Seismic isolator

摘要

A seismic isolator has a sliding plate fixed on the lower surface of a building, a connecting plate underlying the sliding plate, an elastic first support disposed between the connecting plate and a foundation of the building to support the building, a second support disposed between the connecting plate and the foundation and urged by a biasing force of a spring member such that its upper end is brought into tight contact with the lower surface of the connecting plate, and a jack for adjusting the biasing force of the spring member. A frictional force acting between the sliding plate and the connecting plate is larger than that between the connecting plate and the upper end of the second support.