Patent US4545947A successfully refreshed from Google Patents.
US4545947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of strengthening polypropylene hose
Assignee: Whirlpool Corp
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Filing: 1983-12-02
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Granted: 1985-10-08
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Expires: 2003-12-02
Abstract
Abstract A method of treating polypropylene hose to increase its strength and durability is provided by flexing the hose through a plurality of 360 degree rotations while in a bent form to alternately axially compress and extend portions of the hose to increase the molecular alignment of the polypropylene.
Inventors
- 👤 David B. Bozoarth
- 👤 William R. Rickel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:08
CPC Classifications
B; B29; B29C; B29C31/00; B29C31/002; B29C71/00; B29C71/0072; B29K; B29K2023/00; B29K2023/10; B29K2023/12; B29K2995/00; B29K2995/0037; B29K2995/0082; B29L; B29L2023/00; B29L2023/18
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
57 words
The method of enhancing the molecular alignment of polypropylene hose comprising the steps: extruding polypropylene into a hose shape at an elevated temperature, forming corrugation in the hose, advancing said hose through a bend, and relatively rotating said hose or said bend through a plurality of 360 degree rotations while continuously advancing said hose through said bend.
Claim 2
Independent Claim
57 words
The method of enhancing the molecular alignment of polypropylene hose comprising the steps: extruding polypropylene into a hose shape at an elevated temperature, forming corrugation in the hose, advancing said hose through a bend, and relatively rotating said hose or said bend through a plurality of 360 degree rotations while continuously advancing said hose through said bend.
Claim 3
Dependent Claim
18 words
The method of claim 1, including the step of cutting said hose to length prior to flexing it.
Claim 4
Dependent Claim
25 words
The method of claim 2 wherein said step of relatively rotating said hose in said bend comprises rotating said hose in a fixed bend guide.
Claim 5
Dependent Claim
17 words
The method of claim 1, including the step of cutting said hose to length after flexing it.
Claim 6
Dependent Claim
42 words
The method of claim 4 wherein said step of relatively rotating said hose or said bend comprises the steps of securing portions of said hose on opposite sides of said bend against rotation and rotating said bend through said 360 degree rotations.
Claim 7
Independent Claim
16 words
The method of 1, wherein said bend is at an angle of at least 90 degrees.
Claim 8
Independent Claim
16 words
The method of 1, wherein said bend is at an angle of at least 90 degrees.
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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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |