Mechanism and method for accumulating and folding sheets

A mechanism for accumulating and folding a plurality of sheets, comprising:

• a) a pair of in take rollers;
• b) a guide for guiding sheets into the nip of said intake rollers
• c) an urge roller for urging said sheets along said guide into said nip to form an accumulation having the leading edges of said sheets aligned while said intake rollers are stopped or operating in a reverse direction.
• d) a buckle chute aligned with said intake rollers to stop the leading edges of said accumulation after they have travelled a predetermined distance, whereby further driving by said intake rollers will cause said accumulation to buckle around a predetermined transverse line;
• and,
• e) a pair of fold rollers aligned to capture said accumulation as it buckles and fold said accumulation on said transverse line.

A mechanism for folding an accumulation of sheets, comprising:

• a) a pair of intake rollers for capturing said accumulation;
• b) a buckle chute for receiving said accumulation and causing said accumulation to buckle around a predetermined transverse line;
• c) a pair of fold rollers for capturing said accumulation as it buckles and folding said accumulation on said transverse line;
• d) motor means responsive to the passage of said accumulation through said apparatus for operating said apparatus at first speed until approximately the time when said fold rollers capture said accumulation and then operating said apparatus with increased torque.

A method for folding sheets comprising the steps of:

• a) providing a folding apparatus, said folding apparatus including a pair of intake rollers;
• b) forming an accumulation of sheets having the leading edges of said sheets aligned in the nip of said intake rollers;
• and
• c) then operating said folding apparatus to fold said accumulation.

An mechanism for accumulating and folding a plurality of sheets, comprising:

• a) means for folding an accumulation of sheets, said folding means including means for activating said apparatus and a pair of intake rollers;
• b) means for urging a plurality of sheets into the nip of said pair of intake rollers while said intake rollers are inoperative to capture said sheets, whereby said accumulation is formed in said nip;
• wherein,
• c) said activating means is responsive to formation of said accumulation to activate said apparatus to fold said accumulation;
• and wherein,
• d) said activating means activates said intake rollers in a first direction for a predetermined period as said accumulation is forming and then in the opposite direction to capture said accumulation.

A mechanism for accumulating and folding a plurality of sheets, comprising:

• a) a pair of intake rollers;
• b) a guide for guiding sheets into the nip of said intake rollers;
• c) an urge roller for urging said sheets along said guide into said nip to form an accumulation while said intake rollers are stopped or operating in a reverse direction;
• d) a buckle chute aligned with said intake rollers to stop the leading edges of said accumulation after they have travelled a predetermined distance, whereby further driving by said intake rollers will cause said accumulation to buckle around a predetermined transverse line;
• e) a pair of fold rollers aligned to capture said accumulation as it buckles and fold said accumulation on said transverse line;
• f) sensors for detecting the presence of said sheets on said guide;
• g) a motor for activating said apparatus;
• and,
• h) a controller responsive to said sensors for controlling said motor to so that said intake rollers are inoperative to capture said sheets until said accumulation is formed and then to activate said apparatus to capture and fold said accumulation.

A mechanism for accumulating and folding a plurality of sheets, comprising:

• a) a pair of intake rollers;
• b) a guide for guiding sheets into the nip of said intake rollers;
• c) an urge roller for urging said sheets along said guide into said nip to form an accumulation while said intake rollers are stopped on operating in a reverse direction.
• d) a buckle chute aligned with said intake rollers to stop the leading edges of said accumulation after they have travelled a predetermined distance, whereby further urging by said intake rollers will cause said accumulation to buckle around a predetermined transverse line;
• e) a pair of fold rollers aligned to capture said accumulation as it buckles and fold said accumulation on said transverse line;
• and,
• f) means for increasing the columnar stiffness of said sheets, whereby buckling of said sheets as said accumulation is formed is avoided.

A method for folding sheets comprising the steps of:

• a) providing a folding apparatus, said folding apparatus including a pair of intake rollers;
• b) forming an accumulation of sheets in the nip of said intake rollers while stiffening said sheets to avoid buckling of said sheets as said accumulation is formed;
• and
• c) then operating said folding apparatus to fold said accumulation.