Electric cutting tool with automatic emergency stop

Safety cutting tool comprising:

• an electrically conductive cutting element;
• an electrically controlled actuating motor (20) of the cutting element;
• a gripping handle of the cutting tool for the hand of an operator, the gripping handle being electrically insulated from the cutting element;
• a cutting trigger control activated by the hand of the operator grasping the gripping handle, the cutting trigger control being electrically insulated from the cutting element;
• an emergency stop device responsive to an operator's contact with the cutting element, characterized by:
• at least one first and at least one second manual contact electrode, the first manual contact electrode and the second manual contact electrode being electrically insulated from each other, and positioned on at least either the gripping handle of the tool or the cutting trigger control so as to be touched simultaneously by the operator's hand when he grasps the gripping handle;
• an electric monitoring circuit including the first manual contact electrode and the cutting element, the electric monitoring circuit is capable of closing upon a simultaneous contact of the operator with said first manual contact electrode and with the cutting element;
• an electric generator of a monitoring current in the first electric circuit;
• a measuring device of a monitoring voltage between the cutting element and the second manual contact electrode;
• a comparator of at least one monitoring electrical characteristic dependent on the monitoring voltage and a threshold electrical characteristic dependent on an impedance value which increases the human body conduction impedance value, the comparator being connected to the emergency stop device of the actuating motor of the cutting element, to cause an emergency stop when the monitoring electrical characteristic crosses the threshold electrical characteristic.