A motor vehicle locking system

Abstract: A cable drive assembly 102 for a motor vehicle locking system is described. A lock mechanism 104 is mounted on a first carrier 108. The first carrier is connected to a second carrier 110 by a cable, such that turning of an appropriate key in the lock causes the first carrier to rotate. In turn this causes the second carrier to rotate. Rotation of the second carrier causes a latch mechanism remote from the locking system to be actuated. The first carrier prior is held in a first position within a housing prior to insertion of the lock mechanism. Insertion of the lock mechanism during assembly of the locking system frees the carrier and allows it to rotate in response to turning of the lock mechanism.

Description: The present invention relates to a locking system for a motor vehicle, and in particular to a cable drive assembly for a motor vehicle locking system. The cable drive assembly allows a motor vehicle door lock to be located at a position remote from a motor vehicle door latch mechanism. Known locking systems for motor vehicles can be complex to manufacture and difficult to assemble. In particular, there is a difficulty in maintaining a lock mechanism in a desired correct relationship with an associated housing and drive mechanism during assembly. There is scope for failure of the locking system in all of these areas. It is an advantage of the present invention that it provides for ease of assembly and manufacture. It also allows for the motor vehicle door lock to be positioned at a location remote from the motor vehicle door latch mechanism. EP-A-0375275 discloses a door latch having a cable link between a door handle and a latch mechanism. According to a first aspect of the present invention, a cable drive assembly for a motor vehicle locking system comprises a housing, a first pulley mounted within the housing, a second pulley mounted within the housing and cable means, characterised in that the cable means is secured at first and second ends to the second pulley and at an intermediate point to the first pulley. Preferably the first pulley is held in a first position within the housing prior to insertion of a lock mechanism and is mounted in a second position for rotation within the housing when the lock mechanism has been inserted. More preferably, the housing and the first pulley are provided with complementary locating features to hold the first pulley in the first position. Preferably, the second pulley is mounted for rotation within the housing. Preferably the cable means comprises a cable connected at a first end to the second pulley, at an intermediate point to the first pulley and at a second end to the second pulley. Preferably, the housing is provided with a flange to prevent interference with the cable means. Preferably, the housing is provided with a cover to prevent interference with the cable means. According to a second aspect of the present invention, a locking mechanism for a motor vehicle comprises a lock mechanism, a cable drive assembly according to the first aspect of the invention, drive means and a latch mechanism. The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows an exploded perspective view of a part of a cable drive assembly in accordance with the present invention; Figure 2 shows a side view of a cable drive base housing included in the part shown in Fig. 1; Figure 3 shows a plan view of the cable drive base housing shown in Fig. 2; Figure 4 shows an opposite side view of the cable drive base housing shown in Fig 2; Figure 5 shows a sectional view along line V-V of Fig. 3; Figure 6 shows an end view of the cable drive base housing shown in Fig. 2; Figure 7 shows a plan view of a drive pulley included in the cable drive base housing shown in Fig. 1; Figure 8 shows a sectional view along line VIII-VIII of the drive pulley shown in Fig 7; Figure 9 shows a plan view from above of driven pulley included in the cable drive base housing shown in Figure 1; Figure 10 shows a plan view from below of the driven pulley shown in Figure 9; and Figure 11 shows in section a door assembly incorporating a cable drive assembly according to the present invention. Referring to Figures 1 to 10 of the drawings, a cable drive assembly 2 for a motor vehicle locking system is shown. The cable drive assembly includes a housing. The housing comprises a base 4 and a cover 6. The cable drive assembly further comprises a first carrier means mounted within the housing, a second carrier means mounted within the housing, and a cable means in the form of a cable assembly 8 connecting the first and second carrier means. The cable drive base 4 comprises a substantially elongate member 10 having rounded portions at first and second ends thereof, and a first wall 12 extending in a first direction normally thereto around the periphery of the elongate member. A substantially circular opening 14 is provided at the first end of the elongate member. Three dogs 16,18,20 are provided disposed about a periphery of the opening 14 extending in the first direction. A second wall 22 around the opening extends in a second direction away from the first end of the elongate member. A flange member 23 extends from the elongate member to the circular wall to increase the structural strength of the base. The elongate member is further provided with two pairs of guide means 24,26 and a pair of guide rails 28 within a region of the elongate member bounded by the first wall. Each of the guide means comprise a pair of oppositely disposed resilient members 27 defining a gap therebetween. Each guide rail 28 takes the from of an upstanding member. A rotatable axle 30 is mounted at the second end of the elongate member, again within the region bounded by the first wall. The rotatable axle is conveniently "X" shaped in plan view and includes a circular flange 31 at a lower end thereof. An outer surface of the first wall is provided with a plurality of protrusions 32 extending flexibly away from an outer surface of the first wall. The first carrier means conveniently comprises a drive pulley 34. The drive pulley is substantially circular and is provided with a "V" shaped groove 36 running around a periphery of the pulley and a single recess 38 is formed at the periphery of the drive pulley extending through a thickness of the pulley. The drive pulley further comprises an upper surface 40 and a lower surface 42. The upper surface is provided with a boss 44. The lower surface is provided with a pair of shaped recesses 46,48 to receive in use engagement means of a locking mechanism, three recesses 50,52,54 disposed about the periphery of the lower surface and a central recess 56 shaped to receive a portion of the locking mechanism which in use will function as an axis of rotation for the drive pulley 34. The three recesses are conveniently equally spaced about the periphery of the lower surface and are adapted to engage with the dogs 16,18,20 provided about the circular opening in the base housing. The central recess is conveniently stepped in section and circular in plan view. The second carrier means conveniently comprises a driven pulley 58. The driven pulley is substantially circular and is provided with a "V" shaped groove running around a periphery of the pulley. A pair of recesses 66,68 are formed at a periphery of the driven pulley and extend therethrough. The driven pulley further comprises an upper surface 60 and a lower surface 62. The upper surface is provided with an upstanding circular wall 64. Within the upstanding wall are located engagement means 70. In use, the engagement means engage complementary features of a drive means. The lower surface is provided with a shaped recess 72 to engage the rotatable axle provided at the second end of the elongate member. The driven pulley fits over and is supported by the rotatable axle. The cable assembly 8 comprises a length of cable 74 having first and second ends. At the first and second ends of the cable there are provided respective first and second barrel shaped engagement features 76,78. The engagement features are secured to the respective end of the cable by any suitable means. A further barrel shaped engagement feature 80 is secured to an intermediate portion of the cable. A first sheath 82 is provided on the cable between the first end of the cable and the intermediate portion of the cable. A second sheath 84 is provided on the cable between the second end of the cable and the intermediate portion of the cable. The cable 74 may run freely within each of the first and second sheaths. The cable drive cover 6 comprises an elongate member 86 . A first end of the elongate member is provided with a sunken dimple 88. In use, a reverse side of the sunken dimple 88 is adapted to receive the boss 44 of the drive pulley. A second end of the elongate member is provided with an upstanding wall disposed about a generally circular opening 92 extending in a first direction from the elongate member. The elongate member further comprises an upstanding wall 94 extending in a second direction about a periphery of the elongate member. The wall is provided with a plurality of cut out portions 96. The cable drive assembly is used to form part of a locking system for a motor vehicle. The cable drive assembly may conveniently be assembled prior to use in the locking system. The further barrel shaped engagement feature 80 is located within the recess 38 in the drive pulley and each of the first and second barrel shaped engagement features 76,78 are located within a respective recess 66,68 provided in the driven pulley. The driven pulley is placed in position over the rotatable axis 30. The driven pulley 34 is placed over the circular opening such that the recesses 50,52,54 provided on the lower side of the drive pulley engage with the dogs 16,18,20 provided about the opening. The ends of the sheaths 82,84 are pressed into the guide means on either side of the base housing such that the sheaths pass between the upstanding wall of the base housing and the guide rail 28 on each side of the housing. The cable drive cover 6 can then be placed over the cable drive base housing 4 and pressed home such that the plurality of protrusions 32 provided on the base engage in the plurality of openings 96 provided in the cover. In this way the drive pulley is held in a first position within the housing prior to insertion of a lock mechanism. The lock mechanism is provided with protrusions that engage the shaped recesses 46,48 in the lower side of the drive pulley. Further insertion of the lock mechanism pushes the drive pulley off the dogs and thereby frees the carrier to allow the drive pulley to rotate. It can be seen that the housing and associated parts can be mounted into position in a door assembly, prior to insertion of the lock mechanism. Once the housing is in position, the lock mechanism can only be received in the housing in the correct position, i.e. when the protrusions on the lock mechanism engage with the shaped recesses 46,48 provided on the first carrier means. Thus there is no difficulty in maintaining the lock mechanism and the housing in the correct relationship during assembly as has been the case in the past. Referring to Figure 11, there is shown a motor vehicle door assembly 100 incorporating a cable drive assembly 102 according to the present invention. A lock mechanism 104 is shown retained in position in an outer panel 106 of the door assembly. The lock mechanism has pushed the drive pulley 108 from the dogs such that in response to turning of the lock, upon insertion and rotation of an appropriate key, the drive pulley is rotated by protrusions provided at one end of the lock mechanism engaging with shaped recesses provided on the lower side of the drive pulley. The cable assembly (not shown) transfers rotation of the drive pulley 108 to the driven pulley 110. A latch mechanism 112 is provided to secure the motor vehicle door assembly in a closed position in a motor vehicle. The driven pulley 110 is connected to the latch mechanism 112 by drive means. In the illustrated embodiment, the drive means is in the form of a paddle 114.

Claims: A cable drive assembly for a motor vehicle locking system comprising a housing (4,6), a first pulley (34;108) mounted within the housing (4,6), a second pulley (58;110) mounted within the housing (4,6) and cable means (8), characterised in that the cable means (8) is secured at first and second ends (76,78) to the second pulley (58;110) and at an intermediate point (80) to the first pulley (34;108). A cable drive assembly according to claim 1, characterised in that the first pulley (34) is held in a first position within the housing (4,6) prior to insertion of a lock mechanism (104) and is mounted in a second position for rotation within the housing (4,6) when the lock mechanism (104) has been inserted. A cable drive assembly according to claim 2, characterised in that the housing (4,6) and the first pulley (34) are provided with complementary locating features (16,18,20;50,52,54) to hold the first pulley (34) in the first position. A cable drive assembly according to any previous claim, characterised in that the second pulley (58) is mounted for rotation within the housing (4,6). A cable drive assembly according to any previous claim, characterised in that the housing (4,6) is provided with a flange (12) to prevent interference with the cable means (8). A cable drive assembly according to any previous claim, characterised in that the housing (4,6) is provided with a cover (6) to prevent interference with the cable means (8). A locking mechanism for a motor vehicle charactered in that it comprises a lock mechanism (104), a cable drive assembly (2;102) according to any previous claim, drive means (114) and a latch mechanism (112).

Inventors: TYAS BARRY, TYAS, BARRY
Applicants: MG ROVER GROUP LTD, MG ROVER GROUP LIMITED
Application year: 1999
Main classification: E05B65
IPC codes: E05B65, E05B17, E05B53