Abstract: A replacement drive roll having an integral bearing for easy replacement and universal usage in a printing machine. The roll member has a bearing having a nonround outer race for retention in a frame member and a nonround inner race for engagement with a driveshaft on one end. The opposite end has a locking member for preventing axial movement along the shaft. The roll assembly has elastomer bands stretched around the outer circumference to form the drive surface of the roll. The roll unit is easily replaced and can be used in numerous locations thereby reducing parts inventory requirements.

Abstract: A floating feedhead having a variable sheetpath for an electrophotographic printing machine. A feeder for feeding sheets from the top of a stack to a processor for a printing machine is disclosed. The feedhead is of a standard retard feed type having either a nudger roll/feed roll or a feed belt in combination with a retard member to separate sheets. The feedhead is connected to the sheet delivery area of the machine by a variable length, variable speed sheetpath. The sheetpath has a drive member such as a drive nip in cooperation with the feedhead. When the sheetpath is at its longest the feedhead and variable drive member operate at a higher speed to deliver the sheets to the sheet intake area at a predetermined time interval. As sheets are fed and the sheetpath becomes shorter, the variable drive and feedhead slow to maintain proper sheet timing. The sheetpath may be of a telescopic baffle configuration or could alternatively be a variable speed vertical transport arrangement.

Abstract: A duplex path loop having a acceleration nip cooperating with a belt transport and retime nip to allow duplexing of sheets while minimizing skipped pitches on the photoreceptor. As each sheet to be duplex printed is removed from the process path after first side imaging it is accelerated to create a gap between it and subsequent sheets. The sheet is then stalled or slowed in a retime nip, while subsequent sheets to be duplexed are simultaneously driven by the same transport, the first mentioned sheet being reinserted into the process path at the proper time for receiving the second side image before the arrival of the second sheet at the retime nip. Subsequent duplex sheets are handled in the same manner so that duplex copies are interleaved or otherwise reinserted into the process path with first side copies so that skipped pitches on the photoreceptor are minimized.

Abstract: A sheet feeding and separating apparatus for feeding sheets from a stack by exerting a drive force against the top sheet. The sheet is urged off the stack by a nudger roll toward a retard nip formed where a feed roll contacts a retard roll. The retard roll is movable relative to the feed roll, and thus is capable of producing drive forces of varying magnitude at the retard nip to propel a sheet toward the copying mechanism. A controller signals the nudger roll to urge a sheet off the stack and then monitors a sensor to determine whether the sheet passes through the retard nip. A misfeed condition occurs when the sensor fails to detect a sheet within a predetermined length of time. In response, the controller moves the retard roll toward the feed roll to increase the drive force exerted on the sheet. The retard roll is further adapted to detect the occurrence of a multifeed when multiple sheets contact the retard nip.

Abstract: A top vacuum corrugation feeder with optimized performance for a large variation in sheet sizes is obtained by adjusting the vacuum port area of a vacuum chamber simply by the action of adjusting the paper guides in the paper tray for different sheet sizes.

Abstract: An adjustable nudger roll for use in a friction retard feeder includes multiple springs used in conjunction with the nudger roll in order to allow greater latitude for adjustment of the normal force of the nudger roll against a substrate stack and in order to reduce the incidence of misfeeds. This arrangement adjusts the normal force on substrates as the requirement of the feed force changes and thereby reduces misfeeds and multifeeds.

Abstract: A feed roll wear compensating method and apparatus measures the surface speed of the feed and nudger rolls that are rotated by a motor and adjusts the motor speed to prevent sheet damage from occurring. The surface speed of each of the rolls is measured by sensors that detect the position of a moving sheet and the signal from the sensors is used to deduce the reduction in diameter of the rolls due to wear. The roll wear information is used to adjust the nominal elevator height to maintain constant force on the sheets and to provide feedback for adaptive control of the feed motor to adjust the speed of the feed roll.