Abstract: An accelerometer device comprises a silicon semiconductor member having a mass mounted on a support by integral beams extending between the mass and support to permit movement of the mass in response to acceleration. Piezoresistive sensors are accommodated in the beams for sensing strain in the beams during movement of the mass to provide an output signal from the device corresponding to the acceleration. The beams each have an end secured to the support and an end secured to the mass and taper intermediate the beam ends to provide a high and substantially uniform strain throughout the tapered section of the beam. The piezoresistive sensor is accommodated in the tapered beam section to be responsive to that high, uniform strain.

Abstract: An accelerometer is shown with improved drop resistance for regulating automotive safety air-bag systems and the like. The device comprises a member of silicon semiconducting material having a central seismic mass mounted on a surrounding support by intervening beams, a pair of beams extending from each of four sides of the mass to the support and the mass being otherwise free of connection to the support to permit movement of the mass along an axis perpendicular to the plane of the support in highly sensitive response to acceleration forces along that axis. Each beam extends from a location near an end of one side of the mass so that the two beams extending from each side of the mass are widely spaced relative to each other to oppose rotational or twisting movement of the mass in response to off-axis acceleration forces to prevent damage to the beams during dropping of the accelerometer to the extent possible consistent with providing the desired sensitivity of response.