Method and apparatus for opening an envelope

摘要

An envelope (23) to be opened is moved along a tangent line to a rotating, circular cutting edge (2), with the cutting edge (2) making an incision in a wall of the envelope (23). The envelope (23) is moved at a predetermined speed of transport which is different from the speed of revolution of the cutting edge (2). The cutting edge (2) moves in longitudinal direction along the material to be incised, so that a better cutting action is obtained. Each part of the material to be incised comes into contact with a large part of the cutting edge (2). As a result, the cutting action and the depth of incision are little affected by unroundness and eccentricity of the cutting edge (2). The cutting edge (2) wears uniformly because parts of the cutting edge (2) wear faster according as they project further from the axis of rotation (3). Also disclosed is an apparatus for practising this method. <IMAGE>