Patent GB-630064-A (GB)
Title: Improvements relating to remote control systems
IPC: F15B9/12
Filed: 1943-07-15
Abstract: 630,064. Aircraft gun mountings. SPERRY GYROSCOPE CO., Inc. July 15, 1943, No. 11567. Convention date, Dec. 27, 1941. [Classes 92 (i) and 92 (ii)] [Also in Group XXIX] In a system for.controlling the motion of a body (i.e. the guns and turret in an aircraft) in two dimensions, the boundary of the area in which the body can move is defined by a stop device comprising two terminal members capable of abutting against one another and each connected through gearing interposed in the main control system to a subsidiary control member, and the relative displacement which can take place between each terminal member and its associated subsidiary control member will cause movement of the control member only when the two terminal members abut against each other. In an embodiment, signals to alter the elevation of the guns are received from a remote sighting station and applied to an actuator 343, Fig. 3B, which rotates a valve 347, Fig. 4, to connect pressurefluid and exhaust through pipes 372, 373 to the sides of a piston 376. Movement of the latter actuates a variable capacity pump 142 of a hydraulic transmission unit to vary the speed of the output motor 144, the latter moving the guns 131, Fig. 2, through bevelled pinions 157, shaft 155, pinion and quadrant 161 and shaft 163. Valve 347 includes a follow-up sleeve 379 which is rotated to centralize the valve from the output end of the hydraulic transmission unit through a worm 543, gear 545, differential 539, gears 549, 553, 555, 559, and a gear 561 connected to the sleeve. A decaying movement proportional to gun speed is also imparted to the sleeve from piston 376 through a link 519 crank 521, dashpot 525, crank 533, and gear 537 which acts on differential 539. When first actuated, the piston and cylinder of the dashpot move solid, but the piston is leaky and is brought back to a central position by springs 529. An indication of the position of the guns is given through gears 555, 563 on to an insulated rotary gear 357. When the relative displacement between the remote sight and the guns exceeds the range of the transmitter 343, a " coarse signal " transmitter 345 moves an arm 351 into contact with strips 353 on the gear 357 to make the circuit of one side or the other of an electromagnet 359. The armature 365 of the magnet will move to one pole or the other and a further valve 369 will be reciprocated into one of its two extreme positions. In these positions, the valve 347 is isolated and the full pressure of the fluid supply is applied to the piston 376 to move the guns at maximum speed. Movement of the armature 365 also operates a switch 368 to open the circuit of the fire control to prevent the guns firing when they are greatly out of correspondence with the sight. The pressure-fluid operating the system is made pulsating at high frequency to break the static oil film friction in the valves, and the connections 372, 373 may be periodically reversed at a high rate to supply " dither" and avoid instability. Signals to alter the turret in azimuth are applied through similar apparatus to a second hydraulic unit 145, the output shaft 149 of the latter rotating the turret through pinions 127, 125 of which the latter " runs round " a gear-ring 126 fixed to the aircraft. The movement of the output end of unit 142, 144 is applied through worm 543, gears 545, 599, 601, 603, 607, 609, 613, differential 615, gears 619, and pinion and rack 581, to a follower 571 which moves between cam surfaces 573, 575, carried on a rotatable cylinder 341. In a similar manner, the movement in azimuth of the turret rotates the cylinder 341 through gears 577, 579, so that the area between the surfaces 573, 575 simulates the permissible zones of movement of the guns. When the element 571 abuts against one of the surfaces 573, 575, certain elements of differential 615 will become fixed in position and any further movement tending to drive the element 571 on to the surface 573 or 575 will be transmitted through differential 597, gears 623, 627, and lever 633, to a further valve 371 which, when actuated, throttles the supply of pressure oil to piston 376 to slow up the guns and, in extreme cases, reverses the connections to pipes 372, 373 to-stop the guns or even reverse them. Specification 630,092 [Group XXIX], is referred to. The Specification as open to inspection under Sect. 91, comprises also a simplified form of valve 347 and an alternative to dashpot 525 comprising a valve 185, Fig. 6 (Cancelled), and a piston motor 215 connected as shown between the rod 519 of piston 376 and the shaft 535 carrying gear 537. When piston 376 moves rod 519, floating lever 173 first pivots about the point 221 by which it is fixed to piston 215 and this turns a lever 177 about its shaft 535 which is thus rotated and the movement is communicated through differential 539 to the follow-up sleeve 379. The movement of lever 177 also actuates piston valve 185 controlling the connection of pressure and exhaust pipes 197, 195, respectively, to the motor 215 which is actuated to move lever 173 about its point of connection 171 with rod 519. This pivoting movement of lever 173 will raise lever 177 to its original position to give a recentring movement to valve 185 and to follow-up sleeve 379. The decay in the component thus communicated to follow-up sleeve 379 may be lengthened by throttling the ducts 208, 210 connecting valve 185 and motor 215 or the ducts may provide throughways only intermittently by means of a continuouslyrotating valve 212. This subject-matter does not appear in the Specification as accepted.