초록 ▼

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 loadin

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.

대표청구항 ▼

A method of molding a headpiece on a tubular body, comprising the steps of: seating an open end of a tubular body within a cavity of a female forming member, said cavity being defined by a surface of said female forming member, said surface being configured to define an external surface of a headpie

A method of molding a headpiece on a tubular body, comprising the steps of: seating an open end of a tubular body within a cavity of a female forming member, said cavity being defined by a surface of said female forming member, said surface being configured to define an external surface of a headpiece for said tubular body; disposing a washer, configured to define at least a portion of the internal surface of a headpiece and having a peripherally-expandable portion, within the tubular body adjacent its open end; expanding said peripheral portion of said washer into sealing engagement with the inner surface of the tubular body, and in turn urging the outer surface of the tubular body into sealing engagement with the surface of said forming member, with the tubular body, washer and cavity surface thereby cooperatively defining at least a portion of a mold cavity for forming a headpiece on the body; introducing a flowable synthetic resinous material into said mold cavity; and effecting solidification of said introduced resinous material to form a headpiece on the body.