Patent US3918847A successfully refreshed from Google Patents.
US3918847A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Accumulator charging circuit for high pressure hydraulic system
Assignee: Caterpillar Inc
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Filing: 1974-02-06
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Granted: 1975-11-11
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Expires: 1994-02-06
Abstract
Abstract An accumulator charging arrangement for a high pressure hydraulic system. The arrangement includes a pair of relatively small volumetric capacity fixed-displacement pumps each of which is combined with a separate accumulator charging valve. The pumpcharging valve combinations are disposed in parallel to feed pressure fluid to a pair of accumulator devices for use of the hydraulic circuit upon specific demand. One pump-charging valve combination supplies pressure fluid only within a certain pressure range. The second pump-charging valve combination supplies fluid at a second discrete pressure range which is higher than that within which the first combination operates. For system demands within a lower pressure range, both pump-charging valve combinations are operative to supply fluid, however, upon a demand for pressure only within the higher pressure range, only the second pump-valve combination is operative to supply the separate accumulator devices associated with the combinations.
Inventors
- 👤 John A Junck
- 👤 Howard L Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:57
CPC Classifications
F; F04; F04B; F04B49/00; F04B49/22; F04B49/24; F15; F15B; F15B1/00; F15B1/02; F15B1/027; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/20576; F15B2211/70; F15B2211/71
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
399 words
An accumulator charging system for charging accumulator means which supply fluid under pressure to a fluid user circuit, said system comprising; accumulator means, a source of fluid, first pump means in fluid communication with said source, first fluid communication means for communicating the output of said first pump means with said accumulator means, said first pump means having a fixed displacement and maximum pumping capacity of a first predetermined value, first automatic charging valve means in said first fluid communication means for contorlling the flow of fluid from said first pump means to said accumulator means, said first automatic charging valve means being responsive to the pressure extant in said accumulator means for permitting fluid flow from said first pump means to said accumulator means only when the pressure within said accumulator means is within a first predetermined range of positive pressures and for returning fluid from said first pump means to said source when said accumulator means pressure is above said first predetermined range of pressures, second pump means in communication with said source, second fluid communication means for communicating the output of said second pump means with said accumulator means, second automatic charging valve means in said second fluid communication means for controlling the flow of fluid from said second pump means to said accumulator means, said second pump means having a fixed displacement and constant volumetric capacity of a given second predetermined value which is less than said first predetermined value, said second automatic charging valve means permitting fluid flow from said second pump means to said accumulator means when the pressure extant in said accumulator means is within a second predetermined range of positive pressures extending to a higher pressure than said first predetermined range of pressures, said second charging valve means being effective to return fluid from said second pump means to said source when accUmulator pressure rises above the maximum pressure of said second predetermined range of pressures, said accumulator means including first and second fluid accumulator devices each said accumulator device being connected for fluid communication with both of said first and second automatic charging valve means at least partially through common conduit means, first check valve means in said first fluid communication means between said common conduit means and said first accumulator device for permitting flow from said first charging valve means to said first accumulator device but preventing reverse flow.
Claim 2
Dependent Claim
399 words
An accumulator charging system for charging accumulator means which supply fluid under pressure to a fluid user circuit, said system comprising; accumulator means, a source of fluid, first pump means in fluid communication with said source, first fluid communication means for communicating the output of said first pump means with said accumulator means, said first pump means having a fixed displacement and maximum pumping capacity of a first predetermined value, first automatic charging valve means in said first fluid communication means for contorlling the flow of fluid from said first pump means to said accumulator means, said first automatic charging valve means being responsive to the pressure extant in said accumulator means for permitting fluid flow from said first pump means to said accumulator means only when the pressure within said accumulator means is within a first predetermined range of positive pressures and for returning fluid from said first pump means to said source when said accumulator means pressure is above said first predetermined range of pressures, second pump means in communication with said source, second fluid communication means for communicating the output of said second pump means with said accumulator means, second automatic charging valve means in said second fluid communication means for controlling the flow of fluid from said second pump means to said accumulator means, said second pump means having a fixed displacement and constant volumetric capacity of a given second predetermined value which is less than said first predetermined value, said second automatic charging valve means permitting fluid flow from said second pump means to said accumulator means when the pressure extant in said accumulator means is within a second predetermined range of positive pressures extending to a higher pressure than said first predetermined range of pressures, said second charging valve means being effective to return fluid from said second pump means to said source when accUmulator pressure rises above the maximum pressure of said second predetermined range of pressures, said accumulator means including first and second fluid accumulator devices each said accumulator device being connected for fluid communication with both of said first and second automatic charging valve means at least partially through common conduit means, first check valve means in said first fluid communication means between said common conduit means and said first accumulator device for permitting flow from said first charging valve means to said first accumulator device but preventing reverse flow.
Claim 3
Dependent Claim
44 words
The invention of claim 1 including second check valve means in said second fluid communication means between said common conduit means and said second accumulator device for permitting flow from said second charging valve means to said second accumulator device but preventing reverse flow.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |