Patent GB-529051-A (GB)
Title: Improvements in or relating to sheet-feeding mechanism for printing machines
Filed: 1939-05-10
Abstract: 529,051. Photo-electric sheet-feeding devices for statistical machines. BRITISH TABULATING MACHINE CO., Ltd. May 10, 1939, No. 13994. Convention date, May 11, 1938. [Class 106 (i)] [Also in Group XL] A sheet-feeding mechanism for line-spacing and long-feeding in printing and like machines comprises means for automatically printing a mark for each line the mark being thereby gradually extended as the successive lines are printed, and photo-electric means sensitive to reflection from the sheet adapted to be set in operation when the mark passes beyond the optical field to cause the cessation of longfeeding. The sheet, Fig. 2, may be first provided with mark 105 extending to a length corresponding to the heading of the card ; or this mark may be made by feeding the card through the machine by hand until the first blank line is reached, the-mark being extended by successive printing at each step of the hand feed corresponding to a line-space. Then, when the machine is operated and successive lines printed, at each line-spacing operation a further imprint is automatically made to increase the length of the mark as shown at 106 to an extent equal to the spacing of the number of lines printed. Any sheet thus printed and marked, when again inserted in the machine, will be fed in step by step until the photo-electric device operates to stop the machine at the first blank line determined by the end of the mark 105, 106. The photo electric device, Fig. 3, comprises a lamp L and a lens 121 directing a beam of light to the point X on a platen 16, and a lens 124 with a hood 123 directing the reflected light to a photo-cell 125. This device is mounted on a plate 116 fastened to the machine frame 115 by bolts 119 passing through arcuate slots 117, 118 allowing adjustment about the point X. The lens 124 and the cell 125 are also adjustably mounted and clamped by means of bolts 129, 128. The device for printing the mark 105, 106, comprises rollers 142, 141 on a bracket 138 pivoted at 136 to a plate 135 fastened to the machine frame 115. The bracket carries an ink well 148 from which ink is transferred by roller 141 to roller 142, which makes the mark on the sheet over the platen 16. The armature 144 of an electromagnet SM is attached to the bracket 138 and is normally attracted by its electromagnet against the action of a spring 150 to hold up the roller 142 away from the platen 16. At the desired moment in the operation of the machine, the circuit of the electromagnet is broken to allow the bracket to swing down to bring the roller 142 down on the platen at a point Y to make a mark on the sheet. The distance between X and Y corresponds to the control lag of the apparatus. The devices mentioned above are described in connection with the tabulating machine of Specification 375,889 controlled by perforated record-cards to print, add, subtract and compute balances and totals of the amounts represented on the cards, and in addition to print alphabetical information. The machine includes: means for line-spacing comprising a pawl and ratchet device and an electromagnet controlled by a cam ; means for long-feeding and ejecting comprising a clutch on the platen shaft controlled two electromagnets, one for engagement and one for disengagement; a feeler for closing a switch when a sheet is inserted into the machine to initiate sheet feeding and set the photoelectric device in operation ; and brush contacts at the end of the platen to cause the declutching of the feeding means when a sheet passes away.