GB1570307A - Lock - Google Patents

Description

(54) LOCK (54) LOCK (71) I, GEORGE HATCH, a British Subject, of 23 Grimshaw Avenue, Failsworth, in the County of Greater Manchester, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention concerns a lock of the kind (hereinafter referred to as "of the kind described") which is suitable for use on e.g. a door and which includes a bolt axially slidable between an operative position wherein it projects into a socket or keeper in or on a fixed structure to which the door is connected, thereby to lock the door, and an inoperative position withdrawn from the socket and permitting the door to be opened.

An object of the invention is to provide a novel construction of lock, of the kind described, which is particularly easy to operate, so that it can readily be locked and/or released manually by persons, such as invalids or the infirm, who have only very little manual strength, and yet can readily be constructed so as to be a so-called "deadlock" in which the bolt, when properly in its operative position, cannot be shifted, by external force, towards the inoperative position.

With this object in view, the present invention provides a lock of the kind described wherein one end of the bolt is pivotally connected to a cam disposed for pivotal and translational movements between a pair of guide surfaces extending transversely of the direction of movement of the bolt and a handle fixed to the cam to enable it to be pivoted and translated and by engagement with the guide surfaces to move the bolt between its two positions.

The guide surfaces may be provided by opposed parallel sidewalls of a guide slot in a body of the lock, a cover plate being secured to the body so as to mask the guide slot and ensure that the boss is retained therein.

The handle may project out of the body through a slot.

The boss may comprise simply a single circular disc to which the bolt is pivotally connected. Preferably it comprises a pair of discs connected together by a pivot pin by which the bolt is connected thereto.

The invention will be described further, by way of example, with reference to the accompanying drawings, which illustrate a preferred embodiment thereof, it being understood that the following description is illustrative, and not restrictive of the scope of the invention. In the drawings: Fig. 1 is a side elevation, partly cut away, showing a preferred embodiment of lock of the invention in a locking condition thereof; Fig. 2 is a similar view but showing the bolt in a condition intermediate the positions of Figs. 1 and 3; and Fig. 3 is a similar view but showing the lock in its open condition.

The said preferred embodiment of lock 10 of the invention comprises a cast metal main body 11 through which are fixing holes 21 by use of which the entire lock 10 can be secured into position, e.g. to a house or barn door, ready for use. The body 11 accommodates an axially slidable bolt 12 whose inner end 13 is pivotally connected by a pivot pin 14 to a cam 15 at an eccentric position. The cam 15, which comprises a pair of discs connected together by the pivot pin 14 is accommodated between guide surfaces provided by opposed parallel side walls 16, 17 of a guide slot 18 in the main body 11 and extending transversely to the direction of movement of the bolt 12.The diameter of the discs is substantially equal to the spacing between the side walls 16, 17 of the guide slot 18, so that the cam 15 is prevented from any substantial lateral movement within the guide slot 18, i.e. in the direction of movement of the bolt 12. However, the cam 15 can be manually rotated within the guide slot 18 by means of a radially-projecting handle (not shown) connected to the cam 15 and which projects through a slot (also not shown) in a cover plate 19 screwed to the main body 11 so as to mask the guide slot 18 and ensure that the cam 15 is retained therein.

Upon manual swinging of the handle, the cam 15 is pivoted correspondingly. Pivoting of the cam 15 produces a cam action between the peripheral edge of the cam 15 and the side walls 16, 17 of the guide slot 18 so that the bolt 12 is moved axially between its operative and inoperative positions (Figs. 1 and 3 respectively). As this occurs, the cam 15 makes a reciprocal movement along the guide slot 18 to allow for a straight-line movement along the guide slot 18 to allow for a straight-line movement of the pivot pin 14 across the guide slot 18 under constraint of the axial movement of the bolt 12.

When the bolt 12 is properly in its operative position (Fig. 1) wherein it projects into a socket, keeper or the like (not shown) in or on a fixed structure, the centre ofthe cam 15 is directly aligned with the pivot pin 14 and the bolt axis. In this position the bolt 12 acts as a "deadlock" since it cannot be moved by external force towards its inoperative position. This is because force on the bolt 12 does not have a turning effect on the cam 15 which thus remains in a position directly obstructing movement of the bolt 12 towards its inoperative position.

It will be appreciated that detail modifications may be made without departing from the scope of the invention, for example the cam 15 may comprise simply a single disc to which the bolt 12 is pivotally connected. Key locking means also may be provided to prevent unauthorised opening of the lock 10 or, alternatively, the operating handle may be removable from the lock 10 for the same purpose.

WHAT WE CLAIM IS:- 1. A lock of the kind described wherein one end of the bolt is pivotally connected to a cam disposed for pivotal and translational movements between a pair of guide surfaces extending transversely of the direction of movement of the bolt and a handle fixed to the cam to enable it to be pivoted and translated and by engagement with the guide surfaces to move the bolt between its two positions.

2. A lock as claimed in claim 1, wherein the guide surfaces provided by opposed parallel sidewalls of a guide slot in a body of the lock, a cover plate being secured to the body so as to mask the guide slot and ensure that the boss is retained therein.

3. A lock as claimed in claim 1 or 2, wherein the cam has a handle secured thereto and projecting out of the body through a slot.

4. A lock as claimed in any of claims 1, 2 and 3, wherein the cam comprises a single disc.

5. A lock as claimed in any of claims 1, 2 or 3 wherein the boss comprises a pair of discs connected together by a pivot pin by which the bolt is connected thereto.

6. A lock substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. bolt 12 is moved axially between its operative and inoperative positions (Figs. 1 and 3 respectively). As this occurs, the cam 15 makes a reciprocal movement along the guide slot 18 to allow for a straight-line movement along the guide slot 18 to allow for a straight-line movement of the pivot pin 14 across the guide slot 18 under constraint of the axial movement of the bolt 12. When the bolt 12 is properly in its operative position (Fig. 1) wherein it projects into a socket, keeper or the like (not shown) in or on a fixed structure, the centre ofthe cam 15 is directly aligned with the pivot pin 14 and the bolt axis. In this position the bolt 12 acts as a "deadlock" since it cannot be moved by external force towards its inoperative position. This is because force on the bolt 12 does not have a turning effect on the cam 15 which thus remains in a position directly obstructing movement of the bolt 12 towards its inoperative position. It will be appreciated that detail modifications may be made without departing from the scope of the invention, for example the cam 15 may comprise simply a single disc to which the bolt 12 is pivotally connected. Key locking means also may be provided to prevent unauthorised opening of the lock 10 or, alternatively, the operating handle may be removable from the lock 10 for the same purpose. WHAT WE CLAIM IS:-

1. A lock of the kind described wherein one end of the bolt is pivotally connected to a cam disposed for pivotal and translational movements between a pair of guide surfaces extending transversely of the direction of movement of the bolt and a handle fixed to the cam to enable it to be pivoted and translated and by engagement with the guide surfaces to move the bolt between its two positions.

2. A lock as claimed in claim 1, wherein the guide surfaces provided by opposed parallel sidewalls of a guide slot in a body of the lock, a cover plate being secured to the body so as to mask the guide slot and ensure that the boss is retained therein.

3. A lock as claimed in claim 1 or 2, wherein the cam has a handle secured thereto and projecting out of the body through a slot.

4. A lock as claimed in any of claims 1, 2 and 3, wherein the cam comprises a single disc.

5. A lock as claimed in any of claims 1, 2 or 3 wherein the boss comprises a pair of discs connected together by a pivot pin by which the bolt is connected thereto.

6. A lock substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.