# US 10,371,711 B2 · Damped linear accerelometer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,711 B2 - Document ID: US10371711B2 - Status: Granted - Kind: B2 - Application number: 15/454,249 - Filed: 2017-03-09 - Published: 2017-09-14 - Granted: 2019-08-06 - Earliest claimed: 2016-03-11 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Applicants: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Inventors: Bruno Fain; Aboubacar Chaehoi; Philippe Robert - Web page: https://patentgrep.com/patent/US10371711B2 ## CPC - G01P 1/003: {used for damping} - G01P 15/123: {by piezo-resistive elements, e.g. semiconductor strain gauges} - G01P 2015/0817: {for pivoting movement of the mass, e.g. in-plane pendulum} - G01P 2015/0882: {for providing damping of vibrations} - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) ## Abstract Linear accelerometer comprising a fixed part, a rotationally moving part in the plane of the accelerometer around an axis of rotation orthogonal to the plane of the accelerometer, the moving part comprising a centre of gravity distinct from the point of intersection of the axis of rotation and the plane of the accelerometer, means forming pivot link between the moving part and the fixed part, means for detecting the displacement of the moving part with respect to the fixed part, means for viscous damping the displacement of the moving part in said plane, said viscous damping means comprising interdigitated combs, at least one first comb on the moving part and at least one second comb on the fixed part (2), the first comb and the second comb being interdigitated. ## Claims ### Claim 1 A linear accelerometer comprising: a fixed part, a rotationally moving part in a plane of the accelerometer around an axis of rotation orthogonal to the plane of the accelerometer, the moving part comprising a center of gravity distinct from a point of intersection of the axis of rotation and the plane of the accelerometer, suspension means between the moving part and the fixed part, forming a pivot link between the moving part and the fixed part and limiting translational displacements of the moving part with respect to the fixed part, a detector for detecting the displacement of the moving part with respect to the fixed part, viscous damping means for damping the displacement of the moving part in said plane, said viscous damping means comprising interdigitated combs, at least one first comb on the moving part and at least one second comb on the fixed part, the first comb and the second comb being interdigitated and the first comb and the second comb being at the same electric potential. ### Claim 2 (depends on 1) The linear accelerometer according to claim 1, wherein the detector is distinct from the viscous damping means. ### Claim 3 (depends on 1) The linear accelerometer according to claim 1, wherein the fixed part comprises at least one outer portion surrounding the moving part and wherein the viscous damping means line a part at least of a periphery of the moving part. ### Claim 4 (depends on 3) The linear accelerometer according to claim 3, wherein the viscous damping means line the whole periphery of the moving part. ### Claim 5 (depends on 1) Linear The linear accelerometer according to claim 1, wherein said at least second comb of the fixed part and said at least first comb of the moving part are at a same electrical potential. ### Claim 6 (depends on 1) The linear accelerometer according to claim 1, wherein the moving part has a disc shape and wherein the first comb comprises fingers extending radially towards an outside of the moving part and the second comb comprises fingers extending radially from an outer portion of the fixed part to the moving part. ### Claim 7 (depends on 6) The linear accelerometer according to claim 6, wherein the fingers of the first comb and the fingers of the second comb are such that they have a central symmetry with respect to the axis of rotation of the moving part. ### Claim 8 (depends on 6) The linear accelerometer according to claim 6, wherein, each finger of the moving part comprising at least two faces, each face facing one face of a finger of the fixed part and at a given distance therefrom, at rest position of the moving part the given distance is identical for the two faces of the finger. ### Claim 9 (depends on 3) The linear accelerometer according to claim 3, wherein the moving part comprises a recess and the fixed part comprises an inner portion arranged in said recess and all or part of the suspension means suspend the moving part from the inner portion of the fixed part. ### Claim 10 (depends on 9) The linear accelerometer according to claim 9, wherein the suspension means comprise at least two beams extending between the moving part and the inner portion, said beams extending along two directions making a non-zero angle, comprised between 0° and 180° , said directions intersecting substantially at the intersection point of the axis of rotation and the plane of the accelerometer. ### Claim 11 (depends on 1) The linear accelerometer according to claim 1, wherein the detector is a piezoresistive detector. ### Claim 12 (depends on 1) The linear accelerometer according to claim 1, wherein the detector comprises at least two gauges mounted differentially, said gauges being aligned along an axis perpendicular to an axis going through the center of gravity of the moving part and the intersection point of the axis of rotation and the plane of the accelerometer. ### Claim 13 (depends on 9) The linear accelerometer according to claim 9, wherein the detector comprises at least two gauges mounted differentially, said gauges being aligned along an axis perpendicular to an axis going through the center of gravity of the moving part and the intersection point of the axis of rotation and the plane of the accelerometer and wherein the inner portion of the fixed part comprises several electrically independent zones enabling a “4-wire” measurement of the resistances of the gauges. ### Claim 14 (depends on 1) The linear accelerometer according to claim 1, comprising a cavity in which the moving part and the fixed part are housed and in which the pressure level is controlled. ### Claim 15 (depends on 14) The linear accelerometer according to claim 14, wherein the cavity is filled with viscous neutral gas, for example xenon or argon. ### Claim 16 (depends on 9) The linear accelerometer according to claim 9, wherein the suspension means comprise at least two beams extending between the moving part and the inner portion, said beams extending along two directions making an angle equal to 90°, said directions intersecting substantially at the intersection point of the axis of rotation and the plane of the accelerometer. ### Claim 17 (depends on 14) The linear accelerometer according to claim 14, wherein the cavity is filled with xenon or argon.