초록 ▼

Apparatus, method and sealing means for liquid urethane reaction mixture injection molding of a composite styled metal and plastic vehicle wheel wherein a metal wheel subassembly serves as a preform between the separable mold parts in the mold apparatus and which is united with the plastic body mold

Apparatus, method and sealing means for liquid urethane reaction mixture injection molding of a composite styled metal and plastic vehicle wheel wherein a metal wheel subassembly serves as a preform between the separable mold parts in the mold apparatus and which is united with the plastic body molding material to form the composite wheel. One of the mold parts has a mold cavity surface operable in mold closed condition to define with the outboard face of the wheel subassembly a mold cavity adapted to provide an ornamental configuration for an outboard face of the plastic body of the composite wheel. A gas permeable and liquid infiltratable mold sealing membrane has a first portion thereof communicating with ambient atmosphere externally of the mold cavity and a second portion thereof communicating with the mold cavity. The membrane is made of fabric material comprising random fibers, calendered into sheet form and selected from the group consisting of polyethylene, polypropylene, Teflon coated polyethylene, and Teflon coated polypropylene fibers. The membrane has a gas permeability ranging between about one to twenty cubic feet of air per minute, and more particularly between about one to four cubic feet of air per minute. The membrane fabric material consists of fibers processed into coherent sheet form having a thickness ranging between about 0.01 inches to about 0.10 inches and having a weight in the order of about 15 ounces per square yard, and is heat seared on at least the side thereof juxtaposed to the mold cavity. The mold sealing membrane is operable to provide flow-through limited venting of gases from the mold cavity to ambient until the membrane seal is clogged by liquid reaction molding material infiltrate therein.

대표청구항 ▼

[ We claim:] [1.] A method of molding a composite styled metal and plastic vehicle wheel of the type having a metal disc and rim subassembly operable as a metal street wheel when a pneumatic tire is mounted on said rim and a decorative plastic body affixed and molded to an outboard surface of the wh

[ We claim:] [1.] A method of molding a composite styled metal and plastic vehicle wheel of the type having a metal disc and rim subassembly operable as a metal street wheel when a pneumatic tire is mounted on said rim and a decorative plastic body affixed and molded to an outboard surface of the wheel to form such composite styled wheel, the disc having a circular row of air venting window openings therethrough, said method utilizing molding apparatus including a lower mold part adapted to disposed to be in sealing engagement against an annular outboard surface of the wheel in the closed condition of the mold apparatus and having a mold cavity surface operable in the mold closed condition to define with such wheel outboard surface, a mold cavity adapted to provide an ornamental wheel mold for forming the decorative plastic body with window openings formed in the plastic body individually registering with the disc window openings, and an upper mold part comprising a clamp operable for seating in the mold closed condition against an inboard face of the wheel for urging the same into sealing engagement with the lower mold part, the clamp carrying a flexible annular seal shaped for engagement with the inboard face of the disc in overlying relation with the disc windows to thereby define a flash forming area along a mold parting line where the annular seal and disc inboard face window openings meet, the mold parts being axially separable from one another to open the mold apparatus and clear the clamp along the parting line from the wheel and the wheel from the lower mold part, said method comprising the steps of:(1) providing a gas permeable and liquid infiltratable flexible and compressible membrane means made of thin generally flat flexible and compressible porous material having opposed major surfaces defining the thickness dimension of the material,(2) when the wheel and the upper mold part clamp seal are separated from one another, placing said membrane means with one of its major surfaces loosely against the disc inboard surface such that at least a first portion of the membrane means will remain directly exposed to ambient atmosphere exteriorly of the disc inboard surface when the clamp seal and wheel are closed together to define the parting line so that after such closure the membrane means remains in gas venting communication with ambient atmosphere externally of the mold cavity via the first portion of the membrane means, and such that a second portion of the membrane means remains directly exposed to and forms a mold cavity surface within the marginal edge of each associated one of the disc window openings when the clamp seal and wheel are closed together and thus remains interiorly exposed in gas venting communication with the mold cavity through such disc window openings,(3) closing said lower and upper mold parts against the metal wheel to thereby cause the flexible clamp seal to yieldably squeeze the membrane means by direct engagement of its major surfaces with and between the respectively adjacent clamp seal and wheel to thereby conform, in response to such closure, the membrane means with the disc inboard surface to thereby define a parting line interface between the membrane means one major surface and the disc inboard surface at and within the edge of each disc window opening,(4) filling the mold cavity with liquid urethane reaction mixture and allowing the same to infiltrate the membrane means via the second portion interiorly exposed surface in the associated disc window opening as gas is being vented from the mold cavity to ambient along the parting line via flow in the membrane means first portion between its major surfaces thence out to ambient via the exteriorly exposed surface of the membrane means first portion,(5) causing the urethane reaction to solidify by curing in the mold cavity while simultaneously removably attaching the membrane means to the disc by adhesion between the cured urethane reaction mixture and the membrane means second portion,(6) opening the mold apparatus after solidification of the reaction mixture to expose the inboard surface of the wheel with the membrane means so adhesively attached thereto, and(7) removing said membrane means from the wheel by peeling the adhered one major surface of the membrane means surface off of the disc inboard surface and off of the cured urethane mixture along their parting line interface with the membrane means one major surface.