HEAT SEALING DEVICE FOR HEAT SEALING SEAMS ON THERMOPLASTIC OVERWRAPS ON PACKETS

摘要

1515145 Seaming non-metallic sheet material GD SpA 4 July 1975 [10 July 1974] 28380/75 Heading B5K A heat sealing device, positioned adjacent a sealing station of an intermittently-rotatable wrapping wheel 1, comprises a reciprocable member 7 having a narrow heat sealing face, a heat source 10 adjacent the sealing face, and a probe 11 for measuring the temperature prevailing at the sealing face and responding thereto to control the heat sealing time of the device. The wrapping wheel 1 on which a packet P of cigarettes is wrapped in an outer thermoplastic sheet S is intermittently rotatable through 60 degree angles around a shaft 2 and comprises six radial compartments 3. At a station I, a packet P together with a sheet S is inserted into the compartment 3 thereat so that two ends of the sheet S protrude, these ends then being folded on to the external side of the packet P by a movable member 4 and an edge of a fixed guide 5. The folded ends are heat sealed at stations II, III through breaks in the guide 5 by members 7, 71 mounted on supports 8, 8SP1/SP oscillatable about shafts 9, 91. An electrical resistor 10, 10SP1/SP and a temperature measuring probe 11, 11SP1/SP are inserted in the body of each member 7, 7SP1/SP. The parts of the wrap adjacent the sealing area are protected from irradiated heat by thermally insulating plates 12, 12SP1/SP, fixed to the guide 5. Each packet P is ejected by a pusher 6 into a channel 13, Fig. 2, in which the packet ends are sealed by reciprocable members 14, 14SP1/SP mounted on supports 15, 15SP1/SP and provided with heat sources 10, 10SP1/SP and temperature measuring probes 11, 11SP1/SP. The members 14, 141 act on the packet ends through slits in thermally insulating plates 16, 16SP1/SP.