| 摘要 |
A first motor is fitted to a threaded shaft onto which first and second nuts are screwed, a first holder to which a second motor for rotating the first nut is fixed is fitted to the shaft, the first holder is provided with a first bracket to which one ends of first and second connecting rods are rotatably connected, a second bracket is rotatably connected to ends of the first and second connecting rods opposite to the end where the first bracket is installed so that the first and second connecting rods are put in parallel positions, a second holder is secured to the second nut, the first holder and the second holder engage with a guide rail installed in parallel with the first shaft so as to be moved along the guide rail when the first shaft rotates, the second holder is provided with a third bracket, one end of a third connecting rod is rotatably connected to the third bracket, and central part of the second connecting rod is rotatably connected to an end of the third connecting rod opposite to the end where the third bracket is installed. |
