(a) TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to an environmental-protection shoe tree, which is made of a material that comprises plant grain husks, such as rice husks and wheat husks, as the primary raw material, which is subjected to pulverization to form tiny particles for being further mixed with a rubber material of a proper ratio to form a rice-husk-contained environmental-protection material blocks, which is then deposited into a rolling machine and added with a crosslinking agent for uniform mixture to make an environmental-protection material plate, which is then cut into a desired size and put in a mold to be heated and pressurized for performing molding to eventually form a shoe tree that features recyclability, light weight, and environmental protection. 
       (b) DESCRIPTION OF THE PRIOR ART 
       [0002]    Due to the great consumption of environment resources caused by the development of industry, excessive waste and damage of the entire environment and the very limited Earth resources frequently happen. To cope with such problems, development of various environmental protection products and materials have been put in significant progress for the purposes to make the materials repeatedly usable, and to reduce the consumption of natural resources through recycle and reuse in order to realize protection of the environment. In respect of the manufacture and use of footwear, the material used is often rubber. However, in respect of comfortable use in practical applications, due to the increased emphasis of environmental protection, various shoe soles that show characteristics of environmental protection have been developed and available in the market. For example, the present inventor has been previously issued Taiwan Invention Patent No. 228397 and a corresponding U.S. Pat. No. 6,916,437, which disclose a manufacturing method for an environmental-protection shoe sole, wherein natural fibrous materials, such as rice husks, are used to make a material for manufacturing a shoe sole. Such a manufacturing method gets very popular in the industry and features reduction of rubber consumption and environmental protection; the method is considered a pioneering process for the manufacturing of environmental-protection shoe soles and meets the needs of practical applications. Footwear requires higher property of material and uses more accessories. All the materials that are used in footwear are considered recyclable and reusable. Taking a shoe tree, which is an accessory to footwear, as an example, it is often used inside a shoe ( 30 ) to expand and support the shoe and most of the known shoe trees currently used are made of a mass of crumpled paper ( 31 ) to assist expand and support shoe vamp, as shown in  FIG. 5 . Although, in respect of material, the known shoe tree is made recycled and reprocessed paper sheets and is thus of the characteristics of environmental protection, yet the known crumpled paper based shoe tree provides only very limited help in practically supporting shoe vamp, for they are crumpled in irregular form, which makes them offering only limited assistance in supporting the shoe vamp. Recently, some manufacturers use polyvinylchloride (PVC) material to make blow-molded shoe trees that are in the form of a shell having a shape resembling a front portion of a shoe. In the manufacturing of shoe tree, such a shoe tree can be made in a configuration that provide uniform support in the use thereof, but the plastic material used to make the shoe tree is based on refinement of fossil material, which requires before-manufacture processing for making shoe tree that requires consumption of energy and uses a complicated process. Thus, this does not really comply with environmental protection. In particular, a lot of advanced countries in the world prohibit the importation of PVC products for it does not comply with environmental protection. Thus, in the manufacture of shoe tree, no product that better comply with environmental protection is available. It is therefore desired to provide development and use of a novel environmental-protection product of shoe accessories by expanding and improving the technology that is used to make environmental-protection shoe sole for the idea of environmental protection and recycle and reuse of natural resources. 
       SUMMARY OF THE INVENTION 
       [0003]    In view of the drawbacks of not complying practical needs of environmental protection in the conventional manufacture and use of shoe trees, the present invention aims to provide an environmental-protection shoe tree that is made of waste material of rice husks and/or wheat husks, which are subjected to sieving and pulverization to form uniform particle sizes, mixed with pre-compounded rubber material to be deposited, in proper ratios, into a mixing machine for sufficient mixture, followed by rolling to form an environmental-protection material plates in which husk particles are visible and being further subjected to hydraulic pressurization and heating for molding and shaping to thereby form a shoe tree that is made of an environmental-protection material and is recyclable and reusable to make the shoe accessory, shoe tree, in compliance with the requirement of environmental protection. 
         [0004]    The objective of the present invention is to provide a shoe tree, which is made of a primary material of rice husks, together mixed with pre-compounded rubber material, which materials are deposited, in proper ratios, into a mixing machine to be mixed to form a rice-husk-contained environmental-protection material block, which is then added with a crosslinking agent and subjected to rolling to form a raw material plate for molding a shoe tree, the material plate being put in a mold to carry out the molding operation for forming the shoe tree, whereby the shoe tree so made provides the practical efficacies of completely complying with the requirement of environmental protection and being recyclable and reusable and completely meets the needs of economics of production and environmental protection. 
         [0005]    The foregoing objectives 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. 
         [0006]    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 
         [0007]      FIG. 1  is a simplified flow chart for manufacturing an environmental-protection shoe tree in accordance with the present invention. 
           [0008]      FIG. 2  is a perspective view showing a shoe tree in accordance with the present invention. 
           [0009]      FIG. 3  is also a perspective view of the shoe tree of the present invention taken from the bottom side thereof. 
           [0010]      FIG. 4  is a perspective view showing an application of the shoe tree of the present invention in a shoe. 
           [0011]      FIG. 5  is a schematic view showing a conventional way of using known shoe tree. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0012]    The following descriptions are 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. 
         [0013]    The present invention provides a novel environmental-protection shoe tree, by which a conventional shoe tree is re-designed to provide an environmental-protection shoe tree that features easy installation and repeated use and helps realizing both convenient recycling and reduction of waste materials, such as waste husks of agricultural products, through an improved design of material used in the production thereof. The whole production process of the shoe tree will be described with reference to  FIG. 1 , which illustrates a simplified flow chart of the production process, and  FIGS. 2-4 , which show and demonstrate use of a shoe tree in accordance with the present invention. Agricultural wastes, such as rice husks or wheat husks obtained after harvest, provide a fibrous material to serve as a primary raw material ( 10 ) for making the shoe tree and the primary raw material ( 10 ) takes 30-80% of the total material weight of the shoe tree. After collected, the primary raw material ( 10 ) is subjected to sieving and pulverization operation ( 11 ) to make proper tiny particles, preferably having a size less than 3 mmφ. A rubber material ( 12 ) is rolled and compounded in advance to make it a rubber raw material that is properly softened and effectively enhanced in respect of tackiness. The rubber material ( 12 ) may take a percentage of 12-60% of the total material weight of the shoe tree produced and may comprise natural rubber, synthetic rubber, and other processed rubbers. Additives ( 13 ) added to the raw materials mentioned above may include powder of zinc oxide, stearic acids, activators, and prompters, which in total take a percentage of 8-10% of the total material weight of the shoe tree produced. The rubber material ( 12 ), after having been properly compounded, and the chemical additives ( 13 ) are deposited, in proper ratios, in a mixing machine and a husk raw material ( 10 ) of an amount providing a proper ratio is added to the mixing machine to carry out sufficient mixing operation ( 14 ). After the mixing operation, rubber material blocks are provided. The blocks are then fed into a rolling machine to perform cyclic rolling operation, in which the material of the blocks is subjected to rolling with a crosslinking agent having a percentage of 1-2%, whereby the material blocks formed by the mixing operation ( 14 ) is rolled by rolls of the rolling machine to form a uniform material plate ( 15 ) preferably having a plate thickness of 1-50 mm. The material plate ( 15 ) is then subjected to slitting to form elongate straps of which the size is dependent upon the size of the shoe tree to be made and the molding thickness thereof. The straps are deposited in a shaping mold of a hydraulic machine to be heated and pressurized for carrying out a molding operation ( 16 ), by which a shoe tree having an outer configuration resembling a front or tip portion of a shoe is made. The outer configuration of the shoe tree ( 20 ) so made is preferably provided with a flange ( 21 ) for easy gripping by a hand, which allows for hand gripping in the use thereof. In this way, a final product ( 17 ) of the husk-contained environmental-protection shoe tree is completed. 
         [0014]    In the production of shoe tree for footwear as discussed above, waste husks of for example rice and wheat is used as the primary raw material ( 10 ), and is added with the rubber raw material ( 12 ) of natural and/or synthetic rubbers, with proper amounts of additives ( 13 ), is subjected to mixing to make the shoe tree. In respect of the chemical additives ( 13 ), natural active bamboo charcoal particles, bamboo vinegar solution, specific essences for bacteriostasis and deodorization, and/or tiny particles that irradiate far infrared radiations, can selectively added to meet the needs of practical applications and the amount added is dependent upon the needs of the practical applications, preferably between 2-15%. These additional additives provide the shoe tree so produced with the hygienic functions of bacteriostasis and deodorization for a shoe when the shoe tree is inserted into the shoe. This makes the practical effectiveness of the shoe tree versatile. 
         [0015]    The shoe tree made in accordance with the present invention, after been used, can be naturally decomposed and/or recycled and reused due to the fact that all the materials used to make the shoe tree are recyclable substances that are environment conservative materials. This is considered a completely environment conservative structure and material, which is formed by uniformly mixing primarily rice husks with natural rubber, together with a proper amount of chemical additive ( 13 ). Thus, the primary constituent component of the shoe tree structure is rice husk, and rubber material ( 12 ) plays only a role of adhesive for bonding the rice husks. All the materials of the constituent components are easily recyclable and particularly, the finished product so produced can be torn or broken into small pieces that allow for easy decomposition in a natural way through exposure to sun light and rain waters to become organic fertilizers for soils. Or alternatively, they can be collected and pulverized again to serve as raw material for reuse in the manufacture with proper adjustment of the amount thereof mixed in the material used in the manufacturing process. In this way, the materials can be reused for the production. Thus, the production process provided for the making shoe tree in accordance with the present invention provides a perfect mode for processing waste materials that complies with environmental conservation and also greatly alleviates the problems of handling agricultural wastes that might cause undesired contamination or pollution to the surroundings, so that the production of shoe accessory may become a novel development of environmental-protection product of which the process is simple and allows for arrangement and control of production in an automatic and continuous manufacturing line. In this respect, the present invention can be considered a novel and practical design for production of environmental-protection shoe tree. The practicability of the product and the whole manufacturing of the product offer significant benefit in respect of environmental protection. The whole process of production is mostly carried out with mixing operation that is carried out with automatic machines so that human labor and skill needed in the production process are very little and the material costs can be minimized, thereby providing practical efficacies of environmental protection and economics and also offering other practical effect of hygiene of footwear. 
         [0016]    To summarize, the present invention provides a novel environmental-protection shoe tree, wherein rice husk is used as the primary raw material for making the shoe tree by being mixed with rubber materials to make a material plate for molding a product of shoe tree. The use of a large amount of rice husk to mix with rubber material makes the process environmentally protective and economic, practical, and safe. 
         [0017]    Several examples of the shoe trees made with the materials discussed above with different component ratio are given in the following table for comparison purposes. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 primary 
                   
                   
                   
               
               
                 material 
                 rubber 
               
               
                 (rice husk) 
                 material 
                 additives 
                 difference in effectiveness of use 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 80% 
                 12% 
                 8% 
                 The amount of rice husk is great and the 
               
               
                   
                   
                   
                 rice husk must be ground to minute 
               
               
                   
                   
                   
                 powders of 300 mesh in order to be 
               
               
                   
                   
                   
                 effectively bonded with rubber and a 
               
               
                   
                   
                   
                 shoe tree made with this material is 
               
               
                   
                   
                   
                 brittle and is susceptible to cracking due 
               
               
                   
                   
                   
                 to excessive ratio of rice husk contained 
               
               
                   
                   
                   
                 therein. The product is of poor quality 
               
               
                   
                   
                   
                 and is not a practical one. 
               
               
                 56% 
                 35% 
                 9% 
                 This material is easy to mold, shows 
               
               
                   
                   
                   
                 certain toughness, provides proper 
               
               
                   
                   
                   
                 resistance against compression, is not 
               
               
                   
                   
                   
                 easy to break or crack, and is thus a 
               
               
                   
                   
                   
                 proper composition for practical shoe 
               
               
                   
                   
                   
                 tree. 
               
               
                 30% 
                 60% 
                 10% 
                 Due to less contents of rice husk, this 
               
               
                   
                   
                   
                 composition requires a large amount of 
               
               
                   
                   
                   
                 rubber and thus provides enhanced 
               
               
                   
                   
                   
                 resistance against compression, but the 
               
               
                   
                   
                   
                 whole manufacturing cost is increased 
               
               
                   
                   
                   
                 and is thus not suitable for 
               
               
                   
                   
                   
                 manufacturing shoe tree and having 
               
               
                   
                   
                   
                 poor market competition. 
               
               
                   
               
             
          
         
       
     
         [0018]    The above table provides several examples of different composition or formula of the material used to make the shoe trees in accordance with the present invention and it is known from the table that in the production process of manufacturing shoe tree in accordance with the present invention, when the percentage of the primary raw material of rice husk exceeds 80%, the manufacturing costs will be raised and the material characteristics become easily cracking and brittle, which does not meet practical needs. Thus, the amount of rice husk is preferably controlled not exceeding 80%. 
         [0019]    When the percentage of the primary raw material of rice husk mixed in the formula is less than 30%, a large amount of rubber is needed. This increases the overall manufacturing costs. Due to the fact that a shoe tree is practically considered a cheap stuff, such increased manufacturing costs make it adverse in respect of sale competition and thus completely unsuitable for practical applications. 
         [0020]    A preferred formula for making the shoe tree in accordance with the present invention includes the primary raw material of rice husk between 55-62%, rubber material between 30-35%, and additives between 8-10%. A formula containing constituent components in these ranges meet the need of practical manufacturing and provide sufficient support to shoe and allows for convenient recycling for reuse and is thus considered the preferred composition of the material used in the present invention. 
         [0021]    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.
The present invention relates to the manufacture of a novel environmental-protection shoe tree, and particularly to the manufacture of an environmental-protection shoe tree made by molding a primary material of rice husk, in which fibrous plant materials, such as rice husks and wheat husks are sieved and pulverized and are mixed with natural rubber and additives, followed by mechanical mixing to carry out a uniform mixing operation for forming an environmental-protection material block, which is then processed by a rolling machine to uniformly mix with a crosslinking agent and form an environmental-protection material plate, which is then cut into a desired size and put in a mold to be heated and pressurized by a hydraulic machine for performing molding to eventually form a final product of a shoe tree showing characteristics of environmental protection.