US3776665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two stage fluid pump
Assignee: Westran Corp
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Filing: 1971-07-08
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Granted: 1973-12-04
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Expires: 1991-07-08
Abstract
Abstract A fluid pump having a reciprocally mounted air driven piston including portions extending from opposite sides thereof with each piston portion extending into a pair of axially spaced pressure chambers such that when the air piston is reciprocated in one direction within the housing the piston portion at one end is in a compression stroke and compresses its associated chambers to discharge pressure fluid from the pump through an appropriate outlet portion, while the portion at the opposite end of the air piston is in an expansion stroke and expands its associated chambers to draw fluid therein from a reservoir. One pressure chamber associated with each of the piston portions has a valve means adapted to exhaust fluid pressure therein while closing communication with its associated chamber when the pressure in the same reaches a predetermined value. Actuation of the valve means is accomplished by an actuating mechanism responsive to a predetermined pressure build up as caused by the load being imposed upon the fluid user such that in the absence of a predetermined pressure being produced by the fluid user during each compression stroke fluid is discharged from the pump from both chambers at a first, relatively high, rate of flow and at a pressure less than the predetermined pressure, and upon the predetermined pressure being reached the spaced pressure chambers are fluidly disconnected, resulting in a decreased rate of fluid flow from the pump, while the pressure of the discharged fluid is increased. Valve means are provided to control the direction of flow of the fluid discharged from the pressure chambers on opposite sides of the air piston to either direct the fluid from each side of the pump to a single fluid user or to provide two sources of pressure fluid for separate fluid users.
Inventors
- 👤 T Dalton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:21
CPC Classifications
F; F03; F03C; F03C1/00; F03C1/08; F03C1/14; F04; F04B; F04B49/00; F04B49/007; F04B5/00; F04B9/00; F04B9/08; F04B9/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
402 words
A fluid pump adapted to be driven by a pressurized fluid, said fluid pump comprising: a housing having a bore separated on opposite sides into first and second, cylindrically formed, axially spaced pressure chambers, said first pressure chambers being of a larger diameter than said second pressure chambers; piston means carried in said bore and having cylindrical portions at each end extending into said first and second chambers, the portions of said piston means extending into said second chambers being of a smaller diameter than the portions of said piston means extending into said first chambers; means for reciprocating said piston means; a first port means for each of said first pressure chambers and respectively communicating said first pressure chambers to a source of fluid; a second port means for respectively exhausting said first pressure chambers; valve means normally closing communication between said first pressure chambers and their associated second port means; outlet port means communicating with said first and second pressure chambers; means responsive to a predetermined outlet pressure to actuate said valve means to open communication between said first chambers and said second port whereby fluid in said first chamber is exhausted through said second port means and fluid is thereaFter delivered to said outlet port means only from said second pressure chambers; said means for reciprocating said piston means comprising a piston having a pressure responsive area substantially exceeding the effective area of each of the portions of said piston means said piston and said piston means being reciprocally mounted in said housing on a coextensive axis, means for automatically supplying the pressurized gas to opposite sides of said piston to reciprocate said piston means; said last mentioned means comprising a source of pressurized air; a shuttle valve connected with said source of pressurized gas and operable in a first position to direct pressurized gas to one side of said piston and to exhaust the opposite side of said piston, and in a second position to exhaust said first mentioned side of said piston and to direct pressurized gas to the opposite of said piston; valve means automatically moving said shuttle valve between said first position and said second position to automatically reciprocate said piston; said valve means comprising means delivering pressurized gas from the sides of said piston to the ends of said shuttle valve in response to said piston being moved to limit positions in each direction.
Claim 2
Dependent Claim
402 words
A fluid pump adapted to be driven by a pressurized fluid, said fluid pump comprising: a housing having a bore separated on opposite sides into first and second, cylindrically formed, axially spaced pressure chambers, said first pressure chambers being of a larger diameter than said second pressure chambers; piston means carried in said bore and having cylindrical portions at each end extending into said first and second chambers, the portions of said piston means extending into said second chambers being of a smaller diameter than the portions of said piston means extending into said first chambers; means for reciprocating said piston means; a first port means for each of said first pressure chambers and respectively communicating said first pressure chambers to a source of fluid; a second port means for respectively exhausting said first pressure chambers; valve means normally closing communication between said first pressure chambers and their associated second port means; outlet port means communicating with said first and second pressure chambers; means responsive to a predetermined outlet pressure to actuate said valve means to open communication between said first chambers and said second port whereby fluid in said first chamber is exhausted through said second port means and fluid is thereaFter delivered to said outlet port means only from said second pressure chambers; said means for reciprocating said piston means comprising a piston having a pressure responsive area substantially exceeding the effective area of each of the portions of said piston means said piston and said piston means being reciprocally mounted in said housing on a coextensive axis, means for automatically supplying the pressurized gas to opposite sides of said piston to reciprocate said piston means; said last mentioned means comprising a source of pressurized air; a shuttle valve connected with said source of pressurized gas and operable in a first position to direct pressurized gas to one side of said piston and to exhaust the opposite side of said piston, and in a second position to exhaust said first mentioned side of said piston and to direct pressurized gas to the opposite of said piston; valve means automatically moving said shuttle valve between said first position and said second position to automatically reciprocate said piston; said valve means comprising means delivering pressurized gas from the sides of said piston to the ends of said shuttle valve in response to said piston being moved to limit positions in each direction.
Claim 3
Dependent Claim
129 words
The pump defined in claim 1 wherein said valve means comprises: a bore in said housing communicating said first pressure chamber with said exhaust port means, a valve seat formed at one end of said bore; a valve member resiliently biased into engagement with said seat to normally close communication from said first pressure chamber through said bore passageway; said actuating means comprises: a second bore in said housing having a rod slidably mounted therein; said rod projecting toward said valve means; means communicating the pressure fluid within said second pressure chamber to the end of said rod whereby said rod engages said second valve member to unseat the same when the pressure in said second pressure chamber exceeds said predetermined amount to thereby exhaust said first pressure chamber.
Claim 4
Dependent Claim
29 words
The pump defined in claim 1 wherein the effective area of said first piston exposed to said first pressure chamber substantially exceeds the effective area of said second piston.
Claim 5
Dependent Claim
47 words
The pump defined in claim 1 wherein the ratio of the effective area of the portions of said piston means extending into said first pressure chamber to the effective area of the portions of said piston means extending into said second pressure chamber is at least 80:1.
Claim 6
Dependent Claim
19 words
The pump defined in claim 1 wherein said second piston is a coaxial integral extension of said first piston.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |