Back to results
US 4,130,619 AGranted
Apparatus and method of making hollow articles
AssigneeEktelon
InventorFranklin W. Held
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeEktelon
InventorFranklin W. Held
Estimating the term…
This invention is directed toward making hollow racquet ball balls. This is accomplished by molding a mass of vulcanizable elastic material to hollow semi-spherical form and heating the bulk of the material substantially fully to vulcanize it while simultaneously cooling a portion around the full edge so it is only partially vulcanized at the edge area thereof. Then two of such semi-spherical forms have the edges thereof abutted under some pressure to force the uncured edges together, and heat is then applied to the uncured edges of each half to fully vulcanize them and bind them together to form a unitary seamless ball thereform. Apparatus for forming the balls includes mold means defining a hollow semi-spherical cavity with a cooling chamber being provided at the open edge of the cavity that defines an edge of the formed hollow half sphere whereby a cooling medium can be circulated at the edge to prevent vulcanization thereof while the remaining part of the hollow half sphere is heated and vulcanized.
A method of making hollow articles from a vulcanizable, elastic material comprising the steps of;
Apparatus for use in molding and vulcanizing hollow semi-spherical articles from vulcanizable materials including a first mold member and a second mold member, said mold members defining a relatively thin walled hollow semi-spherical cavity, said semi-spherical cavity defining a circular edge, a cooling ring and an insulating ring, said cooling ring engaging said insulating ring and forming an annular cooling chamber therebetween, said cooling chamber being located adjacent to said circular edge.
Dependencies are inferred from the claim text.