Load cell

Claim 2

A load cell for measurement of loads transmitted from an impact receiving member to a support structure, the load cell comprising: a support plate to which the impact receiving member is attachable and a base plate adapted to be mounted on the support structure, the support plate and base plate being positioned in spaced parallel relationship to each other, four strain beams having substantially identical stress versus strain curves interposed between the spaced support and base plates, positioning means securing each end of the beams to one of the plates with the longitudinal axis of each beam paralleling the plate surface and with the beams arranged to form the sides of a square, load transfer means coupling each beam to the other plate centrally of the positioning means, and strain gage means positioned on the sides of the beams contiguous the support and base plates in predetermined relationship to the load transfer means to sense the deflection of each beam under load.

Claim 3

A load cell according to claim 1, in which: the positioning means for each beam comprises at each end of the beam a pivot shaft supported on an end pivot support member extending from the one plate toward the other, the axes of the pivot shafts lying in a plane substantially paralleling the plane of the one plate surface.

Claim 4

A load cell according to claim 2, in which: the load transfer means for each beam comprises: a pivot shaft projecting through each beam centrally of the pivot shafts at each end of the beam and having its axis parallel to and in the same plane as the axes of the end pivot shafts, and support means positioning and retaining each central pivot shaft on the other plate.

Claim 5

A load cell according to claim 3, in which: the base plate and the support plate are of substantially uniform shape, and both plates have provisions for attachment to the respective support structure and impact receiving member.

Claim 6

A load cell according to claim 2, in which: the end pivot support members are attached to the base plate and extend toward the support plate.

Claim 7

A load cell according to claim 5, in which: the end pivot support member at one end of each beam is fixedly attached to the base plate, and the end pivot support member at the other end of each beam is pivotally attached to the base plate.

Claim 8

A load cell according to claim 6, in which: the load transfer means for each beam comprises a pivot shaft projecting through each beam centrally of the pivot shafts at each end of the beam and having its axis parallel to and in the same plane as the axes of the end pivot shafts, and support means positioning and retaining each central pivot shaft a distance from the surface of the support plate.

Claim 9

A load cell according to claim 7, in which: the support means comprises arms fixed to the support plate and projecting toward the base plate.

Claim 10

A load cell according to claim 2, in which: the end pivot support members comprise posts attached to the support plate which project toward the base plate.

Claim 11

A load cell according to claim 9, in which: the load transfer means for each beam comprises a pivot shaft projecting through each beam centrally of the pivot shafts at each end of the beam and having its axis parallel to and in the same plane as the axes of the end pivot shafts, and support means positioning and retaining each central pivot shaft in spaced relationship to the surface of the base plate.

Claim 12

A load cell according to claim 10, in which: the support means comprises a four legged spider attached to the base plate, the central pivot shafts projecting from the end face of each leg of the spider.

Claim 13

A load cell for measurement of loads transmitted from a vehicle bumper to a vehicle frame member supporting the bumper, the load cell comprising: a support plate to which the vehicle bumper is attached and a base plate mounted on an end of the vehicle frame member, the support plate and base plate being positioned in spaced parallel relationship to each other, four strain beams having substantially identical stress versus strain curves interposed between the spaced support and base plates, positioning means securing each end of the beams to one of the plates with the longitudinal axis of each beam paralleling the plate surface and with the beams arranged to form the sides of a square, load transfer means coupling each beam to the other plate centrally of the positioning means, and strain gage means positioned on the side of the beams contiguous the support and base plates in predetermined relationship to the load transfer means to sense the deflection of each beam under load.

Claim 14

A load cell for measurement of loads transmitted from a vehicle bumper to a vehicle frame member supporting the bumper, the load cell comprising: a support plate to which the vehicle bumper is attached and a base plate mounted on an end of the vehicle frame member, the support plate and base plate being positioned in spaced parallel relationship to each other, four strain beams having substantially identical stress versus strain curves interposed between the spaced support and base plates, positioning means securing each end of the beams to one of the plates with the longitudinal axis of each beam paralleling the plate surface and with the beams arranged to form the sides of a square, load transfer means coupling each beam to the other plate centrally of the positioning means, and strain gage means positioned on the side of the beams contiguous the support and base plates in predetermined relationship to the load transfer means to sense the deflection of each beam under load.