GB724511A - Improvements in and relating to lifting appliances - Google Patents

Abstract

724,511. Garage lifts; safety catch gear; fluid-pressure lifting-apparatus. BRADBURY & SONS, Ltd., J., and POWELL, V. Nov. 2, 1951 [Nov. 15, 1950], No. 27980/50. Classes 78 (2) and 78 (3). In a garage lift the platform structure 9, 24 is raised by a single hydraulic ram operatively engaging one corner of the structure directly, and operatively connected with the other corners by means of cables. As shown in Figs. 1, 2, the ram comprises a cylinder 3 which is slidable on a member 2 and has trunnions 6 which engage notched arms 7 secured to one member 9, the other corners of the structure being guided by the engagement of rollers 36 thereon with slots 30 in posts 4, but in a modification (not shown) sleeves secured to the platform structure are guided on stationary rods. Three cables 11 which are each anchored at one end at 12, pass over pulleys 13, 14 and then over the appropriate pulleys 16, 18, 21, 26, 28 to anchors 31 at the tops of the posts, the arrangement being such that these cables ensure that the corners of the structure move synchronously when the ram is operated. The lift is provided with catch gear and guiding means as described in Specification 724,512 and apparatus for cutting out the motor 35, which drives the hydraulic pump 34, when a hoisting cable breaks as described in Specification 724,513. A device for opening a limit switch 51 in the circuit of motor 35 if the predetermined lifting movement is exceeded is shown in Fig. 5 and comprises a rod 52 which rests operatively on the switch 51 during normal operation of the lift but which is raised to allow the switch to open when an abutment 55 on the rod engages the portion 56 of a slotted tube 57 secured to the cylinder 3. Fig. 6 shows a device for locking the corners of the platform, which comprises pillars 57, one of which is mounted adjacent each corner of the platform, box members 61, which are secured to the platform structure and each have guide holes 62, 63 slidable on pillars 57, and a ring 58 adapted to slide freely on the pillar when in the position shown dotted but which can be moved into the full-line position, where it bites into the pillar, by manual operation of a spring toggle mechanism 60a. Specification 651,650 and French Specification 833,872 also are referred to.