US4080979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined summing and underspeed valve
Assignee: Caterpillar Inc
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Filing: 1977-03-22
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Granted: 1978-03-28
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Expires: 1997-03-22
Abstract
Abstract A combined summing and underspeed valve including a valve body having a bore, a spool within the bore, an outlet from the bore in the body intermediate the ends of the bore, a pair of spaced inlets in the bore for receiving fluid under pressure to apply force to opposite ends of the spool, at least two additional inlets in the body for receiving fluid under pressure to apply force to one of the ends of the spool, and pistons for isolating fluid from the inlet of the pair applying force to the spool one end from fluid from the additional inlets while applying force to the spool.
Inventors
- 👤 Allyn J. Hein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:02
CPC Classifications
F; F04; F04B; F04B49/00; F04B49/002; F04B49/007; F04B49/10; F04B49/103; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/265
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
A combined summing and underspeed valve comprising: a valve body having a bore; a spool within said bore; an outlet from said bore in said body intermediate the ends of said bore; a pair of spaced inlets in said bore for receiving fluid under pressure to apply force to opposite ends of said spool; at least two additional inlets in said body for receiving fluid under pressure to apply force to one of said ends of said spool; and means for isolating fluid from the inlet of said pair applying force to said spool one end from fluid from said additional inlets.
Claim 2
Dependent Claim
102 words
A combined summing and underspeed valve comprising: a valve body having a bore; a spool within said bore; an outlet from said bore in said body intermediate the ends of said bore; a pair of spaced inlets in said bore for receiving fluid under pressure to apply force to opposite ends of said spool; at least two additional inlets in said body for receiving fluid under pressure to apply force to one of said ends of said spool; and means for isolating fluid from the inlet of said pair applying force to said spool one end from fluid from said additional inlets.
Claim 3
Dependent Claim
26 words
The valve of claim 1 wherein said isolating means comprise a plurality of pistons, one for each additional inlet, in engagement with said spool one end.
Claim 4
Dependent Claim
28 words
The valve of claim 1 further including a feedback conduit in said body extending from said outlet to the end of said bore adjacent said spool one end.
Claim 5
Dependent Claim
13 words
The valve of claim 3 further including a flow restriction in said conduit.
Claim 6
Dependent Claim
24 words
The valve of claim 1 including a conduit in said body interconnecting the inlets of said pair, and a flow restriction in said conduit.
Claim 7
Dependent Claim
26 words
The valve of claim 5 including an additional conduit within said body and connected in parallel with said conduit and having a variable flow restriction therein.
Claim 8
Dependent Claim
117 words
A combined summing and underspeed valve comprising: a valve body having a bore; a spool within said bore; an outlet from said bore in said body intermediate the ends of said bore; a pair of spaced inlets in said bore for receiving fluid under pressure to apply force to opposite ends of said spool; one of said inlets extending to a groove in said spool for allowing fluid flow from said one inlet to said outlet, said spool further including a conduit extending from said groove to one end of the spool and opening thereat; and at least two additional inlets in said body for receiving fluid under pressure and having pistons engaging said spool one end.
Claim 9
Dependent Claim
117 words
A combined summing and underspeed valve comprising: a valve body having a bore; a spool within said bore; an outlet from said bore in said body intermediate the ends of said bore; a pair of spaced inlets in said bore for receiving fluid under pressure to apply force to opposite ends of said spool; one of said inlets extending to a groove in said spool for allowing fluid flow from said one inlet to said outlet, said spool further including a conduit extending from said groove to one end of the spool and opening thereat; and at least two additional inlets in said body for receiving fluid under pressure and having pistons engaging said spool one end.
Claim 10
Dependent Claim
18 words
The valve of claim 7 wherein the other end of the spool is abutted by a biasing spring.
Claim 11
Dependent Claim
54 words
The valve of claim 7 wherein the other end of said spool includes a bore, a piston slidable within said spool bore, a spring interposed between said spool and the slidable piston within the bore, and a conduit extending from said outlet to the bore in said valve body adjacent said spool other end.
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) | 1981-03-27 | 1981-09-26 | 1982-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-27 | 1985-09-26 | 1986-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-27 | 1989-09-26 | 1990-03-28 | $7700.00 | Window Closed / Lapsed |