Method and device for feeding, aligning and holding a sheet on a sheet-processing machine

Method of feeding, aligning and holding a sheet on a cylinder of a sheet-processing machine, which comprises, prior to an occurrence of a gripping operation on a sheet at a cylinder of a sheet-processing machine, forcing a leading edge of the sheet into a contact position wherein the leading edge of the sheet is pressed against moving front lays which are guided over the cylinder, guiding the front lays around the cylinder, opening sheet grippers carried by the cylinder, inserting the leading edge of the sheet which is in the contact position into the sheet grippers, and maintaining the leading edge of the sheet in the contact position with the front lays until just before closing the sheet grippers.

Method of feeding, aligning and holding a sheet on a cylinder of a sheet-processing machine, which comprises, prior to an occurrence of a gripping operation on a sheet at a cylinder of a sheet-processing machine, forcing a leading edge of the sheet into a contact position wherein the leading edge of the sheet is pressed against moving front lays which are guided over the cylinder, opening sheet grippers carried by the cylinder, inserting the leading edge of the sheet which is in the contact position into the sheet grippers, moving the front lays between the grippers when inserting the leading edge of the sheet into the grippers, and maintaining the leading edge of the sheet in the contact position with the front lays until just before closing the sheet grippers.

Method of feeding, aligning and holding a sheet on a cylinder of a sheet-processing machine, which comprises, prior to an occurrence of a gripping operation on a sheet at a cylinder of a sheet-processing machine, forcing a leading edge of the sheet into a contact position wherein the leading edge of the sheet is pressed against moving front lays which are guided over the cylinder, opening sheet grippers carried by the cylinder, inserting the leading edge of the sheet which is in the contact position into the sheet grippers, maintaining the leading edge of the sheet in the contact position with the front lays until just before closing the sheet grippers, and moving the sheet at a speed higher than the speed of the front lays while continuously braking the higher speed of the sheet against the front lays.

Method of feeding, aligning and holding a sheet on a cylinder of a sheet-processing machine, which comprises, prior to an occurrence of a gripping operation on a sheet at a cylinder of a sheet-processing machine, forcing a leading edge of the sheet into a contact position wherein the leading edge of the sheet is pressed against moving front lays which are guided over the cylinder, opening sheet grippers carried by the cylinder, inserting the leading edge of the sheet which is in the contact position into the sheet grippers, maintaining the leading edge of the sheet in the contact position with the front lays until just before closing the sheet grippers, and laterally aligning the sheet while its leading edge is in the contact position with the front lays and prior to closing the grippers.

Device of feeding, aligning and holding a sheet on a cylinder of a sheet-processing machine, comprising means for feeding a sheet, means including front lays for aligning the sheet at a leading edge thereof, means for guidingly moving said front lays from a location forward of a cylinder of a sheet-processing machine, as viewed in a sheet travel direction through the machine, to a location above the cylinder, and gripper means having open grippers closable for gripping the sheet at a leading-edge portion thereof, a leading edge of the sheet being feedable by said feeding means into contact with said front lays of said aligning means, and a leading-edge portion of the sheet being insertable into said open grippers while the leading edge of the sheet remains in contact with said front lays of said aligning means and prior to a closing of said open grippers.

Device for feeding, aligning and holding sheet on a cylinder of a sheet-processing machine, comprising means for feeding a sheet, means included front lays for aligning the sheet at a leading edge thereof, and gripper means having open grippers closable for gripping the sheet at a leading-edge portion thereof, a leading edge of the sheet being feedable by said feeding means into contact with said front lays of said aligning means, and a leading-edge portion of the sheet being insertable into said open grippers while the leading edge of the sheet remains in contact with said front lays of said aligning means and prior to a closing of said open grippers, said aligning means comprising a conveyor-belt device running over the cylinder.