Patent US3575426A successfully refreshed from Google Patents.
US3575426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressurized sealing arrangement
Assignee: Caterpillar Inc
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Filing: 1968-06-24
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Granted: 1971-04-20
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Expires: 1988-06-24
Abstract
Abstract Two lip seal assemblies are coaxially mounted around a rotatable shaft to form a chamber therebetween adapted to be pressurized by air to lift the seals out of contact with the shaft. Thus, steady streams of air will flow past the seals to prevent oil or contaminants from moving in a direction opposite to such air flow.
Inventors
- 👤 Donald F Durham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:31
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/40; Y; Y10; Y10S; Y10S277/00; Y10S277/929
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
129 words
A pressurized sealing arrangement comprising a rotatable crankshaft, motive means for selectively rotating said crankshaft, at least one seal assembly mounted about said crankshaft and having a flexible lip normally contacting said shaft, normally closed chamber means formed on one side of said seal, and means for supplying pressurized air to said chamber means for flexing said lip, said flexible lip constructed to remain in full circumferential contact with said crankshaft when the pressure of said air falls below a predetermined level and to be continuously maintained only slightly out of contact with said crankshaft during rotation whereof when said air pressure exceeds said predetermined level to form an opening therebetween to continuously permit said pressurized air to flow therethrough to continuously prevent contaminants from entering said chamber means.
Claim 2
Dependent Claim
129 words
A pressurized sealing arrangement comprising a rotatable crankshaft, motive means for selectively rotating said crankshaft, at least one seal assembly mounted about said crankshaft and having a flexible lip normally contacting said shaft, normally closed chamber means formed on one side of said seal, and means for supplying pressurized air to said chamber means for flexing said lip, said flexible lip constructed to remain in full circumferential contact with said crankshaft when the pressure of said air falls below a predetermined level and to be continuously maintained only slightly out of contact with said crankshaft during rotation whereof when said air pressure exceeds said predetermined level to form an opening therebetween to continuously permit said pressurized air to flow therethrough to continuously prevent contaminants from entering said chamber means.
Claim 3
Dependent Claim
62 words
The invention of claim 1 further comprising means surrounding said seal disposed radially outwardly from said lip for normally maintaining said lip in contact with said crankshaft when said chamber means is not pressurized and said crankshaft is not rotating, said lip being V-shaped to form a line contact with said crankshaft positioned axially inwardly from an end of said seal assembly.
Claim 4
Dependent Claim
28 words
The invention of claim 1 wherein two of said seal assemblies are coaxially mounted about said crankshaft and spaced from each other to form said chamber means therebetween.
Claim 5
Dependent Claim
26 words
The invention of claim 1 wherein said motive means for selectively rotating said crankshaft simultaneously actuates said means for supplying pressurized air to saId chamber means.
Claim 6
Dependent Claim
24 words
The invention of claim 1 further comprising means for regulating and maintaining said pressurized air at a substantially constant level in said chamber means.
Claim 7
Dependent Claim
29 words
The invention of claim 1 wherein said crankshaft has a cylindrical collar secured thereto, said collar having a smooth surface formed on the periphery thereof normally contacting said lip.
Claim 8
Dependent Claim
18 words
The invention of claim 1 wherein said chamber means is formed at least in part by said seal.
Claim 9
Dependent Claim
58 words
The invention of claim 1 wherein said seal assembly further comprises a rubberlike seal having said lip formed as an integral part thereof and at least one annular retaining ring mechanically attached to said seal by means of a groove formed on radially outer circumferential portions of said seal to prevent axial movement thereof relative to said crankshaft.
References Cited (Backward Citations)
DE545243C
Cited
DE711737C
Cited
FR880243A
Cited
GB554331A
Cited
US3100105A
Cited
US3396979A
Cited
US3434727A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |