| 摘要 |
1,219,297. Measuring angles. PRECITRONIC GES FUR FEINMECHANIK UND ELECTRONIC G. m.b. H. Nov. 12, 1968 [Nov. 22, 1967], No. 53513/68. Heading G1X. A transducer for an angle-of-attack indicator for an aircraft comprises a drag responsive sensing vane 1 carried by a shaft 3 so that it adjusts itself in accordance with the wind direction, the shaft being supported by two radial gas bearings 7, 8 and an axial gas bearing 9 all externally pressurized, clamping of the movement of the shaft being effected by iron cores 21 with electrical coils 22 generating eddy currents in a bell-shaped member 20 on the shaft 3, the current in the coils 22 being varied in accordance with the speed of the aircraft. The gas bearings are fed through a connection 4 and the gas exhausts through bores 12, 13, 14 leading to the intension of the shaft 3 and then through a labyrinth 17 to the outside, the labyrinth providing a seal against dirt and moisture. In an alternative embodiment a spring-loaded diaphragm seal may be provided, this being held open by the gas pressure of the bearing and serving to seal the bearing in shutting off of the pressure. The aircraft speed is sensed by a Pilot tube (not shown) connected to a differential pressure device which serves to adjust a potentiometer connected through an amplifier to the coils 22, whereby the eddy currents produced in the member 20 are a function of aircraft speed. In this way the indicator can be used at all air speeds even supersonic speeds. The angular position of the shaft 3 is sensed by a co-operating rotor 24 and stator 25 of a synchro-mechanism. |
