Bowling ball

Abstract

A bowling ball wherein the weights of the inner core and the encapsulating mass are varied through the use of materials of preselected densities, for the purpose of manufacturing balls having a low moment of inertia. The instant invention accomplishes this by featuring an inner core having a minimum specific gravity of 0.1063 per pound of ball weight, and a construction wherein the volume ratio of the inner core to that of the encapsulating mass, in conjunction with the specific gravity ratio of the inner core to that of the encapsulating mass, yields a maximum moment of inertia (about the ball's vertical axis) of 0.318 in-ozs-sec.sup.2 per pound of ball weight. As the moment of inertia of a fixed weight ball is decreased, the translational kinetic energy increases and the rotational kinetic energy decreases. However, since the translational kinetic energy increases at a greater rate than the rate at which the rotational kinetic energy decreases, the resulting effect is an increase in total kinetic energy output. An additional increase in total kinetic energy output is obtained through use of a high density top weight mass concentrated closely around the ball's inner core, with its lower surface positioned at the midplane of the ball.