Document singulating apparatus for feeding upright documents of varying thickness

In an apparatus for singulating respective documents fed thereto, wherein each of said documents is uprightly oriented on an edge thereof and has oppositely facing upright surfaces, and wherein each successive document is slidably movable relative to a next successive document against an interdocument frictional force developed therebetween, the apparatus comprising first document feeding means including at least two first belts and first means for moving said first belts downstream relative to a path of travel in vertically spaced first belt runs, and second document feeding means, adjacent said first document feeding means, including at least one second belt and second means for moving said second belt upstream relative to said path of travel in a second belt urn, an improvement to said second document feeding means comprising:

• a. a first section including an upstream end and a downstream end, said upstream end being pivotally mounted to a frame member, said first section also including at least two outboard endless belts therearound, said first section including second means for moving said outboard belts upstream relative to a path of travel in vertically spaced second belt runs,
• b. a second section having at least two inboard endless belts therearound, said second section being pivotably mounted at one end to said first section,
• c. means for coupling movement of said outboard belts of said first section to movement of said inboard belts of said second section for driving said inboard belts of said second section upstream relative to a path of travel in vertically spaced second section belt runs,
• d. means for resiliently urging said second section belt runs into interleaving relationship with said first belt runs, and for resiliently urging the downstream end of said first section belt runs towards said first belt runs, said urging means enabling said first and second sections to laterally flexed about said coupling means in response to said documents fed thereto;
• e. said first belt runs exerting a downstream frictional force greater than an interdocument frictional force on an upright surface of each successive document for feeding thereof downstream in said path of travel, said first section and second section belt runs exerting an upstream frictional force greater than said interdocument frictional force on the oppositely facing upright surface of each next successive document for feeding thereof upstream relative to said path of travel, said second section belt runs exerting an upstream frictional force greater than said first section belt runs, and said downstream frictional force exceeding said upstream frictional force, whereby said first belt runs successively feed each successive document downstream in said path of travel against said interdocument and upstream frictional forces.