Stacker apparatus includes a bottom support platform movable downwardly from an upper elevation for receiving and forming a stack of flat articles such as newspapers or the like. The support platform in its upper elevation first moves generally downwardly with snap acting intercept motion for intercepting the leading edge of a flat article to begin formation of a new stack. The support platform then moves downwardly with stack forming motion different from the intercept motion. An input mechanism feeding a stream of overlapped newspapers generally flatways into the stacker apparatus includes a dump gate for deflecting the stream of newspapers away from the stacker when a jam occurs.
A sensing device for sensing individual articles such as newspapers, magazines and the like in a stream of such articles flowing along a predetermined work path. The device and method utilize a rotatably mounted polygonal sensing member having an outer peripheral surface comprised of a plurality of distinct alternating sides and corners. The sensing member is disposed at a sensing station and mounted so that the leading edge of each consecutive article in the stream engages consecutive corner and side areas of the sensing member thereby causing incremental rotation thereof. An activating vane is disposed in operative engagement with the sensing member so that during such incremental rotation, the vane is moved between non-activating and activating positions. A transducer is disposed in operative association with the activating vane such that movement of the vane between the activating and non-activating position brings the vane toward and away from a close spaced relationship therewith to cause cyclical energization and de-energization thereof. The pulses obtained from the transducer may then be employed to operate attendant equipment including, for example, a counter for maintaining an accurate count of the articles passing along the work path.
A signature stream is intercepted by a bucket unlatched from the intercept position. The buckets are moved by drive chains. A spring assembly maintains tension upon the drive chains and spring loads the bucket in the "home" position, providing a detent action upon this bucket to accelerate the bucket and also provide a force for drop-out of the bucket. A bucket cam follower guides the bucket to move from a normal path to the "home" position. A microprocessor selectively halts each bucket during downward movement to reduce free fall time of signatures. A zero force cam engaged by the bucket cam follower counteracts the force otherwise applied to the chains by variable weight signatures on the bucket to maintain uniform tension on the chains. Circular cams move the free ends of the tines increasingly faster to orient the signature stack horizontally before the bucket withdraws from beneath the batch. Oscillating paddles jog the sides and corners of the signatures during stacking to form a neat batch.
An improved apparatus for rotating and discharging articles such as stacks of newspapers combines a turntable and discharge elements in a sub-assembly that rotates as a unit relative to the frame. Rotation of the turntable and motion of the discharge elements are coordinated but not made synchronous.