Molding of a shock resistant transparent polymer sphere

Claim 1

A method of manufacturing a shock resistant transparent polymer sphere with a disc, having a symbol inked on each of its opposite faces, diametrically incorporated in the sphere with the center of gravity of the disc coincident with the center of gravity of the sphere, including the steps of: (a) providing a mold defining a spherical cavity with a single fill opening at its top; (b) providing a given transparent polyester resin in liquid form preparatory to pouring into said mold, said resin having a given index of refraction and a given density after curing; (c) providing an opaque disc of thermoplastic material having substantially the same density as said given density but constituting a plastic different from said polyester resin, said material having the characteristics of mechanically and chemically bonding with said resin without any surface deterioration and which material swells slightly upon extended contact with said polyester resin; (d) providing an ink constituting a polyester and thermoplastic alloy which will function as a catalyst for said thermoplastic resin and will bind to both said disc and said resin; (e) providing a holder in the form of an annular ring having a plurality of equally circumferentially spaced lugs extending radially inwardly equal distances, said ring being of thermoplastic material which will mechanically and chemically bond with said polyester resin, and which has the same index of refraction, transparency, Rockwell hardness and surface finishing characteristics as said polyester resin after curing; (f) silk-screening said symbol on each of the opposite sides of said disc with said ink; (g) positioning said disc in central coplanar relationship in said ring, said lugs engaging the periphery of said disc at equal circumferentially spaced points to hold it centered to provide a disc-ring assembly; (h) positioning said disc-ring assembly in said spherical cavity of said mold so that the center of said disc coincides with the center of said spherical cavity; (i) pouring said resin into said fill opening to completely fill said cavity and thereby encapsulate said disc-ring assembly; (j) removing the polyester resin with said disc-ring assembly encapsulated therein after curing, said ring being substantially invisible; and (k) polishing the surface of the resulting sphere to provide said shock resistant transparent polymer sphere, the bonding of the disc and ink to each other and to the polyester resin resulting in an embossed characteristic for the symbols as a result of said slight swelling of the disc material and the further bonding of the ring with the disc and resin resulting in a sphere in which shock is absorbed by the disc, ink and ring as well as the resin as though the entire sphere were homogeneous throughout.

Claim 2

A method of manufacturing a shock resistant transparent polymer sphere with a disc, having a symbol inked on each of its opposite faces, diametrically incorporated in the sphere with the center of gravity of the disc coincident with the center of gravity of the sphere, including the steps of: (a) providing a mold defining a spherical cavity with a single fill opening at its top; (b) providing a given transparent polyester resin in liquid form preparatory to pouring into said mold, said resin having a given index of refraction and a given density after curing; (c) providing an opaque disc of thermoplastic material having substantially the same density as said given density but constituting a plastic different from said polyester resin, said material having the characteristics of mechanically and chemically bonding with said resin without any surface deterioration and which material swells slightly upon extended contact with said polyester resin; (d) providing an ink constituting a polyester and thermoplastic alloy which will function as a catalyst for said thermoplastic resin and will bind to both said disc and said resin; (e) providing a holder in the form of an annular ring having a plurality of equally circumferentially spaced lugs extending radially inwardly equal distances, said ring being of thermoplastic material which will mechanically and chemically bond with said polyester resin, and which has the same index of refraction, transparency, Rockwell hardness and surface finishing characteristics as said polyester resin after curing; (f) silk-screening said symbol on each of the opposite sides of said disc with said ink; (g) positioning said disc in central coplanar relationship in said ring, said lugs engaging the periphery of said disc at equal circumferentially spaced points to hold it centered to provide a disc-ring assembly; (h) positioning said disc-ring assembly in said spherical cavity of said mold so that the center of said disc coincides with the center of said spherical cavity; (i) pouring said resin into said fill opening to completely fill said cavity and thereby encapsulate said disc-ring assembly; (j) removing the polyester resin with said disc-ring assembly encapsulated therein after curing, said ring being substantially invisible; and (k) polishing the surface of the resulting sphere to provide said shock resistant transparent polymer sphere, the bonding of the disc and ink to each other and to the polyester resin resulting in an embossed characteristic for the symbols as a result of said slight swelling of the disc material and the further bonding of the ring with the disc and resin resulting in a sphere in which shock is absorbed by the disc, ink and ring as well as the resin as though the entire sphere were homogeneous throughout.

Claim 3

A method of manufacturing a shock resistant transparent polymer sphere with a disc, having a symbol on each of its opposite faces, diametrically incorporated in the sphere with the center of gravity of the disc coincident with the center of gravity of the sphere, including the steps of: (a) providing a mold defining a spherical cavity with a single fill opening at its top; (b) providing a given transparent polyester resin in liquid form preparatory to pouring into said mold, said resin having a given index of refraction and a given density after curing; (c) providing an opaque disc of thermoplastic material having substantially the same density as said given density but constituting a plastic different from said polyester resin, said material having the characteristics of mechanically and chemically bonding with said resin without any surface deterioration and which material swells slightly upon extended contact with said polyester resin; (d) providing a holder in the form of an annular ring having a plurality of equally circumferentially spaced lugs extending radially inwardly equal distances, said ring being of thermoplastic material which will mechanically and chemically bond with said polyester resin, and which has the same index of refraction, transparency, Rockwell hardness, specific gravity and surface finishing characteristics as said polyester resin after curing; (e) providing said symbol on each of the opposite sides of said disc; (f) positioning said disc in central coplanar relationship in said ring, said lugs engaging the periphery of said disc at equal circumferentially spaced points to hold it centered to provide a disc-ring assembly; (g) positioning said disc-ring assembly in said spherical cavity of said mold so that the center of said disc coincides with the center of said spherical cavity; (h) pouring said resin into said fill opening to completely fill said cavity and thereby encapsulate said disc-ring assembly; (i) removing the polyester resin with said disc-ring assembly encapsulated therein after curing, said ring being substantially invisible; and (j) polishing the surface of the resulting sphere to provide said shock resistant transparent polymer sphere, the bonding of the disc to the polyester resin resulting in an embossed characteristic for the symbols as a result of said slight swelling of the disc material and the further bonding of the ring with the disc and resin resulting in a sphere in which shock is absorbed by the disc and ring as well as the resin as though the entire sphere were homogenous throughout.

Claim 4

A method of manufacturing a shock resistant transparent polymer sphere with a disc, having a symbol on each of its opposite faces, diametrically incorporated in the sphere with the center of gravity of the disc coincident with the center of gravity of the sphere, including the steps of: (a) providing a mold defining a spherical cavity with a single fill opening at its top; (b) providing a given transparent polyester resin in liquid form preparatory to pouring into said mold, said resin having a given index of refraction and a given density after curing; (c) providing an opaque disc of thermoplastic material having substantially the same density as said given density but constituting a plastic different from said polyester resin, said material having the characteristics of mechanically and chemically bonding with said resin without any surface deterioration and which material swells slightly upon extended contact with said polyester resin; (d) providing a holder in the form of an annular ring having a plurality of equally circumferentially spaced lugs extending radially inwardly equal distances, said ring being of thermoplastic material which will mechanically and chemically bond with said polyester resin, and which has the same index of refraction, transparency, Rockwell hardness, specific gravity and surface finishing characteristics as said polyester resin after curing; (e) providing said symbol on each of the opposite sides of said disc; (f) positioning said disc in central coplanar relationship in said ring, said lugs engaging the periphery of said disc at equal circumferentially spaced points to hold it centered to provide a disc-ring assembly; (g) positioning said disc-ring assembly in said spherical cavity of said mold so that the center of said disc coincides with the center of said spherical cavity; (h) pouring said resin into said fill opening to completely fill said cavity and thereby encapsulate said disc-ring assembly; (i) removing the polyester resin with said disc-ring assembly encapsulated therein after curing, said ring being substantially invisible; and (j) polishing the surface of the resulting sphere to provide said shock resistant transparent polymer sphere, the bonding of the disc to the polyester resin resulting in an embossed characteristic for the symbols as a result of said slight swelling of the disc material and the further bonding of the ring with the disc and resin resulting in a sphere in which shock is absorbed by the disc and ring as well as the resin as though the entire sphere were homogenous throughout.