Patent GB-1322558-A (GB)
Title: Packaging apparatus
IPC: B29C65/00
Filed: 1970-10-08
Abstract: 1322558 Seaming non-metallic sheet material AMF Inc 8 Oct 1970 [25 Nov 1969] 48014/70 Heading B5K [Also in Division B8] Thermoplastic sheets are sealed together by advancing them through supporting means and applying heat to the sheets to effect sealing as they are passed through the supporting means, tension being applied to the sheets prior to the application of heat thereto.  In a packaging machine, articles to be packaged are advanced along a conveyer 10, Fig. 1, to a gate 12 which opens upon the sensing by a device 14 of a predetermined article or group of articles. The articles are fed on to a second conveyer 18 and pass a second sensing device 20 as they move on to a conveyer 24. Sheets 27, 31 of thermoplastic film are withdrawn from reels 28, 32 by feed rollers 26, 30 and are brought together to surround an incoming article. A longitudinal perforation is formed in the film 27 by a wheel and anvil 26. The longitudinal side edges of the films are sealed by a device comprising two pairs of rollers 94, 108, 140, 142 mounted at each side of the machine. The packages are transversely sealed and severed by a device 38 and are removed by a conveyer 40. The forward upper roller 94, Fig. 5, of each side sealing device is formed on a collar 90 rotatably mounted on a shaft 80 and is driven from the main drive of the machine by a chain passing around a sprocket 96 thereon. A connecting arm 104 is pivotally mounted on the shaft 80 and has a shaft 106, Fig. 4, mounted on the other end thereof. The roller 108, which may be ridged, as shown, is rotatable about the shaft 106 by a chain 115 passing around a sprocket 112 thereon and a sprocket 98 on the shaft 80. The sprocket 98 is smaller than the sprocket 112 so that the roller 108 is driven faster than the roller 94 to preclude rippling of the film between the two sets of rollers. The roller 108 is engageable and disengagable with the film by actuating an air cylinder 120, Fig. 6, to pivot the arm 104 about the shaft 80, Fig. 5. Slots 152, 154 are provided in an upper guide 144 to allow the rollers 94, 108 access to the film. The roller 108 is made of aluminium covered with polytetrafluoroethylene around the rim thereof and is heated by an electrical element 158, Fig. 4, connected through a lead 162 and a plug 163 to a power source. Insulating collars 166 are mounted on the shaft 106. The lower rollers 140, 142 are rotatably mounted on shafts 136, 138, Fig. 1, mounted on a bar vonnected to a platform 130. The rollets 140, 142 are engagable and disengagable with the film passing over the platform 130 by an air cylinder 122 which pivots the bar supporting the shafts 136, 138, slots  152, 154 being provided in the platform 130 to permit the rollers 140, 142 to contact the film. The roller 142 may be made of rubber. During sealing, the pressure of the driven rollers 94, 108 is sufficient to rotate the rollers 140, 142. The rollers 108, 142 are mounted at an angle to the rest of the side sealing parts due to a bend 156, Fig. 5, in the arm 104 and an annular surface in the bar supporting the shafts 136, 138. However, the rollers 94, 140 are mouned at a diverging angle relative to the direction of movement of the conveyer 24, Fig. 1, so as to laterally tension the film.