A door locking mechanism for a vehicle

Abstract

A door locking mechanism for a vehicle includes a bolt 210 having a free end 212 and a connecting end (213, fig 2). It also has an actuator (220, fig 2) coupled to the connecting end of the bolt and

Description

TECHNICAL FIELD The present disclosure relates to a door locking mechanism for a vehicle. Aspects of the invention relate to a vehicle sub-assembly comprising the door locking mechanism and a vehicle comprising the sub-assembly. BACKGROUND It is known to provide door locking mechanisms for road vehicles that comprise a latch and a strike plate. Typically, the strike plate is mounted to the B-pillar of the vehicle frame for engagement with the latch mounted to the door. ‘Soft close’ doors are known which pull the door into a final closed position when the latch contacts the strike plate. These systems allow a door to be closed with less force, but at the cost of increased electromechanical complexity. It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide a door locking mechanism for a vehicle, the locking mechanism comprising: a bolt having a free end and a connecting end; an actuator coupled to the connecting end of the bolt and arranged to move the bolt in a linear direction between an extended position and a retracted position; and a strike plate having a channel in which the free end of the bolt is receivable; wherein the bolt and actuator are configured for attachment to a body of the vehicle and the strike plate is configured for attachment to a doorofthe vehicle so that, when the bolt is in the extended position, the free end of the bolt is received in the channel of the strike plate to lock the door to the vehicle body. Optionally, the channel extends in a first direction and comprises an internal surface inclined at an oblique angle to the first direction. The bolt and strike plate may be arranged so that the bolt contacts the inclined surface when moving into the extended position. The actuator force is resolved through the inclined surface as the bolt moves therealong to urge the door in a direction normal to the surface. When installed on a vehicle, this can be used to pull the door into a final closed position, compressing a door seal, for example. Optionally, the bolt comprises a constant cross section along a portion of the length of the bolt, wherein the bolt moves a distance equal to or less than the portion of the length of the bolt as the bolt moves between the extended and retracted positions. In this way the bolt may pass through an aperture in the vehicle body as the bolt moves between the retracted and extended positions while maintaining a constant gap with an inner edge of the aperture. This removes any potential finger trap that could otherwise exist if the gap were to narrow as the bolt extends from the opening. Optionally, the free end of the bolt comprises a canted surface having a leading edge and a trailing edge; wherein the leading edge defines an edge of the canted surface furthest from the connecting end of the bolt, 1 and the trailing edge defines an edge of the canted surface relatively closer to the connecting end of the bolt than the leading edge; and wherein the portion of the length of the bolt comprising the constant cross section extends between the trailing edge and the connecting end; and, optionally, wherein the canted surface is a contoured surface. Optionally, the channel comprises an entrance section and an interior section, wherein the entrance section comprises the inclined surface so that the entrance section narrows from an opening to the entrance section to the interior section, and wherein the interior section has a constant cross section along the first direction. The interior section may provide a close fit to an exterior of the bolt to hold a vehicle door in the closed position. Optionally, the actuator is a linear actuator and comprises an actuator housing and an effector that extends from the housing to effect movement of the bolt between the extended and retracted positions. In this way the bolt and actuator form a simple mechanism with minimal moving parts. Optionally, the effector is coupled to the connecting end of the bolt by a pin joint. In this way the actuator does not have to be precisely located relative to the bolt as lateral movement of the effector during extension of the effector is accommodated by the pin joint. In an embodiment of the invention, the door locking mechanism further comprises a guide block, the guide block having an aperture in which the bolt is received to guide the bolt as it moves between the extended and retracted positions. In this way the bolt is simply supported throughout its range of movement. In an embodiment of the invention, the door locking mechanism further comprises a bed to which the bolt and actuator are fixable; and wherein the bed is configured for attachment to the vehicle body. In this way the locking mechanism may be partially assembled separate to the vehicle body for attachment to the vehicle body at a later stage of vehicle assembly. According to another aspect of the invention, there is provided a vehicle sub-assembly comprising the door locking mechanism, wherein the sub-assembly further comprises at least part of a vehicle body comprising a door surround, the door surround comprising an aperture from which the bolt extends during movement between the retracted and extended positions. Optionally, the aperture corresponds in size and shape to the constant cross section of the bolt so that substantially no gap exists between the bolt and an inner edge of the aperture. Therefore, an ingress point for debris is removed by tightly fitting the bolt within the aperture. By ‘substantially no gap’ it is meant that the gap may be less than 1 mm, or less than 0.5 mm, or less than 0.25 mm. In an embodiment, the vehicle sub assembly further comprises a door configured to overlap the door surround when the door is in a closed position, wherein the strike plate is positioned in the door to align the channel of the strike plate with the aperture of the door surround when the door is in the closed position. Optionally, when the door is in the closed position, the free end of the bolt is arranged to engage the internal surface of the channel as the bolt moves into the extended position; and wherein engagement of the free end of the bolt with the internal surface of the channel draws the door toward a vehicle centreline to compress a door seal. In this way, the action of the bolt engaging the strike plate draws the door into a final closed position in which a door seal is compressed. Optionally, when the bolt is in the retracted position, the free end of the bolt is flush with an external surface of the door surround. Therefore, the door surround is unencumbered with a door latch of any kind, removing a potential snagging point during ingress and egress of the vehicle. According to another aspect of the invention, there is provided a vehicle comprising the sub assembly. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in anyway and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a vehicle in accordance with embodiments of the invention; Figure 2 shows a locking mechanism for the vehicle in accordance with embodiments of the invention; Figure 3 shows a strike plate of the locking mechanism; Figure 4 shows a cross section through the strike plate and a bolt of the locking mechanism; Figures 5A and 5B show the bolt of the locking mechanism in an extended and retracted position, respectively; and Figure 6 shows the vehicle with the nearside front passenger door open. DETAILED DESCRIPTION The present disclosure relates to a door locking mechanism for a vehicle, a vehicle sub-assembly comprising the door locking mechanism and a vehicle comprising the sub-assembly. As used herein, the terms ‘x-direction’, ‘y-direction’ and ‘z-direction’ denote, respectively, a longitudinal direction, a transverse direction and a vertical direction. By ‘longitudinal direction’ it is meant a horizontal direction that extends between the front and rear of the vehicle, wherein the term ‘front of the vehicle’ is given its normal definition (i.e. the side of the vehicle facing the normal direction of travel). By ‘transverse direction’ it is meant a horizontal direction perpendicularto the longitudinal direction (i.e. a direction that extends between sides of the vehicle). The term ‘forward’ means in a direction toward the front of the vehicle. The relative terms ‘upper’ and ‘lower’ are used to mean relatively further from the ground and relatively closer to the ground, respectively. The term ‘front plane’ refers to a plane that lies across the y-direction and z-direction. The term ‘side plane’ refers to a plane that lies across the x-direction and z-direction. These terms when referring to components of the vehicle refer to the components as oriented when assembled to the vehicle unless otherwise stated. Figure 1 shows a vehicle 100 in accordance with an embodiment of the present invention. The vehicle 100 of Figure 1 is a passenger car, but may be any other type of vehicle to which embodiments described herein may apply such as a pickup truck, van or othertype of commercial vehicle. Embodiments of the present disclosure relate to a locking mechanism for a door 101 of the vehicle 100. In the illustrated example embodiments, the door 101 is a nearside front passenger door 101 (of a right-hand drive vehicle), meaning that the door 101 provides access to a front passenger seat of a passenger compartment of the vehicle 100. However, it will be appreciated that the locking mechanism and the vehicle sub-assembly comprising the locking mechanism may be used fora front passenger door 101 either side ofthe vehicle 100, and for other doors of the vehicle, such as rear passenger doors, a tailgate or a bonnet. As used herein, the term ‘vehicle body’ encompasses some parts ofthe vehicle 100 that make up the vehicle bodywork, which is to say, the (usually) painted exterior surfaces ofthe finished vehicle 100. The definition used herein includes exterior body panels, but excludes body closures such as the bonnet, the doors and the tailgate or boot. The term vehicle body also encompasses a vehicle frame, which is the structural part ofthe vehicle 100 to which other components ofthe vehicle 100 are attached, including the exterior body panels, the body closures, the powertrain, subframes for the wheel assemblies and suspension systems, and interior panels. Figure 2 shows parts of a locking mechanism 200 in accordance with an embodiment ofthe invention. The locking mechanism 200 comprises a bolt 210 and an actuator 220 configured for moving the bolt 210 in a linear direction in and out of engagement with a strike plate of the locking mechanism 200. The strike plate 280 is shown in figure 3. The bolt 210 comprises an elongate body 211. The actuator 220 is coupled to a longitudinal end 213 ofthe body 211 (herein referred to as the ‘connecting end 213’). The other longitudinal end (herein referred to as the ‘free end 212’) is disposed to engage the strike plate 280. The bolt 210 and actuator 220 are configured for attachment to the vehicle body and the strike plate 280 is configured for attachment to the door 101 ofthe vehicle 100. Figure 4 shows a cross section of parts of the locking mechanism including the bolt 210 and the strike plate 280. The cross section is taken in a side plane. While the bolt 210 and the strike plate 280 are shown in isolation of the vehicle body and the door 101 for simplicity, the bolt 210 and the strike plate 280 are shown aligned as if on the vehicle 100 with the door 101 in the closed position. The bolt 210 is shown in a retracted position in which the bolt 210 is out of engagement with the strike plate 280. The strike plate 280 comprises a main body 281 and a plate 282 that extends across one end of the main body 281. The plate 282 comprises an opening 283 fora channel 284. The channel 284 extends into the main body 281 in a first direction. By ‘first direction’ it is meant that when the strike plate 280 is attached to the door 101 and the door 101 is in the closed position the channel 284 extends substantially in the vehicle x-direction. The plate 282 provides a planar face of the strike plate 280 that faces the free end 212 of the bolt when the door 101 is in the closed position (as per the arrangement of figure 4). To engage the strike plate 280, the bolt 210 is advanced in the x-direction into an extended position in which the free end 212 of the bolt is received in the channel 284. With the bolt 210 received in the channel 284 the door 101 is locked to the vehicle body The channel 284 comprises an entrance section 285 and an interior section 286. The entrance section 285 comprises a taper that narrows from the opening 283 in the plate 282 to the interior section 286. In the illustrated embodiment, the entrance section 285 and the interior section 286 comprise a substantially quadrilateral cross-sectional shape in the front plane (when the door is closed). By ‘substantially quadrilateral’ it is meant that the cross-sectional shape comprises four planar sides, but that these sides may be joined by an inner radius or fillet as may be required by the manufacturing process. It will be appreciated that in other unillustrated embodiments the cross-sectional shape may be other than quadrilateral, such as a circular shape or a shape with rounded sides. In the illustrated embodiment, the quadrilateral cross-sectional shape of the interior section 286 and the dimensions thereof are substantially the same as the cross-sectional shape of a portion of the bolt 210 that is received in the interior section 286. By ‘substantially the same’ it is meant that the bolt 210 fits within the interior section 286 with only a manufacturing tolerance of clearance between the outer surface of the bolt 210 and the inner surface of the interior section 286. In this way, when the bolt 210 is received in the interior section 286, the bolt 210 holds the door 101 in the closed position with little or no play. The bolt 210 is configured for extension from an aperture 311 in the vehicle body 300 as illustrated in figures 5A and 5B. Figure 5A shows a portion of the vehicle body 300 with the aperture 311 and the bolt 210 in the extended position. Figure 5B shows the same portion of the vehicle body 300 with the aperture 311 and the bolt 210 in the retracted position. Except for the bolt 210, those parts of the locking mechanism 200 shown in figure 2 are concealed behind the vehicle body 300 so as not to be visible during normal use of the vehicle 100. Figure 6 shows part of the nearside of the vehicle 100 with the nearside front passenger door 101 open. The vehicle body 300 comprises a door surround 310. The door surround 310 extends between interior surfaces and exterior surfaces of the vehicle 100 and comprises the surfaces of the vehicle body 300 that are concealed when the door 101 is closed and visible to an operator of the vehicle 100 when the door 101 is open. A seal 312 is provided around at least part of the door surround 310 to seal the interior of the vehicle 100 from water and other weather when the door 101 is closed. The aperture 311 is provided in a forward-facing surface 313’ of a rear side 313 of the door surround 310. The strike plate 280 is provided in a rear-facing surface 102’ of a rear side 102 of the door 101 that overlaps the forward-facing surface 313’ of the door surround 310 when the door 101 is in the closed position. The strike plate 280 is positioned in the door 101 to align the channel 284 of the strike plate 280 with the aperture 311 of the door surround 310 when the door 101 is in the closed position. The tapered entrance section 285 of the channel 284 comprises four internal surfaces 2851,2852,2853, 2854 (labelled in figure 3) inclined at an oblique angle to the first direction. Prior to extension of the bolt 210, should the bolt 210 not be exactly aligned with the interior section 286 of the channel 284 when the door 101 is in the closed position, extension of the bolt 210 into the channel 284 will cause the free end 212 of the bolt 210 to contact one or more of the inclined surfaces 2851, 2852, 2853, 2854 of the entrance section 285 when advancing therethrough. The actuator force pushing the bolt 210 into the channel 284 is resolved through the inclined surface contacted by the bolt 210 to urge the door 101 in a direction normal to the surface. This urging of the door 101 can be used to pull the door 101 into a final closed position in which the bolt 210 is exactly aligned with the interior section 286 of the channel 284 for being received therein. In some embodiments, the locking mechanism 200 may be configured so that the free end 212 of the bolt 210 contacts the outward facing surface 2853 of the internal surfaces 2851, 2852, 2853, 2854 during extension of the bolt 210 through the entrance section 285. By ‘outward facing surface 2853’ it is meant a surface that faces away from the vehicle centreline C-C when the door 101 is closed. Engagement of the free end 212 of the bolt 210 with the outward facing surface 2853 of the entrance section 285 draws the door 101 toward the vehicle centreline C-C as the bolt 210 is extended. In this way, the action of the bolt 210 engaging the strike plate 280 draws the door 101 into a final closed position to compress the door seal 312. It will be appreciated that while in the illustrated embodiments the entrance section 285 comprises four inclined internal surfaces, in other unillustrated embodiments the entrance section 285 comprises fewer than four inclined surfaces and, in some embodiments, only a single inclined surface. In one embodiment, where a single inclined surface is provided, the single inclined surface may be the outward facing surface 2853 of the entrance section 285 and the bolt 210 may be configured to engage the outward facing surface 2853 as it moves into the extended position to draw the door 101 into the final closed position and compress the door seal 312. When the bolt 210 is in the retracted position, the free end 212 of the bolt 210 is flush with the forward-facing surface 313’ of the door surround 310. In this way, the door surround 310 is unencumbered with a door latch of any kind, removing a potential snagging point for a user of the vehicle 100 when they enter and exit the vehicle 100 past the door surround 310. The cross-sectional shape of the bolt 210 body 211 in the front plane is constant along a portion of the length L of the body 211 (the portion of the length L being shown in figure 4). The actuator 220 is configured to move the bolt 210 between the retracted and extended positions a distance equal to or less than the portion of the length L of the bolt 210 having the constant cross section. In this way, the bolt 210 may pass through the aperture 311 in the vehicle body 310 as the bolt 210 moves between the retracted and extended positions 6 while maintaining a constant gap with an inner edge 311 ’ of the aperture 311. This removes any potential finger trap that could otherwise exist if the gap were too narrow as the bolt 210 extends from the aperture 311. The aperture 311 corresponds in size and shape to the constant-cross section of the portion of the length L of the bolt 210 so that substantially no gap exists between the bolt 210 and the inner edge 31T of the aperture 311. In this way, an ingress point for debris is removed by tightly fitting the bolt 210 within the aperture 311. By ‘substantially no gap’ it is meant that the gap is less than 1 mm, or less than 0.5 mm, or less than 0.25 mm. In some embodiments, the forward-facing surface 313’ of the door surround 310 is contoured and the free end 212 of the bolt 210 is correspondingly contoured to match the contours of the forward facing surface 313’ of the door surround 310. In the illustrated embodiments, the free end 212 of the bolt 210 is canted to match the angle of the forward facing surface 313’ of the door surround 310. The cant provides the free end 212 with a leading edge 212’ and a trailing edge 212”, the leading edge 212’ defining an edge of the free end 212 furthest from the connecting end 213 of the bolt 210, and the trailing edge 212” defining an edge of the free end 212 relatively closer to the connecting end 213 of the bolt 210 than the leading edge 212’. In the illustrated embodiment, the free end 212 is canted rearward so that the leading edge 212’ is a lower edge of the free end 212 and the trailing edge 212” is an upper edge. The portion of the length L of the bolt 210 comprising the constant cross section extends between the trailing edge 212” and the connecting end 213. This means from the trailing edge 212” across the portion of the length L of the bolt 210, the cross section of the body 211 of the bolt 210 is constant. This means that the gap between the outer surface of the bolt 210 and the inner edge 311’ of the aperture 311 is constant across the full range of movement of the bolt 210. With reference again to figure 1, the actuator 220 comprises an actuator housing 221 and an effector 222 that extends from the housing 221 to effect movement of the bolt 210 between the extended and retracted positions. The actuator 220 is a linear actuator, meaning that the effector 222 follows a straight line in the x-direction (hereinafter referred to as the line of actuation) as it extends from the actuator housing 221. The effector 222 is coupled to the connecting end 213 of the bolt 210. The actuator 220 and the bolt 210 are arranged in series along the line of actuation so that, when the effector 222 extends from the housing 221, the effector 222 and the bolt 210 move forward together along the line of actuation until the bolt 210 is in the extended position. The effector 222 is coupled to the connecting end 213 of the bolt 210 by a pin joint 214. The pin joint 214 comprises a pin joint axis that extends in the z-direction. The pin joint 214 can therefore accommodate any misalignment of the actuator 220 and the bolt 210 within a manufacturing tolerance. In other words, the effector 222 does not have to be exactly parallel with the line of actuation because the pin joint 214 can accommodate the effector 222 extending at a small angle to the line of actuation without causing an excessive bending force on the effector 222. By accommodating a lateral movement of the effector 222 during extension of the effector 222, the manufacturing tolerances of the locking mechanism 200 can be increased without adversely affecting the longevity of the actuator 220. In the illustrated embodiment, the bolt 210 and the actuator are attached to a bed 270. The bed 270 takes the form of a plate to which components of the locking mechanism 200 may be attached by bolt, screw or other suitable means. To assemble the locking mechanism 200 to the vehicle 100, the bed 270 is attached directly 7 or indirectly to the vehicle body 300. In this way the locking mechanism 200 may be partially assembled separate to the vehicle body 300 for attachment to the vehicle body 300 at a later stage of vehicle assembly. It will be appreciated that in other examples which are not illustrated, the bolt 210 and the actuator 220 may instead be individually attached to the vehicle body 300. In one example, the bed 270 is configured for attachment to a vehicle frame of the vehicle body 300. A guide block 290 is attached to the bed 270 to guide the bolt 210 as it moves between the extended and retracted positions. The guide block 290 takes the form of a body that is attached to the bed by a screw, bolt or other suitable fixing. Alternatively, the guide block 290 may be integrally formed with the bed 270. The guide block 290 comprises an aperture 291 in which the bolt 210 is received. The aperture 291 in the guide block 290 is hereinafter referred to as the ‘guide aperture 291’ to distinguish it from the aperture 311 in the vehicle body 300. As the bolt 210 moves between the extended and retracted positions, the bolt 210 slides through the guide aperture 291 for communication with the aperture 311 in the vehicle body 300. The guide aperture 291 corresponds in size and shape to the constant cross section of the bolt 210 so that substantially no gap exists between the bolt 210 and an inner surface 29T of the guide aperture 291. In this way, the position of the bolt 210 is precisely located as it moves between the extended and retracted positions for precise alignment with the channel 284 in the strike plate 280. By ‘substantially no gap’ it is meant that the gap is less than 0.5mm or less than 0.25 mm. The inner surface 291’ of the guide aperture 291 slides directly against the bolt 210 during movement of the bolt 210. The guide aperture 291 may therefore be lined with a material appropriate for forming a plain bearing. Alternatively, the body of the guide block 290 is wholly formed from a material suitable for forming a plain bearing so that the bolt 210 may slide directly against the body. The locking mechanism further comprises a safety release mechanism 230. The safety release mechanism 230 is configured to allow the door 101 to be opened in the event the actuator 220 fails. The safety release mechanism 230 comprises a release catch 231 and a spring 232. When the bolt 210 is in the extended position, opening the release catch 231 frees the spring 232 to move the bolt 210 in a rearward direction along the line of actuation so that the bolt 210 moves away from the extended position. In this way, should the actuator 220 fail with the bolt 210 in the extended position, the release catch 231 may be opened to withdraw the bolt 210 from the channel 284 of the strike plate 280 and allow the door 101 to be opened. In the illustrated embodiment the spring 232 is a tension spring 232 that is attached at one end to an anchor 250 point and at the other to the connecting end 213 of the bolt 210. The anchor point 250 is a boss that upstands from the bed 270 and is attached thereto by a screw, bolt or other suitable fixing to retain the anchor point 250 at a fixed location of the locking mechanism 200. With the bolt 210 in the retracted position, the anchor point 250 is spaced from the connecting end 213 of the bolt 210 to allow the tension spring 232 to sit in between. Movement of the bolt 210 into the extended position tensions the tension spring 232 to provide a force on the bolt 210 that acts in rearward direction. Therefore, the spring 232 is in a tensioned state when the bolt 210 is in the extended position so that the spring 232 may provide the necessary force to withdraw the bolt 210 from the extended position. The release catch 231 comprises a bracket 233. The bracket 233 is a structure that upstands from the bed 270 and is attached thereto by a screw, bolt or other suitable fixing to retain the bracket 233 at a fixed location 8 of the locking mechanism 200. The actuator housing 221 is attached to the bracket 233 prior to opening of the release catch 231. In this way, the actuator housing 221 is retained in a fixed location of the locking mechanism 200 by the bracket 233 prior to opening of the release catch 231 without the need for further actuator fixings. The bracket 233 therefore needs to be sufficiently stiff to react the force of the actuator 220 as the bolt 210 is moved between the retracted and extended positions. When the release catch 231 is open, the actuator 220 is no longer fixed relative to the bed 270 of the locking mechanism 200. In this way both the actuator 220 and the bolt 210 together form part of a displaceable assembly. In the event the release catch 231 is opened and the bolt 210 is in the extended position, the tension in the spring 232 drives the bolt 210 and actuator 220 simultaneously rearward along the line of actuation. This simultaneous displacement of the bolt 210 and the actuator 220 simplifies the construction of the locking mechanism 200 by allowing the bolt 210 to be withdrawn in the event of actuator failure without the need to separately move the actuator 220. The bracket 233 is spaced in the y-direction from the line of actuation so that the bracket 233 does not obstruct the rearward movement of the bolt 210 and the actuator 220. The release catch further 231 comprises a pin 234. Prior to opening of the release catch 231, the pin 234 is received through the bracket 233 to fixedly secure the actuator housing 221 to the bracket 233. In the illustrated embodiment, the bracket 233 comprises two lugs 235, 235’ spaced apart in the z-direction. Each lug 235, 235’ comprises a through hole. A coupling element 236 fits between the lugs 235, 235’ for attachment thereto by the pin 234. The coupling element 236 has a through hole which aligns with the through holes in the lugs 235, 235’ for receipt of the pin 234 to secure the coupling element 236 to the bracket 233. The coupling element 236 comprises two lugs 237,237’ spaced apart in the z-direction. To distinguish the lugs 237, 237’ of the coupling element 236 from the lugs 235, 235’ of the bracket 233, the lugs 237, 237’ of the coupling element 236 are hereinafter referred to as coupling lugs 237, 237’. A boss 223 extends from a rear facing surface of the actuator housing 221 between the coupling lugs 237, 237’. Each coupling lug 237, 237’ comprises a through hole. The boss 223 comprises a through hole which aligns with the through holes in the coupling lugs 237, 237’ for receipt of a coupling pin to secure the actuator housing 221 to the coupling element 236. The coupling element 236 comprises a surface 238 that abuts a corresponding surface 239 of the bracket 233 when the coupling element 236 is secured to the bracket 233 by the pin 234. The surfaces 238, 239 abut each other either side the axis of the pin in the x-direction. In this way, during movement of the effector 222, the resulting force in the x-direction is resolved by the abutting surfaces 238,239 to prevent rotation of the coupling element 236 around the pin 234. The coupling element 236 therefore serves as a cantilever beam that bridges the gap between the bracket 233 and the actuator housing 221 and provides the required spacing in the y-direction of the bracket 233 from the line of actuation. To open the release catch 231, the pin 234 is removed from the bracket 233 to free the coupling element 236 for displacement in a rearward direction with the actuator 220 and the bolt 210 along the line of actuation. In the illustrated embodiment, the actuator 220 and bolt 210 are simply secured to the bracket 233 by the pin 234. This means that releasing the release catch 231 is a mechanically simple operation that can be effected by only the movement of the pin 234 in a single direction (the z-direction). Alternatively, a further linkage may be provided to remove the pin 234 if direct access to the pin 234 is not possible. It will also be apparent that the release catch 231 can take other forms that will be apparent to the skilled person and that the actuator housing 221 may be attached to the bracket 233 by means other than the pin 234. It will also be appreciated that in other unillustrated embodiments the coupling element 236 may be omitted and the actuator housing 221 connected to the bracket 233 in some other way. For example, the actuator housing 221 could comprise a lug extending from a lateral face of the housing 221 to engage the lugs 235, 235’ of the bracket 233. In the illustrated embodiment, a cable 239 is attached to the pin 234. The cable 239 is routed through a cable guide 240 of the bracket 233 so that the cable 239 passes directly down (in the z-direction) to the pin 234. From the position shown in figure 2, a tension applied to the cable 239 pulls the pin 234 directly up in the z-direction to remove the pin 234 from the bracket 233. In this way, the release catch 231 can be opened without direct access to the pin 234. Indeed, by using a cable 239, the cable 239 may be routed to any part of the vehicle 100 where access to the release mechanism 230 is required. The safety release mechanism 230 may be accessible from either the exterior or interior of the vehicle 100. The locking mechanism 200 further comprises a hard stop 260 to limit the rearward movement of the bolt 210. The hard stop 260 is a boss-like structure that upstands from the bed 270 and is attached thereto by a screw, bolt or other suitable fixing to retain the hard stop 260 at a fixed location of the locking mechanism 200. The hard stop 260 is configured to abut a flange 215 of the bolt 210 when the bolt 210 is in the retracted position. The hard stop 260 comprises a threaded through hole 261 to receive a screw 262. The screw 262 is configured to provide a surface to abut the flange 215 of the bolt 210 in the retracted position. The axis of the threaded through hole 261 is parallel to the x-direction so that the screw 262 may serve as an adjuster to adjust the location along the x-direction that the bolt 210 abuts the hard stop 260 in the retracted position. In this way, the withdrawal of the bolt 210 under the force of the spring is controlled. The ultimate distance that the spring may move the bolt 210 is limited to the retracted position, allowing the locking mechanism 200 to be more easily reset. It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

1. A door locking mechanism for a vehicle, the locking mechanism comprising:a bolt having a free end and a connecting end;5 an actuator coupled to the connecting end of the bolt and arranged to move the bolt in a lineardirection between an extended position and a retracted position; anda strike plate having a channel in which the free end of the bolt is receivable, wherein the channel extends in a first direction and comprises an entrance section and an interior section, the entrance section comprising an internal surface inclined at an oblique angle to the first direction so that the entrance section10 narrows from an opening to the entrance section to the interior section, and wherein the interior section has a constant cross section along the first direction,wherein the bolt and actuator are configured for attachment to a body of the vehicle and the strike plate is configured for attachment to a door of the vehicle so that, when the bolt is in the extended position, the free end of the bolt is received in the channel of the strike plate to lock the door to the vehicle body.

152. The mechanism of claim 1, wherein the bolt comprises a constant cross section along a portion of the length of the bolt, wherein the bolt moves a distance equal to or less than the portion of the length of the bolt as the bolt moves between the extended and retracted positions.

3. The mechanism of claim 2, wherein the free end of the bolt comprises a canted surface having a leading edge and a trailing edge;J wherein the leading edge defines an edge of the canted surface furthest from the connecting end ofthe bolt, and the trailing edge defines an edge of the canted surface relatively closer to the connecting end of CQ the bolt than the leading edge; andwherein the portion of the length of the bolt comprising the constant cross section extends between the trailing edge and the connecting end; and, optionally,wherein the canted surface is a contoured surface.

4. The mechanism of any preceding claim, wherein the actuator is a linear actuator and comprises an 30 actuator housing and an effector that extends from the housing to effect movement of the bolt between the extended and retracted positions.

5. The mechanism of claim 4, wherein the effector is coupled to the connecting end of the bolt by a pin joint.

356. The mechanism of any preceding claim further comprising a guide block, the guide block having an aperture in which the bolt is received to guide the bolt as it moves between the extended and retracted positions.40 7. The mechanism of any preceding claim comprising a bed to which the bolt and actuator are fixable;and wherein the bed is configured for attachment to the vehicle body.

8. A vehicle sub-assembly comprising the mechanism of any of claims 1 to 7, wherein the sub-assembly further comprises at least part of the vehicle body comprising a door surround, the door surround comprising an aperture from which the bolt extends during movement between the retracted and extended positions.5 9. The sub-assembly of claim 8 when dependent on claim 2, wherein the aperture corresponds in sizeand shape to the constant cross section of the bolt so that substantially no gap exists between the bolt and an inner edge of the aperture.

10. The sub-assembly of claim 9, wherein substantially no gap is a gap of less than 1 mm, or less than 10 0.5 mm, or less than 0.25 mm.

11. The sub-assembly of any of claims 8 to 10 further comprising a door configured to overlap the door surround when the door is in a closed position, wherein the strike plate is positioned in the door to align the channel of the strike plate with the aperture of the door surround when the door is in the closed position.1512. The sub-assembly of claim 11 when dependent on claim 3, wherein, when the door is in the closed position, the free end of the bolt is arranged to engage the internal surface of the channel as the bolt moves into the extended position; and wherein engagement of the free end of the bolt with the internal surface of the channel draws the door toward a vehicle centreline to compress a door seal.

13. The sub assembly of any of claims 8 to 12, wherein, when the bolt is in the retracted position, the free end of the bolt is flush with an external surface of the door surround.14.A vehicle comprising the sub assembly of any of claims 8 to 13.

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