| 摘要 |
PCT No. PCT/FI95/00325 Sec. 371 Date Dec. 9, 1996 Sec. 102(e) Date Dec. 9, 1996 PCT Filed Jun. 7, 1995 PCT Pub. No. WO95/33591 PCT Pub. Date Dec. 14, 1995An apparatus and method for making an elongated hole in a pipe which includes drilling a rotating conical tool through the pipe wall by pushing the conical tool in the direction of its rotating axis to a desired depth, then simultaneously lifting and tilting the conical bit so as to mill one end of an elongated hole. The rotatable conical tool may be lifted and tilted in the opposite direction to further mill the pipe and elongate the hole. Tilting is effected relative to a pivot point located above the top pipe surface and in a plane extending through a center axis of the pipe, and the angle of inclination can be adjusted for determining the length of the finished hole. |
