Sheet sorting apparatus

Abstract

The vertical stack of trays in a movable tray sorter for sheets of paper exiting a . .copies.!. .Iadd.copier .Iaddend.is moved in a manner to enlarge the spacing between consecutive pairs of the trays to accept consecutive sheets of paper by moving the trays along a pair of helical coils, each of which has a turn of relatively coarse pitch. The turns of relatively coarse pitch are located at the copier paper chute and causes an increased separation of adjacent trays only at that position as the coils are turned. .Iadd.The coils support the trays approximately midway between the ends of the trays in a sheet feeding direction and the sorter has vertically extended guides at opposite sides of the trays adjacent one end in which side portions of said trays slide to maintain the trays substantially parallel. .Iaddend.

What is claimed is: 
     
       1. A sheet sorting apparatus of the shifting tray type for receiving paper sheets, comprising. .;.!..Iadd.: .Iaddend. a pair of helical coils, each coil of said pair of helical coils being predominantly . .would.!. .Iadd.wound .Iaddend.with a plurality of turns of a first pitch, and containing at least one turn of a second pitch, the second pitch being coarser than the first pitch, each coil having a longitudinal axis;   means for rotational support, the support means holding the coils in positions wherein said longitudinal axes of the coils are approximately parallel to each other;   means for rotational drive, the drive means rotating each coil about said longitudinal axis, both coils rotating in the same sense and at the same speed of rotation;   a plurality of trays arranged in a stack, each said tray being separated from an adjacent said tray by a space, each tray having a leading edge for receiving the sheets, two side edges on either side of the leading edge, the side edges defining the sides of the stack, and a surface for supporting the sheets, one said coil being positioned adjacent to each of said sides of the stack;   one of said coils being positioned at about the center of each of said side edges; and   a plurality of tray lift blocks, each tray having a pair of the tray lift blocks . .for.!. .Iadd.providing .Iaddend.attachment . .of.!. .Iadd.means connecting .Iaddend.the tray to coils, each tray lift block having a means for tray engagement and a helical shaped guideway therethrough, the guideway providing clearance for sliding engagement of the tray lift block with the coil so that as the coil rotates the attachment means moves along the coil in accordance with the direction of rotation of the coil;   said apparatus including a pair of vertical guides, each of said leading edges of said trays including extensions for engaging said guides;   whereby the stack of trays move along the pair of coils as the coils rotate, the space between each pair of adjacent trays being approximately equal for adjacent trays moving on the coil turns of the first pitch, the space between each pair of adjacent trays growing to a larger spacing as each tray moves into the coil turns of the second pitch, the larger spacing facilitating the ingress of the sheet of paper, so that each tray in turn may receive a paper sheet.   
     
     
       2. The apparatus of claim 1 wherein the helical shaped guideway encompasses approximately one complete coil turn of the first pitch and a fraction of a coil turn of the second pitch. 
     
     
       3. The apparatus of claim 1 further including a center rod for mounting the coil, each end of the center rod having a traverse through hole for accepting one end of the coil, the rod being positioned coaxially through the coil, and wherein the attachment means has a clearance hole for passage of the center rod, the center rod acting to restrain the tray lift block from tilting out of planes orthogonal to the axis of the coil. 
     
     
       4. Apparatus comprising a helical coil of solid cross-section, said coil being wound predominantly with a plurality of turns of the same sense and a first pitch and containing one turn of a second pitch of the same sense as but coarser than said first pitch, said coil having a longitudinal axis and a rotary drive positioned co-axially and extending along said axis and connected to the ends of said coil, . .said.!. .Iadd.including a .Iaddend.rod . .being.!. secured to said ends of said coil and being of a length . .of.!. .Iadd.to .Iaddend.maintain said coil in a rigid configuration along said axis, and including a plurality of lift blocks shiftably disposed on said coil, each of said lift blocks having a helical path therethrough, said path being of a geometry to accept at most one turn of said coil and also having therethrough a center hole for communicating with said rod. 
     
     
       5. Apparatus as set forth in claim 4 wherein said rod engages . .a.!. .Iadd.associated .Iaddend.means for rotating said rod along said axis. 
     
     
       6. First and second apparatus as set forth in claim 5 in fixed spaced apart positions and control means for synchronizing the associated means for rotating. 
     
     
       7. . .Apparatus.!. .Iadd.First and second apparatus .Iaddend.as set forth in claim 6 including a plurality of trays and means for organizing said trays into a vertical .Iadd.stack, .Iaddend.each of said trays being connected to like numbered lift blocks associated with said coils of said first and second apparatus. 
     
     
       8. . .Apparatus.!. .Iadd.First and second apparatus .Iaddend.as set forth in claim 7 including .Iadd.rotational drive .Iaddend.means for activating said associated means for rotating said coils in a manner to move said lift blocks along respective ones of said longitudinal axes, said means for organizing being of a geometry to constrain movement of said trays vertically to consecutive horizontal positions of said stack. 
     
     
       9. . .Apparatus.!. .Iadd.First and second apparatus .Iaddend.as set forth in claim 8 . .therein.!. .Iadd.wherein .Iaddend.said one turn of a second pitch is aligned with the position of a paper feed such that the movement of said trays to successive . .horizontal.!. .Iadd.vertical .Iaddend.positions is operative to increase the spacing between the tray aligned with said position and the tray aligned with the next adjacent position. .Iadd. 
     
     
       10.  A sheet sorting apparatus of the shifting tray type for receiving paper sheets fed into the trays from a copier or printer, comprising: a pair of helical cams providing coils, each coil of said pair of helical coils being predominantly wound with a plurality of turns of a first pitch, and containing at least one turn of a second pitch, the second pitch being coarser than the first pitch, each coil having a longitudinal axis;   means for rotational support, the support means holding the coils in positions wherein said longitudinal axes of the coils are approximately parallel to each other;   means for rotational drive, the drive means rotating each coil about said longitudinal axis, both coils rotating in the same speed of rotation;   a plurality of trays arranged in a stack, each said tray being separated from an adjacent said tray by a space determined by the first and second pitch, each tray having a leading end facing upstream of the paper sheet infeed direction for receiving the sheets and a downstream end and two side edges extending between said leading end and downstream end;   one of said coils being positioned at about the center of each of said side edges;   means for moving said trays in response to operation of said means for rotary drive including follower members on the opposite side edges of each tray for engagement with the coils so that as the coils rotate the follower members cause said trays to move along the respective coils in accordance with the direction of rotation of the coil;   said apparatus including a pair of vertical guides, each of said side edges of said trays including extensions adjacent one of said ends of said trays for engaging said guides to maintain the trays parallel;   whereby the stack of trays moves along the pair of coils as the coils rotate, the space between each pair of adjacent trays being approximately equal for adjacent trays moving on the coil turns of the first pitch, the space between each pair of adjacent trays growing to a larger spacing as each tray moves into the coil turns of the second pitch, the larger spacing facilitating the ingress of the sheet of paper, so that each tray in turn may receive the sheets of paper. .Iaddend..Iadd.   
     
     
       11.  A sheet sorting apparatus as defined in claim 10 wherein said vertical guides and said extensions on said trays are located at the leading end of said trays. .Iaddend.