GB228166A - Improvements in or relating to systems and apparatus for electric distant-control or signalling - Google Patents

Abstract

228,166. Baule, M. E. A. Jan. 21, 1924, [Convention date]. Magnetic compasses. - Relates to compasses employed in an electric distant-control or signalling system of the type in which the needle carries a conducting part moving in an insulated circular channel containing a liquid of low conductivity such as water. In the application to a liquid-filled compass, Fig. 4, the compass card 13, mounted on a pivot 15 in a receptacle 14 filled with a liquid of low conductivity, carries a terminal 16 connected by a wire to the pivot 15 and balanced by a counterweight 17. The terminal 16, is curved about the pivot 15 as centre, and moves within an annular insulating. vessel 27. The under side of the glass top 30 of the receptacle 14 is made convex to enable the bubbles due to the electrolysis to accumulate at its edge and escape through a tube 31. The lost liquid is replaced from a reservoir 29. In a modification the circuit connection to the pivot 15 is made through a rod extending through the top of the receptacle 14 to provide a counter-pivot with a drop of mercury to ensure good contact at the pivot. Stationary conductors 21 in the controlling or signalling circuit, and unconnected conductors 41 disposed between these to direct the flow of current through the liquid, are similarly curved about the pivot 15 as centre, and may be adjustable for correcting compass variations due to the ship's head. In the application to a dry compass the liquid is contained in a deep annular trough disposed around the compass bowl. Course -recording apparatus, e.g. such as described in Specification 145,708, may be controlled by a more powerful motor 52, Fig. 8, brought into action in opposite directions by deviations of the repeating index 40, at the dis. tant station. For this purpose the index carries a brush 47 movable over two nearly semi-circular conducting segments 48, 48<1> in an insulated disc 49 adapted to be rotated by the electric motor 52, the circuit connections being such that the motor rotates in one direction or the other according as the brush is on one or the other segment.