Polyurethane ball for games and sports

Abstract

A polyurethane ball for games and sports includes a core portion made of relatively heavy and low-cost materials and in the shape of a regular spherical body, and an outer portion made of a polyurethane material and having a predetermined thickness to enclose the entire core portion. The ball is manufactured by way of centering a pre-molded core portion in a mold and filling the mold with the polyurethane material to produce an integral ball. The materials for the core portion include rubber or foamed rubber, plastics or foamed plastics, or recycled wood materials. A heavy-weight filler, such as powdered calcium carbonate, may be blended into the materials for the core portion, so as to effectively control an overall weight of the polyurethane ball.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a polyurethane ball for games and sports, and more particularly to a ball having a core portion made of relatively weight and low-cost materials, and an outer portion made of a polyurethane material and having a predetermined thickness to enclose the core portion. The ball is formed by centering the core portion, which is separately molded first, in a mold and filling the mold with a polyurethane material, so that the ball has desired weight and elasticity without increasing the amount of polyurethane material that is expensive.

[0002] Polyurethane (PU) balls are available in various sizes from as small as a baseball to a ball as large as 8 inches in diameter, so as to meet different demands in the markets and be used in different games and sports. There are times when a polyurethane ball preferably has an increased weight. A conventional way to increase the weight of the polyurethane ball is to lower the foaming power of the polyurethane material used to form the ball. However, this will relatively increase the amount of polyurethane material in forming the ball, particularly in the case of the 8-inch ball. Since the polyurethane material is three or four times as expensive as other plastic materials, such as polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC), increased amount of polyurethane material will largely increase the manufacturing cost of the polyurethane ball. This fact inevitably prevents the weight-increased polyurethane balls from being widely accepted in the markets and brings troubles to the manufacturers in selling the same.

[0003] It is therefore desirable to develop a polyurethane ball that eliminates the above-mentioned drawbacks.

SUMMARY OF THE INVENTION

[0004] A primary object of the present invention is to provide a polyurethane ball that has a core portion made of relatively weight and low-cost materials, and an outer portion made of a polyurethane material and having a predetermined thickness to enclose the core portion. The ball is formed by means of centering a pre-molded core portion in a mold and filling the mold with a polyurethane material, so that the ball may have desired weight and elasticity without increasing the amount of polyurethane material that is expensive.

[0005] Another object of the present invention is to provide a polyurethane ball for games and sports having an integrally molded outer portion enclosing a core portion that is separately molded with low-cost materials, such as rubber or foamed rubber, plastics or foamed plastics, or recycled wood materials. A heavy-weight filler, such as powdered calcium carbonate, may be added into the materials for forming the core portion, so as to effectively control the final molded weight of the polyurethane ball.

[0006] A further object of the present invention is to provide a polyurethane ball for games and sports having a core portion enclosed in a layer of polyurethane material, on an outer surface of which differently colored or patterned decorative areas or a plurality of raised small dots are provided through molding to create good appearance and hand feeling.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

[0008] FIG. 1 is a perspective view of a polyurethane ball for games and sports according to the present invention, wherein a part of the outer portion of the ball is cut away to show an internal structure thereof;

[0009] FIG. 2 is a perspective view of an embodiment of the present invention;

[0010] FIG. 3 is a perspective view of another embodiment of the present invention; and

[0011] FIG. 4 is a sectioned side view showing the forming of the present invention in a mold.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Please refer to FIG. 1. The present invention relates to a polyurethane ball 1 for games and sports. The ball 1 mainly includes a core portion 10 and an outer portion 20. The outer portion 20 is molded from a polyurethane material, while the core portion 10 maybe made of rubber or foamed rubber, various types of plastic materials or foamed plastic materials, or recycled wood materials, that all are low-cost materials, to have a properly controlled net weight. An adequate amount of heavy-weight filler, such as powdered calcium carbonate (CaCO3), may be added and blended into the materials of the core portion 10 to effectively control a final weight of the molded core portion 10, and accordingly, of the whole polyurethane ball 1.

[0013] The core portion 10 is a separately molded regular spherical body, a diameter and a net weight of which are determined depending on actual usages or manufacturers' specifications. Taking a polyurethane ball 1 having a diameter of 8 inches (8″) as an example, there are usually two specifications available, namely, 5-pound (lb) and 2.5-pound (lb) balls. There are multiple combinations of diameter of core portion 10 and thickness of outer portion 20 available for users. It is most preferable the outer portion 20 has a thickness as small as possible to decrease the amount of polyurethane material used to make the ball 1 and therefore reduce the manufacturing cost thereof. The outer portion 20 may have a thickness within the range from 5 mm to 20 mm or more. Generally, an outer portion 20 of 5 mm is thick enough to provide desired surface texture and sufficient elasticity.

[0014] FIG. 2 shows a first embodiment of the polyurethane ball 1 of the present invention. In this first embodiment, the ball 1 is formed on an outer surface of the outer portion 20 with differently colored or patterned decorative areas 21. This can be achieved through mold design. And, FIG. 3 shows a second embodiment of the polyurethane ball 1 that has a plurality of raised small dots 22 evenly distributed over an outer surface of the outer portion 20 to create changes in the appearance of the ball 1 as well as a different hand feeling. Such changes in the appearance of the polyurethane ball 1 enable the ball 1 to meet different demands in the markets.

[0015] The polyurethane ball 1 is produced by way of molding. FIG. 4 is a sectioned side view of a mold 30 for forming the ball 1. The core portion 10 in the form of a regular spherical body is separately molded first and then disposed at a center of the mold 30. Thereafter, the polyurethane material is filled into the mold 30, so that the core portion 10 and the polyurethane material together form an integral unit. Since the core portion 10 is initially a separately molded spherical body, it basically has a middle parting line 11 formed thereon to facilitate stripping of mold. When the molded core portion 10 is disposed on a locating pin 31 in the mold 30, aligning of the middle parting line 11 on the core portion 10 with a mold joint 32 of the mold 30 could ensure accurate centering of the core portion 10 in the mold 30 and accordingly good quality of the molded polyurethane ball 1.

[0016] The present invention has been described with preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention as defined by the appended claims.

Claims

1. A polyurethane ball for games and sports, comprising

a core portion and an outer portion;

said core portion being a regular spherical body separately molded from relatively heavy and low-cost materials; and

said outer portion being made of a polyurethane material and having a predetermined thickness to enclose said core portion therein by centering said core portion in a mold and filling said mold with said polyurethane material to produce an integral unit of said core portion and said outer portion.

2. The polyurethane ball for games and sports as claimed in claim 1, wherein said core portion is made of rubber or foamed rubber material.

3. The polyurethane ball for games and sports as claimed in claim 1, wherein said core portion is made of plastics or foamed plastic material.

4. The polyurethane ball for games and sports as claimed in claim 1, wherein said core portion is made of recycled wood materials.

5. The polyurethane ball for games and sports as claimed in claim 1, wherein said core portion includes a heavy-weight filler added and blended into materials for forming said core portion.

6. The polyurethane ball for games and sports as claimed in claim 5, wherein said heavy-weight filler is powdered calcium carbonate.

7. The polyurethane ball for games and sports as claimed in claim 1, wherein said outer portion has a thickness within the range from 5 mm to 20 mm or more.