GB2120312A

GB2120312A - Keep plates for locks

Info

Publication number: GB2120312A
Application number: GB08312484A
Authority: GB
Inventors: Laurence George Morgan
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-05-19
Filing date: 1983-05-06
Publication date: 1983-11-30
Also published as: ATE24571T1; DE3274891D1; EP0094461A1; GB8312484D0; EP0094461B1; GB2120312B

Abstract

An elongate leaf (22a) is connected to a first member, e.g. a door (4), along substantially the whole of one longitudinal edge portion (26), the other longitudinal edge portion (28) being pivotable through an acute angle between an unlocking position and a locking position in which the edge portion (28) is capable of engaging an elongate step (18). The leaf (22a) is preferably pivoted by a bolt (29) connected to it.

Description

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GB 2 120 312 A 1

SPECIFICATION

Improvements in or relating to locking devices

This invention relates to locking devices comprising a locking member and a keep plate, i.e.

5 a plate having an aperture or recess defining a step engageable by the locking member in the locking position.

No matter how secure a locking device is against picking or against forcing back or severing 10 of the locking member, this will be of little avail against attack with a sledgehammer so as to cause failure at the weakest point. One typical point of weakness is the keep plate.

The present invention is based on the idea of 15 dissipating impacts applied to a locking arrangement, by including elements of resiliently deformable material in the locking arrangement, particularly in conjunction with elongate metal plates.

20 In one aspect the invention provides an elongate metal plate for fixing to a surface of a member which requires strengthening, the plate having a longitudinal flange which is to be received in a slot in the member, at least one side 25 of the flange being in contact over the major part of its area with a resiliently deformable material. A plurality of such flanges and associated resiliently deformable material may be provided if desired.

The plate may be in the form of a plate, which 30 may be of any practical length and may have more than one aperture or recess for receiving corresponding locking members. A box or boxes could be provided on the rear side of the keep plate, to receive the locking member(s) projecting 35 through the aperture(s), in order to frustrate attempts to force the locking member(s) back with a jemmy.

The resiliently deformable material may be rubber, synthetic rubber, resiliently deformable 40 plastics material such as nylon, a visco-elastic material (e.g. a visco-elastic adhesive), or cork, for example.

In another aspect the invention provides a locking device comprising a locking member and a ; 45 keep plate as defined above. The preferred device , comprises an elongate hinge having a first leaf for ! fixing to a surface and a second leaf constituting the locking member, and means for pivoting the second leaf between an unlocking position in 50 which it is substantially parallel to the first leaf and a locking position in which it is at an acute angle to the first leaf, the keep plate defining a step engageable by the free edge portion of the second leaf in the locking position. The first leaf preferably 55 has a longitudinal flange which is to be received in a slot in the said surface, at least one side of the flange being in contact over the major part of its area with a resiliently deformable material.

The invention will be described further, by way 60 of example, with reference to the accompanying drawings, in which:

Figure 1 is a horizontal section through a door and a door-frame provided with a locking member and a keep plate, respectively;

Figure 2 is a fragmentary exploded perspective view of the locking member and associated parts;

Figure 3 is a view similar to Figure 1, in a second embodiment;

Figure 4 shows the keep plate of the second embodiment;

Figure 5 is a horizontal section through the keep plate; and

Figures 6 and 7 are similar views of alternative embodiments of the keep plate.

Referring first to Figures 1 and 2, the doorframe has a door-post 2 provided with a rebate. The door 4 closes against an optional rubber strip 7 fixed in the rebate. The rebate surface 3 facing the edge surface 5 of the door is provided with an elongate keep plate 16 which cooperates with a locking mechanism (described below) mounted on the door. The keep plate 16 is, for example, 60 cm in height and defines an elongate recess delimited by a sloping base 17 and a step 18. The base 17 slopes at an angle of less than 45° (in the illustrated embodiment about 25°) relative to the perpendicular to the door and is screwed to the door-post 2 at points spaced along its height. The inner edge of the plate 16 is formed with a flange 46 which extends into a slot in the rebate surface 3 and is covered on one side by a strip 47 of rubber or other resiliently deformable material, serving as a shock absorbing element, thus strengthening the door-post.

The locking mechanism mounted on the door 4 comprises a piano-type hinge 21 more or less equal in height to the keep plate 16. The hinge 21 has two leaves 22a, 226, one being narrower than the other. The narrower leaf 22b is screwed to the edge surface 5 of the door at points spaced along its height, and its free edge has a flange 23b which projects into a slot 25 and is covered on one side by a strip 24 of rubber or other resiliently deformable material serving as a shock absorbing element, thus strengthening the edge of the door. The inner longitudinal edge portion 26 of the leaf 22a is connected along the whole of its length to the leaf 22b by the hinge pin 27 and the leaf 27a is pivotable through about 25°, between an unlocking position (shown in broken line in Figure 1) in which it is substantially parallel with the leaf 22b and clear of the keep plate 16 and a locking position (full line) in which it is capable of engaging the step 18 to prevent the door from opening. The free edge portion 28 of the leaf 22a has a flange 23a which increases the friction between the leaf 22a and the step 18 and thus hinders escape of the leaf from the recess in the keep plate 16 if the door is attacked violently. The flange 23a is narrower than the step 18 so as not to facilitate the insertion of a jemmy between the leaf 22a and the keep plate 16.

It will be appreciated that the elongate keep plate 17 strengthens the rebate surface 3 where it receives the locking member constituted by the leaf 22a. Similarly the leaf 22b strengthens the edge surface 5 of the door in the region of the locking mechanism. The resiliently deformable strips 24 and 47 in conjunction with the flanges

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GB 2 120 312 A 2

236 and 46 projecting into the door and the doorpost, respectively, both serve to dissipate impacts inflicted upon the locking device during a violent attack. The sloping base 17 of the recess in the 5 keep plate 16 supports the leaf 22a against bending.

Movement of the leaf 22a is controlled by a bolt 29 extending from a conventional operating mechanism whose housing 32 is embedded in the 10 door. The bolt 2 9 is bifurcated and its upper and lower limbs 29a, 296 have aligned vertical holes 41a, 416 receiving a pin 42 which passes through a bracket 43 fixed to the leaf 22a, thereby connecting the bolt to the leaf.

15 In the locking device illustrated in Figure 3, the locking mechanism 51 is received in a mortice in a door 62 (or any other member which is to be locked) and a keep plate 63 is mounted flush with the surface of a rebate in the door-frame 64 (or 20 any other frame member to which the member 62 is to be locked) and preferably as close to the stop as possible. The plate 63 has an aperture 61 which receives the locking member or bolt 52 of the locking mechanism 51. One or more additional 25 apertures to receive additional bolts or latch bolts may be provided.

A flange 66 projects from the rear of the plate 63 into a recess in the door-frame and is in contact with a resiliently deformable element 67. 30 Figures 5 to 7 show various possible arrangements of the flange 66 and the element 67. Additional resiliently deformable elements can be provided as indicated in broken line in Figures 6 and 7. Furthermore a second flange with an 35 associated element can be provided at or near the opposite edge of the plate if desired. As shown in Figure 7, the rear side of the plate may have a box 65 into which the bolt 2 will project.

The plate is preferably of steel or brass, and 40 may be plastics-coated. The flanged section may be produced by casting or extrusion or by bending.

Claims

1. An elongate metal plate for fixing to a surface of a member which requires 45 strengthening, the plate having a longitudinal flange which is to be received in a slot in the member, at least one side of the flange being in contact over the major part of its area with a resiliently deformable material.

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2. A plate as claimed in claim 1, in the form of a keep plate.

3. A locking device comprising a locking member and a keep plate according to claim 2.

4. A locking device as claimed in claim 3,

55 comprising an elongate hinge having a first leaf for fixing to a surface and a second leaf constituting the locking member, and means for pivoting the second leaf between an unlocking position in which it is substantially parallel to the first leaf and 60 a locking position in which it is at an acute angle to the first leaf, the keep plate defining a step engageable by the free edge portion of the second leaf in the locking position.

5. A locking device as claimed in claim 4, in 65 which the first leaf has a longitudinal flange which is to be received in a slot in the said surface, at least one side of the flange being in contact over the major part of its area with a resiliently deformable material.

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6. A locking device as claimed in claim 4 or 5, in which the pivoting means comprises a bifurcated bolt connected to the second leaf by a bracket fixed to the leaf and a pin which extends between the two limbs of the bolt and through the 75 bracket.

7. A keep plate substantially as described with reference to, and as shown in. Figure 1, Figures 3 to 5, Figure 6, or Figure 7 of the accompanying drawings.

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8. A locking device substantially as described with reference to, and as shown in. Figures 1 and 2 or Figures 3 to 7 of the accompanying drawings.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1983. Published by the Patent Office 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.