METHOD AND APPARATUS FOR INSTALLING FLEXIBLE LININGS IN UNDERGROUND PIPES
A method and apparatus for installing a flexible lining tube in an underground pipe by eversion. A pressure vessel is equipped with a gasket that has an arcuate slot for receiving the lining tube in a manner that provides an effective seal without creating undue friction. A guide has a cylindrical wall curved in conformity with the slot and a conical surface leading to the cylindrical wall.
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FIELD OF THE INVENTIONThis invention relates in general to the rehabilitation of underground pipes and deals more particularly with the installation of a flexible lining tube into an underground pipe by everting the lining tube using fluid pressure.
BACKGROUND OF THE INVENTIONSubterranean pipes and conduits such as sewers have been repaired and/or rehabilitated using a number of techniques. One approach that avoids the need for excavation is a process that involves everting a resin impregnated lining tube into the underground pipe using fluid pressure, expanding the tube with fluid pressure, and then curing the tube in place against the interior surface of the sewer pipe. Although this technique has been used for a number of years and has worked well for the most part, it has not been wholly free of problems.
For example, when everting the lining tube into the sewer pipe, significant friction forces must be overcome. As exemplified by U.S. Pat. No. 6,390,795 to Waring et al., the lining tube is typically flattened and extended through a linear slot. The slot must provide a seal that is tight enough to maintain adequate pressure for everting the tube, while the seal must not be so tight that the frictional forces are unduly high. Using a linear slot such as in the Waring patent has proven to be problematic because the seal applies so much friction that there is an excessive restraint on pulling of the liner into the sewer pipe.
SUMMARY OF THE INVENTIONIn accordance with the present invention, an improved method and apparatus is provided for installing flexible lining tubes into underground pipes such as sewers. A pressure vessel is equipped with a gasket in which an arcuate slot is formed. The lining tube is collapsed with its walls overlaid in a double-ply configuration and arranged in a curve to conform with the shape of the arcuate slot. This allows the lining tube to be extended through the slot, preferably with guidance from a forming member having a wall that is curved generally in conformity with the curvature of the arcuate slot. The leading end of the lining tube is coupled with the downstream end of the pressure vessel in a substantially fluid tight manner. Fluid pressure applied to the pressure vessel propels the lining tube out of the vessel and into the pipe as the tube is everted and continuously pulled through the slot until the entirety of the tube has been installed in the underground pipe.
The curved configuration of the slot is a significant feature of the invention. The smooth curvature results in reduced friction to facilitate passage of the lining tube through the slot while reducing the power that is needed for eversion. At the same time, the slot can be custom cut to a size that effects a sufficient seal with the lining tube allowing eversion to proceed without large losses of pressure containment. The construction of the equipment preferably allows different gaskets to be interchanged so that different sizes of lining tubes can be accommodated without the need for wholly different equipment for each size.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.
In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like or similar parts in the various views:
Referring now to the drawings in more detail and initially to
In use of the equipment, the stand 10 is erected on a horizontal support surface that overlies a manhole or other access to the underground pipe which is to be rehabilitated in accordance with the invention. The stand 10 may provide support for an eversion device which is generally identified by numeral 16. As shown additionally in
With reference to
With continued reference to
Optional shims 42 and 44 (
A face plate 48 overlies gasket 40 (and shims 42 and 44 when they are used) and may have the same construction as plate 28, including an arcuate slot 50 which is identical in size and shape to slot 30. When the equipment is assembled, the gasket 40 is sandwiched between plates 28 and 48, with the shims 42 and 44 optionally being sandwiched between the gasket 40 and face plate 48.
A guide 52 is mounted on top of the face plate 48 and acts to provide assistance in guiding of the flexible lining tube in a manner to be explained in more detail. The guide 52 has on its lower portion a cylindrical wall 54 having a lesser diameter than that of the inside edge of slot 50. The top portion of guide 52 takes the form of a frusto-conical surface 56 which tapers upwardly from the upper edge of the wall 54. The guide 52 may be secured in place by a bolt 58 equipped with a tee handle 60 to facilitate tightening and loosening of the bolt 58.
In setting up device 16 for use, the gasket 40 is provided with the arcuate slot 41 that is cut with a curvature to conform with the curvature of slots 30 and 50 and a width and length to accommodate the flexible lining tube that is to be installed. As shown in
After the arcuate slot 41 has been cut in gasket 40 in the appropriate size and shape for the particular lining tube that is being handled, the gasket 40 is applied to plate 28 with slot 41 aligned with slot 30. The face plate 48 is then applied on top of the gasket 40, optionally with the shims 42 and 44 interposed between the gasket 40 and the face plate 48. The face plate 48 is installed with its slot 50 in alignment with slot 41. The shims 42 and 44 are preferably installed when relatively thin tubes 62 are to be handled by the equipment. Screws 68 (see
The tube 62 is arranged for installation and is impregnated with resin in a manner well known in the industry. Tube 62 is initially arranged in its collapsed condition with its walls 64 and 66 overlaid on one another and the leading end of the tube 62 arranged in a curve conforming with the curvature of slot 41. The leading end of tube 62 is extended through slot 41 and through the eversion device 16. As shown in
Fluid pressure may then be applied to the interior of the eversion device 16 through a hose coupling 78 in order to pressurize the inside of the pressure vessel. The fluid is typically air but may be any suitable fluid. The fluid pressure pushes the tube 62 out through the bottom of the end can 72 while everting the tube 62 and pulling it continually through the slot 41. As the tube 62 is everted and extended out through the bottom of the end can 72, it is extended through a manhole (not shown) into an underground sewer pipe. Once the bottom of the manhole has been reached, the eversion device 16 may be moved downwardly on stand 10 into one of the lower pockets 26 in order to provide slack in tube 62 so that the tube can be turned generally horizontally into the sewer pipe.
The fluid pressure is then applied again to the pressure vessel to complete installation of the tube 62 through the desired length of the sewer pipe. The pressure may then be relieved, and the eversion device 16 may be detached from the end can 72 prior to subsequent addition of heat and pressure to the tube 62 in accordance with conventional practice to expand tube 62 against the interior wall of the sewer pipe and cure it in place.
Due to the curved shape of slot 41, the friction encountered when pulling tube 62 through slot 41 is reduced without significant pressure loss within the pressure vessel. The tube 62 is guided into the slot due to the cylindrical shape of wall 54 and the conical shape of surface 56 as the tube 62 feeds into slot 41.
From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.
Claims
1. Apparatus for installing a flexible lining tube in an underground pipe wherein the lining tube has an initially collapsed condition in which walls of the tube are overlaid in a double ply configuration, said apparatus comprising:
- a pressure vessel having a top portion and a bottom portion arranged to be coupled with the lining tube in a substantially fluid tight manner;
- a gasket on said top portion of the pressure vessel having a curved slot through which the lining tube may extend in a substantially fluid tight fit with the lining tube in said collapsed condition thereof; and
- means for applying fluid pressure to said pressure vessel in a manner to pull the lining tube through said curved slot and move the lining tube out of said pressure vessel into said underground pipe while everting the lining tube.
2. Apparatus as set forth in claim 1, including a guide on said top portion of said pressure vessel above said gasket, said guide having a curved wall to assist passage of the lining tube into and through said curved slot.
3. Apparatus as set forth in claim 2, including a generally conical surface on said guide above said curved wall.
4. Apparatus as set forth in claim 1, including:
- a stand adapted to rest on a support surface above the underground pipe, said stand providing a mount for supporting said pressure vessel for pivotal movement about a substantially horizontal axis; and
- a roller on said stand over which the lining tube may pass as the lining tube is pulled through said curved slot.
5. Apparatus as set forth in claim 1, including a plate on said top portion of said pressure vessel underlying said gasket, said plate having an opening in registration with said curved slot.
6. Apparatus as set forth in claim 1, including a pair of plates on said top portion of said pressure vessel between which said gasket is sandwiched, said plates having openings in registration with said curved slot.
7. Apparatus as set forth in claim 6, including a first shim between said plates on the inside of said curved slot and a second shim between said plates on the outside of said curved slot.
8. A method of installing a flexible lining tube in an underground pipe, comprising:
- inserting the lining tube closely through a curved slot into a pressure vessel with the lining tube in a collapsed condition wherein walls of the tube are overlaid in a double ply configuration;
- coupling a leading end portion of the lining tube with the pressure vessel in a substantially fluid tight manner;
- applying fluid pressure to the pressure vessel to pull the lining tube through said curved slot and impel the lining tube out of the pressure vessel into the underground pipe while everting the lining tube.
9. A method as set forth in claim 8, including the step of guiding the lining tube into the curved slot along a wall curved generally in the same curvature as said arcuate slot.
Type: Application
Filed: Feb 23, 2010
Publication Date: Aug 25, 2011
Inventors: Ralph BONANOTTE (Mokena, IL), Doug Beck (Paoli, IN)
Application Number: 12/710,767
International Classification: B29C 65/56 (20060101);