US3628042A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system
Assignee: CHARLES EQUIPMENT CO
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Filing: 1969-07-03
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Granted: 1971-12-14
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Expires: 1989-07-03
Abstract
Abstract A control system using a motive source and connected hydrostatic transmission to drive a load at a speed determined by the volume of fluid flowing in the transmission. A comparator and actuator change the volume of fluid flow in proportion to the deviation between a feedback signal and a control signal. The feedback signal is generated by a sensor responsive to the output of the transmission. The control signal has a value dependent upon the type of load connected to the transmission.
Inventors
- 👤 Charles J Jacobus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:35
CPC Classifications
H; H02; H02P; H02P29/00; H02P29/0016; F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/46; F16H61/47
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
333 words
In a system for supplying an electric load with AC power of variable frequency and having an AC generator providing an AC output to said electric load with a frequency dependent upon the speed of rotation of an input shaft, a control for providing a selectable variable frequency output to said electric load, comprising: a source of rotating motive power; hydrostatic transmission means having an input coupling connected to said motive source, an output coupling connected to said input shaft of said AC generator, variable displacement pump means driven by said input coupling, fixed displacement motor means connected to said output coupling, means including a source of fluid and tubing means for interconnecting said source of fluid to said pump means and said motor means, and adjustment means for selecting different displacements of fluid by said pump means to vary the amount of fluid transmitted through said tubing means to said fixed displacement motor means in order to select different speeds of rotation of said output coupling for a given speed of rotation of said input coupling; feedback means coupled to the AC output of said AC generator for generating an AC feedback signal varying in frequency in proportion to the frequency of said AC output to said electric load; frequency load selector means for generating a control signal having a selectable frequency which can be varied; comparator means having a first input coupled to said feedback means and a second input coupled to said frequency load selector means for comparing the frequency of said AC feedback signal with the frequency of said control signal anD producing a command in proportion to the frequency deviation between said signals; and actuator means responsive to said command for varying said adjustment means until said input shaft has a speed of rotation which produces an AC output to said electric load having a frequency which corresponds to the selected frequency; said frequency load selector means comprises a sweep generator for continuously sweeping a band of frequencies.
Claim 2
Dependent Claim
333 words
In a system for supplying an electric load with AC power of variable frequency and having an AC generator providing an AC output to said electric load with a frequency dependent upon the speed of rotation of an input shaft, a control for providing a selectable variable frequency output to said electric load, comprising: a source of rotating motive power; hydrostatic transmission means having an input coupling connected to said motive source, an output coupling connected to said input shaft of said AC generator, variable displacement pump means driven by said input coupling, fixed displacement motor means connected to said output coupling, means including a source of fluid and tubing means for interconnecting said source of fluid to said pump means and said motor means, and adjustment means for selecting different displacements of fluid by said pump means to vary the amount of fluid transmitted through said tubing means to said fixed displacement motor means in order to select different speeds of rotation of said output coupling for a given speed of rotation of said input coupling; feedback means coupled to the AC output of said AC generator for generating an AC feedback signal varying in frequency in proportion to the frequency of said AC output to said electric load; frequency load selector means for generating a control signal having a selectable frequency which can be varied; comparator means having a first input coupled to said feedback means and a second input coupled to said frequency load selector means for comparing the frequency of said AC feedback signal with the frequency of said control signal anD producing a command in proportion to the frequency deviation between said signals; and actuator means responsive to said command for varying said adjustment means until said input shaft has a speed of rotation which produces an AC output to said electric load having a frequency which corresponds to the selected frequency; said frequency load selector means comprises a sweep generator for continuously sweeping a band of frequencies.
Claim 3
Dependent Claim
28 words
The control of claim 1 wherein said source of rotating motive power comprises a powered motor capable of producing a sustained torque to continuously drive said input coupling.
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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) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |