US3709253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve control with dither
Assignee: Marotta Scientific Controls Inc
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Filing: 1970-09-23
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Granted: 1973-01-09
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Expires: 1990-09-23
Abstract
Abstract This invention is an electric controller which superimposes an oscillating signal on a load signal with feedback for controlling the resultant output signal. More specifically the invention has a mechanical element, particularly a poppet valve, that is operated by a signal applied to an actuator coil; and the superimposed oscillating signal causes dither of the mechanical element to overcome static friction and hysteresis. In the preferred construction, the dither signal passes from an inverting amplified to a biasing driver network, and then to a push-pull amplifier that has feedback for producing the oscillations. The preferred construction augments the oscillation by use of a voltage sensitive resistor in the feedback circuit. The dither frequency becomes lower as the valve approaches closed position. This produces greater magnitude of the dither and a degree of impact that seals the valve with less pressure required to hold the valve closed.
Inventors
- 👤 G Spangenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:12
CPC Classifications
F; F16; F16K; F16K31/00; F16K31/12; F16K31/42; F16K31/423; H; H02; H02K; H02K33/00; H02K33/12; H02K33/14; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87153; Y10T137/87161; Y10T137/87169; Y10T137/87217; Y10T137/87225; Y10T137/87233; Y10T137/87241
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
185 words
Control appaRatus including an electrically operated actuator, a circuit to said actuator, means for supplying a load signal to the actuator circuit to energize said actuator, a feedback from the actuator circuit including an oscillating circuit that superimposes a dither signal on the load signal, and characterized by a mechanical element that is operated by said actuator, bearings in which the mechanical element has friction, the magnitude and the frequency of the dither signal being correlated with the inertia of the mechanical element and the electrical impedance of the actuator circuit to maintain a vibration of the mechanical element with resulting elimination of the static friction of the mechanical element on its bearings as a factor in the movement of the mechanical element in response to load signals to the actuator, characterized by the mechanical element being a poppet valve and the actuator including a magnetic coil that moves the poppet valve with respect to a valve seat, the dither signal vibrating the poppet valve toward and from said seat, and means for increasing the magnitude of the vibrations when the valve approaches closed position.
Claim 2
Dependent Claim
185 words
Control appaRatus including an electrically operated actuator, a circuit to said actuator, means for supplying a load signal to the actuator circuit to energize said actuator, a feedback from the actuator circuit including an oscillating circuit that superimposes a dither signal on the load signal, and characterized by a mechanical element that is operated by said actuator, bearings in which the mechanical element has friction, the magnitude and the frequency of the dither signal being correlated with the inertia of the mechanical element and the electrical impedance of the actuator circuit to maintain a vibration of the mechanical element with resulting elimination of the static friction of the mechanical element on its bearings as a factor in the movement of the mechanical element in response to load signals to the actuator, characterized by the mechanical element being a poppet valve and the actuator including a magnetic coil that moves the poppet valve with respect to a valve seat, the dither signal vibrating the poppet valve toward and from said seat, and means for increasing the magnitude of the vibrations when the valve approaches closed position.
Claim 3
Dependent Claim
220 words
Control apparatus including an electrically operated actuator, a circuit to said actuator, means for supplying a load signal to the actuator circuit to energize said actuator, a feedback from the actuator circuit including an oscillating circuit that superimposes a dither signal on the load signal, and characterized by an inverting amplifier through which energy is supplied to the circuit of the actuator, said feedback being connected with the actuator circuit on the outlet side of the amplifier and leading back to a summing juncture on the input side of the inverting amplifier, and a push-pull amplifier connected with the outlet side of the inverting amplifier, the feedback and oscillating circuit being connected across the push-pull amplifier and having an oscillating signal connection leading to the input side of the inverting amplifier, and further characterized by the mechanical element being a valve and the actuator including a magnetic coil that moves the valve between closed and open positions, a second mechanical element comprising a second valve and an actuator for the second valve including a second magnetic coil, both of the coils being connected across the push-pull amplifier with rectifiers constructed and arranged to energize one or the other of the coils selectively depending upon the polarity of the output load signal supplied to the push-pull amplifier by the inverting amplifier.
Claim 4
Dependent Claim
220 words
Control apparatus including an electrically operated actuator, a circuit to said actuator, means for supplying a load signal to the actuator circuit to energize said actuator, a feedback from the actuator circuit including an oscillating circuit that superimposes a dither signal on the load signal, and characterized by an inverting amplifier through which energy is supplied to the circuit of the actuator, said feedback being connected with the actuator circuit on the outlet side of the amplifier and leading back to a summing juncture on the input side of the inverting amplifier, and a push-pull amplifier connected with the outlet side of the inverting amplifier, the feedback and oscillating circuit being connected across the push-pull amplifier and having an oscillating signal connection leading to the input side of the inverting amplifier, and further characterized by the mechanical element being a valve and the actuator including a magnetic coil that moves the valve between closed and open positions, a second mechanical element comprising a second valve and an actuator for the second valve including a second magnetic coil, both of the coils being connected across the push-pull amplifier with rectifiers constructed and arranged to energize one or the other of the coils selectively depending upon the polarity of the output load signal supplied to the push-pull amplifier by the inverting amplifier.
Claim 5
Dependent Claim
19 words
The control apparatus described in claim 2 characterized by the selectively conducting elements of the push-pull amplifier being transistors.
Claim 6
Dependent Claim
124 words
Control apparatus including an electrically operated actuator, a circuit to said actuator, means for supplying a load signal to the actuator circuit to energize said actuator, a feedback from the actuator circuit including an oscillating circuit that superimposes a dither signal on the load signal, and characterized by there being two actuators, each of which includes a magnetic coil, a valve operated by one of the coils, a second valve operated by the other magnetic coil, the actuators being responsive to load signals of different polarities, the means for supplying the load signal including apparatus for selectively supplying load signals of different polarity, and the feedback being from the circuits of both actuators for superimposing dither signals on the load signals of both actuators.
Claim 7
Dependent Claim
124 words
Control apparatus including an electrically operated actuator, a circuit to said actuator, means for supplying a load signal to the actuator circuit to energize said actuator, a feedback from the actuator circuit including an oscillating circuit that superimposes a dither signal on the load signal, and characterized by there being two actuators, each of which includes a magnetic coil, a valve operated by one of the coils, a second valve operated by the other magnetic coil, the actuators being responsive to load signals of different polarities, the means for supplying the load signal including apparatus for selectively supplying load signals of different polarity, and the feedback being from the circuits of both actuators for superimposing dither signals on the load signals of both actuators.
Claim 8
Dependent Claim
21 words
The control apparatus described in claim 4 characterized by the feedback including the same oscillating circuit for both of the actuators.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |