| 摘要 |
PROBLEM TO BE SOLVED: To provide an aseismic base isolation in which it can be easily applied as an aseismic base isolation for a large-sized unit, its structure can be simplified, its assembly can be easily carried out and a rotation of a movable carriage in a direction &thetas; axis can be prevented.SOLUTION: This invention comprises: a base 2 provided with two dish-like recesses 21; a movement board 3 provided with two dish-like recesses 31; balls 4 arranged between the two dish-like recesses 21 and between the two dish-like recesses 31; a holder 5 composed of two holding plates 51, 52 holding the balls 4 from above and below to connect them; a bridge 23 at the base side passing over the lower holding plate 51 of the two holding plates 51, 52; and a bridge 33 at the movement board side passing below the upper holding plate 52. A &thetas; axis rotation preventive member 8 for constantly holding a crossing angle between the holding plates 51, 52 and the bridges 23, 33 while the holding plates 51, 52 and the bridges 23, 33 slide in response to a motion of the movement board 3 is held at least one of between the lower holding plate 51 and the bridge 23 at the base side, or between the upper holding plate 52 and the bridge 33 of the movement board side. |
