GB945759A - Improvements in or relating to apparatus for lifting and lowering loads - Google Patents

Abstract

945,759. Lift trucks; counter-balancing. GEO. W. KING Ltd. July 20, 1962 [July 20, 1961], No. 26325/61. Headings B8B and B8H. A mast assembly extending below an overhead trolley (not shown) comprises a section 10 supported by the trolley, a second section 11, slidable vertically on the section 10 and connected to a counterweight 14, which is heavier than the section 11, by cables 12 passing over a pulley 13 mounted on the section 10 or on the trolley, and load supporting platform or forks 15 which are slidably supported on the section 11. Cables 16 secured to the load support 15 pass over power driven pulleys 17 mounted on the mast section 10 or on the trolley and are secured to the bottom of a container 18 mounted on the counterweight 14. In operation, starting from the position shown, the pulleys 17 are rotated to raise the load support 15, and as the load support rises, the counterweight 14 raises the mast section 11. Any slack produced in the cables 16 after the mast section 11 has reached its upper limit of travel is accommodated in the container 18. In lowering the load support from its uppermost position, the load support is lowered on the mast section 11 until the cables 16 become taut, whereupon further lowering of the load support causes the cables 16 to raise the counterweight thereby allowing the mast section 11 to fall. In an alternative embodiment (not shown), the mast assembly extends upwardly from a mobile carriage.