Sheet transfer apparatus
AssigneeGeorgia-Pacific Corporation
InventorRobert J. Wise
Life of this patent
Estimating the term…
Abstract
A sheet transfer apparatus (10) is disclosed. The apparatus (10) includes a first station (14), a second station (16) and a transfer mechanism (18) for transferring stiff sheets (20A,B) from the first station (14) to the second station (16). A conveyor mechanism (48) moves the sheet (20B) in a first direction (49) from the second station (16). Push-plates (32) are provided for releasing the sheet (20B) from the transfer mechanism (10) at the second station (16). A pair of longitudinally spaced bar members (50) apply downward pressure to a sheet (20B) falling downward onto the conveyor mechanism (48). Each bar member (50) is supported in an inoperative position by one of the push-plates (32).
Claims22
A sheet transfer apparatus comprising:
- a first station;
- a second station;
- means for transferring stiff sheets from said first station to said second station;
- conveyor means for moving sheets in a first direction from said second station;
- a portion of said transfer means being located adjacent said second station to hold a sheet above said conveyor means;
- release means for releasing a sheet held by said transfer means at said second station from said transfer means to allow the released sheet to float downwardly to said conveyor means whereby the released sheet can subsequently be moved by said conveyor means;
- hold-down means comprised of first and second bar members with contact surfaces for contacting the upper major surface of the released sheet during its entire downward floating motion, said first and second bar members extending in a second direction transverse to said first direction and across a major portion of the released sheet's dimension in said second direction, said first bar member being disposed adjacent a first end of the released sheet in said first direction and said second bar being disposed adjacent a second opposite end of the released sheet in said first direction.
In a sheet transfer apparatus including transfer means for transfering stiff sheets from a first station to a second station, release means for releasing a sheet held by said transfer means at said second station and for providing a downward force on the released sheet, said release means including a push plate movable between an upper position and a lower position for pressing downward on the sheet being released from the transfer means whereby the released sheet floats downward, the improvement comprising hold-down means for contacting the released sheet during its entire downward motion, said hold-down means including a bar member having a contact surface for contacting the upper major surface of the released sheet and a support member for supporting said bar member for motion between an inoperative position wherein said bar member is out of contact with the released sheet and an operative position wherein said bar member contacts the upper major surface of said released sheet, said support member including at least one arm supported by said push plate in the inoperative position of said hold-down means in the upper position of said push plate and said support member being free to move downwardly when said push plate is in the lower position.
In a sheet transfer apparatus including an endless belt vacuum transfer means for transferring stiff sheets from a first station to a second station, the transfer means including a pair of spaced parallel vacuum-applying endless belts, release means for releasing a sheet from the vacuum-applying belts to allow the released sheet to float downward at the second station, said release means including a push plate disposed adjacent each of the vacuum-applying belts, each of the push plates being moveable from an upper position out of contact with the sheet being released and a downward position into contact with the sheet held by the vacuum-applying belts to release the last-mentioned sheet from the holding force of the vacuum-applying belts to allow the released sheet to float downward, the improvement comprising:
- hold-down means for contacting the upper major surface of the released sheet during substantially its entire downward motion;
- said hold-down means including a bar member movably disposed adjacent each of said push bars, each bar member having a contact surface for contacting the upper major surface of the released sheet, each bar member being attached to a pair of spaced pivotable arms, each pair of spaced pivotable arms being connected to said apparatus for pivotable motion between an upper inoperative position wherein said bar members are out of contact with the released sheet and an operative position wherein the bar members and the pivotable arms are free to move downwardly, each pair of pivotable arms being supported in the inoperative position by one of said push plates and being released to said operative position when said push plates move downwardly to release a sheet from said vacuum-applying belts.
A sheet transfer apparatus comprising:
- a first station;
- a second station;
- vacuum transfer means for transferring stiff sheets from said first station to said second station, said vacuum transfer means including a pair of spaced parallel vacuum-applying endless belts for applying a vacuum lifting force on a sheet to be transferred;
- conveyor means for moving sheets in a first direction from said second station;
- a portion of said transfer means being disposed above said conveyor means to hold a sheet being transferred thereabove;
- release means for releasing a sheet held by said transfer means at said second station from said transfer means to allow the released sheet to float downwardly to said conveyor means, said release means including a push-plate movable upwardly and downwardly between an upper inoperative position and a lower operative position whereby said push-plate presses against a sheet held by said transfer means above said conveyor means and presses downwardly on said sheet to release said sheet from the vacuum lifting force of said vacuum-applying endless belts;
- hold-down means including first and second shafts, each of said shafts having a plurality of rollers and disposed along its length with an outer rotatable surface of each roller forming a contact surface for contacting the upper major surface of the released sheet during its entire downward floating motion, said first and second shafts extending in a second direction transverse to said first direction, said rollers being located across a major portion of the released sheet's dimension in said second direction, said first shaft being pivotably supported by a pair of pivot arms adjacent the first end of the released sheet in said first direction, and said second shaft being pivotably supported by a pair of pivot arms adjacent a second opposite end of the released sheet in said first direction;
- each pair of said spaced pivotable arms being connected to said apparatus for pivotable motion between an inoperative position wherein said rollers are out of contact with the released sheet and an operative position wherein the rollers and the pivotable arms are free to move downwardly for the rollers to contact and press down upon the released sheet, each pair of pivotable arms being supported in the inoperative position by one of said push-plates when said push-plate is in its upper position and being released to said operative position when said push-plate move downwardly to release a sheet from said vacuum applying belts;
- and
- stop means for stopping the downward pivoting motion of each pair of pivotable arms.
Dependencies are inferred from the claim text.