2. Description of the Prior Art Pitching machines and ball-throwing machines are well-known in the art and generally fall into four categories: (1) machines that employ a spring actuated arm mechanism to propel the ball; (2) machines that employ at least one rotating wheel or a pair of rotating, coacting wheels to propel the ball; (3) machines that rely on pneumatic pressure to propel the ball; and (4) machines that employ converging and diverging rotatable discs to propel the ball.

Examples of ball-throwing machines that employ a spring mechanism to propel the ball are described, for example, in U. S. Patent No. 3,757,759 which issued on September 11, 1973 to J. G. Haworth for Automatically Varied Oscillation Type Ball Projecting Device and U. S. Patent No. 4,524,749 which issued on June 25,1985 to Paul S. Giovagnoli for Spring- Type Ball Pitching Machine. Commercial versions of such a machine have been marketed by Master Pitching Machine of Kansas City, MO.

In recent years, the majority of the commercially available ball-throwing or pitching machines employ one or two coacting rotating wheels which are used to propel a ball that is introduced into the nip between the rotating wheels or between a plate and a single rotating wheel. Examples of such machines are described in U. S. Patent No. 3,724,437 which issued on April 3,1973 to E. W. Halstead for Ball-throwing Machine; U. S. Patent No. 3,815,567 which issued on June 11,1974 to Norman S. Serra for Coacting Wheel Ball Projecting Device; U. S. Patent No. 4,197,827 which issued to Tommy L. Smith on April 15,1980 for Coacting Wheel Ball Projecting Device; U. S. Patent No. 4,423,717 which issued to Edward W. Kahelin on January 3,1984 for Variable Double Wheel Ball Propelling Machine; U. S.

Patent No. 4,583,514 which issued to Fujio Nozato on April 22,1986 for a Ball-throwing Machine; and U. S. Patent No. 4,922,885 which issued to Shigery Iwabuchi et al. on May 8, 1990 for a Pitching Machine. Commercial machines that employ a pair of rotating coacting wheels are marketed by The Jugs Company of Tualatin, Oregon, ATEC of Sparks, Nevada, AAI American Athletic, Inc. of Jefferson, Iowa, K-Lin Specialties, Inc. of Huntington Beach, California and OMNI Sports Technologies of Kansas City, MO.

A problem with such ball-throwing machines, particularly those which utilize coacting wheels, is that regulation baseballs often cannot be used, for a variety reasons.

Primary among such reasons is that the stitching on the surface of the ball interferes with the driving means such that the balls are not accurately thrown. Accordingly, specially-designed balls have been designed for use with such ball-throwing machines. For example, U. S. Patent No. 4,256,304, which issued to Smith, et al. on March 17,1981 for a"Baseball"discloses a baseball suitable for continuous use in a pitching machine comprising a molded, resilient polyurethane foam sphere having a smooth polyurethane surface skin, with the surface of the

sphere being provided with a regular pattern comprising a multiplicity of cup-like or hemispherical depressions substantially covering the surface.

However, these specially designed balls do not accurately simulate regulation baseballs in that there is no stitching by which a batter may determine the angular rotation of the ball.

SUMMARY OF THE INVENTION Against the foregoing background, it is a primary object of the present invention to provide an improved ball for use in a pitching machine that includes a stitching pattern for a batter to determine the angular rotation of the ball in flight.

It is another object of the present invention to provide such a ball that is durable so as to withstand the continued, high-stress use in a pitching machine and being struck by a bat.

It is yet another object of the present invention to provide such a ball that physically resembles a regulation baseball in size and weight, as well as appearance.

It is still another object of the present invention to provide such a ball that is inexpensive to manufacture.

It is another object of the present invention to provide such a ball that induces turbulent airflow over the surface thereof so as to reduce drag and increase accuracy.

To the accomplishments of the foregoing objects and advantages, the present invention, in brief summary, comprises a ball for use with a pitching machine, said ball having a smooth surface in which a plurality of indentations or dimples are regularly spaced.

The inner surfaces of one or more of these indentations is colored with a dye or paint such that the rotational velocity of the baseball may be determined when the ball is in flight. The colored indentations are patterned so as to simulate the stitching on a regulation baseball. In a particularly preferred embodiment, a plurality of recessed slots are provided to simulate the stitch pattern of an actual baseball, and the inner portion of such recessed slots are colored with a paint or dye to provide a visual impression of stitching.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and still other objects and advantages of the present invention will be more apparent from the detailed explanation of the preferred embodiments of the invention in connection with the accompanying drawings, wherein : FIG. 1 is a side elevational view of the ball of the present invention; FIG. 2 is a perspective illustration of an alternative embodiment of the ball of the present invention showing an alternative indentation design and pattern; FIG. 3 is a cross-sectional view of the ball of FIG. 1 taken through the center thereof ; and FIG. 4 is a side elevational view of the ball of FIG. 2 showing the pattern of colored indentations.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings and, in particular, to Figs. 1 and 2 thereof, the ball of the present invention is provided and is referred to generally by reference numeral 10. In the preferred embodiment, the ball 10 is composed of a urethane foam having a uniform density throughout its cross-section. The ball 10 is spherical, having a diameter of approximately 2 7/8 inches (+/-0.01 inch) and having a maximum hardness of between about 50 and 100 on the type A-2 Shore durometer scale and preferably between about 70 and 80 on the A-2 Shore durometer scale. The weight of ball 10 is between 4.5 and 5.0 ounces, preferably approximately 5.0 ounces. Strict compliance with these measurements is required so as to accurately reproduce the dimensions, weight and hardness of a regulation baseball.

The ball 10 has a smooth outer surface 12 in which a plurality of depressions or "dimples"14 are provided in a regular pattern. The majority of these depressions 14 are semi-spherical in shape, having a diameter of between 0.10 and 0.18 inches, and a radius of between 0.05 and 0.10 inches. In the preferred embodiment, these depressions are 0.10 inches wide, 0.08 inches deep, and having a radius of 0.08 inches.

The depressions 14 cover the entire surface 12 of ball 10 and are organized in rows that run parallel with the equator 16 of the ball 10. The spacing between depressions 14 is between 0. 05 and 0.18 inches. In a regulation size ball 10 there will be approximately 250 to 500 depressions 14.

As with golf balls, these depressions 14 serve to interrupt laminar air flow over the surface of the ball 10 in flight and induce turbulent air flow. The result of this induced turbulence is reduced drag on the ball 10, which allows the ball 10 to travel farther and with greater accuracy.

In the preferred embodiment, a number of depressions 14 take the form of recessed slots 18 which are disposed in a pattern so as to simulate the stitching of a regulation baseball. The use of slots 18 more accurately recreates the shape of the stitching in a regulation baseball. However, it should be appreciated that the entire surface of the ball 10 may be covered with uniform semi-spherical depressions 14. In the preferred embodiment, these slots would be 0.375 inches long by 0. 10 inches wide by 0.05 inches deep, and have a radius at the ends of 0.05 inches. The spacing between slots 18 is between 0.10 and 0.20 inches, and in the preferred embodiment there are 118 slots 18 covering the surface of the ball 10 in the regulation ball stitching pattern.

Disposed within the slots 18, or, alternatively, within one or more of the indentations 14, is coloration or paint 20 such that the rotational velocity of the ball 10 may be determined when ball 10 is in flight by observing the movement and rotation of slots 18 or those indentations 14 containing paint 20. As indicated, in the preferred embodiment, the slots 18 are patterned so as to simulate the stitching on a regulation baseball. Alternatively, the indentations 14 containing paint 20 may similarly be arranged so as to simulate the baseball's stitching pattern. The color of such paint 20 in such embodiment would be red, so as to simulate the red threads in the stitching.

It should be appreciated that paint 20 should be situated at the base of slots 18 or indentations 14 and should not reach the surface 12 of ball 10. If paint 20 were to reach the surface 12 of ball 10, the paint 20 would disrupt the smooth surface 12 of the ball 10, thereby potentially interfering with the drive mechanism of a pitching machine, or even rub off on such drive mechanism.

Having thus described the invention with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications can be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.