Patent US4377545A successfully refreshed from Google Patents.
US4377545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making corrugated reinforced thermoplastic pipe
Assignee: GE Chemicals Inc
•
Filing: 1981-06-16
•
Granted: 1983-03-22
•
Expires: 2001-06-16
Abstract
Abstract Disclosed is a method of making corrugated reinforced thermoplastic pipe having interior and exterior tubes with corrugations therebetween, comprising extruding through a pipe forming die, the interior and exterior tubes of a pipe at one linear rate while extruding a third skin or ribbon at a faster linear rate whereby the third skin buckles between the interior and exterior tubes to create corrugations in the space between the two tubes.
Inventors
- 👤 Robert L. Hornbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:24
CPC Classifications
F; F16; F16L; F16L9/00; F16L9/12; B; B29; B29C; B29C48/00; B29C48/001; B29C48/0013; B29C48/0015; B29C48/03; B29C48/09; B29C48/16; B29C48/18; B29C48/21
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
145 words
A method of making a rigid, stiff, reinforced thermoplastic pipe made of spaced interior and exterior tubes and having spacing and bracing means therebetween comprising, extruding through multiple and separate die passages of a pipe shaping tool at one die passage at a first speed and a first thermoplastic material forming the interior tube, and at a second die passage a second thermoplastic material forming the exterior tube of said pipe while simultaneously forming a space therebetween, and further extruding through a third die passage a third thermoplastic material in the form of a ribbon into said space at a speed faster than said first speed whereby said ribbon buckles, contacts the inner diameter of the exterior tube and the outer diameter of the interior tube and forms a corrugated-like surface which acts as said spacing and bracing means between said interior and exterior tubes.
Claim 2
Independent Claim
145 words
A method of making a rigid, stiff, reinforced thermoplastic pipe made of spaced interior and exterior tubes and having spacing and bracing means therebetween comprising, extruding through multiple and separate die passages of a pipe shaping tool at one die passage at a first speed and a first thermoplastic material forming the interior tube, and at a second die passage a second thermoplastic material forming the exterior tube of said pipe while simultaneously forming a space therebetween, and further extruding through a third die passage a third thermoplastic material in the form of a ribbon into said space at a speed faster than said first speed whereby said ribbon buckles, contacts the inner diameter of the exterior tube and the outer diameter of the interior tube and forms a corrugated-like surface which acts as said spacing and bracing means between said interior and exterior tubes.
References Cited (Backward Citations)
US3561493A
Cited
US3372920A
Cited
US3379221A
Cited
US3538209A
Cited
US4125585A
Cited
US4196464A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-21 | 1986-09-20 | 1987-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-21 | 1990-09-20 | 1991-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-21 | 1994-09-20 | 1995-03-22 | $7700.00 | Window Closed / Lapsed |