Lock cylinder and key

Abstract

A lock cylinder (10) is disclosed. The lock cylinder (10) comprises a barrel (12) rotatably mounted within a housing (11), a locking member (28) for controlling the position of a pin (22) within the barrel (12), and a movable magnetic element (26) for controlling the position of the locking member (28) with respect to the pin (22). The barrel (12) comprises a keyway (14) configured to receive a key (35) comprising a magnetic key element (351) and the pin (22) is configured to be moved by the key (35) to a shear line to enable the barrel (12) to be rotated with respect to the housing (11). The movable magnetic element (26) has a locked position in which the movable magnetic element (26) holds the locking member (28) in a position in which the locking member (28) prevents the pin (22) being moved to the shear line (S) and an unlocked position in which the pin (22) is movable to the shear line (S). The movable magnetic element (26) is configured to be moved from the locked position to the unlocked position by the magnetic key element (351) when the key (35) is inserted into the keyway (14). A key (35) for operating a lock cylinder (10) is also disclosed.

Description

Field of the Invention

[0001] The present invention concerns lock cylinders. More particularly, but not exclusively, this invention concerns a lock cylinder with improved security. The invention also concerns a key for operating the lock cylinder, and a kit of parts comprising a lock cylinder and a key.Background of the Invention

[0002] Lock cylinders are a fundamental component of locks used to protect property. Prior art lock cylinders, while providing security, may be vulnerable to a range of unauthorised access techniques, such as lock picking and bumping. These vulnerabilities are well-known and create a challenge for manufacturers to develop lock cylinders capable of withstanding sophisticated unauthorised access techniques.

[0003] Furthermore, the keys of many types of prior art lock cylinders can be easily copied. Therefore, even if a lock cylinder is provided with features intended to resist unauthorised access techniques, it may be possible to gain unauthorised access by obtaining a copy of the key. As such, there is a desire to control the ease with which a copy of a lock cylinder key can be obtained.

[0004] The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved lock cylinder and key for a lock cylinder.

[0005] WO 2014 / 005569 A2 discloses a lock cylinder wherein a magnet is provided in the cylinder core which can be displaced by a magnet arranged in the key, and can be brought into engagement with a spring-loaded ball-pin unit. The ball of said unit engages in a locking shaft groove of the cylinder housing when there is no key in the keyway. The magnet present in the key can withdraw the magnet in the cylinder core from the ball-pin unit, thereby disengaging it, when the key is in the keyway.

[0006] EP 2492421 A1 discloses a lock cylinder comprising an auxiliary locking pin which prevents complete insertion of a key into the lock cylinder. The auxiliary locking pin is moved when a magnet in the key is operated against the action of a magnet arranged in the lock cylinder.

[0007] CN 104179390 A and EP 2937495 A1 disclose further examples of lock cylinders configured to be operated by keys comprising magnets.Summary of the Invention

[0008] The present invention provides a lock cylinder comprising: a housing, a barrel rotatably mounted within the housing, a pin movably mounted within the barrel, a locking member for controlling the position of the pin within the barrel, and a movable magnetic element for controlling the position of the locking member with respect to the pin, wherein: the barrel comprises a keyway configured to receive a key comprising a magnetic element and the pin is configured to be moved by the key to a shear line to enable the barrel to be rotated with respect to the housing; the movable magnetic element has a locked position in which the movable magnetic element holds the locking member in a position in which the locking member prevents the pin being moved to the shear line; the movable magnetic element has an unlocked position in which the pin is movable to the shear line; and the movable magnetic element is configured to be moved from the locked position to the unlocked position by the magnetic key element when the key is inserted into the keyway.

[0009] The lock cylinder may be of the type referred to in the art as a "pin tumbler" lock cylinder. The pin may therefore be one of a plurality of pins which are configured to be moved to the shear line by the key when the key is inserted into the keyway to enable the barrel to be rotated with respect to the housing. The pin may be referred to herein as a "lockable pin". The other pins may not be prevented from being moved to the shear line by a locking member. The pins may be biased into the keyway by respective biasing members. The biasing members may be springs. The lock cylinder may be of the form generally referred to in the art as a "Euro profile" cylinder.

[0010] The lock cylinder according to the first aspect of the invention has a lockable pin which can be moved to the shear line only when a key comprising an appropriate magnetic key element is inserted into the keyway. Insertion of the correct key into the keyway causes the movable magnetic element to move to the unlocked position, which corresponds to a position in which the movable magnetic element no longer holds the locking member in the position in which the locking member prevents the pin being moved to the shear line. Therefore, even if the key has been cut with the correct shape to move the pin to the shear line, the lock cylinder cannot be operated unless the key has the appropriate magnetic key element. Furthermore, the lockable pin may reduce the susceptibility of the lock cylinder to picking and bumping attacks.

[0011] The lock cylinder may comprise a locking magnetic element. The movable magnetic element may be positioned on a first side of the keyway. The locking magnetic element may be positioned on an opposite second side of the keyway. The movable magnetic element may be held in the locked position by the magnetic attraction of the movable magnetic element to the locking magnetic element. For example, a magnetic north pole of the movable magnetic element may be oriented towards a magnetic south pole of the magnetic locking element (or the vice versa) such that the movable magnetic element is magnetically attracted to the locking magnetic element. In use, the first side of the keyway may be positioned below the keyway and the second side of the keyway may be positioned above the keyway.

[0012] The movable magnetic element may be configured to be moved from the unlocked position to the locked position by the magnetic attraction of the movable magnetic element to the locking magnetic element. In such embodiments the movable magnetic element may automatically return to the locked position when the key is removed from the keyway, regardless of the configuration of the key. However, in other embodiments, the movable magnetic element may be configured to return to the locked configuration by being magnetically attracted to an appropriate magnetic pole of the magnetic key element when an appropriately configured key is removed from the keyway.

[0013] The barrel may comprise a channel along which the locking member is movable. The pin may be located at a first end of the channel. When the movable magnetic element is in the locked position, the movable magnetic element may at least partially extend into an opposite second end of the channel to hold the locking member in the position in which the locking member prevents the pin being moved to the shear line. In the locked position of the movable magnetic element, the locking member may therefore be held in abutment with the pin by the movable magnetic element. The movable magnetic element may abut with the locking member on a first side of the locking member and the pin may abut with the locking member on an opposite second side of the locking member.

[0014] The movable magnetic element may comprise a first portion having a first width and a second portion having a second width. The second width may be less than the first width. In the locked position of the movable magnetic element, at least part of the first portion may extend into the channel. In the unlocked position of the movable magnetic element, at least part of the second portion of the movable magnetic element may extend into the channel. The width of the second portion may be such that the locking member does not restrict movement of the pin when the magnetic element is in the unlocked position. In the unlocked position of the movable magnetic element, the second portion of the magnetic element may increase the effective length of the channel and thereby enable the locking member to move away from the pin; the pin may push the locking member towards magnetic element.

[0015] The pin may comprise a shoulder. When the movable magnetic element is in the locked position, the locking member may be held in a position in which the locking member abuts with the shoulder of the pin to prevent the pin being moved to the shear line. The pin may comprise a first portion having a first width and a second portion comprising a second width and the shoulder is at the junction between the first portion and the second portion. The pin may comprise a waist where the width of the pin is locally reduced; in such arrangements the pin may comprise a first shoulder on a first side of the waist and a second shoulder on an opposite second side of the waist.

[0016] When the movable magnetic element is in the locked position, the locking member may hold the pin in a position in which the pin is spaced apart from a ceiling of the keyway. The position of the pin may be such that the pin is movable to the shear line by moving the pin closer to the ceiling of the keyway. The pin may be resiliently biased towards the ceiling of the keyway and, when the movable magnetic element is in the locked position, the pin can be moved against the resilient bias away from the ceiling of the keyway. This arrangement of the pin may permit a key to be fully inserted into the keyway because the key is able to move over the pin and move the pin against its resilient bias.

[0017] The barrel may define an axis. When the movable magnetic element is in the unlocked position, the locking member may be configured to move away from the pin in a direction perpendicular to the axis of the barrel. The direction of movement of the locking member may be substantially parallel with a width direction of the keyway. When the lock cylinder is in use, for example, installed within a door, the direction of movement of the locking member may be a substantially horizontal direction.

[0018] The pin may be configured to be moved along an axis to the shear line. The movable magnetic element may be movable between the locked position and the unlocked position in a direction parallel with the axis of movement of the pin.

[0019] The movable magnetic element may be contained within a channel. When the movable magnetic element is in the locked configuration the movable magnetic may element abuts a wall defining a first end of the channel. When the movable magnetic element is in the unlocked configuration, the movable magnetic element may abut a wall defining an opposite second end of the channel.

[0020] The locking member may be a ball. The ball may be spherical.

[0021] The keyway may have an elongate cross-section having a horizontal width which is greater than a vertical height of the cross-section. The pin may be located at a first position along the width of the keyway. The movable magnetic element may be located below the keyway. The movable magnetic element may be at a second position along the width of the keyway. The pin and the movable magnetic element may be spaced apart along the width of the keyway.

[0022] A blocking member may be provided in the keyway. The blocking member may be resiliently biased into the keyway. The blocking member may be resiliently biased by a spring. The blocking member may be biased into engagement with the pin. The blocking member may extend from the ceiling of the keyway. The blocking member may comprise a sloping cam surface. The sloping cam surface may face towards the entrance of the keyway. The blocking member may be configured to be lifted away from the pin by the key when the key is inserted into the keyway.

[0023] The lock cylinder may comprise one or more additional lockable pins which can be moved to the shear line only when a key comprising a suitable number of appropriate magnetic key elements is inserted into the keyway. Each additional lockable pin may be configured to be moved to the shear line in the manner described above in relation to the first lockable pin.

[0024] According to a second aspect, the present invention provides a key for the lock cylinder of the first aspect of the invention. The key comprises a blade. The blade comprises a recess configured to receive the pin of the lock cylinder and a magnetic key element arranged such that when the key is inserted into the keyway of the lock cylinder, the magnetic key element moves over the movable magnetic element and causes the movable magnetic element to move to the unlocked position.

[0025] The blade may have an elongate cross-section with a horizontal width which is greater than a vertical height of the cross-section. The magnetic key element may be spaced apart from the recess in the width direction of the blade such that when the key is inserted into the keyway of the lock cylinder, the magnetic key element moves over the movable magnetic element and causes the movable magnetic element to move to the unlocked position. The blade may comprise a plurality of recesses configured to receive other pins of the lock cylinder such that the key is configured to move all pins to the shear line. The recesses may be arranged along an axis parallel with a length direction of the blade. The blade may comprise a plurality of magnetic elements. The or each magnetic key element may be oriented with the magnetic poles of the magnetic key element arranged along a length direction of the key. The blade may comprise a corresponding plurality of recesses. Each recess may be configured to receive a lockable pin of the lock cylinder and each magnetic key element may be arranged such that when the key is inserted into the keyway of the lock cylinder, the magnetic key elements move over corresponding movable magnetic elements and cause the respective movable magnetic elements to move to respective unlocked positions.

[0026] According to a third aspect, the present invention provides a kit of parts comprising a lock cylinder according to the first aspect of the invention and a key comprising a magnetic key element, the key being configured such that the barrel of the lock cylinder can be rotated with respect to the housing when the key is inserted into the keyway. The key may be a key according to the second aspect of the invention.

[0027] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.Description of the Drawings

[0028] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: FIG. 1 shows a lock cylinder according to a first embodiment of the invention; FIG. 2 is a cross-sectional view of the external barrel of the lock cylinder with an incorrect key inserted in the keyway; FIG. 3 is a cross-sectional view along the keyway of the external barrel of the lock cylinder showing the movable magnetic element in a locked position; FIG. 4 corresponds to FIG. 3 but with the movable magnetic element in an unlocked position; FIG. 5 corresponds to FIG. 2 but with the correct key fully inserted into the keyway; FIG. 6 is a schematic drawing of a key configured to operate the lock cylinder of the first embodiment of the invention; FIG. 7 is a cross-sectional view of the external barrel of a lock cylinder according to a second embodiment of the invention with a first key partially inserted in the keyway; FIG. 8 corresponds to FIG. 7 but with the first key fully inserted into the keyway; FIG. 9 is a magnified view of the external barrel of the lock cylinder according to the second embodiment of the invention showing the movable magnetic element in a locked position; FIG. 10 corresponds to FIG. 9 but with the movable magnetic element in an unlocked position; FIG. 11 is a schematic drawing of the first key configured to operate the lock cylinder of the second or third embodiments of the invention; FIG. 12 is a schematic drawing of a second key configured to operate the lock cylinder of the second or third embodiments of the invention; FIG. 13 is a cross-sectional view of the external barrel of the lock cylinder according to the second embodiment of the invention with the second key fully inserted in the keyway; FIG. 14 is a cross-sectional view of the external barrel of a lock cylinder according to a third embodiment of the invention with the second key partially inserted in the keyway; FIG. 15 corresponds to FIG. 14 but with the second key fully inserted in the keyway; FIG. 16 shows the blocking member of a lock cylinder in accordance with a fourth embodiment of the invention; and FIG. 17 shows a key comprising a plurality of magnetic key elements configured to operate a lock cylinder in accordance with a further embodiment of the invention. Detailed Description

[0029] FIG. 1 shows a lock cylinder 10 according to a first embodiment of the invention. The lock cylinder 10 comprises an external barrel 12 and an internal barrel located within a cylinder housing 11. The external barrel 12 comprises a keyway 14 which is configured to receive a key for operating the lock cylinder 10. The cylinder housing 11 is a solid metal component in which the various moving components of the lock cylinder 10 are housed. The skilled person will appreciate that the terms "internal" and "external" do not necessarily mean that the lock cylinder is located with the external side outdoors and the internal side indoors, but that, when the lock cylinder is in use, for example when installed in a door, the internal side is the secured side of the lock cylinder 10 and the external side is the unsecured side. So, the external side may be exposed to the outdoors or may, for example, be positioned in an internal corridor of a building, and the internal side may be the inside of a room, or perhaps also exposed to the outdoors, but on the secure side of an external compound. In FIG. 1, the external side is to the left-hand side of the lock cylinder 10 and the internal side is to the right-hand side of the lock cylinder 10. The external side of the lock cylinder is described in detail below. The internal side of the lock cylinder 10 may be configured in substantially the same way as the external side of the lock cylinder 10, and thereby operable using the key that is used to operate the external side of the lock cylinder 10. In some embodiments, the internal side of the lock cylinder 10 may be configured in a different way to the external side of the lock cylinder 10. For example, the internal side of the lock cylinder 10 may comprise a thumb turn configured to operate the lock cylinder 10 from the internal side.

[0030] The lock cylinder 10 is configured to be inserted through a door leaf (not shown) with a suitably sized and shaped lock aperture, and the lock cylinder 10 is conventionally secured within the lock aperture via a bolt being screwed into hole 16 the cylinder housing 11. The presently described embodiment of the invention is of the type commonly referred to in the art as a "Euro profile" lock cylinder. However, in other embodiments of the invention, the lock cylinder may of course have a different shape.

[0031] The lock cylinder 10 includes a cam 18 which becomes engaged with the external lock barrel 12 when a suitable key has been inserted into the keyway 14 of the lock barrel 12, along the longitudinal axis X of the lock barrel 12. The cam 18 may be rotated about an axis parallel with the axis X between a position in which the cam 18 is housed within the external boundaries of the cylinder housing 11, and a position in which the cam 18 extends away from the external boundaries of the cylinder housing 11. The lock cylinder 10 will typically be received within a lock housing within a door and be configured such that rotation of the cam 18 causes the cam 18 to abut with a part of the lock housing that engages or disengages a latch, thereby locking or unlocking the door.

[0032] With reference to FIG. 2, the lock cylinder 10 comprises a series of pins 20, 22 which are arranged along the keyway 14 of the external lock barrel 12, parallel with the longitudinal axis X, and which extend into the keyway 14. The pins 20, 22 are biased into the keyway 14 by resiliently biasing members in the form of springs (which are not shown), with a secondary pin part 21 being positioned between each respective pin 20, 22 and each respective spring. The pins 20, 22 are configured to be engaged by a suitably shaped key to move the respective ends of the pins 20, 22 to a position S in which the ends of the pins 20, 22 are flush with an external surface of the external lock barrel 12; in this position of the pins 20, 22 the position S at which the ends of the pins are located is commonly referred to in the art as the "shear line".

[0033] When the respective ends of all of the pins 20, 22 are positioned at the shear line S, the external lock barrel 12 can be rotated within the cylinder housing 11 in order to operate the lock cylinder 10. However, when the ends of one or more of the pins 20, 22 are not positioned at the shear line, the external lock barrel is prevented from rotating by the one or more pins or the secondary pin parts 21 associated with the one or more pins bridging the interface between the external lock barrel 12 and the cylinder housing 11. The arrangement of the pins 20 is conventional and will be well understood by a skilled person, so no further description will be provided.

[0034] In accordance with the present invention, the lock cylinder 10 comprises a lockable pin 22 arranged in series with the pins 20. The lockable pin 22 is similar to the pins 20 in that it comprises a body 221 having a conical tip 223 at a first end and a planar bottom surface 225 at an opposite second end, the lockable pin 22 being configured such that when the conical tip 223 is engaged by the correct portion of a key, the planar bottom surface 225 is moved to the shear line S so that the external lock barrel 12 can be rotated. The body 221 of the lockable pin 22 comprises a waist section 227 where the diameter of the lockable pin 22 is locally reduced. As can be seen, in FIG. 2, the lockable pin 22 is located at the end 141 of the keyway 14, opposite the opening 143 of the keyway 14.

[0035] The lockable pin 22 has an unlocked configuration in which lockable pin 22 is movable when a key is inserted into the keyway 14 and a locked configuration in which the lockable pin 22 is prevented from being moved by a key when inserted into the keyway, as will be described in more detail below. The lockable pin 22 is held in the locked configuration by a pair of magnetic elements 24, 26 arranged either side of the keyway 14 which are configured to interact with a locking member in the form of a ball 28, as will now be described with reference to FIGS. 2 to 5.

[0036] A locking magnetic element 24 is fixed above the keyway 14 within the external lock barrel 12. A movable magnetic element 26 is mounted below the keyway 14 way, opposite the locking magnetic element 24 such that the locking magnetic element and movable magnetic element are aligned along a vertical axis (where used herein, the terms "vertical" and "horizontal" refer to orientations when the lock cylinder is in use, for example, when the lock cylinder is installed within a door). As can be best seen in FIGS. 3 and 4, the movable magnetic element 26 is movably mounted within a channel 30 which is oriented in a vertical direction such that the movable magnetic element 26 is movable within the channel 30 towards or away from the locking magnetic element 24 along a vertical direction. The locking magnetic element 24 and the movable magnetic element 26 each comprise respective opposing magnetic north and south poles, denoted herein and in the figures by "N" and "S". The locking magnetic element 24 and the movable magnetic element 26 are arranged with opposing poles closest to one another so that locking magnetic element 24 and the movable magnetic element 26 are attracted to one another. In particular, the magnetic south pole of the locking magnetic element 24S and the magnetic north pole of the movable magnetic element 26N are arranged to face one another so that the movable magnetic element 26 is held in a locked position at the upper end 301 of the channel 30 (i.e. the end closest to the locking magnetic element 24) by the magnetic attraction force between the upper and movable magnetic elements 24, 26. The movable magnetic element 26 is shown in the locked position in FIG. 2 and FIG. 3.

[0037] The ball 28 is located in a ball channel 32 which is oriented in a substantially horizontal direction. The ball channel 32 is positioned such that, when the lockable pin 22 is in the locked position, shown in FIG. 3, the waist section 227 of the lockable pin 22 is positioned in the ball channel 32 at a first end 321 of the ball channel 32. The ball channel 32 also intersects the movable magnetic element channel 30 such that part of the movable magnetic element 26 extends into the ball channel 32 when the movable magnetic element 26 is held in the locked position by the locking magnetic element 24. The size of the ball channel 32 is such that, when the movable magnetic element 26 is in the locked position, the movable magnetic element 26 holds the ball 28 in the waist section 227 of the lockable pin 22, as can be seen in FIG. 2 and FIG. 3. In this locked configuration of the lockable pin 22, any substantial vertical movement of the lockable pin 22 is prevented by shoulders 224 of the lockable pin 22 abutting with the ball 28, the shoulders 224 being provided either side of the waist section 227, in the region over which the diameter of the lockable pin 22 is reduced.

[0038] The lockable pin 22 is configurable to the unlocked configuration by inserting a key 35 comprising a magnetic key element 351, which is shown in isolation in FIG. 5, into the keyway 14. The key 35 comprises blade 353 having an elongate cross-section with a horizontal width W which is greater a vertical height H of the cross-section (the height direction H of the blade is indicated in FIG. 5). Note that the keyway 14, which is shaped to receive the key 35 has a correspondingly arranged elongate cross-section, with the horizontal width of the keyway being greater than the vertical height of the keyway 14.

[0039] A series of recesses 352 are formed on a lower surface 354 of the blade 353 (the lower surface 354 being oriented downwardly when the key 35 is inserted into the keyway 14). The recesses 352 are configured to receive the respective conical tips of the pins 20, 22 in order to move the ends of the pins to the shear line S, in a manner that will be well understood by the skilled person. The key 35 also comprises a magnetic key element 351 at the tip 355 of the blade 353 (the tip 355 of the blade 353 being the end of the blade 353 which is inserted into the keyway 14). The magnetic key element 351 is spaced apart from the recesses 352 in the width direction of the blade 353 and is oriented with its magnetic poles along the length direction L of the blade 353. In particular, the magnetic element 351 is positioned in the key 35 with its magnetic north pole 351N adjacent to a ramp 359 at the tip 355 of the blade 353 which is configured to engage with the conical tip 223 of the locking pin 22 in order to move the locking pin 22 into its corresponding recess 357 in the blade 353.

[0040] Configuration of the lockable pin 22 to the unlocked configuration shown in FIG. 5 by inserting the key 35 into the keyway 14 will now be described. When the key 35 is inserted into the keyway 14, the magnetic north pole 351N of the magnetic element 351 in the key 35 is moved between the locking magnetic element 24 and the movable magnetic element 26, which are positioned on either side of the keyway 14. The magnetic force of repulsion between the north pole 351N of the magnetic element 351 in the key 35 and the magnetic north pole 26N of the movable magnetic element 26 causes the movable magnetic element 26 to move from the locked position shown in FIG. 3 to the unlocked position shown in FIG. 4, where the movable magnetic element 26 is positioned at the lower end 303 of the channel 30. When the movable magnetic element 26 moves to the lower end 303 of the channel 30, the movable magnetic element 26 moves out of the ball channel 32, as shown in FIG. 4 and FIG. 5, such that the ball 28 is free to move along the ball channel 32, away from the lockable pin 22. The lockable pin 22 is therefore in an unlocked configuration in which it is no longer prevented by the ball 28 from being vertically depressed. Further movement of the key 35 into the keyway 14 causes the ramp 359 at the tip 355 of the key blade 353 to engage with and depress the lockable pin 22 as the ramp 359 moves over the lockable pin 22. The key 35 can therefore be moved to the position shown in FIG. 5 in which the conical tip 223 of the lockable pin 22 is received in its appropriate recess 357 of the key blade 353. In this position of the key 35, the ends of all of the pins 20, 22 are positioned at the shear line S and the external barrel 12 can be rotated.

[0041] When the key 35 is removed from the keyway 14, the magnetic force of attraction between the movable magnetic element 26 and the locking magnetic element 24 causes the movable magnetic element 24 to return to the locked position at the upper end 301 of the movable magnetic element channel 30, where the movable magnetic element 26 partially extends into the ball channel 32. As the movable magnetic element 26 moves back into the ball channel 32, the movable magnetic element 26 pushes the ball 28 along the ball channel 32 and into the position shown in FIG. 3 in which the ball 28 is positioned in the waist section 227 of the lockable pin 22. The lockable pin 22 therefore becomes configured to the locked configuration upon removal of the key 35 from the keyway 14.

[0042] If a key 37 without an appropriate magnetic element but cut with the same recesses as the key 35 is inserted into the keyway 14, as shown in FIG. 2, the movable magnetic element 26 remains in the locked position and the lockable pin 22 therefore remains in the locked configuration in which the key 37 cannot vertically displace the lockable pin 22. The key 37 without an appropriate magnetic element therefore cannot be used to operate the lock cylinder 10.

[0043] A cross-sectional view of an external barrel 12' of a lock cylinder 10' according to a second embodiment of the invention is shown in FIG. 7 and FIG. 8. The lock cylinder 10' is similar to the lock cylinder 10 of the first embodiment of the invention, and where the lock cylinder 10' of the second embodiment of the invention has features in common with the lock cylinder 10 of the first embodiment of the invention, those common features have been assigned the same reference numeral as used for the lock cylinder 10 of the first embodiment of the invention but with ' suffixed to the reference numeral. For example, the lock cylinder 10 of the first embodiment of the invention has a lockable pin 22 and the lock cylinder 10' of the second embodiment of the invention has a lockable pin 22'.

[0044] Like the lock cylinder 10 of the first embodiment of the invention, the lock cylinder 10' comprises a series of pins which are arranged along the keyway 14' of the external lock barrel 12' and are configured to be moved to a shear line S' by a key. However, for the purpose of clarity, only the lockable pin 22' is shown in FIGS. 7 and 8.

[0045] The lockable pin 22' comprises a first body portion 221' having a first diameter and a second body portion 222' which extends from the first body portion 221'. The second body portion 222' has a second diameter which is less than the first diameter. The second body portion 222' is joined to the first body portion 221' at a shoulder 224', where the diameter of the first body portion 221' reduces to the diameter of the second body portion 222'. The lockable pin 22' has a conical tip 223' at the end of the second body portion 222' and a planar bottom surface 225' at the end of the first body portion 221'.

[0046] The lockable pin 22' has a locked configuration, shown in FIG. 7 and FIG. 9, in which the lockable pin 22' is resiliently biased by a spring 39' into a locked position in which the second body portion 222' extends partially into the keyway 14' so that the conical tip 223' is spaced apart from the ceiling 145' of the keyway 14' and is prevented from being moved further into the keyway 14'. The lockable pin 22' has an unlocked configuration, shown in FIG. 8 and FIG. 10, in which the second body portion 222' is resiliently biased by the spring 39' into further into the keyway 14', such that the planar bottom surface 225' of the lockable pin 22' can be moved to the shear line S'. The lockable pin 22' is held in the locked configuration by a pair of magnetic elements 24', 26' arranged either side of the keyway 14' which are configured to interact with a locking member in the form of a ball 28', as will now be described.

[0047] A locking magnetic element 24' is fixed above the keyway 14' within the external lock barrel 12'. A corresponding movable magnetic element 26' is movably mounted within a channel 30' which is oriented in a vertical direction such that the movable magnetic element 26' is movable within the channel 30' towards or away from the locking magnetic element 24'. The movable magnetic element 26' comprises a wide body portion 261' having a first diameter and a narrow body portion 262' which extends from the wide body portion 261' and which has a second, smaller diameter. The movable magnetic element 26' is configured such that the magnetic south pole 26S' makes up the bulk of the wide body portion 261' and such that the magnetic north pole 26N' makes up the bulk of the narrow body portion 262'.

[0048] The locking magnetic element 24' and the movable magnetic element 26' are arranged with opposing poles closest to one another so that the magnetic elements 24', 26' are attracted to one another. In particular, the magnetic south pole of the locking magnetic element 24S' and the magnetic north pole of the movable magnetic element 26N' are arranged to face one another. The movable magnetic element 26' is therefore held in a locked position with its narrow body portion 262' at the upper end 301' of the channel 30' (i.e. the end closest to the locking magnetic element 24') by the magnetic attraction force between the locking magnetic element 24' and the movable magnetic element 26'. The movable magnetic element 26' is shown in the locked position in FIG. 7 and FIG. 9.

[0049] The ball 28' is located in a ball channel 32'. The ball channel 32' is configured such that, when the lockable pin 22' is in the locked configuration, the shoulder 224' of the lockable pin 22' is positioned in the ball channel 32' at a first end of the ball channel 32'. The ball channel 32' also intersects the movable magnetic element channel 30' such that the wide body portion 261' of the movable magnetic element 26' extends into the ball channel 32' when the movable magnetic element 26' is in the locked position. The size of the ball channel 32' is such that, when the movable magnetic element 26' is in the locked position, the wide body portion 261' of the movable magnetic element 26' holds the ball 28' against the shoulder 224' of the lockable pin 22', as can be best seen in FIG. 9. In this locked configuration of the lockable pin 22', the resilient basing force of the spring 39' biases the lockable pin 22' to a position in which the shoulder 224' of the lockable pin 22' abuts with the ball 28' so that the second body portion 222' of the lockable pin 22' is biased partially into the keyway 14' and is prevented from moving any further into the keyway 14' by the abutment of the shoulder 224' with the ball 28'.

[0050] The lockable pin 22' is configurable to the unlocked configuration when an appropriately cut key 35', 36' comprising an appropriately configured magnetic key element 351', 361' is inserted into the keyway 14'. A first key 35', which is shown in isolation in FIG. 11, comprises blade 353 having a series of recesses which are configured to receive the respective conical tips of the pins and lockable pin 22 in order to position the respective ends of the pins at the shear line S'. The magnetic element 351' is positioned adjacent the recess 357' along the length direction L' of the blade 353', the recess 357' being configured to receive the lockable pin 22'. The poles of the magnetic key element 351' are arranged along the length direction L' of the blade 353' such that the magnetic south pole 351S' is positioned closest to the tip 355' of the blade 353' and such that the magnetic north pole 351N' is positioned between the locking magnetic element 24' and the movable magnetic element 26' when the key 35' is fully inserted into the keyway 14', as shown in FIG. 8.

[0051] Configuration of the lockable pin 22' to the unlocked configuration by inserting the key 35' into the keyway 14' will now be described. When the key 35' is inserted into the keyway 14', the magnetic south pole 351S' of the magnetic element 351' in the key 35' moves between and past the locking magnetic element 24' and the movable magnetic element 26' before the key 35' becomes fully inserted into the keyway 14'. When the key 35' is fully inserted in the keyway 14', the north pole 351N' of the magnetic element 351' in the key 35' is positioned between the locking magnetic element 24' and the movable magnetic element 26'. The magnetic force of repulsion between the north pole 351N' of the magnetic element 351' in the key 35' and the magnetic north pole 26N' of the movable magnetic element 26' causes the movable magnetic element 26' to move from the locked position to an unlocked position in which the movable magnetic element 26' is positioned at the lower end 303' of the channel 30' i.e. the movable magnetic element 26' moves from the position shown in FIG. 7 to the locked position shown in FIG. 8.

[0052] When the movable magnetic element 26' moves to the unlocked position, the narrow body portion 262' of the movable magnetic element 26' moves into the ball channel 32' (as the wide body portion 261' moves out of the ball channel 32'), as can be best seen in FIG. 10. In this unlocked position of the movable magnetic element 26', the space along the ball channel 32' between the lockable pin 22' and the movable magnetic element 26' is increased. The ball 28' is no longer held in abutment with the lockable pin 22' and is free to move along the ball channel 32', away from the lockable pin 22'. However, the narrow body portion 262' extends into the ball channel 32' to prevent the ball 28' moving past the movable magnetic element 26'.

[0053] When the ball 28' is no longer held in abutment with the lockable pin 22', the resilient bias of the spring 39' pushes the lockable pin 22' into the keyway 14' towards the ceiling 145' of the keyway 14', where the lockable pin 22' engages with its corresponding recess 357' formed in the key 35' so that the planar bottom surface 225' of the lockable pin 22' is moved to the shear line S' and the external lock barrel 12' can be rotated, as shown in FIG. 8.

[0054] Note that an appropriately cut key which does not comprise an appropriately configured magnetic element can be fully inserted into the keyway 14' of the lock cylinder 10'. However, when this happens, the movable magnetic element 26' is not moved to the locked position, so lockable pin 22' remains in the locked configuration and the external barrel 14' cannot be rotated.

[0055] Configuration of the lockable pin 22' back to the locked configuration by removal of the key 35' from the keyway 14' will now be described. When the key 35' is removed from the keyway 14', the sloping surface 358' which partly forms the recess 357' in the key 35' that receives the lockable pin 22' moves over the lockable pin 22' and depresses the lockable pin 22' such that the shoulder 224' moves below the ball 28'. When the lockable pin 22' is in this depressed position, the magnetic south pole 351S' of the magnetic element 351' in the key 35' is moved between the locking magnetic element 24' and the movable magnetic element 26'. The magnetic force of attraction between the south pole 351S' of the magnetic key element 351' and the magnetic north pole 26N' of the movable magnetic element 26' causes the movable magnetic element 26' to return to its locked position at the upper end 301' of the channel 30'. As the wide body portion 261' of the movable magnetic element 26' moves back into the ball channel 32', the ball 28' is pushed back into abutment with the shoulder 224' of the lockable pin 22' so that the lockable pin 22' becomes configured to the locked configuration. The movable magnetic element 26' then remains held in the locked position by the locking magnetic element 24' upon removal of the key 35' from the keyway 14'

[0056] A second key 36' which is suitable for operating the lock cylinder 10' of the second embodiment of the invention is shown in FIG. 12. The second key 36' comprises a series of recesses which are substantially identical to the recesses provided in the first key 35', and are thereby configured to receive the respective conical tips of the pins and lockable pin 22' in order to position the respective ends of the pins at the shear line S'. However, in this second key 36' the polarity of the magnetic element 361' has been reversed with respect to the first key 35' so that the magnetic north pole 351N' is positioned closest to the tip 365' of the blade 363'. Because the polarity of the magnetic element 361' has been reversed, the magnetic element 361' has been moved along the blade 363' away from the tip 365', relative to the key 35', so that the magnetic north pole 361N' of the magnetic key element 36' is positioned between the locking magnetic element 24' and the movable magnetic element 26' when the key 36' is fully inserted into the keyway 14' (as is the case when the key 35' is fully inserted into the keyway).

[0057] The key 36' functions in substantially the same way as the key 35' in moving the movable magnetic element 26' to the unlocked position. In particular, when the key 36' is fully inserted into the keyway 14', as shown in FIG. 13, the magnetic north pole 361N' is positioned between the locking magnetic element 24' and the movable magnetic element 26', which causes the movable magnetic element 26' to move to the unlocked position. However, when the key 36' is removed from the keyway 14', the magnetic key element 361' does not return the movable magnetic element 26' to the locked position, instead it is the magnetic force of attraction between the south pole 24S' of the locking magnetic element 24' and the magnetic north pole 26N' of the movable magnetic element 26' that causes the movable magnetic element 26' to return to the locked position.

[0058] A cross-sectional view of an external barrel 12" of a lock cylinder 10" according to a third embodiment of the invention is shown in FIG. 14 and FIG. 15. The lock cylinder 10" is similar to the lock cylinder 10' of the second embodiment of the invention, and where the lock cylinder 10" of the third embodiment of the invention has features in common with the lock cylinder 10' of the second embodiment of the invention, those common features have been assigned the same reference numerals used for the lock cylinder 10' of the second embodiment of the invention but with " suffixed to the reference numeral. For example, the lock cylinder 10' of the second embodiment of the invention has a lockable pin 22' and the lock cylinder 10' of the second embodiment of the invention has a lockable pin 22".

[0059] The main point of difference between the lock cylinder 10" of the third embodiment of the invention and the lock cylinder 10' of the second embodiment of the invention is that that the lock cylinder 10" of the third embodiment is provided with a locking magnetic element 24" comprising a first locking sub-element 24A" and a second locking sub-element 24B" and a movable magnetic element 26" comprising a first movable sub-element 24A" and a second moveable sub-element 24B". The configuration, position, and polarisation of the first locking sub-element 24A" is substantially identical to the locking magnetic element 24' of the lock cylinder 10' of the second embodiment of the invention. The configuration, position, and polarisation of the first movable sub-element 26A" is substantially identical to the movable magnetic element 24' of the lock cylinder 10' of the second embodiment of the invention.

[0060] The second locking sub-element 24B" is positioned adjacent to the first locking sub-element 24A" along the longitudinal axis X" of the external barrel 14", and is positioned closer to the entrance 143" to the keyway 14" than the first locking magnetic element 24A". Similarly, the second movable sub-element 26B" is positioned adjacent to the first movable sub-element 26A" along the longitudinal axis X" of the external barrel 14", and is positioned closer to the entrance 143" to the keyway 14" than the first movable sub-element 24A", the second movable sub-element 26B" being located at the same position along the longitudinal axis X" of the barrel 14" as the second locking sub-element 24B" but is positioned on the opposite side of the keyway 14". The second movable sub-element 26B" is coupled to the first movable sub-element 26A", such that the movable sub-elements 26A", 26B" are configured to move together. The movable sub-elements 26A", 26B" may be coupled using an adhesive, for example.

[0061] The polarities of the second locking sub-element 24B" and the second movable sub-element 26B" are reversed with respect to the polarities of the respective first locking sub-element 24A" and first movable sub-element 26A". In particular, the second sub-elements 24B", 26B" are oriented such the magnetic north pole of the second locking sub-element 24BN" faces the magnetic south pole 26BS" of the second movable sub-element 26B".

[0062] The lock cylinder 10" of the third embodiment of the invention functions in substantially the same way as described above with respect to the lock cylinder 10' of the second embodiment of the invention. In particular, insertion of key, for example, the key 35' or the key 36', causes the movable magnetic element 26" to be moved from the locked position to the unlocked position so that the lockable pin 22" can be moved to the shear line S". For example, FIG. 15 shows the key 36' is fully inserted into the keyway 14" so that the magnetic north pole 361N' of the magnetic key element 361' is positioned between the first locking sub-element 24A" and the first movable sub-element 26A", which causes the movable magnetic element 26" to move to the unlocked position shown in FIG. 15 due to the magnetic repulsive force between the magnetic north pole 361N' of the magnetic key element 361' and the magnetic north pole 26AN" of the first movable sub-element 26A". However, because the locking magnetic element 24" and the movable magnetic element 26" are now both formed by two magnetic sub-elements 24A", 24B", 26A", 26B", the magnetic force of attraction between the locking magnetic element 24" and the movable magnetic element 26" is stronger, when compared to the magnetic elements 24', 26' of the lock cylinder 10'. As such, when the key 36' is removed from the keyway 14", the stronger magnetic force of attraction between the magnetic elements 24", 26" may cause the movable magnetic element 26" of the third embodiment of the invention to return to the locked position more reliably than the movable magnetic element 26' of the second embodiment of the invention.

[0063] In a fourth embodiment of the invention which is similar to the lock cylinder 10" of the third embodiment of the invention, a blocking member 50'" may be provided in the keyway 14'" in order to improve the resistance of the lock cylinder to picking attacks, as shown in FIG. 16. The blocking member 50'" is resiliently biased by a spring 51'" into the keyway 14‴, and into engagement with the conical tip 223'" of the lockable pin 22'". The blocking member 50'" comprises a sloping cam surface 53'" which faces towards the entrance of the keyway 14'". The blocking member 50'" is configured to be lifted away from the lockable pin 22'" when a corresponding cam surface of an appropriate key engages with the sloping cam surface 53'" as the key is inserted into the lock cylinder. The blocking member 50'" therefore restricts access to the pins positioned behind the blocking member and may mitigate susceptibility to picking attacks. It will be appreciated that the blocking member 50'" could also be used with the lock cylinder 10' of the second embodiment of the invention.

[0064] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.

[0065] In the embodiments of the invention described above, the various magnetic elements are oriented with their respective polarities in certain directions. It will be appreciated that it is within the scope of the invention for those polarities to be reversed. For example, in an embodiment similar to the lock cylinder 10' according to the second embodiment of the invention, the magnetic north pole of the locking magnetic element and the magnetic south pole of the movable magnetic element are arranged to face one another. In this embodiment, the movable magnetic element is configured such that the magnetic north pole makes up the bulk of the wide body portion and such that the magnetic south pole makes up the bulk of the narrow body portion.

[0066] The lock cylinders of the second and third embodiments of the invention each comprise a plurality of pins with only one of those pins being a lockable pin. It is within the scope of the present invention for any of the pins of a lock cylinder to be a lockable pin. In other embodiments of the invention, two or more of the pins are lockable pins which are configured in a manner as described above in relation to any of the first, second, and / or third embodiments of the invention. For example, in a further embodiment of the invention a lock cylinder comprises a first lockable pin as described in relation to the first embodiment of the invention, a second lockable pin as described in relation to the second embodiment of the invention, and a third lockable pin as described in relation to the third embodiment of the invention. In embodiments comprising more than one lockable pin, the lock cylinder will be operable by a key comprising a plurality of magnetic key elements. For example, a key 38 which is suitable for operating a lock cylinder comprising three lockable pins is shown in FIG. 17. As can be seen, the key 38 comprises three magnetic key elements 381 distributed along a length direction L of the blade 383, the magnetic key elements 381 being spaced apart from the recesses 382 configured to engage with the pins in a width direction W of the blade 383.

[0067] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

1. A lock cylinder (10, 10', 10") comprising: a housing (11, 11', 11"), a barrel (12, 12', 12") rotatably mounted within the housing (11, 11', 11 "), a pin (22, 22', 22") movably mounted within the barrel (12, 12', 12"), a locking member (28', 28', 28") for controlling the position of the pin (22, 22', 22") within the barrel (12, 12', 12"), and a movable magnetic element (26, 26', 26") for controlling the position of the locking member (28', 28', 28") with respect to the pin (22, 22', 22"), wherein: the barrel (12, 12', 12") comprises a keyway (14, 14', 14") configured to receive a key comprising a magnetic key element and the pin (22, 22', 22") is configured to be moved by the key to a shear line (S, S', S") to enable the barrel (12, 12', 12") to be rotated with respect to the housing (11, 11', 11"); the movable magnetic element (26, 26', 26") has a locked position in which the movable magnetic element (26, 26', 26") holds the locking member (28', 28', 28") in a position in which the locking member (28', 28', 28") prevents the pin (22, 22', 22") being moved to the shear line (S, S', S"); the movable magnetic element (26, 26', 26") has an unlocked position in which the pin (22, 22', 22") is movable to the shear line (S, S', S"); and the movable magnetic element (26, 26', 26") is configured to be moved from the locked position to the unlocked position by the magnetic key element when the key is inserted into the keyway (14, 14', 14").

2. A lock cylinder according to claim 1, wherein the lock cylinder comprises a locking magnetic element, wherein the movable magnetic element is positioned on a first side of the keyway; the locking magnetic element is positioned on an opposite second side of the keyway; and the movable magnetic element is held in the locked position by the magnetic attraction of the movable magnetic element to the locking magnetic element.

3. A lock cylinder according to claim 2, wherein the movable magnetic element is configured to be moved from the unlocked position to the locked position by the magnetic attraction of the movable magnetic element to the locking magnetic element.

4. A lock cylinder according to any preceding claim, wherein the barrel comprises a channel along which the locking member is movable; the pin is located at a first end of the channel; and, when the movable magnetic element is in the locked position, the movable magnetic element at least partially extends into an opposite second end of the channel to hold the locking member in the position in which the locking member prevents the pin being moved to the shear line.

5. A lock cylinder according to claim 4, wherein the movable magnetic element comprises a first portion having a first width and a second portion having a second width which is less than the first width; in the locked position of the movable magnetic element at least part of the first portion extends into the channel; in the unlocked position of the movable magnetic element, at least part of the second portion extends into the channel, the width of the second portion being such that the locking member does not restrict movement of the pin when the magnetic element is in the unlocked position.

6. A lock cylinder according to any preceding claim, wherein the pin comprises a shoulder and, when the movable magnetic element is in the locked position, the movable magnetic element holds the locking member in a position in which the locking member abuts with the shoulder of the pin to prevent the pin being moved to the shear line.

7. A lock cylinder according to any preceding claim, wherein, when the movable magnetic element is in the locked position, the locking member holds the pin in a position in which the pin is spaced apart from a ceiling of the keyway.

8. A lock cylinder according to claim 7, wherein the pin is resiliently biased towards the ceiling of the keyway and, when the movable magnetic element is in the locked position, the pin can be moved against the resilient bias away from the ceiling of the keyway.

9. A lock cylinder according to any preceding claim, wherein the barrel defines an axis and, when the movable magnetic element is in the unlocked position, the locking member is configured to move away from the pin in a direction perpendicular to the axis of the barrel.

10. A locking cylinder according to any preceding claim, wherein the pin is configured to be moved along an axis to the shear line and the movable magnetic element is movable between the locked position and the unlocked position in a direction parallel with the axis of movement of the pin.

11. A locking cylinder according to any preceding claim wherein the movable magnetic element is contained within a channel; when the movable magnetic element is in the locked configuration the movable magnetic element abuts a wall defining a first end of the channel; and when the movable magnetic element is in the unlocked configuration; the movable magnetic element abuts a wall defining an opposite second end of the channel.

12. A lock cylinder according to any preceding claim, wherein the locking member is a ball.

13. A lock cylinder according to any preceding claim, wherein the keyway has an elongate cross-section having a horizontal width which is greater than a vertical height of the cross-section; the pin is located at a first position along the width of the keyway; the movable magnetic element is located below the keyway at a second position along the width of the keyway such that the pin and the movable magnetic element are spaced apart along the width of the keyway.

14. A key (35, 35', 36') for the lock cylinder of any preceding claim, wherein the key (35, 35', 36) comprises a blade (353, 353', 363') comprising a recess (357, 357', 367') and a magnetic key element (351, 351', 361'); the recess (357, 357', 367') is configured to receive the pin of the lock cylinder; and the magnetic key element (351, 351', 361') is configured such that, when the key (35, 35', 36') is inserted into the keyway of the lock cylinder, the magnetic key element (351, 351', 361') moves over the movable magnetic element and causes the movable magnetic element to move to the unlocked position.

15. A kit of parts comprising a lock cylinder according to any of claims 1 to 13 and a key comprising a magnetic key element, the key being configured such that the barrel of the lock cylinder can be rotated with respect to the housing when the key is inserted into the keyway.

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