Wheel-acting force measuring device

Abstract

A wheel-acting force measuring device permits accurate measurement of a shearing stress by removing a torsional stress component measured by a stress detector. A stress sensor includes four sensor segments which measure stress by a change in a characteristic thereof, arranged two on each of opposed surfaces of a base, preferably in cross form. The four sensor segments can be combined into various circuit configurations to produce a combined characteristic for each combination, each associated with a measurement of a particular stress acting on a wheel. In a preferred case, the four sensor segments are strain gauges, each which form part of a bridge circuit shiftably connected to allow the relative connection of each segment to be altered, thereby changing the configuration of the bridge. When in a first configuration, the output of the bridge circuit indicates primarily shearing strain mixed with a torsional strain component. When switched to a second switch position, the output of the bridge circuit indicates torsional stress. The torsional component may then be subtracted from the combined output measured when switched to the first position, yielding a value for the shear stress alone. The above may further be carried out using a logic bridge circuit arrangement to variably combine the segments. In a further embodiment, a plurality of stress sensors may be analyzed as above, the stress determined for each then extrapolated to yield a maximum value of shearing strain.

Dependencies are inferred from the claim text.