| 摘要 |
PCT No. PCT/NO93/00180 Sec. 371 Date May 30, 1995 Sec. 102(e) Date May 30, 1995 PCT Filed Nov. 30, 1993 PCT Pub. No. WO94/12827 PCT Pub. Date Jun. 9, 1994A pipe tractor is adapted to run internally in channels and pipes in that the pipe tractor's end pieces are counterrotating and provided with resilient arms to which are attached inclined wheels resting against the inner surface of the pipe, wherein lateral force acting on the wheels gives propulsion to the pipe tractor when the end pieces rotate. |
