Abstract: The invention relates to blow molding of an article having an inwardly projecting hollow boss with a closed end. A portion of a molten parison conforms to the shape of a fixed pin projecting from the face of a mold part to thereby form the hollow boss. The invention includes an apparatus comprising a reciprocable sleeve slidably received within the mold part over the pin. It has been found that by blow molding the parison with the sleeve initially extended with its end substantially flush with the end of the pin, followed by retracting the sleeve to a retracted position after a predetermined delay time, a boss with a thicker end results. Consequently, the boss end has greater structural integrity, and thus minimizes or eliminates the possibility of penetration and/or cracking of the boss end when a screw is threadedly received in the hollow boss.

Abstract: The invention relates to blow molding of an article having an inwardly projecting hollow boss with a closed end. A portion of a molten parison conforms to the shape of a fixed pin projecting from the face of a mold part to thereby form the hollow boss. An apparatus disclosed herein includes a reciprocable sleeve slidably received within the mold part over the pin. It has been found that by blow molding the parison with the sleeve initially extended with its end substantially flush with the end of the pin, followed by retracting the sleeve to a retracted position after a predetermined delay time, a boss with a thicker end results. Consequently, the boss end has greater structural integrity, and thus minimizes or eliminates the possibility of penetration and/or cracking of the boss end when a screw is threadedly received in the hollow boss.

Abstract: The invention relates to blow molding of an article having an inwardly projecting hollow boss with a closed end. A portion of a molten parison conforms to the shape of a fixed pin projecting from the face of a mold part to thereby form the hollow boss. The invention includes an apparatus comprising a reciprocable sleeve slidably received within the mold part over the pin. It has been found that by blow molding the parison with the sleeve initially extended with its end substantially flush with the end of the pin, followed by retracting the sleeve to a retracted position after a predetermined delay time, a boss with a thicker end results. Consequently, the boss end has greater structural integrity, and thus minimizes or eliminates the possibility of penetration and/or cracking of the boss end when a screw is threadedly received in the hollow boss.

Abstract: A molding apparatus and method are adapted to mold an article having a hollow blow molded portion and a substantially solid compression molded portion. Defined within a mold is at least a first cavity portion and a second cavity portion. A parison is positioned within the mold and blow gas is injected into the interior of the parison to inflate the parison within each of the cavity portions. A compression member is then moved from a retracted position within a recess in the mold to an extended position outside of such recess. The compression member presses a first portion of the parison against the mold interior surface which defines the first cavity portion so as to compression mold a first portion of the parison. Inflation of a second portion of the parison in the second cavity portion accomplishes blow molding of such second parison portion.

Abstract: A molding apparatus is provided which is operated to mold an article having a hollow blow molded portion and a substantially solid compression molded portion. A mold is provided which has defined therein at least a first cavity portion and a second cavity portion. A parison is positioned within the mold and blow gas is injected into the interior of the parison to inflate the parison within each of the cavity portions. A compression member is then moved from a retracted position within a recess in the mold to an extended position outside of such recess. The compression member presses a first portion of the parison against the mold interior surface which defines the first cavity portion so as to compression mold a first portion of the parison. Inflation of a second portion of the parison in the second cavity portion accomplishes blow molding of such second parison portion.