SELF-ALIGNING MOTION DETECTORS

摘要

A motion detector for energizing an alarm signal at a suitable location and which is responsive to linear motion of an object on which the detector may be mounted and capable of self-alignment to the object. The detector comprises a case or suitable enclosure within which an outer pendulum or pendulum body is supported for freedom of universal but sluggish movement and within which a second pendulum or body is supported for universal and unconstrained movement with respect to the outer pendulum. Contact is made between respective pendulums or bodies upon motion of the case to transmit an electrical signal to a suitable sensor, alarm or the like. The motion of the outer pendulum is suitably constrained as by immersing it in a liquid within the case or by providing it with a greater period than the inner pendulum or body in compound pendulum aspects. A contact ring may be located on the inner wall of the outer pendulum or other suitable contact means for electrical contact between the ring and the inner pendulum or between the contact means to close a control circuit.