Method and apparatus for testing shock absorbers and the like

Abstract

A transducer for placement in fixed relation to the axle/wheel assembly of a vehicle and adjacent to the body of the vehicle, the transducer cooperating with the vehicle body to form a reactance that has a magnitude proportional to the distance between the transducer and the vehicle body. The magnitude of the reactance thus varies in response to variations in distance between the vehicle body and the transducer when the body is caused to experience oscillation on the springs thereof. Such oscillation is damped by the vehicle shock absorbers. A capacitive transducer and an inductive transducer, both of which include a guard or shield which shields the transducer from ground. An oscillator circuit wherein the frequency of oscillation is determined by the above mentioned reactance, the oscillator circuit having a non-ground common to which the guard is connected. A method for testing shock absorbers by employment of the transducer and oscillator circuit which includes the steps of displacing the vehicle from a quiescent position to load the springs in the vehicle, releasing the vehicle body so that it can return to the quiescent position and measuring the time variation of the reactance as the vehicle body vibrationally returns to the quiescent condition so as to afford an objective evaluation of the damping action of the vehicle shock absorbers.