Patent ID: 7584578

Claim:
A seismic energy damping apparatus for a building structure, said apparatus comprising: a pair of building structure members juxtaposed to one another, said building structure members being substantially immovable relative to one another in the absence of seismic energy delivered to said building by a seismic event, and being subject to relative lateral movement during a seismic event, each of the pair of building structure members defining a respective one of a pair of holes generally aligned with one another; a pair of friction washers each connected to a respective one of said pair of building structure members, said pair of friction washers confronting one another and defining respective friction surfaces; said pair of friction surfaces cooperating with one another and moving relative to one another during a seismic event to frictionally dissipate seismic energy; a resilient tie bolt extending through said aligned pair of holes and urging the pair of building structure members and said pair of friction surfaces toward one another with a determined force, thus to substantially determine the frictional damping force effective between said pair of building structure members and said pair of friction washers connected thereon; and said pair of holes being oversized with respect to said tie bolt thus to provide room for said building structure members to move laterally relative to one another during the seismic event without binding on said tie bolt; wherein one of said pair of friction washers is defined by an annular flange portion of a flanged tubular member received in a respective hole defined by one of said building structure members.