US3801241A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pump impeller construction
Assignee: Micropump Inc
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Filing: 1973-02-08
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Granted: 1974-04-02
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Expires: 1993-02-08
Abstract
Abstract Gear pump impellers formed of Teflon because of the softness and slipperiness of the material are difficult to connect to a metallic shaft. Yet Teflon is a very good material for gear pump impellers because of its low co-efficient of friction, chemical inertness and ability to withstand high temperatures and extreme temperature variations. In this invention a portion of the plastic is confined between a rigid central shaft spline and a cup rotatable with the shaft so that the plastic cannot flow without two-dimensional or three-dimensional distortion or tearing, both of which are resisted by the plastic.
Inventors
- 👤 T Martin
- 👤 F Pieters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:36
CPC Classifications
F; F04; F04C; F04C15/00; F04C15/0057; F04C15/0076; F04C2/00; F04C2/08; F04C2/082; F04C2/084; F05; F05C; F05C2225/00; F05C2225/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316; Y10T29/49826; Y10T29/49833; Y10T29/49835; Y10T29/49861
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
112 words
A pump impeller comprising a rigid shaft having a noncircular portion, a blank of Teflon having a central bore shaped to fit over said non-circular portion with a tight fit, and at least one cup of rigid material having an annular end formed with an aperture to fit on the end of said shaft near said noncircular portion with a tight fit and having an inturned cylindrical flange having an inside diameter greater than said non-circular portion and an outside diameter substantially less than that of said blank, said flange forced into said blank from one end thereof, a portion of said blank being confined between said non-circular portion and said flange.
Claim 2
Dependent Claim
112 words
A pump impeller comprising a rigid shaft having a noncircular portion, a blank of Teflon having a central bore shaped to fit over said non-circular portion with a tight fit, and at least one cup of rigid material having an annular end formed with an aperture to fit on the end of said shaft near said noncircular portion with a tight fit and having an inturned cylindrical flange having an inside diameter greater than said non-circular portion and an outside diameter substantially less than that of said blank, said flange forced into said blank from one end thereof, a portion of said blank being confined between said non-circular portion and said flange.
Claim 3
Dependent Claim
21 words
An impeller according to claim 1 in which the edge of said cup is formed with serrations digging into said blank.
Claim 4
Dependent Claim
22 words
An impeller according to claim 1 in which said non-circular portion is hexagonal in cross-section and said flange is annular in cross-section.
Claim 5
Dependent Claim
18 words
An impeller according to claim 1 in which there is a cup on each end of said blank.
Claim 6
Dependent Claim
18 words
An impeller according to claim 1 in which said blank is formed with gear teeth on its periphery.
Claim 7
Independent Claim
103 words
A method of fabricating a gear blank and shaft combination comprising proviDing a shaft having a non-circular cross-section portion and round cross-section ends at either side of said non-circular portion, forcing an aperture blank of Teflon onto said non-circular portion, forcing over either of said ends a cup having an annular disk and inturned flanges so that said flanges are embedded in grooves formed in said blank of larger diameter than the size of said non-circular portion and some of the material of said blank is confined between said non-circular portion and said flanges and so that said cups rotate with said shaft.
Claim 8
Independent Claim
103 words
A method of fabricating a gear blank and shaft combination comprising proviDing a shaft having a non-circular cross-section portion and round cross-section ends at either side of said non-circular portion, forcing an aperture blank of Teflon onto said non-circular portion, forcing over either of said ends a cup having an annular disk and inturned flanges so that said flanges are embedded in grooves formed in said blank of larger diameter than the size of said non-circular portion and some of the material of said blank is confined between said non-circular portion and said flanges and so that said cups rotate with said shaft.
Claim 9
Dependent Claim
51 words
A method according to claim 6 which further comprises forming a depression in each end of said blank preliminary to forcing said blank on said shaft, each said depression being slightly smaller than the outside of the flange of said cup and of lesser depth than the length of said flange.
Claim 10
Dependent Claim
32 words
A method according to claim 6 which further comprises machining said blank to true outside diameter and cutting gear teeth in the blank after said cup has been embedded in said blank.
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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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |