Abrasive tool comprising bonded abrasive element cemented to supporting element

Claim 1

AN ABRASIVE TOOL ADAPTED FOR BOTH WET AND DRY GRINDING COMPRISING A BONDED ABRASIVE ELEMENT ATTACHED TO A RIGID SUPPORTING ELEMENT BY A CEMENT COMPRISING THE SOLIDIFIED AND HEAT-HARDENED REACTION PRODUCT OF A LIQUID PHENOL-FORMALDE100 PARTS OF A NORMALLY LIQUID PHENOL-FORMALDEHYDE CONDENSATION PRODUCT, ABOUT 10-400 PARTS OF A WATER-INSOLUBLE PARTIAL ACETAL OF POLYVINYL ALCOHOL AND AN ALDEHYDE SELECTED FROM THE GROUP CONSISTING OF HUTYRALDEHYDE, FORMALDEHYDE AND ACETALDEHYDE AND A VOLATILE SOLVENT, SAID CEMENT HAVING THE CHARACTERISTIC OF AIR DRYING TO A TACKY CONDITION SUCH THAT THE ABRASIVE ELEMENTS ARE HELD IN PLACE STRONGLY ENOUGH TO PERMIT HANDILING WITHOUT DISPLACEMENTT OF THE SAID ELEMENTS WITH RESPECT TO THE BACKING ELEMENT AND IN A CURED CONDITION BEING STRONGLY ADHERENT TO VARIOUS TYPES OF SUPPORTING ELEMENTS ADHERENT TO VARIABRASIVES, STRONY ENOUGH AND TO SUFFICIENT RESILIENCE TO ABSORB THE STRESSES OCCASIONED BY THE DIFFERENCE IN COEFFICIENT OF THE EXPANSION BETWEEN THE ABRASIVE ELEMENT AND THE BACKING AND IN THE USE OF THE TOOL, HIGHLY RESISTANT TO SHOCK, AND HAVING SUFFICIENT HEAT-RESISTANCE TO PERMIT USE OF THE TOOL FOR DRY GRINDING AND SUFFICIENT MOISTURE-RESISTANCE TO WITHSTAND THE COOLANTS USED IN WET GRINDING.