Claims:
What is claimed is
1. A game ball adapted for rolling on a hard surface in a manner similar to that of a hard Bocce ball rolling on a lawn-like yielding surface, comprising a soft, resilient polymeric shell having spherical exterior and interior surfaces, a quantity of fine, dry, granular solid in said shell, said solid being shiftable along said spherical interior surface as said game ball is rolled and having an apparent volume from about 40 percent to about 70 percent of the internal volume of said shell, said shell being sufficiently inflexible to permit said game ball to be rolled substantial distances on a hard surface and sufficiently flexible to have portions thereof deflected during rolling contact with a hard surface, the kinetic energy of rolling being dissipated in friction between said granules and in said flexing of said shell, whereby said game ball is slowed and brought to a stop in a relatively short distance on a hard surface.
2. A game ball as defined in claim 1 wherein the outer diameter of said shell is approximately 3 3/8 inches and the thickness of said shell is from 0.050 to 0.080 inches, wherein the apparent volume of said granular solid is about 50 percent of the internal volume of said shell and wherein the weight of said game ball is about 12 ounces.
3. The game ball as defined in claim 2, wherein said fine, dry, granular solid is ordinary beach sand.
Description:
BACKGROUND OF THE INVENTION
The game of Bocce is conventionally played on a yielding surface such as a lawn or a clay court, and consequently is not suitable for indoor play. Attempts have been made to provide a ball which will be suitable for use on a hard surface, whether indoors or outdoors but such attempts have not been completely satisfactory. For instance, a hollow ball containing a viscous fluid was tried, but, as would be expected, at relatively high rolling rates, the fluid would tend to cling to the internal surface and would ride "over the top". However, as the ball would slow down the fluid would no longer ride over the top and the drag would suddenly increase. In another variation a solid material was secured to one portion of the interior wall and the ball was provided with a flat spot on the exterior at the same location. Obviously, such a ball would roll very irregularly.
SUMMARY OF THE INVENTION
A ball in accordance with the present invention has a spherical, resilient outer shell, the shell being sufficiently flexible to deform substantially as the ball rolls. The shell is preferably made of a polymeric material. The shell contains a fine, dry, granular solid, the granular solid having an apparent volume ranging from about 40 percent to about 70 percent of the internal volume of the shell.
Accordingly, an object of the present invention is to provide a soft ball which can be rolled on a hard surface and which will simulate the roll of a hard Bocce ball on a yielding surface.
Another object of the invention is to provide a ball with which the game of Bocce can be played on a hard surface without marring said surface.
A further object of the invention is to provide a ball with a controlled extent of drag which can be matched to the space available for play.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWING
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing, in which:
The single FIGURE shows in cross section a ball in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A ball in accordance with the present invention is shown in the FIGURE where spherical, resilient outer shell 1 contains a quantity of fine, dry, granular solid 2. The shell is preferably made of polyvinyl chloride but can also be made of rubber or any other polymeric material which is resilient and soft enough so that the shell will deform as it rolls over a hard surface. Deforming of the shell during rolling ensures that the ball will not mar the hard surface over which it rolls and furthermore ensures that kinetic energy of rolling will be dissipated during the flexing operation. Since a softer ball will deform to a greater extent than one which is less soft, energy will be dissipated more rapidly, and therefore a softer ball will more quickly come to a stop. Advantage can be taken of this property to match the ball to the playing area available.
A suitable diameter for a ball in accordance with the present invention is about 3 3/8 inches and a suitable wall thickness is from about 0.050 inches to about 0.080 inches.
Although almost any dry, granular material is suitable for the internal component, ordinary beach sand, well-dried, is preferred due to its low cost and availability. The quantity used is somewhat critical in that an apparent volume amounting to one-third that of the interior of the ball will produce an erratic roll whereas a quantity amounting to three-fourths of the interior volume of the ball causes the ball to roll too far and makes the ball unnecessarily heavy. If the ball is completely full it behaves almost like a solid ball and rolls much too far. This point is significant since it indicates that most of the drag results from shifting of the granules rather than flexing of the shell. Nevertheless, even when the ball is almost completely full of granular solid, the roll of the ball is shorter that that of a hard ball so that a substantial portion of the drag must be contributed by flexing of the shell.
Further examples of materials of which the shell may be composed are poly E.V.A. and Kraton.
As indicated above, the distance which the ball will travel on a hard surface for the same initial velocity is a function of the quantity of granular material contained therein. It has been found that a quantity of granular material having an apparent volume equal to half that of the interior of the ball is particularly suitable. It should be noted that the term "apparent volume" is used to indicate the volume which would be measured by pouring the granular material into a graduated cylinder and not the volume which would be measured by displacement of a liquid.
A ball made in accordance with the present invention is sufficiently heavy so that it is immune to the effect even of heavy winds so that such a ball can be used in the game of Bocce even under adverse weather conditions. On the other hand, it is not so heavy that it would be dangerous for use by children, the flexibility of the shell constituting another safeguard against injury.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above article without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.