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Month in the Patent Office: A Selection of the More Important Aircraft and Engine Specifications Published Recently

Aircraft Engineering and Aerospace Technology

ISSN: 0002-2667

Article publication date: 1 January 1932


For maintaining aeroplanes and other moving craft upon a set course a rudder is automatically given a series of impulses in one direction or the other whenever the craft moves off its course, a direction sensitive device, such as a magneto compass as described in Specification 342,038, [Group XXXVI], controlling the impulse machanism through electric discharge devices. The magneto compass comprises a winding 19 rotated by an air turbine 35 between the enlarged ends of two pole‐pieces 21, 22 pendulously suspended in a member 25 which can be set in azimuth by a worm and worm wheel operated from a knob 83. The pole‐pieces 21, 22 are adjusted so that they are at right‐angles to the earth's magnetic field when the craft is on its course and consequently no current is generated in the winding 19. A deviation in cither direction causes current collected from a commutator 36 to flow through a galvanometer winding 41 and move a finger 43 into contact with one or other of two studs 44, 45 connected through biasing batteries 60, 62 to the grids of two electric arc‐discharge tubes 12, 13 containing mercury vapour. Normally the grids are kept negative by batteries 59, 61 through resistances 63, 64. The plates 48, 51 of the discharge tubes are connected to solenoids 52, 57 in circuit with brushes 53, 58 rubbing on a disc 54 connected to a battery 56 for applying a positive voltage to the plates 48, 51. The disc 54, which has two insulated segments 70, 71, is continuously rotated by a motor 15 acting on a wheel 18 which has one or more cams 65, 66 adapted to engage cither of two followers 16, 17 when the appropriate solenoid 52 or 57 is energized. The followers 16, 17 are mounted on an arm 14 pivoted at 72 and connected to a rudder 14a so that as either follower is depressed the rudder receives impulses to one side or the other. No current flows through the tubes 12, 13 as long as their grids are negative but as soon as either grid is rendered positive by the closing of one of the contacts 44, 45 an are discharge is initiated and the corresponding follower 16, 17 is depressed into the path of the cams 65, 66. Alternatively the sole‐noids may act directly on armatures carried by the rudder lever, a continuously driven disc similar to the disc 54 being provided to render the action intermittent.


(1932), "Month in the Patent Office: A Selection of the More Important Aircraft and Engine Specifications Published Recently", Aircraft Engineering and Aerospace Technology, Vol. 4 No. 1, pp. 26-26.




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