US 7,621,543 B2Granted

Blow-molded wheels having undercut treads, methods for producing the same, and children's ride-on vehicles including the same

AssigneeMattel, Inc.

InventorsAlbert L. Arendt, James R. Carducci, Christopher F. Lucas

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Abstract

Improved blow-molded wheels, methods for producing the same, and children's ride-on vehicles including the same are disclosed. The blow-molded wheels may include a blow-molded body that has a tread surface, first and second sidewalls and an axis. The body may be configured to rotate about the axis. The tread surface may extend circumferentially around the body and may extend between the first and second sidewalls. A first region of the tread surface may be disposed between the first sidewall and a part line of the blow-molded body. A second region of the tread surface may be disposed between the first region and the part line. A first radial distance from the axis to the first region may exceed a second radial distance from the axis to the second region by at least a first predetermined threshold.

Claims20

Dependent claims

A children's ride-on vehicle, comprising:

a body having at least one seat sized for a child;
a plurality of wheels rotatably coupled to the body, wherein the plurality of wheels includes at least one driven wheel and at least one steerable wheel, wherein at least one of the plurality of wheels is a blow-molded wheel that comprises:
a blow-molded body having a diameter, a tread surface, first and second sidewalls, a part line, and an axis, wherein the body is configured to rotate about the axis, wherein the tread surface and the part line extend circumferentially around the body and between the first and second sidewalls;
a first region of the tread surface, wherein the first region is disposed between the first sidewall and the part line of the blow-molded body;
and
a second region of the tread surface, wherein the second region is disposed between the first region and the part line, wherein a first radial distance from the axis to the first region exceeds a second radial distance from the axis to the second region by at least a first predetermined threshold, wherein the first predetermined threshold is greater than the larger of ⅛ inch and 0.1% of the diameter;
a steering assembly comprising a steering mechanism adapted to receive steering inputs from a child sitting on the at least one seat, and a steering linkage adapted to convey the steering inputs to the at least one steerable wheel;
and
a drive assembly adapted to selectively drive the rotation of the at least one driven wheel.

6 more elements

A children's ride-on vehicle, comprising:

a body having at least one seat sized for a child;
a plurality of wheels rotatably coupled to the body, wherein the plurality of wheels includes at least one driven wheel and at least one steerable wheel;
a steering assembly comprising a steering mechanism adapted to receive steering inputs from a child sitting on the at least one seat, and a steering linkage adapted to convey the steering inputs to the at least one steerable wheel;
and
a drive assembly adapted to selectively drive the rotation of the at least one driven wheel;
and
wherein at least one of the plurality of wheels is a blow-molded wheel that is blow-molded in a 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 distance;
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 less a second predetermined threshold distance, wherein the fourth region of the first tread-molding portion is adjacent the third region of the second tread-molding portion when the second tread-molding portion is in the release position;
and
wherein, after the blow-molded wheel has been blow-molded into a shape corresponding to the shape of the mold cavity, the at least one second tread-molding portion must be moved from the molding position to the release position to permit separation of the first and second mold portions such that the blow-molded wheel can be released from the mold.

11 more elements

A children's ride-on vehicle, comprising:

a body having at least one seat sized for a child;
a plurality of wheels rotatably coupled to the body, wherein the plurality of wheels includes at least one driven wheel and at least one steerable wheel, wherein at least one of the plurality of wheels is a blow-molded wheel that comprises:
a blow-molded body having a tread surface, first and second sidewalls and an axis, wherein the body is configured to rotate about the axis, wherein the tread surface extends circumferentially around the body and extends between the first and second sidewalls;
a first region of the tread surface, wherein the first region is disposed between the first sidewall and a part line of the blow-molded body;
and
a second region of the tread surface, wherein the second region is disposed between the first region and the part line, wherein a first radial distance from the axis to the first region exceeds a second radial distance from the axis to the second region by at least a first predetermined threshold;
a steering assembly comprising a steering mechanism adapted to receive steering inputs from a child sitting on the at least one seat, and a steering linkage adapted to convey the steering inputs to the at least one steerable wheel;
and
a drive assembly adapted to selectively drive the rotation of the at least one driven wheel;
wherein:
the body is blow-molded in a mold comprising first and second mold portions, the first and second mold portions are configured to separate in a direction parallel to the axis, and the part line is defined by an interface between the first and second mold portions;
one of the first and second mold portions comprises first and second tread-molding portions, the first tread-molding portion is configured to mold the first region of the tread surface, and the second tread-molding portion is configured to mold the second region of the tread surface;
and
the first radial distance sufficiently exceeds the second radial distance such that at least a portion of the second tread-molding portion interferes with the first region of the tread surface and thereby impedes removal of the blow-molded body from the mold.

11 more elements

Dependencies are inferred from the claim text.