Patent GB-1477961-A (GB)
Title: Manufacture of receptacles
IPC: B29C53/00
Filed: 1975-02-20
Abstract: 1477961 Making receptacles; seaming SOC GENERALE POUR L'EMBALLAGE 20 Feb 1975 [20 Feb 1974 21 Feb 1974 22 Feb 1974] 7153/75 Headings B5D B5K and B5A An apparatus for making receptacles having a bottom attached to one end of a tubular body and a cover or rolled rim at the other end of the body comprises a jig 16 which reciprocates vertically between a distributer 17, from which a blank is withdrawn, and jaws 46 which wrap the blank around the jig 16, a device located above the jig for providing the rolled rim or cover or bottom on a first end of the body and for grasping said first end so that upon rotation of the device about a horizontal axis the body is inverted and its second end is presented to a further device which provides the body at said second end with a bottom or rolled rim or cover. The shape of the jig 16 is such that the size of the opening at said first end of the tubular body is less than or equal to that at said second end. As shown in Figs. 2, 2a, the first mentioned device comprises a rim rolling head 55 and the further device comprises a bottom welding head. A plurality of vertically extending receptacle production lines are provided around the periphery of a continuously rotatable turret 10 and the mechanical operation of the components of these lines is controlled by cams mounted on the frame of the apparatus. Blank pick-up and forming.-The jig 16 includes a pivotal suction box (25), Fig. 3 (not shown), and is rotatable so that as the suction box engages the foremost blank in the distributer there is no relative movement between the suction box and blank despite the continuous rotation of the turret 10. A counter electrode (51), Fig. 3 (not shown), inside the jig 16 co-operates with an external electrode 54 to weld together the overlapped edge regions of the blank wrapped around the jig. Rim-rolling and body inversion.-The rimrolling head 55, Fig. 6, comprises a shaped former 67 which is mounted on an axially displaceable and rotational shaft 66, and gripping claws 75 pivotally mounted on a mandrel 65 and controlled by a cam surface 80 on a sleeve 78. In operation the sleeve 78 is moved towards the body with the result that the claws 75 are first cammed closed and former 67 is advanced towards the body edge. When the former 67 is in engagement with the edge it is rotated to roll the rim of the body. After the rim-rolling operation the rim rolling head is rotated through 180 degrees about a horizontal axis YY, while the rolled rim of the body is gripped by the claws 75. Bottom forming and bottom welding head.- The bottoms may be preformed to a concave shape or they may be supplied as flat blanks, delivered from a distributer (97), Fig. 7 (not shown), or cut-out from a strip, and shaped into concave form upon passage through a die orifice 96. A device for pushing the blanks through the orifice 96 and welding the shaped bottoms to the bodies is shown in Fig. 8, and comprises a clamp 107 associated with a welding head consisting of an expandable mandrel 114 and a sliding ring 133 surrounding the mandrel. Welding electrodes, such as 113, are carried by the clamp 107 and the mandrel 114. In operation, as the welding head descends, with the mandrel 114 contracted, the sliding ring imprisons the blank between its lower edge and the surface 106 surrounding the die orifice 90, and the mandrel 114 descends alone through the orifice 96 to shape the blank. Once the mandrel 114 and the shaped bottom are correctly located in the body, the mandrel 114 is expanded to sandwich the bottom and the body between itself and the clamp 107. It is in this condition that the welding is effected. The welding electrodes of the body forming and bottom welding arrangements may weld by high frequency electric current and at least one electrode of each pair is connected to a plate 139 which passes adjacent other fixed plates 140 upon rotation of the turret 10. The plates 140 which are connected to high frequency generator, together with a plate 139 form a condenser in the feed circuit for the electrodes.