Improvements in and relating to hand hydraulic steering gear for ships

摘要

851,362. Steering ships. DONKIN & CO. Ltd., PAULIN, W. S., and HALL, F. T. July 25, 1958 [May 22, 1957; Aug. 27, 1957], Nos. 16206/57 and 26946/57. Class 114. [Also in Group XXIX] A ship's hydraulic steering system comprises a hand operated reversible pump supplying liquid to one of two rams and a power operated pump with means sensitive to pressure variations caused by the hand pump and such that the power operated pump supplies liquid to the same ram as the hand pump. As shown in Figs. 1, 2 and 5 a hand pump 10 is connected by lines 12, 13 to a valve block 23 which is connected by lines 39, 40 to cylinders 14, 15 controlling the tiller 16. A power operated pump 24 is connected by a pressure line 24a and a return line 25a to the valve block. In order to steer to port, pump 10 is operated to supply liquid through line 13 to a chamber 30a where the pressure opens a non-return valve 26 and passes through ducts (not shown) to line 40 and ram 15. The pressure in chamber 30a also moves a shuttle 30 to the right to open a non-return valve 27 so that liquid from ram 14 can pass through line 39, by ducts (not shown) and valve 27 to line 12. Liquid from line 13 is also supplied through a duct 32 to a chamber 48 to move a valve 36 to the right, in which position the supply line 24a communicates through passages 36d in the valve and a duct 45 with a chamber 31a, whence the liquid passes through a non- return valve 28 to the ram 15. The pressure in chamber 31a moves a shuttle 31 which opens a valve 29 so that liquid from ram 14 can pass through the valve, a duct 46 and ducts 36e in the valve 36 to a chamber 36a whence it passes to the return side of pump 24. For steering the starboard the hand pump is operated to supply liquid through line 12. If it is desired to supply the steering rams solely from the power operated pump, the hand pump is actuated to produce a pressure sufficient to actuate valve 36 but insufficient to open valves 26, 27. When not steering the ram lines are closed by the valves 26-29, and valve 36 is centered by springs 34a, 35 and the supply from pump 24 passes through the passages 36d, 36e to both ends of chamber 36a and thence to the return line. In the modification of Figs. 11, 12 the power operated pump is a swash-plate pump 100 having the inclination of the swash-plate adjusted by a lever 104 normally biased by springs to a central position in which the delivery of the pump is zero. For steering to starboard a hand pump is actuated to supply liquid through a line 12 and duct 121 to move a piston 112 and lever 104 to the right so that pump 100 supplies liquid through a line 115 and non-return valve 109 to a ram line 39. The hand pump also supplies liquid through a valve 106 to the ram.