LOCK AND KEY THEREFOR

Abstract

A lock cylinder having a barrel and a lock housing, the barrel having a locking cam pivotally mounted therein, the locking cam including at least one recess on an outer periphery thereof, a housing recess formed on an inner wall of the lock housing, a locking member that, in a locking position, is positioned at least partly in the housing recess formed on the inner wall of the lock housing, the at least one recess on the locking cam including a first recess on the locking cam, the first recess being sized to enable the locking member to move out of the housing groove, the barrel having a key slot for receiving a key, the key including a projection for causing the locking cam to rotate to bring the first recess on the locking cam adjacent to or into alignment with the locking member such that the locking member moves out of the housing recess and into the first recess of the locking cam and barrel slot to thereby enable rotation of the barrel in the lock housing.

Claims

1-20. (canceled)

21. A lock cylinder comprising: a barrel having a locking cam pivotally mounted therein, the locking cam including at least one recess on an outer periphery thereof, and an opening or a hole through which a mounting pin extends such that the locking cam pivots about the mounting pin; a lock housing including a housing recess formed on an inner wall of the lock housing; a bearing that bears upon the locking cam; and a locking member that, in a locking position, is positioned at least partly in the housing recess formed on the inner wall of the lock housing; wherein the at least one recess on the locking cam including a first recess on the locking cam, the first recess being sized to enable the locking member to move out of the housing recess; wherein the barrel having a key slot for receiving a key, the key including a projection, the bearing being configured for contacting with the projection of the key to thereby cause the locking cam to rotate to bring the first recess on the locking cam adjacent to or into alignment with the locking member such that the locking member moves out of the housing recess and into the first recess of the locking cam to thereby enable rotation of the barrel in the lock housing.

22. The lock cylinder of claim 21, wherein the locking cam is biased towards the locking position.

23. The lock cylinder of claim 22 further comprising a biasing means located between the locking cam and an inner part of the barrel.

24. The lock cylinder of claim 21, wherein the locking cam comprises the first recess and a second recess that is shallower than the first recess such that the second recess is sized to only partly receive the locking member.

25. The lock cylinder of claim 24, wherein the first recess is larger than the second recess on the locking cam and the first recess is located below the second recess.

26. The lock cylinder of claim 25, wherein the locking cam is arranged such that when the locking cam is oriented with the second recess being generally aligned with the housing recess, the locking member is retained within the housing recess.

27. The lock cylinder of claim 26, wherein the locking member is located partly within the housing recess and partly within the second recess of the locking cam when the locking member is in the locked position.

28. The lock cylinder of claim 21, wherein the locking member comprises a bar and the housing recess comprises a groove that extends generally parallel to a longitudinal axis of the housing or barrel.

29. The lock cylinder of claim 21, wherein the projection of the key contacts the bearing during insertion of the key into the key slot to thereby cause rotation of the locking cam.

30. The lock cylinder of claim 29, wherein the bearing is a ball bearing.

31. The lock cylinder of claim 21 further comprising a blocking cam pivotally mounted within the barrel, the blocking cam including at least one blocking cam recess on a periphery thereof, the at least one blocking cam recess including a first blocking cam recess, the first blocking cam recess being sized to enable the locking member to move out of the housing groove, the blocking cam being movable between a blocking cam locking position and an blocking cam unlocked position, the blocking cam being arranged such that the projection on the key causes the blocking cam to pivot or rotate during insertion of the key, wherein the projection on the key includes a recessed region that, when the key is properly inserted, is located in alignment with the blocking cam such that the blocking cam is in the blocking cam unlocked position, and wherein if a key having a different projection or a lock picking element is inserted into the key slot, the blocking cam is caused to pivot by the projection or the lock picking element so that the blocking cam is moved to the blocking cam locking position.

32. The lock cylinder of claim 31, wherein the blocking cam is biased to the blocking cam unlocked position.

33. The lock cylinder of claim 31, wherein the blocking cam comprises the blocking cam first recess and a blocking cam second recess that is shallower than the blocking cam first recess such that the second recess is sized to only partly receive the locking member.

34. The lock cylinder of claim 31, wherein the blocking cam first recess is located above the blocking cam second recess in the blocking cam.

35. The lock cylinder of claim 31, wherein the blocking cam is mounted by a pivot pin extending through an opening in the blocking cam.

36. The lock cylinder of claim 31, wherein the blocking cam is mounted in a transverse slot formed in the barrel and the locking cam is mounted in a transverse slot formed in the barrel.

37. The lock cylinder of claim 31, wherein the barrel is provided with a longitudinal slot to accommodate the locking member when the locking cam and the blocking cam are in the unlocked position.

38. The lock cylinder of claim 21, wherein the projection comprises a lateral projection or a wing on the key.

39. The lock cylinder of claim 21, wherein the lock cylinder comprises a plurality of locking cams.

40. The lock cylinder of claim 21, wherein the lock cylinder is of the pin and tumbler type.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0049] Various embodiments of the invention will be described with reference to the following drawings, in which:

[0050] FIG. 1 shows a perspective view of a lock housing in accordance with an embodiment of the present invention;

[0051] FIG. 2 shows a perspective view of a lock barrel in accordance with one embodiment of the present invention;

[0052] FIG. 3 shows a front cross sectional view of a lock cylinder in accordance with the present invention, with a locking cam being shown in a locked position;

[0053] FIG. 4 shows a front cross sectional view that is similar to that shown in FIG. 3, but with the locking cam in an unlocked position;

[0054] FIG. 5 is an enlarged view of the lock barrel and locking cam as shown in FIG. 4;

[0055] FIG. 6 shows a front cross sectional view of a lock cylinder in accordance with the present invention, with a blocking cam being shown in an unlocked position;

[0056] FIG. 7 shows a front cross sectional view that is similar to that shown in FIG. 6, but with the blocking cam in a locked position; and

[0057] FIG. 8 shows an enlarged view of the lock barrel and blocking cam as shown in FIG. 6.

DESCRIPTION OF EMBODIMENTS

[0058] It will be appreciated that the drawings have been provided for the purposes of illustrating preferred embodiments of the present invention. Therefore, it will be understood that the present invention should not be considered to be limited solely to the features as shown in the attached drawings.

[0059] FIG. 1 shows a lock housing 1. The lock cylinder 1 has a bore 2 formed therein and a lock barrel 14 (see FIG. 2) is fitted into the bore 2 in the lock housing 1. A locking mechanism, generally denoted at 3, is actuated by rotation of the barrel 14. The locking mechanism may be of conventional design and need not be described further. The skilled person will appreciate that the locking mechanism 3 operates a latch, a locking bolt or the like which is used to lock a door or a gate, etc. As can be seen from FIG. 2, the barrel 14 includes a key slot 18. The key slot 18 has an opening in the front face 19 of the barrel 14.

[0060] The barrel 14 is shown in FIG. 2. The barrel 14 includes six spaced bores 20, 22, 24, 26, 28, 30. These bores come into alignment with a corresponding series of six bores 4, 5, 6, 7, 8, 9 that are formed in the lock housing 1 (as shown in FIG. 3). The upper ends of the bores 4-9 in the housing 1 are closed by appropriate plugs, one of which is shown at 10 in FIG. 3. The bores each hold a bore pin 32 and a housing pin 34. A shear junction or shear point 36 exists at the point of contact between the bore pin 32 and the housing pin 34. A spring 38 biases the pins 32, 34 inwardly towards the bore 14. This arrangement of bores and pins is conventional in pin and tumbler locks and it need not be described further.

[0061] The barrel 14 shown in FIG. 2 includes a longitudinal slot 40 machined into one side of the barrel to accommodate the locking member 60. A plurality of transverse extending slots (in this case, 3 transverse slots) 42, 44, 46 are also machined into the barrel 14, with the transverse slots 42, 44, 46 intersecting the longitudinal slot 40. Locking cams, one of which is shown at 48, are inserted into two of the transverse slots 44, 46. A blocking cam is inserted into the remaining transverse slot 42. A locking member 60, in the form of a cylindrical bar 60, is also positioned in the longitudinal slot 40.

[0062] Although not shown in FIG. 2, a bore is drilled into the barrel 14 from the rear face of the barrel towards the front face of the barrel. A pivot pin is inserted through this bore and the pivot pin is used to pivotally mount the locking cams and blocking cam in their respective transverse slots. This will be described in more detail hereunder.

[0063] FIGS. 3 to 5 show a cross sectional view taken along line A in FIGS. 1 and 2. FIG. 3 shows the locking cam being in a locked position whilst FIGS. 4 and 5 show the locking cam in the unlocked position.

[0064] As best shown in FIG. 5, locking cam 48 has a first peripheral surface 52 and a second peripheral surface 54. A first recess 56 and a second recess 58 are located between the first peripheral surface 52 and the second peripheral surface 54. As can be seen from FIGS. 3 to 5, the first recess 56 is significantly deeper than the second recess 58. As a result, a locking member, in the form of a cylindrical bar 60, can be fully received in the first recess 56.

[0065] The inner wall of the bore 2 of the housing 1 has a housing recess 62 in the form of a groove machined into the inner wall of the bore 2. The cylindrical groove 62 has a diameter that is just slightly larger than the diameter of cylindrical bar 60 such that about half of the cylindrical bar 60 can fit into the cylindrical groove 62.

[0066] The second recess 58 of the locking cam 48 is significantly less deep than the first recess 56. As a result, although the second recess has a surface that is complementary to the surface of the cylindrical bar 60, when the cylindrical bar 60 is received in the second recess 58, the cylindrical bar 60 protrudes out of the second recess 58 to a large extent. In this manner, when the second recess is in alignment with the housing groove 62, the cylindrical bar 60 extends from the second recess 58 into the housing groove 62.

[0067] The locking cam 48 also includes an opening 64 through which a pivot pin can extend. A biasing spring 66 biases the locking cam in a clockwise direction (as shown with reference to the orientation shown in FIGS. 3 to 5), such that the first peripheral surface 52 is biased towards the wall of the bore 2. The locking cam 48 also includes a lower inner surface 68 that is in contact with a ball bearing 70. Due to the locking cam 48 being biased by spring 66 in a clockwise direction, the surface 68 of the locking cam 48 remains in contact with the ball bearing 70.

[0068] FIG. 3 shows the locking cam 48 in a locked position, in which the barrel is locked against rotation relative to the housing. As shown in FIG. 3, the locking member/cylindrical bar 60 is seated in housing recess/cylindrical groove 62. The locking member 60 is also seated in the second recess 58. As a result, the locking member 60 prevents rotation of the barrel relative to the housing.

[0069] FIGS. 4 and 5 show insertion of a key 72 having a wing 74 extending laterally from the shank. When the key 72 is inserted into the key slot of the barrel, the wing 74 comes into contact with the ball bearing 70 and drives the ball bearing 70 to the right (as shown in FIG. 4). This causes the locking cam 48 to pivot about the pivot pin extending through opening 64. As a result, the locking cam 48 rotates in an anticlockwise direction. This moves the locking cam 48 such that the deeper first recess 56 comes into alignment with the locking member 60. Due to the larger depth of the first recess 56, the locking member 60 can move into the first recess 60 and move out of the housing recess 62. This is shown in FIGS. 4 and 5. As a result of this movement, the locking member 60 no longer interacts with the locking groove 62 and the locking member 60 no longer locks the barrel 14 against rotation relative to the housing 1. Consequently, the key (which is also operating the pins 32, 34) can be turned to cause the barrel 14 to also turn.

[0070] When the key 70 is removed from the key slot, the wing 74 is no longer acting on the ball bearing 70. As a result, the spring 66 causes the locking cam 48 to rotate in a clockwise direction, which brings the shallow second recess 58 back into contact with the locking member 60. As the locking cam 48 rotates in a clockwise direction as the key is pulled out, the lower edge of the housing recess 62 contacts the locking member 60 and stops further downward movement of the locking member 60. Continued rotation of the locking cam in a clockwise direction brings the second recess 58 adjacent to the locking bar 60 and this physically retains the locking bar 60 in the space defined by the housing groove 62 and the second recess 58. This stops relative rotation between the barrel 14 and the housing 1. The locking cam 48 reverts to the orientation shown in FIG. 3 when the key 70 is withdrawn.

[0071] In order to avoid the possibility of having someone with a key that operates the pins 32, 34 but without a wing 72 from also operating the lock by inserting a piece of wire or a lock picking element adjacent to the key to force the locking cam to move to the orientation shown in FIGS. 4 and 5, the barrel 14 may also be provided with one or more blocking cams, as shown in FIGS. 6 to 8. The blocking cam 80 includes a first peripheral surface 82 and a second peripheral surface 84. The blocking cam 82 also includes a first recess 86 and a second recess 88. Unlike the locking cam, in which the first recess 56 is located below the second recess 58, in the blocking cam 80, the first recess 86 is located above the second recess 88. Apart from this difference, the blocking cam 80 is similar to the locking cam 48. The blocking cam 80 is also pivotally mounted in the barrel 14 about a pivot pin that extends through opening 90 and a biasing spring 92 biases the blocking cam in a clockwise direction. A ball bearing 94 contacts a lower surface of the blocking cam 80 and the key 70.

[0072] In order to operate a lock having the blocking cam arrangement shown in FIGS. 6 to 8, it is necessary to use a key that has a laterally extending wing 74 that also has recesses cut into the laterally extending wing at a position where the ball bearing 94 or blocking cam 80 is located.

[0073] FIG. 7 shows the blocking cam 80 in a locked position. If a key having a lateral wing 74 that does not have a correctly positioned recess is inserted into the key slot of the barrel 14, the wing 74 causes the blocking cam 80 to rotate in an anticlockwise direction, which brings the shallow second recess 88 into alignment with the locking bar 60 and the housing groove 62. As a result, the locking member 60 is physically held between the housing groove 62 and the first recess 88. This locks the barrel 14 against rotation relative to the housing 1. It will be appreciated that the blocking cam will also be pushed into a locked position if a piece of wire or a lock picking element is inserted alongside a key if an attempt was made to pick the lock.

[0074] If the key with a properly cut recess in the wing 72 is used, the wing does not act on the ball bearing 94 and the biasing spring 92 biases the blocking cam 80 in a clockwise direction to the position shown in FIGS. 6 and 8. In this position, the deeper first recess 86 is in alignment with the locking member 60, which enables the locking member 60 to move out of the housing recess 62. As a result, the locking member 60 no longer locks the barrel 14 against rotation relative to the housing 1.

[0075] The key 70 may be provided with one or more recesses in the projection 72 in a manner that is similar to that as shown in FIG. 8 of Australian patent number 666369.

[0076] In the embodiment shown in the attached figures, the barrel 14 is fitted with two locking cams and one blocking cam. It will be appreciated that the number of locking cams and blocking cams may vary. Further, the position of the locking cams and blocking cams may also vary. In one embodiment, the locking cams are positioned in slots 42 and 46 and the blocking cam in slot 44. In another embodiment, the locking cams are positioned in slots 42 and 44 and the blocking cam in slot 46. In another embodiment the locking cams are positioned in slots 44 and 46 and the blocking cam is positioned in slot 42.

[0077] In embodiments of the present invention, the locking cams are biased to the locked position and the blocking cams are biased to the unlocked position.

[0078] The lock cylinder of the present invention provides a lock cylinder of enhanced security. The lock cylinder is desirably suitable for use with a C4 key or similar profile having an additional lateral projection or wing extending along a side thereof. In some embodiments, locking arms may provided on both sides of the key slot and the key maybe provided with projections or wings on both sides of the key shank. The key slot suitably includes an opening that is of complementary shape to keys having the desired projections or wings thereon. The lock cylinder may be provided with one or more locking cams. In the embodiment shown in the attached figures, the lock cylinder is provided with two locking cams.

[0079] Locks cylinders in accordance with the present invention allow lock systems to be implemented in which some locks have lock cylinders in accordance with the present invention and other locks have lock cylinders without the locking cams. In such systems, a superintendent may have a restricted key with the lateral projection or wing in order to provide master key access to a number of locks. However, an occupant may be provided with a lock that does not have a locking cam and a non-restricted key that does not include the lateral projection or wing. The occupant's key can operate, for example, the front door of the unit that is equipped with a lock without the locking cams. However, the occupants key cannot operate a secure lock that is fitted with the locking cams, such as a lock fitted to an enclosure housing electrical meters or equipment. However, the superintendent will have a key that has the projection or wing and this enables the superintendent to operate both the lock to the occupant's unit and the lock to the enclosure housing electrical meters or equipment.

[0080] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases in one embodiment or in an embodiment in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0081] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.