US3726307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure control apparatus
Assignee: Cooper Industries LLC
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Filing: 1971-12-09
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Granted: 1973-04-10
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Expires: 1991-12-09
Abstract
Abstract Control apparatus is disclosed for regulating fluid pressure in a fluid system between predetermined lower and upper limits of such pressure by comparing electrical voltages proportional to the fluid pressure in said system and to said lower and upper limits of pressure. Electrical control signals are generated in response to differences in the compared voltages to actuate solenoid operated valves connected in the fluid system for increasing the fluid pressure in the system when below said lower limit, and decreasing said fluid pressure when above said upper limit. The specific embodiment of the control system described is connected to control the pilot pressure of a pilot operated hydraulic pressure regulator.
Inventors
- 👤 R Carman
- 👤 P Benson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:01
CPC Classifications
G; G05; G05D; G05D16/00; G05D16/20; G05D16/2006; G05D16/2013; G05D16/2026; G05D16/2046; G05D16/2053; G05D16/2093; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7761
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
205 words
Control apparatus for maintaining fluid pressure in a fluid system substantially within lower and upper limits of such pressure wherein such a fluid system includes pressure control means responsive to a first electrical control signal to increase pressure in said system and to a second electrical control signal to decrease pressure in said system, said apparatus comprising, in combination: pressure transducer means adapted to respond to fluid pressure in such a system to provide a first electrical signal proportional thereto; first electrical circuit means for providing a first reference electrical signal that is proportional to substantially said lower limit of fluid pressure; second electrical circuit means for providing a second reference electrical signal that is proportional to substantially said upper limit of fluid pressure; and comparator circuit mEans connected to said pressure transducer means and said first and second electrical circuit means and responsive to a difference between said first reference signal and said first electrical signal to provide said first electrical control signal when said fluid pressure is below said lower limit, and responsive to a difference between said second reference electrical signal and said first electrical signal to provide said second electrical control signal when said fluid pressure is above said upper limit.
Claim 2
Dependent Claim
205 words
Control apparatus for maintaining fluid pressure in a fluid system substantially within lower and upper limits of such pressure wherein such a fluid system includes pressure control means responsive to a first electrical control signal to increase pressure in said system and to a second electrical control signal to decrease pressure in said system, said apparatus comprising, in combination: pressure transducer means adapted to respond to fluid pressure in such a system to provide a first electrical signal proportional thereto; first electrical circuit means for providing a first reference electrical signal that is proportional to substantially said lower limit of fluid pressure; second electrical circuit means for providing a second reference electrical signal that is proportional to substantially said upper limit of fluid pressure; and comparator circuit mEans connected to said pressure transducer means and said first and second electrical circuit means and responsive to a difference between said first reference signal and said first electrical signal to provide said first electrical control signal when said fluid pressure is below said lower limit, and responsive to a difference between said second reference electrical signal and said first electrical signal to provide said second electrical control signal when said fluid pressure is above said upper limit.
Claim 3
Dependent Claim
59 words
The apparatus of claim 1 wherein said comparator circuit means includes a lower level comparator circuit responsive to said first electrical signal and said first reference signal to provide said first electrical control signal, and an upper level comparator circuit responsive to said first electrical signal and said second reference electrical signal to provide said second electrical control signal.
Claim 4
Dependent Claim
83 words
The apparatus of claim 1 wherein said first reference electrical signal is a first voltage substantially proportional in amplitude to said lower limit of pressure, and said second reference electrical signal comprises said first voltage plus a second voltage substantially proportional in amplitude to the pressure difference between said lower and upper limits, and wherein said second electrical circuit means includes a linear adder circuit connected to said first electrical circuit means and responsive to said first voltage to provide said second voltage.
Claim 5
Dependent Claim
83 words
The apparatus of claim 2 wherein said first reference electrical signal is a first voltage substantially proportional in amplitude to said lower limit of pressure, and said second reference electrical signal comprises said first voltage plus a second voltage substantially proportional in amplitude to the pressure difference between said lower and upper limits, and wherein said second electrical circuit means includes a linear adder circuit connected to said first electrical circuit means and responsive to said first voltage to provide said second voltage.
Claim 6
Dependent Claim
31 words
The apparatus of claim 1 further including means for inhibiting operation of said control apparatus when pressure changes occur in said fluid system at a rate greater than a predetermined frequency.
Claim 7
Dependent Claim
17 words
The apparatus of claim 5 wherein said last mentioned means is provided by said pressure transducer means.
Claim 8
Dependent Claim
16 words
The apparatus of claim 5 wherein said last mentioned means is a lower pass filter circuit.
Claim 9
Dependent Claim
31 words
The apparatus of claim 2 wherein each of said lower and upper level comparators includes means for providing a controlled amount of hysteresis about said lower and upper limits of pressure.
Claim 10
Dependent Claim
214 words
In combination with a fluid system including pressure control means responsive to a first electrical control signal to increase fluid pressure in said fluid system, and responsive to a second electrical control signal to decrease fluid pressure in said system, control apparatus for providing said first and second electrical control signals to maintain said pressure substantially within lower and upper limits of such pressure, said control apparatus comprising; pressure transducer means adapted to respond to fluid pressure in such a system to provide a first electrical signal proportional thereto; first electrical circuit means for providing a first reference electrical signal that is proportional to substantially said lower limit of fluid pressure; said electrical circuit means for providing a second reference electrical signal that is proportional to substantially said upper limit of fluid pressure; and comparator circuit means connected to said pressure transducer means and said first and second electrical circuit means and responsive to a difference between said first reference signal and said first electrical signal to provide said first electrical control signal when said fluid pressure is below said lower limit, and responsive to a difference between said second reference electrical signal and said first electrical signal to provide said second electricAl control signal when said fluid pressure is above said upper limit
Claim 11
Dependent Claim
214 words
In combination with a fluid system including pressure control means responsive to a first electrical control signal to increase fluid pressure in said fluid system, and responsive to a second electrical control signal to decrease fluid pressure in said system, control apparatus for providing said first and second electrical control signals to maintain said pressure substantially within lower and upper limits of such pressure, said control apparatus comprising; pressure transducer means adapted to respond to fluid pressure in such a system to provide a first electrical signal proportional thereto; first electrical circuit means for providing a first reference electrical signal that is proportional to substantially said lower limit of fluid pressure; said electrical circuit means for providing a second reference electrical signal that is proportional to substantially said upper limit of fluid pressure; and comparator circuit means connected to said pressure transducer means and said first and second electrical circuit means and responsive to a difference between said first reference signal and said first electrical signal to provide said first electrical control signal when said fluid pressure is below said lower limit, and responsive to a difference between said second reference electrical signal and said first electrical signal to provide said second electricAl control signal when said fluid pressure is above said upper limit
Claim 12
Dependent Claim
59 words
The system of claim 1 wherein said comparator circuit means includes a lower level comparator circuit responsive to said first electrical signal and said first reference signal to provide said first electrical control signal, and an upper level comparator circuit responsive to said first electrical signal and said second reference electrical signal to provide said second electrical control signal.
Claim 13
Dependent Claim
80 words
The system of claim 9 wherein said pressure control means includes a lower level solenoid controlled valve adapted to be connected between said fluid system and a source of fluid pressure and responsive to said first electrical control signal to add fluid pressure to said fluid system, and an upper level solenoid valve adapted to be connected between said fluid system and a drain and responsive to said second electrical control signal to remove fluid pressure from said fluid system.
Claim 14
Dependent Claim
30 words
The system of claim 9 wherein said fluid system further includes a pilot operated pressure regulator and the fluid pressure to be regulated is the pilot pressure of said regulator.
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) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |