| 摘要 |
The ring (42) has a square, rectangular or circular shaped section with a diameter ranging from 1 to 3 millimeters, where the ring is continuous and made of a super-elastic metal material such as shape memory alloy material e.g. copper alloy and alloy of copper, aluminum and beryllium. The material includes a maximum elastic deformation capacity comprised between 2-10 percentages, where the material resists to high temperature of 400 degree Celsius. |
