VIBRATION ISOLATION DEVICE FOR LOADING ARM

PROBLEM TO BE SOLVED: To absorb earthquake forces by a simple structure, by arranging horizontally a support plate on a displacement member fixed to a rising pipe and providing three or more springs connected to the support plate at one end and connected to the ground surface side at the other end and arranged along the nearly horizontal direction. SOLUTION: A displacement member 11 is arranged on a pier 6 and the support plate 9 of the displacement member 11 is laid horizontally. Four first brackets 17 are fixed so as to constitute a cross-shape respectively at the middle of the four edges of the surface. Four second brackets 20 are fixed in the same way oppositely to the first brackets. The ends 18C of respective links 18 and respective second brackets 20 are connected to each other through three or more springs 21. Even when an earthquake occurs and the pier vibrates, the displacement member 11 slides and the vibration transmitted from the pier 6 to the loading arm 1 is reduced to only the vibration corresponding to the frictional resistance of the displacement member 11 and hence, the earthquake force acting on the loading arm 1 is lessened.