Patent Abstract:
A lining apparatus and method is provided that obviates the need for a bladder to press the liner against the host pipe. The lining apparatus may include an extension tube sealed to the liner at one of its ends with an inversion mechanism attached to the other end of the liner for inverting the liner to its desired position within the pipe to be repaired. The lining apparatus can also avoid the use of an extension tube by temporarily closing the liner during the inversion process so that the liner can be inflated when pressurized by a fluid and then sealing an open end of the liner after it has been inverted into the pipe.

Full Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a bladderless pipeliner and method for using same. Prior apparatus and methods for repairing pipelines have included an inversion bladder tube as well as a felt liner tube. The liner tube is positioned inside the bladder tube and the action of the bladder tube during inversion causes the liner and the bladder tube to invert together. Once the inversion is complete the bladder that was originally on the outside of the liner is reversed to be on the inside, and the liner which was originally inside the bladder has been reversed to be outside the bladder. The bladder is then inflated to press the liner against the sewer pipe wall. These two together may be referred to as a liner/bladder assembly. 
     In these prior art liner/bladder assemblies, the bladder is longer than the liner. The end of the bladder includes a wick and a source of vacuum for facilitating the introduction of resin into the bladder tube to cause impregnation of the liner tube. Since the bladder is longer than the liner, the bladder continues to invert a short distance even when the liner is fully inverted. The bladder portion that extends past the end of the liner keeps the end of the liner open so there is no need to cut the end of the liner. 
     The bladder material used in the prior art has sometimes been made of reinforced urethane. Urethane withstands heat generated during curing of the resin. Urethane also has an excellent stretch characteristic and that is important for the bladder to be sized somewhat smaller than the host pipe. The bladder and liner then both stretch under pressure leaving a smooth bore interior of the newly cured-in-place liner. 
     The urethane bladder is very expensive. It represents approximately 60% of the liner/bladder assembly in raw material cost. Bladder material must be slit into the appropriate lay flat size. It is then welded into a tube and air tested for leaks and burst pressure. Then the liner tube is pulled inside of the bladder tube and this can be a difficult task, especially if the lengths are long. The bladder tube must be laid out straight with a rope passing through it so that the liner can be pulled through the bladder. If the liner is 200 feet long the manufacturing facility must have an assembly table that is at least 200 feet long also. 
     Therefore, a primary object of the present invention is the provision of an improved bladderless pipeliner and method for using same. 
     A further object of the present invention is the use of a bladderless pipeliner which does not include an inversion bladder. 
     A further object of the present invention is the provision of an apparatus and method which are economical to use, efficient in operation, and durable after installing. 
     BRIEF SUMMARY OF THE INVENTION 
     The foregoing objects may be achieved by an apparatus for repairing a pipeline comprising an elongated liner tube having a liner tube wall comprised of a resin absorbent material. The liner tube includes at least first and second ends. The liner tube wall includes first and second opposite wall surfaces. An uncured and unhardened resin impregnates the resin absorbent material of the liner tube wall. An extension tube is provided having a tube shaped open end and a close end. A sealing member detachably secures the tube shaped open end of the extension tube to the first end of the liner tube and forms a substantially fluid tight seal therebetween. A flexible pulling line is connected to the closed end of the bladder extension. 
     Inversion means are connected to the second end of the liner tube for inverting the liner tube from an initial position wherein the first wall surface of the liner tube wall is facing in an inward radial direction and the second wall surface of the liner tube is facing in an outward radial direction to an inverted position wherein the first wall surface faces in an outward radial direction and the second wall faces in an inward radial direction. 
     The term “inversion means” as used herein includes various apparatus shown in the prior art for inverting liner tubes into a pipeline. Examples are shown in U.S. Pat. No. 5,816,293, which shows various embodiments of apparatus for inverting the liner tubes. Another reference, U.S. Pat. No. 6,021,815, shows various types of launcher devices which may be used for repairing a main sewer line or a lateral sewer line, and which will accommodate either elongated cylindrical liner tubes or T-shaped liner tubes. U.S. Pat. Nos. 5,950,682 and 6,039,079 show metal launcher devices which may be used as inversion means. The term inversion means also includes the launcher as shown in  FIGS. 1-4  of the present application and the inverter tank shown in  FIGS. 10 and 11 . Other apparatus for inverting the liner tube, either into the main line or into the lateral line are included in the term “inversion means”. 
     According to a further feature of the present invention, a metal launcher is utilized and includes an inflatable cuff between the launcher tube and the main liner member. A second fluid conduit is connected to the inflatable cuff for inflating the cuff and causing the cuff to exert pressure on the main liner member in an outward direction away from the launcher tube. In this configuration a lateral liner tube is connected to the main liner member to create a T-shaped configuration. The lateral liner tube is included inside the launcher tube whereas the main liner member is positioned outside the launcher tube. 
     According to another feature of the invention, the liner tube wall includes a plastic layer covering the outside of the liner tube when the liner tube is in its initial position and the plastic layer is positioned inside the liner tube after the liner tube is inverted to its inverted position. 
     The method of the present invention comprises taking the liner tube, attaching an inversion means to the first end of the liner tube, and attaching a tube-shaped end of an extension tube to a second end of the liner tube. The extension tube includes a closed end opposite from its tube shaped end. Next, a liquid uncured resin is impregnated into the absorbent material of the liner tube wall. An inversion means is then used to invert the liner tube in the pipeline from an initial position wherein the first wall surface of the liner tube faces in an inward radial direction and the second wall surface of the liner tube faces in an outer radial direction to an inverted position wherein the first wall surface of the liner faces in an outward radial direction and the second wall surface faces in an inward radial direction. The resin is then permitted to cure and harden. Finally the extension tube is pulled away from the liner tube to detach the extension tube from the liner tube. 
     According to another feature of the method, the attachment step comprises using a sealing member to attach the liner to the bladder extension. The step of pulling the extension tube away from the liner tube further comprises detaching the sealing member from the liner tube while keeping the sealing member attached to the bladder extension. 
     The present invention can also be practiced without the use of extension tube. Here, the second end of the liner tube is temporarily closed. When the liner tube is inverted, the means used to close the second end of the liner tube is blown off, leaving the liner tube fully inverted and open at its second end. Next, an inflatable plug is inserted into the open second end of the liner tube, and the plug is inflated so as to seal the second end of the liner tube. 
     According to another feature of the invention, the pipeline comprises a main pipeline and a lateral pipeline which form a juncture with the main pipeline. The method further comprises a main liner portion outside the launcher device and a lateral liner portion inside the launcher device before the inversion step. The inflation step further comprises inflating the main liner so as to contact the main pipe. The inversion step further comprises inverting the lateral liner portion out of the launcher device through a launcher device opening in the launcher device into the lateral pipeline. 
     A further feature of the invention includes a tank which is utilized as an inversion means and which contains the liner tube before the inverting step. The tank includes a tank opening and the inverting step comprises inverting the liner tube out of the tank through the tank opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of an embodiment of the present invention. 
         FIG. 1A  is an enlarged sectional view taken along line  1 A- 1 A of  FIG. 1 . 
         FIG. 1B  is a sectional view taken line  1 B- 1 B of  FIG. 1 . 
         FIG. 2  is a sectional view similar to  FIG. 1 , but showing the liner tube in an inverted position. 
         FIG. 3  is a view similar to  FIG. 2 , but showing the initial pulling of the extension tube to remove it from the liner tube. 
         FIG. 4  is a view similar to  FIG. 3  showing the extension tube completely removed from the liner tube. 
         FIG. 5  is a perspective view of a modified form of the invention. 
         FIG. 6  is a sectional view showing the modification of  FIG. 5  in a main pipeline and lateral pipeline junction. 
         FIG. 7  is a view similar to  FIG. 6 , but showing the inflatable cuff in its inflated position. 
         FIG. 8  is a view similar to  FIGS. 6 and 7 , but showing the lateral pipeliner in its inverted condition. 
         FIG. 9  is a view similar to  FIG. 8 , but showing the extension tube fully removed from the lateral pipe liner. 
         FIG. 10  is a sectional view similar to  FIG. 6 , illustrating an embodiment of the present invention without an extension tube. 
         FIG. 11  is a sectional view showing the lateral liner tube completely inverted and sealed with an inflatable plug. 
         FIG. 12  is a sectional view showing a modified form of the inversion means which can be used for the present invention. 
         FIG. 13  is a sectional view of a manhole and pipeline utilizing the inversion means of  FIG. 12  for inverting the pipeliner of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, the numeral  10  generally designates a main pipeline requiring repair. The numeral  12  refers to the apparatus for repairing the main pipeline. Apparatus  12  includes a launcher tube assembly  14  comprising a launcher tube  16  and a launcher end cap  18 . End cap  18  includes a fluid inlet  20  for introducing fluid under pressure and a rope opening  22  for permitting a rope to exit through the launcher end cap. At the forward end of the launcher tube assembly  14  is a launcher collar  24  which is comprised of a rigid material such as metal. The launcher collar  24  defines a launcher tube opening  26 . 
     A liner tube  28  is comprised of a felt material  30  and a plastic layer  32  ( FIG. 1A ). The felt material is adapted to absorb a liquid resin, and the plastic material is adapted to provide an impervious smooth continuous surface. In the position shown in  FIGS. 1 and 1A , the plastic layer  32  is located on the outside of the liner tube  28  and the felt layer  30  is located on the inside. During the inversion process which will be described below, the liner tube is inverted so that the felt layer  30  is on the outside of the liner tube and the smooth plastic layer  32  is on the inside of the liner tube  28 . 
     Liner tube  28  includes a first end  34  which is folded back on the outer surface of the launcher tube  12  in alignment with the rigid collar  24 . A second end  36  is positioned inside the launcher tube  28 . A pair of launcher flaps  38  are positioned outside the first end  34  of liner tube  28 , and extend forwardly to receive a pulling line  40  through grommets  44 . The pulling line  40  includes a releasable knot  42  which permits the pulling line to be removed from the device after the sewer line repair has been complete. 
     A clamp  46  surrounds the first end  34  of liner tube  28 , the end of the launcher tube  16 , and the rigid collar  24  so as to clamp those parts together. 
     Attached to the second end  36  of the liner tube  28  is an extension tube  48 . Extension tube  48 , preferably made from a flexible “lay flat” hose, includes a closed end  50  having a plug  52  therein. A flexible line  54  is attached to the plug  52  and extends through the rope opening  22  in the launcher end cap  18 . The extension tube  48  also includes a tubular open end  56  which surrounds the second end  36  of liner tube  28 . Use of a rigid plug  52  in the end of the extension tube  48  can, in some applications, make it difficult to navigate around bends in the pipeline  10 . An alternative (not shown) is to fanfold the closed end  50  of the extension tube into several layers and put a grommet through the layers with a rope fed through the grommet. 
     An adhesive material  58 , such as a 2-sided tape (preferably carpet tape or pressure sensitive tape) or a liquid adhesive (preferably Tetrahydrofuran (THF)) is used to attach the open end  56  of the extension tube  48  to the liner tube  28 . The adhesive material  58  provides a sealed connection between the liner tube  28  and the extension tube  48 . Extension tube  48  may be further attached to the liner tube by means of connecting tabs  60  which are welded to the extension tube  48 , and which are attached to the felt surface  30  of the liner tube  28  by means of frangible stitches  62 . The term “frangible stitches” refers to stitches which are connected to the liner tube  28 , but which can be torn away by the pulling of rope  54 . This further means of attaching the extension tube  48  to the liner tube  28  by using connecting tabs  60  is an added feature and is not necessary to perform the invention by using an adhesive to attach the extension tube  48  to the liner tube  28 . 
     In operation, the liner tube  28  is impregnated with a liquid uncured resin. Resin impregnates the felt material  30 , and remains in an uncured state. The liner tube  28  is then pulled within the launcher tube  12  and is transported to the location of the pipeline requiring repair.  FIG. 1  illustrates the apparatus  12  located within a main sewer line  10  which requires repair. 
       FIG. 2  illustrates the apparatus in its inverted condition. The axial lengths of liner tube  28  and launcher tube  16  are shown shorter than in  FIG. 1  so as to show the various layers in enlarged scale. To obtain this inversion, fluid under pressure, preferably air, is introduced through fluid inlet  20 . This causes the liner tube  28  to invert outwardly through the collar  24  to the position shown in  FIG. 2 . The extension tube  48  also inverts outwardly, and the line  54  is permitted to extend outwardly with the inversion. In the position shown in  FIG. 2 , the adhesive material  58  has reversed its position, and is located inside the liner tube  28  and the extension tube  18 . In  FIG. 1  the adhesive material is on the outside of the liner tube  28  and the extension tube  48 . 
     Similarly the tabs  60  are inverted from a position outside the liner tube  28  and the extension tube  48  ( FIG. 1B ) to an inverted position wherein one of their ends is positioned inside the liner tube  28  and the other of their ends (with stitches  62  thereon) is positioned between adhesive material  58  and liner tube  28 . 
     After the liner tube  28  has been inverted into the main pipeline, the resin is permitted to cure and harden. The extension tube  48  preferably includes an air exhaust port that for regulating and controlling the pressure and temperature within the line  28  during the curing process. After the resin has cured and hardened, the rope  54  is pulled to cause the extension tube  48  to break away from the liner tube  28 . In this break away action, the tabs  60 , because of their frangible stitching  62 , are easily torn away from the interior of the liner tube  28 . The adhesive material  58  is shown in  FIG. 3  to be folded back upon itself during the pulling action. This permits the adhesive material to peel away from the interior surface of the liner tube  28  while at the same time remaining attached to the extension tube  48 . 
       FIG. 4  illustrates the extension tube, the tabs  60 , and the adhesive material  58  completely removed from the interior of the liner tube  28 . 
       FIGS. 5-9  illustrate the use of the present bladderless liner in a T-shaped configuration for repairing a main pipeline  72  having a lateral pipeline  74  extending there from. The modified assembly is designated generally by the numeral  70 . It is used for repairing a main pipeline  72  having a lateral pipeline  74  extending therefrom. 
     Assembly  70  includes a metal launcher tube  76  having closed opposite ends and a launcher tube opening  78  ( FIG. 6 ) intermediate those opposite ends. At one end of the launcher tube  76  is a fluid inlet  80  having a fluid hose  81  connected thereto. A line opening  82  is adapted to receive a flexible line  104 . At the opposite end of the launcher tube  76  is a grommet  84  having a pull line  86  attached thereto. 
     A T-shaped liner tube  88  includes a main liner member  90  (preferably a flat sheet formed in the shape of a tube) and a lateral liner tube  92  which are joined together forming a liner assembly. The liner assembly is comprised of the resin absorbent material shown in the liner assembly of  FIG. 1 . The main liner member  90  is positioned outside the launcher tube  76  and includes its smooth surface  32  directed inwardly towards the interior of the sewer line  72 . The lateral liner tube  92  is inverted inwardly into the interior of the launcher tube  76 . In this position the lateral liner tube has its smooth surface  32  facing radially outwardly and its felt surface  30  facing radially inwardly. The juncture between the main liner member  90  and the lateral liner tube  92  is provided with a main liner member opening  94 . 
     An extension tube  96  includes a closed end  98  having a plug  100  therein. As described previously, fan folding the closed end  98  of the extension tube  96  and placing a grommet therethrough obviates the need for a plug  100  and in some instances makes it easier to navigate around bends in the pipeline. An open end  102  of the extension tube surrounds the one end of the lateral liner tube  92 . A tape  106  or other adhesive material secures the two together and seals around the periphery of the open end  102 . Tabs  108  are attached to the extension tube  96  and the lateral liner tube  92  in the same manner described for  FIG. 1 . Stitches  110  frangibly attach the tabs  108  to the liner tube  92 . 
     Between the main liner member  90  and the steel launcher tube  76  is an inflatable cuff  112  which includes a first cuff end  114  and a second cuff end  116  which are attached to the outer surface of the metal liner tube  76 . This may be done by vulcanizing, or by adhesive means, or by mechanical means such as clamps or simply friction caused by a tight fit. The cuff  112  has intermediate its opposite ends a cuff opening  118  which is folded over its cuff opening perimeter  120  and which is attached to the launcher tube opening  78  in a manner shown in  FIG. 6 . The cuff  112  includes at one end thereof a fluid inlet  122  to which is attached a fluid hose  124 . 
     In operation the assembly  70  is pulled by means of rope  86  to the appropriate position within the main pipeline  72  so that the launcher tube opening  78  is aligned with the lateral pipeline  74  as shown in  FIG. 6 . During this positioning step the inflatable cuff  112  is deflated so as to permit the assembly to move easily within the main pipeline  72 . 
     Next, the hose  124  is used to introduce fluid such as air into the inflatable cuff  112  so as to cause it to expand radially outwardly and force the main liner member into tight engagement with the interior surface of the main pipeline  72 . This properly positions the main liner member  90 , and it also forms a seal between the main liner member  90  and the main pipeline  72 . 
     Next, air or other fluid is introduced through fluid conduit  81  into the interior of the steel launcher tube  76 . This causes the lateral liner tube  92  to invert upwardly into the lateral pipeline as shown in  FIG. 8 . In this position the main liner member  90  and the lateral liner tube  92  form a T-shaped configuration  88 . 
     The resin is then permitted to cure and harden, and after the curing, the rope  104  is pulled to remove the extension tube  96  from the lateral liner tube  92  in the same manner as described for the embodiment shown in  FIG. 1 .  FIG. 9  shows the extension tube  96  completely removed with the inflatable cuff  112  again deflated. 
     The present invention can also be practiced without an extension bladder. An exemplary embodiment is illustrated in  FIGS. 10 and 11 . Here, the end  93  of the lateral liner tube  92  opposite the main liner member  90  is temporarily closed, preferably by tying a rope  105  around the end  93  of the lateral liner tube  92 . This creates a temporary seal at the end  93  of the lateral liner tube  92  during the inversion process. The rope  105  which is tied to the end  93  of the lateral liner tube  92  is also attached to line  104 . The lateral liner tube  92  is pulled into the launcher tube  76  by pulling on the line  104 . Inverting the lateral liner tube  92  causes the rope  105  that is tied to the end  93  of the lateral liner tube  92  to be pushed off by pressure applied within the lateral liner tube  92 . This leaves the end  93  of the lateral liner tube  92  open with the lateral liner tube  92  in the inverted position. As shown in  FIG. 11 , the end  93  of the lateral liner tube is at a remote portion of the lateral pipe, such that the end  93  cannot be sealed or closed directly by an operator. To overcome this problem, a plug  115  is inserted (typically through a cleanout  117 ) in the end  93  of the lateral liner tube  92  (see  FIG. 11 ). The plug  115  is inflated using a separate air hose  119  to form a seal at the end  93  of the lateral liner tube  92  so as to keep the liner tube  92  under pressure and inflated until the resin has cured. The plug  115  should include an exhaust port (not shown) for regulating the pressure and temperature inside the lateral liner tube  92 . Upon curing of the resin, the plug  115  is deflated and removed. Those skilled in the art having the benefit of this disclosure will appreciate that tape, elastic bands, twine or the like may be substituted for the rope  105  as a means for temporarily closing the end  93  of the lateral liner tube  92 . 
       FIGS. 12 and 13  illustrate a modified form of inversion means which can be used for inverting the liner tube of the present invention. The inversion means comprises a pressure tank  128  having a boss  130  thereon. A tank wall  132  encloses a tank chamber  134 . A fluid inlet boss  136  is also provided and is connected to a fluid conduit  138  which is capable of introducing fluid under pressure into the tank chamber  134 . A valve  148  is capable of opening and closing to permit the introduction or stopping of the fluid under pressure. 
     Within the tank chamber  134  is a liner tube coil  140  formed from a liner tube of the configuration shown in  FIGS. 1-4  or  5 - 9 . A pivot axle  142  is provided at the center. While shown only in a schematic form, the plug  52  and the extension tube  48  are also wound into the coil and are identified by numerals in  FIG. 10 . The flexible line  54  is wound at the center of the coil. 
     The end  34  of the liner tube  28  is folded over on the outside of the boss  130  so that when air is introduced under pressure into the tank chamber  134 , the liner tube  128  inverts out of the boss  130  in the manner shown in  FIG. 11 .  FIG. 11  shows a manhole  144  which is in communication with the main sewer line  150 . The extension tube  48  is attached by means of tape  58  to the liner tube  28 , and the line  54  extends outwardly and upwardly to the top of the manhole  144 . After the inversion is complete, the line  54  is pulled to remove the extension tube from the cured liner tube. 
     In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.

Technology Classification (CPC): 5