Magnetic ball production method

Claim 1

A method of making a sheet containing a multiplicity of magnetically polarized bodies which are thereby capable of being freely rotated under the influence of a magnetic field applied to the sheet, said bodies respectively comprising a first portion of a first color of one magnetic polarity and a second portion of a second contrasting color and of opposite magnetic polarity comprising the steps of: coating said bodies with a thermoplastic material; disposing said coated bodies in a planar array; encapsulating said array within a sheet of plastic material, said encapsulating material being chosen to have a melting point higher than the melting point of said thermoplastic material; and heating said sheet to at least render said thermoplastic material molten, said heating being carried out at a temperature which is below the melting point of said encapsulating material whereby said magnetic bodies are caused to be freely rotatable under the influence of a magnetic field applied to said sheet.

Claim 2

A method of making a sheet containing a multiplicity of magnetically polarized bodies which are capable of being freely rotated under the inflUence of a magnetic field applied to said sheet, said bodies respectively comprising a first portion of a first and light color of one magnetic polarity and a second portion of a second and dark color and of the opposite magnetic polarity comprising the steps of: coating said bodies with a thermoplastic material; disposing said coated bodies in a planar array; encapsulating said array within a sheet of transparent plastic material, said plastic material being chosen to have a melting point higher than the melting point of said thermoplastic material; and heating said sheeting to at least render said thermoplastic material molten, said heating being carried out at a temperature which is below the melting point of said plastic material whereby said magnetic bodies are caused to be freely rotatable under the influence of a magnetic field applied to said sheet.

Claim 3

A method of making a sheet containing a multiplicity of magnetically polarized bodies which are capable of being fully rotated under the influence of a magnetic stylus applied to said sheet, said bodies respectively comprising a first portion of a first and light color of one magnetic polarity and a second portion of a second and dark color and of the opposite magnetic polarity comprising the steps of: slicing a plurality of relatively long cylinders of magnetic material into respective groups of substantially equal length relatively short cylinders, said magnetic material which is utilized comprising semicylinders of light and dark colored magnetic materials respectively attached to each other along their diametric surfaces; maintaining the respective groups of sliced relatively short cylinders in abutting relationship and coating said groups with a thermoplastic material; contracting uniformly under pressure, the diameters of said coated elongated cylinders to force said thermoplastic material between said short cylinders to longitudinally space said short cylinders from each other within said thermoplastic material; circumferentially notching said coated elongated cylinders at points between the abutting ends of adjacent short cylinders; arranging said notched elongated cylinders in substantially parallel relationship in a planar array; encapsulating said array in a transparent encapsulating material in a thin parallelepiped configuration to produce said sheet, said encapsulating material being chosen to have a melting point higher than the melting point of said thermoplastic material; and heating said sheet to expel said thermoplastic material therefrom to thereby produce a multiplicity of hollow chambers, each of said chambers containing one of said short cylinders, said heating being carried out at a temperature which is at least the melting point of said encapsulating material whereby said thermoplastic material can be flowed out of said chambers through openings in said encapsulating material.

Claim 6

A method of making a sheet containing a multiplicity of spaced, magnetically polarized bodies which are capable of being fully rotated under the influence of a magnetic stylus applied to said sheet, said bodies respectively comprising a first Portion of a first and light color and of one magnetic polarity and a second portion of a second and dark color and of the opposite magnetic polarity comprising the steps of: slicing a plurality of relatively long cylinders of magnetic material into a plurality of relatively short cylinders, said cylinders consisting of substantially semicylindrical light and dark colored portions; coating said short cylinders at least partly with a thermoplastic material; permitting said coated short cylinders to fall through a zone having a temperature at least sufficiently high to cause said thermoplastic material to melt and thereby cause said thermoplastic material to become substantially uniformly distributed around said cylinders and to cause said coated cylinders to assume a substantially spherical configuration as they fall through said hot zone, and to then fall through a zone having a temperature sufficiently low to cause said thermoplastic material to harden about said short cylinders; disposing said coated cylinders in a planar array; and encapsulating said array in a transparent plastic material in a thin parallelepiped configuration to produce said sheet, said encapsulating material being chosen to have a melting point higher than the melting point of said thermoplastic material whereby, upon the heating of said sheet to a point at which said thermoplastic material becomes molten, said cylinders can be freely rotated under the influence of a magnetic stylus applied to said sheet.