Sheet transfer and stacking apparatus

Apparatus for transferring sheet material to a stacking station comprising:

• vertically reciprocative but horizontally stationary infeed conveyor case means,
• vertically stationary but horizontally reciprocative transfer arm means positionable between conveyor elements of said conveyor case means,
• said conveyor case means being movable vertically between a raised position for receiving sheet material and a lowered position for depositing said sheet material on said transfer arm means,
• said transfer arm means being shiftable horizontally between a retracted position between said conveyor elements and an extended position at said sheet-stacking station,
• said transfer arm means having sheet material support surfaces at a level below sheet material support surfaces of said conveyor elements when said conveyor case means is in its raised position, but above said support surfaces of said conveyor elements when said conveyor case means is in its lowered position,
• stacking means for stacking sheet material at said stacking station, said stacking means including horizontally stationary but vertically downwardly indexing stacking arm means at said stacking station,
• said stacking arm means extending parallel to but being laterally offset from said transfer arm means,
• said stacking arm means being indexable vertically between an upper limit position at a level no higher than that of said transfer arm means and a lower limit position substantially below the level of said transfer arm means for unloading a stack of sheet material therefrom,
• said stacking arm means being cantilevered toward said conveyor case means from a stacking arm support frame spaced on the opposite side of said stacking station from said conveyor case means,
• sheet accumulator means comprising horizontally reciprocative and vertically downwardly indexable accumulator arm means carried by said stacking arm support frame, said accumulator arm means being movable horizontally between a retracted inactive position offset from said stacking station and an extended active position at said stacking station for receiving sheet material from said transfer arm means, said accumulator arm means being indexable downwardly from a raised position at a level no higher than said transfer arm means to a lowered position substantially below the level of said transfer arm means but above said lowered position of said stacking arm means, and
• wherein said support frame includes a pair of transversely spaced-apart upright support columns, a first stacking arm carriage means movable vertically along said support columns supporting said stacking arm means, and a second accumulator arm carriage means movable vertically along said columns above said first carriage means and supporting said accumulator arm means.

Apparatus for transferring sheet material to a stacking station comprising:

• vertically reciprocative but horizontally stationary infeed conveyor case means,
• vertically stationary but horizontally reciprocative transfer arm means positionable between conveyor elements of said conveyor case means,
• said conveyor case means being movable vertically between a raised position for receiving sheet material and a lowered position for depositing said sheet material on said transfer arm means,
• said transfer arm means being shiftable horizontally between a retracted position between said conveyor elements and an extended position at said sheet-stacking station,
• said transfer arm means having sheet material support surfaces at a level below sheet material support surfaces of said conveyor elements when said conveyor case means is in its raised position, but above said support surfaces of said conveyor elements when said conveyor case means is in its lowered position,
• stacking means for stacking sheet material at said stacking station, said stacking means including horizontally stationary but vertically downwardly indexing stacking arm means at said stacking station,
• said stacking arm means extending parallel to but being laterally offset from said transfer arm means,
• said stacking arm means being indexable vertically between an upper limit position at a level no higher than that of said transfer arm means and a lower limit position substantially below the level of said transfer arm means for unloading a stack of sheet material therefrom,
• said stacking arm means being cantilevered toward said conveyor case means from a stacking arm support frame spaced on the opposite side of said stacking station from said conveyor case means,
• sheet accumulator means comprising horizontally reciprocative and vertically downwardly indexable accumulator arm means carried by said stacking arm support frame, said accumulator arm means being movable horizontally between a retracted inactive position offset from said stacking station and an extended active position at said stacking station for receiving sheet material from said transfer arm means, said accumulator arm means being indexable downwardly from a raised position at a level no higher than said transfer arm means to a lowered position substantially below the level of said transfer arm means but above said lowered position of said stacking arm means, and
• wherein said accumulator arm means comprises multiple parallel accumulator arms and said stacking arm means comprises multiple parallel stacking arms extending parallel to said accumulator arms, said accumulator arms being positioned when extended in vertical alignment with said stacking arms, and
• wherein said accumulator arms are nestable within said stacking arms, said accumulator arms having a sheet material support surface positioned at a level below a corresponding sheet material support surface of said stacking arms when said accumulator arms are nested within stacking arms, and
• wherein each said stacking arm is of generally U-shaped cross section, said arm opening upwardly for receiving an accumulator arm in nested relationship therewithin.

In an apparatus for transferring sheet material to a stacking station and stacking said material, a sheet-stacking apparatus comprising:

• an upright support frame including a pair of transversely spaced-apart upright support columns,
• carriage means vertically movable on said columns and including a carriage beam extending horizontally between said columns,
• multiple parallel stacking arms cantilevered horizontally from said carriage beam in transversely spaced relationship,
• and means for lowering and raising said carriage means on said support frame including indexing means for indexing said carriage means downwardly upon each receipt of sheet material on said stacking arms, and
• accumulator means carried by said support frame, said accumulator means comprising a second carriage means movable vertically along said columns above said first-mentioned carriage means, said second carriage means including a second carriage beam extending between said columns above said first-mentioned beam, and multiple parallel accumulator arms extending horizontally from said second beam parallel to said stacking arms, said accumulator arms being mounted on said second beam for horizontal reciprocation between a retracted position generally behind said stacking arms and an extended position overlying said stacking arms.