Abstract:
A method and apparatus for repairing a leak in a curved section of plumbing includes a conduit repair liner that has a central section made of polyethylene terephthalate and optionally reinforced to conform to a section of plumbing that has up to a 90 degree bend. The conduit repair liner has straps with an end of each of the straps at an edge and a distal end of each of straps has a section of hook and loop material. The conduit repair liner is wrapped around an inflatable carrier after saturating with a bonding agent then both are positioned within the curved section of the plumbing and the inflatable carrier is inflated. After the bonding agent cures, the inflatable carrier is deflated and removed, leaving the conduit repair liner evenly adhered to the inside surfaces of the curved section of the plumbing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 14/605,407, filed Jan. 26, 2015, the disclosure of which is hereby incorporated by reference. 
     
    
     FIELD 
       [0002]    The invention relates to an improved system and method for rehabilitation of a portion of a structurally damaged or leaking gravity flow system, service line, joint, etc. 
       BACKGROUND 
       [0003]    Ruptures, cracks, and holes often occur in underground conduits such as sanitary sewer lines, storm sewer pipes, and other gravity flow systems and service lines. Repairing these ruptured conduits, from within, is far less expensive and less dangerous than excavating and replacing the damaged sections. One such repair method is to introduce into the conduit a polyester-fiberglass or other structural composite liner impregnated with a thermosetting resin. The liner is wrapped around and secured to an inflatable bladder which is positioned at the rupture and inflated, forcing the repair liner against the inside wall of the conduit. The impregnated composite liner adheres to the damaged inner surface of the conduit and hardens. After completion of the curing process, the bladder is deflated and removed from the conduit. Known related art include U.S. Pat. Nos. 4,995,761 and 5,049,003 to Barton, U.S. Pat. No. 5,628,345 to Fisco, U.S. Pat. No. 5,322,653 to Muller, U.S. Pat. No. 3,202,562 to Lang, et al., U.S. Pat. No. 3,261,374 to Anderson, et al., U.S. Pat. No. 4,776,370 to Long, U.S. Pat. No. 4,880,035 to Vetter, U.S. Pat. No. 4,950,446 to Kinunnoto, et al., U.S. Pat. Nos. 4,985,196 and 5,091,137 to LeDoux, et al., U.S. Pat. No. 5,199,463 to Lippiatt, U.S. Pat. No. 5,203,377 to Harrington, U.S. Pat. Nos. 5,213,727 and 5,346,658 to Gargiulo, U.S. Pat. No. 5,265,648 to Lyon, U.S. Pat. No. 5,501,248 to Kiest, et al., and U.S. Pat. No. 6,019,136 to Walsh, et al., the contents of U.S. Pat. No. 6,019,136 are incorporated by reference. 
         [0004]    The methods and apparatus, for example, as described in the above cited patents provides for repairs of cracks or leaks in straight sections of pipes, but is less useful for curved sections of pipe, especially curves of 90 degrees or more due to the lack of conformity of the repair liner. Such a repair is often needed in the 90 degree curved section of pipe often found beneath a commode, especially when the commode is situated on a cement slab. Prior repairs often required excavating around the 90 degree section, removal of the damaged 90 degree section, replacement with a new 90 degree section and replacement of the concrete that was removed in the excavation. 
         [0005]    What is needed is a system that will repair cracks or leaks in curved sections of pipes without gaining access to the outside surfaces of the pipes (e.g. excavation). 
       SUMMARY 
       [0006]    In one embodiment, a conduit repair system is disclosed including a bonding agent and a conduit repair liner. The conduit repair liner has a mechanism to removably affix the conduit repair liner to a carrier such as straps or other mechanisms. The conduit repair liner is substantially absorbent and soaked in the bonding agent. At least a central section of the conduit repair liner is made of polyethylene terephthalate material so as to be sufficiently resilient as to conform to a section of curved plumbing without forming waves in a surface of the conduit repair liner after the conduit repair liner is inserted into the curved plumbing and the carrier is inflated. In some embodiments, the central section includes a layer of bias-cut reinforcement material. 
         [0007]    In another embodiment, a method of repairing a crack or leak in a curved section of plumbing is disclosed including impregnating a conduit repair liner in a bonding agent. The conduit repair liner has straps with an end of each of the straps at an edge of the conduit repair liner and a distal end of each of straps has a section of hook and loop material. At least a central section of the conduit repair liner comprises polyethylene terephthalate material so as to be sufficiently resilient as to conform to a section of curved plumbing. After impregnation is complete, the conduit repair liner is wrapped around an inflatable carrier and then both are positioned within the curved section of the plumbing. Now, the inflatable carrier is inflated such that the conduit repair liner adheres evenly to the inside surfaces of the curved section of the plumbing. Next, the inflatable carrier is deflated and removed, leaving the conduit repair liner evenly conformed and adhered to the inside surfaces of the curved section of the plumbing. In some embodiments, the inflatable carrier is coated with a release agent (e.g., petroleum jelly) to reduce adherence to the conduit repair liner. 
         [0008]    In another embodiment, a conduit repair system for repairing a curved section of plumbing is disclosed including a bonding agent and a conduit repair liner. The conduit repair liner has straps for removably affixing the conduit repair liner to a carrier (e.g., an inflatable carrier). The conduit repair liner is absorbent and the central section of the conduit repair liner is made of polyethylene terephthalate material so as to be sufficiently resilient as to conform to a section of plumbing that has a 90 degree bend, thereby conforming to the 90 degree bend of the plumbing without forming waves in a surface. After the conduit repair liner is impregnated with the bonding agent, the conduit repair liner is inserted into the curved section of the plumbing, and the carrier is inflated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0010]      FIG. 1  illustrates a perspective view of a conduit repair system liner. 
           [0011]      FIG. 2  illustrates a cross-sectional view of the conduit repair system liner. 
           [0012]      FIG. 3  illustrates a perspective view of the conduit repair system liner being impregnated in resin then wrapped around a deflated carrier. 
           [0013]      FIG. 4A  illustrates a cross-sectional view of the conduit repair system liner wrapped around a deflated carrier and pulled into place within a 90 degree curve of a conduit. 
           [0014]      FIG. 4B  illustrates a cross-sectional view of the conduit repair system liner wrapped around a now inflated carrier in place within the 90 degree curve of a conduit. 
           [0015]      FIG. 4C  illustrates a cross-sectional view of the conduit repair system liner in place within the 90 degree curve of a conduit, after the carrier has been deflated and removed. 
           [0016]      FIG. 5A  illustrates a cross-sectional view of the conduit repair system liner wrapped around a deflated carrier and pulled into place within a curve of a conduit that bends less than 90 degrees. 
           [0017]      FIG. 5B  illustrates a cross-sectional view of the conduit repair system liner wrapped around a now inflated carrier in place within a curve of a conduit that bends less than 90 degrees. 
           [0018]      FIG. 5C  illustrates a cross-sectional view of the conduit repair system liner in place within a curve of a conduit that bends less than 90 degrees, after the carrier has been deflated and removed. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0020]    In prior repair systems, a felt/fiberglass thread material was saturated in resin (e.g., Epoxy), wrapped around a carrier, then positioned within a straight (e.g., substantially linear) section of plumbing in the area of a leak or crack. Using this material and method did not work for curved sections of plumbing, especially in 90 degree curved sections, as the felt/fiberglass material facing the inside radius of the curved section did not compress significantly, while the felt/fiberglass material facing the outside radius of the curved section did not stretch significantly, resulting in waves/bunching of the felt/fiberglass material facing the inside radius of the curved section and pulling of the felt/fiberglass material facing the outside radius of the curved section. The waves/bunching will lead to a reduced conduit diameter and will lead to potential clogging. The pulling also results in reduced diameter, but additionally, will create air-gaps between the felt/fiberglass material and the curved section of plumbing, resulting in a lack of connection and bonding of the felt/fiberglass material and the curved section with the plumbing. 
         [0021]    Referring to  FIGS. 1 and 2 , views of a conduit repair system is shown. The conduit repair system is used to repair any type of pipe in situ, without requiring excavation around the pipe. Any type of pipe/plumbing is anticipated including PCV pipe, plastic pipe, iron pipe, copper pipe, etc. 
         [0022]    The improved conduit repair system shown in  FIGS. 1 and 2  overcomes such issues by using a material that stretches in the area of the bend. The conduit repair system includes a conduit repair system liner  9  that is substantially planar and is made of materials that will soak up a bonding agent  90  (e.g., Epoxy resin). This exemplary conduit repair system liner  9  has two end sections  16  and a central section  30 . The central section  30  comprises materials that provide for stretching when the central section  30  is positioned in a curved area of plumbing as shown in  FIGS. 4A-5C . Although many materials are possible for the central section  30 , one preferred material is fleece, with or without a fiberglass bi-axle reinforcement material. Another preferred material for the central section  30  is polyethylene terephthalate, also known as polar fleece, again with or without a fiberglass bi-axle reinforcement material. It is preferred that the reinforcement material be woven and bias cut to provide resiliency needed to conform to bends in the pipe  2  (see  FIG. 4A ). Generally, woven material has warp and weft threads (horizontal and vertical). Bias cut means that the woven material is cut at an angle of approximately 45 degrees from the warp and weft threads or cut diagonally across the warp and weft threads. Alternately, a chopped fiberglass mat is anticipated. In  FIG. 2 , an exemplary central section  30  is shown including a layer of a stretchy, absorbent material  32  (e.g., fleece or polar fleece), a reinforcement material  34 , and another layer of a stretchy material  36  (e.g., fleece or polar fleece). The optional reinforcement material  34  (e.g., fiberglass bi-axle reinforcement material that is bias-cut) provides additional structural strength and, by being positioned off-axis with respect to the forces of stretching and bias cut, the reinforcement material  34  will stretch with the layers of stretchy, absorbent material  32 / 36 . In some embodiments, the layers of the central section  30  are stitched together, but with a zigzag stitch to allow for stretching and contraction. 
         [0023]    Since the end sections  16  are not required to bend, it is anticipated that the end sections be fabricated either of the same material as the central section  30  or be fabricated as previously known using a layer of felt  14  and a layer of tightly woven fiberglass material  15  to provide additional structural strength. In a preferred embodiment, the layer of felt  14  is stitched or sewn to the layer of tightly woven fiberglass material  15 , though any attachment mechanism is anticipated including glue and/or adhesives. 
         [0024]    To position the conduit repair system liner  9  around a carrier  80  (see  FIGS. 3, 4A, 4B, 5A, 5B ), one or more retaining straps  20  are provided. As will be shown, after impregnating the conduit repair system liner  9  with a bonding agent  90  (e.g., epoxy resin), the conduit repair system liner  9  is wrapped around a carrier  80  and held to the carrier  80  by attaching the retaining strap(s)  20  to one or more attachment areas  16 / 18 , preferably using hook and loop material or any other temporary attachment mechanism. 
         [0025]    Referring to  FIG. 3  illustrates a perspective view of the conduit repair system liner  9  being soaked in a bonding agent  90  (e.g., epoxy resin) then wrapped around a deflated carrier  80 . Although any bonding agent  90  is anticipated, in a preferred embodiment, the bonding agent  90  is resin and, more particularly, epoxy resin. The bonding agent  90  maintains a mechanically bonded connection between the conduit repair system liner  9  and the plumbing  2 / 4  (see  FIGS. 4A-5C ) and, after curing, provides structural strength to the repaired plumbing  2 / 4 . 
         [0026]    The conduit repair system liner  9  is coated with a bonding agent  90  before installation into a local of failure. In some methods of installation, the bonding agent  90  (e.g., epoxy resin) is poured and spread over the conduit repair system liner  9 , substantially covering the conduit repair system liner  9 , for example, using a spreader (not shown). In some embodiments, the bonding agent  90  is sprayed onto the conduit repair system liner  9 . In  FIG. 3 , the conduit repair system liner  9  is dipped into a vat  92  of the bonding agent  90 , allowing the end sections  16  and the central section  30  to adequately absorb the bonding agent  90 . The conduit repair system liner  9  coated with the bonding agent  90  is then wrapped around a carrier  80  and secured using the one or more retaining straps  20  that are affixed to one or more attachment areas  16 / 18 , thereby temporarily holding the conduit repair system liner  9  to the carrier  80 . By whatever mechanism used, it is preferred that the conduit repair system liner  9  be substantially covered and saturated in bonding agent  90 . 
         [0027]    The carrier  80  preferably includes positioning mechanisms  84  for moving the carrier  80  within the plumbing  2 / 4  and an inflation tube  82 , which will be explained. The positioning mechanisms are any device used to properly position the carrier  80  at the local of failure, including, but not limited to ropes, cables, push rods, etc. The method of installation of the conduit repair system liner  9  using the carrier  80  is described with  FIGS. 4A-5C , though it is fully anticipated that the conduit repair system liner  9  be used with other types of carrier systems and using other methods that may or may not use a carrier  80 . 
         [0028]    Referring to  FIGS. 4A-4C , views of the conduit repair system liner  9  during installation within a 90 degree curve of a conduit  2 . After the conduit repair system liner  9  is wrapped around the carrier  80 , the conduit repair system liner  9  and the carrier  80  are positioned within the plumbing  2  as shown in  FIG. 4A , by, for example, pulling/pushing using the positioning lines  84 . Note, that the method shown of positioning the conduit repair system liner  9  and the carrier  80  are examples as it is anticipated that the conduit repair system liner  9  functions with other methods of positioning, all of which are included here within. Note that there is a crack or leak  3  in the plumbing  2 . 
         [0029]    Once the conduit repair system liner  9  and the carrier  80  are in position, the inflatable carrier  80  is inflated (see  FIG. 4B ) through the inflation tube  82 , expanding the conduit repair system liner  9  and forcing the conduit repair system liner  9  to stretch and contact the inside surface of the plumbing  2 . By making the central section  30  from a stretchable material such as fleece or polar fleece, the conduit repair system liner  9  at the smaller radius area of the plumbing  2  compresses without wrinkling while the conduit repair system liner  9  at the larger radius area of the plumbing  2  stretches without creating a gap between the conduit repair system liner  9  and the inside wall of the plumbing  2  (at the larger radius). Therefore, substantially the entire conduit repair system liner  9  (soaked with the bonding agent  90 ) rests against the inner walls of the plumbing  2  in the area of the crack/leak  3 . Now, the carrier  80  is deflated (or evacuated if necessary) and pulled out of the repair area of the pipe  2 , leaving the conduit repair system liner  9  affixed to the inside walls of the plumbing  2  as shown in  FIG. 4C . Once the bonding agent  90  cures, the plumbing  2  has similar or superior structural support, as required by, for example, plumbing beneath roadways, etc. 
         [0030]    Referring to  FIGS. 5A-5C , view of the conduit repair system liner  9  during installation within a curve of a conduit  4  that bends less than 90 degrees. After the conduit repair system liner  9  is wrapped around the carrier  80 , the conduit repair system liner  9  and the carrier  80  are positioned within the plumbing  4  as shown in  FIG. 5A , by, for example, pulling/pushing using the positioning lines  84 . Note, that the method shown of positioning the conduit repair system liner  9  and the carrier  80  are examples as it is anticipated that the conduit repair system liner  9  functions with other methods of positioning, all of which are included here within. Note that there is a crack or leak  5  in the plumbing  4 . 
         [0031]    Once the conduit repair system liner  9  and the carrier  80  are in position, the carrier  80  is inflated (see  FIG. 5B ) through the inflation tube  82 , expanding the conduit repair system liner  9  and forcing the conduit repair system liner  9  to stretch and contact the inside surface of the plumbing  4 . By making the central section  30  from a stretchable material such as fleece or polar fleece, the conduit repair system liner  9  at the smaller radius area of the plumbing  4  compresses without wrinkling while the conduit repair system liner  9  at the larger radius area of the plumbing  4  stretches without creating a gap between the conduit repair system liner  9  and the inside wall of the plumbing  4  (at the larger radius). Therefore, substantially the entire conduit repair system liner  9  (soaked with the bonding agent  90 ) rests against the inner walls of the plumbing  4  in the area of the crack/leak  5 . Now, the carrier  80  is deflated (or evacuated if necessary) and pulled out of the repair area of the pipe  4 , leaving the conduit repair system liner  9  affixed to the inside walls of the plumbing  4  as shown in  FIG. 5C , where curing bonds the conduit repair system liner  9  affixed to the inside walls of the plumbing  4 . 
         [0032]    Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
         [0033]    It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.