ROTARY DRUM FOR IMAGE SCANNER

摘要

PURPOSE:To suppress the deformation of the drum without increasing the wall thickness of the cylindrical part and flange parts of the drum by adopting the constitution consisting in dividing a hollow chamber by a partition wall, communicating the inner hollow chamber with the atm. and evacuating only the inside of the outer hollow chamber to a vacuum. CONSTITUTION:The hollow chamber formed in the rotary drum 12 is segmented by the cylindrical partition wall 22 concentrical with a cylindrical body 20 to the inner hollow chamber 24 and the outer hollow chamber 26 and the inner chamber 24 is communicated with the atm. through a communicating hole 36. The inside of the outer chamber 26 is evacuated to a vacuum by a vacuum pump through a suction path 32 and the communicating path 34 and a sheet material 10 is sucked and held on the outer peripheral surface of the cylindrical part 14 through suction holes 36 of the cylinder 20. A negative pressure eventually acts only on the annular parts 40, 40' of the inner side face of the flange parts 16, 16' and the force to be applied on the flanges 16, 16' is decreased according to this constitution.