Method and device for forming, closing and reciprocally fastening the flaps of a box such as an American cardboard box

In a method for forming, closing and reciprocally fastening the flaps of a box selected from a group of an American cardboard box, an American halfbox, a Dutch-box, and an equivalent box, the box comprising a pair of internal flaps situated on a side of an internal volume of the box and a pair of external flaps which cover the internal flaps, the method including the steps of bringing the internal flaps into their final position, depositing glue on fastening zones of the internal flaps, bringing the external flaps at least substantially into their final position with the glue fastening zones being in reciprocal contact and with facing free edges of the external flaps being spaced apart by a slot-shaped passage extending therebetween, then temporarily exerting a force on the two pairs of flaps, which force is appropriate to hold the flaps together and to maintain the fixed contact between the reciprocal fastening zones for a period required for an appropriate setting of the glue, the improvements comprising the step of temporarily exerting a force on the two pairs of flaps locking the flaps in their final position in order to prevent them from tending to return toward their initial position and being accomplished by applying a suction from the outside of the box through said slot-shaped passage limited by the two facing free edges of the pair of external flaps, said suction causing the internal flaps to be applied and held against the exterior flaps.