Patent Publication Number: US-5155913-A

Title: Method for making a knife and a product corresponding to the method

Description:
The object of this invention is a method for making a knife and a knife made using this method. 
     Knives are generally made by inserting the root end of the knife blade into a bore in the handle piece. The root end of the knife blade is then riveted, or screwed from one end to keep it in place. In addition, a ferrule is placed at the blade-end of the handle to prevent the handle material from cracking easily and to keep the handle immobile. The handle may be of wood, rubber, etc. 
     The above mentioned method is extremely difficult to automate. The riveting stage requires the use of human labour and consequently the manufacturing costs can become high. 
     The method in accordance with the invention results in decisive improvements with regard to the above mentioned disadvantages. For the realization of these improvements, the method of making a knife in accordance with the invention is mainly characterized by what is presented in the characterization part of the patent claim 1 and the product is characterized by what is presented in the characterization part of the claim 5. 
     The invention&#39;s foremost advantage may be seen to be the automation of the making of the knife from start to finish. As a result of this automation, the costs of making the knife are reduced, thus making the knife competitive. The riveting stage can be omitted altogether and the insertion of the ferrule is not necessary because the advantages of the ferrule (e.g. support given to the handle) are achieved by gluing. 
    
    
     In the following, the invention is described by referring to the figures of which 
     FIG. 1 is a schematic presentation of parts connected to the knife in accordance with the invention; 
     FIG. 2 depicts a sectional view on the line A--A in FIG. 1; 
     FIG. 3 depicts a sectional view on the line B--B in FIG. 1; 
     FIG. 4 depicts a split view of another kind of intermediate and/or ferrule piece connected to the knife in accordance with the invention; 
     FIG. 5 depicts an assembled knife such as that depicted in FIG. 1; 
    
    
     In FIG. 1, the blade is designated by reference number 1, the integral intermediate and ferrule piece by 2, the blade&#39;s root end by 3. In the method according to the invention, the blade 1 and the intermediate and ferrule part 2 are joined to one another by gluing by inserting the blade into the gap or groove 4 in piece 2. Thereafter, or concurrently with the gluing operation, the blade 1 and the intermediate and ferrule piece 2 are inserted into the longitudinal bore 6 in the middle of the handle 5. The diameter of bore 6 is close to or essentially the same as the external diameter of the elongated part 7 of the intermediate part 2. On the other hand, the cross-sections of the bore 6 and of the elongated part 7 of the intermediate piece need not be circular. The joints between the various parts are thus in this case formed by gluing. The method can be used for several kinds of blades having the root end of the shape so as to fit into the gap or groove 4. 
     FIG. 4 depicts an elongated intermediate piece of another shape. Such a piece can be used if the intention is to place a separate ferrule over the intermediate piece. Although the use of a separate ferrule is avoided by the use of the preferred method. 
     The gap or groove 4 in the intermediate piece 2 is of such shape as will permit the blade&#39;s root end to be inserted into it and its shape is advantageously close to the cross section of the root end of the blade. 
     The intermediate piece 2 can be made to be of any form at the point of the hand protectors 8. The hand protectors 8 located between the handle 5 and the blade 1 can be made to be of various forms. The handle end of the intermediate piece can be provided with a circumferential recess into which that end of the handle which is close to blade can be inserted to provide support for the handle. 
     The intermediate piece 2 may be made of plastic, bronze, aluminum or corresponding materials. If the handle is made of rubber or some other corresponding material, then it is best to make the root end of the blade to extend almost the entire length of the handle in order to make the handle sufficiently stiff. 
     The order in which gluing is carried out may also vary; that is, first the intermediate piece is glued onto the handle and then the blade is glued onto the former. In actual fact, the most advantageous way is to first glue the intermediate piece onto the root end of the blade and then or simultaneously into the handle. 
     The hand protector may be given a surface treatment by nickel-plating in the case of aluminum or some other type of surface treatment depending on the properties of the material used in constructing the intermediate piece. 
     The root end of the blade can be perforated or have slits or other irregularities, allowing the adhesive to pass through the root end of the blade ensuring firmer adhesion. The root end of the blade can also be made to have an uneven surface as a means of improving the adhesive strength of the glue. 
     We have described the invention by referring to only one advantageous example of its implementation. The solutions presented in the above and in the accompanying figures are examples which are in no way intended to limit the invention. 
     Instead, all modifications within the framework of the inventive idea defined in the patent claim are, naturally, possible.