US3659631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controller for a pulsed servovalve
Assignee: Moore Business Forms Inc
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Filing: 1970-08-05
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Granted: 1972-05-02
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Expires: 1990-08-05
Abstract
Abstract An exhaust and pressure solenoid is operated by a circuit which generates a repetitive sawtooth signal waveform upon which is superimposed an input representing a desired control signal for regulating the flow of an operating fluid to a device such as a tension controller or brake. The orifices of the exhaust and pressure solenoids are duty cycle modulated at the repetitive frequency of the sawtooth signal and their respective orifice sizes are varied in accordance with the input signal.
Inventors
- 👤 John Peter Rakoske
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:16
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0635; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87169; Y10T137/87217
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
144 words
A circuit for controlling the application of fluid to a device operated thereby in response to input signals, comprising; means for generating a repetitive reference signal having a sawtooth waveform, means responsive to said reference signal and said input signals to form therefrom a combined signal, means for comparing said combined signal with a threshold reference leVel to produce an intermediate signal when said combined signal exceeds said threshold level, said means for comparing includes two channels each responsive to said combined signal and each having different threshold reference levels so that each channel operates on a different polarity of said combined signal, one of said channels controls the egress of fluid and the other channel controlling the ingress of fluid, and means controlled by said intermediate signal to regulate the flow the fluid by varying the duty cycle operation of said controlled means.
Claim 2
Dependent Claim
144 words
A circuit for controlling the application of fluid to a device operated thereby in response to input signals, comprising; means for generating a repetitive reference signal having a sawtooth waveform, means responsive to said reference signal and said input signals to form therefrom a combined signal, means for comparing said combined signal with a threshold reference leVel to produce an intermediate signal when said combined signal exceeds said threshold level, said means for comparing includes two channels each responsive to said combined signal and each having different threshold reference levels so that each channel operates on a different polarity of said combined signal, one of said channels controls the egress of fluid and the other channel controlling the ingress of fluid, and means controlled by said intermediate signal to regulate the flow the fluid by varying the duty cycle operation of said controlled means.
Claim 3
Dependent Claim
27 words
A circuit as in claim 1 wherein said means for generating includes means for modifying the repetition rate of said reference signal at a predetermined sweep frequency.
Claim 4
Dependent Claim
28 words
A circuit as in claim 1 wherein the difference in the amplitude of said threshold reference levels is substantially equal to the amplitude of said repetitive reference signal.
Claim 5
Dependent Claim
46 words
A circuit as in claim 3 wherein said controlled means includes a solenoid operated valve in each channel and having a control coil for actuating a valve member to open or close a fluid inlet or outlet in response to the intermediate signal in each channel.
Claim 6
Dependent Claim
48 words
A circuit as in claim 4 wherein said means for generating includes a cyclic current generator, means for integrating the current from said current generator, and means responsive to said integrated current for determining the repetitive operation of said cyclic current generator to establish said repetitive reference signal.
Claim 7
Dependent Claim
47 words
A circuit as in claim 5 wherein each of said valve members is duty cycle modulated at the repetitive rate of said reference signal from an open to a closed position in accordance with said input signal thereby varying the effective orifice size of said valve members.
Claim 8
Dependent Claim
39 words
A circuit as in claim 6 wherein the effective orifice established by said duty cycle modulated valve members is determined by the time interval during which said reference signal exceeds said threshold reference level in each of said channels.
References Cited (Backward Citations)
US2741088A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |