GB207934A - Improvements in or relating to the control of hydraulic steering gear pumps - Google Patents

Abstract

207,934. Hastie & Co., Ltd., J., and Riddell, W. G. Oct. 4, 1922. Regulating delivery by closing suction and delivery valves. - Steering gears for ships of the type where electrically-driven pumps actuate hydraulic rams are provided with a hydraulic relay system above the pump valves and in which is an automaticallyclosable valve whereby the pump valves close on rise of pressure due to closing the relay valve, the latter being actuated by hand or by a solenoid in circuit with the electric motor. Electric motors drive pumps 10, 11, Fig. 1, which are connected by mains 12, 13 with the ram cylinders 14, 15. The valves 19, 20 of the pump 10 and valves 21, 22 of the pump 11 have their chests connected by pipes with relay valves 28 forming part of relay systems 30, 31 which communicate with a common tank. Each pump valve is of the construction as shown in Fig. 2, the stem 33 having a control spring 35 and the head having a cylindrical enlarged extension 40 which slides freely in a bore communicating with the relay valve 28. The passage 39 is coupled to the pump and the passage 38 leads to the mains to the cylinders 14, 15. The relay valve 28 has a closure spring and a solenoid 43 in circuit with the motor leads whereby the valve is held open when the motor is switched on. When the valve 28 is open the pump is able to operate the steering gear, since the liquid pressure is able to raise the valve 19 and establish communication between the passages 38, 39. Leakage past the extension 40 escapes freely through the open valve 28. When the driving current fails or is cut off, the valve 28 closes and the accumulated leakage above the portion 40 reaches a pressure sufficient to close the valve 19 and cut the pump off from the hydraulic mains. Specification 21932/09, [Class 114, Ships &c., Propelling &c.], is referred to.