US5209152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Airfoil changeover device
Assignee: Graco Inc
•
Filing: 1992-03-31
•
Granted: 1993-05-11
•
Expires: 2012-03-31
Abstract
Abstract An air operated reciprocating piston pump having a differential area piston is provided with an annular shaped airfoil device having a chevron cross-section and which is located beneath the bottom air intake plate to utilize increasing air velocity at the initiation of bottom changeover in order to assure more reliable changeover.
Inventors
- 👤 Andrew M. Olson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:19
CPC Classifications
F; F01; F01L; F01L21/00; F01L21/04; F04; F04B; F04B9/00; F04B9/08; F04B9/12; F04B9/123; F04B9/125; F04B9/1253
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
118 words
In an air-operated reciprocating piston pump having a hollow center displacement rod comprising a top end with a piston located about said top end and a valve assembly comprising top and bottom air intake plates located above and below said piston respectively, said intake plates being attached to each other by spacers passing through a plurality of circumferentially spaced air passages in said piston, the improvement comprising means for increasing and utilizing air velocity during bottom changeover to increase axial changeover force and reliability, said velocity increasing means comprising an annular airfoil comprising a chevron cross-section with a base facing axially downward and an apex facing axially upward, said airfoil being located beneath said bottom air intake plate.
Claim 2
Dependent Claim
118 words
In an air-operated reciprocating piston pump having a hollow center displacement rod comprising a top end with a piston located about said top end and a valve assembly comprising top and bottom air intake plates located above and below said piston respectively, said intake plates being attached to each other by spacers passing through a plurality of circumferentially spaced air passages in said piston, the improvement comprising means for increasing and utilizing air velocity during bottom changeover to increase axial changeover force and reliability, said velocity increasing means comprising an annular airfoil comprising a chevron cross-section with a base facing axially downward and an apex facing axially upward, said airfoil being located beneath said bottom air intake plate.
Claim 3
Dependent Claim
12 words
The pump of claim 1 wherein said airfoil is comprised of polytetrafluoroethylene.
References Cited (Backward Citations)
US943829A
Cited
US1965064A
Cited
US2773483A
Cited
US2846190A
Cited
US3094938A
Cited
US4028014A
Cited
US4214854A
Cited
US4397614A
Cited
US4780065A
Cited
US4821555A
Cited
US4879943A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-10 | 1996-11-09 | 1997-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-10 | 2000-11-09 | 2001-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-10 | 2004-11-09 | 2005-05-11 | $7700.00 | Window Closed / Lapsed |