Cutting device for a roll of protective film

A cutting positioning unit comprising:

• a positioning unit having two aligned and elongated vertical side walls, an elongated horizontal top wall which interconnects top ends of said side walls so as to define an elongated sliding space between said side walls and under said top wall, and a longitudinally extending slot formed through said top wall and communicated with said sliding space;
• and a cutter including a sliding body which is placed on a top surface of said top wall of said positioning unit, said sliding body having a rear portion and a front portion which has a rearwardly and downwardly inclined front end surface and a notch formed in a bottom surface thereof, said cutter further including a blade which is mounted securely on said sliding body in said notch and which extends rearwardly and downwardly from said sliding body in such a manner that a cutting edge of said blade is aligned with said front end surface of said front portion of said sliding body, and a guide unit which includes two vertical plates that project downwardly from the bottom surface of said rear portion of said sliding body through said slot of said top wall of said positioning unit, and two horizontal plates that project respectively and outwardly from lower ends of said vertical plates under said top wall of said positioning unit, said slot of said top wall of said positioning unit being sized so as to prevent removal of said guide unit from said positioning unit, said vertical plates having a length longer than a thickness of said top wall of said positioning unit so that, when said cutting edge of said blade contacts a material to be cut said front portion of said sliding body is capable of turning upwardly so as to facilitate cutting of the material by said cutting edge of said blade;
• said sliding body having a curved concave portion in the bottom surface thereof between said blade and said guide unit so as to prevent contact between said bottom surface of said sliding body and a portion of said material which has been cut-off.