Vehicle immobilization device

A vehicle immobilisation device comprising:

• a pair of chocks for abutting a vehicle wheel on either side of its ground contact point;
• a top hook for hooking over the wheel at a point over the ground contact point;
• a pair of chock arms for interconnecting the chocks, each said chock arm being secured to its one of said chocks, said chock arms being relatively movable to adjust the separation of said chocks;
• a stem interconnecting said top hook and said chock arms;
• locking means for locking said pair of chock arms and said top hook together in their respective positions whereby to captivate the vehicle wheel;
• and
• each said chock arm having:
• at least one engagement member for interengagement with said engagement member of the other of said chock arms at one of a plurality of relative positions corresponding to positions in which the said chock arms and said top hook are lockable;
• said engagement members being interengageable by relative movement towards each other in a direction normal to the direction of chock separation adjustment to prevent relative movement of said chock arms, and being disengageable by relative movement away from each other in the same direction to permit such relative movement;
• said stem being lockable to said chock arms with said engagement members interengaged, to prevent relative movement in the disengagement direction;
• said stem including two relatively longitudinally movable members, one connected to said top hook and the other adapted to be locked to said chock arms;
• one of said movable members having formations at spaced intervals;
• the other movable member having a key member for engagement with said formations;
• said key member in one position thereof allowing free longitudinal movement between said movable members and being rotatable to another position in which such longitudinal movement is prevented;
• and
• said key member having a spigot for effecting the rotation of said key member by lifting and twisting of said spigot, by screwing engagement with said stem, during engagement of said stem with said chock arms.

A vehicle immobilisation device comprising:

• a pair of chocks for abutting a vehicle weel on either saide (in a direction of rotation) of its ground contact point;
• a top hook for hooking over the wheel at a point over the ground contact point;
• a pair of chock arms for interconnecting the chocks, each said chock arm being secured to its one of said chocks, said chock arms being relatively movable to adjust the separation of said chocks;
• a stem interconnecting said top hook and said chock arms;
• locking means for locking said pair of chock arms and said top hook together in their respective positions whereby to captivate the vehicle wheel;
• and
• each said chock arm having:
• at least one engagement member for interengagement with said engagement member of the other of said chock arms at one of a plurality of relative positions corresponding to positions in which the said chock arms and said top hook are lockable;
• said engagement members being interengageable by relative movement towards each other in a direction normal to the direction of chock separation adjustment to prevent relative movement of said chock arms, and being disengageable by relative movement away from each other in the same direction to permit such relative movement;
• said stem being lockable to said chock arms, with said engagement members interengaged, to prevent relative movement in the disengagement direction;
• said stem including:
• two relatively longitudinally movable members, one connected to the top hook and the other adapted to be locked to the chock arms, the one of the movable members carrying a nut the other of the movable members being in the form of a screw thread engaging with the nut;
• and
• a key member lifted, during engagement of the stem with the chock arms, for engagement with the threaded member, whereby the longitudinally movable members are free to move longitudinally when the stem is disengaged and they are prevented from moving longitudinally when the stem is locked to the chock arms.

A vehicle immobilisation device comprising:

• a pair of chocks for abutting a vehicle wheel respectively in front and behind, in a direction of rotation its ground contact point;
• a top hook for hooking over the wheel at a point over the ground contact point;
• a pair of chock arms for interconnecting said chocks, each said chock arm being secured to its one of said chocks, said chock arms being relatively movable to adjust the separation of said chocks and adapted for interengagement at one of a plurality of relative positions;
• a stem for interconnecting said top hook and said chocks, said stem having:
• an upper portion connected to said top hook,
• a lower portion adapted to be fitted to said chock arms, said upper portion and said lower portion including respective longitudinally movable members, one of said movable members having a repetitive formation along its length, and
• key means accommodated on said lower stem portion for cooperating with said repetitive-formation movable member to substantially prevent longitudinal movement of said movable members--and separation of said portions--when said stem is fitted to said chock arms, said key means including:
• a displaceable member for actuating said key means displaceably mounted on said lower stem portion for displacement between a free position relatively further from said top hook when said stem is not fitted to said chock arms and an engaged position relatively nearer said top hook, in which said displaceable member engages one of said chock arms on fitting of said stem thereto, whereby such longitudinal movement is prevented;
• and
• said stem being adapted for interengagement downwards with said chock arms when interengaged for lifting said displaceable member;
• and
• locking means for locking said pair of chock arms together and to said stem on fitting of said stem, whereby to captivate said wheel within said two chocks and said top hook.