Patent GB-1326090-A (GB)
Title: Wrapping machines
IPC: B65B25/16
Filed: 1970-10-01
Abstract: 1326090 Wrapping loaves LA CELLOPHANE and L HADJIAN 1 Oct 1970 [15 Nov 1969] 46635/70 Heading B8C A machine for wrapping loaves comprises a device 38 for folding a wrapping film 31 into a tube having overlapping longitudinal edges, a pusher 7 for pushing a loaf through the shaping device 39 and into the tube, heat-sealing grippers 41 operative to close the tube behind the loaf during retraction of the pusher 7, and a heated block 57 for sealing the overlapping longitudinally edges of the tube. The next loaf to be wrapped abuts the transverse seal across the tube and pulls an appropriate length of film through the shaping device 38. Pusher 7.-The pusher 7 is carried by a carriage 9 having rollers 10 which run on rails (11, Fig. 4), and having a tail 15 with a vertical slot (15a) in which is engaged a pin (16) carried by an endless chain 61 driven by a motor 22. The motor 22 is energized to extend the pusher 7 by microswitches 5 mounted at a wall 3 against which a loaf to be wrapped is placed. The motor 22 is de-energized by means of a microswitch 23 which is contacted by a block 14, on the carriage 9, at the end of the return stroke of the pusher 7. Film supplying mechanisms.-The film 31 is drawn from a reel R supported on an idler roller 26 and a rollet 27 driven by a motor 29. Prior to reaching the shaping device 38 the film is trained around a guide roller 33 carried by a carriage 34 displaceable along a slide 35. The motor 29 is energized by a microswitch 39 contacted by the pusher-carriage 9 during extension of the pusher 7, and is de-energized by a microswitch 40 adapted to be contacted by the carriage 34 at the end of its stroke. Heat-sealing grippers 41 (see Figs. 6 and 8).- The heat-sealing grippers 41 are carried by levers 44 pivoted to a cross piece 45 and supporting rollers 48. Two of the levers 44 are interconnected by a spring 46 which acts to open the grippers 41. The rollers 48 engage ramps 49a formed on a part 49 supported by rollers (50, Fig. 9) running on angle irons (50a). The part 49 is connected to a rod 51 guided on bearings 52 and supporting a pivotal pawl 53. When the pusher 7 is extended, the tail 15 of the pushercarriage 9 rides over the pawl 53, but on retraction of the pusher, the tail 15 abuts the pawl 53 and pushes the rod 51 to the right, thus causing the rollers 48 to be urged together and close the grippers 41. The pawl 53 is pivoted clear of the tail 15 by a ramp 54 to permit full retraction of the pusher 7. An electromagnet 55 is operative to push the part 49 to the left (thus opening the grippers 41) and is controlled by a microswitch 56 adapted to be actuated by the pushercarriage 9. The grippers 41 are also operative to sever the tube. Loaf-guiding, and heat-sealing block 57.- After leaving the shaping device 38 the loaf passes between a lower driven roller 58 and an upper roller 59 rotatably connected to the roller 59 by a flexible shaft 68. A second flexible shaft 69 connects the roller 58 to a second upper roller 60 operative to press the wrapped loaf against the heat sealing block 57. The first upper roller 59 is carried by a carriage 72 displaceable along a vertical slide 74 by means of an electromagnet 77 controlled by a microswitch 78 adapted to be operated by the pusher carriage 9, thus lifting the roller 59 from the path of the pusher 7.