US Patent 7306685 Mounting device and method thereof

A mounting device and a method thereof for preventing a pellet from cracking or chipping when the pellet is mounted. A mounting device comprises a first head for mounting a second pellet on a first pellet already mounted and temporarily pressure-bonding the second pellet thereto by applying a first load and a second head for pressure-bonding the second pellet, which has been temporarily pressure-bonded by the first head, to the first pellet by applying a second load higher than the first load. The second head includes a protective sheet which is moved so that the unused portion is set with respect to each pellet, a ball which is supported rollably in arbitrary directions and in contact with the second pellet through the protective sheet, a spring for applying an elastic force in the direction of the protective sheet and applying the second load to the second pellet through the protective sheet, and a drive for rolling the ball on the protective sheet in contact with the second pellet.