US3672402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic precharge adjuster
Assignee: Eaton Corp
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Filing: 1970-09-14
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Granted: 1972-06-27
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Expires: 1990-09-14
Abstract
Abstract An automatic precharge gas pressure adjuster for a hydraulic desurger for automatically adjusting the precharge gas pressure in response to operating changes in system fluid pressure thereby maintaining a constant volume of precharge gas in the desurger. The adjusting unit comprises a cylinder divided into two chambers by a spring-biased differential-area piston. The system fluid pressure communicates with the chamber facing the first or largest area piston face while precharge gas communicates with the chamber facing the second or smallest area piston face. To assure the precharge gas pressure will be adjusted for changes in system operating pressure only, and not for mere surges, snubbing restrictions are placed in the means connecting the hydraulic system with the precharge gas adjusting unit.
Inventors
- 👤 John W Bloemer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:41
CPC Classifications
F; F16; F16L; F16L55/00; F16L55/04; F16L55/045; F16L55/05; F16L55/052; F16L55/053; F15; F15B; F15B1/00; F15B1/02; F16L55/054
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
A control device for maintaining a substantially constant volume of precharge gas in a hydraulic device having two sections, the first of which is in communication with a variably pressurized hydraulic system and the second of which is filled with precharge gas at substantially the same pressure as the hydraulic system, said control device comprising: a piston having first and second opposed faces, said first face of greater surface area than said second face; a cylinder in which said piston is slidably and sealingly engaged, said piston dividing said cylinder into a first and second chamber faced by said first and second faces respectively, said first chamber exposed to hydraulic system pressure, said second chamber in communication with said second section and forming a closed variable volume precharge gas containing cavity therewith whereby changes in second chamber volume result in proportionally inverse changes in precharge gas pressure, and means biasing said piston towards said first chamber.
Claim 2
Dependent Claim
156 words
A control device for maintaining a substantially constant volume of precharge gas in a hydraulic device having two sections, the first of which is in communication with a variably pressurized hydraulic system and the second of which is filled with precharge gas at substantially the same pressure as the hydraulic system, said control device comprising: a piston having first and second opposed faces, said first face of greater surface area than said second face; a cylinder in which said piston is slidably and sealingly engaged, said piston dividing said cylinder into a first and second chamber faced by said first and second faces respectively, said first chamber exposed to hydraulic system pressure, said second chamber in communication with said second section and forming a closed variable volume precharge gas containing cavity therewith whereby changes in second chamber volume result in proportionally inverse changes in precharge gas pressure, and means biasing said piston towards said first chamber.
Claim 3
Dependent Claim
14 words
The control device of claim 1 wherein said hydraulic device is a hydraulic desurger.
Claim 4
Dependent Claim
14 words
The control device of claim 1 wherein said hydraulic device is a hydraulic accumulator.
Claim 5
Dependent Claim
61 words
The control device of claim 1 wherein said biasing means is a spring, the spring constant of said spring being such as to supply a force opposed and substantially equal to that force supplied by hydraulic system pressure, within the expected operating ranges, acting on that amount of surface area by which the first face is greater than the second face.
Claim 6
Dependent Claim
23 words
The device of claim 4 wherein said piston carries a stem variably extending from said cylinder in response to movements of said piston.
Claim 7
Dependent Claim
27 words
The automatic precharge adjuster of claim 4 wherein the operating characteristics of said desurger may be varied by varying the spring constant of said spring biasing means.
Claim 8
Dependent Claim
14 words
The device of claim 5 wherein said stem carries visual idica of system pressure.
Claim 9
Dependent Claim
32 words
The control device of claim 4 additionally comprising means communicating said first chamber with said hydraulic system, said communication means having a snubbing restriction between said first chamber and said hydraulic system.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |