Acceleration responsive device

Abstract

Abstract 816,779. Measuring acceleration electrically. GENERAL ELECTRIC CO. Sept. 29, 1955 [Oct. 4, 1954], No. 27752/55. Class 40 (1). [Also in Group XIX] In an acceleration responsive device comprising a container rotatably supported about an axis other than one passing through its centre of mass so that linear accelerations transverse to the plane containing the axis and centre of mass apply a torque to the container, and means for applying a counter torque in response thereto, the container is suspended in a liquid, the density of which is such that the upthrust thereof is equal to the weight of the container and its contents. In the embodiment the casing 10 incorporating an unbalance mass 15 is pivoted in bearing means 11 in a housing 12 fixed to the vehicle, the acceleration of which is to be measured. Angular displacement of the casing in response to accelerations normal to the plane of the drawing results in displacement of coil 21 in the air gap of the magnetic circuit 22, 23. The signal thus generated in the coil after amplification at 27 (Fig. 2) is applied to the control winding 16 of a two-phase motor, the rotor 17 of which together with flywheel 18 is freely pivoted in bearings 20. The motor energization is such that the reaction torque on the casing balances the accelerating torque to restore it to a null position. The torque on the rotor, which is therefore proportional to vehicle acceleration accelerates it proportionally so that at any instant rotor speed is proportional to vehicle speed, and, integrated angular displacement to distance travelled. The motor drives rotor 41 of a selsyn transmitter 42, the output of which, operates indicating or control mechanism. The wiring shown in Fig. 2 is omitted from Fig. 1 for clarity. Housing, 12 is filled with a low viscosity liquid, e.g.. heptacosafluorotributylamine of such density relative to the mass of casing 10 and its contents, and the distribution of mass in the casing is such that bearings 11 are unloaded except for acceleration along the rotation axis, when they provide a balancing torque.

Inventors

• 👤 Frithiof V Johnson

Bibliographic Details