Abstract: A mechanism for depositing sheet material including a continuous belt extending between a pair of deflection rollers maintained in taut engagement thereabout, with one of the rollers being reciprocally movable relative to the other for expanding and contracting the length of the support surface in order to transport and deposit sheet material held on the support surface. A clamping mechanism operates to hold the belt stationary relative to the other of the deflection rollers when the one deflection roller is moved to contract the length of the support surface.