Patent ID: 6971795

Claim:
An isolation bearing for supporting a superstructure relative to a base, said isolation bearing comprising: an isolation axis; a lower plate adapted for attachment to said base, said lower plate having an upwardly facing bearing surface; an upper plate adapted for attachment to said superstructure, said upper plate having a downwardly facing bearing surface; a pair of sidewall members fixed to said lower plate to define a pair of opposing wall surfaces extending parallel to said isolation axis of said bearing; a roller situated between and in rolling contact with said upwardly facing bearing surface of said lower plate and said downwardly facing bearing surface of said upper plate; at least one of said upwardly facing bearing surface and said downwardly facing bearing surface being configured to provide a normal reference position of said roller along said isolation axis toward which said roller is biased under gravitational loading; and non-linear damping means for providing a damping force for dissipating kinetic energy associated with displacement of said lower plate relative to said upper plate along said isolation axis, said damping force being a non-linear function of the velocity of said lower plate relative to said upper plate.