Patent ID: RE38742

Claim:
A grinding device comprising a cylindrical member with an outer bushing unit, an interior bushing unit, an upper control unit, an expanding unit, and a locking mechanism; wherein the outer bushing unit receives a grinding sleeve, and has, when the locking mechanism is in an unlocked position, a first outer diameter of D, and a height H; wherein the interior bushing unit receives a rotatable shaft, has, when the locking mechanism is in an unlocked position, a second outer diameter of I, which is less than D, and a height J, which is less than H; wherein the expanding unit extends from within the upper control unit and at least portions thereof between the outer bushing unit and interior bushing unit, and the expanding unit has a first protrusion below and contacting the outer bushing unit and a second protrusion below and contacting interior bushing unit; wherein the locking mechanism is interconnected to the upper control unit so that when the locking mechanism is in the unlocked position, the grinding sleeve can be placed on or taken off the outer bushing unit and the device can be placed on or taken off a rotatable shaft; and when the locking mechanism is in the locked position, the locking mechanism pulls the expanding unit towards the upper control unit and pushes the upper control unit towards the expanding unit which expands the outer diameter and shortens the height of the outer bushing unit, and expands the interior diameter and shortens the height of the interior bushing unit.