Leak-free american football

Abstract

Provided is a leak-free American football, which has a polyurethane foam having a shape of an American football; a covering formed on an exterior surface of the polyurethane foam and having a seam; multiple pairs of lacing holes formed in the covering along two opposite sides of the seam, and a lace passing through the multiple pairs of the lacing holes to close the seam, such that the polyurethane foam is covered by the covering and the lace. Since the polyurethane foam is solid and elastic, the leak-free American football can maintain a desired size, shape and bounce without the need for inflation, thereby improving the stability and durability.

What is claimed is: 
     
         1 . A leak-free American football, having:
 a polyurethane foam having a shape of an American football;   a covering formed on an exterior surface of the polyurethane foam and having a seam;   multiple pairs of lacing holes, each pair of the lacing holes formed in the covering respectively along two opposite sides of the seam, and   a lace passing through the multiple pairs of the lacing holes to close the seam, such that the polyurethane foam is covered by the covering and the lace.   
     
     
         2 . The leak-free American football as claimed in  claim 1 , wherein the polyurethane foam has a density ranging from 85 kg/m 3  to 200 kg/m 3 . 
     
     
         3 . The leak-free American football as claimed in  claim 2 , wherein the polyurethane foam has a density ranging from 85 kg/m 3  to 105 kg/m 3 . 
     
     
         4 . The leak-free American football as claimed in  claim 1 , wherein the polyurethane foam has a hardness ranging from 40 Shore A to 70 Shore A. 
     
     
         5 . The leak-free American football as claimed in  claim 2 , wherein the polyurethane foam has a hardness ranging from 40 Shore A to 70 Shore A. 
     
     
         6 . The leak-free American football as claimed in  claim 3 , wherein the polyurethane foam has a hardness ranging from 40 Shore A to 70 Shore A. 
     
     
         7 . The leak-free American football as claimed in  claim 1 , wherein the covering has a thickness ranging from 0.6 to 3.0 millimeters. 
     
     
         8 . The leak-free American football as claimed in  claim 3 , wherein the covering has a thickness ranging from 0.6 to 3.0 millimeters. 
     
     
         9 . The leak-free American football as claimed in  claim 4 , wherein the covering has a thickness ranging from 0.6 to 3.0 millimeters. 
     
     
         10 . The leak-free American football as claimed in  claim 1 , wherein the shape of the American football is substantially prolate spheroidal. 
     
     
         11 . The leak-free American football as claimed in  claim 1 , wherein the covering is made of polyvinyl chloride leather, polyurethane leather, microfiber leather or cow leather. 
     
     
         12 . The leak-free American football as claimed in  claim 1 , wherein an adhesion layer is formed between the covering and the polyurethane foam for adhering the covering onto the exterior surface of the polyurethane foam. 
     
     
         13 . The leak-free American football as claimed in  claim 1 , wherein the covering includes a first section formed on the exterior surface and a second section formed on the exterior surface and adjacent to the first section, the seam is formed between the first section and the second section, a part of the lacing holes are formed in the first section along one of the two opposite sides of the seam, and the other lacing holes paired with said part of the lacing holes are formed in the second section along the other side of the seam, and positions of the lacing holes formed in the first section correspond to positions of the lacing holes formed in the second section. 
     
     
         14 . The leak-free American football as claimed in  claim 13 , wherein the lace has two ends opposite to each other and a lacing body formed between the ends, the lacing body of the lace passes through the multiple pairs of the lacing holes, and the ends of the lace are inserted into the seam and between the lacing body of the lace and the polyurethane foam. 
     
     
         15 . The leak-free American football as claimed in  claim 1 , wherein the leak-free American football has a pattern on the covering. 
     
     
         16 . The leak-free American football as claimed in  claim 6 , wherein the shape of the American football is substantially prolate spheroidal. 
     
     
         17 . The leak-free American football as claimed in  claim 15 , wherein the covering is made of polyvinyl chloride leather, polyurethane leather, microfiber leather or cow leather. 
     
     
         18 . The leak-free American football as claimed in  claim 16 , wherein the covering includes a first section formed on the exterior surface and a second section formed on the exterior surface and adjacent to the first section, the seam is formed between the first section and the second section, a part of the lacing holes are formed in the first section along one of the two opposite sides of the seam, and the other lacing holes paired with said part of the lacing holes are formed in the second section along the other side of the seam, and positions of the lacing holes formed in the first section correspond to positions of the lacing holes formed in the second section. 
     
     
         19 . The leak-free American football as claimed in  claim 18 , wherein the lace has two ends opposite to each other and a lacing body formed between the ends, the lacing body of the lace passes through the multiple pairs of the lacing holes, and the ends of the lace are inserted into the seam and between the lacing body of the lace and the polyurethane foam. 
     
     
         20 . The leak-free American football as claimed in  claim 19 , wherein an adhesion layer is formed between the covering and the polyurethane foam for adhering the covering onto the exterior surface of the polyurethane foam.