| 摘要 |
In the conventional lace with knobby portions having elastic rubber core, there is difference in degree of stretch between both ends and core of the knobby portion. Therefore, there are a portion that is subjected to heavy stretching force and a portion that is subjected to no stretching force, and when large strain is accumulated at the boundary between the portions subjected to different stretching forces and the strain reaches the limit, the lace ruptures. In order to solve the above problem, we provide a lace provided with tubular lace body of elastic material, comprising knobby portions repeatedly placed at intervals, of which diameter vary depending on tension on the knobby portion in an axial direction. |
