Abstract: An acoustic emission automotive crash sensor arrangement which includes a continuous loop type wave guide welded at a number of locations to the vehicle structures likely to be deformed upon impact of the vehicle with an object. The ends of the loop are secured to a piezoelectric crystal, the output of which is digitized and compared in a microprocessor to preprogrammed threshholds for several different parameters of the acoustic emission event to determine whether an impact of sufficient severity has occurred to require actuation of an occupant restraint. In other embodiments: the ends of the wave guide may be secured to individual crystals; the loop type wave guide may be connected to all or certain of the vehicle structures by branch wave guides; and individual wave guides may be connected between the vehicle structures and the crystal.

Abstract: A cantilever type velocity sensor which includes a unitary elongated frame member mounted on spaced walls of a base of dielectric material. A planar spring member has one end portion thereof mounted to an integral adjustable portion of the frame and the other free end thereof mounting a mass engageable with another integral adjustable portion of the frame. The first portion is adjustable to set the preload force and the second portion is adjustable to set the travel distance between the mass and the contact means of the sensor. A third integral adjustable portion of the frame limits vibrational movement of the spring member relative to the frame. A resilient stop means is engageable by the mass upon actuation of the sensor to obviate contact bounce and ensure adequate closure time. Both the contact means, in the form of a columnar coil spring, and an integral terminal portion of the frame, are monitored by a resistor connected thereacross.