Patent ID: 6149349
Filing Date: 2000-11-21
Classification: E02F,E21B

Abstract:
A method for extracting an old pipe buried in the ground, comprising:(a) providing a mobile excavator which has a movable boom having a tool end, said tool end having means for quick connection with an excavating bucket;(b) connecting the excavating bucket to the tool end;(c) digging a first pit in the ground with the excavator and excavating bucket to expose and make accessible a first end of the old pipe;(d) digging a second pit in the ground with the excavator and excavating bucket so as to expose and make accessible a second end of the old pipe;(e) inserting a segmented extraction cable formed of disengageable sections, said cable having a pulling end and a pulled end, through the old pipe and securing an abutment member to the pulled end for abutting the abutment member against the second end of the old pipe, whereby the pulling end of the extraction cable remains protruding from the first end of the old pipe;(f) disconnecting the excavating bucket from the tool end and connecting a frame to the tool end, the frame having means for quick connection with the tool end quick connection means, said frame having a a hydraulic cylinder actuator mounted therein and a reaction plate structure;(g) using the excavator boom to position the frame into the first pit with the hydraulic cylinder actuator aligned with the old pipe;(h) arresting movement of the boom so as to substantially prevent movement of the tool end relative to the mobile excavator;(i) connecting the actuator to the pulling end of the extraction cable extending from the first end of the old pipe;(j) using a hydraulic system of the excavator to operate the hydraulic cylinder actuator to pull on the extraction cable to induce the abutment member and the pulled end of the extraction cable to bias the old pipe through the ground while the frame is supported against reaction forces firstly by the reaction plate structure bearing against the pit wall and secondly by the boom preventing twisting.