Roller assembly and method and apparatus for making it

Claim 1

A ROLLER ASSEMBLY COMPRSING: (A) A ROLLER HAVING AN AXIAL OPENING THROUGH IT, (B) A SHAFT DISPOSED IN THE OPENING IN THE ROLLER, (C) THE SHAFT HAVING A SMOOTH EXTERNAL FLANGES ON A PAIR OF OUTWARDLY EXTENDING INTEGRAL FLANGES ON OPPOSITE SIDES OF THE ROLLER, (D) THE ROLLER DEFINING A PLURALITY OF RADIAL INTEGRAL PROJECTIONS EXTENDING INTO THE AXIAL OPENING TO MAKE A SLIDING FIT AROUND THE SMOOTH EXTERNAL SURFACE OF THE SHAFT, THE INNER PORTIONS OF THE PROJECTIONS DEFINING THE EFFECTIVE DIAMETER OF THE OPENING THROUGH THE ROLLER, (E) THE FLANGES HAVING AN EFFECTIVE OUTER DIAMETER GREATER THAN THE EFFECTIVE DIAMETER OF THE AXIAL OPENING THROUGH THE ROLLER TO PREVENT THE ROLLER FROM SLIPPING OFF OF THE SHAFT, (F) THE ROLLER AND SHAFT BEING FORMED IN AN ASSEMBLED POSITION OF THE SAME PLASTIC MATERIAL BY INJECTING THE PLASTIC INTO A MOLD HAVING A COMMON ANNULAR WALL FOR PROVIDING AN ANNULAR SPACE BETWEEN THE SHAFT AND ROLLER, (G) THE FLANGES OF THE SHAFT AND THE INWARD PROJECTIONS OF THE ROLLER HAVING SUFFICIENT RIGIDITY AFTER COMPLETION OF THE MOLDING OPERATION TO PREVENT THE ROLLER BEING REMOVED FROM THE SHAFT WITHOUT RUPTURING THE PLASTIC.