Patent US3767014A successfully refreshed from Google Patents.
US3767014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter system for crawler tractor final drives
Assignee: Fiat Allis Europe SpA
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Filing: 1972-05-26
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Granted: 1973-10-23
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Expires: 1992-05-26
Abstract
Abstract The lubricating fluid from one of a pair of final drive housings is routed through a filter during forward operation of the crawler tractor and the lubricating fluid from the other final drive housing is routed through the same filter during reverse operation of the crawler tractor. A unique automatic flow control valve and a reversible pump are so connected and arranged with the fluid filter and final drive housings so as to permit a single pump and a single filter to be employed in filtering the lubricating fluid in a pair of final drive housings without substantial interchange of lubricating fluid therebetween.
Inventors
- 👤 G Drone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:04
CPC Classifications
B; B62; B62D; B62D55/00; B62D55/08; B62D55/12; B62D55/125; F; F01; F01M; F01M9/00; F01M9/06; F16; F16N; F16N39/00; F16N39/06; F16N7/00; F16N7/38; F16N7/40
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
100 words
In a tractor having a pair of isolated transmission housings each of which contains lubricating fluid during normal tractor operation, the combination comprising: a fluid filter, fluid pumping means and fluid flow control means operatively associated with said fluid pumping means and filter, said flow control means having a first adjusted condition in which lubricating fluid from only one of said housings is routed through said filter and returned to said one housing and having a second adjusted condition in which lubricating fluid from the other of said housings is routed through said filter and returned to said other housing.
Claim 2
Dependent Claim
100 words
In a tractor having a pair of isolated transmission housings each of which contains lubricating fluid during normal tractor operation, the combination comprising: a fluid filter, fluid pumping means and fluid flow control means operatively associated with said fluid pumping means and filter, said flow control means having a first adjusted condition in which lubricating fluid from only one of said housings is routed through said filter and returned to said one housing and having a second adjusted condition in which lubricating fluid from the other of said housings is routed through said filter and returned to said other housing.
Claim 3
Dependent Claim
13 words
The invention of claim 1 wherein said pumping means is a reversible pump.
Claim 4
Dependent Claim
24 words
The invention of claim 2 wherein said pump is driven in opposite directions when said tractor is operated in forward and reverse directions, respectively.
Claim 5
Dependent Claim
68 words
The invention of claim 3 wherein said pump has a pair of ports connected to said fluid flow control means and said fluid flow control means includes a pair of conduits connected to said housings, respectively, for withdrawing fluid from said housings and a check valve operatively associated with each of said conduits permitting flow of lubricating fluid in said conduits from said housings and preventing reverse flow.
Claim 6
Dependent Claim
22 words
The invention of claim 4 wherein said flow control means includes an automatic flow control valve having a shiftable flow control element.
Claim 7
Dependent Claim
67 words
The invention of claim 5 wherein said flow control element is a valve spool and said control valve includes a housing having a bore in which said spool is reciprocably disposed between first and second axially shifted positions and having pressure chambers at each of the opposite ends of said bore, and wherein said ports of said pump are in fluid communication with said pressure chambers, respectively.
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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |