BACKGROUND OF THE INVENTION Field of the Invention This invention relates to tires and, more specifically to high-elasticity tires and a method of preparing same.

Background Information Airless tires have been developed in response to the many shortcomings, such as vulnerability to punctures, tendency to leak, and bursting, that pneumatic tires suffer. The airless tires that are currently on the market are solid-core tires, i.e. the entire tire, both tire surface and tire core, are manufactured as a single component from the same materials. Although this type of airless tire has overcome some of the defects of pneumatic tires, these tires, on account of having a solid core, suffer from nettlesome problems such as heaviness, poor elasticity, and high kinetic energy- depletion. Furthermore, these solid-core tires are made primarily from recycled rubber. Thus, their performance in the areas of abrasion-resistance, impact- cushioning, and aging-resistance is not sufficient to meet the needs of the marketplace, particularly the tire needs of tool carts or other vehicles (bicycles, tricycles, hand trucks, and utility carts).

SUMMARY OF THE INVENTION The object of the present invention is to overcome the deficiencies of the current art and to provide a lightweight, highly elastic, abrasion-resistant, airless high- elasticity tire and a method of preparing same. This high-elasticity tire consists of a tire surface and a tire core thermally bonded by means of a vulcanizing mold. The composition and weight percentages of the tire core are: Natural rubber 31.0-33.0 Natural latex 9.4-9.8 Light calcium 37.8-39.0 Carbon black 4.7-4.9 Zinc oxide 1.7-1.9 Sulfur 0.7-0.8 Antiaging A 0.5-0.7 Stearic acid 0.9-1.1 Accelerator 0.09-0.11 Foaming agent 3.1-3.3 Urea 1.5-1.7 Vaseline 4.5-4.9 The composition and weight percentages of the tire surface are: Natural rubber 45.8-49.2 Butadiene styrene rubber 6.0-6.5 High styrene 3.0-3.3 Polyvinyl chloride resin 3.0-3.3 Carbon black 18.4-18.9 Zinc oxide 3.0-3.3 Sulfur 1.2-1.6 Stearic acid 0.6-0.8 Antiaging agent #4010 0.4-0.6 Antiaging agent D 0.4-0.6 Coumarone 1.8-2.0 Vaseline 12.0-13.1 Accelerator DM 0.4-0.6 Accelerator D 0.3-0.4 In addition to the tire materials identified above, another material may be added, namely, white factice. The white factice has a weight percent of 1.4-1.7. In addition to the materials identified above, the tire surface may have other materials added. These, and their weight percentages, being: Zinc stearic acid 0.5-0.6 Barium stearic acid 0.5-0.6 Silica 5.4-5.6 Paraffin wax 0.8-0.9 Rosin 0.4-0.5 Magnesium oxide 1.6-1.7 The tire core foaming agent may be one of the following: a carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, a nitroso-compound, N, N'-dimethyl, N'-dinitroso-terephthalamide, an organic foaming agent: p- toluenesulfonyl hydrazide, disulfohydrazide, p-p-sulfohydrazide diphenyl ether, an azo-compound, azodicarbonamide, improved azodicarbonamide, and barium azodicarboxylate. The process of preparing the high-elasticity tire comprises a tire core preparation process, a tire surface preparation process, and an assembly process for the finished product. The process of preparing said high-elasticity tire comprises a tire core preparation process, a tire surface preparation process, and an assembly process for the finished product. I. Tire Core Preparation Process The tire core preparation process comprises a natural rubber plasticization step, a mixing step, a fine milling and heating step, and a rubber rod extrusion step; the specific preparation method is: 1. Plasticization of Natural Rubber: a. After weighing a proportionate amount of natural rubber (China National Product No. 1 Natural Rubber), cut into pieces and mill in an open rubber mill. The required rolling clearance of the rubber mill is 1-1.5 mm. The rolling temperature of the front roller should be no higher than 50-550C, and the rolling temperature of the rear roller should be no higher than 55-6O0C. With each pass, use the reverse- substitute method to feed rubber into the rubber mill. Complete a total of 11-13 passes. b. Increase the rolling clearance to 7-8 mm. Feed the rubber into the rubber mill. Making four left-to-right cuts, pound and mill 3-5 times. Rubber is formed into a rubber piece 7-8 mm thick. c. Discharge rubber, and cool with cold water in a tub at about 1O0C for 20 minutes. d. Take out rubber. Powder top and bottom with talcum powder. Set aside for 8 hours. e. Repeat steps a-d twice, i.e., plasticize a total of three times, to achieve a rubber plasticity of 0.55-0.60. The rubber pieces now enter the mixing step. 2. Mixing a. Set the roller clearance of the rubber mill to 1-1.5 mm. Set the rolling temperature of the front roller to no higher than 40-450C and the temperature of the rear roller to no higher than 45-500C. Then feed the plasticized rubber pieces into the rubber mill to mill the rubber. Add latex according to proportion. Complete 3 passes. b. Feed rubber into rubber mill. After one pass, add a mixture of zinc oxide, accelerator, stearic acid, antiaging A, and coumarone according to the proper weight proportions to the rubber pieces. Then add a proportionate amount of Vaseline, until the above additives melt into the rubber pieces evenly. c. Add mixture of light calcium and carbon black according to proper proportions until these two additives melt evenly into rubber pieces. d. Add mixture of foaming agent, sulfur, and urea according to proper proportions, and complete 3 passes after these additives have melted evenly into rubber pieces. e. Raise roller clearance of rubber mill to 7-8 mm. Making four left-to-right cuts, pound and mill 3-5 times; rubber is formed into a rubber piece 7-8 mm thick. f. Discharge rubber, and cool with cold water in a tub at about 1O0C for 20 minutes. g. Take out rubber; powder top and bottom with talcum powder; set aside for 8 hours. 3. Fine Milling and Heating a. Set roller clearance to 3-4 mm. Set rolling temperature of front roller to no higher than 40-450C and temperature of rear roller to no higher than 45-5O0C. Then feed the plasticized rubber pieces into the rubber mill to heat and soften, and smooth top and bottom surfaces of rubber. b. Set roller clearance to 1-1.5 mm. Add rubber in form of triangular packets or by reverse-substitution. Complete 4-5 passes. c. Set roller clearance to 4-5 mm. Now discharge 4-5 mm rubber strips 50 mm wide. 4. Rubber Rod Extrusion a. Rubber rods are shaped on the extruder. Heat the chamber, head, and die of the extruder with steam. The chamber needs to reach 35-4O0C, the head 40-500C, and the die 60-700C. b. Feed the rubber strips from the previous step directly and in adequate amounts into the chamber of the extruder. After passing through the chamber, these rubber strips are extruded through the dies, forming rubber rods. c. As necessary, bevel the rubber rods at 45° angles. Paint beveled surfaces with gasoline. Then roughen surfaces with a metal brush, and set aside five minutes, joining to form a closed pole ring, i.e., the tire core, to be used later. II. Tire Surface Preparation Process 1. Plasticizing of Natural Rubber The tire surface is plasticized in the same way as the tire core. The only difference is that during the third stage of plasticization, the front and rear rolling temperatures need to reach 60-700C. Otherwise, it is plasticized in the same way as the tire core. 2. Mixing a. Set the roller clearance of the rubber mill to 1-1.5 mm. Set the rolling temperature of the front roller to no higher than 40-450C and the temperature of the rear roller to no higher than 45-500C. Then feed the plasticized rubber pieces into the rubber mill to mill the rubber. Complete 3 passes. b. Feed rubber into rubber mill. After one pass, add a mixture of zinc oxide, accelerator DM, accelerator D, stearic acid, antiaging agent D, antiaging agent #4010, and coumarone according to the proper weight proportions to rubber. Then add Vaseline according to proportion, until the above additives melt into the rubber pieces evenly. c. Add mixture of proper proportions of butadiene styrene rubber, high styrene, polyvinyl chloride resin, carbon black, and silica to the rubber. Melt these additives into the rubber evenly. Complete 3 passes. d. The remaining steps are the same as the tire core mixing steps e-g. 3. Fine Milling and Heating Same as the fine milling and heating step for the tire core, with the tire surface as end product. III. Assembly Process 1. Roll-press the contact surfaces of the tire surface on the inner circle of the tire core; maintain the smoothness and evenness of the outer surface of the tire surface. 2. Put the tire surface-tire core assembly into a vulcanizing [sic] to form the tire, with a vulcanization index of 3.5 MPa x 20 minutes. 3. Set the vulcanization mold oil pressure at 100 MPa, and press the molds vertically, releasing steam three times to form the finished tire. Furthermore, in part d of the mixing step of the tire core, a proportionate amount of white factice is added to the mixture of foaming agent, sulfur, and urea. In part b of the mixing step of the tire surface, proportionate amounts of paraffin wax, rosin, zinc stearic acid, barium stearic acid, and magnesium oxide can be added together with the mixture of zinc oxide, accelerator DM, accelerator D, stearic acid, antiaging agent D, antiaging agent #4010, and coumarone. The present invention has these advantages and positive effects: 1. The tire core is a polymer sponge foam consisting primarily of foamed natural rubber. Its specific composition is quite simple, and it has quite a reasonable production process. It has outstanding chemical and physical properties. The manufactured tire core is highly elastic, lightweight and largely unaffected by impact, and it has good anti-vibration and load-bearing qualities. 2. The tire surface is mainly composed of natural rubber, polyvinyl chloride resin, high styrene, and other additives. It has good resistance to abrasion, aging, and shock and has good cushioning qualities. It entirely complies with the various physical and chemical technical standards for tires of tool carts and other vehicles. 3. The use of foaming agents of various performance levels in the vulcanizing and heating process can meet the various hole size requirements of the resulting rubber sponge, whether closed or open-pore, and thus produce airless rubber tires of various functions. 4. The tire core and tire surface are hot-pressed together by means of a vulcanizing mold, endowing the tire product formed thereby with outstanding quality and entirely overcoming the defects of current airless tires. It is a substitute product for current airless tires. In addition, a ridge is formed on the inner circumference of the tire surface of this product. This allows the tire to be seated firmly within the wheel rim. Tires having such a structure are especially suited to the tire needs of tool carts and other vehicles (bicycles, tricycles, wheel barrows, and utility carts).

DESCRIPTION OF THE PREFERRED EMBODIMENTS As used herein all percentages are given by weight. All of the materials identified below and used to make the high-elasticity tire 10 are National Standard-compliant products sold on the market, and each embodies its own particular function, without special technical requirements and explanations. The rubber mill and the extruder are currently existing products and will not be discussed further here. The high-elasticity tire 10 for human-powered vehicles of the present invention consists of a tire surface 12 and a tire core 14. The tire core 14 is made from the following materials proportioned according to the subsequently identified weight percentage: Natural rubber 31-33 Natural latex 9.4-9.8 Light calcium 37.8-39.0 Carbon black 4.7-4.9 Zinc oxide 1.7-1.9 Sulfur 0.7-0.8 Antiaging A 0.5-0.7 Stearic acid 0.9-1.1 Accelerator 0.09-0.11 Foaming agent 3.1-3.3 Urea 1.5-1.7 Vaseline 4.5-4.9 White factice 1.4-1.7 The foaming agent may be one of the following: a carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, a nitroso-compound, N, N'-dimethyl, N'-dinitroso-terephthalamide, an organic foaming agent, p- toluenesulfonyl hydrazide, disulfohydrazide, p-p-sulfohydrazide diphenyl ether, an azo-compound, azodicarbonamide, improved azodicarbonamide (AC-K), and barium azodicarboxylate. . The foaming agent can generate a large quantity of gas in the vulcanization heating process and may be described as a specialized compounding ingredient that causes the product to develop a porous structure. The compounding ingredient is necessary for producing rubber foam products (open-pore or closed-pore tire core) and micropore rubber cores. For a tire core 14 that needs to have an open-pore structure, an inorganic foaming agent such as a carbonate—sodium carbonate, ammonium carbonate, or ammonium bicarbonate and an azo-compound—azodicarbonamide, improved azodicarbonamide (AC-K), or barium azodicarboxylate, may be used. For a tire core that needs to have a closed-pore structure, a nitroso-compound~N, N' -dimethyl, N'- dinitroso-terephthalamide and an organic foaming agen~p-toluenesulfonyl hydrazide, disulfohydrazide, or p-p-sulfohydrazide diphenyl ether, may be used. The tire surface 12 is made from the following materials proportioned according to the subsequently identified weight percentage: Natural rubber 45.8-49.2 Butadiene styrene rubber 6.0-6.5 High styrene 3.0-3.3 Polyvinyl chloride resin 3.0-3.3 Carbon black 18.4-18.9 Zinc oxide 3.0-3.3 Sulfur 1.2-1.6 Stearic acid 0.6-0.8 Antiaging agent #4010 0.4-0.6 Antiaging agent D 0.4-0.6 Coumarone 1.8-2.0 Vaseline 12.0-13.1 Accelerator DM 0.4-0.6 Accelerator D 0.3-0.4 Zinc stearic acid 0.5-0.6 Barium stearic acid 0.5-0.6 Silica 5.4-5.6 Paraffin wax 0.8-0.9 Rosin 0.4-0.5 Magnesium oxide 1.6-1.7 The method of preparing the high-elasticity tire 10 comprises a tire core 14 preparation step 20, a tire surface 12 preparation step 140, and an assembly step 210 for the finished product. These steps are described in detail below. The tire core preparation step 20 includes the following steps: a natural rubber plasticization step 22, a mixing step 60, a fine milling and heating step 100, and a rubber rod extrusion step 120. More specifically, the plasticization of natural rubber step 22 is accomplished as follows. First a proportionate amount of natural rubber (China National Product No. 1 Natural Rubber) is weighed 24. The rubber is cut 26 into pieces and milled 28 in an open rubber mill. The rolling clearance of the rubber mill is set 27 at 1-1.5 mm. The rolling temperature of the rollers is set 29 as follows: the front roller should be no higher than 50-550C, and the rolling temperature of the rear roller should be no higher than 55-6O0C. With each pass, the reverse-substitute method is used to feed 30 rubber into the rubber mill. The rubber is passed through the mill for a total of 11-13 passes. The rolling clearance is then increased 31 to 7-8 mm. The rubber is again fed 32 into the rubber mill. The rubber is cut 34 by four left-to-right cuts. The rubber is then pounded 36 and milled 38 3-5 times. This procedure forms a rubber piece 7-8 mm thick. The rubber is then discharged 40, and cooled 42 with cold water in a tub at about 1O0C for 20 minutes. The rubber is removed 44 from the tub and powdered 46 top and bottom with talcum powder. The rubber is then set aside 48 for 8 hours. The steps identified by reference numbers 24-48 are repeated 50 twice, i.e., the rubber is plasticize a total of three times, to achieve a rubber plasticity of 0.55-0.60. The rubber pieces now enter the mixing step 60. The mixing step 60 is accomplished as follows. The rubber mill roller clearance is set 62 to 1-1.5 mm. The rolling temperature of the rollers is set 64 with the front roller to no higher than 40-450C and the temperature of the rear roller to no higher than 45-5O0C. Then plasticized rubber pieces is fed 66 into the rubber mill to mill the rubber. At this time, latex is added 68 to the rubber according to proportion identified above. Three passes of the rubber through the rubber mill are completed and the rubber is removed 69. The rubber is again fed 70 into rubber mill. After one pass, a mixture of zinc oxide, accelerator, stearic acid, antiaging A, and coumarone is added 72 according to the proper weight proportions to the rubber pieces. Then a proportionate amount of Vaseline is added 74. The rubber is milled until the above additives melt into the rubber pieces evenly. A mixture of light calcium and carbon black is then added 76 according to the proportions identified above, until these two additives melt evenly into the rubber pieces. A mixture of a foaming agent, sulfur, and urea are then added 78 according to the proportions identified above. White factice may also be added 79 according to the proportions identified above. The rubber is passed through the mill three times after these additives have melted evenly into the rubber pieces. The roller clearance of rubber mill is then raised 80 to 7-8 mm. The rubber is cut 82 by making four left-to-right cuts, and the rubber is pounded 84 and milled 86 3-5 times. This creates a rubber piece 7-8 mm thick. The rubber is discharged 88, and cooled 90 with cold water in a tub at about 1O0C for 20 minutes. The rubber is then removed 92 from the water, powdered 94 top and bottom with talcum powder, and set aside 96 for 8 hours. The fine milling and heating step 100 includes the following steps. The rubber mill roller clearance is set 102 to 3-4 mm. The rolling temperature of the mill is then set 104 with the front roller no higher than 40-450C and temperature of rear roller no higher than 45-5O0C. The plasticized rubber pieces are then fed 106 into the rubber mill to heat, soften, and smooth the top and bottom surfaces of the rubber pieces. The roller clearance is set 108 to 1-1.5 mm and rubber in the form of triangular packets is added 110. This step may also be accomplished by reverse- substitution. The rubber is passed through the mill for 4-5 passes. The roller clearance is then set 112 to 4-5 mm and rubber strips 4-5 mm by 50 mm wide are discharged 114. The rubber rod extrusion step 120 includes the following steps. The extruder chamber, head, and die are heated 122, with steam. The chamber is heated to 35-4O0C, the head to 40-500C, and the die to 60-700C. The rubber strips from the milling and heating step 100 are fed 124 directly and in adequate amounts into the chamber of the extruder. After passing through the chamber, these rubber strips are extruded 126 through the dies, forming rubber rods. The rubber rods are beveled 128 at 45° angles as required. The beveled surfaces are then painted 130 with gasoline. The surface of the rod is abraded 132 with a metal brush, and the rods are set aside 134 for five minutes. Finally, the rods are joined 136 to form a closed pole ring, i.e., the tire core, to be used later. The tire surface preparation step 140 includes a natural rubber plasticization step 142, a mixing step 150, a fine milling and heating step 190 The plasticizing of natural rubber step 142 includes the following steps. The tire surface is plasticized generally in the same way as the tire core. That is, first a proportionate amount of natural rubber (China National Product No. 1 Natural Rubber) is weighed 143. The rubber is cut 144 into pieces and milled 145 in an open rubber mill. The rolling clearance of the rubber mill is set 146 at 1-1.5 mm. The rolling temperature of the rollers is set 147 as follows: the front roller should be no higher than 50-550C, and the rolling temperature of the rear roller should be no higher than 55-6O0C. With each pass, the reverse-substitute method is used to feed 148 rubber into the rubber mill. The rubber is passed through the mill for a total of 11-13 passes. The one difference is that during the third stage of plasticization, the front and rear rolling temperatures are set 149 to reach 60-700C. The mixing step 150 includes the following steps. The roller clearance of the rubber mill is set 152 to 1-1.5 mm and the rolling temperature is set 154 with the front roller no higher than 40-450C and the temperature of the rear roller no higher than 45- 5O0C. The plasticized rubber pieces are fed 156 into the rubber mill to mill the rubber until 3 passes are completed. The rubber may be removed 158 from the mill. Additional materials are then added by feeding 160 the rubber into rubber mill. After one pass, a mixture of zinc oxide, accelerator DM, accelerator D, stearic acid, antiaging agent D, antiaging agent #4010, and coumarone are added 162 to the rubber according to the proper weight proportions identified above. Proportionate amounts of paraffin wax, rosin, zinc stearic acid, barium stearic acid, and magnesium oxide may be added 163 to the rubber. Vaseline is then added 164 according to the proportion identified above, until the above additives melt into the rubber pieces evenly. A mixture of butadiene styrene rubber, high styrene, polyvinyl chloride resin, carbon black, and silica are then added 166 to the rubber. These additives are melted into the rubber evenly and three passes are completed. A mixture of a foaming agent, sulfur, and urea are then added 168 according to the proportions identified above. White factice may also be added 170 according to the proportions identified above. The rubber is passed through the mill three times after these additives have melted evenly into the rubber pieces. The roller clearance of rubber mill is then raised 172 to 7-8 mm. The rubber is cut 174 by making four left-to-right cuts, and the rubber is pounded 176 and milled 178 3-5 times. This creates a rubber piece 7-8 mm thick. The rubber is discharged 180, and cooled 182 with cold water in a tub at about 1O0C for 20 minutes. The rubber is then removed 184 from the water, powdered 186, top and bottom, with talcum powder, and set aside 188 for 8 hours. The fine milling and heating step 190 is substantially similar to the fine milling and heating step 100 for the tire core, with the tire surface as end product. That is, the fine milling and heating step 190 for the tire surface includes the following steps. The rubber mill roller clearance is set 192 to 3-4 mm. The rolling temperature of the rubber mill is then set 194 with the front roller no higher than 40- 450C and temperature of rear roller no higher than 45-500C. The plasticized rubber pieces are then fed 196 into the rubber mill to heat, soften, and smooth the top and bottom surfaces of the rubber pieces. The roller clearance is set 198 to 1-1.5 mm and rubber in the form of triangular packets is added 200. This step may also be accomplished by reverse-substitution. The rubber is passed through the mill for 4-5 passes. The roller clearance is then set 202 to 4-5 mm and rubber strips 4-5 mm by 50 mm wide are discharged 204. The assembly step 210 includes the following steps. The contact surfaces of the tire surface are roll-pressed 212 on the inner circle of the tire core while maintaining the smoothness and evenness of the outer surface of the tire surface. The tire surface-tire core assembly are placed 214 into a vulcanizing device for about 20 minutes to form the tire 10, with a vulcanization index of 3.5 MPa. The vulcanization mold oil pressure is set 216 at 100 MPa, and the molds are pressed 218 vertically, releasing steam three times to form the finished tire. When tested, the tire core of an airless rubber tire prepared according to the above method of preparation was found to have the following physical performance levels: Density (g/cm2) 0.345 Tensile strength (MPa) 5.8 Elongation at break (%) 580 Resilience 45 Compression set (85 °C*25%*22h) 57.2 Adhesion strength (KN/M) 1.9 Low-temperature brittleness No break at -450C When tested, the tire surface (including tire walls) was found to have the following physical and mechanical performance levels: Tensile strength (MPa) 18.5 Elongation at break (%) 530 Hardness (Shore A) 58 Modulus at 300% (MPa) 4.2 Set after break (%) 20 Specific density (MA/M3) 1.253 While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.