Abstract: A high speed sheet stacker includes a plurality of vacuum transport sub-assemblies interdigitated with an adjacent sub-assembly and provided with a spatial pitch that is less than or equal to a predetermined shingle distance. The collective vacuum transport assembly can thus acquire shingled sheets and transport the shingled sheets as a set, with each sheet being offset by at least one shingle distance. As a result, speed and acceleration requirements for the vacuum transport and the sheets being transported are greatly reduced compared to conventional vacuum transports that essentially transport sheets singularly. A shingled transport zone may be provided upstream of the vacuum transport system to accommodate sheets of varying size. In various embodiments, three to five vacuum transport sub-assemblies are provided to transport three to five sheets as a set.

Abstract: The present disclosure provides a printing device comprising a sheet buffer including a paper path having a plurality of nip pairs for selectively receiving and releasing a plurality of printer sheets. The plurality of nip pairs include a fixed load nip pair, a fixed unload nip pair, and at least another intermediate fixed nip pair therebetween. In a first operation each subsequent sheet of the plurality of sheets is shingled over a previous sheet wherein the plurality of sheets can be stopped in the intermediate nip pair or pairs. Individual sheets of the plurality of sheets can be advanced to the unload nip pair sequentially in a second operation whereupon the individual sheets are successively unloaded as needed in a first in first out order.

Abstract: A stalled roll registration system and method includes a mechanism that allows for pivoting deskew action in a pre-registration nip in the form of a segmented pre-registration drive roll assembly mounted on a releasable low friction lateral translation carriage. Outer pre-registration idler nips are provided that open to allow a sheet to pivot and close for transport the sheet. The pre-registration idlers are engaged and the drive roll assembly remains locked in the lateral position for initial paper transport up to the stalled registration roll. After the sheet arrives at the stalled registration roll and starts to form a buckle for deskew, the outer pre-registration idlers and carriage are released. The body of the sheet is then free to pivot about the center drive nip and translate in the lateral direction to self align itself with the registration roll.

Abstract: A gateless rocker inverter for reversing the lead and trail edges of a sheet includes two idler roll and drive roll nip pairs with the drive rolls continuously rotating in opposite directions. The idler rolls are attached to two ends of a coupler of a four-bar linkage which opens and closes the nips in sequence, first to drive the sheet forward and subsequently to drive the sheet in a reverse direction out of the inverter for duplexing purposes.

Abstract: A full productivity, tri-roll inverter for reversing the lead and trail edges of a sheet includes an input nip and an output nip positioned to feed sheets at a machine's process speed into and out of a chute and a reversing roll nip positioned in a predetermined position along the chute closely adjacent to but downstream of the input and output nips and adapted to open and allow a sheet to be driven into the chute by the input nip and closed to drive a sheet into the output nip. After a first sheet is captured by the output nip, the reversing roll nip is opened and a second sheet is driven into the chute by the input nip while the first sheet is simultaneously being pulled out of the chute by the output nip.

Abstract: A non-contact, transmissive energy sensor is utilized for determining the thickness of paper sheets in a feed path. The sensor includes an energy emitting source and an energy detector, the output of the energy detecting source being proportional to the amount of energy received by the energy detector. The signal output level of the detector is utilized in a model to determine the basis weight of paper in the detecting zone of the detector. Heuristic sampling techniques can be utilized to reduce or eliminate the effects of images printed on the paper and flutter of the paper as it moves. An automatic calibration routine utilizing boundary coefficients is used to calibrate the paper basis weight detection system. The paper basis weight determination is utilized to control subsequent operations to which the paper sheet is subjected in order to optimize image quality and sheet handling, and to control finishing operations.