Pneumatic sheet material hold down conveyor system

摘要

A pneumatic sheet material hold-down conveyor system is described in which a frame mounts conveyor having a movable working flight. A first manifold with a support surface movably supports the working flight. Air intake openings are formed through the support surface, connected to a vacuum source for producing suction against the sheet material to draw the sheet material against the working flight. A second manifold is also provided on the frame, with a discharge surface extending along and in spaced relation to the working flight. Air discharge openings formed through the discharge surface is directed toward the working flight. A positive air pressure source is connected to the second manifold and is configured to pressurize the second manifold such that pressurized air is delivered through the air discharge openings toward the working flight and against the sheet material to push the sheet material against the working flight. A flat sheet positioned on the working flight between the first and second manifolds is thereby held against the working flight by positive air pressure on one side and negative air pressure on an opposite side. Thus secured, the sheet material may be moved by the working flight and be folded by the forming mandrel. A forming mandrel is provided on the frame and extends along the working flight to engage and progressively fold sheet material moving along the working flight.