Photographic copying machine

摘要

Apparatus for transferring photosensitive sheets from the transporting plane into the copying plane of a photographic copying machine has a suction chamber with a perforated cover having a flat upper side which defines the copying plane. The interior of the suction chamber is subdivided into one or more centrally located primary sections which are in direct communication with the intake of a suction pump and two or more secondary sections which communicate with the primary section or sections by way of narrow passages defined by internal partitions of the suction chamber so that a sheet which is advanced in the transporting plane to a position of register with the cover is attracted first to that portion or those portions of the cover which overlie the primary section or sections and thereupon to those portions of the cover which overlie the secondary sections. The number of primary and secondary sections which communicate with the intake of the suction pump is reduced when the apparatus is used for transfer of smaller sheets. The number of perforations per unit area of that portion of the cover which overlies the primary section or sections is greater than the number of perforations per unit area of that portion of the cover which overlies the secondary sections, and the combined cross-sectional area of perforations in communication with the primary section or sections is greater than the combined cross-sectional area of passages between the primary and secondary sections.