Abstract:
A hair clipper apparatus includes a housing and a blade assembly mountable to the housing. The blade assembly includes a first blade member having a plurality of first teeth with each said first tooth defining a first longitudinal axis of symmetry and a first primary cutting edge and a second blade member having a plurality of second teeth with each second tooth defining a second longitudinal axis of symmetry and a second primary cutting edge. Each second tooth may have a recessed segment adjacent the second primary cutting edge dimensioned to collect hair disposed between the first and second primary cutting edges. The first blade member and the second blade member are adapted for relative reciprocal movement to cut the hair collected within the recessed segment.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a hair clipper or trimmer, and, more particularly, relates to a blade assembly for a hair clipper having enhanced cutting capabilities. 
         [0003]    2. Description of the Related Art 
         [0004]    Electric hair clippers having a clipper blade assembly are known in the art. Most conventional hair clippers include a stationary blade and a reciprocating blade. The stationary blade and the reciprocating blade each have a plurality of teeth along leading edges of the blades. The clipper blade assembly may be mounted to the clipper handle such that the teeth of the stationary blade are substantially parallel to the teeth of the reciprocating blade. In this manner, oscillating the reciprocating blade with respect to the stationary blade trims hair positioned between the teeth. Examples of hair clippers are disclosed in commonly assigned U.S. Pat. No. 6,536,116 to Fung and U.S. Pat. No. 6,742,262 to Rizzuto et al., the entire contents of each disclosure being hereby incorporated by reference herein. 
       SUMMARY 
       [0005]    The present invention is directed further improvements in hair clipper or trimmer devices. In accordance with one embodiment, a hair clipper apparatus includes a housing and a blade assembly mountable to the housing. The blade assembly includes a first blade member having a plurality of first teeth with each first tooth defining a first longitudinal axis of symmetry and a first primary cutting edge, and a second blade member having a plurality of second teeth with each second tooth defining a second longitudinal axis of symmetry and a second primary cutting edge. Each second tooth may have a recessed segment adjacent the second primary cutting edge dimensioned to collect hair disposed between the first and second primary cutting edges. The first blade member and the second blade member are adapted for relative reciprocal movement to cut the hair collected within the recessed segment. 
         [0006]    Each second tooth of the second blade member may include at least two second primary cutting edges extending along the longitudinal axis and being separated by the recessed segment. In embodiments, each second tooth of the second blade member may include at least three second primary cutting edges extending along the longitudinal axis with longitudinally adjacent second primary cutting edges being separated by a recessed segment. In other embodiments, each second tooth of the second blade member may include at least two pairs of the second primary cutting edges which may be symmetrically arranged in diametrical opposed relation about the second longitudinal axis. Each first tooth of the first blade member may include a pair of first primary cutting edges symmetrically arranged in diametrical opposed relation about the first longitudinal axis. The first primary cutting edge may be dimensioned to extend at a first primary angle with respect to the first longitudinal axis and the second primary cutting edges may be dimensioned to extend at a second primary angle with respect to the second longitudinal axis different than the first primary angle. The first primary angle may be greater than the second primary angle. The first primary angle may range from about 10 degrees to about 20 degrees while the secondary primary angle may range from about 5 degrees to about 15 degrees. In embodiments, the first blade member may be a movable blade member and the second blade member may be stationary. 
         [0007]    In another embodiment, a hair clipper apparatus includes a housing and a blade assembly mountable to the housing. The blade assembly includes a first blade member having a plurality of first teeth with each first tooth defining a first longitudinal axis of symmetry and having a pair of first primary cutting edges symmetrically arranged about the first longitudinal axis, and a second blade member having a plurality of second teeth with each second tooth defining a second longitudinal axis of symmetry and having at least two pairs of second primary cutting edges symmetrically arranged about the second longitudinal axis. Longitudinally adjacent pairs of the at least two pairs of second primary cutting edges are longitudinally spaced and defining a recessed collecting zone therebetween dimensioned to gather hair. At least one of the first and second blade members are adapted for reciprocal movement relative to the other to cut hair between the first and second teeth and within the collecting zone. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Various embodiments of the present disclosure are described hereinbelow with references to the drawings, wherein: 
           [0009]      FIG. 1  is a perspective view of a hair clipper or trimmer incorporating the blade assembly of the present invention; 
           [0010]      FIG. 2  is a front plan view of the apparatus with portions of the housing removed illustrating the internal components of the housing and the blade assembly in accordance with the principles of the present disclosure; 
           [0011]      FIG. 3  is an enlarged view of the area of detail designated in  FIG. 2  illustrating the reciprocating blade member and the stationary blade member of the blade assembly; 
           [0012]      FIGS. 4-5  are front and rear plan views respectively of the reciprocating blade member of the blade assembly; 
           [0013]      FIGS. 6-7  are enlarged views of the areas of detail designated in  FIGS. 4-5 , respectively, illustrating the geometry of the teeth of the reciprocating blade member; 
           [0014]      FIGS. 8-9  are front and rear plan views respectively of the stationary blade member of the blade assembly; 
           [0015]      FIGS. 10-11  are enlarged views of the areas of detail designated in  FIGS. 8-9 , respectively, illustrating the geometry of the teeth of the stationary blade member; and 
           [0016]      FIGS. 12-14  are views illustrating alternate vertical positions of the movable blade member relative to the stationary blade member. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0017]    Referring to the drawings and, in particular,  FIG. 1 , there is shown a hair clipper in accordance with a preferred embodiment of the present invention generally represented by reference numeral  10 . Clipper  10  has housing  12 , and a motor and driver (not shown) located in the housing  12 . The motor and driver can be any conventional driver mechanism for use in a hair clipper. Housing  12  has user operating switch  14  for turning the motor “on” and “off”. A blade assembly  16  is mounted to the forward end of housing  12 . Blade assembly  16  has stationary blade  18  and reciprocating blade  20 . Reciprocating blade  20  is adapted to reciprocate relative to stationary comb blade  18  to cut hair received between the blades  18 ,  20 . A control lever  22  is provided to adjust the distance between comb blade  18  and cutter blade  20  and, thus, adjust the length or depth of cut. Further details of hair clipper  10  may be ascertained by reference to the Rizzuto &#39;262 patent. 
         [0018]    Referring now to  FIGS. 2-3 , there is illustrated the blade assembly  100  in accordance with the principles of the present disclosure, and incorporable into the hair clipper  10 . Blade assembly  100  may be mounted to housing  12  through conventional means. In one embodiment, blade assembly  100  includes first blade member  102  and second blade member  104 . First blade member  102  may be a reciprocating blade movable in the direction of directional arrows “k” as is known in the art. Second blade member may be secured relative to housing  12 , and, is thus a stationary blade member  104 . In the alternative, first blade member  102  may be stationary while second blade member  104  reciprocates. As a further alternative, first and second blade members  102 ,  104  may both reciprocate. First blade member  102  may be adjusted via control lever  22  to control the positioning of first blade member  102  relative to second blade member  104  in the direction of directional arrows “b” ( FIG. 3 ) to control the depth of cut. It is envisioned that first blade member  102  may be selectively positioned at a plurality of vertical positions relative to second blade member  104 . 
         [0019]    Referring now to  FIGS. 4-7 , in conjunction with  FIG. 3 , first blade member  102  will be discussed. First blade member  102  includes first base  106  and a plurality of first teeth  108  depending outwardly from the first base  106 . First base  106  includes means, i.e., in the form of apertures or slots  110 ,  112  for securing the first movable blade member  102  to housing  12 . Each first tooth  108  defines first longitudinal axis of symmetry “j” ( FIG. 6 ). Each first tooth  108  includes a pair of diametrically opposed primary cutting edges  114  extending along the longitudinal axis “j” towards first base  106 . First primary cutting edges  114  define an angle “t” ranging from about 10° to about 20°, possibly about 15°, relative to the longitudinal axis “j”. First primary cutting edges  114  may be generally sharp to cut hair. Each of first teeth  108  may include a planar or flat outermost edge or surface  116 , which may or may not be sharpened. Outer edge  116  facilitates the cutting action on the hair engaged by the blade assembly  100 . The front of each tooth  108  may include a raised segment  118  ( FIG. 6 ) while the rear of each tooth  108  may be substantially planar ( FIG. 7 ). 
         [0020]    First blade member  102  is adapted to reciprocate in the direction of directional arrows “k”. ( FIG. 3 ) In general, a reciprocating drive (not shown) in operative engagement with the motor of housing  12  is received within elongated drive slot  120  ( FIGS. 4 and 5 ) of first blade member  102  to effect the reciprocating action. 
         [0021]    Referring now to  FIGS. 8-11 , in conjunction with  FIG. 3 , second or stationary blade member  104  will be discussed. Second blade member  104  includes second base  122  and a plurality of second teeth  124  depending outwardly from the second base  122 . Second base  122  includes means, i.e., in the form of apertures or slots  126 ,  128  for securing the second blade member  104  to housing  12 . Each second tooth  124  defines a longitudinal axis of symmetry “m” ( FIG. 11 ). 
         [0022]    Each second tooth  124  includes at least one or more second primary cutting edges  130  disposed along the longitudinal axis “m” of each tooth  124  with adjacent second primary cutting edges  130  being in longitudinal spaced, staggered or unlated relation. Symmetrical pairs of second primary cutting edges  130  may be disposed in diametrical relation along the longitudinal axis “m”. The respective lengths “l” of each second primary cutting edge  130  of the pairs may be different or in the alternative be substantially the same. In embodiments, the respective lengths “l” are different. Second primary cutting edges  130  define an angle “y” ranging from about 5° to about 15°, possibly about 10°, relative to second longitudinal axis “m” of symmetry. In embodiments, the respective angles “y” of the pairs of second primary edges  130  may be the same. In one embodiment, the angles “y” of each pair is not equal and differs from the outermost edge  124   e  of the second tooth  124  toward the second base  122  or valley region of the second tooth  124 . In embodiments, the angle “y” may increase from the outermost edge  124   e  toward base  122  or optionally may decrease. The angle or pitch “y” may vary to fit the height or taper control of the first movable blade member  102  as controlled by the control lever  22  as discussed hereinabove. 
         [0023]    As indicated hereinabove, longitudinally adjacent second primary cutting edges  130  (including longitudinally adjacent pairs of the second primary cutting edges  130 ) are spaced from each other to define a recess or gap  132  for receiving hair particles. (see  FIGS. 3 ,  10  and  11 ) The spacing may be effected through the angle of inclination “t” of the second primary cutting edges  130  with the outermost end  130   o  of each second primary cutting edge  130  being disposed radially inward relative to the longitudinal axis “m” of each tooth  124  compared to the inner most end  130   i  of each second primary cutting edge  130 . Extending between each longitudinally adjacent second primary cutting edge  130  towards second base  120  may be surface or supplemental edge  134 . Supplemental edge  134  defines an angle “b” ranging from about 30° to about 60°, possibly about 45°. ( FIG. 11 ) The angle “b” is preferably a negative angle relative angle “y”, i.e., arranged at an opposite angular direction than angle “y”. This reverse angular arrangement of supplemental edge  134 , in combination with the inclination of each adjacent second primary cutting edges  130 , defines the contour or recess  132  for collecting hair during the cutting process. Supplemental edge  134  may be sharp to facilitate the cutting process. Each second tooth  124  may optionally include a third or intermediate edge  136  between the second primary cutting edge  130  and the supplemental edge  134 . Intermediate edge  136  also may be sharp to facilitate the cutting process. 
         [0024]    The front of each of the teeth  108  of the stationary blade member may be substantially planar while the rear has some depth or raised segments  138 ,  140  adjacent second primary cutting edge  130 , intermediate edge  136  and supplemental edge  134 . The depth of these segments facilitate grouping of hair during the cutting process. 
         [0025]    Referring back to  FIG. 3 , during use, the blade assembly  100  is positioned to engage the hair. During activation, the hair follicles “h” are collected or gathered between the first primary cutting edges  114  of the first teeth  108  and the secondary primary cutting edges  130  of the second teeth  124  and within the recess or contour  132  defined between longitudinally adjacent second primary cutting edges  130 . The first primary cutting edges  114  of the first teeth  108  of the first blade member  102  passes through the collected hair follicles “h” to effect a sickle or circular cut on the hair during the trimming process. For example, the first primary cutting edges  114  and also possibly the planar edges  116  of the first blade member  102  may contact the hair follicles “h” and, due to the respective geometries of each tooth including the gaps  132  as provided by the intersection of the second primary cutting edges  130  and the supplemental edges  134  exert a cutting or severing force in the direction of directional arrow “a” ( FIG. 3 ), which may have an arcuate or circular component of direction “c”, potentially enhancing the cutting action of the blade assembly  100 . In addition, during use, the outermost edge  116  of the first movable blade member  102  extends a bit higher or beyond the recess or contours  132  of the second stationary blade member  104  as shown in  FIG. 3  thus trapping the hair follicles “h” within the contours or undercuts  132  such that the follicles “h” are prevented from slipping out and are cut by the respective edge  114  of the first blade member  102 . As also noted above, the vertical position of first blade member  102  relative to second blade member  104  may be controlled via control lever  22  to vary the length of cut of the hair. It is envisioned that in each of the vertical positions of first blade member  102 , the outermost edge  116  of the first movable blade member  102  would extend slightly beyond the respective contour or undercut  132  along the length of each second tooth  124  whereby the hair follicles “h” would be retained or trapped within the respective contours or undercuts  132  in the manner discussed.  FIGS. 12-14  illustrate alternate vertical positions of movable blade member  102  relative to stationary blade member  104  and the respective positions of outermost edge beyond contours  132 . 
         [0026]    Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, the above description, disclosure, and figures should not be construed as limiting, but merely as exemplifications of particular embodiments. It is to be understood, therefore, that the disclosure is not limited to the precise embodiments described herein, and that various other changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the present disclosure.