US Patent 7494422 Vertically mass balanced putter

The components parts of a putter are weighted and assembled to form a putter in which the vertical center of mass lies within the horizontal length of a preferred striking surface on the face of the putter. Vertically mass balanced putters with flat bottom surfaces stand alone on the green without external support, permitting the golfer to view the geometric relationship of ball, cup, putter and topography of the green from various distances and perspectives. Distribution of mass of the putter equally on opposite sides of its vertical axis permits the putter to be swung in a pendulum motion without imparting yaw to the moving striking face of the putter.