Abstract: The transferring device is provided with a cylindrical partition wall formed with reduced thickness portions 14. A floating carrier 3 is disposed around the cylindrical partition wall and is provided with target pieces 15. The reduced thickness portion 14 is formed by recessing the outer peripheral face 1a of the partition wall 1 along the lengthwise direction thereof. Electromagnets 10, 11 are mounted on an actuating block 4 within the tubular partition wall 1 in opposed relation to the reduced thickness portions 14. The target piece 15 are also opposed in alignment with the reduced thickness portions 14. The partition wall 1 has a sufficient thickness other than the reduced thickness portions 14 so as to ensure physical strength of the partition wall 1. Magnetic force is applied from the electromagnets 10, 11 to the target pieces 15 through the reduced thickness partition 14, thereby supporting the floating carrier 3 with a reduced amount of an exciting current flowing through the electromagnets 10, 11.

Abstract: In a method of internal grinding with a grinding wheel composed of cubic boron nitride, in order to maintain the processing accuracy of workpieces in each grinding cycle after the completion of dressing, the grinding wheel undergoes a corrective retracting movement from the roughly ground surface of a workpiece at the larger amount than the normal retraction amount in the predetermined time or in a time for grinding the predetermined pieces of the workpiece just after completion of dressing.