Patent attributes
Method and apparatus for measuring the coefficient of rolling friction or speed of a horizontal surface over which a round object is rolled such as a putting green encountered in the game of golf. The method includes a device for launching a ball across the surface at a constant and consistent velocity. An included timing device is triggered to start counting the elapsed time when the ball exits the launching device and continues counting until the ball has decelerated to a stop. At the instant the ball ceases moving the timer is triggered to terminate the count. The time required for a body with a specific velocity to come to rest after experiencing constant deceleration is determined by the laws of motion. The coefficient of friction or “speed” of the green which is proportional to the amount of deceleration may then be calculated. This time measurement is therefore sufficient to determine the speed of the green surface which may be reported as an equivalent “stimp” value.
