Patent GB-1490301-A (GB)
Title: Manufacturing containers by folding blanks
IPC: B65D5/20
Filed: 1975-04-03
Abstract: 1490301 Erecting tray blanks MACHIDA SHIGYO CO Ltd 3 April 1975 [16 April 1974 9 Jan 1975 22 Jan 1975] 13689/75 Heading B5D [Also in Division B8] A device for erecting plastics coated tray blanks, Fig. 11, having a bottom panel 151, side wall panels 152, 153 and corner panels 154, comprises a stationary die 42 having seats 52 or (52a), Fig. 18 (not shown), for supporting a blank at its corners above the die opening, a vertically movable plunger 44, and means, such as weighted rods 58 or pawls (116) Fig. 17 (not shown), for pressing one side wall panel of each of a plurality of pairs of adjacent side wall panels against the upper surface of the die 42. In operation, as the plunger 44 descends towards and into the die 42, the weighted rods 58 or pawls (116) press and retain the associated side wall panels 153 flat against the upper surface of the die 42 while the side wall panels 152 that are not engaged by the rods 58 or pawls (116), are folded up relative to the bottom panel 151 and said die upper surface. Simultaneously the corner panels 154 are folded inwards by engagement with the seats 52 or (52a) to lie against said retained side wall panels 153. An upwardly spring-urged blank end tray support plate 61 which is displaceable by the plunger 44, is provided in the die cavity. The blank may include a peripheral flange forming portion 155 which may constitute a horizontal flange (163), Fig. 13 (not shown), an angular flange or a downwardly curved flange (163a), Fig. 21 (not shown), in the finished tray. To form the horizontal flange (163), a holding plate 64 which resiliently mounts the plunger 44, and pivotal presses 57 which are movable therewith, cooperate with a step 50 on the inside of the die. To form an angular flange or the downwardly curved flange (163a), an appropriately shaped protrusion (88), Fig. 20 (not shown), which is provided on the upper surface of the die around the opening, co-operates with a holding plate (64a), Fig. 20 (not shown), which is recessed complementarily to the protrusion, and pivotal presses (57a), Fig. 20 (not shown). The above blank erecting device is embodied in an apparatus, Figs. 1A-1C (not shown), which includes a blank magazine (1) for supplying successive blanks to a conveyer (2, 23) which moves the blanks into and out of a heater (C) for heating regions of the plastics coated blank to be secured to one another. The heater (C) comprises an air blower (28), pipes (26) for ducting the air from the blower to the blank regions to be heated, and heating elements (27) in the pipes (26). After leaving the heater the blank is pushed into position between the die and plunger. The erected tray is automatically removed from the die support plate 61 and placed in conveying box (81) in which it is moved to a pressing station (H). At this station a vertically movable heating plate (94) presses against the container flange through the intermediary of a continuous and movable polytetrafluoroethylene cloth material belt (99). The pressed tray is then conveyed in the box (81) to a discharge station I whereat one of a plurality of arms (113), mounted on a rotatable shaft (111), enters the bottom of the box (81) and pushes the tray therefrom.