GB966123A - Improvements in or relating to industrial trucks - Google Patents

Abstract

966,123. Masted lift trucks. LANSING BAGNALL Ltd. May 29, 1963 [May 7, 1962], No. 17551/62. Heading B8H. In a fork lift truck mast assembly comprising three sections, extension of an hydraulic ram 42 connected between the intermediate section 20, 21 and the inner section 27, 28 raises the inner section with respect to the intermediate section and simultaneously raises the intermediate section with respect to the fixed outer section 15, 16 by means of chains 39 which each pass from an anchorage at the top of the outer section, round pulleys 37, 38 mounted at the lower end of the intermediate section to an anchorage at the top of the inner section. The ram 42 is a two-stage ram and comprises a cylinder 57, provided with pulleys 66 and slidably mounted on a cylinder 47 which is secured at its upper end to an upper cross-member 29 of the inner mast section and which contains a tubular piston 43 secured at its lower end to the base of the fixed outer mast section. Chains 67 pass from anchorages on a cross-member 30 of the inner mast section, round the pulleys 66 to anchorages on the lifting carriage 34 which is slidable on the inner mast section. The arrangement is such that on applying fluid pressure to the bottom of the tubular piston 43, the cylinder 57 is raised on the cylinder 47, thereby raising the lifting carriage 34 on the inner mast section, until stops on the two cylinders abut, in which position the carriage 34 is at the top of the inner mast section. Further supply of fluid then raises the cylinder 47 on the piston 43 thereby raising the inner mast section with respect to the intermediate mast section and raising the inner and intermediate mast sections with respect to the fixed mast section.