US4451413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Jacketing steel tubes and pipes
Assignee: Vodafone GmbH
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Filing: 1981-12-07
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Granted: 1984-05-29
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Expires: 2001-12-07
Abstract
Abstract A steel pipe is jacketed by concurrent extrusion of an ethylene hose concentric with a copolymer hose serving as an adhesive, the pipe passing through the extruder heat at an approximately 10% higher speed. The copolymer is predried, and the pipe is preferably precoated with heat-curable phenol or epoxy.
Inventors
- 👤 Walter Stucke
- 👤 Karl-Heinz Glissmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:38
CPC Classifications
B; B29; B29B; B29B13/00; B29B13/06; B29B13/065; B29C; B29C48/00; B29C48/15; B29C48/151; B29C48/03; B29C48/09; B29C48/16; B29C48/18; B29C48/21; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2705/00; B29K2705/08; B29K2705/12; B29K2995/00; B29K2995/0037; B29K2995/0072; B29L; B29L2009/00; B29L2009/003; B29L2023/00; B29L2023/22
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
148 words
A method of jacketing a steel pipe by means of a dual nozzle extruding device, wherein an inner hose is extruded of a granulated ethylene copolymer to act as an adhesive, and an outer hose of a thermoplastic is extruded as the jacket proper, the improvement comprising said copolymer including acrylic acid and acrylic acid ester pre-drying the copolymer in air having a dew point below -30° C. at a temperature of about 70° C. and for approximately one hour the thermoplastic and the copolymer, being extruded at the same speed at a temperature between 140° C. and 170° C., the speed being selected to be the higher, the higher the temperature of the thermoplastic and the copolymer in the dual nozzle head, accordingly the speed being at least 5 cm/sec. for a 140° C. head temperature, and at least 10 cm/sec. for a 175° C. head temperature.
Claim 2
Independent Claim
148 words
A method of jacketing a steel pipe by means of a dual nozzle extruding device, wherein an inner hose is extruded of a granulated ethylene copolymer to act as an adhesive, and an outer hose of a thermoplastic is extruded as the jacket proper, the improvement comprising said copolymer including acrylic acid and acrylic acid ester pre-drying the copolymer in air having a dew point below -30° C. at a temperature of about 70° C. and for approximately one hour the thermoplastic and the copolymer, being extruded at the same speed at a temperature between 140° C. and 170° C., the speed being selected to be the higher, the higher the temperature of the thermoplastic and the copolymer in the dual nozzle head, accordingly the speed being at least 5 cm/sec. for a 140° C. head temperature, and at least 10 cm/sec. for a 175° C. head temperature.
Claim 3
Dependent Claim
20 words
The method as in claim 1, wherein the speed of the pipe being jacketed is 10% above said flow speed.
Claim 4
Dependent Claim
40 words
The method as in claim 1, and including the step of coating the pipe, prior to jacketing, with a thermosetting resin, heating the pipe prior to jacketing same to above 100° C. and subsequent to jacketing to approximately 200° C.
Claim 5
Dependent Claim
12 words
The method as in claim 3, said heating being carried out inductively.
References Cited (Backward Citations)
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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) | 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 |