GB1246110A - Wrapping machine - Google Patents

Abstract

1,246,110. Packaging. CARL DROHMANN G.m.b.H. 12 Dec., 1968 [28 Dec., 1967], No. 59102/68. Heading B8C. A machine for wrapping individual objects or assemblies B comprising a plurality of individual objects, using a wrapping material which is heatsealable or includes a coating of a heat sealable material by a sequence of operations in which the wrapping material is first arranged around the object or assembly to be wrapped, the material is sealed along a seam or seams in such a manner as to form a tube-like sleeve around the object or assembly, and the end portions of the sleeve which project beyond the object or assembly are sealed to close the ends of the sleeve, as characterized by seal-forming devices 9, 10, provided with sealing jaws 7, 8 and arranged to engage the projecting end portions U of the sleeve of wrapping material formed around the object or assembly, to form heat sealed seams in these portions thereby closing the ends of the sleeve, and to sever the sleeve adjacent the seams thereby to trim off surplus parts of the sleeve, there being associated with the seal forming devices means for holding the said surplus parts on disengagement of the jaws from the sleeve and for discharging these parts. In the construction shown the individual object or assembly B is pushed with the wrapping material, by means of a pneumatically operated pusher 1, through a folding device (not shown) which folds the wrapper into the sleeve S around the object or assembly B and a longitudinal seams is produced by sealing jaws 2 in a known way. The block B with its sleeve S is then passed to the operating position in which it is disposed between the two seal-forming devices. The jaw 7 of each such device is the lower jaw and the jaw 8 is the upper jaw; each upper jaw is equipped with a hot wire 11 by means of which the flatmost layers of the projecting portions U are both welded together in closing position and the surplus parts are separated. To form the end closures the jaws 7 and 8 of each device are moved towards each other (by means not shown). Each of the means for holding the surplus parts consists of vertically movable pins mounted on the jaw 8 and which are biased downwardly by springs 16 and fingers 18 mounted on the jaw 7 by means of a shaft 17, each finger being in the form of a double armed lever the finger forming arm of which is disposed in a pocket 25 in the upper side. of the jaw 7 and the other arm of which carries a roller 20 which runs on a fixed guide rail 23. When the jaws 7, 8 have moved the projecting portions U to form the end closures the parts N which will become surplus are pressed by the pins 15 against the jaw 7 to hold the parts N in position until the jaws are moved apart after the hot wires have welded and severed the parts N; during the separating of the jaws 7 and 8 the pins 15 are lifted by the jaws 8 and the downward movement of the jaws 7 causes the rollers 20 to engage the guide rails 23 so that the fingers pivot to move the finger forming arms out of the pockets 25 and thus move the portions N so that they are discharged into receptacles 24. When the object or assembly to be wrapped is large the formation of the end closures from the projecting portions U is assisted by means of a pair of separated fingers 4 and 5 of known form associated with each seal forming device. The fingers 4 and 5 engage the projecting portions at the sides and spread the sides apart simultaneously with the movement of the jaws 7 and 8 together. The fingers 4 and 5 are operated by pneumatic cylinder units 6. When the fingers 4 and 5 are used the downward movement of the pins 15 is prevented, until the fingers 4 and 5 have completed their spreading movement, by means of angle bars 27 which engage the pins 15 and release them at a predetermined time. The machine can be provided with an air nozzle 13 disposed between the two seals forming devices which directs an air flow against the upper side of the sleeve; this produces a suction which holds the top of the sleeve substantially horizontal to allow the unobstructed insertion of the fingers 4 and 5.