US 4,854,179 AGranted

Coaxial load cell

AssigneeBLH Electronics, Inc.

InventorRolf P. Haggstrom

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Abstract

An electrical strain-gaged load cell whose central and peripheral load-transmitting portions are coaxial with one another about an axis of applied loading includes intermediate interconnections formed by several planar-surfaced elongated shear-sensing beam elements whose opposite ends are integral with the coaxial portions and whose directions of elongation are essentially those of chords across the substantially annular spacing between the coaxial portions. Even in cells of small size, the relatively large chordal lengths of the beams, and the relatively sizable access spaces which may be accommodated alongside them, allow for convenient and facile installation of strain gages which will electrically characterize shear strains induced in the beams as they share transmission of the applied loading. Relatively massive end connections by which the beams connect with the coaxial portions are cantilevered radially inwardly and outwardly of the coaxial portions, angularly between the sites of the beams, to provide sturdy supports which will avoid undesirable end effects and, at the same time, will enable overall size and bulk of the cell to be minimized in designs rated for various capacities.

Claims11

Dependent claims

Strain gage transducer apparatus comprising a substantially rigid load-receiving portion of elastically-deformable material adapted to receive a load applied to it along an axis, said load-receiving portion being closely-spaced to a support portion, means for integrally interconnecting and maintaining said portions in closely-spaced relation in a first direction that is transverse to the axis along which the load is applied to said load-receiving portion, said means including stress-responsive, elongated sensing beam means having flat side surfaces whose elastic deformations characterize loading-induced shear stresses, said beam means being disposed substantially parallel to the axis along which the load is applied and transverse to the first direction,

said means for integrally interconnecting and maintaining said load-receiving portion and said support portion further including large, adjacent spaced rigid end connections projecting from one of said portions toward the other and from said other to said one of said portions, respectively, said end connections being spaced apart laterally substantially transversely both to said axis and to the first direction, said sensing beam means being integral with and held at opposite ends by tapered ends of said adjacent rigid end connections, which tapered ends are opposite said load receiving portion and said support portion and, said beam means extending substantially transversely to said end connections across the lateral spacing between said end connections, and strain gage means fixed with said flat side surfaces of said beam means so as to be responsive to strain induced by loading transmitted between said load-receiving portion and said support portion through said end connections and said beam means.

A load cell comprising substantially coaxial center and outer load-receiving and load-supporting portions constituting action and reaction members for loading applied substantially along an axis about which said portions are coaxial, said portions being radially separated by an annular region therebetween, a plurality of sensing beam elements having gage-mounting surfaces, said beam elements being disposed in said region at spaced angular positions about said axis each with a direction of elongation substantially transverse to said axis and to a radius from said axis, a plurality of end connections some of which project substantially radially outward from the center portion in said region and others of which project substantially radially inward from the outer portion in said region, opposite ends of each of said beam elements being fixed with and held by end connections which extend radially inward and outward, respectively, and strain gage means fixed with surfaces of said beam elements so as to be responsive to elastic deformations thereof induced by load transmitted between said center and outer portions.

Dependencies are inferred from the claim text.