ENCLOSED MOMENT-INSENSITIVE LOAD CELL

摘要

A dual beam moment-insensitive load cell (10) is hermetically sealed in a bellows (15) or partial-bellows enclosure. The enclosure may have convolutions (20) over substantially its entire length which permits it to flex easily in the direction of load cell bending. The enclosure (15) is made resistant to elastic buckling under torsional forces produced by off-center loading of the load cell (10) by one or more rods (23) spaced circumferentially about the enclosure (15) and connecting together a number of the convolutions (20) after the convolutions are aligned. The alignment and torsional stiffening resist elastic buckling of the enclosure (15) and resulting error in the output of the load cell (10). Another form of enclosure has one or more convolutions at each end and joined by a relatively straight, non-convoluted wall which itself is resistant to torsional elastic buckling. The resistance of the wall to torsional elastic buckling can be increased by increasing its thickness uniformly or by applying stiffener rods thereto.