US4451050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bi-directional hydrodynamic slitted seal
Assignee: Microdot Inc
•
Filing: 1983-05-16
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Granted: 1984-05-29
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Expires: 2003-05-16
Abstract
Abstract A polytetrafluoroethylene seal with intersecting arcuate slitted grooves to effect bi-directional hydrodynamic pumping of oil due to rotation of a shaft about which the seal is disposed.
Inventors
- 👤 James A. Repella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:04
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/32; F16J15/3244
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
98 words
A bi-directional hydrodynamic oil seal comprising an annular case, and a thin washer-like seal element having a radially outer portion supported by said case and a generally cylindrical radially inner portion adapted to engage a shaft, the radially inner portion of said seal element having a plurality of generally arcuate slits in the surface thereof that extend at an acute angle relative to the central axis of the shaft and divergent from the oil side of said seal and intersect the radially inner edge of said seal element to effect hydrodynamic pumping in conjunction with a rotating shaft.
Claim 2
Dependent Claim
98 words
A bi-directional hydrodynamic oil seal comprising an annular case, and a thin washer-like seal element having a radially outer portion supported by said case and a generally cylindrical radially inner portion adapted to engage a shaft, the radially inner portion of said seal element having a plurality of generally arcuate slits in the surface thereof that extend at an acute angle relative to the central axis of the shaft and divergent from the oil side of said seal and intersect the radially inner edge of said seal element to effect hydrodynamic pumping in conjunction with a rotating shaft.
Claim 3
Dependent Claim
27 words
A seal in accordance with claim 1, wherein the radius of said slits is less than the diameter of the shaft engaging portion of said seal element.
Claim 4
Dependent Claim
30 words
A seal in accordance with claim 2 wherein the edge of said slits farthest from the oil side of said seal is self-biased into full face contact with said shaft.
Claim 5
Dependent Claim
26 words
A seal in accordance with claim 1 wherein said arcuate slits intersect one another to define generally triangular pads engageable with the surface of the shaft.
Claim 6
Dependent Claim
47 words
A seal in accordance with claim 2 wherein the portions of said arcuate slits between said triangular pads define flex lines between said radially inner portion and an intermediate portion of said seal element thereby to facilitate deflection of said pads into full contact with a shaft.
Claim 7
Dependent Claim
82 words
A hydrodynamic oil seal comprising an annular case, and a thin washer-like seal element having a radially outer peripheral portion supported by said case and a generally cylindrical radially inner portion adapted to engage a shaft, the radially inner portion of said seal element having plurality of slits therein extending at an angle to the shaft engaging surface thereof to effect hydrodynamic pumping in conjunction with a rotating shaft, the adjacent walls of said slits being in close juxtaposed substantially parallel relation.
Claim 8
Dependent Claim
82 words
A hydrodynamic oil seal comprising an annular case, and a thin washer-like seal element having a radially outer peripheral portion supported by said case and a generally cylindrical radially inner portion adapted to engage a shaft, the radially inner portion of said seal element having plurality of slits therein extending at an angle to the shaft engaging surface thereof to effect hydrodynamic pumping in conjunction with a rotating shaft, the adjacent walls of said slits being in close juxtaposed substantially parallel relation.
Claim 9
Dependent Claim
30 words
A seal in accordance with claim 6 wherein said slits define flex lines that facilitate deflection of the radially inner portion of said seal element into contact with a shaft.
Claim 10
Dependent Claim
37 words
A seal in accordance with claim 7 wherein the circumferentially spaced portions of the radially inner portion of said seal element exhibit a relatively lower unit pressure against the shaft then adjacent portions of said seal element.
References Cited (Backward Citations)
GB492954A
Cited
US2606779A
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US3620540A
Cited
US3929341A
Cited
US4118856A
Cited
US4132421A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |