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US 4,957,177 AGranted
Enclosed moment-insensitive load cell
AssigneeToledo Scale Corporation
InventorsMichael N. Hamilton, Edwin J. Stolz
Life of this patent
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AssigneeToledo Scale Corporation
InventorsMichael N. Hamilton, Edwin J. Stolz
Estimating the term…
A dual beam moment-insensitive load cell is hermetically sealed in a bellows or partial-bellows enclosure. The enclosure may have convolutions over substantially its entire length which permits it to flex easily in the direction of load cell bending. The enclosure is made resistant to elastic buckling under torsional forces produced by off-center loading of the load cell by one or more rods spaced circumferentially about the enclosure and connecting together a number of the convolutions after the convolutions are aligned. The alignment and torsional stiffening resist elastic buckling of the enclosure and resulting error in the output of the load cell. 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.
A load cell comprising at least one beam having a central longitudinal axis, a force transducer mounted on the beam, enclosure means enclosing the portion of said beam bearing the force transducer, said enclosure means having a first end and a second end rigidly attached to said beam, said enclosure means including at least one convolution to render it flexible to loads applied along said longitudinal axis and means rigid relative to said convolution for reducing non-linear torsional deformation of said enclosure means under loads applied transversely to said longitudinal axis.
A load cell comprising a beam having a central longitudinal axis, a force transducer mounted on the beam, enclosure means enclosing the portion of said beam bearing the force transducer, said enclosure means having at least one convolution, and means rigid relative to the convolution connected thereto for increasing the resistance to torsional deformation of the enclosure means.
A method of hermetically sealing a load cell having at least one beam with a force transducer mounted thereon and having a longitudinal axis, comprising the steps of providing an enclosure to enclose the portion of said beam bearing the force transducer, providing at least one convolution in said enclosure to render it flexible to loads applied along the longitudinal axis of said beam, connecting relatively rigid means to said convolution to reduce the non-linear torsional deformation of said enclosure under loads applied transversely to the longitudinal axis of said beam, and rigidly attaching the ends of said enclosure to said beam.
Dependencies are inferred from the claim text.