GB396343A - Improvements in and relating to shock absorbing or damping devices for hydraulic steering gears - Google Patents

Abstract

396,343. Ships' steering gear. DEUTSCHE WERFT AKT.-GES., Postfach, 889, Hamburg, Germany. April 18, 1933, No. 11286. Convention date, April 28, 1932. [Class 114.] In hydraulic steering- gear in which shocks caused by blows from the sea on the rudder blade are absorbed the shock-absorbing means comprises a balancing device normally held in central position by spring means and connected in parallel with the fluid pressure system such device being displaceable to absorb shocks in such a manner that the quantity of pressure fluid on each side of the system remains constant. As shown in Fig. 1, a balancing or shock-absorbing device, which is connected in parallel with the operating cylinders c, c<1> and pistons b, b<1> of the rudder, comprises cylinders g, g<1> and a piston d controlled by springs f, f<1>. External shock on the rudder sets up a pressure in one or other of the cylinders c, c<1> which pressure forces the piston d against one or other of the springs f, f<1> to absorb th shock. In other arrangements the springs f, f<1> may be arranged externally and the cylinders g, g<1> may be movable with the piston or pistons stationary. Fig. 5 shows the device employing one spring f only, a reduced part r of the piston passing through loose discs s, t and the spring f. The discs s, tare apertured so that pressure is uniform throughout the cylinder g ; excess of pressure in that cylinder forces the piston d out of the cylinder against a compression of the spring f. Fig. 6 shows hollow pistons h, h<1> connected together by bars k and adapted to operate the rudder through the springs f, f<1>. Shock on the rudder forces one or other of the pistons b, b<1> into the hollow piston against spring pressure, the interior of the hollow pistons being in communication with the atmosphere through grooves m, m<1>.