GB1086042A - Fluid pressure actuable jacks - Google Patents

Abstract

1,086,042. Hydraulic jacks; hauling cables. " SOTECO," SOCIETE TECHNIQUE CONTINENTALE. Feb. 15, 1965 [Feb. 15, 1964], No. 6487/65. Headings B8B and B8J. A traction and lifting device comprises a jack with a cylinder 1 in which is a piston 5 fixed to the end of a tubular rod 7 traversed coaxially by a fixed tube 10. The device is anchored to a fixed point by lugs 50 1 , 50 2 and a traction cable of a load (not shown) is passed through the tube 10, a mobile jaw 38 attached to the rod 7 and a stationary jaw 51 adjacent the lugs 50 1 , 50 2 , the jaws 38, 51 being held open for this purpose by pusher members 53. When the jack is fed with fluid under pressure on its rod side the rod 7 retracts, clamps 40 1 , 40 2 of the mobile jaw 38 being tightened on the cable by a spring 45 and by the resisting force of the cable. The cable is drawn to the left and slides between clamps 40 1 , 40 2 of the stationary jaw 51, causing it to open. The pressure fluid is supplied from a reservoir 15 by a pump operated by a handle 29. The reservoir 15 has a suction tube 16 on its centre line, it is more than half full when the rod 7 is fully extended so that as the effective cross-section of the piston 5 is greater on the left than the right the layer of air imprisoned in the reservoir 15 is compressed as the rod 7 is retracted. This provides a source of energy to extend the rod 7 after a complete retraction stroke when a discharge valve (32), Fig. 3 (not shown), is opened through a knob 37. Fig. 5 (not shown) illustrates an embodiment with an external source of pressure fluid. When the load is motorized, so that the movement of the cable is from left to right the' jack must supply a braking effort which is made possible by use of the pusher members 53 to loosen and tighten the clamps of the jaws 38, 51. Fig. 6 (not shown) illustrates an embodiment having a distributer (75) with three extreme positions. Manual control of members (84), (85) makes possible a controlled positive advancing movement, and also a controlled withdrawal movement of the cable and of the load (by acting on the pusher members 53 as previously described). In a further embodiment (not shown) the jaws 38, 51 are reversed and the pressure fluid is supplied to the left side of the piston 5 so that the positive direction is left to. right.