Knife holder for cutting machines

A knife holder assembly for cutting machines, the knife holder assembly comprising:

• a cutter head (1) for holding a knife (2);
• and
• a positioning device (3), wherein the positioning device (3) comprises:
• a piston apparatus (7) configured to drive the knife a drive direction (4) between a standby position and a cutting position, and
• a spring (5), wherein the spring applies a reset force against the piston apparatus while the knife is in the cutting position,
• wherein the spring (5) generates the reset force having a negative force characteristic curve in the drive direction (4), such that the reset force generated by the spring acting transversely to a longitudinal axis of the spring and against the piston apparatus (7) diminishes with an increasing travel distance in the drive direction (4) from the standby position to the cutting position and
• wherein the longitudinal axis of the spring (5) is aligned at an angle (6) of 30° to 80° relative to the drive direction (4) when the knife is in the standby position.