Sewn ball and manufacturing method thereof

Abstract

A sewn ball includes an inner tube and a housing. The inner tube includes a tube body, a yarn layer and a rubber layer, wherein the yarn layer is attached to an external surface of the tube body, the rubber layer is attached to an external surface of the yarn layer and is then vulcanized, in such a manner that a rubber raw material of the rubber layer permeates through yarn gaps of the yarn layer, so as to integrate the tube body, the yarn layer with the rubber layer. The housing wraps around and is attached to the inner tube. The sewn ball provided by the present invention has excellent jumping ability, high strength, good durability, small circumferential error, and excellent balance and flight stability.

Description

CROSS REFERENCE OF RELATED APPLICATION[0001]The present invention claims priority under 35 U.S.C. 119(a-d) to CN 201610156079.6, filed Mar. 18, 2016.BACKGROUND OF THE PRESENT INVENTION[0002]1. Field of Invention[0003]The present invention relates to a technical field of sports goods, and more particularly to a sewn ball and a manufacturing method thereof.[0004]2. Description of Related Arts[0005]The inner tube of conventional sewn balls, such as sewn footballs and sewn volleyballs, includes three structural forms as follows: (1) rubber inner tube; (2) yarn tire by winding a layer of yarn around the exterior of the rubber inner tube; and (3) cloth tire by attaching a layer of cloth to the exterior of the rubber inner tube. Shortcomings of the above three structural forms are respectively described as below.[0006]Shortcomings of the first structure are: firstly, due to the flexibility, the rubber inner tube is able to expand unlimitedly without forming while being injected with the ga...

AI Technical Summary

Benefits of technology

The present invention provides a sewn ball with excellent jumping ability, high strength, good durability, small circumferential error, and excellent balance and flight stability. The yarn layer is wound around the external surface of the tube body, and the rubber layer is attached to the external surface of the yarn layer. The thickness of the yarn layer is properly selected to improve the strength of the inner tube, and the rubber layer allows the ball to have smooth surface softness and reduced circumferential error, thereby improving the rebound ability of the ball. The balance plate is located at a position symmetrical to the gas nozzle on the inner tube for ensuring the ball has excellent balance and flight stability. A double layer tube body consisting of an internal layer body and an external layer body tightly attached to the internal layer body is provided to prevent leakage and improve the service life of the ball. The rubber layer further adopts sandwiching the yarn reinforcement layer between the internal layer rubber and the external layer rubber to enhance the impact resistance and resilience strength of the ball, ensuring a long-term and reliable performance.

Problems solved by technology

Shortcomings of the first structure are: firstly, due to the flexibility, the rubber inner tube is able to expand unlimitedly without forming while being injected with the gas, and the expanding force is directly applied to the housing, so that the housing easily bursts to expose seaming lines till the ball finally bursts; secondly, the rubber inner tube has poor gas tightness, after a long period, the sufficient gas gradually slowly leaks, so that the gas always needs to be added, thereby it is not convenient for usage; thirdly, the gas nozzle of the rubber inner tube is located at one side thereof, the gas nozzle and a circle of the yarn reinforcement layer, which is around the gas nozzle and attached to the rubber inner tube, allow the center of gravity of the whole ball to trend to the side where the gas nozzle is located, so that the center of gravity of the ball is unbalanced, which leads to the unstable flight.

However, after the yarn tire is injected with the gas, the whole ball is hard and easily hits hands.

Simultaneously, once the whole ball is hard, the flight balance becomes poor when the ball flies.

Accordingly, the hard ball not only has poor rebound, but also results in poor sense control force of the player.

Furthermore, during the manufacturing process of the yarn tire, the yarn is mechanically wound around the rubber inner tube, and however, the mechanical wound yarn tire is unable to ensure the circumferential error of the ball, the circumferential error generally reaches 3-5 mm, which leads to poor balance and jumping ability, and unstable flight of the ball.

However, the cloth tire, obtained by replacing the yarn with the cloth, has poor forming, low striking breaking strength of the ball, and large circumferential error (in generally, which reaches 3-5 mm), so that it has poor jumping ability, poor balance, unstable flight, insufficiently strength and poor durability.

Therefore, the rubber inner tube is able to continuously expand with the increase of the internal gas, so that it is unable to control the ball to achieve the determined shape and size, thus the gas leakage easily appears.

In spite that the yarn tire is able to avoid a burst during tire inflation and plays a role in forming, due to the ball is mechanically wound with yarns, the yarns are always unevenly wound, so that the ball is unable to be completely controlled to achieve the determined shape.

Similarly, in spite that the cloth tire is able to play a role in forming, the cloth has various latitude and longitude lines, which leads to uneven tensions, so that it is unable to completely control the ball to achieve the determined shape.

More attaching or sewing actions are, and lower productive efficiency is.

Furthermore, the attaching or sewing is large in difficulties and low in accuracy, so that the manufactured ball is bad in hand feeling and the circumferential error is unable to be ensured.

In spite that the Chinese patent reduces the amount and the difficulty of the attaching or sewing, and increases the accuracy thereof, during the cutting the leather pieces, the four-leather-units and the three-leather-units are large in length, so that the raw materials are wasted.

Therefore, once this football is produced on a large scale, the raw materials are greatly and the input cost of the raw materials is increased.

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