| 摘要 |
An turning shaft 1 which turns a torch with keeping it on a normal line to the turning shaft is connected with an end of an first rotation shaft 2 which is arranged at a right angle to the turning shaft 1. A second rotation shaft 3 is connected with the first rotation shaft 2. Both the rotation shafts are connected with each other through a first arm 4, and a second arm is connected with with the rotation shaft 3. a first fixed gear 14 is fixed to the first rotation shaft 2, and a second fixed gear 15 is fixed to the second arm 5. a middle gear 16 is arranged between both the fixed gears, and a rotation axis 16c is fixed to the first arm 4. a motor 17 is mounted above the upper bent portion 4a and a gear 17a is engaged with the first fixed gear 14. While rotating the first arm by angle &thetas; in the direction of arrow a, the second arm 5 is rotated by angle 2&thetas; in the direction of arrow b, wherein the angle made between the extension of line of the turning shaft and the extension of line of the second arm 5 is &thetas;. <IMAGE> |
