Accumulator having rotary drive

A sheet stacking device comprising:

• a support frame;
• a conveyor having an intake end pivotably connected to the support frame and a discharge end, the conveyor having a width and configured to carry sheets of material in a longitudinal direction of travel from an upstream location near the intake end to a downstream position near the discharge end;
• and
• an accumulator mounted at the discharge end;
• the accumulator comprising:
• a plurality of housings, each of said plurality of housings having an interior and a channel having a channel bottom, at least some of said channel bottoms including an opening;
• a plurality of elongate fingers each having an outer end, each of said plurality of elongate fingers extending through and being slidably supported by one of said channels;
• a first set of said plurality of elongate fingers comprising a first surface having a gear rack bounded by first and second planar surface portions;
• a rotatable drive shaft extending through said plurality of housings in the width direction of the conveyor, a plurality of being gears mounted on said drive shaft,
• each of said plurality of gears extending through an opening in one of the channel bottoms and having teeth engaging the rack teeth of one of the plurality of elongate fingers;
• and
• a rotary actuator operably connected to said drive shaft, said rotary actuator rotating said drive shaft in a first direction to move the outer ends of said first set of said plurality of elongate fingers away from the conveyor discharge end and in a second direction to move the outer ends of said first set of said plurality of elongate fingers toward said discharge end.

In a sheet stacking device comprising a support frame, a conveyor having an intake end pivotably connected to the support frame and a discharge end, and an accumulator mounted at the discharge end, the accumulator comprising a plurality of elongate fingers having an outer end and having rack teeth along a first side thereof, a rotatable drive shaft extending under the plurality of elongate fingers and having drive gears engaging the rack teeth of the plurality of elongate fingers and a rotary actuator operably connected to the drive shaft, a method comprising the steps of:

• operating the conveyor to transport sheets of material along the conveyor in a direction from said intake end toward said discharge end and to drop the sheets to form a primary stack adjacent the discharge end;
• raising the discharge end to maintain the discharge end at an elevation greater than a height of the primary stack;
• controlling the rotary actuator to turn the drive shaft and the gears mounted on the drive shaft to extend the outer ends of the plurality of fingers away from the discharge end of the conveyor and into the path of sheets of material exiting the discharge end of the conveyor;
• forming a secondary stack on the plurality of fingers;
• moving the primary stack away from the sheet stacking device;
• and
• controlling the rotary actuator to turn the drive shaft and gears mounted on the drive shaft to move the outer ends of the plurality of fingers toward the discharge end of the conveyor to drop the secondary stack.