US4301683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elastic surface wave accelerometer
Assignee: Thales SA
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Filing: 1979-11-27
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Granted: 1981-11-24
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Expires: 1999-11-27
Abstract
Abstract The invention relates to an accelerometer comprising at least one elastic plate propagating elastic surface waves, to which a normal force is applied resulting from the action of the acceleration which is to be measured on a solid or liquid body of predetermined mass. The measurement of the deviation in frequency of the oscillator of which the plate is a part gives an indication of the value of the normal component of the acceleration.
Inventors
- 👤 Pierre Hartemann
- 👤 Jean-Paul Castera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:22
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/097; G01P15/0975
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
156 words
An accelerometer using elastic surface waves, comprising: a frame; at least one elastic plate having opposing edges supported in said frame and subjected to the acceleration which is to be measured; means for emitting and means for receiving elastic surface waves on a front surface of said plate; amplifying means connecting said emitting means and said receiving means, so as to form an oscillator, the oscillation frequency of which is modulated by said acceleration; means for detecting the modulation of said oscillation frequency; mass means responsive to said acceleration for applying to the back surface of said plate a force causing deformation of said plate, said force being always located in a plane containing the normal to a flat central area of said back surface whatever is the direction of said acceleration; said mass means comprising a solid body having at least one flat central area and a rolling element pinched between said flat central areas.
Claim 2
Dependent Claim
156 words
An accelerometer using elastic surface waves, comprising: a frame; at least one elastic plate having opposing edges supported in said frame and subjected to the acceleration which is to be measured; means for emitting and means for receiving elastic surface waves on a front surface of said plate; amplifying means connecting said emitting means and said receiving means, so as to form an oscillator, the oscillation frequency of which is modulated by said acceleration; means for detecting the modulation of said oscillation frequency; mass means responsive to said acceleration for applying to the back surface of said plate a force causing deformation of said plate, said force being always located in a plane containing the normal to a flat central area of said back surface whatever is the direction of said acceleration; said mass means comprising a solid body having at least one flat central area and a rolling element pinched between said flat central areas.
Claim 3
Dependent Claim
32 words
An accelerometer according to claim 1, wherein said emitting and receiving means consist of electromechanical transducers arranged on one surface of said plate and exchanging elastic surface waves in a predetermined direction.
Claim 4
Dependent Claim
17 words
An accelerometer according to claim 2, wherein the electromechanical transducers consist of two combs with intercalated teeth.
Claim 5
Dependent Claim
42 words
An accelerometer according to claim 1, wherein said emitting and receiving means consist of two networks reflecting elastic surface waves, arranged on one side of said plate and constituting a resonant cavity and at least one electromechanical tranducer located inside said cavity.
Claim 6
Dependent Claim
14 words
An accelerometer according to claim 1, wherein said plate consists of a piezoelectric material.
Claim 7
Dependent Claim
12 words
An accelerometer according to claim 5, wherein the piezoelectric material is quartz.
Claim 8
Dependent Claim
13 words
An accelerometer according to claim 5, wherein the piezoelectric material is lithium niobate.
Claim 9
Dependent Claim
41 words
An accelerometer according to claim 1, wherein said rolling element is a roller mechanically connected to said body and having a line or contact with said back surface; said line of contact having a direction of least responsiveness to said acceleration.
Claim 10
Dependent Claim
27 words
An accelerometer according to claim 1, wherein said rolling element is a ball mechanically connected to said body and having a point of contact with the plate.
Claim 11
Dependent Claim
41 words
An accelerometer according to claim 9, comprising two parallel plates, the solid body being located between the two plates, and two balls located on each side of the solid body and each having a point of contact with the two plates.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-23 | 1985-05-25 | 1985-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-23 | 1989-05-25 | 1989-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-23 | 1993-05-25 | 1993-11-24 | $7700.00 | Window Closed / Lapsed |