Abstract: A polymeric radiator having front and back radiator halves, that cooperate to define a primary coolant passage and a series of secondary coolant passages. The primary coolant passage includes integral internal baffles extending inwardly from the radiator halves. The internal baffles define passageways to allow coolant to flow through the radiator. Preferably, the passageways do not intersect the mating edges of the front and back radiator halves to enhance the structural integrity of the radiator.

Abstract: An electroplated, polymeric fuel tank fabricated of inner and outer shells. The outer shell is an assembly of outer shell halves joined together along peripheral flanges. A layer of copper, a layer of nickel, and a layer of chrome are successively electroplated to either or both of the interior and exterior surfaces of the outer shell halves to prevent permeation of fuel through the shell.

Abstract: A polymeric muffler including two halves each with baffle walls and gas flow openings integrally molded therein. The gas flow openings do not intersect with the mating edges of the baffle walls. The muffler halves are joined along the mating edges of the baffle walls and the outer walls of the two muffler halves. In a preferred embodiment, the muffler includes a filter detachably mounted on the muffler for converting exhaust gases into less toxic products. The gas flow openings are positioned to force all exhaust gas to pass through the filter.

Abstract: An injection molding apparatus is disclosed for forming articles with internal undercuts by the use of lifter heads with transversely extending protrusions. The lifter heads are received in recesses in the mold projections which form the interior of the molded article. The transverse protrusions of the lifter heads extend into the voids surrounding the projections to form the undercuts. The lifter heads are extended outwardly from the projections to remove the article from the mold. Ejector pins move the molded article outwardly from the lifter heads. The lifter head protrusions have inward ramping surfaces which facilitate the removal of the molded article. A lifter head may include two, angularly offset protrusions which form two undercuts near the corner between intersecting internal walls of the molded article. The protrusions have beveled release surfaces which allow the molded article to shift transversely off the lifter heads.

Abstract: A fuel tank is disclosed having an inner shell, an outer shell enveloping the inner shell, and a fuel absorbent material filling the space between the inner shell and the outer shell. The fuel absorbent material is preferably a molded granular material. The inner shell is an assembly of injection molded plastic halves joined together along peripheral flanges, each inner shell half being integrally formed with internal walls. The internal walls are formed with undercut openings. The outer shell is an assembly of outer shell halves joined together along peripheral flanges. Also disclosed is an injection molding apparatus adapted to manufacture the inner shell halves with undercut openings in the internal walls.

Abstract: A modular building panel wherein building panels are formed of two polymeric panel halves each having ribs with passageways formed integrally therein. The panel halves are joined together along the mating edges of the mating ribs. The passageways do not intersect with the mating edges of the panel halves. The passageways facilitate the installation of wiring and insulation into completed panels.

Abstract: An injection molding apparatus is disclosed for forming articles with internal undercuts by the use of lifter heads with transversely extending protrusions. The lifter heads are received in recesses in the mold projections which form the interior of the molded article. The transverse protrusions of the lifter heads extend into the voids surrounding the projections to form the undercuts. The lifter heads are extended outwardly from the projections to remove the article from the mold. Ejector pins move the molded article outwardly from the lifter heads. The lifter head protrusions have inward ramping surfaces which facilitate the removal of the molded article. A lifter head may include two, angularly offset protrusions which form two undercuts near the corner between intersecting internal walls of the molded article. The protrusions have beveled release surfaces which allow the molded article to shift transversely off the lifter heads.