Blade holder having displacement-dependent spring force compensation

A blade holder for a cutting machine, comprising:

• a blade head held on a raising and lowering device, wherein said blade head is provided with a circular blade;
• an adjustment mechanism for said circular blade, wherein for a movement of said circular blade between a cutting position and a ready position, said adjustment mechanism is provided with an adjustment piston rod having an adjustment piston that is guided in a chamber of a housing of said blade head and that is adapted to be moved by compressed air, and wherein a piston surface of said adjustment piston that is effective in a direction of adjustment has a cross-sectional area that is different in different positions of said adjustment piston such that as a path of said adjustment piston in said direction of adjustment increases, said piston surface that is acted upon by compressed air increases, wherein said adjustment piston is provided with at least one extension, wherein a peripheral surface of the at least one extension slidingly engages an inner, axially extending surface of the housing;
• and
• a compression spring for biasing said adjustment piston rod into said ready position of said circular blade.