Energy Absorbing Ball

Abstract

An energy absorbing ball has a spherical resilient shell having a smooth inner surface and a smooth outer surface. A fill material is introduced into the shell via a fill opening in the shell. The fill material includes a liquid and a solid particulate having a density greater than the liquid, and with the fill material substantially entirely filling the shell. A plug in the fill opening seals the fill material within the shell, optionally with a recess over the plug. The smooth inside and outside surfaces of the she are spherical and free of any projections or obstructions.

Description

BACKGROUND OF THE INVENTION

[0001] The invention relates to an energy absorbing ball, and more specifically to an energy absorbing weighted ball for practicing ball throwing, catching and hitting.

[0002] Many energy absorbing balls have been proposed with varying uses, such as lawn bowling, street hockey, indoor games, baseball training, etc. Generally these types of energy absorbing balls have an impact resistant resilient rubber or plastic shell containing a filler material that may include solid particles, bulk weights, liquids and/or gases. The filer material is typically provided to absorb and distribute impact forces on the ball, or to increase rolling and rebounding resistance. Although several of these designs have achieved varying degrees of success, engineering challenges remain to providing a still further improved energy absorbing ball.

SUMMARY OF THE INVENTION

[0003] An energy absorbing ball has a spherical resilient shell having a smooth inner surface and a smooth outer surface. A fill material s introduced into the shell via a fill opening in the shell. The fill material includes a liquid and a solid particulate having a density greater than the liquid, and with the fill material substantially entirely filing the shell. A plug in the fill opening seals the fill material within the shell, optionally with a recess over the plug. The smooth inside and outside surfaces of the shell are spherical and free of any projections or obstructions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a perspective view of a weighted ball.

[0005] FIG. 2 is a section view of the ball shown in FIG. 1.

[0006] FIG. 3 is an exploded perspective view of the ball shown in FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

[0007] As shown in FIGS. 1-3, a weighted energy absorbing ball 10 has a resilient plastic or rubber spherical shell 10 containing a fill material 16. The shell has a smooth inside surface 14 and a smooth outside surface 12, and a wall thickness generally of about 2-5 millimeters. The ball diameter is 5-15 or 6-8 cm. The shell 10 may be formed by joining to molded hemispherical half spheres together, The smooth inside surface 12 is free of any projections or obstructions, other than manufacturing artifacts.

[0008] A fill opening 18 may be molded into or otherwise provided in the ball, to allow for filling the ball with the fill material. After the ball is filled, a plug 20 may be permanently installed into the fill opening 18 using known techniques, such as pressing the plug into the fill opening and using bonding or adhesive materials. The outside surface 12 of the ball 10 is smooth and continuous, except at the fill opening 18, where the top of the plug 20 may not be flush with the surrounding spherical surface, and potentially with a slight annular gap (e.g., 0.1 mm) between the plug 20 and the surrounding spherical surface, leaving a recess 22 over the fill opening. As the plug 20 completely and permanently seals the shell, no additional sealing materials or devices are needed.

[0009] The fill material is a mixture of a liquid, such a light oil, and a particulate such as iron sand. In some embodiments, the oil may be replaced with salt water or an anti-freeze liquid, to prevent the fill material from freezing in cold conditions. The liquid and the particulate are selected so that they do not react with each other, and so that the particulate does not dissolve or clump up. The particulate may alternatively comprise iron filings, sand or other particulate such as metal or glass beads.

[0010] The particulate is heavier than the liquid. With the ball at rest, the particulate sinks to the bottom, with the liquid displaced above the particulate. The total weight of the ball including the shell and the fill material generally ranges from about 275 to 575 grams, more typically about 375 to 475 grams. The particulate forms the bulk of the fill material, generally making up 50 or 60 to 90 or 95% of the weight of the fill material, with the balance being the liquid. The ratio of particulate to liquid will vary depending on the liquid and particulate selected, the size and weight of the ball, and other factors.

[0011] The fill material substantially entirely fills the shell 10, with no significant air space remaining in the shell after it is filled. The fill material, which is largely incompressible, helps the ball to maintain its spherical shape when subjected to impact forces, in contrast to balls containing air, which is compressible. Correspondingly, the ball 10 does not require an air fill port and may therefore be permanently sealed after manufacture at the factory. The shell may contain positive pressure if the fill material is injected and sealed under positive pressure conditions.

[0012] In use, as the ball 10 impacts against a surface such as a wall, a bat or the ground, the impact force is distributed within the ball via the fill material. As the density of the particulate is greater than the liquid, the particulate tends to at least initially be at the bottom of the ball 10. The center of gravity of the ball 10 is then below the equator. As a result, the ball may roll with an eccentric movement, although rolling is minimal due to the damping effect of the fill material. Correspondingly, if the ball is agitated to temporarily more evenly distribute the particulate within the liquid, the ball will roll further with less eccentric movement.

[0013] As the shell is resilient, the ball 10 is deformable using nominal hand force. The ball 10 may also be used as a hand-held exercise ball. As used here, substantially no air or gas means less than 1, 2, 3, 4 or 5% of the volume of the ball, and substantially filling the ball means filling 95% or more of the volume of the ball,

[0014] Thus, a novel ball has been shown and described. Various changes and substitutions may of course be made without departing from the spirit and scope of the invention. The invention, therefore, should not be limited except by the following claims and their equivalents.

Claims

1. An energy absorbing ball, comprising: a spherical resilient shell having a smooth inner surface and a smooth outer surface; a hollow fill stem projecting radially inward from the smooth inner surface, the hollow fill stem having a fill opening extending from the smooth outer surface to an interior cavity of the spherical resilient shell; a fill material within the interior cavity, the fill material comprising a liquid and a solid particulate having a density greater than the liquid, and with the fill material substantially entirely filling the shell; and a plug in the hollow fill stem and obstructing the fill opening to seal the fill material within the interior cavity, wherein the plug is disposed below the smooth outer surface such that an empty recess is formed below the smooth outer surface to a top portion of the plug.

2. The ball of claim 1 with the fill material sealed within the shell only by the plug.

3. The ball of claim 1 with the ball containing substantially no air or gas.

4. The ball of claim 1 with the shell having a uniform wall thickness generally of about 2-4 millimeters.

5. The ball of claim 4 with the shell having an outer diameter of 6-8 cm.

6. The ball of claim 5 with the smooth inner surface of the shell free of any projections or obstructions other than the hollow fill stem.

7. The ball of claim 6 with the liquid comprising oil and the particulate comprising iron sand.

8. The ball of claim 6 with the particulate comprising metal filings, sand, metal beads or glass beads.

9. The ball of claim 8 with the ball weighing 375 to 475 grams.

10. The ball of claim 1, wherein: the spherical resilient shell is formed of rubber or plastic, the shell having a uniform wall thickness of 2-4 millimeters and an outer diameter of 6-8 cm; the hollow fill stem is molded into the shell; and the liquid of the fill material is oil and the particulate of the fill material has a density greater than the oil.

11. The ball of claim 10 with the smooth inner surface of the shell free of any projections or obstructions other than the hollow fill stem.

12. The ball of claim 11 with the ball weighing 375 to 475 grams.

13. The ball of claim 11 with the particulate comprising 60 to 90% by weight of the fill material.

14. The ball of claim 1, wherein no sealing material is disposed on the plug.