actuator.

The toggle bars may have an actuator (or a number thereof) that pulls/pushes the bar between its short, bent, pressure-st rip-retracted position and its long, straight, pressure-strip-projected position. Such an actuator is conveniently a short push/pull rod fixed to the bar {preferably to the joint therein) and extending out laterally of the U-profile through an aperture therein, where it may be attached to an actuating lever (with a cam action, say). The principle of such a cammed-lever-driven rod-actuator is shown in the accompanying Drawings, discussed hereinafter.

The various parts of the mechanism of the invention - the L- and the U-profiles, the pressure strip, the toggle bar, and so on - may be made of any suitable materials, especially one that may be shaped by an extrusion process. Typically, then, they will be made of aluminium (or an alloy thereof) or a plastics substance like PVC.

An embodiment of the invention is now described, though by way of illustration only, with reference to the accompanying diagrammatic Drawings in which: Figure 1 shows a front view of a window in its frame; Figure 2A shows a part side elevation of a window/window frame combination using a locking mechanism according to the invent ion; Figure 2B shows a (part) sectional view of the combination of Figure 2A; and Figure 3 shows a detail of the locking mechanism used in the combination of Figures 2A/B, in the unlocked and locked state.

Figures 1 and 2A and 2B show a locking mechanism of the invention in use in a window/frame combination (the mechanism itself is best seen in Figure 3). The combination is a wall-mounted window with a pane of glass (11) in a surround (12) hingedly mounted (at 13) for swinging movement in a frame (14). The surround 12 has a handle (15) by which it can be locked to or unlocked from the frame 14 (by a camming action it operates a push/pull rod 21 - see Figure 2B - that actuates the toggle bar 35 - see Figure 3).

The window/frame combination of Figure 1 is shown (in part) in more detail in Figures 2A and B, and the locking mechanism is best explained with reference to Figure 3.

As can best be seen from Figure 3, the locking mechanism of the invention comprises an elongate shallow U-profile (31), an elongate shallow L-profile (32), and an elongate pressure strip (33) hingedly mounted via a tongue-and-groove joint (34) within the U-profile 31 and actuated by an elbow-joint over-centre toggle bar (35) mounted between ball-and-socket joints (41, 42) on the strip 33 and the U-profile's outer surface (36). The "free" end of the L-profile's base (37) is ramped Cat 38), and the strip 33 is correspondingly angled (39, 40).

Figure 3 shows the mechanism both in its unlocked state (with the strip 33 and toggle 35 in solid line) and in its locked state (with the two in dashed line).

It will be evident that when in the locked state, with the toggle bar 35 over centre, no amount of reasonable force will cause the two parts to move relatively (the U-profile 31 down, as shown, the L-section 32 up) one to the other because the co-operating ramp 38/pressure strip 33 prevents any such movement.

Claims (12)

1. A locking mechanism for the fixed and moving parts of a door or window or the like, which mechanism comprises: a U-section profile mountable (U-section inner surface outwards) on and extending along the edge of one part; an L-section profile mountable (L-section inner surface outwards) on and extending along the mating edge of the other part so as in use to co-operate with the U-section profile in an overlap fashion permitting oneway relative swinging movement only; and a bar-like pressure strip mounted within the channel of the U-profile and extending therealong, and movable between an in-section retracted position and an out-of-section projecting position, which positions are in use respectively out of and in swinging-movementpreventing contact with the L-profile's outwardly facing edge surface.

2. A locking mechanism as claimed in Claim 1, wherein the U-profile is on the moving part (the door or window) while the L-profile is on the fixed part (the frame).

3. A locking mechanism as claimed in either of the preceding Claims, wherein the U-profile and L-profile actually constitute, or are a portion of, the moving and fixed parts, and the U-profile is the surround for the moving part while the L-profile is the fixed frame in which that part moves.

4. A locking mechanism as claimed in any of the preceding Claims, wherein the U-section profile, or channel member, is a fairly shallow U of generally rectangular section, and the L-section profile, which "matches" the U-profile, is also fairly shallow and of rectangular section

5. A locking mechanism as claimed in any of the preceding Claims, wherein the U- and L-profiles extend along the entire length of the opposed, mating edges of the two parts.

6. A locking mechanism as claimed in any of the preceding Claims, wherein the bar-like pressure strip is mounted within the U-profile in a hinged manner, from the "inner" surface of one or other of the U's upright arms.

7. A locking mechanism as claimed in any of the preceding Claims, wherein the pressure strip is hingedly mounted on its U-profile wall by means of an elongate ball-and-socket joint.

8. A locking mechanism as claimed in any of the preceding Claims, wherein the bar-like pressure strip is so mounted that it can be forced, along its entire length, from a "retracted" position, where it is wholly within the U-profile, and is completely out of contact with the L-profile, to a "projecting" position, where it is in surface-to-surface area contact with the outer surface of the L's base.

9. A locking mechanism as claimed in any of the preceding Claims, wherein the L-profile's base shape is stepped or ramped towards the U-profile (the step or ramp increasing in height nearer the non-upright end of the base), and the pressure strip is correspondingly stepped or ramped, such that when the strip and L-profile are brought into contact, the two step or ramp surfaces fit together, and the steps or ramps themselves act completely to prevent any relative swinging movement.

10. A locking mechanism as claimed in any of the preceding Claims, wherein, to move the pressure strip from a retracted to a projected position, there is provided a suitable number of toggle, or elbow-joint, bars, with an over-centre action, each linking the strip to the base of the U-profile, and having a short effective length when bent, but a longer length when straight.

11. A locking mechanism as claimed in any of the preceding Claims, wherein each toggle bar is associated with an actuator that pulls/pushes the bar between its short, bent, pressure-strip-retracted position and its long, straight, pressure-strip-projected position, this actuator being a short push/pull rod fixed to the bar's joint and extending out laterally of the U-profile through an aperture therein, where it may be attached to an actuating lever.

12. A locking mechanism as claimed in any of the preceding Claims and substantially as described hereinbefore.