Patent GB-1480980-A (GB)
Title: Automatic sheet changing system for reprographic machines
IPC: B41L29/14
Filed: 1975-08-01
Abstract: 1480980 Sheet changing in reprographic machines ING C OLIVETTI & C SpA 1 Aug 1975 [2 Sept 1974] 32340/75 Heading G2A A reprographic machine has a flexible support which winds from a feed reel to a take-up reel, and carries thereon sheets spaced along and interwound with the support, which sheets can be automatically supplied to and removed from a holder where the reprographic process is carried out. The machine is of the type in which a master sheet 4 of photo-conductive material is wrapped round a drum 3, and a latent image is produced thereon which is developed and then transferred to a copy sheet. Such a master may be used to make hundreds or even thousands of copies, after which it must be replaced. A series of masters is spaced along and interwound with a flexible support band 20 which winds from a feed reel 23 on to a take-up reel 24. The reels are formed on respective cylinders 13, 14 inside containers 5, 6 forming part of a cartridge 1. The cartridge can pivot open on a rod 31, and has means whereby it is correctly and positively located in position on the machine. When band 20 unwinds, it passes out through an opening 17 in container 5 and along the outer surface of container 6. When it enters container 6 through opening 18 it is turned sharply round the end 19 to wind on to cylinder 14 as shown. The sheets 4 are spaced regularly along the band, the distance between two consecutive sheets being greater than the length of a sheet. The drum 3 is keyed on a shaft 72, and has a shaped portion 73 having two inclined surfaces 74, 76. For normal copying operations the master 4 lies around the periphery of the drum, and is held thereon by a pair of wires 182, attached at their respective ends to spindles 46 and 111. The leading edge 190 of the master lies in the portion 73 and is held by a gripping element 89 forming part of a clamp 80. The rear edge 192 remains superposed over the portion 73. When it is desired to remove a master sheet and replace it with a fresh one, a key is pressed by the operator, which initiates a sequence of mechanical operations. The gripping elements 89 are pivoted up into the dotted line position, which releases the edge 190 of the master, and raises the edge 192. A pair of rollers 109 descend to co-operate with a pair of rollers 95, and between them the edge 192 of the master is advanced, guided by a plate 57, until it lies against the portion 29 of band 20, following the path 195 shown in heavy dashes. From here it is carried along by the band and wound on to reel 24. During this operation a fresh master 4 is gradually unwound from reel 23, and advances along the course 197 shown in heavy dashes, in position ready to be wound on drum 3 after the old master has been completely removed. Since the band 20 changes direction abruptly as it passes round the end 19 of opening 18, it separates from the master 4, which advances into the gap 67, pushed by rollers 44. By now, rollers 109 have been raised again into the position seen in the drawing. The leading edge of the master is once again gripped by the clamp element 89, and the drum 3 rotates in a clockwise direction until the master is fully wound round the drum. The rotation then ceases, the changing cycle now being at an end, and normal reproduction operations can be resumed. A counter and signal lamp may show when the last available master has been reached. The sequence of operations is controlled automatically by a system of cam-controlled mechanisms described in some detail.