Foamed inner tube

Description

BACKGROUND OF THE INVENTION

(a) Technical Field of the Invention

The present invention is related to a foamed inner tube, and more particularly, to one used for balls that gives strong structure, long service life and excellent resilience.

(b) Description of the Prior Art

The ball bladder is usually related to a direct type of an inner tube as illustrated in FIG. 1 of the accompanying drawings, an inner tube 1 having its surface entwined with yarns 11 as illustrated in FIG. 2; a yarn 11 entwined inner tube 1 being further wrapped with an outer tube 12 as illustrated in FIG. 3; or an inner tube 1 bound with fabrics 13 as illustrated in FIG. 4. However, these ball bladders are found with the following flaws:

• 1. As the direct type of inner tube is molded and admixed with sulfur, it tends to continuously expand along with the addition of air.
• 2. The inner tube entwined with yarns involves more complicated manufacturing process.
• 3. The sandwich type inner tube also involves complicated manufacturing process and higher production cost.
• 4. The fabric bound inner tube also involves comparatively higher production cost.

Even though the yam entwined inner tube, the sandwich type inner tube or the fabric bound inner tube is free of the problem of continuous expansion when inflated, its impact force and resilience are still limited and fails to provide longer service life.

SUMMARY OF THE INVENTION

The primary purpose of the present invention is to provide a ball inner tube that allows easier process and longer service life. To achieve the purpose, the material for the ball inner tube is first given a primary heating process and bound with a material blended with the same material used for making the inner tube and an additive of foaming agent before going through a secondary heating process for the foaming agent to be integrated with the inner tube to become the final product of a foamed inner tube as a ball bladder.

The amount of the foaming agent to be added is adjustable depending on the thickness and resilience as required for the particular ball inner tube; and the foaming agent can be prepared in any color for the finished product of the ball.

Other than rubber, TPU, PVC and other material identical with that used for the inner tube may be blended with the foaming agent for the manufacturing of the foamed inner tube.

The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a construction of a direct type of inner tube.

FIG. 2 is a schematic view showing a construction of a yarn-entwined type of inner tube.

FIG. 3 is a schematic view showing a construction of a sandwich type of inner tube.

FIG. 4 is a schematic view showing a construction of a fabric bound type of inner tube.

FIG. 5 is a process flow chart of the present invention.

FIG. 6 is a schematic view showing a construction of the present invention.

FIG. 7 is a table showing results of impact test conducted on the present invention and the prior art.

FIG. 8 is a table showing impact test data conducted on the present invention and the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

Referring to FIGS. 5 and 6, an inner tube of the present invention is made by first having a material designated for the inner tube to go through a primary heating process; and then the inner tube 1 is bound with a mixture of a foaming agent and the same material designated for the inner tube to be put through a secondary heating process at a temperature of 165° C. to become a formed inner tube serving as a ball bladder. Wherein, the inner tube 1 for being contained by the foamed layer 2 is prevented from continuously expanding when inflated to achieve the same effects provided by the yarn entwined, fabric bound or sandwich type of the prior art while the foamed layer 2 allows adjustment of its thickness and resilience depending on the requirements of the particular ball to improve its hand-touch comfort and resilience.

The inner tube of the present invention also provides multiple functions. The foamed layer 2 can be made into any color as desired to forthwith become a finished product of a ball for direct sales.

Either in impact withstanding or in resilience, the inner tube of the present invention outperforms and inner tube of the prior art. As shown in FIG. 7, after the impact test of 5000 rounds, the present invention maintains its amount of deformation not greater than 3 mm in X, Y and Z axes to ensure of its true circle. In 200 cm drop test, the present invention gives a bouncing height not less than 140 cm and the bouncing could last 15˜20 rounds until it ends up in still.

As illustrated in FIG. 8 for further examination into the detailed data availed form the impact test based on X, Y and Z axes of a circle, after 5000 rounds of impact, the variance of any of the prior art ranges between 4.0˜7.0 mm; and the present invention, 3.0 mm in the distribution of 698 m, 697 mm, and 700 mm respectively for X, Y and Z axes.

Advantages of the present invention include but not limit to the followings:

• 1. Resilience of the foamed layer gives hand-touch comfort and protection;
• 2. Reduced the inner pressure the outer layer of the ball as confined by the foamed layer help ease off the pressure acting upon the stitches made either by a sewing machine or by hand on the outer layer for longer service life;
• 3. Increased impact withstanding and resilience performance for the ball, and the foaming multiplex can be adjusted for the resilience of the ball depending on the appearance of the ball or customer's needs; and
• 4. Whereas the manufacturing process is similar to that for the yarn-entwined type or fabric bound type, purchase of yarn-entwining or fabric-binding machine is not required for cost saving.

Furthermore, the additional foamed layer of the present invention for the ball bladder increases the airtight performance of the inner tube to reduce air leakage, natural deflation rate, and chances of being pierced through by sharp objects including rocks and nails.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.