Patent ID: 7921728

Claim:
A force measuring device comprising: a sensor capacitor having a fixed surface and a movable surface substantially parallel to the fixed surface; at least one spring assembly positioned between the fixed surface and the movable surface, wherein the at least one spring assembly comprises a conical washer having an inside edge of the conical washer that is wider than an outside edge of the conical washer; at least one spring assembly to alter in height in response to a force applied perpendicular to the movable surface and to cause a change in a gap between the fixed surface and the movable surface, wherein the conical washer is stacked with other conical washers to form the at least one spring assembly; a circuit to generate a measurement of the force based on an algorithm that considers a change in a capacitance of the sensor capacitor; and a reference capacitor to adjust the measurement based on at least one environmental condition.