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.

What is claimed is: 
     
         1 . A sewn ball, comprising an inner tube and a housing, wherein the inner tube comprises a tube body, a yarn layer and a rubber layer; 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. 
     
     
         2 . The sewn ball, as recited in  claim 1 , wherein the sewn ball is a sewn football or a sewn volleyball. 
     
     
         3 . The sewn ball, as recited in  claim 1 , wherein a balance plate is provided on the inner tube and located at a position where is coaxially aligned with a gas nozzle and symmetrical to a spherical center. 
     
     
         4 . The sewn ball, as recited in  claim 1 , wherein a circumferential error of the sewn ball is less than 2 mm, and a thickness of the yarn layer is 0.1-1 mm. 
     
     
         5 . The sewn ball, as recited in  claim 1 , wherein the housing comprises 6-32 leather pieces. 
     
     
         6 . The sewn ball, as recited in  claim 1 , wherein the tube body is a double layer tube body comprising an internal layer body and an external layer body tightly attached to the internal layer body. 
     
     
         7 . The sewn ball, as recited in  claim 1 , wherein the rubber layer is an ordinary rubber layer or a foamed rubber layer; after vulcanization, an external surface of the rubber layer forms a layer of dense rubber membrane. 
     
     
         8 . The sewn ball, as recited in  claim 1 , wherein the rubber layer comprises an internal layer rubber, a yarn reinforcement layer and an external layer rubber, wherein the internal layer rubber is attached to an interior of the yarn layer, the yarn reinforcement layer is attached to an external surface of the internal layer rubber, the external layer rubber is attached to an external surface of the yarn reinforcement layer. 
     
     
         9 . A manufacturing method of a sewn ball, comprising steps of:
 (1) cutting a leather into a plurality of leather pieces with a leather cutter, and then sewing the leather pieces according to a spherical surface leather piece arrangement order to form a housing, and meanwhile, leaving 1-4 edges of the housing as an opening;   (2) preparing an inner tube, comprising:   (2A) preparing a tube body fittingly with a roundness of a ball;   (2B) preparing a yarn ball comprising injecting gas into the tube body, and measuring a periphery thereof, winding yarns around an external surface of the tube body with a yarn winding machine;   (2C) preparing a rubber raw material ball by attaching a rubber raw material to an external surface of the yarn ball; and   (2D) preparing a vulcanizing inner tube comprising steps of: putting the rubber raw material ball prepared by the step (2C) into a vulcanizing mould, communicating a gas injection needle on the vulcanizing mould with a gas nozzle of the rubber raw material ball and pressurizing, heating and vulcanizing with a vulcanizing temperature of 95-160° C., a pressure of 3-10 kg/cm 2  and a vulcanizing time of 4-10 min, permeating the rubber raw material through yarn gaps after vulcanization, and vulcanizing mould unloading for obtaining the inner tube;   (3) coating or not coating a binder on a surface of the inner tube obtained by the step (2);   (4) coating a glue around an air hole of the housing obtained by the step (1) and the gas nozzle of the inner tube obtained by the step (2);   (5) putting the inner tube into the housing from the opening thereof, cementing after corresponding the gas nozzle of the inner tube to the air hole of the housing, and sewing the opening of the housing to prepare a pretreated sewn ball; and   (6) injecting gas into the pretreated sewn ball obtained by the step (5) to form a round ball, putting the round ball into a reshaping mould, pressurizing and reshaping with a pressure of 3-10 kg/cm 2 , a time of 1-8 min, and a mould temperature of 30-70° C. for attaching the housing to the surface of the inner tube, and cleaning a surface of the housing, thereby obtaining the sewn ball, wherein a circumferential error of the sewn ball is less than 2 mm.   
     
     
         10 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein after the rubber raw material ball is prepared in the step (2C), a balance plate is attached to a position where is coaxially aligned with the gas nozzle and symmetrical to a spherical center on the rubber raw material ball, and then the step (2D) is processed. 
     
     
         11 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein the sewn ball comprises an inner tube and a housing, wherein the inner tube comprises a tube body, a yarn layer and a rubber layer; 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. 
     
     
         12 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein the sewn ball is a sewn football or a sewn volleyball. 
     
     
         13 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein a circumferential error of the sewn ball is less than 2 mm, and a thickness of the yarn layer is 0.1-1 mm. 
     
     
         14 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein the housing comprises 6-32 leather pieces. 
     
     
         15 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein the tube body is a double layer tube body comprising an internal layer body and an external layer body tightly attached to the internal layer body. 
     
     
         16 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein the rubber layer is an ordinary rubber layer or a foamed rubber layer; after vulcanization, an external surface of the rubber layer forms a layer of dense rubber membrane. 
     
     
         17 . The manufacturing method of the sewn ball, as recited in  claim 9 , wherein the rubber layer comprises an internal layer rubber, a yarn reinforcement layer and an external layer rubber, wherein the internal layer rubber is attached to an interior of the yarn layer, the yarn reinforcement layer is attached to an external surface of the internal layer rubber, the external layer rubber is attached to an external surface of the yarn reinforcement layer.