Compact force transducer with mechanical motion amplification

A force transducer comprising

• a pair of rigid force summing members formed of a material which extend generally in a first direction with one of said force summing members receiving a force-to-be-measured along the first direction;
• first and second beam members;
• said force summing members coupling said beam members to form a parallelogram structure whereby said force-to-be-measured causing said beam members to flex resiliently to produce a relative displacement d of the force summing members with respect to one another measured along said first direction and to produce a counter force to the force-to-be measured, said parallelogram structure being highly resistant to moments and forces tending to cause movement of said beam members not along the first direction,
• first and second sensor members rigidly each coupled to an associated one of said first and second beam members when it is flexed through the application of the force-to-be-measured,
• a plurality of conductive plates,
• said first beam member supporting two of said conductive plates on opposite sides of said first sensor member, and said second sensor member having two arm portions positioned on opposite sides of said first sensor member and each supporting another one of said conductive plates disposed in parallel spaced relationship with said conductive plates on said first sensor member to produce two variable capacitance gaps g, whereby the displacement d simultaneously produces a closing of one of said gaps g and the opening of the other of said gaps g,
• said members being oriented and coupled such that conductive plates in said parallel spaced relationship remain substantially parallel during a change .DELTA.g in said spacing g in response to said displacement d and .DELTA.g, and therefore the associated capacitance, is proportional to the force-to-be-measured.