Patent US3954541A successfully refreshed from Google Patents.
US3954541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Welding of thermoplastics through resistance heating
Assignee: Vodafone GmbH
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Filing: 1974-09-23
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Granted: 1976-05-04
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Expires: 1994-09-23
Abstract
Abstract Surfaces of thermoplastic parts are welded by placing a star-shaped heating element in-between the parts. The element is a coiled wire jacketed in plastic which melts during the welding. The resulting bond covers a relatively large area. The method is used for providing a saddle flange to a thermoplastic tube.
Inventors
- 👤 Helmut Landgraf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:42
CPC Classifications
B; B29; B29C; B29C66/00; B29C66/50; B29C66/51; B29C66/52; B29C66/522; B29C66/5224; B29C66/52241; B29C65/00; B29C65/02; B29C65/34; B29C65/36; B29C65/3604; B29C65/362; B29C65/3628; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/13; B29C66/131; B29C66/5229; B29C66/52298; B29C66/80; B29C66/83; B29C66/832; B29C66/8322; F; F16; F16L; F16L47/00; F16L47/02; F16L47/03; H; H05; H05B; H05B3/00; H05B3/40; H05B3/54; H05B3/58
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
164 words
The method of welding thermoplastic parts whereby an areal bond is to be made between surface portions of the parts comprising: providing a helically coiled resistance wire as heating element in a configuration outlining a flat star pattern; placing the star in-between the said surface portions of the parts to be welded, while adapting its configuration to the contour of the surface portions, which cover the star completely on both sides and are being placed in juxtaposition, separated by the heating element, applying electric current to the resistance wire, so that relatively large annular areas of the surface portions as juxtaposed fuse upon softening of the thermoplastic adjacent the star-shaped resistance wire; and forcing said parts against each other, thereby embedding permanently the coiled heating element in between and providing sealed connection as between said parts with anchoring occurring through bonding of thermoplastic material in the interior of the coiled resistance element and around it with the parts proper as forced against each other.
Claim 2
Independent Claim
164 words
The method of welding thermoplastic parts whereby an areal bond is to be made between surface portions of the parts comprising: providing a helically coiled resistance wire as heating element in a configuration outlining a flat star pattern; placing the star in-between the said surface portions of the parts to be welded, while adapting its configuration to the contour of the surface portions, which cover the star completely on both sides and are being placed in juxtaposition, separated by the heating element, applying electric current to the resistance wire, so that relatively large annular areas of the surface portions as juxtaposed fuse upon softening of the thermoplastic adjacent the star-shaped resistance wire; and forcing said parts against each other, thereby embedding permanently the coiled heating element in between and providing sealed connection as between said parts with anchoring occurring through bonding of thermoplastic material in the interior of the coiled resistance element and around it with the parts proper as forced against each other.
Claim 3
Dependent Claim
24 words
Method as in claim 1, wherein the wire forms a closed loop and current is applied to oppositely located points of the star configuration.
Claim 4
Dependent Claim
21 words
Method as in claim 1, wherein said wire is first heated and dipped into thermoplastic powder for jacketing the coiled wire.
Claim 5
Dependent Claim
59 words
Method as in Claim 1, wherein a first part to be welded is a tube with a lateral port, and a second part to be welded is a sleeve with a saddle-like concave flange to be placed onto the tube, with alignment of the sleeve and of the port, the star-shaped heating element being placed to surround the port.
Claim 6
Dependent Claim
18 words
Method as in Claim 4, and including the step of clamping the flange to the tube during welding.
Claim 7
Dependent Claim
26 words
Method as in claim 4, including the step of providing the inside of the concavely curved flange with an annular groove looping around the sleeve's axis.
Claim 8
Dependent Claim
20 words
Method as in claim 1, including the step of welding the star-shaped heating element first to one of the objects.
Claim 9
Dependent Claim
67 words
Method as in claim 1, wherein one of the surface portions is concavely shaped; the other one of the surface portions is convexly shaped, the star element being welded first to one of the surface portions through application of heating current to the element, followed by superimposing the part with the respective other surface and welding the star element thereto, thereby fusing and bonding the parts together.
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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) | 1979-05-04 | 1979-11-03 | 1980-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-04 | 1983-11-03 | 1984-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-04 | 1987-11-03 | 1988-05-04 | $7700.00 | Window Closed / Lapsed |