GB449754A - Improvements in or relating to motor road repair or tower wagons - Google Patents

Abstract

449,754. Portable platform elevators. WOODHEAD, R., and WOOD HYDRAULIC HOIST CO., Ltd., 30A, Union Street, Southport, Lancashire. Dec. 28, 1934, No. 37118. [Class 78 (iii)] [See also Group X] The type of apparatus in which a hydraulically-extended telescopic tower mounted on a wheeled vehicle and carrying a slueing platform at its upper end is modified by providing (1) means operable from the platform for slueing the latter and fixing it in any desired angular position, (2) a pump with distributing valves operated from the platform for manipulating the tower, (3) means for connecting adjacent sections of the tower in a watertight manner, and for cushioning the movement of the telescoping parts at the limit of extension. Fig. 1 shows the wheeled vehicle 1 carrying the telescopic standard 3, 4, 5 and the upper platform 6. A pump of the gear wheel type, driven by the motor on the vehicle, draws liquid through a pipe 11, Fig. 4, from a tank and delivers it past the non-return valve 12 and hand-controlled plug valve 13 to the delivery pipe 7a leading to the telescopic tubes. A screw-adjusted ball-valve 24 returns excess liquid to the supply tank through the pipe 25 at a set predetermined pressure. The valve 13 can be set to three positions as follows (1) as illustrated, for extending tower, with ports 14 and 15 in communication and 16 closed, (2) maintaining the tower in an elevated position with port 15 closed and 14 and 16 forming a direct communication between opposite sides of the pump, (3) for lowering the tower, with port 14 closed and 15 and 16 in communication. The valve is operated by a crank arm 22, Fig. 5, connected by a link 22 to a system of telescoping rods and tubes 17, 19, terminating at the upper end in a socket 23 below the platform. A ring of holes on the rotating platform permits the insertion of a turning key into the socket 23 in any angular position of the platform, thus operating the valve from the platform. To rotate the platform 6, 44 a spring-controlled pawl 49, Fig. 2, is withdrawn from a notch 48 in the standard by depressing the member 52 with the foot. The hand wheel 56, Fig. 1, can then be operated to rotate the platform by toothod gearing 58, 59, the sleeve or cap 45, Fig. 2, moving angularly round the top of the tube 5 during the process. The piston 28, Fig. 6, at the bottom of each section is bolted, and preferably also keyed, to a member 30 welded into the end of the tube. It is prevented from turning by guide-bars 33 screwed to the walls of the casing 3. Fig. 8 shows spring plungers 42 which engage the upper side of the piston at the bottom of tube 4 and cushion further movement when the tubes are nearing maximum extension. The member 36, carrying the plungers, is positioned by a spacing ring 39 and screwdown ring 40, which also forms the base of a packing gland 41 tightened by the screwdown collar 3<a>.