US4956041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of lining branch pipe portion of underground main pipe with rigid plastics tube
Assignee: Osaka Bousui Construction Co Ltd
•
Filing: 1988-12-23
•
Granted: 1990-09-11
•
Expires: 2008-12-23
Abstract
Abstract A method of forming a rigid or semirigid plastics tube lining over the inner surface of a branch pipe portion as joined at its one end to an underground main pipe through the other end thereof substantially open to the surface of the ground as a work opening, the method being characterized by inserting a rigid or semirigid plastics tube into the branch pipe portion from the work opening with the forward end of the tube substantially closed, and subsequently supplying a fluid into the tube to inflate the tube radially of the branch pipe by applying heat and pressure to the tube with the fluid from inside directly or indirectly and thereby line the branch pipe portion with the rigid plastics tube. The pipe portion can be lined from the ground surface efficiently without necessitating labor for excavation of the ground, cutting off the branch pipe portion and restoring the piping to the original state.
Inventors
- 👤 Yasuo Miyazaki
- 👤 Akira Kamide
- 👤 Shigeki Watari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:25
CPC Classifications
B; B29; B29C; B29C63/00; B29C63/26; F; F16; F16L; F16L55/00; F16L55/16; F16L55/162; F16L55/165; B29C63/28; F16L55/179; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052; Y10T156/108
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
203 words
A method of forming a plastic tube lining over an inner surface of a branch pipe connected to an underground main pipe at one end thereof with the other end open to the surface of the ground, the method comprising the steps of: preparing a rigid plastic tube to be used as a liner, the rigid plastic tube having a discharge means comprising a front plug at a distal end thereof for discharging a fluid therethrough; inserting the rigid plastic tube equipped with the discharge means through said other end until at least the discharge means extends into the underground main pipe; feeding a heated and pressurized fluid continuously into the rigid plastic tube in order to radially expand the rigid plastic tube until the rigid plastic tube contacts the inside of the branch pipe while discharging the used fluid out of the rigid plastic tube through the discharge means; and cutting off a part of the rigid plastic tube within the underground main pipe; wherein the front plug at said distal end of said rigid plastic tube has an elongated discharge pipe connected thereto and extending along the branch pipe from said front plug to said other end of said branch pipe.
Claim 2
Independent Claim
203 words
A method of forming a plastic tube lining over an inner surface of a branch pipe connected to an underground main pipe at one end thereof with the other end open to the surface of the ground, the method comprising the steps of: preparing a rigid plastic tube to be used as a liner, the rigid plastic tube having a discharge means comprising a front plug at a distal end thereof for discharging a fluid therethrough; inserting the rigid plastic tube equipped with the discharge means through said other end until at least the discharge means extends into the underground main pipe; feeding a heated and pressurized fluid continuously into the rigid plastic tube in order to radially expand the rigid plastic tube until the rigid plastic tube contacts the inside of the branch pipe while discharging the used fluid out of the rigid plastic tube through the discharge means; and cutting off a part of the rigid plastic tube within the underground main pipe; wherein the front plug at said distal end of said rigid plastic tube has an elongated discharge pipe connected thereto and extending along the branch pipe from said front plug to said other end of said branch pipe.
Claim 3
Dependent Claim
14 words
The method of claim 1, wherein the rigid plastic tube is previously radially collapsed.
Claim 4
Dependent Claim
38 words
The method of claim 1, wherein the rigid plastic tube is provided with a seal member at a distal end thereof in order to provide a seal at a junction between the branch pipe and the underground pipe.
Claim 5
Dependent Claim
10 words
The method of claim 1, wherein the fluid is steam.
References Cited (Backward Citations)
US281529A
Cited
US3050786A
Cited
GB932910A
Cited
US3230129A
Cited
US3211574A
Cited
JPS5375281A
Cited
DE2719320B1
Cited
DE2728056A1
Cited
JPS5447768A
Cited
JPS5511839A
Cited
GB2041147A
Cited
US4434115A
Cited
JPS57154581A
Cited
JPS5824679A
Cited
JPS5888281A
Cited
US4773450A
Cited
JPS62179921A
Cited
JPS62284727A
Cited
US4752511A
Cited
FR2607742A1
Cited
JPH01274026A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |