Patent ID: 7939008

Claim:
A method of blow-molding a wheel for use on a children's ride-on vehicle, the method comprising: providing a mold, the mold comprising first and second mold portions, wherein the first and second mold portions collectively define a mold cavity configured to mold a wheel having a tread surface, first and second sidewalls and an axis, wherein the first and second mold portions are configured to separate in a direction parallel to the axis of the wheel, wherein at least one of the first and second mold portions comprises: a first tread-molding portion, wherein the first tread-molding portion is configured to mold at least a first region of the tread surface, wherein the first region is disposed between the first sidewall and a part line defined by an interface between the first and second mold portions; at least one second tread-molding portion, wherein the second tread-molding portion is configured to mold a second region of the tread surface, wherein the second region is disposed between the first region and the part line, wherein the second tread-molding portion is configured to move inwardly and outwardly relative to the first tread-molding portion between a molding position and a release position, wherein the molding position comprises: the second tread-molding portion positioned relative to the first tread-molding portion such that a first radial distance from the axis to at least a first region of the first tread-molding portion exceeds a second radial distance from the axis to at least a second region of the second tread-molding portion by a first predetermined threshold; and the release position comprises: the second tread-molding portion positioned relative to the first tread-molding portion such that a third radial distance from the axis to a third region of the second tread-molding portion is at least as great as a distance corresponding to: a fourth radial distance from the axis to a fourth region of the first tread-molding portion that is adjacent the third region of the second tread-molding portion when the second tread-molding portion is in the release position, less a second predetermined threshold; forming a parison of molten material; positioning the parison between the first and second mold portions; closing the first and second mold portions on the parison; injecting a pressurized gas into the parison to blow the parison into a blow-molded wheel having a shape corresponding to the shape of the mold cavity, including regions of the wheel corresponding to the first and second regions of the tread surface; moving each of the at least one second tread-molding portion from the molding position to the release position; and separating the first and second mold portions to release the blow-molded wheel from the mold.