Patent GB-577002-A (GB)
Title: Improvements in electric remote control systems, suitable for the control of aerial bombs and other purposes
IPC: F41G9/02
Filed: 1940-05-02
Abstract: 577,002. Radio-controlled bombs. THOMSON, B. May 2, 1940, No. 7893. [Class 40 (i)] [Also in Group XXXIII] An aerial bomb in the form of a glider of which the control surfaces are adjustable by wireless signals from the launching aircraft is provided with port and starboard lamps of characteristic colours or flashed at a characteristic rate to enable its course to be observed at night. Adjusting control surfaces.-In one arrangement, Figs 2 and 7, a tail piece with vertical and horizontal surfaces 12, 11 is connected to the body of the bomb by a universal joint and is adjustable as a whole by screw jacks to give the effect of a rudder and an elevator. The forward end of the bomb is provided with vanes 45a ... 45c Àrotatable about pivot pins such as 52 and adjustable together by a common ring 65 to give lateral control. In a modification, Fig. 25, a fixed tail plane and fin are provided and control is by means of a rudder and a split elevator, the parts of which are moved in the same direction by a screw jack 35 or in opposite directions by a screw jack 59. The jacks are driven by motors such as 80, Fig. 13. Relays 132, 133, which receive rapidly recurring signal impulses of a duration characteristic of the extent of the desired movement, connect the motor in one or other direction to a main source of supply 131. As soon as the adjusting member moves out of the pormal position, brushes 90a, 90b which are normally resting in insulating gaps between high resistance coils 93b, 93c and a low resistance coil 93a wound on a drum carried by the nut portion of the jack, make contact with two of the coils and as a result a progressively increasing current in opposition to the operating current flows from source 100 during the intervals between impulses and tends to flow during impulses. A condition of equilibrium is ultimately reached and the jack remains in this position while impulses of the same duration continue to come in. When impulses cease, the motor restores the jack to normal under the influence of the reverse current. Signal transmitting and receiving arrangements.-A known type of short-wave transmitter comprising six transmitter valves 219, Fig. 19, and four modulator valves 223, is associated with a constantly running distributer 220 geared to a motor, the speed of which is kept constant by a synchronizer 280 receiving impulses from a multi-vibrator 221. The distributor comprises a fixed brush 231 which co-operates with projections 229 on a slip ring to give a synchronizing impulse every 120 degrees and three brushes such as 241 movable to make contact with different parts of triangular conducting segments 234, 234a or to rest in an insulating space between the segments. Each brush corresponds to a different control and is moved in one or other direction according as the adjustment is to be in one direction or the other and to an extent which, by determining the duration of the signal impulses, determines the extent of the adjustment. The brushes are adjusted by Bowden mechanism from an individual joystick and rudder-bar or from hand levers on the aeroplane control wheel or on a bomb-aimer's telescope. For example, there may be two levers, one of which has two movements at right angles. The distributer on making contact couples a valve 264 oscillating at a comparatively low but possibly supersonic frequency to the modulator. The transmitter thus sends up to three impulses of modulated carrier current per rotation of the distributer, the position of the impulses determining the nature of the control and their duration, its extent, and also three equally spaced synchronizing impulses. At the receiving end, all these impulses are repeated by a relay 192, Fig. 17, over a synchronous distributer 153 to the control circuits, Fig. 13 and the synchronizing device. Making bomb visible.-Lamps 203, 204 on the wing tips, silvered in front to reflect the light rearwardly, are differently coloured or are flashed at different rates by a commutator geared to the distributer. The lamp circuits are not completed until a predetermined time after the bomb has been launched. Synchronizing.-Before the release of the bomb, the transmitting and receiving distributers are coupled together mechanically in the right phase and run up to the proper speed. Thereafter, the speeds are kept constant and identical by a multivibrator 221 which delivers impulses to a synchronizer 280 coupled to the motor of the transmitting distributer and by synchronizing impulses sent three times per revolution and acting at the receiver on a known form of synchronizing device shown at 143 in Fig. 17. Launching gear.-The bomb is normally carried close to the underside of the fuselage by normal clips (not shown) beneath a member 335, Fig. 29, secured by limbs such as 337a, 337b having their upper ends rigidly secured to transverse spindles which are coupled together and to a shaft 345 carrying a snail 346 which is connected to the fuselage via an assembly of elastic loops 348. When a catch 351 is released, the bomb is released from the clips but is held by two electromagnets to the member 335 which is thus drawn down, with assistance from the elastic device to the position shown in dotted lines. The electro-magnets are then automatically de-energized, the member 335 is then moved by the elastic device to its normal position and the bomb falls off. Practice apparatus.-A dummy bomb has a pair of parachutes which remain in the nose while the bomb is falling but are drawn out by a pilot parachute 371, Fig. 31, covering the nose when it is manoeuvred so as to tail dive. When the parachute comes into action ballast is released.