Force sensing

Claim 1

A plural load axis force and torque transducer for simultaneously measuring loads along at least one force load axis and at least one moment load axis, comprising a first rigid member, a second rigid member, one or more flexural beams connected between said first rigid member and said second rigid member, said first and second members and said beams having a center point, said flexural beams having, for each said load axis, respective decoupling points that are symmetrical with respect to the center point, each said flexural beam having a length, a major lateral axis and a minor lateral axis, said major and minor lateral axes being of different sizes, said flexural beams having, for each said load axis, symmetrical strain fields located on said flexural beams such that first and second strain fields achieve strain responses to a load of a single axis of magnitude equal to each other and third and fourth strain fields achieve strain responses to said load of said single axis of magnitude equal to each other, two of said responses being of one sign and two being of the other sign, said symmetrical strain fields also having responses to loads of at least three other axes, for each said load axis, the strain responses of said strain fields to loads of all other axes being capable of being cancelled out when the responses of one of said first and second fields and one of said third and fourth fields are given opposite sign and the responses are added together, strain gauges placed at said first, second, third and fourth strain fields for each said load axis, and a bridge circuit for each said axis in which said strain gauges are electrically connected to be additive with respect to the load of said single axis and neutral with respect to loads of all other axes, said bridge circuit providing an output that indicates load of said single axis and is decoupled with respect to loads of all other axes.