Concentric steel spherical shells (or semiespherical)
at least two sheels, sparated by an arrangement (icosahedron, for example) of rubber pads.
It works in similar way that a rubber springs composed by a metalic plain washer joined with a rubber washer, then joined with a metalic washer and...
You could make a search for "air springs" for example those manufactured by Firestone Indl. Products or make a rubber spring in a spherical shape, or concentric spherical cases separated by ruber pads.
Sincerely
Shieldmaker