Patent GB-928447-A (GB)
Title: Improvements in or relating to carton folding machines for converting carton blanks into carton form
Inventor: BAYLEY FREDERICK JAMES
IPC: B31B50/48
Filed: 1960-02-19
Abstract: 928,447. Carton forming machines. PEMBROKE CARTON & PRINTING CO. Ltd. Feb. 13, 1961 [Feb. 19, 1960], No. 6032/60. Class 18. In a carton forming machine of the type comprising a plunger 16 and a die 25, the latter having parts which grip the carton while the plunger 16 is being withdrawn, a section 30 of the die wall can hinge back to provide clearance for the lid of the carton being ejected. Ready cut blanks, Fig. 5, are inserted into the machine along a shoot 34 and the plunger 16, driven down by a pneumatic motor, forces them into the die. As each blank is pressed into the die, flaps 40, 42, 38 contact die shoulders 50, 51, 52 respectively which bend them upwards at 90 degrees in this order. During this operation tongues 42 partially enter slits 43, only their nose parts 47 remaining outside. As the carton is pressed downwards it displaces sprung jaw members 61 into a wall 26 of the die 25 but as soon as the upper front edge of the carton passes jaws 64, the jaw members 61 spring back to grip the carton. Simultaneously a cam and roller mechanism 106 allows the section 30 to move inwards under the action of springs 33, a projection 70 engaging under the rear bottom edge of the carton. The plunger 16, suitably grooved to avoid the jaw members 61, is then withdrawn from the carton, the latter being retained by jaws 64 and by the upper edge of lid 44 engaging under a ledge 71 in the die wall. During the upstroke forked fingers 83 rotate to grip the carton, Fig. 4, and rods 90, operated by further cams 78, force the tongues 42 completely into the slits 43 and thus lock the carton. During the next down stroke of the plunger 16 the fingers 83, the push rods 90 and the wall section 30 are all withdrawn and as the next carton is pressed downwards it displaces the jaw members 61 so that the first carton is freed and pushed out of the bottom of the die. The hinging of wall section 30 allows the lid of the first carton to move back and clear the base of the advancing second carton. In a modification, forming cartons of the type in which extensions of side walls 38 are sandwiched between double walls at 40, the push rods 90 are omitted and the fingers 83, which perform the folding over of the double side walls, are made larger. The provisional specification describes a different method of supporting the blank while the plunger is being withdrawn consisting in a shutter moving beneath the front edge of the carton and ledges in the wall 26, similar to that at 71, which engage the upper edge of the front wall panel 38 of the carton. The blank illustrated in the Provisional Specification has tabs at the edges of the double side walls which engage slits in the bottom of the erected box; it also has side flaps hinged to the lid portion and channels are formed in the sides of the die to accommodate these during the forming process. In a further modification the movement of the fingers 83 may be controlled by cam and follower means as described in Specification 928,446.