Patent US3774641A successfully refreshed from Google Patents.
US3774641A
Expired / Lapsed
US
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Electrohydraulic control arrangement for hydraulic actuators
Assignee: Individual
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Filing: 1972-04-11
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Granted: 1973-11-27
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Expires: 1992-04-11
Abstract
Abstract A control arrangement for hydraulic actuators in which two hydraulic transmission lines communicating with the actuator are closed when the control slide of a control valve is in neutral position. Inlet and return lines communicate with the hydraulic transmission lines in alternate operative positions of the control slide. The control slide is actuated by a piston moving within a control cylinder. Working fluid is applied to the control cylinder through electromagnetically actuated valves. A remote control lever provides an adjustable input parameter through a transducer. The electromagnetically actuated valves are operated by a regulating amplifier as a function of the input parameter established by the remote control lever. Two flow lines communicate with the control cylinder and are connected to the inlet and return lines by two electromagnetically actuated valves. Threshold switching circuits are connected between the signal amplifiers used to energize the electromagnetically actuated valves and the regulating amplifier.
Inventors
- 👤 R Mindner
- 👤 K Adler
- 👤 H Flaschar
- 👤 K Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:38
CPC Classifications
F; F15; F15B; F15B9/00; F15B9/02; F15B9/08; F15B9/09; B; B64; B64C; B64C13/00; B66; B66C; B66C13/00; B66C13/52; B66C13/54; B66C2700/00; B66C2700/08; B66C2700/085; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86582; Y10T137/86614
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
193 words
An electrohydraulic control arrangement for hydraulic operating means operative in two directions comprising, in combination, a control valve with control slides; two hydraulic transmission lines communicating with said operating means and closed by said control slide when in neutral position in said control valve; inlet line means communicating with one of said hydraulic transmission lines when said control slide is in a first operative position; return line means communicating with the other one of said hydraulic transmission lines when said control slide is in a second operative position; control piston means movable within a control cylinder and actuating said control slide; electromagnetically actuated valves for applying working fluid to said control cylinder; remote control lever means for providing an adjustable input parameter; regulating amplifier means actuating said electromagnetic valves as a function of said input parameter; two flow lines communicating with said control cylinder and connected to said inlet line means and said return line means by two of said electromagnetically actuated valves; signal amplifying means connected to said electromagnetically actuated valves for actuating said electromagnetically actuated valves; and threshold switching means connected between said signal amplifying means and said regulating amplifying means.
Claim 2
Dependent Claim
193 words
An electrohydraulic control arrangement for hydraulic operating means operative in two directions comprising, in combination, a control valve with control slides; two hydraulic transmission lines communicating with said operating means and closed by said control slide when in neutral position in said control valve; inlet line means communicating with one of said hydraulic transmission lines when said control slide is in a first operative position; return line means communicating with the other one of said hydraulic transmission lines when said control slide is in a second operative position; control piston means movable within a control cylinder and actuating said control slide; electromagnetically actuated valves for applying working fluid to said control cylinder; remote control lever means for providing an adjustable input parameter; regulating amplifier means actuating said electromagnetic valves as a function of said input parameter; two flow lines communicating with said control cylinder and connected to said inlet line means and said return line means by two of said electromagnetically actuated valves; signal amplifying means connected to said electromagnetically actuated valves for actuating said electromagnetically actuated valves; and threshold switching means connected between said signal amplifying means and said regulating amplifying means.
Claim 3
Dependent Claim
49 words
The arrangement as defined in claim 1 wherein a first one of said electromagnetically actuated valves is connected between said inlet line means and said two electromagnetically actuated valves, said first one of said electromagnetically actuated valves being closed when said remote control lever means is in 0 position.
Claim 4
Dependent Claim
36 words
The arrangement as defined in claim 2 including a close control lever for actuating said control slide when said first one of said electromagnetically actuated valves is closed and said two electromagnetically actuated valves are open.
Claim 5
Dependent Claim
60 words
The arrangement as define in claim 2 including a dead center circuit; an input parameter transducer actuated by said remote control lever means; and a first amplifier in said signal amplifying means connected to said first one of said electromagnetically actuated valves, the input of said first amplifier being connected through said dead center circuit to said input parameter transducer.
Claim 6
Dependent Claim
60 words
The arrangement as defined in claim 4 wherein said dead center circuit comprises two threshold switching circuits having different threshold levels, the input of one threshold switching circuit being connected with a first input of the other threshold switching circuit, the output of said one threshold switching circuit being connected to a second input of the other threshold switching circuit.
Claim 7
Dependent Claim
48 words
The arrangement as defined in claim 4 inCluding AND-gates connected to a second amplifier and a third amplifier in said signal amplifying means; a threshold switching circuit connected to a first input of each AND-gate, the second inputs of said AND-gates being connected to said dead center circuit.
Claim 8
Dependent Claim
86 words
The arrangement as defined in claim 6 including an AND-gate connected to the input of said first amplifier, a first input of said AND-gate connected to said first amplifier being connected to said dead center circuit, said AND-gate connected in front of said first amplifier being a first AND-gate and said AND-gates connected to said second and third amplifiers being respectively second and third AND-gates; a fourth AND-gate connected between the second input of said first AND-gate and the outputs of said second and third AND-gates.
Claim 9
Dependent Claim
22 words
The arrangement as defined in claim 4 including an amplifying stage connected in series with the input of said dead center circuit.
Claim 10
Dependent Claim
55 words
The arrangement as defined in claim 1 including output parameter transducer means actuated by said control slide; input parameter transducer means actuated by said remote control lever means; and summing means with inputs connected to said input and output parameter transducer means, the output of said summing means being connected to said regulating amplifying means.
Claim 11
Dependent Claim
28 words
The arrangement as defined in claim 7 wherein said threshold switching circuits and said AND-gates are two-stage, positive feedback-coupled transistor amplifiers with two transistors of complementary conductivity type.
Claim 12
Dependent Claim
52 words
The arrangement as defined in claim 10 including base voltage divider means connected to a first one of said two transistors in said threshold switching circuits for setting the threshold voltage of said threshold switching circuit; and diode means for applying to the emitter of said first transistor the input voltage signal.
Claim 13
Dependent Claim
36 words
The arrangement as defined in claim 10 including diode means connected to the emitter of a first transistor of said AND-gates for applying input voltage signals to the emitter of said first transistor of said AND-gates.
Claim 14
Dependent Claim
92 words
The arrangement as defined in claim 4 including second and third AND-gates connected to second and third amplifiers in said amplifying means; and pulse stretcher modulator means connected to first inputs of said second and third AND-gates, the second inputs of said AND-gates being connected to said dead center circuit, said pulse stretcher modulator means controlling intermittently said electromagnetically actuated valves when the output signals of said regulating amplifier means are substantially small, said electromagnetically actuated valves being continuously unactuated when the output signals of said regulating amplifier means are substantially large.
Claim 15
Dependent Claim
82 words
The arrangement as defined in claim 13 wherein said pulse stretcher modulator comprises an operational amplifier with a first resistor connected between the output of said amplifier and one input thereof, and a second resistor connected between the output of said operational amplifier and a circuit input thereof; an input resistor connected to the inverting input of said operational amplifier, on terminal of said input resistor being the input signal terminal; and a capacitor connected between said input resistor and ground potential.
Claim 16
Dependent Claim
36 words
The arrangement as defined in claim 9 including a third threshold switch connected to the output of said output parameter transducer means; and a forth threshold switching circuit connected to the output of said summing means.
Claim 17
Dependent Claim
99 words
The arrangement as defined in claim 15 including a first OR-gate and a second OR-gate, the output of said third threshold switching circuit being connected to said second OR-gate and to said first OR-gate; a first inverter circuit connected between said output of said third threshold switching circuit and said first OR-gate; a second inverter circuit connected between the output of said fourth threshold switching cirCuit and said second OR-gate, the output of said fourth threshold switching circuit being also connected to said first OR-gate, the outputs of said OR-gates being connected to the inputs of said first AND-gate.
Claim 18
Dependent Claim
14 words
The arrangement as defined in claim 7 wherein said fourth AND-gate comprises a NAND-gate.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |