GB2276190A

GB2276190A - Lock assembly

Info

Publication number: GB2276190A
Application number: GB9404816A
Authority: GB
Inventors: Izak Johannes Pretorius
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-11
Filing date: 1994-03-11
Publication date: 1994-09-21
Also published as: ZA941659B; GB9404816D0

Abstract

A lock assembly is provided for locking a movable stile (6, 7) associated with a closure of an accessway to another stile (7, 6) such as a relatively fixed stile. One stile (6), conveniently the fixed stile, has one or more projections (8a, 8b, 8c), preferably headed projections, extending therefrom towards the other stile and the latter has a locking member (17) for the projections, to lock the two stiles together in an operative locked position. The locking member is biased to the operative position, conveniently by gravity, and is automatically moved against the bias by the projection on closure of the closure to become automatically operative. The lock assembly is particularly well suited to use in conjunction with laterally expanding security grilles. <IMAGE>

Description

LOCK ASSEMBLY This invention relates to a lock assembly for closures having laterally movable stiles and, for example, may have application in security grille closures comprising a laterally expandable and collapsible security grille.

A grille is usually fixed at one vertical edge relative to a fixed frame member and has a laterally movable stile or frame member (hereinafter referred to as the movable stile), movable relative to a stationery stile or frame member (hereinafter referred to as the fixed stile). The latter is fixed relative to one side of an accessway which is to be protected by the grille.

In known laterally movable or slidable closures, the movable stile is releasably locked to the fixed stile by means of key operated locks in order to render the closure functional. One disadvantage of this arrangement is that, in an emergency situation, it may be extremely difficult to effect the locking of the movable stile to the fixed stile by operating a key. This is particularly so if an intruder or attacker is in the immediate vicinity, or hard on the heels of a person wishing to render the closure effective in an extremely rapid manner. Also, it may be that the key is not immediately available or is difficult to insert into the keyhole under emergency conditions.

It is an object of the present invention to alleviate the problems of the prior art. It is also an object of this invention to provide an improved lock assembly for a closure having a laterally movable stile, and closures embodying such lock assembly, wherein the aforementioned disadvantages are alleviated.

It is to be noted that in this specification the term "movable stile" and "fixed stile" will be used for the purposes of clarity of description. However, the fixed stile may also be movable in cases where two movable closures meet at a central position.

According to a first aspect of this invention, there is provided a lock assembly for a closure having a laterally movable stile co-operable with a fixed stile, the lock assembly comprising at least one locking projection or formation projecting from either the movable or the fixed stile of a closure assembly, and a co-operant locking member on the other of the movable and fixed stiles for co-operation with the projection to lock it relative to the latter stile and thereby lock the two stiles together, one of the locking member and projection being biased towards an operative co-operant locked position relative to the other of the projection and locking member, said one of the projection and locking member being shaped to move the other one of the projection and locking member against its bias during movement of the said one of the projection and locking member towards the locked position following which the said one of the projection and locking member is moved by its bias into the operative locked position relative to the other one of the projection and locking member.

In a preferred embodiment, there are two, three or more spaced projections on the relevant stile, each of which has a co-operant locking member associated with the other stile. A said projection may be a headed projection wherein the head communicates with a neck portion through a shoulder. In this case, the locking member may be adapted to engage behind the shoulder in the operative position. The locking member may assume the form of a plate or bar slidable in its own plane and having one or more formations for engaging behind the shoulder of one or more said projections. Preferably, the locking member includes a formation for engaging a said projection, the formation comprising a zone of a plate or bar adjacent a slot. The slot may be located intermediate the ends of a locking plate and/or may communicate with a larger hole to provide a keyhole shaped aperture in a locking plate.

Preferably, key operated locking means are provided for releasing the locking member against the bias thereof.

Conveniently, biasing of the locking member may be achieved simply using gravity. It is preferred that, where a plurality of projections are present, locking members for co-operation therewith are integral with each other to provide a single movable part. It is also preferred, where a plurity of projections are used, and a single member imparts movement to all the locking members, that the single member be arranged for engagement at different stages of movement of the two stiles together by the different projections so that, in effect, each projection moves the member by a portion of its total movement.

The locking member may, if required, be remotely activated for movement against its bias. In such a case, an electric solenoid may be used and the solenoid could be activated by a remote push button switch, an infra red or radio operated remote control arrangement, at even a mechanical connection such as a Bowden cable. Also, a Bowden cable could be used directly (ie. without a solenoid).

The movement of the movable stile may be substantially parallel to the plane of an aperture in which the closure is mounted. Alternatively, the closure may be hinged about one side of the aperture so that the movable stile describes an arc as it is moved into engagement with the fixed stile. The laterally movable stile is preferably movable in a substantially horizontal sliding movement in the installed closure, but may be movable in other directions such as in a substantially vertical direction.

According to a further aspect of the invention, there is provided a security grille including a lock assembly according to the first aspect of the invention. The security grille itself may comprise pivotally linked, diagonally extending grille members, or may comprise a series of roughly parallel upwardly extending members interlinked by transversely extending lattice or link members.

The present invention may be carried out in various ways and a preferred embodiment of a lock assembly in accordance with the invention and its application to a security grille will now be described by way of example with reference to the accompanying drawings, in which FIG. 1 is an elevation of a preferred embodiment of an expandable security grille closure incorporating a preferred lock assembly, in accordance with the invention, in a closed position; FIG. 2 is an elevation corresponding to Figure 1 but showing an open position; and FIG 3. is a detailed, partly broken away isometric view of the portion of the length of the movable and fixed stiles indicated by bracket "A" in Figures 1 and 2 and containing the locking assembly.

Referring to the drawings, a security grille 1 includes a surrounding frame 2 and a series of vertical security bars 3 interlinked at an upper, a central and a lower region 4 by transverse link or lattice members in a conventional way to form an expandable grille.

One edge of the grille is permanently associated with a fixed vertical frame member 5, whilst the other is associated with a movable stile 6, movable towards and away from a fixed stile 7 which is, in fact, the opposite frame member of a peripheral frame.

The movable stile 6 and fixed stile 7 are releasably lockable together in order to lock the security grille in a closed condition and the locking assembly is as shown in more detail in Fig. 3.

The movable stile 6 is provided with three spaced projections 8a, b and c extending from the centre thereof, each of the projections having a neck 9 and enlarged head 10 defining between them a shoulder 11.

Each of the heads terminates in a substantially conical formation 12. Finally, regarding the projections 8a, 8b and 8c, it is to be noted that the axial distance from the shoulder 10 to the base of the conical formation 12 is different in the case of all three projections and the purpose of this will be described more fully below. It must also be noted that the distance from the face 13 of the movable stile from which the projections project to the shoulder 11 is the same in all three cases.

The fixed stile 7 has three holes 14 therein through which the projections can pass when the security grille is in the fully closed position. The fixed stile is in the form of an aluminium extrusion and has two locating flanges 15 spaced from the inner surface of the front 16 of the fixed stile so that a movable elongate locking plate is confined to longitudinal movement relative to the fixed stile and in its own plane. The locking plate has three keyhole shaped apertures therethrough, each keyhole shaped aperture consisting of a circular hole 18 of substantially the same diameter as the holes 14 through the front face 16 of the stile, and a communicating slot portion 19 above the hole 18.

The arrangement is such that with three projections fully inserted into the holes 14 in the fixed stile, the locking plate 17 will be gravitationally biased downwardly to a position in which the zone adjacent the three slots 19 engage behind the shoulders 11 of the projections so that the two stiles are firmly locked together.

A key operated lock 20, mounted in the movable stile, has an operating lever 21 extending through a slot 22 in the front face 13 of the movable stile and opposite an access slot (not shown) in the fixed stile and a slot 23 in the locking plate 17. The arrangement is such that the key operated lock can be operated to raise the locking plate by engagement of the operating lever 21 with an end, the upper end in this case, of the slot 23 in the locking plate to lift it against the action of gravity. This lifting action causes the three holes 18 of the keyhole shaped formations to align with the holes 14 in the front face of the fixed stile. The projections can then be withdrawn and the security barrier opened.

In this embodiment of the invention it is to be noted that the end of the operating lever in the locked position acts as a stop to prevent upward movement of the locking plate, and therefore unauthorised tampering with the lock.

This is an important security feature as criminals cannot drill a hole in the stile and move the locking plate up to open the closure.

The arrangement of the three conical shaped formations 12 at the ends of the projections is such that, as the movable stile is moved towards the fixed stile, the conical formations enter the holes 14 and communication zone between the holes 18 and associated slots 19 of the keyhole shaped formations. Because of the different distances from the shoulders 11 to the conical formations 12, the conical formation 12 of the longest and lowermost projection 8c will firstly engage the locking plate to start lifting it. Once it has lifted it by a certain amount, the conical formation 12 of the middle projection 8b will engage the locking plate to lift it further and subsequently the shortest and uppermost projection 8a will have its conical formation 12 engage the associated keyhole formation of the locking plate.

Further movement of the movable stile towards the fixed stile will result in the projections passing fully into the holes 14 and 18 such that the locking plate will drop down behind the shoulders 11 of the projections with the neck portions 9 in the slots 19. The movable and fixed stiles are then once again locked together.

It will be understood that the locking assembly described above will be extremely secure and will automatically come into operation when the security grille is closed.

The disadvantages associated with existing arrangements are thereby avoided.

Numerous variations may be made to the embodiment of the invention described above without departing from the scope hereof. In particular the projections could assume any form and could, in fact, assume the form of tongues having transverse apertures therethrough for receiving locking formations. The locking plate could be replaced by any other suitable member and, the locking formations themselves need not be integral with the operating member. If required, the locking members could be resiliently biased, such as by a spring, towards their operative positions rather than being gravitationally biased. More than or less than three projections, holes and apertures could be employed.

In the case of a double sliding door arrangement where two slidable closures are movable towards and away from each other, the so termed fixed stile actually forms the stile at one end of the one door whilst the other door incorporate what is termed the movable stile.

The preferred construction described therefore provides a simple, yet highly effective, locking assembly for expandable security grille closures as well as security grille closures embodying same. Embodiments of lock assemblies incorporated in sliding doors, gates and other sliding closures, such as laterally sliding closures, in accordance with the invention, are also envisaged.

Claims

1. A lock assembly for a closure having a laterally movable stile co-operable with a fixed stile, the lock assembly comprising at least one locking projection projecting from one of the movable and the fixed stile of a closure assembly, and a co operant locking member on the other of the movable and fixed stiles for co-operation with the projection to lock it relative to the other stile and thereby lock the two stiles together, the locking member being biased towards its operative co-operant locked position relative to the projection, the projection being shaped to move the locking member against its bias during movement of the projection towards the locked position following which the locking member is moved by its bias into the operative locked position relative to the projection.

2. A lock assembly as claimed in claim 1 including two, three, or more projections on the associated stile, the projections being spaced apart thereon, and a co-operant locking member associated with the other stile for each projection.

3. A lock assembly as claimed in claim 2 in which the locking members for each projection are interconnected so as to operate in unison.

4. A lock assembly as claimed in claim 2 or claim 3 in which the locking members are integral with each other.

5. A lock assembly as claimed in any one of claims 1 to 4 in which the or each projection includes a head communicating with a neck portion by way of a shoulder, and the lock member is adapted to engage behind the shoulder in the operative locked position.

6. A lock assembly as claimed in claim 5 in which the locking member comprises a plate or bar slidable in its own plane and includes a formation for engaging behind the shoulder of a corresponding projection.

7. A lock assembly as claimed in claim 6 in which the formation of the locking member comprises a zone of the plate or bar adjacent a slot.

8. A lock assembly as claimed in claim 7 in which the slot is located intermediate the ends of the plate or bar and the slot communicates with a larger hole to provide a keyhole shaped aperture in the plate, the hole being dimensioned to allow a head of a co operant projection to pass therethrough.

9. A lock assembly as claimed in any one of the preceding claims which includes key-operated locking means for selectively releasing the locking member against the bias thereof.

10. A lock assembly as claimed in any one of the preceding claims in which the locking member is biased to its locked condition by gravity.

11. A lock assembly substantially as described herein with reference to the accompanying drawings.

12. A security grille including a lock assembly as claimed in any one of the preceding claims.

13. A security grille substantially as described herein with reference to the accompanying drawings.