US4313053A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Welding sleeve of thermoplastic material
Assignee: WAVIN AG
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Filing: 1980-01-02
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Granted: 1982-01-26
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Expires: 2000-01-02
Abstract
Abstract A sleeve member (4) formed from a pipe length by expansion is placed over a mandrel onto which are wound the spaced turns (7) of a resistance heating wire (6). By heating sleeve member (4) the latter is shrunk onto the turns (7). By electrically producing heat in wire (6) material flows around the expanding turns (7) and embed the latter completely in sleeve member (4), projecting material portions (8, 9) being formed in the vicinity of turns (7). Thus, a protection against electric shock hazard is obtained for turns (7) and after-working is made unnecessary for the standing back edge portions of inner wall (5) which deform inwards during manufacture.
Inventors
- 👤 Werner Sturm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:06
CPC Classifications
B; B29; B29D; B29D23/00; B29D23/001; B29D23/003; B29D23/005; B29C; B29C65/00; B29C65/02; B29C65/34; B29C65/3404; B29C65/342; B29C65/3472; B29C65/3476; B29C65/66; B29C65/68; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/50; B29C66/51; B29C66/52; B29C66/522; B29C66/5221; B29C66/5229; B29C65/3468
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
88 words
An electric welding muff for joining thermoplastic line elements, comprising a welding sleeve formed of a length of thermoplastic pipe having opposite axial ends and having an inner wall with an annular projection extending inwardly therefrom, said annular projection being spaced axially from said axial ends of said sleeve such that said sleeve has a greater internal diameter adjacent said axial ends than along said annular projection; and an electrical resistance heating wire arranged in a plurality of turns, said turns being entirely embedded in said annular projection.
Claim 2
Dependent Claim
88 words
An electric welding muff for joining thermoplastic line elements, comprising a welding sleeve formed of a length of thermoplastic pipe having opposite axial ends and having an inner wall with an annular projection extending inwardly therefrom, said annular projection being spaced axially from said axial ends of said sleeve such that said sleeve has a greater internal diameter adjacent said axial ends than along said annular projection; and an electrical resistance heating wire arranged in a plurality of turns, said turns being entirely embedded in said annular projection.
Claim 3
Dependent Claim
27 words
An electric welding muff according to claim 1, wherein said projection is formed from thermoplastic material applied to said sleeve inner wall with said heating wire turns.
Claim 4
Dependent Claim
20 words
An electric welding muff according to claim 2, wherein said projection extends at least 0.1 mm. from said inner wall.
Claim 5
Dependent Claim
23 words
An electric welding muff according to claim 1, wherein said projection is formed as a unitary portion of said length of thermoplastic pipe.
Claim 6
Dependent Claim
20 words
An electric welding muff according to claim 4, wherein said projection extends at least 0.1 mm. from said inner wall.
Claim 7
Dependent Claim
20 words
An electric welding muff according to claim 1, wherein said projection extends at least 0.1 mm. from said inner wall.
Claim 8
Dependent Claim
23 words
An electric welding muff according to claim 1, wherein said heating wire turns are covered by a 0.5 mm. thickness of thermoplastic material.
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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) | 1985-01-25 | 1985-07-27 | 1986-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-25 | 1989-07-27 | 1990-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-25 | 1993-07-27 | 1994-01-26 | $7700.00 | Window Closed / Lapsed |