Paper feed apparatus for sheet-fed press

A paper feed apparatus for a sheet-fed press, comprising:

• a paper stack unit for stacking paper sheets on a paper stack plate thereof;
• a suction port member for drawing a leading end portion of a paper sheet stacked on said paper stack unit, said suction port member being movable between a suction position at which the leading edge portion of the paper sheet is engaged on said stack, an upper position above the suction position and a retreat position before the suction position and after the upper position in a paper feeding direction of the paper sheet, the traveling path of the suction port member from the retreat position to the suction position disposed at the position lower than that from the upper position to the retreat position, and at a portion lower than the sheet transport path of the paper convey means;
• driving means for moving said suction port member cyclically from the retreat position to the suction position, and then to the upper position in that order;
• and
• paper convey means, disposed within a forward path of said suction port member, for drawing the paper sheet released by said suction port member and feeding the paper sheet in the paper feeding direction, a convey speed of said paper convey means being substantially the same as a moving speed of said suction port member from the upper position to the retreat position,
• wherein said suction port member draws the paper sheet at the suction position subsequently releases the paper sheet drawn at the initial period of a movement thereof from the upper position to the retreat position to transfer the paper sheet released to said paper convey means, and subsequently retreats downward from a paper convey path of the paper sheet in a last period of the movement thereof from the upper position to the retreat position.