Patent US3689929A successfully refreshed from Google Patents.
Patent US3856905A successfully refreshed from Google Patents.
US3856905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oriented plastic tube
Assignee: Dow Chemical Co
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Filing: 1972-09-22
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Granted: 1974-12-24
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Expires: 1992-09-22
Abstract
Abstract Thermoplastic tubing is prepared having radial orientation by deforming tube radially with little or no axial deformation. Such tubes are particularly useful for lining applications such as pipe.
Inventors
- 👤 D Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:18
CPC Classifications
B; B29; B29D; B29D23/00; B29D23/001; B29C; B29C49/00; B29C49/0015; B29C55/00; B29C55/22; B29C55/24; B29C55/30; B29C61/00; B29C61/06; B29C61/08; B29C63/00; B29C63/38; B29C63/46; B29C67/00; Y; Y10; Y10S; Y10S264/00; Y10S264/50; Y10S264/71
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
A method for the preparation of a conduit, the conduit having a plastic liner tube and an outer housing having a liner receiving cavity, the plastic liner tube being of a synthetic thermoplastic composition, the method comprising plastically deforming the tube at a temperature above its glass temperature and a temperature below its softening point to radially compress the tube to a diameter smaller than its original diameter without increasing the length of the tube, reducing the temperature of the tube below the temperature at which it was deformed, positioning the tube within an outer housing in a tube receiving cavity, and heating the tube to a temperature above the temperature of plastic deformatin and below its softening point to cause radial expansion of the tube within the cavity.
Claim 2
Independent Claim
129 words
A method for the preparation of a conduit, the conduit having a plastic liner tube and an outer housing having a liner receiving cavity, the plastic liner tube being of a synthetic thermoplastic composition, the method comprising plastically deforming the tube at a temperature above its glass temperature and a temperature below its softening point to radially compress the tube to a diameter smaller than its original diameter without increasing the length of the tube, reducing the temperature of the tube below the temperature at which it was deformed, positioning the tube within an outer housing in a tube receiving cavity, and heating the tube to a temperature above the temperature of plastic deformatin and below its softening point to cause radial expansion of the tube within the cavity.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the outer housing is a pipe.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the plastic liner tube is deformed by the application of external fluid pressure.
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein the fluid pressure is provided by a liquid.
Claim 6
Dependent Claim
79 words
The method of claim 3 wherein the liner tube is plastically deformed by disposing the liner tube within a pressure tight container having an elongate cavity therein and a mandrel within the cavity and the liner, the mandrel having a region of greater diameter and a region of lesser diameter, the liner tube being deformed about the mandrel as the portion of greater diameter is withdrawn from the cavity and the portion of lesser diameter moved into the cavity.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein the liner tube is plastically deformed by forcing the liner tube through a tapering die.
Claim 8
Dependent Claim
25 words
The method of claim 6 including the step of providing a tapering mandrel within the die and tube and deforming the tube about the mandrel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |