MOLDED ARTICLE AND IMPROVED VENTING ASSEMBLY FOR A ROTATING MOLD
A molded article with an axis of rotation about a central axis having an outer interface element, an inner interface element, and a plurality of web spokes positioned therebetween. The common surfaces of the inner and outer interface elements and a pair of adjacent web spokes form a void space. The radially inner surface of an interface element common to one of the voids has a maximum radius of curvature in the longitudinal direction at any given point less than the distance between that point and the axis of rotation.
1 . A non-pneumatic tire having an axis of rotation about a central axis, said tire comprising an outer interface element having a circumference and an axial width, an inner interface element having a circumference and an axial width, a plurality of web spokes positioned therebetween, and said web spokes being oriented in a generally radial direction, and the common surfaces of said inner interface element, said outer interface element, and a pair of adjacent web spokes forming a void space, wherein said surface of said outer interface element common to said void space possesses a longitudinal curvature having a radius of curvature in the longitudinal direction, whereas the maximum radius of curvature in the longitudinal direction at any given point along said surface of said outer interface element common to said void space is less than the distance between said point and said central axis of said tire.
2 . The molded article according to claim 1 , wherein said radius of curvature of said surface of said outer interface element has a value that is between ninety five percent of the maximum distance between the axis of rotation and said surface of said outer interface element and the maximum longitudinal distance between the opposing surfaces of said pair of adjacent web spokes.
3 . A non-pneumatic tire having an axis of rotation about a central axis, said tire comprising an outer interface element having a circumference and an axial width, an inner interface element having a circumference and an axial width, a plurality of web spokes positioned therebetween, and said web spokes being oriented in a generally radial direction, and the common surfaces of said inner interface element, said outer interface element, and a pair of adjacent web spokes forming a void space, wherein said surface of said outer interface element common to said void space between said adjacent web spokes possesses a longitudinal curvature about at least one axes, each said at least one axes is positioned between said central axis and said surface of said outer interface element common to said void space and the each at least one axes is parallel to said central axis.
4 . The non-pneumatic tire according to claim 3 , wherein said at least one axis is comprised of a first axis, a second axis and a third axis.
5 . The non-pneumatic tire according to claim 4 , wherein said surface of said outer interface element common to said void space is comprised of a first curved portion with a radius of curvature extending about said first axis, a second curved portion with a radius of curvature extending about said second axis, and a third curved portion with a radius of curvature extending about said third axis, wherein said second curved portion is between and continuous with said first curved portion and said third curved portion.
7 . A mold for a molded article comprising an upper mold part and a lower mold part capable of rotation about a central axis, said upper mold part further comprising a first set of cores projecting downward from the top of the mold and terminating axially in contact with said lower mold part to form a first set of voids in the molded article, said lower mold part comprising a second set axially oriented cores or fingers projecting upward from the bottom of the mold and terminating axially in contact with said upper mold part and terminating axially in contact with said upper mold part to form a second set of voids in the molded article, wherein a void space between said first set of cores and said second cores forms a radially oriented web spoke in the molded article, a radially outer portion of said mold forming an outer interface element in the molded article and a radially inner portion of said mold forming an inner interface element in the molded article, wherein said radially outer portion of said mold forming said outer interface element in the molded article possesses a curvature in a longitudinal direction having at least one radius of curvature about at least one axis, each of said at least one axis always positioned between said first axis and said surface of said outer interface element common to said void space.
8 . The mold according to claim 7 , wherein said at least one axis is comprised of a first axis, a second axis and a third axis.
9 . The non-pneumatic tire according to claim 8 , wherein said radially outer portion of said mold forming said surface of said outer interface element common to said void space is comprised of a first curved portion with a radius of curvature extending to said first axis, a second curved portion with a radius of curvature extending to said second axis, and a third curved portion with a radius of curvature extending to said third axis, wherein said second curved portion is between and continuous with said first curved portion and said third curved portion.
10 . The non-pneumatic tire according to claim 8 , wherein said surface of said outer interface element common to said void space is comprised of a first curved portion with a radius of curvature extending to said first axis, a second curved portion with a radius of curvature extending to said second axis, and a third curved portion with a radius of curvature extending to said third axis, wherein said second curved portion is adjacent to and continuous with said first curved portion and said third curved portion.