GB1444906A - Hydraulic transmitter - Google Patents

Abstract

1444906 Valves STERLING HYDRAULICS Ltd 15 Aug 1973 [30 Aug 1972 6 Nov 1972] 40255/72 and 51066/72 Heading F2V [Also in Division F1] The transmitting unit of an hydraulic telemotor system comprises a housing 10 slidably mounting a piston 60 having a bore 61 containing a relief valve 67 for excess pressure in transmitting line 36, there being means for replacing movement of the transmitter with the receiver at a preselected point in the stroke of piston 60. As shown, the rephasing means comprises a further piston 63 slidable within bore 61 and having a rod 64 whose end 65 is attached to a valve closure member 73 biased by spring 74 against 0-ring 71 carried by relief valve 67. A pin 76 carried by piston 60 passes through elongated slot 75 in piston 63 to determine the limits of travel of the latter relative to piston 60. To effect rephasing, a manual control lever attached to a shaft (14, Figs. 2, 4, not shown) is rotated causing piston 60 to be moved via a pinion (15) and rack 17 into a position, e.g. mid-stroke, in which piston end 63A engages stop 51 thus unseating closure member 73 from 0-ring 71. Axial grooves in rod end 65 and a transverse bore 77 in piston 60 thus permit transmitting line 36 to communicate with a liquid reservoir. Rephasing may take place at any other preselected position by appropriate choice of the length of piston 63. E.g. if the latter ends at dotted line 78, then rephasing would occur at the end of stroke of piston 60. The receiver may be spring biased towards its central position. There may be two pistons 60 mounted in a common housing 10 and having racks 17 engaging opposite sides of a common pinion (15). Fig. 6 (not shown) illustrates a slightly modified transmitter. Numerous applications are specified.