US4352499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic pump with piston sealing
Assignee: Fletcher Sutcliffe Wild Ltd
•
Filing: 1979-11-28
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Granted: 1982-10-05
•
Expires: 1999-11-28
Abstract
Abstract A reciprocable piston hydraulic pump is provided with a piston periphery sealing means 24 comprising, at the pressure side, a seal 25 of flexible material and adapted to surround the piston periphery, a ring 27 separating the seal 25 from a moulded pressure seal, with a reservoir 28 defined between the seal 25 and the pressure seal, and spring means 29 operable on the seal 25 to urge the latter towards the pressure seal 26.
Inventors
- 👤 Malcolm C. Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:30
CPC Classifications
F; F04; F04B; F04B53/00; F04B53/16; F04B53/162; F04B53/164; F16; F16J; F16J15/00; F16J15/002; F16J15/006; Y; Y10; Y10S; Y10S277/00; Y10S277/935; Y10S277/944; Y10S277/945; Y10S277/946
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
72 words
A reciprocable piston hydraulic pump provided with a piston periphery sealing means comprising, at the pressure side, a first seal of flexible material surrounding said piston periphery, a second seal having a moulded pressure seal, a ring separating said first seal from said pressure seal, a reservoir defined between said first seal and said pressure seal, said spring means operable on said first seal to urge the latter towards said pressure seal.
Claim 2
Dependent Claim
72 words
A reciprocable piston hydraulic pump provided with a piston periphery sealing means comprising, at the pressure side, a first seal of flexible material surrounding said piston periphery, a second seal having a moulded pressure seal, a ring separating said first seal from said pressure seal, a reservoir defined between said first seal and said pressure seal, said spring means operable on said first seal to urge the latter towards said pressure seal.
Claim 3
Dependent Claim
15 words
A pump as claimed in claim 1, wherein said first seal is a rope seal.
Claim 4
Dependent Claim
27 words
A pump as claimed in claim 1, wherein said first seal is formed from a plurality of individual annular elements separated from one another by spacer washers.
Claim 5
Dependent Claim
14 words
A pump as claimed in claim 3, wherein said spacer washers are of P.T.F.E.
Claim 6
Dependent Claim
17 words
A pump as claimed in claim 1, wherein said spring means comprises a plurality of Belleville washers.
Claim 7
Dependent Claim
17 words
A pump as claimed in claim 1, wherein said reservoir is defined by a headed metallic ring.
Claim 8
Dependent Claim
15 words
A pump as claimed in claim 6, wherein said headed metallic ring is of bronze.
Claim 9
Dependent Claim
24 words
A pump as claimed in claim 1, comprising an annular seating recess carried in a ring, in which recess said pressure seal is seated.
Claim 10
Dependent Claim
13 words
A pump as claimed in claim 8, wherein said ring is of Monel.
Claim 11
Dependent Claim
19 words
A pump as claimed in claim 8, wherein said ring is provided with bearing liners to aid piston guidance.
Claim 12
Dependent Claim
16 words
A pump as claimed in claim 1, wherein said first seal is a natural fibre seal.
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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) | 1985-10-04 | 1986-04-05 | 1986-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-04 | 1990-04-05 | 1990-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-04 | 1994-04-05 | 1994-10-05 | $7700.00 | Window Closed / Lapsed |