Abstract:
A cutting tool and its method for manufacture involves a blade member having an extension. Together, the blade member and extension are die cut from sheet metal and a cutting edge is then formed adjacent the extension. A metal or plastic handle is formed with a slit, and the blade member is positioned in the slit to leave the cutting edge exposed between the extension and the handle. The blade member is then secured to the handle.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains generally to cutting implements and their method of manufacture. More particularly, the present invention pertains to methods for manufacturing box cutters. The present invention is particularly, but not exclusively useful as a method for manufacturing box cutters having high strength blades that are effectively shielded to prevent an unintentional or an intentional infliction of injury to the user or to another. 
       BACKGROUND OF THE INVENTION 
       [0002]    Many different laminar-shaped materials are used for many different purposes. As an example of a common use for such a material, consider a cardboard box. Cardboard boxes are well known for their use as shipping or storage containers. For this purpose they are typically configured as a unitary enclosure wherein the various panels of the enclosure are folded and sealed together with commercially available tapes. Typically, such boxes are designed for a one-time use, and it is expected the cardboard may eventually be cut to open the box and retrieve articles or items from inside the box. As another example, consider straps or belts that are used to hold or confine something. There are times when they too must be cut, rather than loosened in a more conventional manner. Many other examples can, of course, be given wherein laminar materials are used and may need to be cut. 
         [0003]    Cutting laminar-shaped material can be a difficult task. This is particularly so if no edge to the material is directly and easily accessible (e.g. a box). In such cases, it is normally necessary to somehow first puncture the material in order to establish access for cutting the material. Also, if the material has any appreciable strength or thickness, the use of a common tool, such as a scissors, may be impractical; if not impossible. A consequence of all this is that special tools have been developed for purposes of cutting laminar-shaped materials. 
         [0004]    Heretofore, an undesirable feature of lamina cutters has been the unprotected exposure of their cutting edge. Specifically, box-cutters and knives that will both penetrate the material, and then cut through the material, have been made with the expectation that the cutting edge will remain openly exposed and unprotected. On the other hand, lamina cutters that are specifically designed with protected blades have typically had to rely on some means, other than the tool itself, to provide initial access for the blade&#39;s cutting edge. Such access is needed to position the blade&#39;s cutting edge where it can make contact with the material that is to be cut. 
         [0005]    In light of the above, it is an object of the present invention to provide a dual-function cutting tool that combines a blunt extension for penetrating through a laminar material, with a protected blade that is exposed, for cutting the material. Another object of the present invention is to provide a method for manufacturing a cutting tool having a two-piece construction that includes: 1) a dual-function cutting member having both an extension for penetrating the material to be cut and a cutting edge for actually cutting the material; and 2) a handle for holding the cutting member to position the cutting blade in a protected space between the extension and the handle. Yet another object of the present invention is to provide a cutting tool, and a method for its manufacture, that is simple to implement, is easy to use, and is comparatively cost effective. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with the present invention, a cutting tool and its method for manufacture involve a dual-function blade member that includes both an extension for puncturing a laminar material, and a protected cutting blade for subsequently cutting the laminar material. The cutting tool, itself, is an integrated two-piece device that includes only the blade member and a handle. 
         [0007]    The blade member of the cutting tool is planar, and it has a substantially rectangular shaped body portion. Further, the blade member is flat and has a substantially uniform thickness “t”. The above-mentioned extension projects in alignment with, and along, a first side of the blade member. Additionally, the extension has an inside edge that is substantially parallel to the first side of the blade member. A cutting blade is formed on the blade member. Specifically, it is oriented to extend perpendicularly from the inside edge of the extension to a second side of the blade member. Within this orientation, the cutting blade is substantially perpendicular to both the inside edge of the extension and to the second side of the blade member. 
         [0008]    The handle of the cutting tool for the present invention is formed with first and second flanges that extend parallel to each other. As so extended, the flanges establish a slit between them. There is a distance “d” between the two flanges (i.e. the width of the slit is “d”), and this distance “d” is equal to or slightly greater than the thickness “t” of the blade member. Each flange has a guiding edge that is located across the slit from the other flange, opposite each other. 
         [0009]    For the manufacture of the cutting tool of the present invention, the second side of the blade member is positioned in the slit of the handle, between the first and second flanges (recall d≧t). This placement orients the cutting blade substantially perpendicular to the guiding edges on the handle. It also positions the inside edge on the extension of the blade member parallel to the guiding edges on the handle. This establishes a slot between them having a width “w”. Importantly, the width “w” is sufficiently small, and the cutting blade is sufficiently deep in the slot, so a person using the tool can not be cut by the cutting blade. The blade member is then secured between the flanges of the handle. 
         [0010]    Preferably, the blade member with its extension is made of a sheet metal, and the blade member is created by die cutting the sheet metal. The cutting blade can then be formed on the blade member. Alternatively, the blade member can be made of a plastic material. If so, it can be formed by injection molding. In either case, the handle is preferably made of a plastic material, and is formed by injection molding. As envisioned for the present invention, the blade member can be secured to the handle by either glue or bolts. When both the blade member and the handle are made of plastic, the blade member can be secured to the handle by thermo-bonding. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
           [0012]      FIG. 1  is a side elevation view of a cutting tool in accordance with the present invention; 
           [0013]      FIG. 2A  is a view of the blade member of the cutting tool as seen in  FIG. 1  with the handle of the cutting tool removed; 
           [0014]      FIG. 2B  is an alternate embodiment of the blade member; 
           [0015]      FIG. 3  is an edgewise view of the blade member shown in  FIG. 2A  or  2 B; and 
           [0016]      FIG. 4  is an edgewise view of the cutting tool shown in  FIG. 1 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Referring initially to  FIG. 1 , a cutting tool in accordance with the present invention is shown and is generally designated  10 . As shown, the tool  10  includes a handle  12  and a blade member  14 . Essentially, the tool  10  is only a two-part device (i.e. handle  12  and blade member  14 ). 
         [0018]    Referring now to  FIG. 2A , the blade member  14  is shown in complete detail. Specifically, with cross-reference to  FIG. 3 , it will be appreciated the blade member  14  is substantially flat, and has a thickness “t” that will typically be within a range of 0.05-0.15 inches. Preferably, the blade member  14  is made of a metal (e.g. stainless steel) and is die cut from a sheet of the material. It is possible, however, that the blade member  14  can be made of a strong, durable plastic material. 
         [0019]    As shown in  FIG. 2A , the blade member  14  has a body portion  16  that is substantially rectangular shaped. It has a side  18  that is opposite, and substantially parallel, to a side  20 . Further, the blade member  14  is formed with an extension  22  that extends along the side  18 . More particularly, the extension  22  is defined by the side  18  and an inside edge  24  that is parallel to the side  18 . As shown in  FIG. 2A , the blade member  14  is also formed with a cutting blade  26  that extends between the inside edge  24  and the side  20  of the body portion  16 . In a preferred embodiment of the cutting tool  10 , the cutting blade  26  will be generally perpendicular to the inside edge  24 , and will define a blade axis  28  that is parallel to the inside edge  24  (i.e. perpendicular to the cutting blade  26 ). 
         [0020]      FIG. 4  shows that the handle  12  is formed with flanges  30   a  and  30   b  that extend on the handle  12  to establish a slit  32  between them. As indicated, the slit  32  will have a width “d” through most (perhaps, all) of the slit  32 . Further, by cross-reference between  FIG. 4  and  FIG. 1 , it will be appreciated that each flange  30   a  and  30   b  has a respective guiding edge  34   a  and  34   b . For the present invention, these guiding edges  34   a,b  are preferably straight. Further, they are mutually parallel, and they are located directly across the slit  32  from each other. 
         [0021]    As most clearly shown in  FIG. 1 , after the blade member  14  has been joined with the handle  12 , the guiding edges  34   a,b  are positioned substantially parallel to the inside edge  24 . This positioning establishes a slot  36  between the extension  22  and the handle  12 . The slot  36  has a width “w” and, importantly, the width “w” is selected to prevent contact between the cutting blade  26  and a digit of the user (not shown). 
         [0022]    For an alternate embodiment of the present invention, a blade member  14 ′ can be shaped substantially as shown in  FIG. 2B . In all important respects, the blade member  14 ′ is substantially similar to the blade member  14  disclosed above. The blade member  14 ′, however, includes a slant edge  38  that gives the blade member  14 ′ a narrower extension  22 ′ than is provided for the blade member  14 . 
         [0023]    In the manufacture of the cutting tool  10  of the present invention, a blade member  14  is created. As indicated above, the blade member  14  is preferably made of a metal material that lends itself to a stamping or die cutting operation. Once a blank blade member  14  has been formed, the cutting blade  26  can be sharpened in a manner well known in the pertinent art. Also, as indicated above, the blade member  14  can be made of a strong durable plastic. If plastic is used, the blade member  14  and a sharpened cutting blade  26  can be created by a well-known injection molding operation. 
         [0024]    The handle  12  can be manufactured in either of several ways. For one, if it is to be made of a plastic material, the handle  12 , including the flanges  30   a,b  and the slit  32 , can be injection molded. For another, if the handle  12  is to be made of a metal, it can be formed into two similar halves (not shown) that can be subsequently joined together. In this case, like the blade member  14 , the metal halves for handle  12  can be stamped or die cut. The blade member  14  is then placed between the two halves prior to their being joined together. 
         [0025]    Incorporation of the blade member  14  with the handle  12  depends, primarily, on how the handle  12  has been manufactured. For an injection molded plastic handle  12 , the side  20  of blade member  14  is positioned inside the slit  32 , substantially as shown in  FIG. 1 . If the blade member  14  is made of metal, bolts  40   a  and  40   b  can then be used to secure the blade member  14  on the handle  12 . On the other hand, if the blade member  14  is plastic, and the handle  12  is plastic, they can be joined together by a thermo-bonding process. If the handle  12  is made of metal, and is formed as two halves (suggested above), the blade member  14  can be positioned between the two halves of the handle  12 . The bolts  40   a,b  can then be used to secure the blade member  14  on the handle  12 . In all cases, the handle  12  and blade member  14  can be joined together by glue. 
         [0026]    It is an important aspect of the present invention, that the cutting tool  10  be manufactured using a minimum number of constituent parts (i.e. handle  12  and blade member  14 ). Further, it is important the methods used for joining these parts together be simplified. 
         [0027]    While the particular Box Opener as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.