Patent ID: 6860481

Claim:
A sheet stacking device for stacking sheets, comprised of: at least one gripper device movable along a track operable to releasably grip a leading edge of a sheet material in a direction of motion; gripper drive means operable to move said gripper device from a first location to a second location; two spaced-apart support devices supporting said sheet as said sheet moves from said first location to said second location, said support devices having a supporting position, wherein said support device supports said sheet and a non-supporting position wherein support for said sheet is removed; a stacking platform below said second location; and control means for controlling said gripper device, said gripper drive means and said support device, wherein said control means causes 1) said gripper device to grip a leading edge of said sheet at said first location, 2) said drive means to move said gripper device along said track from said first location to said second location, 3) said gripper device to release said leading edge of said sheet at said second location, and 4) said support device to move from said supporting position to said non-supporting position, dropping said sheet onto said stacking platform.