GB549028A - Earth inductor compass - Google Patents

Abstract

549,028. Earth inductor compasses. DUNCAN, W. O. (Intercontinental Service Corporation). July 5, 1941, No. 8522. [Class 37] An earth inductor compass comprises a con tinuously-driven motor' 1 m a screening housing 6, driving a shaft 3 carrying cruciform rods 4 on which are wound coils 5a ... d connected together in pairs and their ends connected to brushes 26a ... d fixed on the shaft 3. The brushes engage arcuate segments 14a ... d of a commutator, the segments 14a, 14c being connected at 18, 19 to rings 16, 17, respectively, to which a centre-zero indicating instrument is connected at 21, 22. The rings and segments are carried on insulating annuli 12, 13 on a wormwheel 11 which can be rotated by a worm 31 and flexible shaft 32 from a handle 33 with an associated indicator 34. In operation the handle 33 is adjusted to the desired course and so as to set the commutator with the line joining the mid points of segments 14a, 14c at right angles to the earth's field. In these conditions the reading of the instrument remains at zero, but any departure from the set course gives an indication, Figs. 4-9 (not shown). Means 30 is provided for constantly compensating for the earth field's vertical component, or the inductor mounted in gimbals and associated with a gyroscope.