US4758302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heating apparatus for thermoplastic pipe
Assignee: Du Pont UK Ltd
•
Filing: 1987-04-09
•
Granted: 1988-07-19
•
Expires: 2007-04-09
Abstract
Abstract Heating apparatus particularly useful for installing heat expandable plastic pipe liner comprising a radiant heater and air circulation means for the uniform distribution of heat about the circumference of the plastic pipe.
Inventors
- 👤 Finn Hannover
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:58
CPC Classifications
B; B29; B29C; B29C63/00; B29C63/0065; B29C63/0069; B29C63/38; B29C63/46; H; H05; H05B; H05B3/00; H05B3/10; H05B3/16; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0822; Y; Y10; Y10T; Y10T156/00; Y10T156/17; Y10T156/1788
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
128 words
An apparatus for internally heating a substantially cylindrical pipe, the apparatus having anterior and posterior ends and comprising: (a) a platform; (b) at least one radiant heating element mounted on the platform; (c) a spiral air tube mounted on the platform to encircle the heating element at least once in a direction axial to the liner, the air tube having a plurality of apertures formed therein positioned to create a circumferential air flow within the pipe; (d) electrical and pressurized air sources functionally connected to the radiant heating element and air tube, respectively; (e) means for moving the platform through the pipe; and (f) a diametric gasket positioned anterior to the heating element to separate the apparatus from the portion of the pipe anterior to the heating element;
Claim 2
Independent Claim
128 words
An apparatus for internally heating a substantially cylindrical pipe, the apparatus having anterior and posterior ends and comprising: (a) a platform; (b) at least one radiant heating element mounted on the platform; (c) a spiral air tube mounted on the platform to encircle the heating element at least once in a direction axial to the liner, the air tube having a plurality of apertures formed therein positioned to create a circumferential air flow within the pipe; (d) electrical and pressurized air sources functionally connected to the radiant heating element and air tube, respectively; (e) means for moving the platform through the pipe; and (f) a diametric gasket positioned anterior to the heating element to separate the apparatus from the portion of the pipe anterior to the heating element;
Claim 3
Dependent Claim
21 words
An apparatus of claim 1 comprising at least two radiant heating elements, positioned equidistant from the center of the support rod.
Claim 4
Dependent Claim
30 words
An apparatus of claim 1 further comprising a diametric gasket positioned posterior to the heating element, to seal the apparatus from the portion of the pipe behind the heating element.
Claim 5
Dependent Claim
19 words
An apparatus of claim 1 wherein the air tube and the heating element are mounted on a common suspension.
References Cited (Backward Citations)
US2516242A
Cited
US3043017A
Cited
US3429954A
Cited
US3706824A
Cited
US4415584A
Cited
US4338153A
Cited
GB2084686A
Cited
US4494584A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |