GB1336516A - Apparatus for forming containers closed with labelled covers - Google Patents

Abstract

1336516 Apparatus for forming containers closed with labelled covers PLASTIQUE MECANIQUE ET ELECTRONIQUE SA 5 July 1972 [23 July 1971] 31489/72 Heading B8C An apparatus for forming containers closed with a cover carrying a label comprises a first sheet of thermoplastic material, on aluminium 1, which is unwound from a reel 3, heated at station CH, vacuum-formed in a mould 5 at station PF to produce a series of containers la at constant pitch d which containers are filled with a quantity of product at station C and which have lids applied at a welding station PS from a second strip 2, the latter being selected from the same range of materials from which the strip 1 may be made and being provided with a series of printed-on labels spaced at a pitch P which is slightly less than the pitch D. Finally the apparatus provides a cutting-and-ejection station PD. The containers and the covering strip 2 are advanced together intermittently at one, or more, times the pitch d by a piston-and-cylinder operated reciprocating clamping mechanism 27-29. The apparatus is characterized in that, at a position ahead of the welding station PS, the strip 2 is clamped at longitudinally-spaced locations by bars 17, Fig. 2 as it is guided through a stretching station PE and is permanently stretched between the bars 17, 17 by a punch 16 which interacts with a die 11a on a main support 11, the amount of stretching being proportional to the difference between the pitches d and D as sensed by a sensor 14, or 14<1>, which reads reference points on the strip 2. The bars 17, provided with linings 17a, are carried by a cross bar 15 connected to the piston-rod of a piston-andcylinder unit 25, 34 the stroke of which can be adjusted by a nut 35 and lock nut 36. The sensor 14, which as shown is a photo-electric device, is adjustable, with respect to the longitudinal direction of the strips, by a screw-andnut mechanism 12, 12a. The strip 2 is guided into and out of, the stretching mechanism P.E. between guide plates such as 14b, and passes over rollers 4g, 4f, 4e the roller 4g being a tensioning roller. The references 2a on the strip 2 are either printed, perforated, or magnetic. Since 5% elongation of the strip 2 can be obtained without a risk of rupture the stretching operation may be necessary only, at two, or three, steps of the machine.