Abstract: A receiving plate for opposite ends of an upper shoe is placed between claws at opposite ends of a lower shoe, rubber packings are detachably provided in the gap spaces between the respective claws and the receiving plate, and the rubber packing consists of an inner plate, a first buffer rubber layer, a middle plate, a second buffer rubber layer and an outer plate. The first buffer rubber layer is made of two flat rubber plates with a plurality of rubber truss plates connected therebetween in a zig-zag form so as to form a large number of vacancies within the first buffer rubber layer, and hence, an impact force caused by an earthquake is absorbed by the rubber packing to prevent the receiving plate or the claws from being destroyed.