GB1581095A

GB1581095A - Lock with two key-receiving members

Info

Publication number: GB1581095A
Application number: GB611678A
Authority: GB
Original assignee: Lowe and Fletcher Ltd
Current assignee: Lowe and Fletcher Ltd
Priority date: 1978-02-16
Filing date: 1978-02-16
Publication date: 1980-12-10

Description

(54) NEW OR IMPROVED LOCK WITH TWO KEY-RECEIVING MEMBERS (71) We, LOWE & FLETCHER LIMITED, a British Company of Fryers Road, Leamore, Walsall, West Midlands, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a lock of the kind, hereinafter called the kind specified, having a body and two key-receiving members which are mounted in the body and which are accessible one at each of two opposite ends of the body, both of the key-receiving members being adapted to control a common device which is associated with the lock in use and each key-receiving member being adapted to be freed for movement within the body by application to the member of a proper key.

According to the invention, there is provided a lock of the kind specified wherein the body comprises a plurality of parts fastened together by fastening means not accessible at the ends of the body and, during assembly of the lock, each key-receiving member is mounted in a respective one of the body parts, called herein an end part, by inserting the key-receiving member through an opening in the end part, which opening faces in the assembled lock, towards the other end part.

In a lock of the kind specified, each keyreceiving member is accessible through a further opening in the body, which further opening is adjacent to an end of the body.

Since, in a lock in accordance with the invention, the key-receiving members are not inserted into the body through these further openings, the lock can readily be arranged to prevent withdrawal of a key-receiving member from the body through one of the further openings, even when a substantial force is applied to the key-receiving member by use of a slide hammer or other means. A slide hammer is an implement used by unauthorised persons to remove key-receiving members from locks, the implement having a tapered, screw threaded portion which can be screwed into the key slot of the key-receiving member to attach the slide hammer securely to the key-receiving member. The implement further includes a rectilinear shank which is integral with the screw threaded portion and on which there is carried a slide.At the end of the shank remote from the screw threaded portion, there is a stop for arresting the slide and if the slide is moved rapidly along the shank into engagement with the stop, a substantial force is applied to the keyreceiving member.

The end parts of the body are preferably fastened to an intermediate part of the body and the connection between each end part and the intermediate part may include a respective spigot and socket, each spigot being parallel to but offset from the axes of the key-receiving members. With this arrangement, if an axially outwardly directed force is applied to one of the key-receiving members, the associated end part will be subjected to a turning moment about an axis which is transverse to the axis of the keyreceiving member and is offset therefrom.

This turning moment will tend to bend the spigot, rather than simply withdraw the spigot from its socket and this will result in a high resistance to withdrawal of the end part of the body from the intermediate part.

The invention will now be described, by way of example, with reference to the accompanying drawing wherein: Figure 1 shows a side elevation of a lock in accordance with the invention, certain parts being broken away, Figure 2 is a similar view on an enlarged scale with further parts broken away and Figure 3 shows an end elevation of the lock.

The lock illustrated in the accompanying drawing is intended for fitting in a cavity in a door or other structure for controlling a device (not shown) associated with the lock, for example a latch fitted to the door. The lock comprises a body 1, opposite end faces 2 and 3 of which are accessible at opposite faces of the door when the lock is fitted thereto.

Within the body 1 there are disposed two key-receiving members, 4 and 5 respectively, each of which is rotatable about a common axis 6 when a proper key is applied to the member. The member 4 is accessible at an opening 7 in the end face 2 of the body and has an elongate slot 8 extending along the axis 6 to receive a key. The member 5 is accessible at an opening 9 in the end face 3 of the body and has an elongate slot (not shown) similar to the slot 8 for receiving the key.

The lock further comprises a device 11 for controlling the associated door latch.

The device 11 is situated midway between the end faces 2 and 3 of the body and is rotatable about the axis 6, subject to the control of the key-receiving members 4 and 5.

These members have respective shaft portions 12 and 13 which extend into a central opening formed in the device 11 and the shaft portions have radial projections 14 which are engageable with abutments on the device 11 to enable torque to be transmitted between the device 11 and either one of the members 4 and 5. The control exercised over the device 11 by the members 4 and 5 may be driving and/or restraining of the device 11 by the key-receiving members. The arrangement may be such that both of the key-receiving members must be free for rotation before rotation of the device 11 is permitted but, more usually, the arrangement will be such that the device 11 can be rotated through a limited range of movement by either one of the members 4 and 5 whilst the other of these members is stationary.The device 11 may be in the form of a cam or the like for causing reciprocation of an associated element. Alternatively, the device 11 may be adapted in one rotary position to obstruct movement of an associated element and in a second rotary position to permit movement of the associated element.

The body comprises two end part 15 and 16 respectively on which the end faces 2 and 3 are formed, an intermediate part 17, a housing 18 for the key-receiving member 4 and a housing 19 for the key-receiving member 5.

Locking elements (not shown) are provided to constrain movement of the member 4 relative to the housing 18 when the key is absent from the member 4 and further locking elements are provided to constrain movement of the member 5 relative to the housing 19 when the key is absent from the member 5.

These locking elements may be disc or pin tumblers arranged in a known manner or magnetic locking elements arranged, for example, in the manner described in the complete specification of our co-pending Applications Nos. 10416/76 and 11195/77, (Serial No. 1572091).

The opening 7 is non-circular and is defined by a flange 20 formed on the end part 15 of the body.

The housing 18 is situated in the end part 15, extends into the opening 7 and is constrained by the flange 20 against rotation relative to the bodyabout the axis. The housing 18 is formed with a shoulder 21 which is engaged with an axially inwardly facing surface of the flange. At its axially outer end, the housing 18 is formed with a flange 22 which defines an aperture through which the key can be inserted into the key slot 8.

An end face of the key-receiving member 4 abuts the axially inwardly facing surface of the flange 22 so that the flanges 22 and 20 together prevent withdrawl of the key receiving member 4 from the body 1 through the opening 7. Similar flanges 23 and 24 respectively are provided on the body end part 16 and on tne housing 19 to prevent withdrawl of the key-receiving member 5 from the body 1 through the opening 9.

A notch 25 is formed in the flange 22 to enable a radial projection on the key to pass the flange. When engaged behind the flange, this projection prevents withdrawal of the key until the projection is aligned with the notch 25 by appropriate rotation of the key.

The intermediate body part 17 lies between the end parts 15 and 16 but has respective spigots 26 and 27 which are received in sockets one of which is shown at 28 formed one in the end part 15 and the other in the end part 16. The spigots and sockets are of cylindrical form and have a common axis 30 which is parallel to the axis 6 but the spigots are offset laterally from the axis 6. In the intermediate part 17, there is formed a bore 31 which extends transversely of the axis 6.

This bore is intended to receive a pin (not shown) which extends into the bore from a free edge of a door in which the lock is fitted, the pin thereby constraining the lock body 1 against movement towards either face of the door.

The parts of the body are initially separate and are assembled in the following manner.

Firstly, each of the housings 18, 19 is assembled with the associated key-receiving member. The housing 18 and member 4 are then inserted together into the body end part 15 through an opening 32 remote from the opening 7. Similar, the housing 19 and member 5 are inserted into the body end part 16 through an opening remote from the opening 9. The spigot 26 is then inserted into the socket 28 and the device 11 is fitted on the shaft portion 12. With the sockets 28 and 29 in axial alignment with each other, and the key-receiving members 4 and 5 in axial alignment with each other the body end part 16 is then moved towards the end part 15 so that the spigot 27 enters its socket and the shaft portion 13 enters the central aperture of the device 11.

The body components are then fastened together by fastening elements on the form of pins 33 and 34 which are driven through apertures in respective ones of the end parts 15 and 16 into respective ones of the spigots 26 and 27. It will be understood that, when the lock is in use, these pins are situated in the interior of the door and are not accessible at the faces of the door.

It will also be understood that the intermediate part 17 of the body could be formed integrally with one of the end parts 15 and 16, if required, and that, with a suitable arrangement of locking elements, the housings 18 and 19 could be formed integrally with the end parts 15 and 16 respectively. Thus, the body 1 may comprise only two initially separate parts. However, it is preferred that the end parts 15 and 16 be identical with each other, as shown.

If, after the lock has been assembled, a force is applied to the member 4 tending to displace this member relative to the body 1 in a direction along the axis 6, the end part 15 will tend to pivot on the pin 33. A turning moment about the pin 33 will be applied to the end part 15 and this turning moment will be resisted by the spigot 26, which will be subjected to a bending load. This will result in friction between the part 15 and the spigot and therefore in a resistance to withdrawal of the member 4 and end part 15 which considerably exceeds the shear strength of the pin 33.

WHAT WE CLAIM IS: 1. A lock of the kind specified wherein the body comprises a plurality of parts fastened together by fastening means not accessible at the ends of the body and, during assembly of the lock, each key-receiving member is mounted in a respective one of the body parts, called herein an end part, by inserting the key-receiving member through an opening in the end part, which opening faces, in the assembled lock, towards the other end part.

2. A lock according to Claim 1 wherein he body includes an intermediate part to which each of the end parts is fastened.

3. A lock according to Claim 2 wherein each end part is connected to the intermediate part by a respective spigot and socket, the axis of each spigot being parallel to the axes of the key-receiving members.

4. A lock according to Claim 3 wherein the spigots are spaced from the axes of the key-receiving members.

5. A lock according to any preceding claim wherein the end parts are identical with each other.

6. A lock according to Claim 3 wherein there is formed in the intermediate part a bore which extends at right angles to the axes of the spigots.

7. A lock according to any preceding claim wherein each key-receiving member is mounted in a housing relative to which the key-receiving member is rotatable when the proper key is applied to the key-receiving member and the key-receiving member and housing are both inserted into the associated end part through the same opening in the end part.

8. A lock according to Claim 7 wherein each end part has, adjacent to an end of the body, an abutment which limits movement of the associated housing towards said end of the body and the housing has an abutment which limits movement of the key-receiving member towards said end of the body.

9. A lock of the kind specified having a body substantially as herein described with reference to and as shown in the accompanying drawings.

10. A lock substantially as herein described with reference to and as shown in the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. enters the central aperture of the device 11. The body components are then fastened together by fastening elements on the form of pins 33 and 34 which are driven through apertures in respective ones of the end parts 15 and 16 into respective ones of the spigots 26 and 27. It will be understood that, when the lock is in use, these pins are situated in the interior of the door and are not accessible at the faces of the door. It will also be understood that the intermediate part 17 of the body could be formed integrally with one of the end parts 15 and 16, if required, and that, with a suitable arrangement of locking elements, the housings 18 and 19 could be formed integrally with the end parts 15 and 16 respectively. Thus, the body 1 may comprise only two initially separate parts. However, it is preferred that the end parts 15 and 16 be identical with each other, as shown. If, after the lock has been assembled, a force is applied to the member 4 tending to displace this member relative to the body 1 in a direction along the axis 6, the end part 15 will tend to pivot on the pin 33. A turning moment about the pin 33 will be applied to the end part 15 and this turning moment will be resisted by the spigot 26, which will be subjected to a bending load. This will result in friction between the part 15 and the spigot and therefore in a resistance to withdrawal of the member 4 and end part 15 which considerably exceeds the shear strength of the pin 33. WHAT WE CLAIM IS:

1. A lock of the kind specified wherein the body comprises a plurality of parts fastened together by fastening means not accessible at the ends of the body and, during assembly of the lock, each key-receiving member is mounted in a respective one of the body parts, called herein an end part, by inserting the key-receiving member through an opening in the end part, which opening faces, in the assembled lock, towards the other end part.