Patent GB-935129-A (GB)
Title: Paper feed for high speed printers
IPC: B41J11/30
Filed: 1961-07-19
Abstract: 935,129. Typewriters. G. G. TURNER (Anelex Corporation). July 19, 1961, No. 26129/61. Class 100 (4). Pin-tractor web feeding arrangements.-A high-speed printer having a paper feed, includes an infeed pair of laterally-spaced tractors, an outfeed pair of laterally-spaced tractors, each tractor gripping an appropriate margin of the paper and, when driven, positively advancing the paper relative to it, a drive for said tractors, and means to affect the lateral positions of the tractors, engaging one edge of the paper, independently and/or together with the tractors engaging the other edge thereof, said tractor positioning means being operable while said tractor drive is in operation. Each paper feed assembly consists of a pair of tractors 65, 64 (Figs. 1 and 14), having hinged covers 67, 66, which swing open, permit a sheet of paper to be placed therein with its marginal perforations engaged by pins 68 carried by arms of attached to chains 70 trained over sprocket 74, engaging a driven square shaft 79 on the outfeed side and a drive shaft 78 on the infeed side and, an idler 75. The shafts 78, 79 are interconnected by a belt 120 in Fig. 2, and the paper feed assembly is driven through a sprocket 86 by a formal control drive 31. Transverse adjustments.-For lateral adjustment of the tractors, each one is provided with a fixed nut 76, in Fig. 14, one of which on the outfeed side is threaded on a screw 165 formed with an extension 167 extending through a screw 168 (Figs. 7 and 8), carrying a complementary nut 76 of the tractor 65. The screw 168 has a sprocket 170 and a gear 171 fast on its outer end and the exposed end of shaft 167 is provided with a sprocket 174 and a gear 175. The gears 171 and 175 are in mesh with gears 188 and 189 mounted on a shaft 178 arranged for transverse movement, with the shaft provided with a hand-operated knob 179 on one end and three axially-spaced grooves 180, 181 and 182 on the other end and the shaft's axial movement is prevented by a detent 183 engageable with any one of said grooves. To shift the shaft 178 axially from the position in which its gears 188, 189 engage gears 171, 175, respectively, into two other positions in one of which the gears 188 and 171 are in mesh only, and the other of which the gears 189 and 175 are in mesh only, so that either or both tractors of both assemblies may be moved towards or away from each other, by rotating the handled knob 179, a mount 191 (Fig. 6, not shown), supporting a knob 193 is provided, the rotation of the knob in conjunction with a cam 194 (Fig. 7), located between and engaging the proximate faces of the gears 188, 189, determining the axial displacement of the shaft and consequential engagement of the selected gears. The lateral movement of the tractors of the infeed assembly and mounted on shafts 140, 143 constructed in a similar manner to shafts 165, 168, is imparted by a chain and sprocket arrangement shown in Fig. 7, viz. chains 177, 157 and 155 in conjunction with sprockets 174, 164 . . . 153 and 146 operate the tractor 64 and the chains 176, 156 and 152 in conjunction with sprockets 170, 162 . . . 150 and 145 operate the tractor 65. Sheets tensioning arrangements.-To increase or decrease the tension of the moving paper there is provided a knob 130 having an adjusting screw 129 (Fig. 9), so that rotation of the knob imparts a counter movement to slides 123 and 126, pivotally supported by pivot 138, and carrying on shafts 122 and 127, sprockets 120 and 121, respectively, whereby raising of the slides 123, accompanied by simultaneous lowering of the slides 126, results in the tensioning of the paper by relative counter-clockwise angular displacement of the pinion 119 on the driven shaft 79. Coupling arrangements.-To facilitate raising or lowering of the paper so as to properly locate its transverse lines relative to the print hammers, there is provided a knob 111 with a screw 106 attached to a fork 100 pivotally supported by a pin 97 so as to impart a counter movement to slides 92 and 95 carrying on shafts 91, 94, sprockets 89, 90. When the screw 106 is turned in a clockwise direction, the fork 100 is tilted to thereby raise the sprocket 90 and lower the sprocket 89, thus effecting lowering of the paper by relative clockwise angular displacement of the sprocket 86 on drive shaft 78. The fork carries a finger 112 extending through a slot 113 in a cover 109 provided with indicia, corresponding for the transverse lines of the paper with reference to which the finger is readable. Line spacing.-The spacing between the lines of printing is governed by the time between a starting and a stopping pulse, the former of which originates in the data producing system and the latter is initiated by a photo-cell unit 202 (Fig. 2), the light to which is admitted by a lamp 202 via apertures 201 in an endless tape 201 driven by a sprocket 200 connected to the format controlled drive 31.