Improvements in or relating to Power Actuated Wave-Guide Switches

1,171,923. Waveguide switches. MARCONI INSTRUMENTS Ltd. 23 May, 1967 [10 Aug., 1966], No. 35889/66. Heading H1W. The rotor of a waveguide switch is actuated by an electric motor through a reduction gearing and an inverse self-locking Geneva mechanism. As described, the actuating mechanism is applied to a known kind of switch comprising an internal rotor having two passages which connect in pairs four radial waveguide ports in an external stator, a rotation of 90 degrees serving to commute the connected ports. The rotor is mounted on the same axis as the driven plate 12 of a Geneva mechanism, the driving member of which consists of an arm 10 rotating about a shaft 11. The arm 10 carries a roller 9 which engages in turn each of the four grooves 13 in the driven plate whereby a 360 degrees rotation of the arm produces a 90 degrees rotation of the plate. The switch is constructed so that connections are made when the roller 9 is in the central space 14 between one groove 13 and the next and the locking arc 20 is engaged with one of the locking sectors 19 of the plate. A cam 15, driven by the electric motor at half the speed of the arm 10, actuates a switch 16 whenever the arm reaches such a switching position, the effect of the switch 16 being to open a power circuit and to close a short circuit connected in parallel to the terminals of the motor 6. Thus the rotor is brought rapidly to rest in the switching position. A further switch 7 reverses the effect of the switch 16 and re-starts the motor.