An ingestion assembly is provided for a singulating apparatus having a conveyor system for moving a stack of sheet material along a feed path. The ingestion assembly is spatially positioned above the conveyor belt and includes at least one singulating roller driven in a direction opposing the motion of the conveyor belt. The ingestion assembly comprises an assembly support rotationally mounting the singulating roller at a downstream end portion and pivotally mounting to the singulating apparatus at an upstream end portion. A movable guide mounts to the assembly support and is positionable relative thereto as a function of a force vector imposed on the guide by the sheet material. Additionally, the moveable guide includes a surface operative to guide the sheet material into a singulating interface which is formed between the singulating roller and the conveyor system. In operation, sheet material enters the throat of the ingestion assembly and contact is made with the moveable guide. When the force vector, imposed by the sheet material, is less than a threshold level, the guide assumes a first position operative to shingle sheet material in preparation for singulation by the singulating roller. When the force vector, is greater than the threshold level, movable guide assumes a second position operative to pivot the assembly support and increase the singulating interface. Consequently, sheet material having a larger thickness dimension may pass for separation by the singulation apparatus.