ES303162A1 - Carton end closing mechanism - Google Patents

Abstract

A carton closing machine, has a turntable 16, Fig. 1 (not shown), with four carton receptacles 17 movable through a carton and liner closing station where closing mechanism 19 is pneumatically or hydraulically operated, the carton being of the type having at each end a rear closing flap joined at its side edges to gusseted side flaps. The machine may be used to close the base of an unfilled carton, the carton being inverted, or to close tbe top of a filled carton. The turntable 16 may be turned by hand or by an electric motor through Geneva mechanism. As the carton is moved towards the closing station a stationary bar folds the front closing flap outwards. At the closing station a plunger on a fixed table spaced below the turntable 16 locks in a slot in a ring carried under the turntable and at the same time actuates a start air valve, Figs. 10 and 12-13 (not shown). A cam block is thereby moved to operate the air valves governing the action of the mechanism 19. The carton is then in the position shown in Fig. 4, the unsealed liner projecting at 26 above the top edge of a side flap 23 which extends upwards from a side wall panel 29 and is united at its rear edge to the rear flap 22. Each side flap 23 has fold lines forming a triangular gusset 27 the forward edge 30 of which forms the rear edge of a triangular cut-out. A crease 24 enables a flap 25 in each member 23 to be folded back. Since the flaps 25 are stuck to the liner, the liner is also folded. Lines 231 and 24 are broken inwards as a plate 32 is advanced in co-operation with side plates 33 which are moved to the position shown in interrupted lines at 331. When levers 38 on the plates 33 strike cam blocks 39, the plates 33 move inwards, thereby breaking the lines 231 and 24. The plate 32 both prevents the front edges of the flaps 25 from moving inwards and, at its position 3211, begins the folding of the liner. A hinged member 21 is caused to press down the rear flap 22, while a heat-sealing jaw on the member 21 co-operates with a pivoted heat-sealing jaw 50 to seal the projecting liner. Alternatively, the liner is sealed by rollers as the carton leaves the closing station. A stationary bar turns over the front flap and inserts a tongue on it into a slot in the rear flap. The front and rear flaps may be glued. The carton may be unlined.