Abstract: An improved preload system for an accelerometer in which an acceleration sensitive structure is clamped between first and second clamping members. The acceleration sensitive structure includes a paddle supported such that the paddle has a degree of freedom along a sensing axis. The accelerometer further includes a case within which the acceleration sensitive structure and clamping members are mounted. The preload system comprises an internal mounting surface in the case that faces in a first direction along the sensing axis, and that contacts the second clamping member and prevents it from moving in a second direction opposite to the first direction. The preload system also includes a spring washer extending between the first clamping member and the case, such that the spring washer exerts a force on the first clamping member in the second direction. A positioning ring may also be provided between the first clamping member and spring washer, to laterally locate the first clamping member within the case.

Abstract: A mounting/coupling structure for use in an accelerometer to mount the electronics assembly with respect to the case, and to electrically couple the electronics assembly to the acceleration sensitive structure. The mounting/coupling structure may be positioned such that it provides gas damping for the paddle, and may also include means for holding the acceleration sensitive structure in a fixed position with respect to the case.

Abstract: In order to facilitate construction of a compact, lightweight servoed accelerometer with capacitive pick-off, a one-piece support frame, adapted to be inserted within a cylindrical housing, is used to support a pair of capacitor plates and a lightweight longitudinally reinforced pendulum or seismic mass having a paddle on one end. The paddle is positioned midway between the capacitor plates, thereby forming a pair of capacitors each having a capacitance on the order of 2 to 4 picofarads. Attached to the pendulum is an axle which in turn is supported between two flexures by means of jeweled pivoted bearings. The ends of the flexures are rigidly secured to the support frame, and a desired pressure of the bearings against the axle is maintained by means of adjustment screws.

Abstract: In order to facilitate construction of a compact, lightweight servoed accelerometer with capacitive pick-off, a one-piece support frame, adapted to be inserted within a cylindrical housing, is used to support a pair of capacitor plates and a lightweight longitudinally reinforced pendulum or seismic mass having a paddle on one end. Attached to the pendulum is an axle which in turn is supported between two flexures by means of jeweled pivoted bearings. Also attached to the pendulum is a torque coil which interacts with a magnetic assembly, secured to the support frame, to restore the paddle to the midpoint between the capacitor plates when the pendulum has been subjected to an acceleration force.