Vacuum sheet stripping apparatus

Claim 2

Apparatus for removing a sheet of final support material from the surface of a moving image retaining member, including a stationary housing being arranged to substantially enclose, in air-tight relationship therewith, a rotatably mounted hollow cylinder having a line of longitudinally aligned vacuum ports therein, said housing having an elongated opening positioned adjacent the image retaining member, means to rotate said cylinder through an endless path of travel whereby the longitudinally aligned pick-up ports pass sequentially through the air-tight enclosed housing and then through the opening therein in close, non-contiguOus, relation with a sheet of material supported on the image retaining member, means to coordinate the movement of the cylinder with the movement of the image retaining member so that the longitudinally aligned vacuum ports are brought into the housing opening over the leading edge of a support sheet transported on the image retaining member, and vacuum means operatively associated with said cylinder to draw a flow of air through said ports when said ports are positioned in said housing opening to move a sufficient amount of air over the leading edge of said support sheet to raise the leading edge of the support sheet from the image retaining member into holding contact against said vacuum ports.

Claim 3

The apparatus of claim 13 wherein said cylinder has at least one other secondary opening therein positioned behind said longitudinally aligned vacuum ports in relation to the direction of cylinder movement, said second openings being arranged to engage the trailing portion of said sheet, behind the leading edge thereof, in vacuum holding contact with said cylinder as the leading edge portion of said sheet is carried forward by said cylinder.

Claim 4

The apparatus of claim 14 further including stripping means positioned between said stationary housing and said moving cylinder which is arranged to move between the surface of said cylinder and the support sheet held in contact therewith so as to redirect said sheet away from said cylinder.

Claim 5

The apparatus of claim 15 wherein one wall of said stationary housing includes an extended surface adapted to co-act with said stripping means to redirect the support sheet along a predetermined path of travel.

Claim 6

Apparatus for removing a sheet of final support material from the surface of a moving image retaining member including a rotatable hollow cylinder having a series of ports therein, vacuum drawing means operatively associated with the rotatable hollow cylinder for developinga negative pressure at said ports, means to rotate said cylinder whereby the ports are transported sequentially through a series of stations including a first station having means to seal said ports whereby a maximum negative pressure is developed at said ports, a second pick up station in which said ports are brought into close non-contiguous moving relation with the leading edge of the sheet of support material on the surface of the image retaining member whereby a flow of air is caused to move over the back of the sheet as the air is drawn through said ports to lift the leading edge of said sheet into holding contact against said cylinder, and a third sheet stripping station comprising an enclosed vacuum chamber through which said ports are passed, said chamber having one stationary wall cooperating with the rotating cylinder to strip the sheet from the cylinder and guide the sheet along a predetermined path of travel, said wall further having an opening for placing the sheet in fluid flow communication with the vacuum chamber whereby the sheet is held in sliding contact with the wall when said vacuum ports are positioned within the chamber.

Claim 7

Apparatus for removing a sheet of final support material from the surface of a moving image retaining member including a rotatable hollow cylinder having a series of ports therein, vacuum drawing means operatively associated with the rotatable hollow cylinder for developinga negative pressure at said ports, means to rotate said cylinder whereby the ports are transported sequentially through a series of stations including a first station having means to seal said ports whereby a maximum negative pressure is developed at said ports, a second pick up station in which said ports are brought into close non-contiguous moving relation with the leading edge of the sheet of support material on the surface of the image retaining member whereby a flow of air is caused to move over the back of the sheet as the air is drawn through said ports to lift the leading edge of said sheet into holding contact against said cylinder, and a third sheet stripping station comprising an enclosed vacuum chamber through which said ports are passed, said chamber having one stationary wall cooperating with the rotating cylinder to strip the sheet from the cylinder and guide the sheet along a predetermined path of travel, said wall further having an opening for placing the sheet in fluid flow communication with the vacuum chamber whereby the sheet is held in sliding contact with the wall when said vacuum ports are positioned within the chamber.

Claim 8

The apparatus of claim 10 wherein the peripheral speed of said cylinder is substantially equal to the speed of movement of the image retaining member.

Claim 9

The apparatus of claim 11 having further sheet guide means arranged to cooperate with said cylinder to redirect the stripped portion of said sheet along a predetermined path of travel.