Method for water leakage prevention in pipeline

Abstract: A method for water leakage prevention in a portion (10) connecting a first pipeline (12) to a second pipeline (14) having one end communicated with a portion of the first pipeline, comprises the steps of passing elastically deformable drawing means (46,48) from the side of the other end of the second pipeline to the side of one end of the first pipeline, engaging an impermeable cut-off member having an expandable hose portion (22) and a flange portion (24) provided integrally with one end of the hose portion with the drawing means at the side of one end of the first pipeline at the hose portion, drawing the cut-off member from the side of the hose portion into the first and second pipelines by drawing back the drawing means toward the other end of the second pipeline under the engaged condition, and disposing the cut-off member in the first and second pipelines so that the flange portion is positioned within the first pipeline and that the hose portion extends within the second pipeline.

Description: BACKGROUND OF THE INVENTION Field of the Invention: This invention relates to a method for water leakage prevention in a portion connecting a first pipeline to a second pipeline branched off from the first pipeline. Description of the Prior Art: A portion connecting a first pipeline such as a main pipe of sewerage to a second pipeline such as a branch pipe is generally bonded to each other by means of a bonding agent such as mortar in liquid tightness. In general, the bonding agent is peeled off from the first pipeline or the second pipeline only by slightly displacing the first pipeline and the second pipeline relatively to each other. As a result, a space is formed in the connection portion, and the liquid tightness of the connection portion is lowered. When the liquid tightness of the connection portion is lowered, a cut-off treatment of water for preventing water leakage from the space formed in the connection portion is performed. This kind of cut-off treatment of water is generally performed by a so-called chemicals feeding method of injecting a cut-off agent of cement type or liquid type into the space and around the connection portion and then coagulating the cut-off agent. However, the chemicals feeding method has problems as follows: Namely, when the water leakage practically happens, the cut-off agent is diluted with water, flown away, and frequently not hardened. The subsequent treatment for removing the cut-off agent flown away into the pipeline should also be done. In the chemicals feeding method using a cement-type cut-off agent, the cut-off agent after being hardened does not have any elasticity, and therefore, when the pipes are displaced due to vibration, land subsidence or the like, the hardened cut-off agent is peeled off from the pipeline and the resulting cracks are formed in the hardened cut-off agent. As a result, any long-term stable cut-off effect of water is not expected. In the chemicals feeding method using a liquid-type cut-off agent, the mechanical strength of the cut-off agent is weak, and the cut-off effect of water is not maintained stable for a long period of time. GB 2041147 describes a method of renovating sewers in which a flexible pipe is inserted into a main collection sewer. A hole is cut in the pipe at the location of a branch pipe by means of a remotely operated cutter. A flanged rubber line tube is then inserted to seal around the hole and against the inner wall of the branch pipe. This operation for forming the hole after disposing the flexible pipe in the sewer is difficult to achieve. In order to solve these problems, the present inventors have planned a cut-off method in which an impermeable cut-off member is disposed, which the cut-off member has an expandable hose portion and a flange portion provided integrally with one end of the hose portion so that the flange portion is in contact with the inner surface of the first pipeline in liquid tightness and that the hose portion is in contact with the inner surface of the second pipeline and extends within the second pipeline. According to this new cut-off method, there are the advantages that the water leakage from the connection portion is prevented without using any cut-off agent closing the space formed in the connection portion and the water leakage from a portion of the second pipeline is also prevented. In this new cut-off method, however, in case of pipeline having such a size that no operator is able to enter the first and second pipelines, it is difficult to dispose the cut-off member such that the flange portion is positioned within the first pipeline and that the hose portion extends within the second pipeline. SUMMARY OF THE INVENTION An object of the present invention is to provide a cut-off method capable of disposing an impermeable cut-off member, which has an expandable hose portion and a flange portion provided integrally with one end of the hose portion, in a predetermined condition, even in case the pipeline has such a size that no operator is able to enter. The present invention provides a method of water leakage prevention in a portion connecting a first pipeline, having one end and an other end as well as an inner surface and an outer surface, to a second pipeline, having one end in communication with said first pipeline and an other end as well as an inner surface, an outer surface, and an inner diameter, comprising the steps of: passing an elastically deformable elongate member from the other end of the second pipeline to the one end of the first pipeline; engaging an impermeable cut-off member, having an expandable hose portion and a flange portion integrally provided at one end of the hose portion, with said elongate member at the one end of said first pipeline at said hose portion, said hose portion having a length longer than that of said second pipeline; drawing said cut-off member into said first and second pipelines by drawing back said elongate member toward said other end of said second pipeline to dispose said cut-off member in said first and second pipelines, so that the flange portion may be positioned within said first pipeline and the hose portion may extend within said second pipeline; maintaining said flange portion in liquid-tight contact with said inner surface of said first pipeline; disposing an elastically deformable sheet-like base wound in a cylindrical form to be radially expandable within said first pipeline, said base having a hole having a diameter such that a hole formed in said base confronts the opening of the flange portion of the cut-off member, said hole having a diameter approximately equal to the inner diameter of said second pipeline; pressing said flange portion on said inner surface of said first pipeline by means of said base by radially expanding said base, and maintaining said base in a radially expanded state by mutually engaging a plurality of engaging portions provided at said base; and maintaining said hose portion so that said hose portion may be in contact with said inner surface of said second pipeline in order to cover said inner surface of said second pipeline over the entire length of said second pipeline from the inside with said hose portion. According to the present invention, the drawing means which may be made of ropes, wires, steel wires, band steel wires or the like is passed from the side of the other end of the second pipeline to the side of one end of the first pipeline through the first and second pipelines. Then, the hose portion of the cut-off member is engaged with the drawing means at the side of one end of the first pipeline. Under the engaged condition, the drawing means is drawn back toward the other end of the second pipeline. As the cut-off member is drawn from the side of the hose portion into the first and second pipelines in this way, the cut-off member is ultimately disposed in the first and second pipelines so that the flange portion is positioned within the first pipeline and the hose portion extends within the second pipeline. According to the present invention, the cut-off member is drawn from the side of the hose portion into the first and second pipelines by drawing the drawing means extending within the first and second pipelines back toward the other end of the second pipeline. Therefore, the impermeable cut-off member having the expandable hose portion and the flange portion provided intgrally with one end of the hose portion is disposed in a predetermined condition, even though the pipeline has such a size that no operator is able to enter. Elastically deformable first and second elongate members may be used as the drawing means. In this case, the first and second elongate members are respectively inserted into the connection portion from one end of the first pipeline and the other end of the second pipeline, and engaged with each other. The top end of the second elongate member is moved toward one end of the first pipeline by drawing back the first elongate member toward one end of the first pipeline under the condition that both of the elongate members are engaged with each other. After then, the cut-off member is engaged with the top end of the second elongate member. The hose portion of the cut-off member is engaged with the drawing means at the side of one end of the first pipeline by engaging the hose portion of the cut-off member with the first elongate member engaged with the second elongate member. In this case, the cut-off member is disposed in the first and second pipelines by drawing back the second elongate member toward the other end of the second pipeline. The drawing means may be passed from the side of the other end of the second pipeline into the side of one end of the first pipeline by inserting the drawing means into the connection portion from the side of the other end of the second pipeline, by engaging the top end of the drawing means with a carrier disposed movably within the first pipeline, and by moving the carrier toward one end of the first pipeline under the engaging condition. The drawing means may be inserted into the side of one end of the first pipeline from the side of the other end of the second pipeline by inserting the top end of the drawing means into the first pipeline from the side of the other end of the second pipeline, and by moving the top end of the drawing means toward one end of the first pipeline by means of high-pressure fluid jetted from a nozzle disposed movably within the first pipeline. Furthermore, the step of maintaining the cut-off member is carried out so that the flange portion of the cut-off member is in contact with the inner surface of the first pipeline in liquid tightness and that the hose portion extends within the second pipeline. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and features of the invention will become apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings, in which: Fig 1 is a cross-sectional view for explaining a pipeline to be cut off water therefrom according to the present invention; Fig. 2 is a cross-sectional view taken along line 2-2 in Fig. 1; Fig. 3 is a cross-sectional view showing the condition disposing a cut-off member within the pipeline; Fig. 4 is a perspective view showing a cut-off member of a preferred embodiment according to the present invention; Fig. 5 is a enlarged cross-sectional view showing the side of a flange portion of the cut-off member of Fig. 4; Fig. 6 is a perspective view showing a base used with the cut-off member of Fig. 4 as a preferred embodiment according to the present invention; Fig. 7 is a perspective view showing the base of Fig. 6 in its developed condition; Fig. 8 is a cross-sectional view showing the condition of the base transferred into the pipeline together with an expanding machine; Fig. 9 is a cross-sectional view showing the condition of the base expanded within the pipeline; Fig. 10 is a cross-sectional view showing the condition of a deformed projection; Fig. 11 is a view showing another preferred embodiment, in which an elongate member is passed into the pipeline; Fig. 12 is a plan view showing a truck of Fig. 11; Fig. 13 is a view showing a further preferred embodiment, in which the elongate member is passed into the pipeline; Fig. 14 is a plan view showing a truck of Fig. 13; Fig. 15 is a view showing a yet further preferred embodiment, in which the elongate member is passed into the pipeline; Fig. 16 is a plan view showing a truck of Fig. 15; and Fig. 17 is a view showing a still further preferred embodiment, in which the elongate member is passed into the pipeline. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figs. 1 through 3, a portion 10 to be subjected to a cut-off treatment is a portion connecting a first pipeline 12 buried under the ground to a second pipeline 14 branched off from a portion of the first pipeline and extending to over the ground. In an illustrated embodiment, the first pipeline 12 is a main pipe for sewerage and composed of a plurality of pipes connected in series. One end of the first pipeline 12 is communicated with a manhole 16 and the other end is connected to the other manhole (not shown). A first pipe 14 may be a pipe composed of a main pipe already installed and a coating pipe formed at the inside of the main pipe, that is, a repairing pipe portion. The second pipeline 14 is a branch pipe for sewerage and composed of a plurality of pipes connected in series. One end of the second pipeline 14 is communicated with the first pipeline 12, and the other end is communicated with a manhole 18 such as a gully or storm-water inlet. As shown in Figs. 4 and 5, a cut-off member 20 used in the present invention has an expandable hose portion 22 and an elastically deformable flange portion 24 integrally continuous to one end of the hose portion. The hose portion 22 has an outer diameter approximately equal to the inner diameter of the second pipe 14 in which the hose portion is disposed as well as a length longer than the length of the second pipe 14. The hose portion 22 may be made by impregnating an expandable base material, which is formed of fabrics, knittings, sponge-like raw material or the like into a hose shape, with a resin having the property of hardening by heat, light or the like, in particular, ultraviolet ray. The flange portion 24 has an outer diameter larger than the outer diameter of the second pipe 14 as well as a thickness slightly larger than the thickness of the hose portion 22. As shown in Fig. 5, the flange portion 24 is provided with a main portion 26 formed by expanding the end of the hose portion 22 in the radial direction and an auxiliary member 28 mounted on the main portion at the side of the hose portion. The auxiliary member 28 is made of an elastically deformable material such as rubber, and has a plurality of projections 30 provided on its surface at the side of the hose portion 22 and continuously extending around the axis of the hose portion 22. The thickness of the hose portion 22 may be equal with the thickness of the flange portion 24, otherwise, it may be larger than the thickness of the flange portion 24. However, it is preferable that the thickness of the hose portion 22 is made smaller than the thickness of the flange portion 24. The thickness of the hose portion 22, the thickness of the flange portion 24 and the height of the projection 26 may be defined as 0.2 to 5 mm, 1 to 6 mm and 4 to 8 mm respectively, for instance. Furthermore, a sheet-like base 32 shown in Figs. 6 and 7 is used for maintaining the flange portion 24 of the cut-off member 20 under the condition that it is made contact with the inner surface of the first pipe 12 in liquid tightness. The base 32 is made of a metal material such as stainless steel, copper, and copper alloy with corrosion resistance, or a synthetic material such as polyvinyl chloride. The base 32 has an elastically deformable sheet portion 34, a plurality of female engaging portions 36 formed at one end of the sheet portion, a male engaging portion 38 formed at the other end of the sheet portion 34 and capable of engaging with the female engaging portions 36, and a bent portion 40 continuously extending over the longitudinal direction of the sheet portion 34 at both rim portions in the width direction of the sheet portion 34. In the sheet portion 34, a circular hole 42 is formed at the side of the male engaging portion 38 as well as a semicircular notch 44 is formed at the side of the female engaging portion. Both of the hole 42 and the notch 44 have a radius of curvature approximately equal to one half of the inner diameter of the second pipeline 14. A portion 43 defining the hole 42 is bent in the same direction as the bent portion 40. In the illustrated embodiment, the female engaging portion 36 has a tongue struck out by sticking out a portion of the sheet portion 34 toward the opposite side of the bent portion 40, and the male engaging portion 38 is the other end of the sheet portion 34. However, the hole formed in the sheet portion 34 and the projections mounted on the sheet portion 34 or the hole formed in the sheet portion 34 and the Z-shaped metal fitting or the like mounted on the sheet portion 34 may be replaced with any other engaging portions. As shown in Fig. 6, the base 32 is preliminarily wound in a spiral form having a diameter smaller than the inner diameter of the first pipeline 12, that is, in a cylindrical form. In the cylindrically wound condition, the bent portion 40 is directed in the radial outward direction. The base 32 has an inner diameter approximately equal to the inner diameter of the first pipeline 12 under the condition that the male and female engaging portions 36 and 38 are engaged with each other. The axial length of the base 32 is slightly larger than the diameter of the flange portion 24 of the cut-off member 20. The thickness of the base 32 may be defined as 0.5 to 3 mm. At the time of cut-off treatment, first of all, the interiors of the first pipeline 12 and the second pipeline 14 are cleaned. Then, as shown in Fig. 1, first and second elongate members 46 and 48 acting as means for drawing the cut-off member into the first and second pipelines 12 and 14 are respectively inserted into the first and second pipelines 12 and 14 from the manholes 16 and 18. The first and second elongate members 46 and 48 are made of a band-like or rope-like elastically deformable material such as band steel wire and wire rope, and are also wound on reels 46a and 48b installed on the ground, respectively. Subsequently, the top ends of the first and second elongate members 46 and 48 are mutually engaged within the first pipeline 12. It is preferable that a permanent magnet 50 is, for example, mounted on one of the first and second elongate members 46 and 48 to magnetically engage the first and second elongate members with each other by the adsorption force of the permanent magnet. In case of using the permanent magnet 50, the other top ends of the first and second elongate members 46 and 48 are made of a magnetic material. In this manner, the permanent magnet 50 and the other side of the first and second elongate members 46 and 48 drawn near mutually, and therefore, the first and second elongate members 46 and 48 are easily engaged with each other. However, as shown in Fig. 1, a plurality of hook-like engaging portion 52 are formed at one of the first and second elongate members 46 and 48, so that the other of the first and second elongate members may be engaged with the hook like engaging portions. By using of the second elongate member 48 having a top end provided with a chain-like member, the second elongate member 48 may be easily passed through the second pipeline 14. In this case, the chain-like member may be replaced with the engaged portion to be engaged with the hook-like engaging portions. Then, the first elongate member 46 is drawn toward the side of the manhole 16 under the condition that both of the elongate members 46 and 48 are mutually engaged. In this way, the top end of the second elongate member 14 is drawn into the manhole 16. However, the rear end of the second elongate member remains at the outside of the manhole 18. If the second elongate member 48 is drawn toward the side of the manhole 16 in this way, the elongate member 48 may be disposed between the manhole 16 and the other manhole 18 with more security, in comparison with the case the elongate member 48 is pushed into the side of the manhole 16 from the side of the other manhole 18. Then, after the engagement between both of the elongate members are released, the top end of the hose portion 22 of the cut-off member 20 is connected to that of the second elongate member 48 as shown in Fig. 3, and under such a condition, the second elongate member 48 is drawn back to the side of the other manhole 18. The drawing-back of the second elongate member 48 is performed until the flange portion 24 of the cut-off member 20 is brought into contact with the inner surface of the first pipeline 12. In this way, the cut-off member 20 is disposed so that its flange portion 24 may be within the first pipeline 12 and that the hose portion 22 may extend through the second pipeline 14. Before the cut-off member 20 is connected with the second elongate member 48, hardening means such as a heat source and a light source for hardening the cut-off member 20, electric wires for supplying an electric power to the hardening means and a rope for moving the hardening means within the cut-off member are disposed within the cut-off member 20. Therefore, the hardening means, the electric wires and the rope are moved within the second pipeline 14 together with the cut-off member 20, accompanying by the drawing-back of the second elongate member 48. Preferably, the hardening means is disposed in the neighborhood of the flange portion 24 of the cut-off member 20, and the electric wires and the rope are disposed so that they may extend through the hose portion 22 to protrude partially from the top end of the hose portion 22. For instance, the cut-off member 20 may be disposed as mentioned above by moving both of the elongate members 46 and 48 to the side of the manhole 18 under the condition that both of the elongate members 46 and 48 are mutually engaged within the first pipeline 12 and the top end of the hose portion 22 of the cut-off member 20 is connected to the rear end of the first elongate member 46. During each of the preceding operations, it is preferable that a television camera 54 shown in Fig. 1 is disposed within the first pipeline 12 and the preceding operations are confirmed by the television camera. Then, as shown in Fig. 8, the base 32 is disposed at the connection portion within the first pipe 12 together with an expanding machine 56 for expanding the base in the radial direction. The expanding machine 56 is provided with a shaft portion 58, a pair of expansion portions 60 fixed to the shaft portion so as to extend continuously around the shaft portion and expanded like a floating ring by pressure fluid such as compressed air, and a pair of nipples 62 and 64 receiving the pressure fluid through a hose (not shown). The nipple 62 is communicated with both of the expansion portions 60 through a flow path (not shown), and the nipple 64 is communicated with an opening 66 located between both of the expansion portions 60 and formed in the shaft portion 58 through a flow path (not shown). As for this kind of the expanding machine 56, a water-sealing machine under the trade name of "PACKER" manufactured by Toa Grout Kogyo Kabushiki Kaisha, which is one of the applicants for the patent in the present invention, may be used. The expanding machine 56 is disposed within the base 32 with the expansion portion 60 shrunken. Subsequently, the expanding machine 56 is moved to a predetermined position within the first pipeline 12 together with the base 32 under the condition that the expansion portions 60 are radially expanded the pressure fluid supplied from a fluid source installed on the ground to the nipple 62 through a hose to such an extent as the base 32 may not displace against the expanding machine 56. The base 32 and the expanding machine 56 are related to each other so that the center of the hole 42 in the base 32 may be placed between both of the expansion portions 60 of the expanding machine 56. For instance, in case the first pipeline 12 is in such a size that any operator cannot enter, the base 32 and the expanding machine 56 may be moved to a predetermined position within the first pipeline 12 by passing a rope through from one end to the other end of the first pipe 12, connecting the rope to the expanding machine 56 at the side of the other end of the first pipe 12, and moving the rope to the side of the one end of the first pipe 12 by a predetermined distance. When the expanding machine 56 is moved, it is preferable that the base 32 and the expanding machine 56 are moved by mounting a television camera on the expanding machine 56 and monitoring the picture image through the television camera. As shown in Fig. 8, a recess 68 for receiving therein the flange portion 24 of the cut-off member 20 and the base 32 is formed on the inner surface of the first pipeline 12. The recess 68 is formed before the first and second elongate members 46 and 48 are respectively inserted into the first and second pipelines 12 and 14. When the base 32 and the expanding machine 56 are moved to the position where the hole 42 of the base 32 confronts the opening of the flange portion 24 of the cut-off member 20, the pressure fluid is supplied to the nipple 62 of the expanding machine 56, and the expansion portions 60 are further expanded in the radial direction. According to this procedure, the base 32 is expanded in the radial direction to such a degree that both ends of the sheet portion 34 slightly overlap with each other, that is, to such a degree that the male engaging portion 38 is made engageable with either of the female engaging portions 36. As a result, the projections 30 of the cut-off member 20 are pressed by the sheet portion 34 as shown in Fig. 9 against the inner surface of the first pipeline 12, so that the projections 30 are elastically deformed as shown in Fig. 10. Then, the pressure fluid within the expansion portion 60 is removed until the male engaging portion 38 is engaged with either of the female engaging portions 36 by the restoring force of the projections 30, and so the base 32 is shrunken. As a result, the projections 30 are maintained under the condition that the projections are pressed by the base 32 against the inner surface of the first pipe 12, and airtightness between the inner surface of the first pipe 12 and the flange portion 24 and that between the flange portion 24 and the base 32 are maintained, respectively. Subsequently, the pressure fluid is supplied to the nipple 64 of the expanding machine 56 under the condition that the cut-off member 20 is maintained so as to extend through the second pipeline 14, the top end of the hose portion 22 is closed in airtightness and further the airtightness between the expansion portion 60 and the base 32 is maintained. Since the pressure fluid is supplied from the opening 66 of the shaft portion 58 into the cut-off member 20 in this manner, the cut-off member 20 is expanded in the radial direction so that the hose portion 22 may come into contact with the inner surface of the second pipeline 14. Then, the cut-off member 20 is hardened by the hardening means under the condition that the cut-off member 20 is expanded. This operation is performed by moving the hardening means 70 preliminarily disposed within the cut-off member 20 as shown in Fig. 9 toward the hose portion 22 within the cut-off member 20 at least one time, while generating heat, light, in particular, ultraviolet ray by feeding electric power to the hardening means 70. The hardening means 70 may be moved by use of the rope preliminarily disposed at the cut-off member 20 together with the hardening means 70. Then, after the pressure fluid within the expansion portion 60 is removed, the expanding machine 56 is removed. The top end of the cut-off member 20 is also opened, the hardening means 70 is removed from the opened top end, and the top end of the cut-off member 20 is fixed to the manhole 18. Since the base 32 is maintained under the condition that the male engaging portion 38 is engaged with either of the female engaging portions 36 by the restoring force of the projections 30, the flange portion 24 is maintained to be pressed by the base 32 against the inner surface of the first pipe 12 and the airtightness between the inner surface of the first pipe 12 and the flange portion 24 and that between the flange portion 24 and the base 32 are maintained. As a result, the leakage of water from the connection portion is prevented and the leakage of water from a portion of the second pipeline 14 is also prevented. The cut-off member 20 may be expanded into a predetermined form by supplying the pressure fluid to the hose portion 22 from the side of its top end. As mentioned above, the cut-off member 20 may be disposed within the first and second pipelines 12 and 14 by drawing back the second elongate member 48 toward the manhole 18 together with the first elongate member 46 under the condition that the cut-off member 20 is engaged rear end of the first elongate member 46. Instead of using the first and second elongate members as means for drawing the cut-off member into the first and second pipelines, one elongate member may be used. In this case, the elongate member is passed from the side of the manhole 18 into the other manhole 16 through the second pipeline 14, the portion connecting the pipeline 12 to the pipeline 14 and the first pipeline 12. In the case of using one elongate member as drawing means, the elongate member passed from the manhole 18 into the first pipeline 12 through the second pipeline 14 may be passed from the manhole 18 into the other manhole 16 through both of the pipelines by engaging the top end of the elongate member with a truck disposed in the first pipeline so as to be movable within the first pipeline and moving the truck toward one end of the first pipeline in such a condition. A carrier or truck 72 shown in Figs. 11 and 12 is mounted with a television camera 74 and has also a Y-shaped hook 76 projecting forwards. The elongate member 48 passed from the manhole 18 to the first pipeline 12 through the second pipeline 14 has a spherical engaged portion 78, which is engaged with a hook 76, at its top end. The truck 72 travels by itself within the first pipeline 12 toward the manhole 16 shown in Fig. 1 under the condition that the engaged portion 78 of the elongate member 48 is engaged with the hook 76. In this way, the elongate member 48 is passed into both of the pipelines 12 and 14. A carrier or truck 80 shown in Figs. 13 and 14 has a permanent magnet 82 instead of the hook 76. The elongate member 48 passed from the manhole 18 to the first pipeline 12 through the second pipeline 14 has a magnetic body 84 at its top end. The truck 80 travels by itself within the first pipeline 12 toward the manhole 16 shown in Fig. 1 under the condition that the magnetic body 84 of the elongate member 48 passed from the manhole 18 to the first pipeline 12 through the second pipeline 14 is magnetically engaged with the permanent magnet by adsorbing the magnetic body 84 to the permanent magnet. In this way, the elongate member 48 is passed into both of the pipelines 12 and 14. A carrier or truck 86 shown in Figs. 15 and 16 has a vacuum adsorption plate 88 instead of the hook 76. The elongate member 48 passed from the manhole 18 to the first pipeline 12 through the second pipeline 14 has a cloth-like thin and soft adsorbed member 90 at its top end. The vacuum adsorption plate 88 is connected to a vacuum pump (not shown). The truck 80 travels by itself within the first pipeline 12 toward the manhole 16 shown in Fig. 1 under the condition that the adsorbed member 90 is vacuumizingly engaged with the vacuum adsorption plate 88 by sucking the adsorbed member 90 on the vacuum adsorption plate 88. In addition to the above-mentioned embodiments, for example, as shown in Fig. 17, the elongate member 48 may be flown down to the manhole 16 shown in Fig. 1 by high-pressure water 94 jetted from a nozzle 92 disposed in the first pipeline 12. The nozzle 92 is connected to a high-pressure supply source (not shown) through a hose 96. Further, the nozzle 92 is moved within the first pipeline 12 by means of a rope (not shown) or the like when flowing down the elongate member 48. The elongate member 48 has a cloth-like thin and soft member 96 for receiving the high-pressure water 94 at its top end. The present invention is suitable to the water cut-off method of the pipeline of such a size as any operator is not able to enter, while it is also applied to that of the pipeline of such a size as any operator is able to enter. The present invention is also applied to the cut-off of water from the portion connecting the pipelines together other than sewerage pipelines, for example, the portion connecting the main pipe in a pipeline for power line or telephone line, i.e., the first pipeline to its branch pipe, i.e., the second pipeline.

Claims: A method of water leakage prevention in a portion connecting a first pipeline (12), having one end and an other end as well as an inner surface and an outer surface, to a second pipeline (14), having one end in communication with said first pipeline and an other end as well as an inner surface, and outer surface, and an inner diameter, comprising the steps of: passing an elastically deformable elongate member (48) from the other end of the second pipeline (14) to the one end of the first pipeline (12); engaging an impermeable cut-off member (20), having an expandable hose portion (22) and a flange portion (24) integrally provided at one end of the hose portion, with said elongate member (48) at the one end of said first pipeline (12) at said hose portion, said hose portion 22 having a length longer than that of said second pipeline (14); drawing said cut-off member (20) into said first and second pipelines (12,14) by drawing back said elongate member (48) toward said other end of said second pipeline (14) to dispose said cut-off member (20) in said first and second pipelines (12,14), so that the flange portion (24) may be positioned within said first pipeline (12) and the hose portion (22) may extend within said second pipeline (14); maintaining said flange portion (24) in liquid-tight contact with said inner surface of said first pipeline (12); disposing an elastically deformable sheet-like base (32) wound in a cylindrical form to be radially expandable within said first pipeline (12), said base (32) having a hole having a diameter such that a hole (42) formed in said base confronts the opening of the flange portion (24) of the cut-off member (20), said hole (42) having a diameter approximately equal to the inner diameter of said second pipeline (14); pressing said flange portion (24) on said inner surface of said first pipeline (12) by means of said base (32) by radially expanding said base, and maintaining said base (32) in a radially expanded state by mutually engaging a plurality of engaging portions (36,38) provided at said base (32); and maintaining said hose portion (22) so that said hose portion (22) may be in contact with said inner surface of said second pipeline (14) in order to cover said inner surface of said second pipeline (14) over the entire length of said second pipeline (14) from the inside with said hose portion (22). A method according to claim 1, characterised by further comprising the step of forming in the inner surface of said first pipeline (12) a recess (68) for disposing at least said flange portion (24) and said base (32), prior to disposing said cut-off member (26). A method according to claim 2, characterised in that said recess (68) has a width and a bottom surface and said base (32) has a width smaller than that of said recess (68), and wherein said flange portion (24) is maintained in liquid-tight contact with the bottom surface of said recess (68) by the step of maintaining said base (32) in the radially expanded state. A method according to claim 3, characterised in that said flange portion (24) has a diameter smaller than the width of said recess (68).

Inventors: KITAJIMA HISASHI, NODA HIDEHIRO, KITAJIMA, HISASHI, NODA, HIDEHIRO
Applicants: ISEKI KAIHATSU KOKI, TOA GROUT KOGYO CO, KABUSHIKI KAISHA ISEKI KAIHATSU KOKI, TOA GROUT KOGYO KABUSHIKI KAISHA
Application year: 1991
Main classification: F16L55
IPC codes: F16L55, H02G1