Resin bonded abrasive article and method of manufacturing the same

Claim 1

A RESIN BONDED ABRASIVE BODY SUCH AS AN ABRASIVE WHEEL OR STONE COMPRISING A PLURALITY OF ABRASIVE GRAINS BONDED INTO THE SAID BODY BY A BOND COMPRISING BOTH A HEAT-HARDENING RESIN AND A THERMOPLASTIC RESIN SELECTED FROM THE GROUP CONSISTING OF POLYMERS AND COPOLYMER OF VINYL COMPOUNDS, SAID THERMOPLASTIC RESIN BEING INCOMPARTIBLE AND NON-REACTIVE WITH THE HEAT-HARDENABLE RESIN AND HAVING A SOFTENING POINT HIGH ENOUGH TO PREVENT IT FROM FLOWING THROUGH THE HEAT-HARDENABLE RESIN AND LOW ENGOUGH SO THAT THE PARTICLES OF THERMOPLASTIC RESIN ARE FLUXED AND WELD TOGETHER TO FORM AGGREGATIONS DURING THE HEAT-TREATMENT OF THE FORMED ARTICLE, SAID BOND BEING SO DISTRIBUTED THAT THE ABRASIVE GRAINS ARE SURROUNDED BY A COATING OF THE HEATHARDENED RESIN AND THE SAID THERMOPLASTIC RESIN IS POSITIONED BETWEEN THE SAID COATING OF HEATHARDENED RESIN SURROUNDING THE GRAINS AND A SECOND LAYER OF HEAT-HARDENED RESIN, THE THROUGH THE MOPLASTIC RESIN BEING SO DISTRIBUTED THROUGH THE HEAT-HARDENED RESIN AS TO MODIGY THE CHARACTERISTICS OF THE HEAT-HARDENED RESIN AND PROVIDE AN ABRASIVE ARTICLE CHARACTERIZED BY A HIGH EFFICIENCY AND CUTTING RATE AND THE ABILITY TO IMPART SUPERIOR FINISHES TO THE MATERIAL BEING ABRADED.