Method for binding a connecting pipe to a principal pipe which has been reconstructed with a relining pipe of plastic material

A method for binding a connecting pipe to a principal pipe which has been reconstructed with a relining pipe of plastic material comprises determining the mid-point of the opening in the principal pipe located in the proximity of that end of the connecting pipe pointing toward the principal pipe, producing an opening in the relining pipe in the region of the mid-point by heating the plastic material from the interior of the relining pipe and proceeding toward the exterior, widening the produced opening by simultaneously exerting pressure on the inside of the relining pipe in the direction toward the connecting pipe and heating the region of the plastic material on which pressure is being applied to form a collar around the widened opening, applying the plastic material of the collar projecting into the connecting pipe to the inside of the end of the connecting pipe adjacent the principal pipe, fastening the collar of the plastic material to the inside of the connecting pipe and then further flattening and fastening the collar of the plastic material to the inside of the connecting pipe.

BACKGROUND OF THE INVENTION
 The present invention is directed to a method for binding a connecting pipe
 to a principal pipe which has been reconstructed with a relining pipe of
 plastic material.
 When a connecting pipe is no longer connected leak-free to a main pipe, for
 example due to slumping, the main pipe is reconstructed by inserting a
 relining pipe of plastic into the main pipe. Subsequently, the connecting
 pipe is reconnected to the reconstructed main pipe. To this end, it is
 necessary that an opening be produced in the relining pipe in the region
 of a tap opening located in the proximity of that end of the connecting
 pipe pointing toward the main pipe. In the prior art, this occurs by
 milling, cutting, welding or with lasers. All of the above-mentioned
 opening methods, however, exhibit the following disadvantages:
 i) Tools that must be repeatedly reconditioned are required for forming the
 opening.
 ii) No seepage-free connection between the main pipe and the connecting
 pipe is possible.
 iii) The ground water is jeopardized even more by gap formations between
 the main pipe and the connecting pipe.
 iv) Considerable damage can be caused given an incorrect measuring or,
 respectively, tap openings that are not 100% localized. This then requires
 access and, thus, causes considerable costs.
 v) Only certain cross-sectional sizes can be opened.
 SUMMARY OF THE INVENTION
 The present invention is based on the object of providing a method for
 optimum binding of a connecting pipe to a principal pipe.
 This object is achieved by a method of binding a connecting pipe to a
 principal pipe which has been reconstructed with a relining pipe of
 plastic material, said method comprising the steps of localizing or
 determining the mid-point of the opening in a principal pipe located in
 the proximity of the end of the connecting pipe pointing toward the
 principal pipe, said determining or locating being from the inside of a
 relining pipe; producing an opening in the relining pipe in the region of
 the localized mid-point by heating the plastic material of the relining
 pipe located in said region proceeding from the inside of the relining
 pipe; widening the opening by simultaneously exerting pressure on the
 inside of the relining pipe in the direction toward the connecting pipe
 and heating the region of the plastic material on which the pressure is
 exerted from the inside of the relining pipe toward the connecting pipe to
 form a projecting portion which extends into the connecting pipe; applying
 the projecting portion of the plastic material of the relining pipe to the
 inside of that end of the connecting pipe pointing toward the principle
 pipe; fastening the plastic material of the projecting portion to the
 inside of the connecting pipe and flattening the plastic material of the
 projecting portion as it is fastened to the inside of the connecting pipe.
 In particular, it can thereby be provided that the mid-point is localized
 or determined either with ultrasound or sonar technology.
 The heating temperature for producing an opening is preferably selected
 dependent on the nature of the material. Beneficially, the heating
 temperature for widening the opening is selected dependent on the nature
 of the plastic material.
 It can also be provided that the opening is widened into either a round
 opening or an oval opening.
 Advantageously, the projecting portion of the plastic material projecting
 into the connecting pipe is applied beginning at that end of the
 connecting pipe pointing toward the principal pipe. Then the material is
 progressively formed against the inside of the connecting pipe inward of
 that end.
 In another particular embodiment of the invention, it can be provided that
 the projecting portion of the plastic material is secured to the inside of
 the connecting pipe by applying-glue or by welding the plastic material
 thereto.
 Beneficially, the end of the projecting portion of the plastic material
 extending into the connecting pipe is flattened by heating. It can also be
 provided that the end of the projecting portion of the plastic material
 can be flattened by stretching. In both cases, the flattening can cause a
 tapering or thinning of the material at the end of the projecting portion.
 Finally, it can be provided that the shaping of the connection is monitored
 by a semi-electronic method or a semi-mechanical method. Included within
 what is to be understood as shaping is the cross-sectional shape of the
 connection, for example oval or round, and the angle of the projecting
 portion relative to the principal pipe.
 The invention is based on the surprising perception that the plastic
 material of the relining pipe that must normally be removed for producing
 an opening to the connecting pipe can be employed for producing a
 seepage-free connection between the principal pipe and the connecting or
 branch pipe. This means that an optimum connection can be realized without
 additional material. The shape of the connection as well as the entry
 angle are thereby not impediments to forming the connection. Moreover, all
 types of plastic can be processed. Over and above this, there is no damage
 to the principal pipe or the carrier pipe.
 Other advantages and features of the invention will be readily apparent
 from the following description of the preferred embodiments, the drawings
 and claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
 As illustrated in FIG. 1, a principal pipe 18 is provided with a lining or
 relining pipe 19 of a plastic material. A displacement means 11 is
 introduced into the interior of the principal pipe within the relining
 pipe 19 and is provided with a localization means 10 and a working head
 12. Alternatively, the working head 12 could also be located on a probe.
 The localization means 10 can, for example, comprise an ultrasound device
 or sonar device. Dependent on its size, for example, a working head can
 have more than 2-10 heating devices (not shown) provided thereon.
 In FIGS. 2-6, for the sake of clarity, the displacement means 11 has been
 omitted and the localization means 10 and the working head 12 have not
 been shown true-to-scale. The working head 12 comprises a plate 12a on
 which three fingers 12b are arranged in the present embodiment. These
 fingers are pivotable and spaced on pivot points due to the action of
 hydraulic cylinders 20, with two cylinders arranged for each finger. Over
 and above this, the fingers 12b are displaceable in a radial direction due
 to the displaceability of the hydraulic cylinders 20, which can pivot on
 the plate 12a. The working head 12 is rotatable by 360.degree. around an
 x-axis and by 120.degree. around a y-axis in common with the localization
 means 10. As a result thereof, the plastic material of the relining pipe
 19 can be continuously shaped into the desired shape with respect to the
 inside of a connecting pipe 16.
 One or more heating devices 14 are located in the tip of each of the
 fingers 12b. In addition, additional heating devices 24 (see FIG. 5) for
 melting the plastic material of the relining pipe 19 are located along the
 fingers 12b, dependent on the required amount of heat, and these are
 omitted from FIGS. 2-4 for the sake of clarity.
 In FIG. 2, the localization means 10 is used for locating or determining
 the mid-point of an opening 15, which is located in the proximity of the
 end of the connecting or branch pipe 16 pointing toward the principal pipe
 18. The working head 12 together with the localization means 10 is
 advanced in the direction of the connecting pipe 16 between the method
 steps shown in FIGS. 2 and 3, which will result in the heating device 14
 touching the plastic material of the relining pipe 19 in the region around
 the localized mid-point of the opening 15 to melt the plastic material.
 The opening which is produced is widened in FIG. 3 by further heating
 devices 24 (see FIG. 5), which heating devices 24 are preferably in the
 form of thermal elements. Further advancing of the working head 12 in
 common with the localization means 10 into the connecting pipe 16 will
 result in a pressure being exerted onto the inside of the relining pipe 19
 to form an annular collar or flange 22 around the widened opening.
 In FIG. 4, the annular collar or flange of the plastic material of the
 relining pipe 19 projects into the connecting pipe 16 and is applied to
 the inside of that end of the connecting pipe 16 pointing toward the
 principal pipe by moving of the outer fingers 12b radially outward and by
 rotation of the head 12.
 In FIG. 5, the collar or portion of the plastic material of the relining
 pipe 19 which projects into the connecting pipe 16 is secured in
 punctiform fashion at points 28 to the interior of the connecting pipe 16
 by the punctiform heating with the heating devices 24. The fastening is
 undertaken, first, at a location situated at the left of FIG. 5.
 In FIG. 6, finally, the end of the flange or collar of the plastic material
 is flattened by heating with the heating devices 14 and is secured to the
 inside of the connecting pipe 16. This flattening causes the end to have a
 tapering configuration.
 A suitable mechanism can also be employed instead of the hydraulic
 cylinders 20. For processing, which includes melting or shaping various
 plastic materials, the temperature in the working head 12 is matched to
 the respective plastic material. The monitoring of the shaping of the
 connection can be achieved with sensors in a semi-electronic or
 semi-mechanical way. Both oval as well as round openings can be opened.
 Likewise, openings having entry angles deviating from 90.degree. angles
 can be opened.
 A seepage of harmful substances into the ground is prevented by the
 flattening and fastening of the end of the annular flange or collar of the
 plastic material of the relining pipe 19 to the interior of the connecting
 pipe 16. In addition, the thickness of the applied plastic material can be
 modified, for example be reduced, by stretching during the processing
 event.
 Although various minor modifications may be suggested by those versed in
 the art, it should be understood that we wish to embody within the scope
 of the patent granted hereon all such modifications as reasonably and
 properly come within the scope of our contribution to the art.