Bowling ball insert
 An insert system for the finger and thumb holes of a bowling ball and a method for installing the insert system. The insert system includes a master that is bonded inside each of the holes. A number of inserts are provided having different internal diameters, shapes, and pitches (the angle of the hole relative to the ball's surface). Inserts are also provided that have offset internal holes, to allow for changes in finger span by rotating the insert relative to the master. The master is provided with tapered inner and outer surfaces. The taper on the outer surface helps in bonding the master to the ball by providing voids that are filled with adhesive. The tapered inner surface cooperates with a tapered outer surface on the insert, to lock the insert to the master. A round head screw assembly is additionally provided with each insert to insure that a shock of impact will not loosen the fit between the master and the insert. 
A
A63B
inventional
James R.
Hill