Method and apparatus for molding a composite modular tile with edge interlocks

An injection molding apparatus for making a modular interlocking composite plastic tile of a substrate with preformed planar plastic lamina laminated thereto, comprising:

• first and second co-actable mold platens having substantially planar faces mounted in substantially parallel and opposed relationship,
• means for fixedly mounting the first platen,
• drive means for driving the second platen toward and away from said first fixed platen,
• first and second open-ended mold cavities recessed in the faces of said first and second platens respectively for molding bottom and top portions of the tile substrate, respectively,
• said cavities having open ends aligned substantially opposite one another for forming an enclosed mold when the face of said second platen is driven into abutting relationship with the face of said first platen by the said drive means,
• each of said cavities having a substantially planar base substantially parallel to and inwardly of the planes of a corresponding one of the platen faces and first, second, third, and fourth substantially rectangular sidewalls adjoining corresponding first and second one of the cavity bases and extending substantially perpendicularly therefrom toward the plane of a corresponding platen,
• said first and second sidewalls disposed at substantially right angles with respect to each other and intersecting to form a first interior corner region in each of their respective cavities, and said third and fourth sidewalls disposed at substantially right angles with respect to each other and intersecting to form a second transversely opposite interior corner region in each of their respective cavities,
• a pair of first elongated interlock element molding strips each formed in the platen face of said first platen adjacent the first and second sidewalls, respectively, of said first platen, and positioned opposite said second cavity laterally inwardly of the first and second sidewalls thereof, respectively, for molding a first pair of substantially right-angled substrate edges and contiguous portions of the substrate in the first corner region of the first cavity,
• a pair of second elongated interlock element molding strips each formed in the platen face of said second platen laterally outwardly of said third and fourth sidewalls respectively, of said second platen and projecting towards the plane of said first platen face for molding therebetween a second pair of substantially right-angled substrate edges and contiguous portions of the substrate laterally outwardly of said second corner region of said second cavity,
• the first and second pairs of molding element strips having respective substantially identical, inverted patterns of edge interlock elements thereon,
• the corner regions of said second cavity being spaced to receive and position plastic lamina in said second cavity in an orientation substantially parallel to the plane of said second mold platen, and conduit means coupled to said first platen and communicating with said first cavity for feeding molten substrate plastic for the tile substrate into said closed mold, whereby the substrate is molded and the lamina adhered thereto during substrate molding.