Patent GB-819355-A (GB)
Title: Dispensing cartons and like containers having strong end closures and method of making them
IPC: B31B17/00
Filed: 1955-11-25
Abstract: 819,355. Making boxes. BERGSTEIN, R. M., and BERGSTEIN, F. D. Nov. 25, 1955 [Dec. 20, 1954], No. 33916/55. Class 18. A one-piece paperboard container with tubular body walls 1-4 has an end closure comprising three outwardly extending flanges 13, 14, 15, articulated to the ends of the walls 2, 3, 4, and a full width flap 10 articulated to the end of wall 1 with a second flap 18 articulated to a side of the flap 10, the flaps 10, 18, being secured together face to face and adhesively secured to the flanges 13, 14, 15. The blank shown in Fig. 1, is formed into a tube by a container gluing machine and then inverted over a mandrel whereupon the bottom flaps 6-9 are infolded and sealed by pressure. The container is then placed upright in a cage or other conveyer and the flaps 10, 18 are jointly folded outwards to be supported by a horizontal plate at the same time separating the flap 18 from the flange 13 along the line for severance 20. Adhesive is applied to one of the flaps 10, 18 avoiding the region of the liftable flap 11, the flaps are elevated by a sweep and the flap 18 is folded onto the flap 10 by a folding bar, after which the flaps pass between pressure rollers to assure a good bond. An internal pressure member 32, Fig. 6, then enters the container and external pressure members 33, 34 co-act with ledges 35, 36 to bend inwardly the upper portions 2a, 4a, of the walls 2, 4, at the same time bending out the flanges 13, 15. The portion 3a and flange 14 are concurrently folded by similar means. A narrow peripheral strip of adhesive is applied round the under surface of the flap 18 and the flaps are folded down into adhesive contact with the flanges 13, 14, 15 which are then supported by fingers while a pressure plate applies sealing pressure. Cut out triangles 16, 17 will produce mitred comers if desired. The container is proofed internally by introducing a molten sealing substance and after closing the flap 11 an end casting 41 bonded to the walls and end is formed including a severable plug portion 42, Fig. 13. The liftable flap 11 is locked in closed position by crimping its extending portions 11a 11b over the edges of the flanges 14, 15. In a modification, the flanges may be folded out to extend outside the contour of the walls and larger flaps provided to cover the increased area. A narrow flange may also be provided on the fourth wall with the flush or extended end closure. The fold lines in the blank defining the flanges 13, 14, 15 and end portions 2a, 3a, 4a need not be preformed but may be marked by small vertical cuts only. In this case, when the container is placed over a mandrel 70, Fig. 20, for the bottom to be sealed under pressure plate 71, members 75, 76, 77 press the upper ends into recesses in the mandrel to deflect the walls inwardly and fold narrow flanges outwardly. The resilience of the paperboard allows the container to be removed and the upright container is then acted on by further members which move in to support the flanges while a pressure plate applied to the folded down flaps applies sealing pressure.