GB937227A - Photographic printing machine for use with light-sensitive material in roll form - Google Patents

Abstract

937,227. Feeding webs. AGFA A.G. March 22, 1960 [March 26, 1959], No. 10193/60. Class 100 (1). [Also in Group XX] In a photographic printing machine, a device for advancing, step by step, a web of light-sensitive paper comprises a ratchet wheel 68 coaxial with a feed roller 23 (Fig. 6, not shown), and a spring-urged driving pawl (not shown), on an arm 67 which is oscillated about a pivot 66 by means of mechanism comprising two intermeshing gear wheels, a crank arm 10 fixed to the gear-wheel 65, two adjacent links 13, 12 articulated at a pivot 14 which is movable by means of a roller 15 in a fork 16, a pivoted bell-crank lever 7 having an arm 9 coupled to the link 12 and a fork 6 engaged by a roller 5 on a crank 2 which is driven by an electric motor 39. The fork 16 is fixed to a plate 56 pivoted in the housing of the machine and is adjustable by means of a manuallyoperable device 57-61 to several different positions corresponding to different step lengths. Spring catch means are provided for releasably retaining said fork in any of its several positions. The electric motor 39 (driven continuously) is coupled to said crank 2 by way of a worm gear 40, a chain 41, a sprocket 70 rotatable on the shaft 49 of the crank 2 and a plate 42 which is fixed on said shaft 49 and is coupled to the sprocket wheel 70 by a spring-coil friction clutch controlled by an electromagnet 48. In an alternative embodiment (Fig. 4, not shown), the plate 56 and fork 16 may be adjustable by means of a worm drive, in which case continuous step-length settings are possible, and the ratchet and pawl on arm 67 may be replaced by a roller wedge-locking device 30-32.