Method of molding a headpiece on a tubular body

Abstract

Method in which an expandable internal shoulder forming member assembly to be used for forming a headpiece onto a preformed thin-walled plastic or laminate tube or bag provides a internal shoulder forming member upon which the loose fitting preformed thin-walled tube can be loaded. After tube loading, the internal shoulder forming member is inserted into a female forming member. Toward the end of the internal shoulder forming member's insertion stroke, a internal neck forming member which is mounted for axially movement within the head end of the internal shoulder forming member contacts the female forming member and then partially retracts into the head end of the internal shoulder forming member as the internal shoulder forming member continues to advance to the end of its insertion stroke. A conically-shaped washer mounted on the bottom end of the internal neck forming member is peripherally expanded by the continued advancement of the internal shoulder forming member after the top end of the internal neck forming member has contacted the female forming member. As the internal shoulder forming member reaches the end of its forward stroke, which will be the closed position of the internal shoulder forming member relative to the female forming member, the expanding periphery of the washer makes contact with the preformed tube body at a location below the portion of the tube body which extends beyond the internal shoulder forming member to effect a tight sealing fit between the internal shoulder forming member, the tube body and the female forming member to define a mold cavity in which the headpiece to the tube body may be formed.

Dependencies are inferred from the claim text.