GB1507938A - Register control system for a moving web - Google Patents

Abstract

1507938 Register control scanner for moving web HURLETRON ALTAIR 17 July 1975 29995/75 Heading G1A [Also in Division G3] Such a scanner for sensing the passage of marks 61-64 on web 10, whose path is illuminated and which reflect light to be sensed by electric circuitry producing scanning pulses for controlling register, comprises a flexible light conduit element as 73, 74 with incoming 71, 72 and outgoing 77, 78, light paths at the end remote from the path of the marks and a rigidifying arm as 121, 122 connected with the end adjacent to this path to retain it in scanning relationship with this path. Elements 73, 74 are bendable and twistable relative to the ends remote from the path of the marks and comprise optical fibres randomly distributed between paths 71, 77 and 72, 78 respectively, the adjacent ends being shaped like marks. Servomotor 22 is coupled to both the sidelay adjustment mechanism of printing cylinder 14 and sleeve 18, which thus move in step. Sleeve 18 slides on mounting bar 16 secured to the frame of printing apparatus and carries scanner box 45 containing source 70 and photocells 81, 82, and scanner elements 20 and 46 adjustable so as to position apertures 50, 51, whose thickness to width ratio is small, the thickness being small enough to enable resolution of markes spaced by 1 mm, the phase difference of the optical pulses from which indicates the degree of lateral register between web 10 and cylinder 14 and can actuate motor 22 to adjust it. Manually operated screw assemblies 111, 119, 120 for riders 110, 116, 117 engage V shaped notch 114 in sleeve 18. Arms 121, 122 are angularly adjustable relative to riders 116, 117 and adjustment bracket 126 provides longitudinal position adjustment of aperture 51 by knob 127. Tubing 131 supplies purging air.