US4191018A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid transmission
Assignee: Individual
•
Filing: 1978-04-28
•
Granted: 1980-03-04
•
Expires: 1998-04-28
Abstract
Abstract A fluid transmission which includes a hydraulic pump combination and a hydraulic motor. The hydraulic pump combination includes a first pump which is a variable volume, variable direction pump and a second pump which is a constant volume, constant direction pump. The combined outputs of the first and second pumps are directed to a hydraulic motor at variable rates and in reversible directions.
Inventors
- 👤 George M. Barrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:02
CPC Classifications
F; F16; F16H; F16H39/00; F16H39/02; F16H61/00; F16H61/38; F16H61/40; F16H61/42; F16H61/44; F16H61/448
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
67 words
A hydraulic pump combination for supplying hydraulic fluid under pressure to a hydraulic motor at variable rates and in reversible directions, said pump combination comprising first and second pumps constantly directly connected in parallel in fixed relation to first and second lines for a hydraulic motor, said first pump being a variable volume, variable direction pump, and said second pump being a constant volume, constant direction pump.
Claim 2
Dependent Claim
67 words
A hydraulic pump combination for supplying hydraulic fluid under pressure to a hydraulic motor at variable rates and in reversible directions, said pump combination comprising first and second pumps constantly directly connected in parallel in fixed relation to first and second lines for a hydraulic motor, said first pump being a variable volume, variable direction pump, and said second pump being a constant volume, constant direction pump.
Claim 3
Dependent Claim
21 words
The pump combination of claim 1 wherein said second pump volume is less than the maximum volume of said first pump.
Claim 4
Dependent Claim
46 words
The pump combination of claim 2 wherein the ratio of said second pump volume to said first pump maximum volume is on the order of 1 to 2 with the forward output volume to the reverse output volume being on the order of 3 to 1.
Claim 5
Dependent Claim
47 words
The pump combination of claim 2 wherein the output of said second pump is always positive, and the combined output of said pump combination is zero when the output of said first pump is equal to the output of said second pump but in a reverse position.
Claim 6
Dependent Claim
30 words
The pump combination of claim 1 together with a hydraulic motor connected to said first and second lines in fixed relationship, said pumps and said motor forming a hydraulic transmission.
Claim 7
Dependent Claim
22 words
The combination of claim 5 wherein said pumps have drive shafts, and means connecting said drive shafts together for constant relative rotation.
Claim 8
Dependent Claim
20 words
The combination of claim 5 wherein said second pump volume is less than the maximum volume of said first pump.
Claim 9
Dependent Claim
45 words
The combination of claim 7 wherein the ratio of said second pump volume to said first pump maximum volume is on the order of 1 to 2 with the forward output volume to the reverse output volume being on the order of 3 to 1.
Claim 10
Dependent Claim
46 words
The combination of claim 7 wherein the output of said second pump is always positive, and the combined output of said pump combination is zero when the output of said first pump is equal to the output of said second pump but in a reverse direction.
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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) | 1983-03-04 | 1983-09-03 | 1984-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-04 | 1987-09-03 | 1988-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-04 | 1991-09-03 | 1992-03-04 | $7700.00 | Window Closed / Lapsed |