Sundstrand Data Control, Inc.

Sundstrand Corporation

Mitchell J Novack

Brian L Norling

Frederick V Holdren

Rand H Hulsing, Ii

James R Woodruff

Peter H LaFond

Graeme A Blake

Charles J Rupnick

A stress isolation technique for an accelerometer of the type that has a reed that includes a paddle, a support, and flexures connecting the paddle to an area of the support. The support includes one or more mounting pads through which the reed is mounted. The area of the support adjacent to the flexures is divided into first and second portions, such that the flexures are connected to the first portion and such that the mounting pads are positioned solely on the second portion. The flexures are therefore isolated from stress coupled into the reed through the mounting pads.

Accelerometer with flexure isolation

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.

Preload system for accelerometer

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.

Accelerometer with mounting/coupling structure for an electronics

A push-pull accelerometer in which both force transducers lie in a common plane. Thus, when implemented in silicon micromachined device, both transducers can be fabricated from a single crystal layer, thereby producing transducers with closely matched common mode responses.

Accelerometer with coplanar push-pull force transducers

An improved accelerometer of the type that includes a proof mass suspended from a support by one or more flexures, such that the proof mass can pivot with respect to the support about a hinge axis. The proof mass includes a paddle attached to the flexures, the paddle having first and second paddle surfaces. The coil is mounted on the first paddle surface, and the accelerometer includes a stator for mounting the support and for forming a magnetic circuit with the coil. The improvement comprises positioning the flexures such that a plane containing the hinge axis and the center of mass of the proof mass is parallel to one of the paddle surfaces, and closer to one paddle surface than to the other paddle surface. In a preferred arrangement, the plane containing the hinge axis and the center of mass is approximately coplanar with one of the paddle surfaces and with the flexures.

Asymmetric flexure for pendulous accelerometer

A technique is described for tailoring the configuration of electrodes on a piezoelectric beam such that the tendency of the beam to vibrate in a predetermined flexure mode is enhanced. The mode has a predetermined longitudinal strain versus longitudinal position profile. At least two electrodes are mounted on the beam, and the configuration of at least one electrode varies as a function of longitudinal position, such that when a voltage difference is applied between the electrodes, the longitudinal force produced by the electrodes, as a function of longitudinal position, approximates the longitudinal strain versus longitudinal position profile. The configuration may be varied by varying the width of the electrode or the position of the electrode on the underlying beam surface.

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Kirkland, WA, United States of America

Mitchell J Novack