Abstract: Lifts or sets of precise count are withdrawn from a stack of sheets. A reciprocating vacuum head serially pulls away sheet corners from the stack. Each sheet is stripped from the head and held by the backside of the head at a holding zone axially spaced apart from the stack until the desired quantity in the set is accumulated. A wedge then interposes in the space between the set of restrained corners and the rest of the stack, to bend the upper half of the sheet set away from the stack while the rest of the set remains in contact with the stack. Then nip rollers engage the bent away parts as a set and draw away the whole of the set transversely.

Abstract: A mechanical buffer for imparting a substantial delay to paper items, such as envelopes which are being individually and sequentially conveyed in a high-speed paper transport system, maintains physical separation between the conveyed items and does not require termination of item movement or item encoding. The buffer employs a directional translation of item motion, i.e., envelope motion in the length-wise direction is changed to motion in the direction of thickness, to achieve a velocity-distance compression. The buffer apparatus includes a continuous loop of item carriers which are individually positioned to have incoming items sequentially and individually inserted therein, the carriers imposing a retarding frictional force proportional to item thickness and mass to arrest item motion in the longitudinal direction as the direction of item motion undergoes the translation.