Ejector for improved stack registration

Abstract

Sheet stacking apparatus examples herein include a clamp receiving at least two sheets (e.g., a set of sheets). The clamp aligns and holds the set of sheets. The sheet stacking apparatus also includes an ejector device, an elevator platform, and a registration wall. The ejector device moves the set of sheets held by the clamp in a first direction to move the set of sheets to the elevator platform. The ejector device moves the set of sheets held by the clamp in a second direction to move the set of sheets to contact either the elevator platform or a previously stacked set of sheets. The ejector device moves the set of sheets held by the clamp in a third direction, opposite the first direction, to position the set of sheets against the registration wall. The clamp then releases the set of sheets so that they remain against the registration wall.

1 . A sheet stacking apparatus comprising:
 a clamp receiving at least two sheets, said at least two sheets comprising a set of sheets, said clamp aligning and holding said set of sheets;   an ejector device connected to said clamp;   an elevator platform adjacent said ejector device;   a cam device supporting said ejector device; and   a registration wall connected to said ejector device,   said ejector device contacting and moving over said cam device,   said cam device having a shape to control movement of said ejector device as said ejector device moves over said cam device,   said ejector device moving said set of sheets held by said clamp in a first direction from a starting position to move said set of sheets to said elevator platform,   said ejector device moving said set of sheets held by said clamp in a second direction, perpendicular to said first direction, to move said set of sheets to contact one of: said elevator platform; and a previously stacked set of sheets previously moved to said elevator platform,   said ejector device moving said set of sheets held by said clamp in a third direction, opposite said first direction, to position said set of sheets against said registration wall as said set of sheets are on one of: said elevator platform; and said previously stacked set of sheets,   said clamp releasing said set of sheets to remain against said registration wall as said set of sheets are on one of: said elevator platform; and said previously stacked set of sheets, and   said ejector device moving to said starting position to receive additional sets of sheets after said clamp releases said set of sheets positioned against said registration wall.   
     
     
         2 . The sheet stacking apparatus according to  claim 1 , further comprising an actuator moving said ejector device. 
     
     
         3 . The sheet stacking apparatus according to  claim 1 , said clamp releasing said set of sheets only after said ejector device moves in said first direction, said second direction, and said third direction. 
     
     
         4 . The sheet stacking apparatus according to  claim 1 , said ejector device moving in different parallel planes when moving in said first direction and said third direction. 
     
     
         5 . The sheet stacking apparatus according to  claim 1 , said ejector device moving toward said elevator platform when moving in said second direction. 
     
     
         6 . The sheet stacking apparatus according to  claim 1 , said elevator platform comprising an actuator moving said elevator platform in said second direction as said additional sets of sheets are moved to said elevator platform by said ejector device. 
     
     
         7 . The sheet stacking apparatus according to  claim 1 , said at least two sheets comprising sheets previously processed by a processing apparatus. 
     
     
         8 . A sheet stacking apparatus comprising:
 a clamp receiving at least two sheets, said at least two sheets comprising a set of sheets, said clamp aligning and holding said set of sheets;   an ejector device connected to said clamp;   an elevator platform adjacent said ejector device;   a cam device supporting said ejector device; and   a registration wall connected to said cam device,   said ejector device contacting and moving over said cam device,   said cam device having a shape to control movement of said ejector device as said ejector device moves over said cam device,   said ejector device moving said set of sheets held by said clamp in a first direction from a starting position as controlled by said cam device to move said set of sheets to said elevator platform,   said ejector device moving said set of sheets held by said clamp in a second direction, perpendicular to said first direction, as controlled by said cam device to move said set of sheets to contact one of: said elevator platform; and a previously stacked set of sheets previously moved to said elevator platform,   said ejector device moving said set of sheets held by said clamp in a third direction, opposite said first direction, as controlled by said cam device to position said set of sheets against said registration wall as said set of sheets are on one of: said elevator platform; and said previously stacked set of sheets,   said clamp releasing said set of sheets to remain against said registration wall as said set of sheets are on one of: said elevator platform; and said previously stacked set of sheets, and   said ejector device moving to said starting position to receive additional sets of sheets after said clamp releases said set of sheets positioned against said registration wall.   
     
     
         9 . The sheet stacking apparatus according to  claim 8 , further comprising an actuator moving said ejector device over said cam device. 
     
     
         10 . The sheet stacking apparatus according to  claim 8 , said clamp releasing said set of sheets only after said ejector device moves in said first direction, said second direction, and said third direction. 
     
     
         11 . The sheet stacking apparatus according to  claim 8 , said ejector device moving in different parallel planes when moving in said first direction and said third direction. 
     
     
         12 . The sheet stacking apparatus according to  claim 8 , said ejector device moving toward said elevator platform when moving in said second direction. 
     
     
         13 . The sheet stacking apparatus according to  claim 8 , said elevator platform comprising an actuator moving said elevator platform in said second direction as said additional sets of sheets are moved to said elevator platform by said ejector device. 
     
     
         14 . The sheet stacking apparatus according to  claim 8 , said at least two sheets comprising sheets previously processed by a processing apparatus. 
     
     
         15 . A printing apparatus comprising:
 a printer printing markings on sheets;   a clamp receiving at least two of said sheets, said at least two of said sheets comprising a set of sheets, said clamp aligning and holding said set of sheets;   an ejector device connected to said clamp;   an elevator platform adjacent said ejector device;   a cam device supporting said ejector device; and   a registration wall connected to said cam device,   said ejector device contacting and moving over said cam device,   said cam device having a shape to control movement of said ejector device as said ejector device moves over said cam device,   said ejector device moving said set of sheets held by said clamp in a first direction from a starting position as controlled by said cam device to move said set of sheets to said elevator platform,   said ejector device moving said set of sheets held by said clamp in a second direction, perpendicular to said first direction, as controlled by said cam device to move said set of sheets to contact one of: said elevator platform; and a previously stacked set of sheets previously moved to said elevator platform,   said ejector device moving said set of sheets held by said clamp in a third direction, opposite said first direction, as controlled by said cam device to position said set of sheets against said registration wall as said set of sheets are on one of: said elevator platform; and said previously stacked set of sheets,   said clamp releasing said set of sheets to remain against said registration wall as said set of sheets are on one of: said elevator platform; and said previously stacked set of sheets, and   said ejector device moving to said starting position to receive additional sets of sheets after said clamp releases said set of sheets positioned against said registration wall.   
     
     
         16 . The printing apparatus according to  claim 15 , further comprising an actuator moving said ejector device over said cam device. 
     
     
         17 . The printing apparatus according to  claim 15 , said clamp releasing said set of sheets only after said ejector device moves in said first direction, said second direction, and said third direction. 
     
     
         18 . The printing apparatus according to  claim 15 , said ejector device moving in different parallel planes when moving in said first direction and said third direction. 
     
     
         19 . The printing apparatus according to  claim 15 , said ejector device moving toward said elevator platform when moving in said second direction. 
     
     
         20 . The printing apparatus according to  claim 15 , said elevator platform comprising an actuator moving said elevator platform in said second direction as said additional sets of sheets are moved to said elevator platform by said ejector device.