US Patent 7334487 Load cell with roberval mechanism

Disclosed is a load cell including a Roberval mechanism having two parallel arms between a fixed end and a movable end, and four strain-generating portions, arranged such that two of the strain-generating portions are coupled to each other on each of the two arms. In certain embodiments, the four strain-generating-portions all have the same thickness, and the two arms include a first arm having strain gauges adhered to each of two of the strain-generating portions coupled to each other, and a second arm having a thickness smaller than that of the first arm.