Patent ID: 6612151
Filing Date: 2003-09-02
Classification: A63B,G01N

Abstract:
A device for determining the friction between a games ball and a playing surface, comprising:a rigid pendulum mounted by a pivot at a first end thereof to a frame placed on the surface, allowing the pendulum to describe an arc by swinging in a first plane vertical to the surface; a holder for holding a ball at or adjacent a second end of the pendulum; means for adjusting the position of the pivot relative to the surface, and/or for adjusting the position of the ball relative to the pivot, to ensure contact of the ball with the surface over a desired length of a lower portion of the arc; and means for measuring the extent of the arc described by the pendulum following contact of the ball with the surface, so as to allow determination of the friction between the two; wherein the holder is attached to the pendulum by a rotatable shoe arranged such that: the shoe is able to rotate relative to the pendulum in a second plane perpendicular to the first plane and which passes through the longitudinal axis of the pendulum such that the centre of the ball can move in a controlled manner in an approximately radial direction with respect to the pendulum pivot; and at a point where the pendulum is vertical, the centre of the ball lies on a vertical line passing through that pivot.