Patent GB-896270-A (GB)
Title: Method and apparatus for the production of tetrahedron-shaped packages
IPC: B65B9/20
Filed: 1960-07-01
Abstract: 896,270. Packaging machines. HERMORION Ltd. July 1, 1960 [July 4, 1959], No. 23158/60. Class 94(1). A tetrahedron-shaped package is formed by winding a web 5 of material helically to form a tube 10 on a mandrel 9 by the intermittent action of an endless belt 17 one run of which is passed round the mandrel 9, the tube 10 being sealed by jaws 11, 12 along zones transversely of the tube axis and in planes angularly displaced from each other thereby enclosing liquid filling supplied through a pipe 16, and the packages are finally separated by cutters 14, 15. Web control and supply. Means are provided at 87 for sensing the length of web material necessary for forming a package, either by a measuring wheel 88 or by photo-electric means (not shown). The means operate an electromagnetic clutch, Fig. 9 (not shown), thereby temporarily disconnecting the drive to a pulley 54 which drives the belt 17. The web 5, comprising paper coated with a heat-sealable plastic is unwound by rocking levers, Fig. 10 (not shown), from a roll 4, Fig. 4, housed in the frame body 2 on a hinged carrier 36. It is supplied via pulley rollers, through the top of the body 2, and across rollers 7, 8 to the mandrel 9. In a modification, a rotating mandrel effects the helical winding of the web material. Guiding, scoring, and seaming. A combined guiding and scoring means 52 has rollers engaging opposite faces of the web 5 and an annular scoring ridge marking off a web margin which is folded over so that a plastic-to-plastic seam may be effected. A further guide 18 having rollers 21 feeds the web 5 on to the mandrel 9 against which overlapping helically wound web-strips are seamed by heat and pressure by an element 22 swung into position, when the tube 10 is stationary, by means of cam mechanism operated by the movement of the jaws 11, 12. Sealing, filling and cutting. The tube 10 is sealed between jaws 11, 12 which reciprocate in a frame swingably suspended on arms 107, 109, the outer jaw 12 having horns 23, 24 for folding the web material above the seal as the seal is effected. Between each sealing, the tube 10 is rotated through 90 degrees. The jaws 11, 12 are operated by toggle mechanism, the drive being taken from a cam disc fixed on the main shaft 77 constantly driven by an electric motor 79. As the jaws 11, 12 close, the frame is pivoted slightly upwards so compensating for the reduction in the length of package material caused by the sealing. Filling through the pipe 16 may be either continuous or intermittent, the sealing being carried out below or above the filling material level respectively. The lower end of the pipe 16 is fitted with a non-return valve 23; a second valve 155 allows escape of gas. The pipe 16 is connected movably through a coupling 150 to a supply line 151 fitted to the outlet of a reciprocating pump 152. An electromagnetic blocking device disengages the drive to the pump when the machine is started until the tube 10 reaches the jaws 11, 12. During filling each package is supported against members 28, 29 which pivot on the frame 2 and are each connected by springs 142, 143 to the cutters 14, 15. The members 28, 29 may determine the volume of each package where filling is by continuous supply. Intermittent action. With the magnetic clutch engaged, the pulley 54 is driven by means of a sprocket 65 and a reciprocating chain 68 attached at its lower end to a lever 74 pivoted downwards by cam means on the shaft 77. At its opposite end the chain 68 is attached to a spring in a tube 59, the spring raising the chain, when the clutch is disengaged on opening of the contact in the web sensing means 87. A microswitch, Fig. 8 (not shown), arranged in series with the contact in the means 87 is operated momentarily by a cam on the shaft 77 in order to initiate a new winding operation; thereupon the contact in the means 87 closes and resumes control of current to the magnetic clutch. A further microswitch, in parallel with the main switch of the motor circuit, cooperates with a cam disc on the shaft 77 to ensure that the machine stops on completion of an operation. Specifications 588,343, 597,458 and 864,826 are referred to.