GB962177A - Packaging machine - Google Patents

Abstract

962,177. Forming bags; seaming non-metallic sheet material. BARTELT ENGINEERING CO. Inc. March 29, 1962 [April 19, 1961], No. 12120/62. Headings B5D and B5K. [Also in Division B8] Separating and conveying bags connected at their edges; opening bags.-After bags have been cut by a cutter 140 (Fig. 13) from a continuously moving series 34 of bags connected at their edges they are delivered to a faster moving carrier 46 by an accelerating device 164 which accelerates the severed bags to a speed higher than that of the carrier 46. In the form illustrated the carrier 46 consists of a pair of vertically spaced endless chains 194, 194<SP>1</SP> (Fig. 16) joined by blocks 200 carrying grippers 50, 501 for engaging the front and rear edges of the bags. Each gripper comprises a blade spring 215 (Fig. 14) which presses the bags against a block 213 but can be released by a cam 223 controlled through a lever 220 and a roller 225 from cams 226<SP>1</SP> (Fig. 13). The rearward grippers 50<SP>1</SP> (Fig. 16) can be turned about pivots 227 under the control of rollers 228 engaging cams 232 to effect the initial gripping, to open the bag by pushing its edges inwardly, and to close the mouth of the bag, by tensioning it, when it is to be sealed. The chains are guided by members 196, 196<SP>1</SP>, 205, 2051 (Fig. 18) and, where the lower guides have to be interrupted to permit feed of the bags to the grippers 50, guiding blades 209<SP>1</SP> project forwardly from one end of the interrupted guides. The accelerating device 164 consists of rollers 165 ... 168 pressed against the bags and driven at such a speed that each bag is crumpled as it is delivered to a gripper 50. The rollers 165, 166 engage the bag before it is cut off by the cutter 140, slipping temporarily on the bag surface. The cutter 140 comprises a rotary member 142 carrying blades 146 and a rotary member 141 carrying anvil members 147. The blades 146 and anvils 147 are similar and can be turned to any of four positions to provide fresh working surfaces. Blades 233, 235 (Fig. 10) hold the upper margins of the bags apart before and after cutting off. The welds 36 (Fig. 3) stop short of the upper margins to permit this. In the vicinity of the cutter 140 the upper margins are held apart by a rotating disc 238 (Fig. 11) formed with gaps 236 to permit passage of the cutting blades. The rubber covering 66 (Fig. 9) is omitted from the lower part 43 of the feed rollers to avoid excessive creasing. Welding flat bags from webs. Closing bags.- The bags are formed by transverse welds 36 (Fig. 3) across a web 34 of sheet formed of, or coated on one side with, a thermoplastic material and folded as shown at the left-hand side of Fig. 3 by a fixed triangular folding plough flanked by a pair of folding rollers (not shown). Several welds are effected simultaneously by welding bars 71 (Fig. 8) supported above and below on carriers 100 carried by front and rear chains 72, 73 so that they travel with the web during welding and are then retracted and returned for a further operation. The welding bars 71 on one carrier 100 are spring mounted. A sheet 115 of heat-resistant material separates the heads 71 from the web to be welded and is tensioned by blade springs 116. A similar welding device sealing the upper edges of the bags after filling omits the lower set of chains 72, 73 and has the welding rods 71 disposed horizontally. The machine cannot be stopped with the welding heads in welding position. Manual clutches enable the carriers 100 for the welding heads to be adjusted into synchronism. Specification 962,176 is referred to.