GB1071894A - Improvements relating to lift trucks - Google Patents

Abstract

1,071,894. Mast assemblies for lift trucks. CLARK EQUIPMENT CO. May 12, 1965 [May 18, 1964], No. 19955/65. Heading B8H. A triple-section mast assembly for a lift truck includes a pair of chains 150 which extend between anchorages on the fixed mast section 38 and on a bracket (140), Fig. 8 (not shown), on a section 110 of a telescopic ram assembly (90) and pass over sprockets 152 mounted on a cross brace 60 at the lower end of the intermediate mast section 44, and chains 146 which extend between the lifting carriage 51 and the bracket (140) and pass over sprockets (124), Fig. 7 (not shown), on a crosshead at the top of the ram section 120. The chains 146, 150 and sprockets (124), 152 are arranged in perpendicular vertical planes to improve visibility through the mast assembly, Figs. 1, 2 (not shown). The hydraulic ram assembly (90) comprises an inner tubular member (92), Fig. 8 (not shown), secured at its lower end (94) to a cross brace on the fixed mast section 38 and serving as a rigid conduit for pressure fluid. An inner structural tubular member (100) is secured at its lower end to the lower end of the intermediate mast section 44 and an integral tubular member (108, 110) encompasses the tubular member (100). Nested within the annular space between the members (108, 110) there is an intermediate tubular ram (120). In operation, on extending the ram assembly, the chains 146 elevate the lifting carriage 51 to the Fig. 4 (not shown) position as the ram (120) moves upwardly along the member 108. Continued supply of pressure fluid causes extension of the mast assembly, Fig. 5, to the Fig. 6 (not shown) position.