US Patent 8449412 Ball bat having performance adjusting annular member

A ball bat extending about a longitudinal axis. The bat includes a bat frame, a knob and an annular member. The bat frame has a handle portion and a tubular barrel portion. The bat has a proximal end, a distal end, a center of percussion and a length of at least thirty inches. The barrel portion has an inner surface. The knob is coupled to the handle portion. The annular member is coupled to the inner surface. The annular member has a center of mass and is positioned within the barrel portion such that the center of mass is longitudinally spaced apart from the center of percussion by a first distance of at least 0.25 inches. The annular member increases the moment of inertia of the bat measured about an axis positioned six inches from the base of the knob of the bat by no more than twenty percent.