Device and system for opening up branch point of pipe assembly

A system for opening up a branch point in a pipe assembly, comprising:

• a power transmission assembly comprising a protecting tube, a flexible rotation axle which is stiff in thrust and runs at least partly inside the protecting tube, and a motor for rotating the rotation axle,
• the system additionally comprises a device, the device comprising:
• a rotation axle arranged to be rotatable and a tip part arranged to be rotatable and in connection of which there is at least one blade, as well as a centralizing system separate from the tip part and arranged to be substantially non-rotating when the tip part is rotated, and which the centralizing system comprises at least two discs through which the rotation axle is arranged to pass, and a tube that keeps the discs apart,
• the centralizing system additionally comprising at least one spring which presses said at least two discs and at least one tube against each other to position the discs as planes perpendicular to the rotation axle;
• and
• the device being arranged to be mounted to the rotation axle of said power transmission assembly, said device being pushable to the branch point to be opened up in the pipe assembly by means of the protecting tube of the power transmission assembly and the rotation axle, and said branch point being operable by transforming the rotary motion of the motor into rotary motion of the tip part of the device and by pushing the device against the branch point;
• and
• each disc being movable between a first position wherein the disc is perpendicular relative to the rotation axle and a second angled position wherein an upper side-edge on one side of the disc is moved away from an inner wall of a pipe while a lower side-edge on a diametrically opposite side of the disc is also moved away from the inner wall of the pipe.