Patent ID: 7811155

Claim:
A grinding cup in a series of grinding cups, each grinding cup in the series comprising a different size and profile, for grinding hard metal inserts or working tips of drill bits (percussive or rotary), tunnel boring machine cutters (TBM), and raised bore machine cutters (RBM) to restore them to substantially their original profile, wherein said working tips have a diameter of about 6 mm to 26 mm, each of said grinding cups in the series having a replaceable lower grinding member with a centrally disposed convex recess formed in a bottom surface of said grinding cup, said recess having a size and desired profile of the working tip to be ground and a re-useable upper drive connection member adapted to detachably connect to an output drive shaft of a grinding machine and standardized across a plurality of profiles and sizes of working tips to be ground, said grinding member having a grinding section having top and bottom surfaces, the centrally disposed convex recess being formed in the bottom surface of said grinding section and a support section adjacent the top surface of said grinding section and said grinding member including means to connect the grinding member to the drive connection member, and said upper drive connection member having a first section adapted for connection to said grinding member and a second section adapted to detachably connect to an output drive shaft of a grinding machine, wherein the means to connect the grinding member to the drive connection member is selected from the group consisting of a press fit, shrink fit, adhesive, solder, and friction welding such that the grinding member can be disconnected only by a manufacturer from the drive connection member when it becomes worn to permit the drive connection member to be attached to another grinding member.