Three-knife trimmer

Apparatus for trimming edges of a stack of papers positioned upon a cutting table comprising:

• side knife means, said side knife means including at least a first cutting blade having a linear cutting edge;
• front knife means said front knife means including a second cutting blade having a cutting edge oriented transversely with respect to the cutting edge of said first cutting blade;
• first moveable support means for said side knife means;
• second moveable support means for said front knife means;
• first drive means, said first drive means causing said first support means to move in a first direction from a starting position whereby said side knife means is brought into contact with the stack of paper to produce the desired trimming of at least one side edge thereof, said first drive means further causing said first support means to move in a second direction after the desired trimming is produced, whereby said side knife means is returned to its starting position, said first and second directions following a multi-directional orbital path;
• and
• second drive means, said second drive means causing said second support means to move in a direction whereby said front knife means is brought into contact with the stack of paper to produce the desired trimming of the front edge thereof, said second drive means causing said second support means to move simultaneously and in synchronism with the movement of said first support means, said second drive means causing said second support means to move said front knife means into contact with the stack of paper subsequent to said side knife means trimming said side edge of the stack of papers as said first support means begins to move in said second direction whereby said trimming produced by said front and said side knife means is performed with a small phase offset.