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A flexible inflatable packer for use in installation of a sealant such as grout in joints and defects in a conduit such as a sewer pipe, and a method for sealing defects in a conduit by use of such a packer. The packer can collapse to a slender configuration for movement through a small conduit to a

A flexible inflatable packer for use in installation of a sealant such as grout in joints and defects in a conduit such as a sewer pipe, and a method for sealing defects in a conduit by use of such a packer. The packer can collapse to a slender configuration for movement through a small conduit to a location along the length of the conduit where repair is needed. The packer can be inflated to place a sealing portion adjacent each end of the packer into sealing contact with the interior of the conduit, while a centrally located portion of the packer defines space into which a fluid sealant can be installed to repair cracks or holes in the conduit. The centrally located portion of the packer supports the sealant material during a process of curing.

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1. A packer for use in repair of conduits, comprising: (a) an elongate, collapsible, unitary and elastically inflatable, wholly flexible, hollow body having opposite first and second ends, respective first and second sealing portions adjacent said first and second ends, and a sealant placement porti

1. A packer for use in repair of conduits, comprising: (a) an elongate, collapsible, unitary and elastically inflatable, wholly flexible, hollow body having opposite first and second ends, respective first and second sealing portions adjacent said first and second ends, and a sealant placement portion located between said sealing portions;(b) each of said sealing portions of said body including a flexible fluid-tight wall that is elastically expansible radially in response to increasing internal pressure, to cause said sealing portions to engage an interior surface of a conduit sealingly when said body is inflated;(c) said sealant placement portion of said body being elastically expansible radially at a lesser rate than said sealing portions to approach said interior surface of a conduit in response to increasing internal pressure;(d) a sealant conduit being incorporated in said body proximate said first end thereof, said sealant conduit extending longitudinally along an outer side of said flexible fluid-tight wall of said first sealing portion; and(e) a sealant discharge port communicating with said sealant conduit and located adjacent said sealant placement portion of said body. 2. The packer of claim 1 wherein said sealant conduit extends longitudinally along a part of a length of said sealant placement portion and said sealant discharge port is located between said first and second sealing portions of said body. 3. The packer of claim 1 including a plurality of sealant conduits. 4. A packer for use in repair of conduits, comprising: a an elongate, elastically hollow body having opposite first and second ends, respective first and second sealing portions adjacent said first and second ends, and a sealant placement portion located between said sealing portions;(b) each of said sealing portions of said body including a flexible fluid-tight wall that is elastically expansible radially in response to increasing internal pressure, to cause said sealing portions to engage an interior surface of a conduit sealingly when said body is inflated;(c) said sealant placement portion of said body being elastically expansible radially at a lesser rate than said sealing portions to approach said interior surface of a conduit in response to increasing internal pressure;(d) a plurality of sealant conduits joined to said body roximate said first end thereof, said sealant conduits extending longitudinally along an outer side of said flexible fluid-tight wall of said first sealing portion and defining respective associated sealant discharge ports located closely adjacent each other; and(e) a respective sealant discharge port communicating with each of said sealant conduits and located adjacent said sealant placement portion of said body. 5. The packer of claim 4 wherein said sealant discharge ports overlap one another. 6. The packer of claim 1 wherein said sealant conduit is of elastomeric material and is collapsible to a configuration conforming to an exterior shape of said first sealing portion of said body. 7. A packer for use in repair of conduits, comprising: (a) an elongate, elastically inflatable, flexible, hollow body having opposite first and second ends, respective first and second sealing portions adjacent said first and second ends, and a sealant placement portion located between said sealing portions;(b) each of said sealing portions of said body including a flexible fluid-tight wall that is elastically expansible radially in response to increasing internal pressure, to cause said sealing portions to engage an interior surface of a conduit sealingly when said body is inflated;(c) said sealant placement portion of said body being elastically expansible radially at a lesser rate than said sealing portions to approach said interior surface of a conduit in response to increasing internal pressure;(d) a sealant conduit being joined to said body proximate said first end thereof, said sealant conduit extending longitudinally along an outer side of said flexible fluid-tight wall of said first sealing portion, and a portion of said sealant conduit being protected by an exterior cover of elastomeric material adhered to an exterior surface of said fluid-tight wall of said sealing portion of said body and a cushioning body being located adjacent said sealant conduit between said exterior cover and said exterior surface of said fluid-tight wall of said sealing portion; and(e) a sealant discharge port communicating with said sealant conduit and located adjacent said sealant placement portion of said body. 8. The packer of claim 1 wherein each of said sealing portions and said sealant placement portion has a respective diameter and wherein said diameter of said sealant placement portion is less than said diameter of either of said sealing portions when said packer is free from restriction by a surrounding structure and is inflated to an internal pressure great enough to cause said body to expand elastically. 9. A packer for use in repair of conduits, comprising: (a) an elongate, elastically inflatable, flexible, hollow body having opposite first and second ends, respective first and second sealing portions adjacent said first and second ends, and a sealant placement portion located between said sealing portions;(b) each of said sealing portions of said body including a flexible fluid-tight wall that is elastically expansible radially in response to increasing internal pressure, to cause said sealing portions to engage an interior surface of a conduit sealingly when said body is inflated;(c) said sealant placement portion of said body being elastically expansible radially at a lesser rate than said sealing portions to approach said interior surface of a conduit in response to increasing internal pressure;(d) a sealant conduit being joined to said body proximate said first end thereof, said sealant conduit extending longitudinally along an outer side of said flexible fluid-tight wall of said first sealing portion; and(e) a sealant discharge port communicating with said sealant conduit and located adjacent said sealant placement portion of said body, and wherein said body, in a compact, slender configuration, defines a plurality of longitudinally extending folds and has a width that is less than about ⅔ of a diameter of one of said sealing sections when said body is inflated. 10. The packer of claim 9 wherein said body includes at least a pair of opposite inwardly directed folds and at least two pairs of laterally outwardly projecting folds. 11. The packer of claim 9 wherein said body has at least four inwardly directed folds. 12. The packer of claim 9 wherein said packer in said compact, slender configuration is slender enough to fit through a conduit having a diameter no greater than ½ of a diameter of a conduit in which said packer is intended to be used. 13. A packer for use in repair of conduits, comprising: (a) an elongate, elastically inflatable, flexible, hollow body having opposite first and second ends, respective first and second sealing portions adjacent said first and second ends, and a sealant placement portion located between said sealing portions;(b) each of said sealing portions of said body including a flexible fluid-tight wall that is elastically expansible radially in response to increasing internal pressure, to cause said sealing portions to engage an interior surface of a conduit sealingly when said body is inflated;(c) said sealant placement portion of said body being elastically expansible radially at a lesser rate than said sealing portions to approach said interior surface of a conduit in response to increasing internal pressure;(d) a sealant conduit being joined to said body proximate said first end thereof, said sealant conduit extending longitudinally along an outer side of said flexible fluid-tight wall of said first sealing portion; and(e) a sealant discharge port communicating with said sealant conduit and located adjacent said sealant placement portion of said body; and(f) a stiff but resiliently flexible pushrod extending longitudinally within said body from said first end to said second end. 14. The packer of claim 13, wherein said pushrod has a leading end extending outward longitudinally from said second end of said body, and wherein said pushrod has a guide-ball carried on said leading end thereof. 15. The packer of claim 1 wherein said flexible fluid-tight wall of each of said sealing portions has a respective wall thickness and wherein said sealant placement portion includes a flexible fluid-tight wall and has a wall thickness that is greater than said respective wall thicknesses of said sealing portions, whereby said sealing portions are able to expand at a greater rate than said sealant placement portion in response to increasing fluid pressure within said body. 16. The packer of claim 15 wherein said flexible fluid-tight wall of said sealant placement portion includes a plurality of plies of supporting fabric. 17. The packer of claim 15 wherein said flexible fluid-tight wall of said sealant placement portion comprises a significant amount of an elastomeric material which has a higher modulus of elasticity than an elastomeric material that is a primary material of said sealing portions. 18. A packer for use in repair of conduits, comprising: (a) an elongate, elastically inflatable, flexible, hollow body having opposite first and second ends, respective first and second sealing portions adjacent said first and second ends, and a sealant placement portion located between said sealing portions;(b) each of said sealing portions of said body including a flexible fluid-tight wall that is elastically expansible radially in response to increasing internal pressure, to engage an interior surface of a conduit sealingly when said body is inflated;(c) said sealant placement portion of said body being elastically expansible radially at a lesser rate than said sealing portions to approach said interior surface of a conduit in response to increasing internal pressure;(d) a sealant conduit being joined to said body proximate said first end thereof, said sealant conduit being located entirely externally of an inflatable space within said elastically inflatable hollow body and being covered by a cover layer of elastic material attached to an exterior surface of said flexible wall of said first sealing portion of said body and extending longitudinally along an outer side of said flexible fluid-tight wall of said first sealing portion; and(e) a sealant discharge port communicating with said sealant conduit and located adjacent said sealant placement portion of said body. 19. The packer of claim 1 wherein said second sealing portion has a length that is greater than a length of said first sealing portion. 20. The packer of claim 19 wherein said length of said second sealing portion is at least 150 percent of said length of a said first sealing portion. 21. A method for repairing a conduit, comprising: (a) inserting an elongate elastically inflatable packer in a slender configuration into a conduit that is to be repaired;(b) utilizing a leading end portion of a flexible rod extending longitudinally through and beyond a leading end of the packer to guide the packer through the conduit;(c) inflating a pair of sealing portions of the packer to close the conduit sealingly in locations spaced apart longitudinally along the conduit and spanning a defective section to be repaired;(d) thereafter, conducting a quantity of a sealant material in fluid form into a space surrounding a sealant placement portion of the packer located between the ones of said pair of sealing portions, while maintaining closure of the conduit in the spaced apart locations spanning the defective section; and(e) urging a part of said quantity of said sealant material into a defect in said defective section. 22. The method of claim 21 including the step of restricting radial expansion of the sealant placement portion of the packer while inflating said sealing portions, thereby providing said space surrounding said sealant placement portion. 23. The method of claim 21 including the step of defining an annular space surrounding said sealant placement portion within a conduit being repaired and between said sealing portions of said body, when said body is inflated with said sealing portions in effective sealing contact against an interior surface of said conduit. 24. The method of claim 21 including delivering said quantity of said sealant material to said space surrounding said sealant placement portion of said packer in separately measured quantities of at least two components thereof. 25. The method of claim 24 wherein delivering said quantity of sealant material includes keeping said at least two components separate from each other until arrival in a location adjacent the sealant placement portion of said packer, and including the further step of mixing said at least two components with one another in said space surrounding said sealant placement portion. 26. The method of claim 25 including delivering said components of said sealant material by repeatedly delivering a respective small quantity of each of said components in a predetermined order to said location adjacent said sealant placement portion of said packer and within said conduit until a desired amount of sealant material has been delivered to the defective section of said conduit. 27. The method of claim 24 including the further step of delivering said components of said sealant material through respective separate flexible tubes, each of said flexible tubes extending longitudinally along a first one of said sealing portions of said packer to said sealant placement portion thereof. 28. The method of claim 24 wherein said sealant material comprises a first component consisting essentially of a cement slurry and a second component consisting essentially of sodium silicate solution. 29. The method of claim 21 including the further step of thereafter holding the sealant material in place long enough for the sealant material to cure into a form effective to repair the defect. 30. The method of claim 21 including the step of collapsing said packer into said slender configuration by deflating an inflatable body of said packer and folding said body along longitudinally extending folds incorporated in said body to give said body a reduced width. 31. The method of claim 30 wherein said step of collapsing said packer includes reducing fluid pressure within said inflatable body below ambient atmospheric pressure. 32. The method of claim 30 including the step of placing said packer in said location along said conduit by pushing said packer in said slender configuration into said conduit through an accessible conduit smaller than the conduit to be repaired and thence pushing said packer along said conduit that is to be repaired. 33. The method of claim 30 including the step of pushing said packer longitudinally through said conduit to said defective section thereof. 34. The method of claim 22 including the further steps of thereafter deflating the packer and withdrawing it from said defective section of said conduit, and subsequently cutting away a quantity of excessive sealing material from an interior of said defective section of said conduit. 35. The method of claim 22 including the step of using a television camera inside said conduit being repaired to observe said packer during installation of said sealant material and to detect leakage of said sealant material around said first sealing portion. 36. The method of claim 21 wherein said step of inserting an elongate elastically inflatable packer in a slender configuration into a conduit that is to be repaired includes utilizing a portion of said flexible rod to push said packer longitudinally into said conduit that is to be repaired.