Improvements in or relating to vacuum frames for printing upon sensitised surfaces used in connection with photomechanical composing machines for multiple reproduction on zinc plates, lithographic stones or the like

摘要

369,109. Photographic printing apparatus. MARINONI (MACHINES ET MATERIEL POUR L'IMPRIMERIE ET LES INDUSTRIES ANNEXES), 96, Rue d'Assas, Paris. July 6, 1931, No. 19441. Convention date, Aug. 21. 1930. [Class 98 (ii).] Apparatus for printing on zinc plates, lithographic stones, and the like, especially for step-and-repeat printing comprises a frame having a glass plate mounted therein and held in place by a rubber housing having a flexible lip adapted to bear on the surface of the plate or stone, the space thus formed being evacuated. The negative to be reproduced is mounted on the surface of the glass plate, and a band or bar is inserted in a recess in the housing to press the lip outwards according to the thickness of the document. In the form shown for reproducing a thick document 16, a broad bar 15 is inserted in the recess in the housing 5. The glass plate 3 bearing the negative 16 is secured in the frame 1 by means of the housing 5 which is clamped to the frame by a block 6. The lip 9 bears on the surface of the printing plate 4, the space within the housing 5 being evacuated through the pipe 13.