Electric knife

An electric knife, comprising a cutter blade, a handle, and a drive unit and a driven unit mounted inside said handle, wherein:

• said drive unit comprises a motor with an output shaft, a screw set in said output shaft of said motor and rotatable with said output shaft, said screw comprising two threads in opposite directions, a first movable sleeve set on said screw, said first movable sleeve having two opposite sides thereof respectively provided with a perforation, a first fixed sleeve fixed inside said handle and sleeved outside said first movable sleeve, said first fixed sleeve having two opposite sides thereof respectively provided with a long guide groove corresponding to the two perforations of said first movable sleeve, two rolling members respectively located on one side of said two threads of said screw and rollable along the respective said threads, each said rolling member having one side thereof attached to the associating said thread of said screw and an opposite side thereof protruding out of said first movable sleeve through one respective said perforation of said first movable sleeve, and the protruding part of each said rolling member being limited in the respective said long guide groove of said first fixed sleeve;
• said driven unit comprises a cutter blade holder holding one end of said cutter blade and a second movable sleeve sleeved on said cutter blade holder and fixed with said cutter blade holder, said second movable sleeve and said first movable sleeve being pivotally connected with a link, so that said second movable sleeve is drivable by said first movable sleeve.