GB944847A - Packaging method and machine - Google Patents

Abstract

944,847. Packaging. PACKAGING FRONTIERS Inc. Sept. 19, 1960 [April 4, 1960], No. 32106/60. Heading B8C. A machine for producing tetrahedral packages, by forming a web of packing material around a combined filling head and mandrel, has sealing means for forming transverse seals across the tube alternately at right angles to each other above the level of the product and means to feed the tube intermittently downwards. The machine produces two or more packages simultaneously each of which may be a single tetrahedron pack or a double pack containing different products as shown in Fig. 13. Tube formation.-Heat-sealable webs are fed from rolls 11, 11a to formers 18, 18a (Figs. 2 and 3), which wrap the webs around the mandrels 20, 20a to form tubes having flanges 14c (Fig. 4), which are heat-sealed by pairs of sealing jaws 23, 23a, the jaws being mounted on pivot-pins 26, 26a in a scissors-like arrangement. The two pairs of jaws are linked for simultaneous movement by a rod 34. When each seam 14d leaves the sealing jaws it is in a radial position relative to the tube, but it is then folded down against the wall of the tube by idler rollers 67, 68 (Figs. 3, 12a). The transverse sealing means (Figs. 2, 5) consists of a carriage 37 mounted on four rotatable and vertically movable shafts 38, 58. A crank 39 in the form of a disc having a pair of crank pins 40 is mounted on the top of each of the shafts 38. Pivotally connected to each one of the pins 40 is an arcuate connecting link 41, the other end of each connecting link being connected to one of two bars 42, 42a, one either side of a frame member 43. A bar 44a is rigidly attached, by means of rods 47 which slide freely through bars 42a and frame member 43, to the bars 42. Bar 44 is similarly attached to bar 42a. The bars 42, 42a, 44, 44a each support a sealing jaw 45 or 45a. On rotational oscillation of the rods 38 the cranks 39 cause each of the pairs of sealing heads 45, 45a to move together and then to separate again, thus transversely sealing the web tubes. Sealing jaws 53, 53a mounted at a lower level on bars 54 are similarly connected by cranks 57 to rods 58. Scissors-like cutting blades 61, 62 (Fig. 2), sever a double pack simultaneously from each sealed tube. In a modification (Figs. 14, 15, 17, not shown), pneumaticallydriven cutters are mounted within one of each pair of sealing jaws, each cutter entering a slot in the other jaw of the pair and single packages being severed from each tube. A stripping means for stripping the web from the transverse sealing jaws when these incorporate cutters may be provided this taking the form of a pair of rods 168 worked by an over-centre action of a spring 174 and abutments 177, 168 on the jaws themselves (Fig. 16). Package filling.-The product to be packaged, e.g. a liquid is delivered through a known metering valve 36 through tubes 21, 21a. If the machine is used to produce double packs (shown in Fig. 13) containing two different products, a second set of tubes 21, 21a and metering valve 36 is provided, the two sets working alternately between successive transverse sealing operations. In a modification (Fig. 19, not shown), air at a pressure slightly above atmospheric is introduced into the mandrel, this slight pressure being sufficient to distend the filled tube prior to sealing, thus ensuring that the transverse seals are free from wrinkles. Web feed and transverse sealing synchronization.-Each web has printed on it indicia 135, as shown in Fig. 13, for scanning by photoelectric eyes 137, (137a), (Fig. 2). The carriage 37 is adjusted to pull down slightly over a package length on each stroke, and when this overrun accumulates sufficiently to displace the mark 135. from out of the beam of the eye a solenoid 140, 140a (Figs. 3, 4), is energized which by means of a lever 142, 142a, lifts the pivotpin 26, 26a slightly when the sealing jaws 23, 23a are being operated, thus raising the jaws to pull back the web and correct the overrun. As an alternative, the carriage could pull off under a package length and the jaws pull down the webs. Each web is adjusted independently. The web may carry graduations to indicate the amount of contents remaining in a partly used package.