WO2004065732A1

WO2004065732A1 - A lock and key

Info

Publication number: WO2004065732A1
Application number: PCT/GB2004/000202
Authority: WO
Inventors: Oleg Lisnovitch
Original assignee: Oleg Lisnovitch
Priority date: 2003-01-21
Filing date: 2004-01-19
Publication date: 2004-08-05

Abstract

A lock and key for a door is provided. The lock (30) comprises a latch member (36) operably moveable between first and second positions by rotation of a key (2), the key acting directly on the latch means or on a latch operating means, the lock having a keyway aperture (34) to permit insertion of a key into the lock and through which the axis of rotation of the key passes, the latch member or latch member operating means being radially spaced from the axis or rotation of the key by a distance that is equal or greater than the maximum distance between the center of rotation of the key and the periphery of the keyway. A key (2) that is suitable for use with the lock is also provided the key having a shank and a key bit member (6), the key bit member being movable between a first position in which it is substantially axially aligned with the shank and a second position in which a portion of the key bit member projects laterally from the shank.

Description

A LOCK AND KEY

The present invention relates to a key and lock mechanism, in particular a key for a tumbler or lever lock type mechanism.

Conventionally simple tumbler or lever operated locks or latches are operated with a key that has a key bit projecting laterally from the key shank. Rotation of the key in the lock brings causes the key bit to move the bolt or latch between the locked and unlocked position by either acting directly on the latch or bolt or via a latch operating means such as one or more levers or tumblers .

Whilst such locks are simple to manufacture and fit to a door and are robust, one problem is that generally the latch or latch operating mechanism must be located sufficiently close to the keyway that it can be operated by the laterally projecting key bit which can leave such locks vulnerable to being picked by inserting picks or other tools through the relatively large keyway.

The present invention overcomes this problem by use of a key lock in which the latch or latch operating means is spaced away from the keyway. Accordingly in a first aspect the invention provides a lock for a door comprising a latch member operably moveable between first and second positions by rotation of a key, the key acting directly on the latch means or on a latch operating means, the lock having a keyway aperture to permit insertion of a key into the lock and through which the axis of rotation of the key passes, the latch member or latch member operating means being radially spaced from the axis or rotation of the key by a distance that is equal or greater than the maximum distance between the center of rotation of the key and the periphery of the keyway

The lock may be arranged such that the key acts directly to move the bolt or latch on rotation of the key. Alternatively a latch operating means may be provided, e.g. one or more tumblers or levers, that act to move the bolt or latch between the locked and unlocked position when actuated by rotation of the key.

The lock may be provided with one or more wards in the form of pins or rings located on the backplate of the lock or on a separate plate and which act to prevent rotation of a key which does not have corresponding grooves in one or both sides of the key bit .

In another aspect the invention features a key comprising a shank and having a moveable key bit member mounted on the shank, the key bit member being movable between a first position in which it is substantially axially aligned with the shank and a second position in which a portion of the key bit member projects laterally from the shank .

The key bit is generally in the form of an elongate plate pivotally mounted on the key shank so that in its closed position the key bit lies substantially along the axis of the key shank and preferably does not project substantially laterally of the key shank.

The key bit may be mounted at any point along that part of the key shank that is inside the lock when he key is inserted in the lock. The key bit may be mounted in a cutaway section provided in the key shank or in a slot in the key shank. Preferably the key bit is mounted in a slot at or adjacent the distal end of the key shank.

Preferably the key bit and the key shank are provided with complementary stop means to restrain complete rotation of the key bit. For example, complementary cutaway sections in the key shank and an end of the key bit can be provided.

On insertion of the key into a lock rotation of the key causes the key bit to fall to the open position. The key bit may be biased, e.g. by weighting the key bit at one edge and towards the end of the bit, so that on rotation of the key by approximately 180 degrees from the operating position the key bit will tend fall back to the closed position.

The key bit is provided with cutouts at one or both ends of the bit that correspond to cutouts provided on the latch or bolt or that engage with tumblers or levers when the key is rotated to move the latch or bolt from the locked to unlocked position.

The key bit may also be provided with cutaway sections along one or both of the sides of the bit that cooperate with wards located on the backplate of the lock or on a separate plate and which act to prevent rotation of a key in the lock which does not have the appropriately positioned cutaway sections. The invention will now be illustrated with reference to the following drawings in which:

Fig 1 shows a key according to the present invention.

Fig 2 shows a partial section through the end of the key of Fig 1.

Fig 3 shows a partial section through the key of Fig 1 showing detail of key bit stop means .

Fig 4 shows a schematic partial section of a lock according to a first embodiment of the present invention.

Fig 5 shows a schematic view of a lock according to a first embodiment of the present invention.

Figs 6 to 8 show schematic partial sections of a lock according to a second embodiment of the present invention.

Figs 9 to 15 show exploded views of the lock components of Figs 6 to 8.

Referring to Fig. 1 there is shown a key 2 according to the present invention in which the key bit member 6 is pivotally mounted through rivet 8 to the key shank 4. The key bit has a first end 10 including a cutaway 18 and a second end 12 and cutaway 20. The side 16 of the key member 16 is also provided with a cutaway section. The end 10 in some embodiments can also be provided with further cutaways 11. As shown in Figs 2 and 3 the key bit 6 is pivotally mounted in a slot 24 through rivet 8. The end face 26 of the slot 24 is angled at approximately 45 degrees such that the end 12 of the key bit rests on the end face.

Referring Figs 4 and 5, there is shown a lock 30 according to the present invention. The lock 30 comprises a backplate 32 having an annular key passage 34. A moveable latch bar 36 is supported by guide members 38. The latch bar has a number of notches 42 provided on the lower edge of the latch bar that can be engaged by latch stop 44 to lock movement of the latch bar. The latch stop 44 is attached to slide member 46 which is moveable about the pins 48 and 50 connected to the backplate which run in slots 52 and 54 provided in the slide. The latch stop 44 is held in engagement with the notches 42 in the latch bar by the action on the slide 46 of a spring 56 located behind cover plate 58.

In use a key 2 would be inserted into the lock through annular key passage 34 such that the face 16 of the key bit is facing substantially upward and the end 12 of the key bit is arrested against the end face 26 of the key bit slot 24.

Rotation of the key through approximately 180 degrees causes the key bit 6 to fall to the operating position in which the key bit projects laterally from the key shank 4. Further rotation of the key then brings the end 10 of the key bit into contact with the latch member 36 and the top edge of the slide 60. A cutaway section 66 is provided in the latch which cooperates with the cutaway 18 on the bit to prevent operation by an incorrect key. Continued rotation of the key moves the slide down against the action of the spring and disengages the latch stop from the latch bar and moves the latch 36 from the closed to the open position further rotation- then disengages the bit from the latch and slide member. The action of the spring 60 on the slide brings the latch stop into engagement with one of the notches in the latch bar to lock the latch in position.

Rotation of the key to bring it into position such that the end 10 of the bit 6 is facing in a substantially upward direction then causes the key bit to fall back into the closed position so that the key can be withdrawn. The key bit can be weighted on the end and side to bias the bit toward falling into the closed position.

The latch bar 36 can be moved without the key from the inside by pulling down on the latch stop 46 to disengage it from the latch bar and moving the latch bar with the handle 64. Alternatively the latch bar can may comprise two or more latch bar members each being moveable separately and bars having differing cutaway sections and corresponding cutouts on the key bit.

The lock also has a ward pin 39 located on the backplate 40 and a corresponding slot 22 in the side face 16 of the key bit which prevents rotation of an incorrect key inserted in the lock.

Another embodiment of the lock is shown in Figs 6 to 14, which provides increased security and allows for increased key variation so as to meet modern security requirements. In this embodiment, a number of plates 80, typically 3 to 5 or more plates are provided between the backplate 32 and the latch bar 36. Each plate is provided with a number of detents 82 & 84 along the uppermost edge. A pin 65 is mounted on, and extends through, the latch bar and engages in the detents on the upper edge of the plates. The plates are restrained from lateral movement by stops 63 but are moveable vertically. The plates are held in engagement with the pin 65 by spring 62.

The plates are provided with various cutout sections on the upper edge that correspond with cutout sections 11 provided on the end face of the key 10. The plates can also be arranged so that the upper edges are at different heights. The lock operates substantially as previously described but the end face of the key and the cutouts 11 also engage with the corresponding cutouts on the upper edge of the plates so that rotation of the key moves the plates downwardly against the spring 62 sufficiently to disengage the pin 65 from the detents in the upper edge of the plate. Further rotation of the key then moves the latch bar across to the locked position. The pin 65 is brought into alignment with further detents provided on the upper edge of the plates and the key disengages from the plates which are then brought into engagement with the pin 65 by spring 62 to lock, the latch bar.

The movable bit of the key means that the lock bolt or the tumblers etc of the lock do not need to be closely adjacent to the keyhole so that the lock mechanism is not accessible to tools inserted into the keyhole. In addition the narrow key passage also makes it difficult to insert picks or other tools into the lock and manipulate them so as to be able to operate the mechanism.

Additional security may be provided by provision of one or more pins that partially project into the key passage, corresponding grooves are provided in the key shank so that the key can only be fully inserted in the key passage when the grooves in the key shank are correctly aligned with the pins in the key passage. One or more circumferential grooves can be provided in the key shank to permit rotation of the key to operate the lock.

Claims

1. A lock for a door comprising a latch member opperably moveable between first and second positions by rotation of a key, the key acting directly on the latch means or on a latch operating means, the lock having a keyway aperture to permit insertion of a key into the lock and through which the axis of rotation of the key passes, the latch member or latch member operating means being radially spaced from the axis or rotation of the key by a distance that is equal or greater than the maximum distance between the center of rotation of the key and the periphery of the keyway.

2. A lock according to claim 1 wherein the keyway is substantially annular.

3. A lock according to claim 1 further comprising a means operable by the key to lock the latch member in said first and or said second position.

4. A lock according to claim 3 wherein said means comprises a latch stop member reversibly engageable with cooperating means provided on the latch member.

5. A lock according to claim 4 wherein the cooperating means comprises one or more detents on the latch member.

6. A lock according to claim 3 wherein said means comprises one or more plates reversibly engagable with co-operating means provided on the latch member.

7. A lock according to claim 6 wherein the cooperating means comprises one or more detents provided along an edge of the plates.

8. A lock according to claim 6 or claim 7 wherein the co-operating means comprises a locking pin located on the latch member.

9. A lock according to any of claims 1 to 5 further comprising one or more wards.

10. A key comprising a shank and having a key bit member, the key bit member being movable between a first position in which it is substantially axially aligned with the shank and a second position in which a portion of the key bit member projects laterally from the shank.

11. A key according to claim 10 wherein the key bit is pivotally mounted on the shank.

12. A key according to claim 10 or claim 11 wherein the key bit member is mounted at the distal end of the shank .

13. A key according to any of claims 10 to 12 wherein the key bit member is mounted in a slot in the key shank.

14. A key according to any of claims 10 to 13 wherein there are provided cooperating stop means between the key shank and key bit to prevent rotation of the bit.

15. A key according to claim 14 wherein the bit is mounted in a slot in the key shank and the rear face of the slot is angled to arrest an end of the bit.

16. A key according to any of claims 10 to 15 wherein a portion of the key bit member projects laterally from two sides of the shank when the key bit member is in said second position.

17. A key according to any of claims 10 to 16 wherein the key bit is provided with one or more slots in a side of the key bit.

18. A key according to any of claims 10 to 17 wherein on or both ends of the key bit are provided with a plurality of cutaway sections to cooperate with one or more tumblers or levers.

19. A lock and key comprising a lock according to any of claims 1 to 9 and a key according to any of claims 10 to 18.

20. A key as hereinbefore described with reference to the accompanying drawings .

21. A lock as hereinbefore described with reference to the accompanying drawings .