US Patent 7144315 Grinding wheel

A grinding wheel including a ring-shaped wheel, a first fixing cap, a second fixing cap and a buffer member. The ring-shaped wheel has a fixing section and a working section formed along outer circumference of the fixing section. The first and second fixing caps are respectively mounted on two sides of the fixing section. The buffer member is positioned between the first and second fixing caps for reducing shock produced in operation. The circumference of the buffer member is formed with multiple movable vanes. When the grinding wheel is rotated at high speed, the centrifugal force will deform the movable vanes of the buffer member to lean on the ring-shaped wheel for supporting the working section thereof.