US4401696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lining of pipelines and passageways
Assignee: Insituform International Inc
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Filing: 1981-09-30
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Granted: 1983-08-30
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Expires: 2001-09-30
Abstract
Abstract A method of lining a passageway, such as an undergound sewer is disclosed. A fluent but thixotropic cementitious composition is sprayed onto the surface of the passageway, to form a lining of predetermined thickness and before the material has had time to flow to change its distribution on the surface, a flexible tube is everted onto the applied material, holding it in position until it is sufficiently cured.
Inventors
- 👤 Eric Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:47
CPC Classifications
F; F16; F16L; F16L55/00; F16L55/16; F16L55/162; F16L55/165; F16L55/1651
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
170 words
A method for lining a pipeline or passageway, such as an underground sewer, which includes the steps of: (a) spraying a hardenable thixotropic cementitious material radially outwardly and progressively along the interior of the pipeline or passageway until a lining of the desired thickness has been built up on the interior surface of the pipeline or passageway; (b) everting a flexible tubular membrane into said pipeline or passageway and progressively along the interior of said pipeline closely behind said newly applied cementitious material before said sprayed cementitious material has had an opportunity to flow into an undesirable pattern on the interior of said pipeline or passageway, (c) exerting a sufficient fluid pressure within the interior of said everted flexible tubular membrane so that said flexible tubular membrane will in turn exert a direct outward pressure against said cementitious lining that has been sprayed onto the interior of said pipeline, and (d) maintaining said fluid pressure and said direct pressure until said sprayed lining no longer has a tendency to flow.
Claim 2
Independent Claim
170 words
A method for lining a pipeline or passageway, such as an underground sewer, which includes the steps of: (a) spraying a hardenable thixotropic cementitious material radially outwardly and progressively along the interior of the pipeline or passageway until a lining of the desired thickness has been built up on the interior surface of the pipeline or passageway; (b) everting a flexible tubular membrane into said pipeline or passageway and progressively along the interior of said pipeline closely behind said newly applied cementitious material before said sprayed cementitious material has had an opportunity to flow into an undesirable pattern on the interior of said pipeline or passageway, (c) exerting a sufficient fluid pressure within the interior of said everted flexible tubular membrane so that said flexible tubular membrane will in turn exert a direct outward pressure against said cementitious lining that has been sprayed onto the interior of said pipeline, and (d) maintaining said fluid pressure and said direct pressure until said sprayed lining no longer has a tendency to flow.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein said material comprises a synthetic resinous material.
Claim 4
Dependent Claim
15 words
A method according to claim 2 wherein said synthetic resinous material is admixed with aggregate.
Claim 5
Dependent Claim
14 words
A method according to claim 1 wherein said material comprises a cement mortar material.
Claim 6
Independent Claim
15 words
A method according to any one of claims 1-4 wherein said material includes reinforcing fibers.
Claim 7
Independent Claim
19 words
A method according to any one of claims 1-4 wherein said flexible tubular membrane is composed of plastics material.
Claim 8
Independent Claim
21 words
A method according to any one of claims 1-4 wherein said material is sprayed by means of a rotating spray head.
References Cited (Backward Citations)
GB1230776A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |