US4240850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Making thermally-insulated tubing
Assignee: KM Kabelmetal AG
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Filing: 1979-04-30
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Granted: 1980-12-23
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Expires: 1999-04-30
Abstract
Abstract A strip is folded longitudinally around a tube to, thereby, establish an assembly of an inner and a concentric outer tube; individual slotted foam strips are placed in transverse orientation onto the strip just prior to folding; they will become spacers with V-shaped notches. Just prior to closing the outer split tube, foam is introduced into the ring space between the tubes which will spread freely through the notches.
Inventors
- 👤 Hans-Joachim Arntz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:17
CPC Classifications
F; F16; F16L; F16L59/00; F16L59/12; B; B29; B29C; B29C44/00; B29C44/20; B29C44/32; B29C44/322; B29C44/324; F16L59/02; F16L59/021; Y; Y10; Y10S; Y10S138/00; Y10S138/09; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1036; Y10T156/1038; Y10T156/1051
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
129 words
A method of making a thermally insulated, concentric tube system on a continuous basis which includes the steps of providing a first tube, forming a strip longitudinally into a split tube around the first tube, and closing the first tube, the improvement comprising: placing individual strip pieces of thermally insulating material on the strip, the strip pieces extending transversely to the longitudinal direction of the tubes, the pieces being sequentially folded around the first tube to become spacers as the strip is progressively folded into the split tube, at least one axial gap remaining in each resulting spacer; and filling space between the split tube and the first tube with foam prior to closing the split tube on account of said folding, the foam spreading axially through the gaps.
Claim 2
Independent Claim
129 words
A method of making a thermally insulated, concentric tube system on a continuous basis which includes the steps of providing a first tube, forming a strip longitudinally into a split tube around the first tube, and closing the first tube, the improvement comprising: placing individual strip pieces of thermally insulating material on the strip, the strip pieces extending transversely to the longitudinal direction of the tubes, the pieces being sequentially folded around the first tube to become spacers as the strip is progressively folded into the split tube, at least one axial gap remaining in each resulting spacer; and filling space between the split tube and the first tube with foam prior to closing the split tube on account of said folding, the foam spreading axially through the gaps.
Claim 3
Dependent Claim
41 words
A method as in claim 1, the strip pieces being shorter than the circumference of the first tube, so that the gap results from failure of the ends of the strip pieces to abut upon being folded around the first tube.
Claim 4
Dependent Claim
28 words
A method as in claim 1 or 2, wherein the strip pieces have slits, resulting in V-shaped notches which include, or are in addition to, the said gap.
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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |