GB665940A - Improvements in machines for producing patterns photographically on the surface of copper and like rollers - Google Patents

Abstract

665,940. Photo-mechanical printing surfaces. FRANK, L. July 20, 1950 [July 18, 1949], No. 18823/49. Class 98 (ii). A machine for photographic reproduction of patterns or designs on rollers as of copper comprises jacks supporting the ends of a mandrel carrying the roller at an adjustable height, a transparent cover to pass over the roller and hold a transparency of the pattern or design thereon, clamps beneath the roller for holding the ends of the transparent cover, and means for simultaneously raising the jacks to apply resilient pressure to the roller for tensioning the cover. The mandrel ends may be carried on rollers in the jacks to allow free turning and prevent uneven tensioning of the cover; and the jacks may be raised by rack and pinion mechanism acting through springs or by hydraulic means giving equality of tension. As shown, the mandrel ends b of roller c are carried by rollers d at the tops of jacks a; the transparent cover is clamped by a pair of bars in channel members, the front one of the pair being shown at m; hand wheels o on columns p are provided to give a preliminary tightening of the cover by raising jacks a and then the latter are further raised under uniform tension by operation of handle x to turn shaft w and hence a pinion v for each jack which raises racks u acting through springs (not shown) on the lower ends of the jacks. Ratchet mechanism y, z releasable by foot pedal 2 is provided to hold the jacks in the positions they have attained by manipulation of handle x. The Provisional Specification indicates, also, a method of raising the jacks simultaneously by use of two cams on a common shaft turned by a handle.