US4563905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shaft torquemeter
Assignee: S HIMMELSTEIN AND Co
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Filing: 1984-08-27
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Granted: 1986-01-14
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Expires: 2004-08-27
Abstract
Abstract A nonintrusive torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed in the shaft. The torquemeter includes an annular first coil disposed axially about the shaft, a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature therewith, structure for mounting the coil assembly coaxially about the shaft to include the shaft in the magnetic flux coupling path between the coils, and structure for providing a signal corresponding to the voltage developed in the pickup winding as a result of changes in the magnetic reluctance of the shaft resulting from torque developed therein. One of the coils is electrically excited to define an excitation winding, and the other of the coils serves as a pickup winding, with the coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance thereof.
Inventors
- 👤 Sydney Himmelstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:11
CPC Classifications
G; G01; G01L; G01L3/00; G01L3/02; G01L3/04; G01L3/10; G01L3/101; G01L3/102; G01L3/105
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
186 words
A torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed therein, said torquemeter comprising: an annular first coil constructed to be disposed coaxially about the shaft; a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature with said first coil; means for mounting said coils coaxially about the shaft to include the shaft in the magnetic flux coupling path between said coils; means for electrically exciting one of said coils to cause said one of said coils to comprise an excitation winding and the other of said coils to comprise a pickup winding, said coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance of the shaft; and means for providing a signal corresponding to a voltage developed in the pickup winding coil as a result of a change in the magnetic reluctance of the shaft resulting from torque developed in the shaft.
Claim 2
Dependent Claim
186 words
A torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed therein, said torquemeter comprising: an annular first coil constructed to be disposed coaxially about the shaft; a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature with said first coil; means for mounting said coils coaxially about the shaft to include the shaft in the magnetic flux coupling path between said coils; means for electrically exciting one of said coils to cause said one of said coils to comprise an excitation winding and the other of said coils to comprise a pickup winding, said coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance of the shaft; and means for providing a signal corresponding to a voltage developed in the pickup winding coil as a result of a change in the magnetic reluctance of the shaft resulting from torque developed in the shaft.
Claim 3
Dependent Claim
205 words
A torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed therein, said torquemeter comprising: an annular first coil constructed to be disposed coaxially about the shaft; a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature with said first coil; means for mounting said coils coaxially about the shaft to include the shaft in the magnetic flux coupling path between said coils; means for electrically exciting one of said coils to cause said one of said coils to comprise an excitation winding and the other of said coils to comprise a pickup winding, said coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance of the shaft; means for providing a signal corresponding to a voltage developed in the pickup winding coil as a result of a change in the magnetic reluctance of the shaft resulting from torque developed in the shaft; and an annular magnetic core structure extending about said coils and defining with said shaft a low reluctance magnetic path.
Claim 4
Dependent Claim
205 words
A torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed therein, said torquemeter comprising: an annular first coil constructed to be disposed coaxially about the shaft; a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature with said first coil; means for mounting said coils coaxially about the shaft to include the shaft in the magnetic flux coupling path between said coils; means for electrically exciting one of said coils to cause said one of said coils to comprise an excitation winding and the other of said coils to comprise a pickup winding, said coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance of the shaft; means for providing a signal corresponding to a voltage developed in the pickup winding coil as a result of a change in the magnetic reluctance of the shaft resulting from torque developed in the shaft; and an annular magnetic core structure extending about said coils and defining with said shaft a low reluctance magnetic path.
Claim 5
Dependent Claim
200 words
A torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed therein, said torquemeter comprising: an annular first coil constructed to be disposed coaxially about the shaft; a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature with said first coil; means for mounting said coils coaxially about the shaft to include the shaft in the magnetic flux coupling path between said coils; means for electrically exciting one of said coils to cause said one of said coils to comprise an excitation winding and the other of said coils to comprise a pickup winding, said coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance of the shaft; means for providing a signal corresponding to a voltage developed in the pickup winding coil as a result of a change in the magnetic reluctance of the shaft resulting from torque developed in the shaft; and shielding means extending about said coils for shielding the coils from external magnetic fields.
Claim 6
Dependent Claim
200 words
A torquemeter for measuring torque in a shaft having variable reluctance as a result of torque stresses developed therein, said torquemeter comprising: an annular first coil constructed to be disposed coaxially about the shaft; a second coil wound about the first coil coaxially of the annular axis of the first coil to be in space quadrature with said first coil; means for mounting said coils coaxially about the shaft to include the shaft in the magnetic flux coupling path between said coils; means for electrically exciting one of said coils to cause said one of said coils to comprise an excitation winding and the other of said coils to comprise a pickup winding, said coils being effectively uncoupled in the absence of torque in the shaft and being variably coupled as an incident of torque being developed in the shaft causing a corresponding change in the reluctance of the shaft; means for providing a signal corresponding to a voltage developed in the pickup winding coil as a result of a change in the magnetic reluctance of the shaft resulting from torque developed in the shaft; and shielding means extending about said coils for shielding the coils from external magnetic fields.
Claim 7
Dependent Claim
19 words
The torquemeter of claim 1, 2, or 3 wherein said means for providing a signal includes a voltage amplifier.
Claim 8
Dependent Claim
23 words
The torquemeter of claim 1, 2, or 3 wherein said electrically extending means comprises means for providing a constant alternating current electrical supply.
Claim 9
Dependent Claim
32 words
The torquemeter of claim 1, 2, or 3 wherein said means for providing a signal includes a phase detector for comparing the phases of said signal with that of the excitation winding.
Claim 10
Dependent Claim
14 words
The torquemeter of claim 2 wherein said core structure comprises a split annular structure.
Claim 11
Dependent Claim
14 words
The torquemeter of claim 3 wherein said shielding means comprises a split annular structure.
References Cited (Backward Citations)
USRE26501E
Cited
GB442441A
Cited
US2511178A
Cited
GB762963A
Cited
US3013205A
Cited
US3441886A
Cited
US3501950A
Cited
US3531748A
Cited
US3717029A
Cited
US3531749A
Cited
US3800591A
Cited
US3827506A
Cited
USRE28899E
Cited
US3961525A
Cited
SU657281A1
Cited
SU597932A2
Cited
US4142591A
Cited
US4381684A
Cited
US4320463A
Cited
JPS57192836A
Cited
US4412198A
Cited
US4479390A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-13 | 1989-07-15 | 1990-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-13 | 1993-07-15 | 1994-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-13 | 1997-07-15 | 1998-01-14 | $7700.00 | Window Closed / Lapsed |