Portable boring machine

A portable boring machine comprising:

• a transmission unit comprising a first electric motor imparting rotation about a first axis of rotation (B) and a distribution block configured to distribute said rotation imparted by said first electric motor to a tools shaft, wherein said tools shaft supports means for boring and welding and has a second axis of rotation (C) extending there through;
• a centralized unit which includes,
• a supporting shaft for advancement of said tools shaft, the supporting shaft being formed by a hollow cylindrical tube having an externally threaded screw tube contained therein, and
• a centralized second electric motor adapted to manage said advancement;
• means for coupling and decoupling said transmission unit from said centralized unit;
• and
• an advancement system configured to advance said screw tube and convert rotary motion imparted by said second electric motor into straight linear motion of said screw tube along said second axis of rotation (C), wherein said advancement system includes,
• at least one element fixed to said supporting shaft;
• at least one threaded dowel movable inside said supporting shaft;
• at least one spring positioned in said at least one element and acting on said at least one threaded dowel;
• and
• at least one lever element hinged to a pin passing through said at least one threaded dowel, the at least one lever element being movable from a central position P to a right angular position D and to a left angular position S.