Apparatus for feeding lifts of limp sheets

Apparatus for feeding lifts of identical limp flexible sheets from a stack of such sheets, said apparatus comprising

• sheet magazine means supporting a stack of limp flexible sheets and having a bottom with a slot formed therethrough, said bottom having spaced opposite first and second ends, and an end feed gateway at the first of said ends;
• mechanical sheet separating and segregating means for splitting off and segregating each successive bottom-most lift of said stack of said sheets from the remainder of said stack and urging same through the end feed gateway, said sheet separating and segregating means comprising stabber-separator means movable toward said first end to support said stack at a selected distance above said bottom of said sheet magazine means and pin extender means movable toward said first end into said stack at a selected distance above said stabber-separator means for segregating a bottom-most lift of said stack by being interposed in said stack above said lift, said stabber-separator means being movable toward said second end to a position spaced from said stack thereby permitting said lift to drop to said bottom of said sheet magazine means and movable back toward said first end directly under said pin extender means;
• lift extracting means comprising a pusher device movably mounted on said bottom of said sheet magazine means and movable toward said first end to push the lift under said stabber-separator means through said end feed gateway, said pin extender means then being movable toward said second end to a position spaced from said stack whereby said stack again rests on said stabber-separator means;
• pin extender moving means coupled to said pin extender means for selectively moving said pin extender means toward the first end of the bottom of said sheet magazine means into said stack at said selected distance above said stabber-separator means and toward said second end of said bottom to a position spaced from said stack;
• stabber-separator moving means coupled to said stabber-separator means for selectively moving said stabber-separator means toward said first end of said bottom of said sheet magazine means to support said stack at a selected distance above said bottom and toward said second end of said bottom to a position spaced from said stack;
• pusher moving means coupled to said pusher device for selectively moving said pusher device toward said first end of said bottom of said sheet magazine means to push the lift under said stabber-separator means through said end feed gateway and toward said second end of said bottom to a position spaced from said lift;
• a trap door movably mounted in operative proximity with said end feed gateway;
• trap door moving means coupled to said trap door for selectively moving said trap door toward said bottom of said sheet magazine means to block said end feed gateway and away from said bottom to free said end feed gateway, each of said pin extender moving means, said stabber-separator moving means, said pusher moving means and said trap door moving means including an air piston unit having a piston rod coupled to said pin extender means, said stabber-separator means, said pusher means and said trap door, respectively;
• and
• control means coupled to said pin extender moving means, said stabber-separator moving means, said pusher moving means and said trap door moving means for controlling the operation of said pin extender moving means, said stabber-separator moving means, said pusher moving means and said trap door moving means for moving said pin extender means, said stabber-separator means, said pusher device and said trap door in predetermined directions at predetermined times in accordance with a predetermined cyclic program, said control means comprising a source of compressed air, a plurality of air ducts extending from said source of compressed air to said pin extender air piston unit, said stabber-separator air piston unit, said pusher air piston unit and said trap door air piston unit, a plurality of valves each connected in a corresponding one of said air ducts for selectively permitting and preventing the flow of air therethrough, a plurality of cams, each in operative proximity with a corresponding one of said valves, and motive means coupled to said cams for rotating said cams to operate said valves in accordance with said program.

Apparatus for feeding lifts of identical limp flexible sheets from a stack of such sheets, said apparatus comprising

• sheet magazine means supporting a stack of limp flexible sheets and having a bottom with a slot formed therethrough, said bottom having spaced opposite first and second ends, and an end feed gateway at the first of said ends;
• mechanical sheet separating and segregating means for splitting off and segregating each successive bottom-most lift of said stack of said sheets from the remainder of said stack and urging same through the end feed gateway, said sheet separating and segregating means comprising stabber-separator means movable toward said first end to support said stack at a selected distance above said bottom of said sheet magazine means and pin extender means movable toward said first end into said stack at a selected distance above said stabber-separator means for segregating a bottom-most lift of said stack by being interposed in said stack above said lift, said stabber-separator means being movable toward said second end to a position spaced from said stack thereby permitting said lift to drop to said bottom of said sheet magazine means and movable back toward said first end directly under said pin extender means, said stabber-separator means comprising an elongated plate having a top surface, a bottom surface, a pair of sides, a back and a front tapered from said sides and from said top and bottom surfaces, said stabber-separator means being mounted with said top and bottom surfaces substantially parallel to said bottom of said sheet magazine means and said front pointed toward said first end of said bottom, said plate of said stabber-separator means further comprising a protrusion extending from said top surface thereof from said front to said back equidistantly from said sides and having a protruding top surface spaced from and substantially parallel to said upper surface of said plate;
• lift extracting means comprising a pusher device movably mounted on said bottom of said sheet magazine means and movable toward said first end to push the lift under said stabber-separator means through said end feed gateway, said pin extender means then being movable toward said second end to a position spaced from said stack whereby said stack again rests on said stabber-separator means;
• and
• a trap door movably mounted in operative proximity with said end feed gateway and positionable to selectively block and clear said gateway.