Patent ID: 7510466

Claim:
A shaft adapter for detachably mounting a grinding cup to the drive shaft of a grinding machine, said shaft adapter comprising: a collar portion slidably mountable on said drive shaft of said grinding machine, said collar portion having a passageway extending therethrough, said passageway having internal threads and a first end provided with an end surface and an open second end; a compressible drive sleeve member adapted to be received in said passageway of said collar portion, one end of said compressible drive sleeve member abutting said end surface of said first end of said collar portion, said compressible drive sleeve having a length less than the length of said passageway of said collar portion; and an extension member having a first end adapted to receive the free-end of the drive shaft and a second end for detachably receiving said grinding cup, said first end being received in said second end of said collar portion and having a threaded outer surface for engaging with the internal threads of said collar portion passageway; wherein the engagement between said collar portion and said extension member elastically deforms said compressible drive sleeve between said end surface of said collar portion and said first end of said extension member thereby creating a driving force between said drive shaft and said shaft adapted when said grinding machine is in use.