Patent GB-734334-A (GB)
IPC: B31F1/00
Abstract: 734,334. Machines for making tubes. S.A.F.F.A. SOC. ANON. FABBRICHE FIAMMIFERIED AFFINI. Sept. 8, 1953 [Oct. 4, 1952], No. 24874/53. Class 99 (2). [Also in Group XXX] Tubes for packaging are formed from sheets a of cardboard corrugated on one or both sides, e.g. that known as " Carbion," smooth cardboard, paper, wood or other cellulose fibre materials, on a machine comprising a loading device 1 for the sheets, a conveyer 2, a device 3 which applies a natural or synthetic adhesive to the opposed edges of the sheets, a bending device 4, a pressing device 7 for completing the butt joint between the edges of the sheets and an off-loading device 8 for ejecting the finished tubes from the machine. Loading device. The sheets a previously cut to size are inserted into a hopper 1, the bottom sheet of the pack resting on the bed 9 of the machine, and the angle supports 12, 12<SP>1</SP> forming the hopper being adjustable in the longitudinal and lateral directions so that the hopper can accommodate sheets of different sizes. An interchangeable, formed plate 18, Fig. 3 (not shown), flattens and lightly presses the edges of the sheets to remove small variations in the width of the sheets. Conveyer. An endless chain 2 runs in a slot 10 in the bed 9 of the machine and comprises links 15 engaging over sprocket wheels 19, 20, the wheel 20 being driven through a sprocket 20<SP>1</SP> and chain 21 directly coupled to a speedreduction motor unit. Plates 16, of a thickness suitable for that of the sheets a and the distance between which is variable, are secured to the links 15 and ensure that the sheets travel with the chain and along the machine. Adhesive applying device. Units 3, Fig. 4, disposed on either side of the machine and adjustable laterally, comprise vertical discs 23 which are driven through chains of gears 25 ... 28, and dip into baths 22 of adhesive and deposit adhesive onto the edges of horizontal revolving discs 24 which in turn apply adhesive to the edges of the sheets. The gears 28 are mounted for lateral adjustment on a shaft 29 driven from the sprocket 19 by a chain 31, and the disc 24 is mounted on a shaft 32 rotated through bevel gears 33 from a gear 35 meshing with the gear 26. Bending device. An interchangeable core 4, Fig. 6, fixed at one end to a support 41, Fig. 1, rests on the plates 16 and has an internal electrical heating resistance 42 for drying the adhesive on the internal surface of the tubes. The core which extends to the off-loading end of the machine forms an annular space with interchangeable and laterally adjustable guides 5, 5<SP>1</SP>, the sheets a receiving a slight bending in the guides and around parallel and adjustable bars 44, 44<SP>1</SP> which force the edges of the sheets to follow a predetermined course. The partially bent sheets are received in guides 6, 6<SP>1</SP> having semi-circular internal faces and wherein the bending of the sheets is completed by bring- ing the opposed edges of the sheets into contact. A plate 49 facilitates entry of the sheets under a pressure bar 7. Pressing device. The pressure bar 7, Fig. 6, comprises an element 7<SP>1</SP> of rectangular crosssection separated by a sheet 51 of insulating material from an element 50 of channel crosssection and enclosing an electrical heating resistance 52 which together with the heater 42 in the core 4 serves to produce the heat required for complete drying of the adhesive. The bar 7 is secured to a carrier 53 the elevation of which can be varied by verticalÀ screws 55, 551 rotatable through gears 58, 59 and by a handwheel 61 on a shaft 60 carrying the gears 59 and extending between supports 57, 57<SP>1</SP>. Off-loading device. A knurled roller 8, Fig. 1, having a surface speed greater than that of the conveyer throws the finished tubes into a collecting bin. The roller is driven by gears 62, 63 from a gear 64 secured to the shaft 65 of the sprocket 20. A counter 66 to register the number of tubes produced is located near the roller 8. In a modification, the guides 6, 6<SP>1</SP> are replaced by a pair of laterally adjustable endless chains 68, 68<SP>1</SP>, Fig. 7, the links of which are fitted with blocks 69, 69<SP>1</SP>. Plates 70, 70<SP>1</SP> are attached to the curved faces of the blocks and serve in conjunction with the plates 16 to push the tubes along the machine. The chains have the same speed and direction of movement as the chain 2 and are driven through sprockets and vertical shafts 74, 74<SP>1</SP> and 75, 75<SP>1</SP> from the main transmission of the machine. In a further modification an endless steel band 83, Fig. 9, the tension and height of which is adjustable, runs between the core 4 and bar 7 and is driven by a chain 96, tensioned by a device 102, from the gear 63, Fig. 1, driving the roller 8. A scraper 84, or a sponge wiper, cleans the band of deposits of adhesive.