Patent US4186324A successfully refreshed from Google Patents.
US4186324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear accelerometer with piezoelectric suspension
Assignee: LUCAS SCHAEVITZ Inc A Corp OF NJ
•
Filing: 1978-05-11
•
Granted: 1980-01-29
•
Expires: 1998-05-11
Abstract
Abstract A piezoelectric flexible arm member is mounted to a base at one end and supports a torque coil in a magnetic field at its other end. The torque coil comprises a seismic element disposed to be moved in accordance with acceleration forces applied thereto. A voltage is produced across the piezoelectric flexure arm when movement of the torque coil causes it to flex. The torque coil may include means to induce a signal in a position detector circuit representative of the position thereof. Both the signals from the piezoelectric member and the position detector may be used as error signals in a servo amplifier system to provide restoring forces to the torque coil and to produce an output signal representative of acceleration forces. A third conventional error signal may also be employed in the system.
Inventors
- 👤 Robert E. Hartzell, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:15
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/11; G01P15/09; G01P15/0922; G01P15/13; G01P15/132
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
89 words
Means for generating output signals representing acceleration forces comprising: a. a torque coil; b. means for producing a magnetic field; c. base means; d. a piezoelectric flexure member connected to said base means and supporting said torque coil in said magnetic field; e. said piezoelectric flexure member permitting said torque coil to be moved in said magnetic field to produce voltage signals across said piezoelectric member in accordance with the movement of said torque coil; and f. utilization means for receiving the voltage signals produced by said piezoelectric member.
Claim 2
Dependent Claim
89 words
Means for generating output signals representing acceleration forces comprising: a. a torque coil; b. means for producing a magnetic field; c. base means; d. a piezoelectric flexure member connected to said base means and supporting said torque coil in said magnetic field; e. said piezoelectric flexure member permitting said torque coil to be moved in said magnetic field to produce voltage signals across said piezoelectric member in accordance with the movement of said torque coil; and f. utilization means for receiving the voltage signals produced by said piezoelectric member.
Claim 3
Dependent Claim
110 words
Means for generating output signals representing acceleration forces comprising: a. a torque coil; b. means for producing a magnetic field; c. base means; d. a piezoelectric flexure member connected to said base means and supporting said torque coil in said magnetic field; e. said piezoelectric flexure member permitting said torque coil to be moved in said magnetic field to produce voltage signals across said piezoelectric member in accordance with the movement of said torque coil; f. a position sensor to detect the positions of said torque coil and to generate electrical signals representative of said positions; and g. utilization means for receiving the voltage signals produced by said piezoelectric member.
Claim 4
Dependent Claim
110 words
Means for generating output signals representing acceleration forces comprising: a. a torque coil; b. means for producing a magnetic field; c. base means; d. a piezoelectric flexure member connected to said base means and supporting said torque coil in said magnetic field; e. said piezoelectric flexure member permitting said torque coil to be moved in said magnetic field to produce voltage signals across said piezoelectric member in accordance with the movement of said torque coil; f. a position sensor to detect the positions of said torque coil and to generate electrical signals representative of said positions; and g. utilization means for receiving the voltage signals produced by said piezoelectric member.
Claim 5
Dependent Claim
51 words
Means for generating output signals as set forth in claim 2 wherein said utilization means includes a servo amplifier for receiving the voltage signals generated by said piezoelectric member and the electrical signals produced by said position sensor to counter balance the movement of said torque coil caused by acceleration forces.
Claim 6
Dependent Claim
42 words
Means for generating output signals as set forth in claim 3 wherein said torque coil includes a conductive element connected thereto coupled to said position sensor to vary the electrical signals produced thereby in accordance with the movements of said torque coil.
Claim 7
Dependent Claim
40 words
Means for generating output signals as set forth in claim 4 wherein current sensing means is connected to said torque coil to generate signals representing the movements and acceleration of said torque coil to be applied to an output circuit.
Claim 8
Dependent Claim
21 words
Means for generating output signals as set forth in claim 5 wherein said torque coil is disposed around a permanent magnet.
Claim 9
Dependent Claim
30 words
Means for generating output signals as set forth in claim 3 wherein additional error signals are fed back from the output circuit to the input circuit of said servo amplifier.
References Cited (Backward Citations)
US3120622A
Cited
US3389275A
Cited
US3435323A
Cited
US3727097A
Cited
US3797320A
Cited
US4020687A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-28 | 1983-07-30 | 1984-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-28 | 1987-07-30 | 1988-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-28 | 1991-07-30 | 1992-01-29 | $7700.00 | Window Closed / Lapsed |