GB609816A - Improvements in an apparatus for measuring compression forces, more particularly a weighing apparatus - Google Patents

Abstract

609,816. Pressure indicating. COX & STEVENS AIRCRAFT CORPORATION. June 22, 1945, No. 15945. Convention date, June 10, 1944. [Class 40 (i)] [Also in Group XXXVI] Pressure applied to a member 21, Fig. 3, compresses a plurality of pillars 22a ... 22d mounted on a base 20 to vary the resistance of strain gauges 30a, 30b, &c. attached to the pillars. A pillar 50, not in contact with member 21, may carry similar gauges to allow correction for temperature variations. The gauges are preferably connected in a bridge, Fig. 11, whose out-of-balance potential is an indication of the applied pressure. A resistance 80, Fig. 11, may have a temperature coefficient to compensate changes in the modulus of elasticity of the pillars due to temperature change. A further resistance 83 or 83<SP>1</SP> may be added to compensate for unequal effects on the resistance gauges of temperature changes. The member 21 may have an enlarged base, Figs. 5 and 7 (not shown). The gauges may be in the form of wire embracing the pillar, Fig. 7 (not shown), thus utilising the Poisson effect, and in this case the pillar may have a decreasing diameter towards the centre, Fig. 15 (see Group XXXVI). Both types of gauge may be utilised with pillars of appropriate length, Fig. 5 (not shown). Specifications 549,140 and 565,462, [Group XXXVI], are referred to.