| 摘要 |
<p>PURPOSE:To provide a small and inexpensive contact breaker such as a brake, clutch or the like by bringing a wire-like shape memory alloy which is held by a first material at the one portion thereof and wound by a second material in press contact with the second material when the shape memory alloy tends to return into the memorized length. CONSTITUTION:On the part of the outer periphery of a rotary body 3 fixed on a rotating shaft 2 a wire-like shape memory alloy 8 made of Ti-Ni alloy is wound and the both ends thereof are fixed with a fixing fitting 4 and a contact fitting 6. As the shape memory alloy 8 tends to return into the memorized length, it is brought in press contact with the rotary body 3 while in the condition where the shape memory alloy 8 is elongated to a certain degree it is brought in light contact with the rotary body 3. When current is not applied, the alloy 8 becomes at the circumference temperature and is brought in light contact with the outer periphery of the rotary body 3 so as not to exert a braking force to the rotation. When current is applied, the alloy 8 is heated up to the range of a predetermined temperature and tends to return into a short length so as to be in press contact with the rotary body 3, thus braking force being generated to the rotation. Therefore, it is possible to miniaturize the device with a small structure and reduce a production cost.</p> |
