Abstract: A bowling ball according to one embodiment of the present invention has a hollow member (16), or a member of less specific gravity than the mass of the bowling ball, disposed therein with its centroid displaced from the geometric center of the ball. The lighter weight member in the ball permits the use of a dense polymerizable composition for the basic mass of the ball. The ball is molded without the usual shell so that it has a resilient striking surface for maximum impact and pin carry. In another embodiment, a member (46) of a higher specific gravity than that of the polymerizable mass is added generally on the same axis as the lighter weight member (42) to increase the eccentricity of the ball and give it even more driving power upon impact with the pins.

Abstract: A bowling ball according to one embodiment of the present invention has a hollow member, or a member of less specific gravity than the mass of the bowling ball, disposed therein with its centroid displaced from the geometric center of the ball. The lighter weight member in the ball permits the use of a dense polymerizable composition for the basic mass of the ball. The ball is molded without the usual shell so that it has a resilient striking surface for maximum impact and pin carry. In another embodiment, a member of a higher specific gravity than that of the polymerizable mass is added generally on the same axis as the lighter weight member to increase the eccentricity of the ball and give it even more driving power upon impact with the pins. The member of higher specific gravity may be provided with pin members extending therefrom to the surface of the ball.