Stapling head for a stapling machine

A stapling head operable during a working stroke to staple piled sheets of paper using wire staples, comprising:

• a frame;
• a staple holder guided in said frame and being displaceable in a working direction essentially perpendicular to the sheets of paper;
• a staple driver guided on said staple holder and being displaceable in the working direction;
• and
• driving means for moving said staple holder and said staple driver in the working direction during a first phase of the working stroke so that said staple holder is moved onto the piled sheets, and is stopped at the piled sheets at an end of the first phase;
• for moving said staple driver further in the working direction to drive a wire staple out of said staple holder and into the piled sheets during a second phase of the working stroke;
• and for moving said staple driver and said staple holder back into their initial positions during an idle stroke, said driving means comprising:
• a cam plate rotatably mounted in said frame, and being movable in the working direction;
• a first connecting rod having one end eccentrically connected to said cam plate, and another end pivotally connected to said staple holder, and being moved by said cam plate in an eccentric direction relative to the working direction;
• a second connecting rod having one end eccentrically connected to said cam plate, and another end pivotally connected to said staple driver, and being moved by said cam plate in an eccentric direction relative to the working direction;
• and
• guide means including a guide link attached to said frame for supporting and rotationally locking said cam plate to positionally fix said staple driver relative to said staple holder during the first phase, and unlocking said cam plate during the second phase so that said staple driver and said staple holder are not positionally fixed relative to each other.