Patent GB-1045154-A (GB)
Title: Vehicle lift structure
IPC: B66F7/02
Filed: 1963-08-20
Abstract: 1,045,154. Garage lifts; screw-and-nut lifting jacks. C. H. BROWN, I. VON KERT HOTT, and W. E. WEBSTER. Aug. 20, 1963, No. 32821/63. Headings B8H and B8J. A vehicle-lifting device comprises vehicle supports 50 slidably mounted on a beam 46 secured to arms 44 on a lifting carriage 40 which is movable along a mast 12 by means of a screw shaft 24 which is suspended from a bearing 26 at the top of the mast and which is driven by an electric motor 38 through reduction gearing and an electromagnetic brake. The motor 38, reduction gearing and the brake are supported on a plate 20 at the base of the mast and are detachably coupled to the screw shaft so as to be capable of being removed without removing the screw shaft 24 or the lifting carriage 40. The screw shaft engages a nut, Fig. 11 (not shown), rotatably mounted on a cross-member 42 of the lifting carriage and serving as a housing for ball-bearings which are guided on the screw threads. The mast 12 is supported by rollers 144 and by castors 146 which are mounted on forwardly-extending legs 140 and which are urged downwardly by springs mounted in housings 148. Stabilizing legs 152 are pivoted to the legs 140 and are adapted to be folded into the broken-line position, Fig. 1, when not in use. " Up " and " down " circuits for energizing the motor 38 are provided and may be closed by a manual selector switch 60a on the side of a circuit control box 60 or by a remote control switch connected by a lead 132, Fig. 9, to the control box 60. As shown in Fig. 9, a pair of remote control switches in a single housing, Fig. 10 (not shown), control a pair of lifting devices when used to raise a vehicle. The upward and downward movement of the carriage 40 is limited by a limit switch mounted in a housing 63 on the control box 60. The switch arm is pivotally mounted on the housing and extends between a pair of plates which are interconnected by a cam and secured to a square-section rod 66 rotatably mounted between the base plate 20 and an upper crossmember 22 of the mast 12. The rod is also capable of limited vertical movement against the action of a spring 72. In operation, two feelers mounted on a bracket 88 on the carriage surround the control rod 66 and are adapted to engage respectively an abutment secured adjacent the top of the control rod 66 to raise the switch arm and break the " up " motor circuit and the lower switch-actuating plate to lower the rod 66 and the switch arm to break the " down " motor circuit. To lock the carriage 40 to the mast 12, a lock bar, Fig. 7 (not shown), is slidably mounted on one of the arms 44 and is Spring-urged into apertures 100, 100a provided In a side member of the mast. The locking device is coupled through a lost-motion device to the control rod 66 so as to rotate the rod as the lock bar moves into one of the apertures, thereby causing the cam surface "connecting the switch-actuating plates to actuate the switch arm. The lifting device may be releasably clamped to an elongate, hollow box member having a longitudinal slot in its upper surface and forming a track embedded in the floor by one or more clamping devices, each comprising an inverted T-shaped member slidably mounted on the base of the lifting device and urged upwardly by a spring, the head of the T-shaped member being adapted to engage within the box member.