GB403098A - Method of measuring the relative displacement of two or more points of a body - Google Patents

Abstract

403,098. Linear-dimension gauges; dynamometers. LINCKH, H. E., 30, Merscheidstrasse, and KLUGE, J., 28, Englischestrasse, both in Charlottenburg, Berlin. May 9, 1932, No. 13302. Convention date, May 8, 1931. [Class 106 (ii).] Comprises a method of measuring length characterized in that the changes of length influence an elastic device through the medium of a pressure responsive measuring device and that the power of resistance of this elastic device itself is measured by the reaction of this power on to the pressure responsive device. The expansion chamber shown in Fig. 1 comprises a diaphragm M<2> clamped to a frame G and having a central ball by which pressure may be transmitted to a pressure plate D and in turn to quartz crystals Q on either side of an electrode E. The quartz is supported on a second diaphragm M<1> the stiffness of which may be changed by using interchangeable reinforcing rings R. The electrode is connected to a valve voltmeter. In Fig. 2 the device is used to measure the lateral movement of a shaft in its bearings. The shaft W bears against a lever H fulcrumed about a knife edge and the pressure exerted by by the shaft is transmitted through the lever H to an expansion chamber M containing piezoelectric crystals as in Fig. 1. In a third form for measuring large forces the force is applied to a structure and the forces due to the deformation of the structure only are transmitted to the expansion chamber. To avoid effects due to heat two pairs of quartz elements of opposite polarity are used, the force being measured independently of the conditions of heating.