A sheet handling apparatus for a printing system includes a rotary drum having an inner chamber circumferentially surrounded by an outer peripheral wall with perforations formed therein. By means of sucking an air flow through the perforations of the drum to a suction system, sheets are attracted to the peripheral wall of the drum. A stationary shutter member is positioned inside the inner chamber for blocking the flow of air through the perforations when they pass, with the rotation of the drum, through a first predetermined angular range. The shutter member includes protrusions while the rotary drum includes recesses for receiving the protrusions, such that a meandering air flow passage is formed between the shutter member and the rotary drum. As such, friction between the rotary drum and the stationary shutter member is reduced, thereby reducing the power consumption of the suction system.

An apparatus is disclosed. For example, the apparatus includes a paper feed to feed print media a single sheet at a time, a plurality of rotating discs, wherein each one of the plurality of rotating discs comprises an elastomer ring to secure a leading edge of the single sheet against a registration wall and initiate a flipping process, an air duct to force an air flow towards the print media to levitate a trailing edge of the single sheet during completion of the flipping process, and a movable platform to hold a stack of the print media.

A paper feeder for transporting paper sheets, includes: a head fan that blows air on the paper sheets; a suction fan that applies negative pressure to the paper sheets blown by the head fan; a switching member that changes the direction of the air from the head fan; a head shutter that blocks the flow of the air directed by the switching member; and a hardware processor that determines the blocking time of the airflow, wherein the switching member changes the air direction between a first direction for floating the paper sheets and a second direction toward the suction fan, and the hardware processor determines stop timing of the air blow in the second direction directed by the switching member as the start timing of clocking the blocking time of the airflow, based on the weight and the resistance to an external force of the paper sheets.

A sheet handling apparatus for a printing system includes a rotary drum having an inner chamber circumferentially surrounded by an outer peripheral wall with perforations formed therein. By means of sucking an air flow through the perforations of the drum to a suction system, sheets are attracted to the peripheral wall of the drum. A stationary shutter member is positioned inside the inner chamber for blocking the flow of air through the perforations when they pass, with the rotation of the drum, through a first predetermined angular range. The shutter member includes protrusions while the rotary drum includes recesses for receiving the protrusions, such that a meandering air flow passage is formed between the shutter member and the rotary drum. As such, friction between the rotary drum and the stationary shutter member is reduced, thereby reducing the power consumption of the suction system.

A printing system includes an endless metal transport belt for transporting sheets in a transport direction, wherein the metal transport belt comprises multiple through holes through which an underpressure or overpressure may be applied on the sheets, a sheet separation system for separating the sheets from the metal transport belt by applying a local overpressure, and a sheet separation guide which guides the separated sheets away from the metal transport belt. The sheet separation system includes a stationary sliding surface, wherein the metal transport belt slides over the stationary sliding surface, wherein the stationary sliding surface includes a number of blow holes which define the overpressure zone, and wherein the blow holes are configured to apply a local overpressure in the overpressure zone through the metal transport belt onto the underside of the sheets. The overpressure zone is formed in the curved part of the stationary sliding surface, wherein the overpressure zone has an upstream end and a downstream end, which are defined by the location of the blow holes, and wherein the sheet separation guide directly adjoins the overpressure zone at the downstream end thereof.

Examples include a machine assembly for conveying sheet-format substrates, including a first belt conveyor and a second belt conveyor. These belt conveyors each have a continuously circulating transport belt and are arranged one after another in the transport direction of the substrates conveyed on the respective transport belt. The substrate to be transferred from the first belt conveyor to the second belt conveyor is lifted off the transport belt of the first belt conveyor by means of an air current generated by a lifting nozzle and an opposing air current generated by a counter-nozzle. The substrate to be transferred remains fixed until its transfer by the vacuum pressure generated by a suction chamber of the first belt conveyor. This suction chamber fixing the substrate is arranged close to the lifting region. Examples also relate to a printing machine comprising this machine assembly.

Examples include a machine assembly for conveying sheet-format substrates, including a first belt conveyor and a second belt conveyor. These belt conveyors each have a continuously circulating transport belt and are arranged one after another in the transport direction of the substrates conveyed on the respective transport belt. The substrate to be transferred from the first belt conveyor to the second belt conveyor is lifted off the transport belt of the first belt conveyor by means of an air current generated by a lifting nozzle and an opposing air current generated by a counter-nozzle. The substrate to be transferred remains fixed until its transfer by the vacuum pressure generated by a suction chamber of the first belt conveyor. This suction chamber fixing the substrate is arranged close to the lifting region. Examples also relate to a printing machine comprising this machine assembly.