Patent GB-460368-A (GB)
Title: Improvement in bag making machines
IPC: B31B37/00
Filed: 1935-06-21
Abstract: 460,368. Making paper &c. bags. SMITHE MACHINE CO., Inc., F. L. June 21, 1935, No. 17912. Convention date, July 13, 1934. [Class 94 (ii)] In a bag-making machine there is provided in combination a web supply reel, tube-forming mechanism, means for feeding the tube of material intermittently to a cutter, which severs elementary tubular blanks while the tube is idle, and power means comprising intermittently rotating feed rollers, controlled by the web, for drawing the web from the supply reel. A web 1 of transparent or opaque paper from a reel 2, braked by a weighted band 21, 23, is fed past a gumming device wherein a disc 29 applies gum to a longitudinal edge and thence around a roller 31, which rocks under gravity about a shaft 61 to produce a slack portion in the web intermittently advanced by feed rollers 37, 38 about a tube forming device 34, 36, the formation being assisted by arms 35 and a hold-down plate 38b. The feed rolls 27, 28, driven from a shaft 68 by a chain 81, operate to gain a little on the feed rolls 37, 38 so that when. slack has been formed the roll 31 will descend and in so doing will operate a clutch bell-crank 64, 66 to disengage the clutch member 75 from the driven member 76. The intermittent feed rolls 37, 38 then operate to utilize the slack produced, the roll 31 is raised and the clutch 75, 76 re-engaged to drive the feed rolls 27, 28. The rolls 37, 38 are driven by a rack-and-pinion 47,48 (actuated adjustably by a crank disc 46) through a chain 53 which drives a ball-clutch on the shaft 40 of the roll 38 in one direction only. By reason of the rack- and-pinion mechanism, the speed of the feed rolls 37, 38 is accelerated and retarded from and to rest. The leading end of the tube is then sheared by blades 90, 91 attached to slides 92, 93 operated by a cam 106 through a spring- biassed lever-system 95, 97, 100, 102, 104, the links 97, 102 engaging by a pin-and-slot joint. The edge of the upper blade is inclined so that shearing is effected from side-to-side of the tube. Tucker blades 9, adjustably attached to a bar 114 by slotted arms 112, and actuated by a cam 117 through a spring-urged lever system 119, 121, 122, bevels 124, 125 and universal joints 129, 132 next fold the leading corners of the tube into the space 44 in the end of the former plate 8. The tucked end passes between rolls 135, 11 which do not grip it, but a suction passage 136 in the top roller folds back the upper tab 133 of the tube, which is held back in passing between rollers 138, 139. A roll 150 and feed segment 151, supported in a spring- urged rocking frame 153 actuated by a cam 161 next feed the blank forward to feeding pairs 163, 164 and 165, 166 which may be adjustable with reference to the length of bag being made. The lower tab 134 is creased by a cam-operated gripper roll-pair 15, 16 and gum is applied in four triangular areas 190 ... 193 by pads on the roll 15 fed from a bath 189, the tucking blade on the cylinder 15 being retracted to avoid the gumming thereof. A pressing segment on the roll 196 presses the folded bottom tab 134 and strippers 201 engaging in grooves in the roll 16 remove the bag blank to belts 17, 18 which lead over a curved roller bed 206. A cam-operated tucker blade 19 and a spring- urged pressing blade 20, actuated by a cam 223 and a cam plate 219 move to fold over the following tab 133 and iron the same. If a printed web is to be used, an adjustable device, under the care of the operator, is fitted to vary the throw of the rack bar 47 so as to feed the printed areas accurately with regard to the cutting and folding devices. Specification 437,449 is referred to.