Patent GB-995544-A (GB)
Title: Fluid pressure servo motor control systems
Inventor: GOEG PAL
IPC: F15B21/08
Filed: 1962-02-22
Abstract: 995, 544. Fluid-pressure servomotor systems. GANZ-MAIAG MOZDONY-VAGON-ES GEPGYAR. Feb. 22, 1962, No. 6999/62. Heading G3P. Four electromagnets I-IV with adjustable strokes are connected by links 1, 2, 4, to a rod 3 so that by selective energization of the electromagnets the rod may occupy any one of sixteen positions; the links 1,2,4, and strokes may be arranged so that the distance between each of the sixteen positions may be different. The rod 3 is attached by a nut 13 to a floating lever 5 having three hinge points A, B, C, connected, respectively, to a cylinder 6, the rod 3 and a control valve 7 loaded by a spring 14. Upward displacement of the point B by the rod 3 causes the lever 5 to pivot about point A thereby moving the valve 7 to supply fluid pressure to one side of a vane 15, the otherside thereof being exhausted via an adjustable throttle 16; the vane 15 turns in the direction of the arrow and through a cam 18 secured thereto allows the cylinder 6 and hence the point A to move upwards under the action of the spring 14 whereby lever 5 pivots about the point B and the valve 7 is closed; concomitantly the vane 15 is stopped in a new position corresponding to one of the selected positions of the rod 3. Movement of the rod 3 in the opposite direction reverses the vane, the first or starting position of which is adjustable by a screw 8 which displaces the nut 13 and point B. Rotation of the vane is transmitted to a shaft 32 by gearing. Should the fluid pressure in the cylinder 6 fall below a value at which it is in equilibrium with the spring 14 then the latter translates the valve 7 and cylinder 6, and the vane 15 is rotated counterclockwise to an outer-stop position; a plunger 17 in the cylinder is faced inwardly by the cam 18, the displaced fluid flowing to the supply via a throttle 22. The shaft 32 is connected to the fuel regulator of a vehicle engine and in the outer stop position of the vane the engine is shut off. The oil in cylinder 6 is obtained from the engine lubricating system and when the pressure in the latter is insufficient to overcome a spring 29 a ball closure 28 is unseated so opening an outlet from the cylinder 6 which is of larger area than that of the throttle 22 so that the plunger 17 is forced inwardly as described above. The same action is effected upon energizing an electromagnet V and opening a valve 27 against a spring 26. The cylinder 6 is also connected to a pressure switch 34, 35 by a plunger 36 so that the engine cannot be started until the lubricant pressure below the plunger 36 is at the value necessary to extent the plunger 17. The engine may also be stopped by pulling an arm 33, which, through a cable and an arm 24, actuates the valve 7 and rotates the vane to the outer-stop position; the lever 5 pivots about point B and the point A lifts so that the fluid is forced out of the cylinder 6. If the point A moves slowly the fluid is expelled through the throttle 22; should the point A lift rapidly the fluid pressure rises sufficiently to open the valve 27 and enable the fluid to escape therethrough. The throttle 16, which determines the speed of clockwise vane movement and hence of vehicle acceleration, is inoperative when the vane is rotated counter-clockwise; the extent of throttling and thus the clockwise vane speed can be set in eight steps. The apparatus is applicable to gear mechanisms, instead of fuel control.