US4361336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Epoxy-concrete coated pipe
Assignee: Buderus AG
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Filing: 1980-10-03
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Granted: 1982-11-30
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Expires: 2000-10-03
Abstract
Abstract A cast-iron or steel pipe is coated with a two-component epoxy resin and then, prior to curing of the resin, is coated with a relatively thick layer of hydraulic concrete. A layer of a water-impervious bitumen is then applied over the concrete. The concrete layer does not extend over the spigot in a bell-and-spigot pipe, and a special fitting is provided for such a piece of pipe when the spigot end must be cut off.
Inventors
- 👤 Kurt Reeh
- 👤 Hans-Christoph Jerofke
- 👤 Friedrich Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:36
CPC Classifications
F; F16; F16L; F16L58/00; F16L58/02; F16L58/04; F16L58/06; B; B28; B28B; B28B19/00; B28B19/0038; Y; Y10; Y10S; Y10S138/00; Y10S138/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
90 words
A pipe comprising: a tubular metal pipe core having a central portion, one end formed with a spigot and of smaller outside diameter than said central portion, and another end having a bell; a layer of a two-component epoxy resin directly overlying said core at said central portion, said one end, and said other end, said layer being of greater thickness at said spigot than at said central portion; and a layer of hydraulic concrete directly overlying said layer of resin at said central portion and said other end only.
Claim 2
Dependent Claim
90 words
A pipe comprising: a tubular metal pipe core having a central portion, one end formed with a spigot and of smaller outside diameter than said central portion, and another end having a bell; a layer of a two-component epoxy resin directly overlying said core at said central portion, said one end, and said other end, said layer being of greater thickness at said spigot than at said central portion; and a layer of hydraulic concrete directly overlying said layer of resin at said central portion and said other end only.
Claim 3
Dependent Claim
19 words
The pipe defined in claim 1, further comprising a thin coating of a bitumen overlying said layer of concrete.
Claim 4
Dependent Claim
11 words
The pipe defined in claim 1 wherein said concrete includes fibers.
Claim 5
Dependent Claim
179 words
A pipe assembly comprising: a tubular metal pipe core having a central portion, one end formed with a spigot and of smaller outside diameter than said central portion, and another end having a bell; a layer of a two-component epoxy resin directly overlying said core at said central portion, said one end, and said other end, said layer being of greater thickness at said spigot than at said central portion; a layer of hydraulic concrete directly overlying said layer of resin at said central portion and said other end only and; a fitting having a spigot substantially identical to said spigot of said pipe and fitted in said bell, and at the opposite end a bell similar to said bell of said pipe but having an inside diameter substantially greater than the inside diameter of said pipe and than the outside diameter of the outer surface of said layer of concrete of said central portion of said pipe, whereby if said pipe is cut at its said central portion it can be fitted into the ball of said fitting.
Claim 6
Dependent Claim
179 words
A pipe assembly comprising: a tubular metal pipe core having a central portion, one end formed with a spigot and of smaller outside diameter than said central portion, and another end having a bell; a layer of a two-component epoxy resin directly overlying said core at said central portion, said one end, and said other end, said layer being of greater thickness at said spigot than at said central portion; a layer of hydraulic concrete directly overlying said layer of resin at said central portion and said other end only and; a fitting having a spigot substantially identical to said spigot of said pipe and fitted in said bell, and at the opposite end a bell similar to said bell of said pipe but having an inside diameter substantially greater than the inside diameter of said pipe and than the outside diameter of the outer surface of said layer of concrete of said central portion of said pipe, whereby if said pipe is cut at its said central portion it can be fitted into the ball of said fitting.
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) | 1985-11-29 | 1986-05-31 | 1986-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-29 | 1990-05-31 | 1990-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-29 | 1994-05-31 | 1994-11-30 | $7700.00 | Window Closed / Lapsed |