Abstract:
A shaving device assembled with multiple blades having a generally planar portion and arcuate end portions in a generally parallel spaced relationship adapted for shaving curvilinear areas of a body.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/847,259 filed on Sep. 26, 2006, entitled “ERGONOMICALLY ARCUATE MULTI-BLADE RAZOR.” 
     
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to razor assemblies and, more particularly, but not by way of limitation, to an ergonomic multi-blade razor having multiple blades each with a planar portion and arcuate end portions for shaving areas of a body with improved comfort and efficiency. 
       BACKGROUND 
       [0003]    Razors have been used for centuries to facilitate the grooming of a body as well as other uses. However, grooming of the human body has been the dominant commercial area for decades. Technologically, razor designs have thus advanced dramatically as demand has grown within the last century. Razors have progressed in design from a single, linear sharpened blade to specially mounted multiple, linear blade assemblies facilitating the shaving of the face and other generally planar areas of the human body. The advantages of multi-blade assemblies are well known. Typically, multi-blade razor structures include a plastic housing that supports the multiple linear blades in a staggered, generally parallel relationship, whereby the skin surface shaved by the passage of the first blade is additionally shaved by the passage of the second and/or multiple other blades resulting in a more efficient shaving process. One of the key aspects in multiple blade assemblies is the mounting configuration and the safety aspect for protecting the skin of the user from nicks, scrapes, and scratches by exposing only the portion of the linear blade necessary for grooming. 
         [0004]    Other improvements in razor blade designs have included means for mounting single razor blades in a housing imparting a bending to the blade to thereby facilitate the presentation of an arcuate single blade within a safety blade housing for shaving sloped areas of the human body, such as under arm and groin regions which are typically non-planar in formation as seen in U.S. Pat. No. 5,208,982 to Ferruzza. The advantage of such an arcuate assembly is readily apparent by virtue of the fact that some areas of the human anatomy are not substantially planar and are often considered required grooming areas. These areas are typically sensitive to sharp razor blade exposure. Therefore, any improvement in razor designs that may eliminate the danger of cuts and/or nicks from the shaving procedure and/or improving the efficiency of the shaving procedure in such delicate areas of a body, would be a marked advantage. Further other improvements in razor design include safety razor blade units including a plurality of blades with parallel sharpened edges as seen in U.S. Pat. No. 6,212,777 to Gilder et al. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention relates to improvements in shaving technology. More particularly, one aspect of the invention incorporates a shaving device assembled with multiple blades having a planar portion and arcuate end portions in a generally parallel spaced relationship adapted for shaving curvilinear areas of a body. To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. 
     
     
       DESCRIPTION OF THE DRAWINGS 
         [0006]    A more complete understanding of the present invention may be obtained by reference to the following Detailed Description, when taken in conjunction with the accompanying Drawings, wherein: 
           [0007]      FIG. 1  is a front perspective view of an embodiment of the present invention; 
           [0008]      FIG. 2  is a perspective view of the razor head of  FIG. 1  illustrating various constructional aspects thereof in accordance with the principles of the present invention; 
           [0009]      FIG. 3  is an enlarged side elevation view of the shaver head of  FIG. 1  illustrating additional construction on features thereof; and 
           [0010]      FIG. 4  is an enlarged, fragmentary perspective view of an end region of the shaver head of  FIG. 1  illustrating other constructional aspects thereof in accordance with the principles of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    The present invention will now be described more fully with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be constructed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
         [0012]    Referring now to  FIG. 1 , there is shown a safety razor  10  constructed in accordance with the principles of the present invention. The safety razor  10  comprises a razor head  20  disposed at the end of a handle  28 , said razor head  20  having a plurality of blades  12 ,  14 ,  16 , and  18  disposed in a generally parallel spaced relationship. The razor head  20  has a generally planar intermediate portion  22  and two arcuate end portions  24  and  26 . More specifically, the arcuate portions  24  and  26  define a positive (with reference to the exposed edges of the blades) curvature of the plurality of blades  12 ,  14 ,  16  and  18 , wherein curvature is the ratio of the change in the angle of a tangent that moves over a given arc to the length of the arc. A positive curvature is generally associated with a convex shape and a negative curvature is associated with a concave shape. Viewing safety razor  20  in two dimensions with intermediate portion  22  lying along the abscissa of a Cartesian coordinate system, the positive curvature of arcuate portions  24  and  26  can be seen in  FIG. 1 . The intermediate portion  22  and arcuate portions  24  and  26  are adapted to position blades  12 ,  14 ,  16 , and  18  with respect to each other and are more clearly illustrated in  FIG. 3  discussed herein below. 
         [0013]    In an embodiment of the present invention, razor head  20  is permanently attached to a handle  28 . Said razor head  20  can be in a fixed position on the handle  28  or pivotable about an axis parallel to the blade edges. In a further embodiment of the present invention, razor head  20  is in the form of a detachable cartridge without a housing, but only blade alignment guides, said cartridge intended to be replaced when the blade edges have become dulled. In said further embodiment, detachable razor head  20  can be in a fixed position on the handle  28  or can be pivotable about an axis parallel to the blade edges. 
         [0014]    Safety razor  10  includes several varying designs. It can be designed as a single piece disposable razor having a hollow plastic handle  28  with razor head  20  holding blades  12 ,  14 ,  16  and  18 . As noted above, safety razor  10  can also be designed to accept refillable cartridges holding blades  12 ,  14 ,  16  and  18 . This latter design, in which the razor handle is not disposable, but the cartridge is disposable, can include other premium features such as a soft grip handle and a moisturizer container disposed to dispense moisturizer through the handle to an area proximate the blades  12 ,  14 ,  16  and  18 . 
         [0015]    Razor blades  12 ,  14 ,  16  and  18  are typically made of a corrosion resistant steel alloy which is hard enough to allow each blade to hold its shape, yet malleable enough to allow it to be formed into its arcuate positions. Preferably, said steel alloy is a carbide steel made with a tungsten-carbon compound. Said compound may include primarily iron with a combination of carbon, silicon, manganese, chromium and molybdenum. 
         [0016]    The plastic portions of safety razor  10  are typically molded from a number of different plastic resins including polystyrene, polypropylene, and phenyleneoxide based resins as well as elastomeric compounds. These resins begin in pellet form and are melted and molded using extrusion and injection molding techniques. Safety razor  10  further includes components that hold the blades in place and springs or other release mechanisms which facilitate changing of blade cartridges. 
         [0017]    The manufacture of blades  12 ,  14 ,  16  and  18  requires the mixing and melting of the above referenced steel alloy material. The mixture first undergoes an annealing process wherein the steel alloy is heated to a temperature of about 2,000° F., then quenched in water to a temperature of about 100° F. to harden it. The steel is then tempered at a temperature of between 500 and 750° F. Blades  12 ,  14 ,  16  and  18  are then die stamped to form a planar shape and bent using a metal bending tool to form their respective arcuate shape. The cutting surface of intermediate portion  22  of each blade is about 2 to 4 centimeters by 0.75 to 3 millimeters. The arcuate cutting surfaces of end portions  24  and  26  of each blade (beginning at the point where the curvature of the arcuate portions begin) are in the range of 0.75 to 1.5 centimeters by 0.75 to 3 millimeters. Further, the distance from the edge of each blade to the edge of its adjacent blade is in the range of 0.5 to 1.75 mm. 
         [0018]    Referring now to  FIG. 2 , intermediate portion  22  and arcuate portions  24  and  26  are shown in more detail. A series of blade alignment guides  30  are shown placed at predetermined intervals along intermediate portion  22  and arcuate portions  24  and  26  for receipt and positioning of razor blades  12 ,  14 ,  16 , and  18  is in a generally parallel spaced relationship. Each blade alignment guide is held in place by the structure formed by the intermediate portion  22  and the arcuate portions  24  and  26 . 
         [0019]    Referring now to  FIG. 3 , razor alignment guide  30  is shown with angled slots  32 ,  34 ,  36 , and  38  adapted for the receipt and positioning of razor blades  12 ,  14 ,  16 , and  18 . The angled slots  32 ,  34 ,  36 , and  38  are formed at a predetermined angle in accordance with the principles of the design. For example, assume solely for purposes of illustration that intermediate portion  22  of each blade  12 ,  14 ,  16  and  18  have the same three dimensional sizes of 3.5 cm by 0.1 mm by 1 mm. Further assume that a corner of blade  12  is placed at the origin 0, 0, 0. With the forgoing length x, height y, and width z, it would extend from the origin to x, y, z coordinates of 3.5 cm, 0.1 mm, −1 mm (e.g., the front cutting edge of blade  12  is lying flat on the x-axis). Then the extent of intermediate portion  22  of blade  14  would be located at, e.g., 3.5 cm, 0.10 mm, −5 mm; the extent of intermediate portion  22  of blade  16  would be located at, e.g., 3.5 cm, 0.20 mm, −10 mm; and the extent of intermediate portion  22  of blade  18  would be located at, e.g., 3.5 cm, 0.30 mm, −15 mm. The arcuate portions of each of the blades would be similarly spaced from the adjacent blades. 
         [0020]    Positioned between slots  32 ,  34 , and  36  and after slot  38  are decks  42 ,  44 ,  46 , and  48  respectively. Decks  42 ,  44 ,  46 , and  48  are adapted to reduce the instances where a user might cut his or her skin with blades  12 ,  14 ,  16 , and  18 . A leading comfort pad  52  and a trailing comfort pad  54  further help reduce the instances a user might cut his or her skin with blades  12 ,  14 ,  16 , and  18 . Said comfort pads can include lubricating strips and water activated moisturizers. 
         [0021]      FIG. 4  depicts another embodiment of the present invention wherein the intermediate portion  22  and the end portions  24  and  26  (only  26  is shown) of the razor have a higher degree of curvature. 
         [0022]    The embodiments shown and described above are only exemplary. Even though numerous characteristics and advantages of the preferred embodiment of the present invention have been set forth in the foregoing description together with details of the invention, the disclosure is illustrative only and changes may be made within the principles of the invention to the full extent indicated by the broad general meaning of the terms used in the attached claims.