Patent GB-971009-A (GB)
Title: Hydraulic actuating device for slide valves
IPC: F16K31/12
Filed: 1962-04-10
Abstract: 971,009. Valves. VEREINIGTE ARMATUREN G.m.b.H. April 10, 1962 [April 11, 1961; Oct. 17, 1961], No. 13836/62. Heading F2V. [Also in Divisions F1 and G3] An hydraulic actuating device for a slide valve in a tanker comprises an hydraulic rotary motor 1, Fig. 1, and a device for switching off the motor when a predetermined setting of the slide valve is reached, sealed as a selfcontained unit in a fluidtight casing 5 which is filled with oil and from which extends a driving stub shaft 4 of the motor for connection to the slide valve spindle and connections 8 for the pipes 10, 11 of the motor. The motor is mounted on a baseplate 2 from which projects a gear-wheel 3 and the driving stub shaft 4. A further shaft 6 extends upwardly from the motor and has a handle 7 for manual operation outside the casing 5. A gear train 19, 20 connects the shaft 6 to a threaded shaft 18 carrying a non-rotatable nut 21 which co-operates with valves 12, 13 in the pipes 10, 15 and 11,16 leading from the motor 1 and the connections 8 joined to the supply pipes 9, the nut operating the switches at the upper and lower extremes of its movement to slow and then stop the motor at positions corresponding to the open and closed positions of the slide valve. A reversing valve is provided in the supply pipes 9 to control the direction of rotation of the motor to open or close the valve. In order to adjust the operation of the valves 12, 13 to correspond with the settings of the slide valve, the nut 21 is formed in two parts, each part co-operating with a separate valve 12, 13 and having radial slots which engage a bar arranged parallel to the threaded shaft 18. The bar normally prevents rotation of the parts of the nut but can be disengaged from the slots to permit the parts of the nut to be rotated relative to the shaft and each other to positions which ensure that the valves will be operated at times corresponding to the settings of the slide valve, the bar then being re-engaged with the slots in the parts of the nut. The shaft 6 may also carry a nut 30 having an arm 31 engaging a slot 33 in a bell-crank lever 32, 42 mounted on a pivot 40. Axial movement of the nut 30 during rotation of the motor rocks the lever about the pivot to move a pointer 36 along a scale 38 to indicate the position of the slide valve. A remote indication may be provided by a telemotor having a transmitter 46 connected by a rod 44 to the lever 42, the transmitter having pipes 47, 48 leading to connections 49 for the pipes 50, 51 leading to a receiver. The transmitter 46 may consist of a pair of corrugated cylinders 63, 64, Fig. 2, connected to a similar pair of corrugated cylinders of the receiver 60 so that as one cylinder of one pair contracts, the connected cylinder expands to move an indicator 70 over a scale 71. Equalizing devices 72, 73 are provided to compensate for variations of volume of the fluid in the pipes and cylinders as a result of temperature changes. As shown in Fig. 2, check valves 54, 55 are provided in parallel with the valves 12, 13 so that these valves, when closed to prevent further operation of the motor in one direction, are by-passed to permit the motor to be operated in the opposite direction. A valve is provided in one of the pipes leading to the motor so that the pressure supplied to the motor is lower during a valve closing movement than during a valve opening movement. A plurality of actuating devices 150, Fig. 5, controlled by reversing valves 151 may be supplied with oil from a common source 250. Two pumps 251, 251b, driven by electric motors 252, 252b draw fluid through magnetic filters 256, 256b and discharge through check valves 258, 258b and shut-off valves 260, 260b to a common supply pipe 253, each pump having a pressure-relief valve 257, 257b and an indicator 259, 259b. Accumulators 270 are connected to the supply pipe 253 and a pressure-sensitive device 280 operates a switch 281 controlling the motors 252, 252b so that the pressure in the accumulators is maintained between predetermined upper and lower limits. A throttle valve 400 is connected between the supply and return pipes 253, 261 to reduce fluctuations of pressure in the pipe 253 and a reducing valve 420 and excess flow valve 300 are provided between the source 250 and pipes 200, 201 leading to the actuating devices.