GB2134589A - Locking bolts - Google Patents

Abstract

This invention relates to a lock having a housing in which is formed a pair of parallel bores. In one of said bores 11 is mounted a slidable bolt 12 which is movable between an operative locked position (shown) in which one of its ends projects from the housing and an inoperative retracted position, resilient means 19 being provided for moving said bolt from its operative position to its inoperative position. In the other bore 13 of the housing is mounted key operable means 14 which is connected to a bolt retaining member 21 and the latter is urged by further resilient means towards the position shown in which it engages and holds the bolt in its operative locked position. The bolt retaining member 21 is movable out of engagement with the bolt 12 by operation of said key operable means 14 against the force exerted by said further resilient means. <IMAGE>

Description

SPECIFICATION Lock This invention relates to a lock which is especially (but not exclusively) intended for use in securing in their closed positions pivoted windows, sliding windows and siiding doors of various kinds, the object of the invention being to provide such a lock in an improved form.

In accordance with the invention there is provided a lock which comprises a housing in a bore of which is mounted a slidable bolt which is movable relative to the housing between an operative locked position in which one of its ends projects from one side of said housing and an inoperative position in which said one end does not project or only projects by a small extent from said one side of the housing, said bolt being movable by resilient means from its operative position to its inoperative position when released from the operative position, there being also provided key-operable means which is mounted in a further bore in the housing which is parallel to said bore in which the bolt is mounted, the keyoperable means being connected to a bolt retaining member which is urged by further resilient means to engage and hold said bolt in its operative locked position and which is movable by operation of said key-operable means against the force exerted by said further resilient means to a position in which said first-mentioned resilient means will move the bolt to its inoperative position.

The aforesaid housing may be located within a separately formed casing and secured therein in any convenient manner but preferably the housing is formed as a die-casting (or in any other convenient manner) which is initially open on each of two opposite sides, said open sides being subsequently closed respectively by a pair of apertured plates which are secured to the housing after assembly of the various components has been completed.

The invention will now be more particularly described with reference to the accompanying drawings wherein Figure 1 is a view from one side of one example of a lock constructed in accordance with the invention, Figure 2 is a sectional view taken on the line A-A of Figure 1, Figure 3 is a view of the lock from the side thereof opposite to the side seen in Figure 1, but with adjacent closure plate removed, and Figure 4 is a side view of the housing, before assembly of the bolt, key-operable means, closure plates, bolt retaining member and resilient means, as seen in the same direction as is used for Figure 1.

Referring now to the drawings the example of a lock shown therein is provided with a housing 10 which is conveniently formed as a metallic diecasting. The housing is open on each of two opposite sides and is integrally formed internally with partitions which provide a bore 11 for receiving a bolt 1 2 and another bore 1 3 which is generally parallel to said bore 11 and which serves to receive key-operable means 14. The housing is also formed with two transverse bores 1 5 and 1 6 into which in use screws can be inserted for the purpose of fixing the lock to a window, or a door or the like.

The aforesaid bolt 1 2 is slidably mounted in said bore 11 so as to be movable relative to the housing 10 between an operative locked position (as shown in Figure 2) in which one end 17 of the bolt projects from one side of the housing as shown in Figure 2 to an inoperative or withdrawn position in which said end 1 7 of the bolt does not project from said side of the housing or only projects therefrom to a very small degree. The opposite end of the bolt is formed with a knurled head indicated by reference numeral 18 which projects from the opposite side of said housing 10 as seen in Figure 2.There is also provided resilient means in the form of a coil spring 19 which is located between a shoulder formed at one end of the bore 11 and a circlip 20 which is retained within a groove formed in the exterior of the stem of the bolt 12, said coil spring acting to urge the bolt 12 away from the operative locked position seen in Figure 2 to its inoperative position in which the projecting end 1 7 is withdrawn and the knurled head 1 8 of the bolt projects from the adjacent side of the housing to a greater extent than is seen in Figure 2.

Associated with said key-operable means 14 is a bolt retaining member 21 which is pivotally mounted in the housing 10 and which is engaged by a projecting eccentrically disposed lug 22 of said key-operable means 14 whereby rotation of said means by turning the key 23 will have the effect of slightly turning the member 21 against a rotational force acting on it and provided by further resilient means in the form of a torsional spring 23a.At its end remote from said torsional spring 23a the bolt retaining member 21 is formed with a recess having an edge 24 of somewhat reduced thickness which is adapted to enter into a further groove 25 formed in the bolt 1 2. The action of the torsion spring 23a is to press the bolt retaining member 21 into engagement with the bolt 12 so that if the knurled head 18 of said bolt 1 2 is pushed inwardly from its inoperative position against the force exerted by the coil spring 1 9 said edge 24 of the bolt retaining member will drop into the groove 25 when the latter is aligned with said member 21. The spring 23a then holds the member 21 to maintain the bolt in its operative locked position as seen in Figure 2. In this position the key 23 can be withdrawn.When it is required to unlock the bolt the key 23 is used to turn the key-operable means 14 in order to withdraw said edge 24 of the bolt retaining member 21 from the bolt groove 25 so as to permit the coil spring 19, acting on the circlip 20, to withdraw the bolt and move it to its inoperative position. After unlocking of the bolt has been effected the key 23 can again be removed and relocking can be achieved simply by pushing in the bolt 12 until engagement again occurs between the edge 24 of the member 21 and the groove 25 of the bolt 12.

The aforementioned open sides of the housing 10 are closed on completion of assembly of the lock by means of the two closure plates 26 and 27. The plate 26 is formed with two apertures and the bolt 1 2 extends through one of such apertures whereas the end of the key-operable means 1 4 having the key slot 28a (see Figure 1) is accessible through the other aperture. The plate 27 has one aperture through which the end 1 7 of the bolt projects. The housing 10 is formed on each side with a shallow recess adapted to receive one of said plates 26, 27 and after insertion of the plate into said recesses the outer edges of the recesses are turned over to retain the plate in position.

A A lock formed as above described is very neat in appearance and can readily be mounted on a window or door by screws inserted into the apertures 15 and 16 in either of two alternative positions namely a position in which the end 28 of the housing as seen in Figure 1 engages the window or door to which the lock is secured or an alternative position in which the opposite end 29 of the housing 10 engages the window or door.

The position chosen of course will be the one which suits better the accessibility of the key slot and the positioning of the associated bolt keep which will be positioned on the co-acting window frame or door frame.

Furthermore instead of forming said knurled head 1 8 of the bolt integral with the remainder of the bolt a separately formed head which may be made of a synthetic resin or other frangible material can be mounted on the adjacent end of the bolt if desired in order to prevent an unauthorised person from inserting a tool behind the knurled head 1 8 in an endeavour to force the bolt into its inoperative position without using the key 23, the arrangement being such that if any similar attempt is made to force the bolt when the latter is provided with a synthetic resin head then such head would break off and thereby render the forcing of the bolt abortive.

In an alternative construction, instead of securing the plates 26 and 27 in the manner above described, each plate may be formed so that it is of bowed configuration when considered in a cross-section taken across its width, each plate then being forced into the corresponding housing recess by means of a press (whilst the adjacent portions of the ends of the housing are supported against "spreading") so that the plate is flattened and the longitudinal edges of the plate are forced into the material forming said adjacent portions of the ends of the housing.

Claims (7)

1. A lock which comprises a housing in a bore of which is mounted a slidable bolt which is movable relative to the housing between an operative locked position in which one of its ends projects from one side of said housing and an inoperative position in which said one end does not project or only projects by a small extent from said one side of the housing, said bolt being movable by resilient means from its operative position to its inoperative position when released from the operative position, there being also provided key-operable means which is mounted in a further bore in the housing which is parallel to said bore in which the bolt is mounted, the keyoperable means being connected to a bolt retaining member which is urged by further resilient means to engage and hold said bolt in its operative locked position and which is movable by operation of said key-operable means against the force exerted by said further resilient means to a position in which said first-mentioned resilient means will move the bolt to its inoperative position.

2. A lock as claimed in Claim 1 wherein said housing is formed so as to be initially open on each of two opposite sides, said open sides being subsequently closed respectively by a pair of apertured plates which are secured to the housing after assembly of the other parts of the lock has been effected.

3. A lock as claimed in either of the preceding claims wherein said bolt is formed with an annular groove into which said bolt retaining member projects when the bolt is in its operative position.

4. A lock as claimed in any one of the preceding claims wherein the head of the bolt is formed separately from the remainder of the bolt in a frangible material.

5. A lock as claimed in Claim 2 wherein each of said apertured plates is mounted in a shallow recess formed in the adjacent side of the housing, the outer edges of each recess then being turned over to retain the associated plate in position.

6. A lock as claimed in Claim 2 wherein each of said plates is initially of bowed configuration, each plate then being forced into a recess formed in the adjacent side of the housing by means of a pressing operation whilse the adjacent ends of the housing are supported against "spreading", so that the plate will be flattened to cause edge portions of the plate to be forced into the material of the housing adjacent said recess in order to retain the plate in position.

7. A lock substantially as hereinbefore described with reference to and as shown in the accompanying drawings.