WO2024105419A1

WO2024105419A1 - Lock assembly

Info

Publication number: WO2024105419A1
Application number: PCT/GB2023/053034
Authority: WO
Inventors: Yizhou SHEN
Original assignee: Shen Yizhou
Priority date: 2022-11-18
Filing date: 2023-11-20
Publication date: 2024-05-23
Also published as: GB2624453A; GB202217331D0

Abstract

Lock assembly having, a house member, a plug located at least partially in the house member and rotatable with respect thereto, having, an outer surface, at least one security channel being open at the outer surface, at least one security pin located in the security channel and configured to be movable with respect thereto, a lock mechanism selectively operable to move the lock assembly between a locked and unlocked condition, a trap mechanism configured to render the lock assembly inoperable by restricting the rotation of the plug by engaging with the security pin when the security pin moves a specified distance from the plug's outer surface.

Description

Lock assembly The present disclosure comprises a lock assembly, specifically key locks that require a key to be inserted into a keyway to lock or unlock the assembly. Introduction Lock assemblies are used to inhibit access to a particular area with some requiring the user to have a key that allows the assembly to be unlocked. The pin tumbler lock is one of the most common locks used on the market. The locks generally comprise a plurality of pin tumblers that when moved into the correct alignment, will allow a plug to rotate within a housing. This lock is vulnerable to several methods of attack that allow unauthorised people to open the lock without the correct key. ‘Bumping’ is where an incorrect or bump key is placed into the keyway and then forcibly struck with an object, transferring energy to the pin tumblers and causing them to jump. By twisting the incorrect key while the pin tumblers are floating freely above the plug, it is possible to open the lock. The locks can also be picked using tools to manually move the pins to the correct alignment without using any key. US2011214462 discloses a lock that uses springs to bias the pin tumblers towards the plug, making the lock more difficult to bump. However, such locks can still be bumped, providing the pins do not return to their position before the plug is rotated. US5964111 is an example of a lock with additional ‘security’ tumbler pins that make the lock more difficult to pick. However, experienced pickers can distinguish between the actual and security pins making the lock less effective. Furthermore, these locks are still susceptible to other forms of attack, such as impressioning or decoding. While some locks have been configured to resist specific types of attack, professional pickers will be able to attempt multiple methods to break the lock. Conventional locks will allow for successive attacks to be performed. Furthermore, the locks of the prior art allow for successive modes of attack meaning, that lock pickers will eventually open a lock either via repetition of a specific attack or trying alternative methods. The present invention aims to mitigate one or more of the above problems. Summary of invention According to one aspect of the invention there is a lock assembly having a house member, a plug located at least partially in the house member and rotatable with respect thereto; a lock mechanism selectively operable to move the lock assembly between a locked and unlocked condition; a security mechanism movable between an operatable and inoperable condition; a trap mechanism; wherein the trap mechanism is configured to provide a force path to the security mechanism in the inoperable condition to restrict rotation of the plug. According to another aspect of the invention there is a lock assembly having, a body member, a plug located at least partially in the body member and rotatable with respect thereto, the plug comprising a security channel and a corresponding lock channel extending in a substantially perpendicular direction to the security channel, a security pin located and movable within the security channel, and a lock pin located and movable within the lock channel, the lock pin being biased to engage to the security pin and configured to selectively lock the position of the security pin in the security channel, a trap mechanism configured to allow or restrict rotation of the plug depending upon the position of the security pin being in a correct or incorrect position in the security channel. Optionally, the trap mechanism does not provide a force path to the security mechanism in the operable condition such as not to restrict rotation of the plug. The trap mechanism may prevent rotation of the plug. The trap mechanism may prevent and/or restrict rotation of the plug in a first direction and/or second direction. The security mechanism may comprise at least one security pin, where the security pin is located in a security channel of the plug. The security mechanism may comprise a lock pin to selectively lock the position of the security pin in the security channel. According to another aspect of the invention there is a lock assembly having, a house member, a plug located at least partially in the house member and rotatable with respect thereto, having, an outer surface, at least one security channel being open at the outer surface, at least one security pin located in the security channel and configured to be movable with respect thereto, a lock mechanism selectively operable to move the lock assembly between a locked and unlocked condition, a trap mechanism configured to render the lock assembly inoperable by restricting the rotation of the plug by engaging with the security pin when the security pin moves a specified distance from the plug’s outer surface. The security channels and security pins define a security mechanism. A force path may be formed between the house member and plug to prevent or restrict rotation of the plug. More preferably, the force path may act through the security pin and trap mechanism. The plug may have a body portion that extends in a longitudinal axis. The body portion may be cylindrical and have an outer surface. The plug may have a keyway. The outer surface may comprise a fixing plate located over at least a portion of the one or more security channels. The fixing plate keeps the security pins (at least partially) inside the plug. The fixing plate has apertures for allowing a protrusion member of the security pin to extend through. The lock assembly only requires a single security channel (and therefore a single security pin) to prevent/restrict rotation of the plug; however, there may be a plurality of security channels; for example, two or more security channels; more preferably there are at least five security channels. The security channels are preferably aligned in the longitudinal axis. The security channels are open at one end to the outer surface, and may be open at the keyway. The security channels preferably extend in a radial direction from the longitudinal axis. The security channel may have a diameter of at least 1mm, or at least 2mm or at least 5mm, or at least 10mm. The security channel may be substantially cylindrical, square or any other polygonal. The plug and/or security mechanism may comprise one or more lock (or lock pin) channels, preferably there are an equal amount of lock and security channels. The lock channels preferably extend in a direction that is perpendicular to the security channel. The lock channel may be open at the outer surface, and also the security channel; preferably the mid-point of the security channel. The lock channel may be offset with respect to the longitudinal axis; that is to say it may extend in a direction that is parallel to a radial direction extending from the longitudinal axis. The plug may further comprise channels configured to locate pins of the lock mechanism, which may be a pin tumbler mechanism. The channels of the lock mechanism and the security channels may be angled to one another. Preferably they are angled 90 degrees such as to be perpendicular. In other embodiments however they may be any practical angle (for example, at least 20 degrees, at least 45 degrees, at least 60 degrees, at least 90 degrees, at least 120 degrees, or at least 180 degrees). In some embodiments the security channels and channels of the lock mechanism may extend in directions that are parallel. The plug may comprise a first recess for locating an obfuscation or vibration mechanism (herein referred to as a flexi-fake mechanism), where the flexi-fake mechanism has one or more obfuscation or vibration pins (herein referred to as flexi-fake pins). The recess may be arched shaped. Preferably there is a second recess for locating a second flexi-fake mechanism. The recess may form a quadrant of a circle. The flexi-fake mechanism may be pivotably mounted in the recess. The first trap may have at least one flexi-fake pin pivotally mounted to the plug and configured to engage with a gate upon rotation. The plug may further comprise a pawl body having a pawl to actuate a mechanism, such as door lock. The pawl body rotates in unison with the body portion. The house member may have a substantially tubular body for locating the plug in. The house member may be radially bigger than the plug such that there is a gap when the plug is inside the house member. The gap may be substantially annulus shaped. The inner surface of the house member may have formations that extend into the tubular body. The formations may engage with the plug such as to maintain its position. The formations may comprise one or more first formations that extend circumferentially around the inner surface. There may be a plurality of first formations. There may be one or more second formations that extend in a direction parallel to the longitudinal axis. The second formations may be located proximal to the apertures in the house member that are configured to receive pins (for example of the lock mechanism or lock pins described below). The second formations may act to obscure the pins as they protrude through the gap, such that they cannot be accessed by lock pickers. The second formations may act as guides to ensure the correct alignment of the pins that extend through. The house member may have first and second ends, where one or both ends may be open. The second end may comprise a lip that at least partially extends around the periphery. Preferably, the lip may extend around the whole of the periphery. The lip may comprise a protrusion, where the protrusion is configured to engage with the body member. The security pins may comprise first and second members. The security pin (e.g., the first member) may comprise an engagement member, where the engagement member may be a plurality of ridges. The ridges may be symmetrical or asymmetrical and may extend partially or fully around the security pin. The security pin (e.g. the first member) may have an abutment that is configured to engage with the step of the plug such as to prevent the security pin from falling through the channel. The first and second members may be separable, such that if someone were to attempt to “bump” the lock, they may temporarily disengage, increasing the difficulty of picking the lock. The second member may have a protrusion configured to extend into or out of the security channel in operation. Where there are a plurality of security channels and security pins, the protrusion of each pin may be unique; for example, different sizes, lengths, widths, diameters or shapes. The length of the protrusion may be at least 1mm, or at least 3mm, or at least 5mm, or at least 10mm or at least 20 mm. The protrusions may be cylindrical, domed, triangular, or any other polygonal. The diameter of the protrusion may be substantially equal to the diameter of the security channel. Alternatively, the protrusion may be smaller such that there is a gap between the protrusion and security channel. The lock assembly (e.g., the security mechanism) may comprise one or more lock pins configured to fix the position of the security pin (e.g., the protrusion) with respect to the plug (e.g., in the security channel). Preferably, there are an equal number of lock pins to security pins. The lock pins may have an engagement member that corresponds to the engagement member of the security pin (e.g., the ridges thereof). The engagement member may have a needle. The lock pins may be locatable in the lock channels and/or may be axially movable in the lock channels. The corresponding engagement members of the lock and security pins may take other forms; specifically, any mechanism that permits selective movement of the security pin with respect to the lock pins. For example, magnetics, pawl and ratchets, gearing etc. The lock pin may be comprised of first and second parts. The first part may be locatable in the lock channel, and may have a surface that is shaped to correspond with the outer surface of the plug. Preferably, the surface is shaped to be flush with the outer surface. It is preferable that the surface does not protrude from the plug such that it does not inhibit the rotation of the plug. However, as the security pin moves in the security channel the surface will protrude as the needle rides over the ridges. The second part of the lock pin is separable from the first pin to permit rotation. The second part may be located in a channel of the house member. The second part is biased in a direction towards engagement of the first part (i.e. the surface thereof). The first part may have a surface that is flush with the outer surface of the plug. In some embodiments, the lock pin may be a unitary part. A pin shield may locate around part of the lock pin such as to maintain the lock pin inside the plug and prevent lock pickers from using tools to insert through the security channel. This prevents lock pickers gaining information about the lock pins (e.g. the length and/or shape of the protrusion). The pin shield may have a tubular body, and a lip at one end. The lip may be the same size as the diameter of the security channel. The trap mechanism may comprise a first trap, which may be configured to engage with the security mechanism (e.g., the security pins, preferably the protrusions thereof) upon rotation of the plug. The first trap may be pivotally mounted to the inner surface of the house member. The first trap may form part of a force path between the house member and plug to prevent or restrict rotation. The first trap may permit rotation in a first direction (e.g. a clockwise direction) such that there is no force path between the plug and house member, but restrict or stop rotation in the opposite direction (e.g., anti- clockwise) via the force path. The first trap may have a gate, where the gate permits selective rotation, for example in a first direction but not the other direction. The gate may comprise one or more pawls that extend towards the plug, for engagement with the security pins (e.g, the protrusions thereof). The gate may comprise a plurality of pawls, each pawl being configured to engage with a security pin (e.g., the protrusions). The pawls may be identical to one another or have unique shape or features. The gates may be elongate and extend in a direction along the longitudinal axis. The first trap may comprise a second gate, where the first and second gates permit rotation in opposite directions to one another. The trap mechanism may have a first trap configured to engage with the security pin when the security pin protrudes beyond the outer surface. The first trap may have at least one gate configured to permit rotation of the plug in a first direction and restrict or inhibit rotation in the opposite second direction. The first trap may have first and second gates, wherein the first gate is configured to permit rotation of the plug in a first direction and restrict or inhibit rotation in the opposite second direction, the second gate configured to permit rotation in the second direction and restrict or inhibit rotation in the first direction, wherein at least one gate may be pivotally mounted to the house member. In operation, the lock assembly may have a first condition whereby the security pins are movable in the security channel. The first condition may correspond to a specific orientation of the plug in the house member or body. The orientation may be defined where the lock pin channels of the plug and formations (e.g. second formation) of the house member are in radial alignment, or when the security pins are axially moveable in the security channel. Thus in the first condition, the first and second parts of the lock pin may be engageable. The first condition or orientation may correspond to a starting condition where a key is selectively insertable into the keyway. There may be correct and incorrect positions for the security pin in the security channel. The lock assembly may have a second condition, being defined when the lock assembly is located from the first condition. In the second condition, the first and second parts are not directly engaged, and so the first part is positionally fixed within the plug. This means the security pin can’t move within the security channel. There may be one or more actuated orientations in the second condition where the trap mechanism is actuated to restrict the rotation of the plug when the security pin is in the incorrect position. The lock pin may be arranged to permit the security pin to move between the correct and incorrect positions in the security channel in the first condition and lock the position of the security pin in the second condition. The lock pin may have an engagement member for engaging with a corresponding engagement member on the security pin. The engagement member of the lock pin may have a needle or pointed edge, the corresponding engagement member on the security pin having a plurality of ridges, where one ridge may correspond to the correct position, and at least one ridge corresponds to the incorrect position. The first or second gates may have a length that is substantially equal to the gap between the inner surface of the house member and the outer surface of the plug. The first and second gates may be positioned adjacent the first condition/orientation such as to define a zone wherein the plug can rotate without engagement with either the first or second gates. The zone may be less than 180 degrees, may be less than 90 degrees, may be less than 45 degrees, may be less than 30 degrees, may be less than 20 degrees. In some embodiments, the gate comprises a body element that is configured to allow rotation in a first direction but inhibit rotation in a second direction. The body element has a substantially semi-cylindrical body portion and a flat portion; where the gate is rotated in the allowed direction, the flat portion of the body portion faces the plug and does not prevent rotation. Where the gate is rotated in the incorrect direction (e.g. under a brute force attack from a lock picker), the body portion rotates bringing the curved surface of the cylinder portion into contact with the plug. The metal-on-metal contact between the body element and plug prevents rotation of the plug. The gate may be pivotably mounted to the body element. The house member, plug and or body may comprise a track for locating the body element. The lock mechanism may comprise a second trap configured to restrict or prevent rotation of the plug in the house member. The second trap may comprise one or more trap pins, movable in each of the trap pin channels. The trap pins may be biased into engagement with the plug (e.g., the outer surface thereof). In some embodiments the lock assembly may only have the second trap mechanism or a variation of the second trap and not the first trap. The trap pins may be configured to only be moveable in a direction towards the plug. The trap pin may comprise a plurality of teeth, which may be asymmetrical. The teeth may be engageable with a pawl fixed to the lock assembly, for example, on the body or house member. The engagement between the pawl and teeth may permit movement of the trap pin with respect to the body and/or house member. The second trap may form a force path between the body and/or house member, through to the plug to restrict and/or prevent rotation of the plug. The force path may act through the trap pin when engageable with the security pin and/or security channel. The bias acting on the security pin, and/or lock pin, and/or trap pins may be provided through springs. In operation, the key is insertable into the keyway when in the first condition. The security pin may move upon engagement with key, specifically a first profile thereof, such as to overcome or move against the bias force acting on the security pin. As the security pin moves, the engagement member of the lock pin (e.g., the needle thereof) rides over the ridges. The position by which the pins move is dependent upon the first profile of the key. The ‘correct’ first profile may move the security pin (e.g., the protrusion thereof), such that it is flush with the outer surface. Where the lock assembly is being picked or an incorrect key is inserted, the security pin will move into a condition whereby the force path may act on the plug to prevent rotation. The force path may exist when the security pin (e.g., the protrusion) either extends above or below the outer surface of the plug by a preselected distance. The distance may be at least 1mm, at least 2mm, at least 5 mm, or at least 10mm. The protrusion may extend the full distance between the gap of the house member and plug. Where the incorrect key is inserted, the security pin may appear to form a recess in the plug (i.e., the security channels forming the walls and security pin forming the bottom of the recess). The second trap (e.g., the trap pin) is configured to provide a force path between the plug and either the body or house member, when the security pin forms a recess. The trap pin may therefore engage with the recess of the plug on rotation. Once the second trap enters the recess, the force path is formed between the plug and either house member or body which prevents rotation of the plug. The trap mechanism may not be resettable once the force path between the house member and plug has engaged. The activation of the force path may indicate that a lock picker is attempting to break the lock assembly. The force path may prevent the plug from rotating back to the first condition. Thus, once the force path is engaged, the lock assembly may be permanently inoperable such as to prevent further attacks. It should be understood that the lock assembly only requires one of the first or second traps to provide a force path between the house member or body member and the plug. In some embodiments there may only be the first trap, in other embodiments there may only be the second trap. The trap mechanism may comprise a second trap configured to engage with a recess of the plug formed by the security channel and security pin when the security pin moves into the plug by a preselected distance from the outer surface. The trap may have at least one trap-pin lock configured to allow the at least one trap pin to move in a direction towards the plug, and prevent the trap pin moving in an opposite direction, e.g. such as to prevent disengagement of the second trap and recess once engaged. According to another aspect of the invention there is a key suitable for use with a lock assembly, having a first profile for engagement with the security pin and a second profile for engagement with the lock mechanism. The first and second profiles may be perpendicular to one another. In some embodiments, the security channel is not open (e.g. being at least partially closed or obscured), and may be closed with a plate being flush to the outer surface of the plug. The security pin may still move within the security channel, but may not protrude from the plug, eg the security pin may not directly engage with any part of the housing. A biasing force or member may bias the security pin into engagement with a key. A spring may be located may positioned between the security pin and plate. The security pin may be a unitary part. The movement of the security pin in the security channel may be perpendicular to the movement of the lock pins. Hence the security channels may be perpendicular to the lock pin channel. The security pin may be rotationally fixed with respect to the security channel such that it can’t rotate with respect thereto. The security pin may comprise at least one guide member to locate into a corresponding shaped guide in the security channel to prevent rotation. The security pin may comprise an open recess, which may extend substantially along the length of the pin. The recess is located on the opposite side of the security pin to the ridges, i.e. at least a portion of the ridges is 180 degrees from at least part of the recess. The lock pin may engage with the ridges 180 degrees from the recess. A second engagement member may be in the recess, which forms a protrusion. The second engagement member divides the recess into two pits capable of receiving/locating an engagement member of the lock mechanism, (i.e. a check pin needle). The protrusion may comprise an engagement surface being flush with the outer surface of the security pin such that the radius of the of the pin is constant (i.e. substantially cylindrical) at the region of the protrusion. The protrusion may be comprised from two or more flat surfaces, arranged to form an apex/edge. The second engagement member may extend from the base of the recess, or in a direction that is perpendicular from the base of the recess. There security pin may comprise a plurality of first and/or second engagement members. The security pin extends along a longitudinal axis and may be substantially cylindrically shaped such as to be elongate in the longitudinal axis. Each of the first and second engagement members (i.e. the plurality of ridges and/or protrusions) may be spaced along the longitudinal direction. For example, each ridge is spaced apart from an adjacent ridge. Each of the first and second engagement members may extend radially from the longitudinal axis (i.e. perpendicularly from the axis). The radial direction may define a plane for each engagement member. Each engagement member curved in their own respective planes, the second engagement member may be in the same plane as one of the first engagement members i.e. one of the ridges, or in a plane that is parallel to one of the first engagement members. The lock assembly may comprise a check pin, which in turn may comprise a check pin body and an engagement member. The check pin body may be hyperboloidal shaped, such that the radius of the body varies along its length. The engagement member may be a needle, configured for engagement with the second engagement member of the security pin and also capable of locating into the pits/recesses either side of the second engagement mechanism. The engagement member (e.g. the needle) may be the same length as the depth of the open recess as measured from the outer surface of the security pin. Optionally the engagement member may be smaller in length as the depth of the open recess. The plug may comprise a check pin channel for locating the check pin. The check pin may be substantially movable within the check pin channel. The check pin channel may be parallel to the lock pin channel and may be in axial alignment. The lock pin may be capable of moving in axial alignment with the check pin. Hence the check pin channel may be perpendicular to the security pin channel and the check pins may be capable of moving in a direction which is perpendicular to the direction of movement of the security pins. The check pin channel may be configured to receive a portion of the trap mechanism, i.e. the trap pin thereof (eg of the second trap). For example, the diameter of the check pin channel may be greater than the diameter than the trap pin of the trap mechanism. In this embodiment, the trap pin doesn’t move into the security channel, but rather the check pin channel. The security channel may be closed by a closing plate. The check pin may have engagement member for engaging with the trap mechanism, specifically, the trap pin thereof. The key channel may be perpendicular to the any/all of the lock pin, check pin, trap pin, security pin channels. The lock assembly may comprise an engagement pin which in turn is comprised of first and second parts. When the first and second parts are in axial alignment, they form a substantially cylindrical body, where one part may have an engagement surface for engaging with the check pin body. The first and second parts may have surfaces which correspond to the curve of the plug or house member or body. The first part may be locatable within the plug and is held in position by the house member or body. The second part may be in a channel is house member or body. The lock assembly may have first condition/orientation wherein the key is insertable and withdrawable from the lock assembly. In this position the lock pin is movable in the lock pin channel. The security pins axially move within in the security channel to correspond with the key bitting. As the key security pins move, the lock pin rides over the ridges. The key bitting therefore determines the position of the second engagement member (of the security pin) within the security channel. The check pin and engagement pins are fixed in position by engagement with the plug and/or housing or body, eg. There may be a force path that is transmitted between the housing and/or plug to the first part of the engagement pin to the check pin. Once rotated from the first condition, the key may no longer be withdrawable from the lock assembly. The lock pin fixes the position of the security pin. An actuated orientation may be defined when the plug is orientated with respect to the body in a position whereby the trap mechanism is actuated to prevent, restrict, or inhibit rotation of the plug with respect to the body or house member. For example, it may be defined where the trap pins are in axial alignment with check pins, and the check pin may be axially movable within the lock pin in this orientation. The actuated orientation may correspond to the orientation whereby the first and/or second traps prevent rotation back to the first condition, for example where the protruding security pin is prevented to rotate by the first/second gates, or where the trap pins are capable of entering the security channels. If the second engagement member is in the incorrect position, then the trap mechanism will define a new force path with the plug to prevent further rotation, rendering the lock permanently unusable. Specifically, if the second engagement member is in the incorrect position, the trap pin will move into the check pin channel which prevents further rotation of the plug. The trap pin can only move axially in one direction, and may be irreversibly moved in one direction, meaning once it enters the plug it cannot be withdrawn. In the actuated orientation, the check pin is axially moveable in the check pin channel. Hence if the second engagement member is in the incorrect position, the check pin needle will not engage and the trap pin will bias the needle to move into the open recess. Any of the optional or essential features defined in relation to any one aspect of the invention above may be applied to any further aspect, wherever practicable. Those optional feature combinations have not been explicitly repeated only for conciseness. Workable embodiments of the invention are described in further detail below, by way of example only, with reference to the accompanying drawings, of which: Figure 1 shows a perspective view of the lock assembly Figure 2 shows a perspective view of the plug Figure 3 shows a cross-sectional view of the plug Figure 4 shows a perspective view of the body Figure 5 shows a cross-sectional view of the body Figure 6 shows a perspective view of the house member and first trap Figure 7 shows a perspective view of the security pin Figure 8 shows a perspective view of the lock pin Figure 9 shows a perspective view of the second trap Figure 10 shows a perspective view of the key Figure 11 shows a cross-sectional view of the lock assembly Figure 12 shows a perspective view of the lock assembly without the house member or body Figure 13 shows a schematical operation of the first trap Figure 14 shows a schematical operation of the second trap Figure 15 shows an alternative embodiment of the security pin Figure 16 shows a perspective view of a pin shield. Figure 17 shows another embodiment of the security pin. Figures 18 and 19 shows another embodiment of the lock assembly. Figure 20 shows a schematical representation of the lock assembly of figures 18 and 19. Figure 21 shows a perspective view of the lock assembly of figures 18 and 19.

Detailed description of figures Figure 1 shows a pin tumbler lock assembly 10 comprising a plug 100, body 200, house member 300, and lock mechanism. The house member 300 is located within the body 200 and fixed thereto. The plug 100 is rotatably located in the house member 300 through a longitudinal axis. The lock mechanism comprises a plurality of pin tumblers which allow the lock assembly to move between a locked and unlocked condition. The pin tumbler lock mechanism will be understood by the skilled person and its operation will not be described for brevity. Plug The plug 100 is shown in figures 2 and 3 and has a cylindrical body 110 that extends along the longitudinal axis, having an outer surface 111 extending substantially the entire circumference. One end of the body has a keyway 112. The plug 100 also has pin tumbler channels 113 to receive pin tumblers from the lock mechanism. A plurality of security channels 114 are arranged along the longitudinal axis of the plug 100, each security channel 114 extends from an opening in the keyway 112 to the outer surface 111. In this embodiment, there are five security channels 114; however, there may be any number of security channels 114. The security channel has an internal circumferential ledge 115 which separates it into first 116 and second 117 parts, the first part 116 having a greater diameter than the second part 117. The circumferential ledge 115 defines a step between the first and second parts, the purpose of which is explained below. The plug 100 also has five lock channels 118 orientated substantially perpendicularly to the security channels 114. Each lock channel 118 has an opening at the outer surface which extends to an opening at the mid-point of the security channel 114. Looking at figure 3, the lock channel 118 is offset from the longitudinal axis (i.e., it does not extend radially from the longitudinal axis). The lock channel also has first and second parts, the first part being open at the outer surface 111, the second part tapers between the first part and security channel 114. Specifically, the second part is open at security channel 114, adjacent to the circumferential ledge 115. The plug further comprises recesses 122 located on the outer surface 111 that are both aligned with the security channels 114 along the longitudinal axis. Both recesses 122 have an arched shape, forming a quadrant of a circle. The arches sweep in different directions such that the recesses 122 are oriented differently. The plug has a pawl body 130 located at the opposite end to the keyway 112. The pawl body 130 is used to actuate an external body such as a door lock (not shown) in a way that will be known to the skilled person. The plug comprises a recess 120 in the outer surface 111 for receiving a fixing plate, (not shown). The fixing plate is attached to the plug once the security pins are in the security channels. For the purposes of this application, the fixing plate is to be construed as the part of the outer surface 111 of the plug 100. Body As shown in figure 4, the body 200 has cylindrical 210 and undercarriage 220 portions. The cylindrical portion 210 has a body channel extending along the longitudinal axis (the same longitudinal axis defined on the plug). There are first and second openings at each end of the channel; the first opening being smaller than the second. The cylindrical 210 and undercarriage 220 portions have different lengths along the longitudinal axis, with the undercarriage portion 220 being longer such that it appears to protrude at the second end. The undercarriage portion 220 has a recess defining a seat 221. Best shown in figure 5, the undercarriage portion 220 has pin tumbler channels 213 that correspond to the equivalent pin tumbler channels 113 on the plug 100. The pin tumbler channels 213 are radially offset from the longitudinal axis. The undercarriage portion 220 has a plurality of first trap channels 212 extending radially from the longitudinal axis. In the embodiment shown the pin tumbler 213 and first trap channels 212 run parallel to each other; however, in other embodiments they may be angled. A side wall of the undercarriage portion 220 comprises second trap channels 222 which extend to first trap channel 212. Hence the first and second trap channels are perpendicularly arranged. House member The house member 300 is shown in figure 6 and has a substantially tubular body, being open at both first and second ends. The second end has a lip 303 extending radially outwards from the longitudinal direction. The lip 303 has a protrusion 304 that corresponds to the seat 221 of the body 200. The house member has three sets of channels, trap channel 312, pin tumbler channels 313 and lock channels 318; all corresponding with the equivalent channels of the body and plug and are aligned when the lock assembly is arranged. The inner surface of the house member has a plurality of formations that extend radially towards the longitudinal axis. Specifically, first formations 330 which extend substantially around the circumference of the inner surface. Second formations 331 are thickened regions located in the regions of the trap channel 312 and pin tumbler channels 313. The first 330 and second 331 formations have the same thickness and are shaped to abut the outer surface 111 of the plug 110 when inserted. The formations help maintain the position of the plug 100 inside the house member 300, but also allow it to rotate. In between the first formations 330 are gaps 333 which extend to the outer surface 111 of the plug 100. A first trap 340 is pivotally mounted in each of the first formations; having a first 341 and second 342 gate. Each gate has pawl 343, and the gate is biased towards the plug. The pawl 343 is flush with the first 330 and second 331 formations when pointed towards the longitudinal axis. Security pins The security pin 400 are shown in figure 7, having first 410 and second 420 members. The security pins 400 are elongated and movable in the security channels 114 of the plug 100, each security channel 114 having a security pin 400. The first member 410 has an engagement member in the form of a plurality of ridges 411 that extend circumferentially, and an abutment that engages with the step of the plug 100 such as to prevent the first part falling into the keyway 112. The second member 420 has a protrusion 421 configured such to extend away from the outer surface 111 (either above or below) by a preselected distance. In the embodiment shown, the protrusion 421 for each of the security pins 400 is unique, having different lengths, diameters, or shapes. The purpose is to differentiate the security pins from one another to increase the difficultly of attacking the lock assembly. The second member 420 has a lip 422 that abuts the abutment 412 of the first part 410. A bias member (i.e. a spring; not shown) is located in the security channel 114, around the second member 420 pressing against the outer surface, biasing the security pin 400 towards the longitudinal axis. The lock pin A lock pin 500 is shown in figure 8 and has first 510 and second 520 parts and is located and movable in the lock channels 118, 318 of the plug 100 and house member 300 in use. The first part 510 has an engagement member in the form of a needle 511 that is selectively engageable with the ridges 411 of the security pin 400. The lock pin 500 is biased into engagement with the security pin 400, using a spring (not shown) located in a recess of the second part 400. The first part 510 has a surface 512 that corresponds to the shape of the outer surface 111 of the plug 100 such as to be substantially flush in use. As explained below, when the plug 100 rotates, the surface 512 engages with the first formations 330 of the house member 300 such as to maintain the position of the first part 510 in the plug 100. The second part 520 is configured to engage with the first part 510 in a first condition (explained below). The second part 520 is generally located in the second formation 331 of the house member 300. Second trap mechanism The second trap 600 is shown in figure 9, and has a trap pin 601, trap-pin lock 602, and spring 603. The trap pin 601 is elongate and has a plurality of asymmetrical teeth 604 that are partially tapered. The trap pin 601 is locatable and movable in the trap channels 212, 301 of the body 200 and house member 300. The trap-pin lock 602 has pawl 605 that is engageable with the asymmetrical teeth 604. The pawl 605 is arranged to permit the trap pin 601 to travel in a direction towards the plug, but prevents movement in the opposite direction. The trap-pin locks 602 are locatable in the second trap channels 222 and are fixed in position. The spring 603 is arranged to bias the trap pin 601 towards the plug 100. The key The key 700 is shown in figure 10 and has a first profile 701 for engaging with the pin tumblers of the lock mechanism and will be understood by the skilled person. The key also has a second profile 702 for engagement with the security pins 400. The first 701 and second 702 profiles are perpendicular to each other. Arrangement Figure 11 shows a sectional view of the lock assembly 100 with the components. The orientation of the plug in the body and house member defines a first condition. In this condition, both the first 510 and second 520 parts of the lock pins are in direct engagement with each other. Similarly, the driver and key pins of the lock mechanism are also in engagement with each other. The second condition is defined where the first 510 and second 520 parts of the lock pins are rotated out of engagement. As shown, the security pin 400 is substantially perpendicular to key pins 11 and lock pins 500. The security pin 400 is radially located between the first and second gates of the first trap. It should be understood, a gap is located between the outer surface 111 of the plug 100 and the inner surface of the house member 300, where the first 330 and second 331 formations maintain the position of the plug 100 inside the house member 300. The gap provides space for the security pin 400 (specifically the protrusion member 421) and the trap pin 601 to extend into. The trap pin 601 is located between the second gate 342 and the driver pins (not shown). Although not seen in figure 11, the first formations are located adjacent to the gaps around the house member and configured such that when the plug is in the second condition, the position of the first part 510 of the lock pin 500 is fixed in position within the plug 100, meaning that the needle 511 cannot ride over any of the ridges 411 and prevents the security pin 400 from moving in the security channel. If the security pin 400 is protruding when the plug is rotated from the first position, it will remain protruding until it is rotated back to the first condition (and the key is withdrawn). Similarly, if the security pin 400 is recessed/sunk in the plug when rotated from the first condition, it will remain recessed/sunk until the plug is rotated back to the first condition (and key is withdrawn). The key cannot be withdrawn when in the second condition as the security pins are fixed and prevent its removal. Figure 12 shows a perspective view of the lock assembly without the house member and body. The plug is in the first condition, located between the first and second gates. As shown, there are five lock pins, security pins and trap pins. The figure also shows a flexi-fake pin 703 in each of the first and second recesses. Each flexi-fake pin 703 is pivotally mounted to the plug and partially protrudes from the recesses. As mentioned, the recesses are oriented differently to each other such that the flexi-fake pins 703 appear upside-down. The flexi-fake pins 703 are configured to engage with the pawls 343 of the first 341 and second 342 gates upon rotation. The purpose of the engagement is to confuse any would-be lock picker. Operation The operation of the lock assembly will be described with reference to figures 13 and 14. The lock assembly 10 is configured such that if the plug 100 is rotated away from the first condition without the correct key, the first 340 and/or second 600 traps will restrict and/or prevent further rotation, including preventing the plug 100 returning to the first condition. The lock assembly 10 is then immobilised, and no further attacks are possible. Figure 13a-c and 14 show a schematical representation of the operation of the lock assembly 10 when either being attacked, or when an incorrect key is inserted. Figure 13a shows the plug in the first condition, where the security pins are movable in the security channel. When a key is inserted into the keyway, the security pins will move such that they are either protruding, flush or recessed with respect to the outer surface of the plug. If the security pin is protruding or recessed, then this indicates that the lock has been attacked or the incorrect key inserted. Only the insertion of the correct key will move all the security pins to being flush. As the security pin moves, the lock pin will ride over the ridges providing there is a sufficient gap between the plug and house member. The key 700 has moved the security pin 400 to protrude from the plug 100 in figures 13a-c. The first 341 and second 342 gates of the first trap are pivotally mounted to the house member 300 and their pawls are configured to engage with the security pin 400 when it protrudes from the outer surface. Each gate permits rotation of the plug in a single direction only; the first gate 431 allowing for rotation in the clockwise direction and the second gate 342 allows for rotation in the anti- clockwise direction. Figure 13b shows the plug rotating from the first condition. The lock pin 500 is prevented from moving by the first formation 330. This means that the security pin 400 is now fixed to protrude from the plug as the needle cannot ride over the ridges. As explained below, the orientation is defined as an ‘actuated position’ in that the trap mechanism (eg. the gates) prevent the plug rotating back to the first condition. As the plug rotates, the gate 341 will pivot such as to allow the security pin 400 (and therefore the plug to rotate through); however, when the plug is subsequently rotated back towards the first condition, the pawl will form a force path through the security pin and prevent the plug from rotating in this direction (figure 13c). If the security pin 400 is protruding and rotated past the second gate 342 instead (i.e. in the anti-clockwise direction with respect to figures 13), the security pin 400 will not be able to rotate past the trap pin (not shown) and the rotation of the plug 100 will be restricted to the angles between the second gate and trap pin. Importantly, whether rotated in either direction, the plug 100 cannot return to the first condition and thus the lock assembly 10 is permanently immobilised. This means that a lock picker only has one attempt to pick the lock assembly 10. The operation of the second trap is shown in figure 14 in a second actuated orientation. The components of the plug and pins are the same as above. However, in this condition the security pin 400 is “sunk” with respect to the outer surface and forms a recess in the plug. Once rotated from the first position, the lock pin 500 is held in position by the first formation 330 in the same way described above. If the plug 100 is rotated such that the recess is in alignment with the trap pin 601, the trap pin 601 will move into the recess and prevent further rotation. Again, the lock assembly 10 is permanently immobilised and therefore further attacks are not possible. When the correct key 700 is inserted, the protrusion moves to (or stays in) a position such that it is substantially flush (or level) at the outer surface 111 of the plug 100. The protrusion need not be exactly flush with the outer surface 111 (i.e. have a curved shape, or be completely level), just so along as it does not engage with the first trap 340, or forms a sufficiently recess for the trap pin 601 to move into. In this condition, the security pin 400 will not engage with either the first 340 or second 600 traps in a way that will prevent or restrict further rotation of the plug and will allow the plug 100 to return to the first condition (however they may come into contact on rotation). It should be understood that in order for the plug to rotate at all, all of the pin tumbler pins will need to be at the correct position (i.e., the key and driver pins engaged at the shear line), irrespective of the position of the security pins 400. Thus, the security pins 400 add an additional layer of security over a conventional lock. Making the security pins 400 and pin tumblers perpendicular to each other increases the difficulty of picking the lock assembly 10. As shown in figure 12, the pawls of each gate are bridged together meaning that only one security pin 400 needs to be protruding in order to provide the force path and prevent rotation. In other embodiments however, the pawls of each of the first 341 and second 342 traps may be independent from one another. In operation, each of the security pins 400 will be protruding, flush or sunk independently of the other security pins 400. If only one of the security pins 400 is protruding or sunk, then the trap mechanism will immobilise the lock assembly 10 (i.e., regardless of whether all of the other security pins are flush). Figure 15 shows an alternative embodiment of the security pin 800 being a unitary part, i.e. not having first and second members as described in figure 7. Figure 16 shows a pin shield 900 that can be used in some embodiments to protect the security pins. In use the pin shield 900 is locatable in the security channel along with the security pin. The security pin is able to freely to move through the aperture of the pin shield 900. The pin shield 900 has a lip 910 that extends around the tubular body as shown the lip has a sloped portion 911. The pin shield 900 increases the pick resistance as the lip 910 (i.e. the sloped portion thereof) is configured to be of sufficient size to prevent picking tools being inserted through the security channel, meaning the lock picker is unable to gain additional information about the lock Furthermore, the pin shield 900 protects the spring used to bias the security pin (towards the keyway) from being over compressed, thereby extending the life of the lock mechanism 100. A unitary security has more supports to enable the correct orientation at any position. Furthermore, the unitary security pin is better designed and is easier to manufacture. Figure 17 shows an alternative embodiment of the security pin 1000 for use in the lock assembly shown in figures 18 and 19. Unlike the previous embodiments, the ridges 1011 only partially extend around the surface of the security pin 1000, i.e. around 180 degrees, although they can extend anywhere between 10 to 270 degrees. The ridges 1011 have the same purpose as the previous embodiments, i.e., to engage with the lock pin such as to lock the position of the security pin 1000 when the plug 100 is rotated. Two guides 1030 are configured to locate into corresponding shaped grooves in the security channel 1115 to prevent the security pin 1000 rotating in the security channel 1115. The security pin 1000 comprises an open recess 1031, substantially opposite to the ridges 1011. A second engagement member 1032 is in the recess and forms a protrusion, which comprises an engagement surface being substantially flush with the outer surface 1033 of the security pin 1000. The engagement surface is comprised from two angled surfaces which form an apex or intersecting edge. However, the surface can be arched having the same radius as the outer surface 1033. As shown in figure 18 the second engagement member 1032 corresponds to the engagement member 1210 on the check pin 1200, e.g., the check pin needle 1210. This orientation is the first condition as described in the previous embodiments. As will become apparent, when the security pin 1000 is in the correct position within the security channel 1115 (i.e., when using the correct key), the check pin needle will 1210 engage with the second engagement member 1032 (the engagement surface thereof) of the security pin 1000 such as to prevent the needle 1210 from locating into the open recess 1031 and will allow continued operation of the lock assembly. Figure 19 represents an ‘actuated orientation’ of the lock assembly in the second condition in which only the correct position of all security pins 1000 in their respective security channels 1115 will allow the plug 100 to continue to rotate (i.e. remain operable) where the check pin 1200 is aligned with the trap pin 600. Figure 19 shows an example where the correct key 700 is being used. In this actuated orientation, the check pin 1200 is movable within the check pin channel 1220 owing to the alignment of the engagement pins 1300 (explained below). The trap pins 600 are the same as the previous embodiment and are biased towards the plug by springs 603, which cause the trap pins 600 to engage with the check pins 1200. However, engagement between the second engagement member 1032 and check pin needle 1210 prevents movement of both the trap 600 and check pin 1200, meaning the trap pin 600 doesn’t enter/protrude into the plug 100. Hence the plug can continue to rotate out of the actuated orientation (and back into the first condition) such that the check pin 1200 and trap pin 600 are no longer in direct engagement. However, if the security pin 1000 is in the incorrect position (i.e., by using the wrong key or incorrectly picked), the second engagement member 1032 will not align with the check pin needle 1210 in the actuated orientation. The bias force will move the check pin needle 1210 into the open recess, providing enough space in the check pin channel 1220 for the trap pin 600 to move into the plug. Once this has occurred the plug is prevented from further rotation and the lock assembly is irrevocably locked (i.e., the spring moves both the trap pin and check pin towards the security pin). In broad terms, in the actuated orientation a force path exists between the trap 600, check 1200 and security 1000 pins regardless of whether the correct key 700 is inserted or not. If the incorrect key is inserted (or the lock assembly is incorrectly picked), an additional force path exists between the trap pin 600 and plug 100 which prevents rotation. The key 700 determines the position of the security pin 1000 in the security channel 1115, specifically, the height of the bitting for the specific security pin 1000. The key bitting directly engages and moves the security pins 1000 as its inserted. The spring 1040 biases the security pin into engagement with the key bitting. Hence only the correct bitting will ensure the second engagement member is aligned with the check pin needle 1210. Figure 20 shows a schematical representation of the lock assembly in the actuated orientation when using the (a) correct key 710 and (b) incorrect key 720. In (a), the key bitting moves the security pin 1000 into the correct position such that the second engagement member 1032 engages with the check pin needle 1210 and therefore the check pin 1200 remains stationary/fixed in the check pin channel 1220 and prevents the trap pin 600 from moving into the plug 100. In (b), the incorrect key bitting means the security pin is in the incorrect position and hence the second engagement member 1032 doesn’t engage with the check pin needle 1210 which then moves into the open recess 1031, providing enough space for the trap pin 600 to move into the plug and will prevent any further rotation. Figure 21 shows the side view of the lock assembly when the correct key is used (both the plug and body member are hidden). Each security pin 1000 is unique, for example having different lengths and ridge configurations (i.e., the position and number of ridges differs on each security pin). Each key bitting of the correct key 710 pushes against the spring bias to move the security pin into the correct position in the security channel. It should be understood that only one ridge on each security pin 1000 corresponds to the correct position, meaning that if the plug is rotated into the actuated position where the lock pin is engaged to an incorrect ridge, then trap pin will be able to move into the plug and render the lock as permanently inoperable. Only one security pin 1000 needs to be incorrectly positioned for the lock to become inoperable. Increasing the number of security pins 1000 and ridges 1011 on each pin increases the difficulty of picking the lock assembly. However, as shown on figure 20, the middle security pin 1050 only has one ridge which is counter intuitive. The purpose of this security pin is to mitigate the risk of the lock becoming inoperable by inserting an incorrect key or by picking. If the lock pin isn’t engaged into a ridge, it will protrude out of the plug 100 (e.g. the lock channel) and into the housing (in the first condition). This defines a force path between the housing and plug and therefore the plug can’t rotate. Hence, the middle security pin 1050 having a single ridge 1051 ensures that only keys having the same middle bitting as the correct key will rotate the lock. Whether the lock assembly will permanently lock in the actuated orientation will depend on the other four security pins being correctly aligned. If the middle bitting of the key is incorrect, the plug won’t rotate and therefore can’t be rotated into the actuated orientation described above (thereby preventing the lock becoming permanently locked) but also preventing the lock assembly from unlocking. It should be understood that the single-ridged pin is not essential to the invention, nor does it have to be the middle pin. The check pin 1220 has a body portion which is hyperboloidal shaped for engagement with an engagement pin 1300. The purpose of the engagement pin 1300 is to maintain the position of the check pin when rotated from the actuated orientation. Only when the plug is rotated into the actuated orientation can the check pin 1200 move within the check pin channel 1220. This is because the engagement pin 1300 is comprised of first 1301 and second 1302 parts which only engage in the actuated orientation such as to allow the engagement pin 1300 to move. When the first 1301 and second 1302 parts are not engaged (like shown in figure 18) the first part has a surface which is flush with the outer surface of the plug and therefore held in position against the body (thereby maintaining the position of the check pin). Because the spring force acting on the trap pin 600 is greater than the spring force acting on the engagement pin 1300, movement of the trap pin 600 (and therefore check pin 1200) will overcome the bias on the engagement pin 1300. So, if the security pin is incorrectly positioned, the first and second parts of the engagement pin 1300 with move towards the housing. The hyperboloidal body of the check pin 1200 therefore converts the vertical linear motion of the trap pin into horizontal linear motion on the engagement pin 1300 (i.e. perpendicular translation of linear motion). Notable differences between this embodiment from the earlier ones is lack of a house member 300. In the later embodiment, the security pin 1000 doesn’t have to protrude from the plug and so there isn’t need for a gap between the plug and body, meaning that the house member 300 is not needed. The security channel is not open and is instead covered by a closed plate. The benefit of the latter embodiment is that the pin tumbler mechanism of the lock mechanism is no longer required, reducing the complexity of the design and ease of manufacture. Referring to Figure 18, an air gap 1400 exists between the check pin needle 1210 and second engagement member 1032 when not in the actuated orientation. The purpose of the air gap 1400 is to prevent engagement of the check pin and the second engagement member which would otherwise assist lock pickers determining the position of the security pin 1000 within the security channel 1115 (i.e. if in the correct position or not). The engagement pin 1300 (i.e the first part 1301) maintains the position of the check pin 1200 as the plug rotates and ensures the presence of the air gap 1400. Only in the actuated orientation will the engagement pin 1301 allow movement of the check pin 1200. When rotated away from the actuated position (and using the correct key) the engagement pin 1301 pulls the check pin 1200 out of engagement with the second engagement member 1032 reforming the air gap. Specifically, the first engagement pin 1301 is moved by the body once rotated away from the actuated orientation such that its pointed end 1305 engages with the hyperboloidal check pin body to move in the check pin channel and forms the air gap 1400. The various pins of the lock assembly are constructed such that they only engage with the correct channels and/or pins they are associated with. For example, the check pin 1200 will not locate into the lock pin channel in the body portion, or lock pin 500 will not locate into the engagement pin channel. This can be achieved by configuring the shape, size and/or position of the pins to only engage with the correct channels or pins. The check pin 1200 is hyperboloidal shaped in this embodiment, however, it may be differently shaped in other embodiments, for example, it may be substantially cylindrical, tubular, or cuboidal shape. Such embodiments have an engagement member, such as notch/or pointed region, for engaging with the engagement pin to provide the functions described above.

Claims

Claims 1. A lock assembly having, a body member, a plug located at least partially in the body member and rotatable with respect thereto, the plug comprising a security channel and a corresponding lock channel that is offset from the security channel and extends into the security channel, a security pin located and movable within the security channel, and a lock pin located and movable within the lock channel, the lock pin being biased to engage to the security pin and configured to selectively lock the position of the security pin in the security channel, a trap mechanism configured to selectively allow or restrict rotation of the plug depending upon the position of the security pin in the security channel.

2. A lock assembly according to claim 1, having a first condition where the security pin is movable in the security channel, and a second condition where the security pin is locked in position in the security channel.

3. A lock assembly according to claim 2, wherein the first condition corresponds to when the plug and body member are at a specific rotational orientation with respect to one another, and the second condition corresponds to the plug being rotationally offset from the first condition.

4. A lock assembly according to claim 3, comprising one or more actuated orientations in the second condition, where the trap mechanism is actuated to restrict the rotation of the plug when the security pin is in an incorrect position in the security channel.

5. A lock assembly according to claim 4, where the trap mechanism substantially inhibits any further rotation of the plug.

6. A lock assembly according to any of claims 4 or 5, the lock pin arranged to permit the security pin to move between correct and incorrect positions in the security channel in the first condition and lock the position of the security pin in the second condition.

7. A lock assembly according to claim 6, the lock pin having an engagement member for engaging with two or more corresponding engagement members on the security pin.

8. A lock assembly according to claim 7, the engagement member of the lock pin has a needle or pointed edge or end, and each of the corresponding engagement members on the security pin being a ridge.

9. A lock assembly according to claim 8, where one ridge corresponds to the correct position, and at least one ridge corresponds to the incorrect position.

10. A lock assembly according to claim 2, the lock pin having first and second separate parts being engaged in the first condition, and not engaged in the second condition.

11. A lock assembly according to claim 10, the first part being substantially located in the plug, the second part substantially located in the body member.

12. A lock assembly according to claim 10 or 11, the first part is arranged such that in the second condition its position is fixed with respect to the plug, the needle/edge preventing the security pin from moving in the channel.

13. A lock assembly according to any one of claims 2-12, the lock pin being biased into engagement with the security pin in the first condition.

14. A lock assembly according to claim 13, a bias force acting on the security pin such as to bias the pin towards a keyway, where the bias force acting on the security pin is greater than the bias force acting on the lock pin.

15. A lock assembly according to claim 8 or 9, the security pin comprising an open recess in its outer surface, a second engagement member is located in the recess.

16. A lock assembly according to claim 15, further comprising a check pin located in a check pin channel being configured to provide a force path to between the trap mechanism and security pin in the actuated orientation.

17. A lock assembly according to claim 16, the check pin comprising an engagement member configured to engage with the second engagement member.

18. A lock assembly according to either claims 16 or 17, the check pin is axially movable within the check pin channel in the actuated orientation.

19. A lock assembly according to claim 18, where the trap mechanism is configured to locate into the check pin channel in the actuated orientation.

20. A lock assembly according to any of claims 16-19, where the check pin channel is perpendicular to the security pin channel.

21. A lock assembly according to claim 1, having a plurality of security channels and corresponding lock pin channels in axial alignment through a longitudinal axial direction of the plug, each security channel and lock pin channel housing a security pin and lock pin respectively.

22. A lock assembly according to claim 7 and 21, wherein at least one security pin comprises a single ridge for engaging with a corresponding lock pin, where the ridge corresponds to the correct position.

23. A lock mechanism according to any of claims 4-22, where the plug is substantially the same diameter as the internal diameter of the body member such that there is no gap between the body member and plug.

24. A lock mechanism according to any of claims 4-22, where the body member comprises a house member fixed thereto, the house member having a tubular body for receiving the plug.

25. A lock assembly according to claim 24, the trap mechanism having a first trap configured to engage with the security pin in an actuated orientation when the security pin protrudes above the outer surface.

26. A lock assembly according to claim 25, the first trap having at least one gate configured to permit rotation of the plug in a first direction and restrict or inhibit rotation in the opposite second direction.

27. A lock assembly according to claim 26, wherein the first trap has first and second gates, wherein the first gate is configured to permit rotation of the plug in a first direction and restrict or inhibit rotation in the opposite second direction, the second gate configured to permit rotation in the second direction and restrict or inhibit rotation in the first direction.

28. A lock assembly according to claims 26 or 27, wherein at least one gate is pivotally mounted to the house member.

29. A lock assembly according to any of claims 25-28, the trap mechanism having a second trap configured to engage with a recess of the plug formed by the security channel and security pin when the security pin moves into the plug by a preselected distance from the outer surface when in an actuated orientation.

30. A lock assembly according to claim 29, the second trap having at least one trap pin.

31. A lock assembly according to claim 30, the at least one trap pin comprises a plurality of asymmetrical teeth and trap-pin lock having a pawl for engagement with the asymmetrical teeth.

32. A lock assembly according to any of claims 24-31, a lock mechanism comprises a pin tumbler lock having a plurality of tumbler pins, the plug having a keyway suitable for receiving a key for engagement with the pin tumblers.

33. A lock assembly according to claim 32, the security pin and pin tumblers being arranged perpendicularly.

34. A key suitable for use with a lock assembly of any of claims 32-33, having a first profile for engagement with the security pin and a second profile for engagement with the lock mechanism.

35. A key according to claim 34, where the first and second profiles are perpendicular.

36. A lock assembly having, a house member, a plug located at least partially in the house member and rotatable with respect thereto, having, an outer surface, at least one security channel being open at the outer surface, at least one security pin located in the security channel and configured to be movable with respect thereto, a lock mechanism selectively operable to move the lock assembly between a locked and unlocked condition, a trap mechanism configured to render the lock assembly inoperable by restricting the rotation of the plug by engaging with the security pin when the security pin moves a specified distance from the plug’s outer surface.