Patent GB-501503-A (GB)
Abstract: 501,503. Fluid - pressure servomotorcontrol systems. DEWANDRE, A. Aug. 25, 1938, No. 25003. [Class 135] [Also in Group XXI] Relates to aircraft or other vehicular mountings of the " ring " type, of the kind in which the manual training and elevating movements of the gun itself control the actuation of auxiliary motors for rotating the turret and raising the arched support on which the gun is mounted. According to the invention, the displacements of the gun about its axis control cams which actuate distributers for fluid admitted to the auxiliary motors, and the arrangement is such that the gun can be angularly displaced considerably beyond the positions necessary to' actuate the distributers, the turret and arched support then moving under the action of the auxiliary motors to a position corresponding to the orientation of the gun. In the construction shown, the arched support 13 is hinged at 14, Fig. 3, to the movable ring 15. The gun 6 is pivoted at 7, Fig. 1, to the forked end of a member 9 which is journalled in a casing 11 clamped to the arched support. The support 6a for the gun is fitted with cams 17, 18, which control the distributers associated with jacks 50a, 50b, Fig. 2, for raising the arched support, and the member 9 is formed with cams 60, 61 which control the distributers associated with means for rotating the ring 15. Upon elevating the gun about its pivot 7, the cam 17 first comes into operation by depressing a rod 19, the lower end of which bears against and depresses a plate 21 carried by a spring-controlled piston 22. A surface 26 on the piston is thus brought to bear against and move a rod 27 of a compressed air distributer 28 fixed to the casing 11. The rod actuates valves which establish communication between a compressed air source 59, Fig. 2, and a cylinder 58, the piston 57 of which is connected to the piston 55 of an oil-distributing system controlled by the cam 18. This cam comes into operation after the cam 17, and is adapted to move a rod 20 the lower end of which bears against an arm 39 secured to the rod 40 of a needle valve. An abutment 49 on a spring- controlled piston 48 bears on the underside of the lever. The valve rod is screw-threaded in an oil distributer 40 and thus, when rotated by the rod 20, moves axially away from its seat. Communication is thereby established between an oil cylinder 54, Fig. 2, and the hydraulic jacks, and the pistons 57, 55, now free to move, are urged by the compressed air to force oil into the jacks thus causing the arched support to rise. When the support reaches a position corresponding with the elevation of the gun, the rods 19, 20, are urged by the spring-controlled pistons into depressions in their respective cams and at the same time the valve 42 is moved against its seating while the valves of the air distributer are moved to the position in which the cylinder 58 is in communication with the atmosphere. When the gun is depressed about the pivot 7, the rod 19 is not actuated but the rod 20 is depressed to actuate the valve 42. The support then moves downwards under its own weight and oil from the jacks is forced into the cylinder 64 until.the support reaches a position corresponding with that of the gun. When the gun is trained about the member 9 the cams 60 or 61, according to training movement engage with their respective levers 62, 63, which are operatively, connected to a spring controlled piston 67. The piston moves in a fluid filled cylinder 68 which communicates with a similar cylinder 73 fitted with a spring-controlled piston 74. The rod 75 of the piston 74 is connected to a lever 76 adapted to move the valves of the distributers 78, 79, for compressed air and oil respectively. The rod 92 of the oil valve is fitted with a slotted plate 93, the slot of which is of such shape that an arm 96 of the lever 76 can move through a small angle in both directions from its normal position before it actuates the valve. In operation, the air distributer is first actuated when the gun is trained, and compressed air from the source 59 is supplied to one of the cylinders 97, 98, Figure 2, according to the direction in which the gun is trained. Further movement of the gun opens the needle valve of the oil distributer, thus establishing communication between two oil chambers 101, 102, formed respectively in the hollow pistons 99, 100 of the cylinders 97, 98. The pistons 99, 100 are thus freed to move under the action of the compressed air, and in moving rotate the circle with which they are connected by means of cables. Movement of the circle continues until it reaches a position corresponding with the direction in which the gun is trained.