Miniature gimbal mounted magnetic field detectors

Abstract

A miniaturized electronic magnetic compass system, or the like, is mounted in a substantially cylindrical gimbal ring unit of about 0.75 in diameter, and 1.25 in length. Critical to the small size is the pendulum that positions the internal magnetic detector by gravity relative to the earth's surface. Thus, a pendulum formed of tungsten has its curved bottom surface formed of a central spherical surface and two flanking cylindrical surfaces meeting in two planes disposed at an angle intersecting with the pendulum axis of rotation. The mass of the detector is centered by resilient conductive spring plates bearing on gimbal pivot shafts, which also serve as electrical connectors for the detector. Thus, two separated shaft ends journalled in one gimbal ring, which is insulated to electrically isolate the shaft ends serve as two conductors. The gimbal system is damped in a perfluorocarbon oil. An outer cylindrical housing member removably envelops the gimbal system in a shock absorbing mount produced by rubber-like sealing members. an outer roll sensing coil is wrapped about a channel indented in opposite sides of the outer housing member. The housing members are grounded so that only one signal path is extended internally through the conductive spring plates.