Patent Application
20110183790
1. Field of the Invention
In general, the present invention relates to toy balls wherein the ball is filled with a secondary free-flowing material. More particularly, the present invention relates to balls that are filled with liquid, commonly called “water balls” in the toy industry.
2. Prior Art Description
Bouncing toy balls made from an inflated rubber or plastic shell have been in existence for well over a century. Glass globes, often called “snow globes” that are filled with water and glitter have been in existence for at least three centuries. However, it has only been in the past few years that these technologies have been combined by toy manufacturers who have begun to make bounceable toy balls out of clear plastic that are filled with water and glitter.
Opaque toy balls that are filled partially with liquids are produced for many functional reasons. For example, many golf balls have been made with liquid filled cores to provide better resilience. Likewise, street hockey balls have been partially filled with water to impede the ball from rolling. However, such prior art balls use liquid fill for functional reasons not for visual aesthetics.
In recent years, formulations for polyurethane and similar polymers have been developed that enable a bounceable ball with a transparent shell to be created. The shell is strong enough to resist rupturing even if the shell is completely filled with liquid and the ball is repeatedly bounced against a hard surface. In the toy industry, such liquid filled balls have become known as “water balls”.
Since water balls can be made with a transparent shell, water balls are often filled with water that is mixed with dye, glitter, and other particulates and/or colorants. This fill provides the toy ball with the characteristics of a snow globe, wherein a person can view the swirling fill material when the ball is agitated.
Although water balls can bounce, they do have a structural weakness. In order to fill a water ball with water, the shell of the water ball is first molded. A hole is then drilled into the ball. Water, glitter and other fill material is then injected into the ball through the hole. Once the ball is filled, the hole is sealed with a plug and adhesive.
When such a prior art water ball is bounced, the adhesive and plug do not have the same resiliency as the shell of the ball. The hole in the ball concentrates stresses. As the ball is bounced fractures appear in the ball that begin around the hole and plug. Once the shell cracks, the integrity of the ball is compromised. The liquid fill leaks from the ball and/or the shell of the ball breaks apart during a subsequent bounce.
A need therefore exists for a water ball configuration that does not have a fill plug and consequently has a completely uniform shell. In this manner, stress fractures are far less likely to occur in the structure of the ball as the ball is bounced. This need is met by the present invention as described and claimed below.
The present invention is a ball assembly and the corresponding method used to manufacture the ball assembly. The ball assembly has free-flowing material in its core that can be loose particulate matter and/or a fluid. The free-flowing material is confined by an inner shell. The inner shell is clear or translucent enough so that the free-flowing material can be viewed through the material of the inner shell. The inner shell is encapsulated in a much thicker outer shell. The outer shell is made of a high-resiliency polymer, such as a polyurethane-based polymer. The outer shell provides the ball assembly with the ability to bounce. Furthermore, the outer shell is preferably clear or highly translucent so that the free-moving material in the center of the ball assembly can be directly viewed through the structure of the ball assembly.
The material of the outer shell has a lower melting point than does the material of the inner shell. In this manner, the inner shell can be placed inside the outer shell as the outer shell is molded. This creates a flawless outer shell around the inner shell that lacks any fill port or plug. The result is a stronger ball assembly that can last longer without fracturing.
For a better understanding of the present invention, reference is made to the following description of an exemplary embodiment thereof, considered in conjunction with the accompanying drawings, in which:
Although the present invention ball assembly can be embodied in many ways, such as an oblong football, the embodiment illustrated shows the ball structure being configured as a round ball. This embodiment is selected in order to set forth the best mode contemplated for the invention. The illustrated embodiment, however, is merely exemplary and should not be considered a limitation when interpreting the scope of the appended claims.
Referring to
The outer shell 12 is made from two identical hemispherical shell sections 14, 15 that are joined together along a common equatorial seam 16. As will later be explained, the two hemispherical shell sections 14, 15 are preferably heat bonded in a mold to create the ball's outer shell 12.
The outer shell 12 of the ball assembly 10 is hollow. The outer shell 12, therefore, defines an open internal chamber 18. In the shown embodiment, the internal chamber 18 is spherical in shape. However, other shapes can also be utilized. The outer shell 12 has a wall thickness T1 that is at least as thick as ten percent of the total width of the ball assembly 10. Accordingly, the internal chamber 18 can be as large as eighty percent of the ball's diameter.
An inner shell 20 is provided. The inner shell 20 has an external shape that matches the shape of the internal chamber 18 of the outer shell 12. Accordingly, it will be understood that the inner shell 20 can fit within the internal chamber 18 of the outer shell 12.
The inner shell 20 is made from a flexible transparent/translucent plastic polymer having a melting point of preferably at least 50° C. higher than the material of the outer shell 12. A preferred polymer is a butadiene rubber derivative, such as Low cis Butadiebe Rubber (LBR). Such material is resilient, water impermeable, and can be made clear.
The inner shell 20 is filled with a free-flowing fill material 22 to form an inner ball structure 24. Although the free-flowing fill material 22 can be glitter and/or air, it is preferred that the free-flowing fill material 22 be liquid-based. Accordingly, the free-flowing fill material 22 can be water mixed with colorant and glitter or glycerin mixed with free-floating secondary objects.
The inner shell 20 is injected with the fill material 22 in the same manner as a traditional prior art water ball. Consequently, the inner shell 20 has a fill hole 26 sealed with a plug 28.
Since the outer shell 12 of the ball assembly 10 and the inner shell 20 of the inner ball structure 24 are both clear or highly translucent, it will be understood that the fill material 22 can be seen through the structure of the ball assembly 10. The fill material 22 is free-flowing. It will therefore be understood that the fill material 22 will spin and whirl around inside the ball assembly 10 as the ball assembly 10 is shaken, rolled or otherwise manipulated.
The ball assembly 10 is highly resilient and can be bounced against any hard surface. The outer shell 12 provides the ball assembly 10 with the structural integrity it needs to bounce. Since the outer shell 12 is uniform and devoid of a fill hole, the outer shell 12 is far more resistant to damage than prior art water ball shells.
Referring now to
In the secondary mold 30, the two hemispherical shell sections 14, 15 are heat bonded together along a common equatorial seam 16. The heat applied through the secondary mold 30 is enough to melt bond the two hemispherical shell sections 14, 15 together but is insufficient to melt the inner shell 20. The inner ball structure 24, therefore, becomes fully encapsulated within the outer shell 12.
It will be understood that the embodiment of the present invention that is illustrated and described is merely exemplary and that a person skilled in the art can make many variations to that embodiment. For instance, in the shown embodiment, the outer shell 12 is made of two hemispherical sections. The outer shell 12 can also be made from three or more shell sections. Likewise, the outer shell 12 and the inner ball structure 24 need not be spherical. These elements can be oblong or may have any other shape. All such embodiments are intended to be included within the scope of the present invention as defined by the claims.
