GB978767A - Improvements in or relating to apparatus for use in the preparation of printing master sheets for hectographic or lithographic printing processes - Google Patents

Abstract

978, 767. Continuous treatment developing apparatus for printing with light sensitive sheets. W. RITZERFELD, and G. RITZERFELD. March 20, 1963 [March 23,1962; Oct. 16, 1962], No. 11004/63. Heading G2A. A continuous treatment motor driven developing apparatus for light sensitive sheets for use in the production of hectographic or lithographic printing master sheets where the light sensitive sheet is used as the master sheet or is used to convert a further sheet into a master sheet, has liquid developer 49 in a container 8 through which extends a guide channel 13,14 for the sensitive sheet 48 with feed rollers 33, 34 at its entrance and feed rollers 37, 38 at its exit which press an additional sheet from feed plate 20 into contact with the developed sheet 48. The passage of master sheet 48 over feed plate 15 raises sensing rollers 17 carried between levers 25 pivoted at 27 between side walls, 2, 3, whereby feed plate 20, through parts 28, 29, 26, 25 is raised with roller 32 also mounted on levers 25, and the drive for the contact sheet is thus disengaged. Counterweights 23 now rotate shaft 21 and at the end of plate 20 until pins 24 rest on levers 25 and the stop 22 projects upwards to form an abutment for a contact sheet which may then be placed on plate 20. Master sheet 48 passes through developer 49 until its trailing edge clears rollers 17 which then fall into slots 16 in plate 15, the movement of levers 25 releasing stop 22 and also re-engaging roller 32 with roller 35 to transport the contact sheet to rollers 37, 38 to meet the master sheet 48. The sheets are separated by hand on leaving these rollers, and sheet 48 is then placed layer side up on the portion 7a of hood 7, upon the protector sheet 50 of an ink transfer sheet 52 whose end has been inserted through slit 51 in the hood. The sheets are then fed through the rollers 37, 38 and are separated by hand to give a mirror image master sheet. The rollers 17 are adjustable in slot 30 to suit different sizes of sheet. In an alternative procedure, the developed sheet 48 is brought into contact with an ink transfer sheet and passed through rollers 37, 38. After separation, the ink sheet is fed through rollers 37, 38 with a blank paper sheet which is separated to form a further master sheet. In another embodiment, a spring loaded pivotable holding bridge is mounted near the slot 51 and holds ink sheet 52 in its folded back position to prevent premature contact with sheet 48. A rubber pad carried on an upwardly pivotable lever 10 provided to hold the protective sheet 50, until master sheet 48 is inserted into the ink sheet set 50, 52. Wire bridges are provided to support the sheets leaving rollers 37, 38, and to support the folded back sheet 52.