Compact, single fold plate, bi-roll folder, with z-fold capability

A device for forming one or more folds in a sheet, comprising:

• receiving means for receiving a sheet to be folded;
• a pair of old producing rollers for placing a fold in the sheet while withdrawing the sheet from said receiving means;
• and
• recirculating means for recirculating the once-folded sheet back into said receiving means so that said pair of fold producing rollers can place a further fold in the sheet, wherein said recirculating means is a recirculation passage extending around a portion of a circumference of one of said fold producing rollers, and at least one follower roller extending into said passage and contacting said one fold producing roller so that a sheet is conveyed around said passage by rotation of said one fold producing roller.

A sheet folding apparatus for placing at least two folds in a sheet, comprising:

• an inlet for receiving a sheet material from outside of the sheet folding apparatus;
• an outlet for discharging the sheet material to outside of the sheet folding apparatus;
• a single fold position controlling chamber having first and second ends and including at least one fold gate spaced from said first end for blocking the passage of a sheet through said fold position controlling chamber;
• a first passage extending between said inlet and the first end of said fold position controlling chamber;
• first and second fold producing rollers contacting each other at peripheral surfaces thereof and located adjacent tot he first end of said fold position controlling chamber for withdrawing a sheet from said fold position controlling chamber and placing a fold therein;
• a recirculation passage extending around a periphery of one of said first and second fold producing rollers so that a sheet can be conveyed around the outer periphery thereof and inserted back into said fold position controlling chamber after being withdrawn form said fold position controlling chamber by said first and second fold producing rollers so that all folds placed in the sheet are formed by insertion of the sheet into said single fold position controlling chamber and removal of said sheet from said fold position controlling chamber by said first and second fold producing rollers;
• and
• said outlet being in communication with one of said fold position controlling chamber and said recirculation passage.

A sheet folding apparatus, comprising:

• an inlet for receiving a sheet material from outside of the sheet folding apparatus;
• an outlet for discharging the sheet material to outside of the sheet folding apparatus;
• a fold position controlling chamber having first and second ends and including at least one fold gate spaced from said first end for blocking the passage of a sheet through said fold position controlling chamber;
• a first passage extending between said inlet and the first end of said fold position controlling chamber;
• first and second fold producing rollers contacting each other at peripheral surfaces thereof and located adjacent to the first end of said fold position controlling chamber for withdrawing a sheet from said fold position controlling chamber and placing a fold therein;
• a recirculation passage extending around a periphery of one of said first and second fold producing rollers so that a sheet can be conveyed around the outer periphery thereof and inserted back into said fold position controlling chamber after being withdrawn from said fold position controlling chamber by said first and second fold producing rollers;
• said outlet being in communication with one of said fold position controlling chamber and said recirculation passage;
• and
• a control gate located adjacent to said inlet, said fold position controlling chamber and said recirculation passage for selectively directing a sheet from said inlet into said fold position controlling chamber, from said fold position controlling chamber into a nip formed between said first and second fold producing rollers, and from said recirculation passage into said fold position controlling chamber.

A device for forming at least two folds in a sheet, comprising:

• a single fold position controlling chamber for receiving a sheet to be folded;
• a single pair of fold producing rollers for placing a fold in the sheet while withdrawing the sheet from said single fold position controlling chamber;
• and
• recirculating means for recirculating the once-folded sheet back into said single fold position controlling chamber so that said single pair of fold producing rollers can place a further fold in the sheet, wherein all folds placed in the sheet are formed by insertion of the sheet into said single fold position controlling chamber and removal of said sheet from said fold position controlling chamber by said single pair of fold producing rollers.