Eaton Corporation

Ronald R Tremonti

Sherif S Gindy

A constant bending moment device (70) for strain gauge measurement of a force (F) upon an object (32) by means of bending moment. Device (70) is provided with a base member (30) that is adapted to engage object (32) and has a pair of spaced-apart column members (34, 36) extending away from the side of base member (30) facing away from object (32). Column members (34, 36) have respective substantially parallel neutral axis (38, 40) and respective moment arms (37, 39) that extend generally orthogonally towards each other in overhanging relationship to base member (30) and merge at a common portion (24) therebetween having a loading axis (46) that is substantially parallel to neutral axis (38, 40) and equidistant therebetween. Portion (24) is adapted to receive and direct force (F) along loading axis (46) preferably by including an undercut (45) therein and columns (37, 39) have respective substantially equivalent constant cross-sectional configurations along the respective lengths thereof between base member ( 30) and moment arms (37, 39) such that force (F) imposes a substantially constant bending moment along said lengths enabling greater freedom in the location of one or more strain gauges therealong as well as eliminating moment gradients across the strain gauges.

Constant bending moment device for strain gauge transducers

A load plate is rigidly supported by a central pedestal strain gaged for bending about a central axis. In one embodiment, the pedestal is mounted to the center of a yoke bar supported by two legs strain gaged for comprehensive loads only the sum of which is indicative of the magnitude of the plate load. The legs are supported by base webs strain gaged for bending about a central axis orthogonal to the axis of pedestal bending. The output of the bending strain gages enables determination of the coordinates of the load location on the plate from the central axis axes. In a second embodiment, the pedestal is supported by a block rigidly attached to the end of a cantilevered member extending at right angles from the pedestal. The cantilever member is strain gaged at two longitudinal stations for reading the differential of the bending strain to thereby determine the shear loading, or plate tactile load. One of the coordinates of the applied load on the plate is determined from the output of the pedestal bending strain gages and the other coordinate from one of these bending strain gage sets on the cantilever member. An optional bellow over the cantilever member provides in reared torsional stiffness without decreasing bending sensitivity.

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Troy, MI, United States of America

Ronald R Tremonti