| 摘要 |
PROBLEM TO BE SOLVED: To prevent the difference of the thickness between a seam and a part adjacent to the seam by providing the half thickness of the belt to respective ends of the belt at the overlapped part and joining the ends through hard and high-strength fibers. SOLUTION: In overlapping and butting joint, respective ends of belt materials are provided with an upper and bottom engaging parts having the same length and about half thickness of the belt materials. The engaging parts are joined to each other by putting joint parts 16, 18 extending over an overlapping joint part 14 and/or the belt width. Suitable hard and high-strength fibers 20 capable of withstanding the processing temperature is used and arranged between the overlapped parts of the belt ends. Strong bonding can be obtained while keeping the fibers solids during the heat treatment for forming a seam by ultrasonic wave heating or impulse welding. Therefore, the difference of the height between the seam and a belt part adjacent to the seam region is prevented from substantially existing. |
