GB685369A - Improved means for measuring angular velocities and displacements - Google Patents

Abstract

685,369. Turn-sensitive devices employing vibrating masses. VICKERS-ARMSTRONGS, Ltd., and JEFFREE, H. April 28, 1950 [April 29, 1949], No. 11538/49. Class 97 (iii). [Also in Group XXXVIII] An instrument for determining the angular displacement of, e.g., an aircraft, or its rate of pitch or yaw, comprises a reed 19 fixed at one end in compression against a piezocrystal in a housing 20 and supported between two diaphragms 13, 14, so that the free end, which is provided with mass balancing screws 191, may vibrate between three or more equi-angularly spaced electrodes 22-25, each of which is joined to a lead 26 for external connection. To detect roll, one pair of electrodes 22, 24 is charged to cause the reed 19 to vibrate in that plane, so that angular displacement of the instrument leaves the reed vibrating in the same plane in space, and signals are generated in the opposite pair of electrodes 23, 25, which may be detected and measured. To detect pitch or yaw, the free end of reed 19 is given a circular motion by a cyclic charge on the electrodes 22-25, so that a rotation about an axis perpendicular to the reed produces an end load on the piezo-electric crystal at 20, which can be measured. The electrodes 22-25 may alternatively be coils or piezo-electric crystals. Reference has been directed by the Comptroller to Specifications 601,051 and 611,021.