Patent GB-1460692-A (GB)
Title: Apparatus for the sealing of packaging containers
IPC: B65B51/10
Filed: 1975-02-17
Abstract: 1460692 Seaming non-metallic sheet material ROBERT BOSCH GmbH 17 Feb 1975 [18 Feb 1974] 6665/75 Heading B5K [Also in Division B8] Apparatus for welding a cover 10 onto an outstanding flange of a filled packaging container 11 comprises first and second welding units I, II, respectively, mounted on an endless conveyer 12 angularly spaced from one another, and a device 60 arranged in the common path of the units I, II for transferring a container, after the application of a weld seam by the unit I, out of the operative region of the unit I and into the operative region of the unit II. The cover 10 and the container 11 may be formed of a plastics-aluminium laminate. The conveyer 12 comprises a continuously rotatable drum. The units I, II comprise, respectively, heated upper heads 13, 14 and downwardly movable dies 15, 16 with frame-like ribs 17, 18 and 19, 20. Recesses 21, 22 for receiving a container 11 are provided in the dies 15, 16 and have base plates 23, 24 each connected to a ring 26, 27 through displaceable supports 25. The drum 12 comprises a plate 30 connected to a table 31 by a tube 33, a plate 32 connected to the table 31 by supports 34, is rotatably mounted on a column 36 and is driven by a gear 37 engaging a ring 38 on the table 31. The dies 15, 16 are supported on rods 40, 41 vertically displaceable in the table 31 and the plate 32 and which have blocks 43, 44 fixed thereto carrying rollers 45, 46 supported by a fixed pot-cam 47. Individual containers 11 are fed by a rotating arm 55 with the flange resting on guides 52, 53 and each is deposited on the plate 23 on the unit I. The cover 10 may be supplied resting on the container 11 or may be brought into the path of the units I, II and sucked against the underside of the head 13. As the drum 12 rotates, the die 15 is raised and presses the container flange against the cover 10 on the head 13, position 3, Fig. 3, and, after a predetermined period in which heat and pressure is applied between the head 13 and the die 15, the die 15 is lowered and the container 11 comes to rest on the plate 23. In this position, the upper side of the rib 18 is approximately 10- 20 mm. beyond the upper side of the plate 23, position 5, Fig. 3. The transfer device 60 comprises a plate 61 having a slot 62 defined by arcuate guides 63, 64 with rising portions 65, 66 and descending portions 67, 68. As the container is introduced into the slot 62, it is pushed by the rear of the rib 18 and its flange runs on the portions 65, 66 and onto the central horizontal position of the guides 63, 64. The die 15 is lowered so that the rib 18 comes out of contact with the container which remains hanging in the slot 62. As the unit II approaches the device 60 the die 16 is in its lowermost position with the upper side of the rib 20 lying beneath the base of the container 11. As the drum 12 rotates, a projecting finger 58 at the rear of the plate 24 strikes the container and pushes it along the slot 62 so that it comes to rest on the plate 24. As the unit II passes the loading region for the unit I, the plate 24 is in its lower position so that the container 11 is conveyed freely beneath the guides 52, 53. As the drum 12 rotates, the die 16 is raised by the cam 47 to form a second weld covering the first and is then lowered. The plate 24 is raised above the rib 20, position 4, Fig. 3, and the twice-welded container is removed by a rail 70 so positioned that a container supported by the unit I passes freely therebeneath. Preferably, the first weld seam is wider than the second, e.g. formed by the ribs 17, 18 being 3 mm. thick and the ribs 19, 20 being 2 mm. thick. Alternatively, the seams may be congruent, partially overlap and may be parallel but spaced apart.  In another embodiment (not shown), the apparatus is provided with a plurality of pairs of units I, II which are arranged alternately on the drum.