ASEISMIC BASE ISOLATION DEVICE, AND CRANE WITH ASEISMIC BASE ISOLATION DEVICE

PROBLEM TO BE SOLVED: To provide an aseismic base isolation device capable of preventing by a simplified and inexpensive configuration a problem that large stresses occur at supporting legs and structures in the event of a large-scale earthquake and also to provide a crane provided with the aseismic base isolation device.SOLUTION: An aseismic base isolation device comprises: restoring means 6, 6' for flexibly connecting end parts 2, 3 with each other so as to restore a lower side leg 1a and an upper side leg 1b in a straight line when the lower side leg 1a and the upper side leg 1b are bent in a left-right width direction of the lower side leg 1a and the upper side leg 1b at both ends of the left-right width direction; and trigger mechanisms 10, 10' which comprise overhang parts 20, 20' formed at the end part 2 of the lower side leg 1a so as to overhang further to both ends of the left-right width direction than the upper side leg 1b, arm parts 8 one end of which is pivoted on the overhang parts 20, 20' by fulcrum pins 7 to allow left and right turns, and weights 9 contacting the upper side leg 1b with centers of gravity W, provided at other ends of the arm parts 8, being positioned within the inside in the left-right width direction rather than directly above the fulcrum pins 7, and which allow the centers of gravity W of the weights 9 to turn beyond directly above the fulcrum pins 7 to the outside of the left-right width direction due to the effects of loads applied to the lower side leg 1a by an earthquake.