Doctor blade drive

In a printing press having a form cylinder and a doctor blade, means for mounting the doctor blade for longitudinal oscillatory movement relative to the form cylinder, and means for generating oscillating movement of said doctor blade wherein the improvement comprises:

• said oscillating movement generating means includes a pivotably mounted rocker, means coupling the rocker to the doctor blade, means for sequentially pivoting said rocker in opposite directions to effect oscillation longitudinal movement of said doctor blade, and means for continuously displacing the pivot axis of said rocker independently of the press operation for continuously varying the points of reversal of the doctor blade oscillating movement, said means for continuously displacing the rocker pivot axis including a shaft having an eccentric section, first one way idler bearing means for supporting said rocker on said eccentric shaft portion for rotation about an eccentric axis thereof, means including second one way idler bearing means for supporting said shaft for rotational movement about a pivot axis of said shaft, said first bearing means being operable to permit rotational movement of said rocker relative to said eccentric shaft portion in one direction while said second bearing means blocks rotational movement of said shaft in such direction about said pivot axis, and said second bearing means being operable to permit rotational movement of said shaft about said pivot axis in an opposite direction while said first bearing means blocks rotational movement of said rocker relative to said eccentric shaft portion in such direction.