Device for aligning signatures fed in shingled relation

In a device for aligning signatures fed in shingled relation prior to stacking them, which includes a frame, a horizontal delivery belt trained about inlet and outlet pulleys supported on the frame to form a signature supporting run carrying a stream of signatures in shingled relation, driving means for driving the belt for transportation of the signatures, a pair of upstanding guide belts straddling the delivery belt and presenting opposed faces thereto, each guide belt having an upstream sheave and a downstream sheave mounted in the frame on vertical shafts and coupled to the driving means for driving of the guide belts in unison with one another and at the same speed as the delivery belt, the guide belts being convergently arranged with the downstream sheaves thereof being spaced to define between them a discharge opening having the desired width of the stream in the aligned state, the upstream sheaves being spread apart with respect to the downstream sheaves by substantially equal amounts of offset to define a funnel-like entryway adequate to accommodate entry of the stream in non-aligned condition with individual signatures irregularly displaced from the stream, and pulsating shifter means behind the presented faces of the belts and having a drive connection coupled to the driving means for repetitively moving said faces from a substantially planar reference position to a thrown position in which the belts are angularly bowed mutually inwardly toward the stream thereby dividing each face into a convergent upstream portion and a downstream portion, the throw of the shifter means being such that the downstream portions in their thrown positions are substantially parallel to the direction of movement of the stream for jogging the straight edges of the stream from opposite sides to insure a condition of precise alignment as the stream moves through the discharge opening.