| 摘要 |
PURPOSE:To closely couple a pair of yoke pieces by caulking by forming a pair of extruded ears which gradually becomes thinner as it comes to the end, bending the band region into the recessed portion of side wall, allowing said region to bite into the area between extruded ears. CONSTITUTION:The first and the second yoke pieces 1, 5 are combined and thereafter the band region 4 is bent inward. Thereby, it is located on a pair of extruded ears 8a, 8b of the band region 4. At this time,it is desirable that a pair of extruded ears 8a, 8b enter a little into the slot 3. Thereafter, when the intermediate part of band region 4 is bent, the intermediate part of band region 4 bites between the extruded ears 8a, 8b and the caulking terminates. Since the extruded ears 8a, 8b are formed in such a way as gradually becoming thinner as it comes to the end, the side wall open end edge of yoke piece 1 is strongly attracted toward the side wall of yoke piece 5 during said biting process, both yoke pieces 1, 5 are integrally coupled under the condition that these are closely in contact with each other. |
