GB2196511A - Lock for push-button telephones - Google Patents

Abstract

A lock for a push-button telephone comprises a hasp member (8) (Fig. 3) for securing to the surface of the telephone key-pad to surround at least part of a predetermined push-button of the key-pad whilst still permitting access to that push-button, a cover member (22) (Fig. 2) to encase the remaining push-buttons of the key-pad and having a recess therein to receive the hasp member (8) therethrough, and a locking device (28) mounted on the cover member (22) and including a bolt member (32) movable between an inoperative position remote from the hasp member (8) and an operative position co-operating with the hasp member (8) to prevent removal of the cover member (22) from the telephone. <IMAGE>

Description

SPECIFICATION Lock for push-button telephones This invention relates to locks for push-button telephones.

It is often necessary, in both industrial and domestic premises, to prevent unauthorised use of push-button telephones, and there are a variety of telephone key-pad covers and/or locks available for such purposes.

More particularly, these known arrangements commonly enclose all the push-buttons of the key pad and include a cover having an operative position secured to the body of the telephone or gripping one or more of the bushbuttons. Thus the telephone is completely deactivated when the lock is in position thereon.

There are, however, situations where even unauthorised personel should be in a position to be able to make use of the otherwise inaccessible key-pad of a telephone, for example in the case of an emergency requiring the presence of police, the fire service or the ambulance service, or in other situations internal of the premises where assistance can be gained by dialling a predetermined number.

It would therefore be desirable to be able to provide a lock for a push-button telephone which de-activated the telephone to unauthorised personel other than in predetermined situations of emergency or where assistance was required.

According to the present invention there is provided a lock for a push-button telephone, the lock comprising a hasp member adapted to be secured to the surface of the key-pad to surround part at least of a predetermined push-button of the key-pad whilst permitting access therethrough to said push-button, a cover member adapted to encase the remainder of the push-buttons and recessed to receive therethrough said hasp member, and a locking device mounted on the cover member, the locking device including a bolt member having an operative position co-operating with the hasp member to prevent removal of the cover member from the telephone.

It will be appreciated that, with such an arrangement, and with the lock in its operative position on the telephone, the predetermined push-button, conveniently the number 9 key, is always available for use in emergency or like situations, while the other push-buttons are totally inaccessible, thereby preventing unauthorised normal use of the telephone.

Conveniently the hasp member ccmprises a base portion having a rectangular aperture therethrough adapted to receive therein the predetermined push-button, and an upstanding abutment portion for co-operation with the bolt member of the locking device.

The base portion of the hasp member may have one or more further rectangular apertures therethrough adapted to receive therein one or more of the push-buttons adajcent said predetermined push-button.

Preferably the base portion of the hasp member is secured to the surface of the keypad of the telephone by means of an adhesive.

The cover member is conveniently of openbottomed shape including a top wall and depending sidewalls adapted to seat on the surface of the key-pad, the top wall and the sidewalls being recessed to receive therethrough the hasp member, the upper end of the abutment portion of the hasp member conveniently being flush with the upper surface of the top wall of the cover member.

The locking device is preferably key-operated and comprises ahousing mounted on the cover member, the bolt member being movable in the housing between an inoperative, retracted position remote from the abutment portion of the hasp member and an operative, extended position co-operating with the abut ment portion of the hasp member to prevent removal of the cover member from the telephone.

In a preferred embodiment of the invention, the abutment portion of the hasp member has a transversely extending slot formed therein adapted to receive the free end regions of the bolt member in its operative position to effect said co-operation between the locking device and the hasp member.

Conveniently the bolt member is resiliently biased into its operative position, movement of the bolt member from its operative position to its inoperative position preferably being effected by inserting the key into the locking device to release a locking mechanism reacting between the housing and the bolt member, the key and bolt member then being movable together relative to the housing against said resilient bias.

Although the hasp member and the cover member may be of a plastics material, it is preferred that said components, as well as the locking device, are of die-cast zinc.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig.1 shows part of a key-pad of a conventional pushbutton telephone; Fig. 2 is a perspective view of the cover member and locking device of a telephone lock according to the invention; Fig. 3 is a perspective view of the hasp member of a telephone lock according to the invention, and Fig. 4 is a partial vertical section through a telephone lock according to the invention.

Referring to the drawings, Fig. 1 shows a conventional key-pad, indicated generally at 2, of a push-button telephone, the key-pad including a surface 4 through which project push-buttons 6 numbered 0 to 9.

The telephone lock includes a hasp member shown in Fig. 3 and indicated generally at g, the hasp member 8 comprising a base portion 10 through which are formed a pair of rectangular-shaped apertures 12,14 and an opensided aperture 16. The sizes and spacings of the apertures 12,14,16 conform with those of the push-buttons 6 of the key-pad 2 for reasons which will become apparent.

The hasp member 8 further comprises an upstanding wall 18 beteen the apertures 12 and 14, said wall 18 having a transverse slot 20 formed in the side thereof adjacent the aperture 14, again for reasons which will be detailed below.

In the operative position of the illustrated hasp member 8, the base portion 10 is stuck to the surface 4 of the key-pad 2 by means of a strong adhesive with the number 9 pushbutton passing through the aperture 12 in the base portion 10, with the number 8 pushbutton passing through the aperture 14 in the base portion 10, and with the number 7 pushbutton passing through the aperture 16 in the base portion, depression of said push-buttons not being prevented by the presence of the hasp member 8.

The telephone lock further includes an openbottomed cover member indicated generally at 22 and comprising a top wall 24 and depending sidewalls 26. The cover member 22 is shaped to encase all the push-buttons 6 except the number 9 key, the top wall 24 and sidewalls 26 being recessed to receive therethrough the upstanding wall 18 of the hasp member, 8 and that part of the base portion 10 apertured at 12 and surrounding the number 9 push-button. With the cover member 22 in its operative position seating on the surface 4, the top of the wall 18 of the hasp member 8 is flush with the upper surface of the top wall 24 of the cover member 22.

Mounted on the cover member 22 is a keyoperated locking device indicated generally at 28 and including a locking bolt 32. The locking bolt 32 is resiliently biased to the operative position shown in Figs. 2 and 4 in which the free end regions of the bolt 32, which include a transverse end flange 34, project outwardly from the housing 30. Movement of the bolt 32 inwardly of the housing 30 from its operative position to a retracted inoperative position is prevented by means of a locking mechanism including spring-loaded locking pins mounted in the housing 30 and reacting between the housing 30 and the locking bolt 32.

Formed in the upper surface of the locking bolt 32 is a keyway 36 in which can be received the shaft 38 of an associated key indicated generally at 40, the arrangement being such that, on insertion of the shaft 38 of the key 40 into the keyway 36 of the bolt 32, the locking pins are urged by the shaft 38 of the key 40 from their locking positions to permit inward movement of the bolt 32 relative to the housing 30. This movement is effected by urging the key inwardly relative to the housing 30 to move the bolt 32 therewith against said resilient bias.

On release of the key, the bolt 32 and key 40 are returned by the resilient bias to the operative position of the bolt 32 shown in the drawings.

The described lock operates as follows.

The hasp member 8 is glued into its permanent operative position on the surface 4 of the key-pad 2 with the number 9 push-button projecting through the aperture 12 in the base portion 10 of the hasp member.

The key 40 is inserted into the keyway 36 in the bolt 32, and the cover member 22 and locking device 28 are located over the remaining push-buttons 6 with the upstanding wall 18 projecting through the recess in the cover member 22. The key 40 is pushed inwardly of the housing 30 to urge the bolt 32 into its retracted, inoperative position whereby the cover member 22 can be lowered into its operative position with the sidewalls 26 engaging the surface 4 of the key-pad 2, the transverse flange 34 on the locking bolt 32 in this inoperative position of the bolt being located to one side of, and out of engagement with, the upstanding wall 18 of the hasp member.

The key 40 is then released and the locking bolt 32 is thus urged outwardly of the housing 30 into its operative position, in which position the end flange 34 on the bolt 32 is received within the transverse slot 20 in the upstanding wall 18 of the hasp member 8.

The key 40 is removed from the bolt 32 and the lock is in its operative position with the co-operation between the end flange 34 of the locking bolt 32 and the slot 20 of the hasp member 8 preventing removal of the cover 22 other than by use of the associated key 40.

Thus normal usage of the telephone is prevented, although emergency use, by way of dialling 999, can still be effected.

The head 42 of the key 40 is angled upwardly relative to the shaft 38 to avoid contact with the hasp member 8 on insertion and removal of the key into and from the keyway 36 and also to indicate the operative orientation of the key-the non-symmetrical nature of such a key adds to the security of the locking device.

Conveniently the hasp member 8, the cover member 22 and the locking device 28 are diecast from zinc, although other materials, such as plastics, could be used.

The base portion 10 of the hasp member 8 may be shaped to surround only the predetermined push-button 6, which may be other than the number 9 key, although the greater the area of contact of the hasp member 8 with the surface 4 of the key-pad 2, the more securely can the hasp member be located in its operative position.

in all cases it is to be emphasised that the presence of the hasp member 8 does not in any way detrimentally affect normal depression of the push-buttons 6. Indeed the permanent presence of the hasp member 8 around a predetermined push button when the cover member 22 is not in position on the telephone can have distinct advantages in that it positively defines the location of a predetermined push-button, for example the emergency number 9 key, which can be useful in the event of blackouts or for the non-sighted.

Claims (11)

1. A lock for a push-button telephone, the lock comprising a hasp member adapted to be secured to the surface of the key-pad of the telephone to surround part at least of a predetermined push-button of the key-pad whilst permitting access therethrough to said pushbutton, a cover member adapted to encase the remainder of the push-buttons and recessed to receive therethrough the hasp member, and a locking device mounted on the cover member, the locking device including a bolt member having an operative position cooperating with the hasp member to prevent removal of the cover member from the telephone.

2. A telephone lock as claimed in claim 1 which the hasp member comprises a base portion having a rectangular aperture therethrough adapted to receive therein the predetermined push-button, and an upstanding abutment portion for co-operation with the bolt member of the locking device.

3. A telephone lock as claimed in claim 2 in which the base portion of the hasp member has one or more further rectangular apertures therethrough adapted to receive therein one or more of the push-buttons adjacent said predetermined push-button.

4. A telephone lock as claimed in claim 2 or claim 3 in which the base portion of the hasp member is secured to the surface of the keypad of the telephone by means of an adhesive.

5. A telephone lock as claimed in any one of claims 2 to 4 in which the cover member is of open-bottomed shape and includes a top wall and depending sidewalls adapted to seat on the surface of the key-pad, the top wall and side-walls being recessed to receive therethrough the hasp member such that the upper end of the abutment portion of the hasp member is flush with the upper surface of the top wall of the cover member.

6. A telephone lock as claimed in any one of claims 2 to 5 in which the locking device is key-operated and comprises a housing mounted on the cover member, the bolt member being movable in the housing between an inoperative retracted position remote from the abutment portion of the hasp member and an extended, operative position cooperating with the abutment portion of the hasp member to prevent removal of the cover member from the telephone.

7. A telephone lock as claimed in claim 6 in which the abutment portion of the hasp member has a transversely extending slot formed therein adapted to receive the free end regions of the bolt member in its operative position to effect said co-operation between the locking device and the hasp member.

8. A telephone lock as claimed in claim 6 or claim 7 in which the bolt member is resiliently biased into its operative position.

9. A telephone lock as claimed in claim 8 in which movement of the bolt member from its operative position to its inoperative position is effected by inserting the key into the locking device to release a locking mechanism reacting between the housing and the bolt member, the key and bolt member then being movable together relative to the housing against said resilient bias.

10. A telephone lock as claimed in any one of claims 1 to 9 in which the hasp member, the cover member and the locking device comprise die-cast zinc.

11. A lock for a push-button telephone substantially as described with reference to and as illustrated by the accompanying drawings.