GB1051509A - - Google Patents

Abstract

1,051,509. Hydraulic jacks. INTERNATIONAL BUSINESS MACHINES CORPORATION. Oct. 19, 1965 [Nov. 13, 1964], No. 44134/65. Heading B8J. [Also in Division F1] A cylinder body 10 is divided by a partition 62 into first and second cylinder spaces 18, 20 in which are located pistons 14, 16 having tubular rods 36, 40 with apertures 39, 41 therein and extending through cylinder end caps 90, 92 and the rod 36 is secured to a fixed reference member 34 and is supplied from a line 38 with constant pressure fluid which passes through aperture 39, and through a duct 30 connecting the rod ends of cylinder spaces 18, 20; the inner ends of these spaces being connected through flexible hoses 46, 48 and three-way valves 59, 56 either to exhaust or the constant pressure duct 38 whereby according to the setting of valves 54, 56 the cylinder body 10 together with piston 16 may effect a stroke relative to the fixed piston 14 or the piston 16 may move relative to the cylinder body 10. With valves 54, 56 connected to exhaust the pistons 14, 16 abut axial projections 66, 68 of partition 62 and the body 10 assumes the retracted position. On connecting valve 54 to line 38 body 10 together with piston 16 is moved to the right and on connecting valve 56 to line 38 piston 16 is moved to the right relative to body 10. The tubular rod 40 passes through the end cap 94 of a further cylinder body 12 of similar construction to body 10 including three-way valves 58, 60, pistons 22, 24 and a rod 42 which is connected to a load 44 which may be moved in steps or in multiples thereof up to fifteen by virtue of the effective stroke lengths at cylinder spaces 18, 20, 26 and 28 increasing in the ratio 1, 2, 4 and 8. In operation and assuming duct 38 to be pressurized and valves 54, 56, 58, 60 connected to reservoir 51, opening of valve 54 to pressurize cylinder space between the piston 14 and partition 62 results in movement of the cylinder body 10 together with connected pistons 16, 22, 24, cylinder body 12 and the load 44 one step to the right. Opening of valve 56 to pressurize the cylinder space on the L.H.S. of piston 16 results in movement of piston 16 relative to body 10 together with displacement of piston 22, body 12, piston 24 and load 44 an extra two steps to the right. Similarly opening at valve 58 results in movement of cylinder body 12, piston 24, rod 42 and load 44 a further four steps whilst opening at valve 60 produces a movement of the load a further eight steps making fifteen in all.