Method of drilling a branch line aperture after internal lining of a pipeline and a water plug used in the method

Claim 1

A method of drilling apertures for branch lines blocked by renovation lining of a main pipeline having branch lines which is characterized by a plug mounting step for setting a water plug in each of openings of said branch lines, said water plug carrying a position marker comprising an antenna coil and a resonator adapted to oscillate in response to a driving signal and, after stoppage of said driving signal, release a resonance signal remaining in said resonator from said antenna coil and said position marker being situated, upon setting of said water plug in position, in substantially concentric relation with the axis of the branch line, a marker detecting step which comprises causing an antenna assembly for detecting said resonance signal to travel within the main pipeline to detect the position of said marker, and an aperture drilling step which comprises driving a drilling means using said marker position as a target to drill an aperture for said branch line from within the main pipeline.

Claim 2

A method of drilling apertures for branch lines blocked by renovation lining of a main pipeline having branch lines which is characterized by a plug mounting step for setting a water plug in each of openings of said branch lines, said water plug carrying a position marker comprising an antenna coil and a resonator adapted to oscillate in response to a driving signal and, after stoppage of said driving signal, release a resonance signal remaining in said resonator from said antenna coil and said position marker being situated, upon setting of said water plug in position, in substantially concentric relation with the axis of the branch line, a marker detecting step which comprises causing an antenna assembly for detecting said resonance signal to travel within the main pipeline to detect the position of said marker, and an aperture drilling step which comprises driving a drilling means using said marker position as a target to drill an aperture for said branch line from within the main pipeline.

Claim 7

A method of drilling apertures for branch lines blocked by renovation lining of a main pipeline having branch lines which is characterized by setting a water plug in the opening of each branch line prior to said lining, said water plug carrying a position marker which includes an antenna coil and a resonator adapted to oscillate in response to a driving signal and, after stoppage of said driving signal, releases a resonance signal remaining in said resonator from said antenna coil, said position marker being situated, upon setting of said water plug in position, in substantially concentric relation with the axis of the branch line, and where the opening of branch lines are closely adjacent to each other, water plugs carrying position markers dessimilar in the frequency of resonance signal being set in the adjacent branch line openings, causing an antenna assembly having a loop antenna for detecting the maximal value of said resonance signal in a position where its loop plane is parallel to the axis of said main pipeline to travel within the main pipeline after said lining, tuning the reception frequency of said loop antenna to the frequency of the resonance signal from one of the plurality of position markers to detect the resonance signal from said marker and also detect the maximum value of said resonance signal to find the position of the particular markers, actuating a drilling means using the thus-detected position of said marker as a target to drill an aperture for the corresponding branch line from within the main pipe, repeating the same procedure of detecting resonance signals and their maximum values from position markers of water plugs set in the remaining branch line openings to identify the positions of the respective position markers and drill apertures for the respective branch lines with said drilling means using the detected positions of the respective markers as targets.

Claim 8

A method of drilling apertures for branch lines blocked by renovation lining of a main pipeline having branch lines which is characterized by setting a water plug in the opening of each branch line prior to said lining, said water plug carrying a position marker which includes an antenna coil and a resonator adapted to oscillate in response to a driving signal and, after stoppage of said driving signal, releases a resonance signal remaining in said resonator from said antenna coil, said position marker being situated, upon setting of said water plug in position, in substantially concentric relation with the axis of the branch line, and where the opening of branch lines are closely adjacent to each other, water plugs carrying position markers dessimilar in the frequency of resonance signal being set in the adjacent branch line openings, causing an antenna assembly having a loop antenna for detecting the maximal value of said resonance signal in a position where its loop plane is parallel to the axis of said main pipeline to travel within the main pipeline after said lining, tuning the reception frequency of said loop antenna to the frequency of the resonance signal from one of the plurality of position markers to detect the resonance signal from said marker and also detect the maximum value of said resonance signal to find the position of the particular markers, actuating a drilling means using the thus-detected position of said marker as a target to drill an aperture for the corresponding branch line from within the main pipe, repeating the same procedure of detecting resonance signals and their maximum values from position markers of water plugs set in the remaining branch line openings to identify the positions of the respective position markers and drill apertures for the respective branch lines with said drilling means using the detected positions of the respective markers as targets.