Patent Publication Number: US-9833914-B2

Title: Hair clipper

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The application is based upon and claims the benefit of priority of Japanese Patent Application No. 2012-087790, filed on Apr. 6, 2012, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to hair clippers, and particularly to a hair clipper with a clipping height adjusting function. 
     BACKGROUND ART 
     In the past, there has been provided an electric hair clipper configured to cut human head hairs by use of a comb-like fixed blade and a comb-like movable blade reciprocated relative to the fixed blade. For example, such an electric hair clipper is configured to vary a clipping height by means of attaching a specific attachment for adjusting the clipping height. 
     The aforementioned attachment has a comb-like member covering a blade part of the hair clipper, and forms a space between the blade part and a human skin. The clipping height can be varied with a change in an attaching position of the attachment. 
     In these kinds of hair clippers, a latching mechanism may be adopted for changing the attaching position of the attachment. With regard to a hair clipper with such a latching mechanism, when the attachment is pressed against one&#39;s skin, a position of the attachment may be changed. Such a change in the position of the attachment causes a change in the clipping height. 
     JP 1-214388 A discloses a hair clipper including a main body incorporating a motor therein and a handle ring attached to the main body in such a manner to be allowed to rotate about an axis and to slide in an axial direction. As for this hair clipper, a pin-shaped protrusion protruded from an outer periphery of the main body is engaged with a spiral cam groove formed in an inner periphery of the handle ring, and an attachment with a comb member is linked to an apical end of the handle ring. When the handle ring is rotated, engagement between the spiral cam groove and the protrusion causes the handle ring to move along the axial direction. As a result, the position of the attachment is varied. 
     In this situation, since a rotational motion is converted into a motion in the axial direction by means of the spiral cam groove and the protrusion, pressing the attachment does not cause a great undesirable backward movement of the attachment. Thus, the clipping height is not greatly changed. 
     However, the spiral cam groove has an inner surface along its lengthwise direction, and the inner surface is an inclined surface oblique to the axial direction (sliding direction) of the handle ring. Hence, the attachment may be displaced due to a load caused by pressing the attachment against one&#39;s skin surface, or due to vibration of the motor. Further, the attachment may be inclined when a pressing direction of the attachment against one&#39;s skin is not approximately parallel to a lengthwise direction of the main body. Such displacement or inclination of the attachment may deteriorate an accuracy of the clipping height. 
     SUMMARY OF INVENTION 
     In view of the above insufficiency, the present invention has aimed to propose a hair clipper capable of facilitating adjusting a clipping height to a desired height and of keeping the adjusted clipping height constant precisely. 
     The hair clipper of the first aspect in accordance with the present invention includes a blade block, and an adjusting device for adjusting a clipping height of the blade block. The adjusting device includes an attachment, a handle ring, and a connection mechanism. The attachment is disposed to overlap with the blade block and to be allowed to move in a predetermined moving direction relative to the blade block. The handle ring is formed into a circular hollow cylindrical shape and is disposed to be rotated around a rotation axis extending along the moving direction. The connection mechanism connects the handle ring to the attachment such that the attachment is moved with rotation of the handle ring. The clipping height is determined by a relative position of the attachment to the blade block in the moving direction. The connection mechanism includes a cam groove provided to one of the attachment and the handle ring, and a linking pin provided to the other of the attachment and the handle ring, and placed inside the cam groove so as to be moved along the cam groove. The cam groove includes a first side and a second side opposite to each other in the moving direction. The first side includes plural step parts formed in different positions in the moving direction respectively associated with the different clipping heights, and a slope part configured to connect the step parts. The step parts extend in a direction normal to the moving direction. 
     As for the hair clipper of the second aspect in accordance with the present invention, in addition to the first aspect, the blade block is provided with a blade section at its end in an apical direction extending along the moving direction. The step part is defined as a surface directed to the apical direction. 
     As for the hair clipper of the third aspect in accordance with the present invention, in addition to the second aspect, the attachment includes a comb part protruding along the apical direction. The clipping height is determined by a distance between an apical end of the blade section and an apical end of the comb part in the moving direction. 
     As for the hair clipper of the fourth aspect in accordance with the present invention, in addition to any one of the first to third aspects, the second side includes plural second step parts respectively opposite to the plural step parts, and a second slope part configured to connect the second step parts. The cam groove is designed to hold the linking pin between the step part and the second step part opposite thereto. 
     As for the hair clipper of the fifth aspect in accordance with the present invention, in addition to the fourth aspect, the second step parts are parallel to the respective opposite step parts. 
     As for the hair clipper of the sixth aspect in accordance with the present invention, in addition to the fifth aspect, a distance between the step part and the second step part opposite thereto is equal to a dimension of the linking pin in the moving direction. 
     As for the hair clipper of the seventh aspect in accordance with the present invention, in addition to any one of the first to sixth aspects, the connection mechanism includes a plurality of the linking pins. 
     As for the hair clipper of the eighth aspect in accordance with the present invention, in addition to the seventh aspect, the plurality of the linking pins are arranged so as to be respectively positioned at the mutual different step parts when one of the linking pins is positioned at one of the step parts. 
     As for the hair clipper of the ninth aspect in accordance with the present invention, in addition to the seventh or eighth aspect, the connection mechanism includes a plurality of the cam grooves respectively corresponding to the plurality of the linking pins. 
     As for the hair clipper of the tenth aspect in accordance with the present invention, in addition to the ninth aspect, the cam grooves have mutually different widths. The linking pins are designed to be fitted into the respectively corresponding cam grooves. 
     As for the hair clipper of the eleventh aspect in accordance with the present invention, in addition to any one of the first to tenth aspects, the attachment includes an attachment part serving as a part overlapping with the blade block, and a slider part serving as a part attached to the handle ring. The attachment part is detachably attached to the slider part. 
     As for the hair clipper of the twelfth aspect in accordance with the present invention, in addition to any one of the first to eleventh aspects, the blade block includes two comb-like blades arranged to overlap with each other. 
     As for the hair clipper of the thirteenth aspect in accordance with the present invention, in addition to the twelfth aspect, the hair clipper further includes a main body configured to hold the blade block. The attachment and the handle ring are attached to the main body. 
     As for the hair clipper of the fourteenth aspect in accordance with the present invention, in addition to the thirteenth aspect, the hair clipper further includes a driving device housed in the main body. The driving device is configured to reciprocate one of the two comb-like blades relative to the other of the two comb-like blades in a predetermined reciprocation direction. The moving direction is defined as a direction crossing the reciprocation direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view illustrating a primary part of a hair clipper of one embodiment in accordance with the present invention, 
         FIG. 2  is a view illustrating a primary part of the hair clipper, 
         FIG. 3  is a view illustrating the hair clipper without an attachment, 
         FIG. 4  is a view illustrating the hair clipper without the attachment and a blade block, 
         FIG. 5  is a perspective sectional view illustrating the hair clipper, 
         FIG. 6  is a partial expanded view of  FIG. 5 , 
         FIG. 7  is a perspective view illustrating the attachment of the hair clipper, 
         FIG. 8  is a perspective view illustrating an attachment part of the hair clipper, 
         FIG. 9  is a perspective view illustrating a slider part of the hair clipper, 
         FIG. 10  is a sectional view illustrating the slider part and a handle ring of the hair clipper, 
         FIG. 11  is a sectional view illustrating the slider part and the handle ring of the hair clipper, 
         FIG. 12  is a view illustrating a position relation between the slider part and the handle ring of the hair clipper, 
         FIG. 13  is a view illustrating a position relation between the blade block and the attachment part of the hair clipper, 
         FIG. 14  is a view illustrating a position relation between the slider part and the handle ring of the hair clipper, 
         FIG. 15  is a view illustrating a position relation between the blade block and the attachment part of the hair clipper, 
         FIG. 16  is a view illustrating a position relation between the slider part and the handle ring of the hair clipper, and 
         FIG. 17  is a view illustrating a position relation between the blade block and the attachment part of the hair clipper. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     As shown in  FIGS. 3 to 6 , the hair clipper (electric hair clipper) of one embodiment of the present invention includes a main body  1 , and a head  3 . The main body  1  incorporates a motor  10  therein. Arranged at a part of the main body  1  close to a front end thereof is a handle ring  4  which is formed into a circular hollow cylindrical shape. The head  3  is detachably coupled to the front end of the main body  1 . The head  3  includes a cover block  31  arranged to cover the front end of the main body  1 , and a blade block  32  detachably attached to the cover block  31 . As shown in  FIGS. 3 and 4 , the main body  1  is equipped with a power switch  11 . Note that, the cover block  31  and the power switch  11  are optional. 
     The blade block  32  includes a fixed blade provided with a comb-like blade portion and a movable blade provided with a comb-like blade portion in a similar manner as the fixed blade. The movable blade is engaged with an eccentric shaft  15  which is placed on a front surface of the main body  1  and is connected to an output axle of the motor  10 . This engagement allows the movable blade to reciprocate in contact with the fixed blade in response to rotation of the motor  10 . 
     As mentioned above, the hair clipper of the present embodiment includes the blade block  32 , the main body  1 , and the driving device (motor)  10 . 
     The blade block  32  is provided with a blade section  320  at its end in an apical direction. The apical direction is defined as a direction extending along a direction of a central axis of the main body  1 . The blade section  320  includes two comb-like blades (fixed and movable blades)  321  and  322  arranged to overlap with each other. The blade block  32  is attached to the end in the apical direction of the body  1 . 
     The driving device  10  is configured to reciprocate one (e.g., the fixed blade) of the two comb-like blades  321  and  322  relative to the other (e.g., the movable blade) of the two comb-like blades  321  and  322  in a predetermined reciprocation direction. For example, the reciprocation direction is a direction crossing the direction of the central axis of the main body  1  (in this embodiment, the reciprocation direction is a direction normal to the direction of the central axis of the main body  1 ). 
     The hair clipper of the present embodiment further includes an adjusting device  7  for adjusting a clipping height (length of a remaining hair) of the blade block  32 . As shown in  FIGS. 5, 13, 15, and 17 , the adjusting device  7  includes an attachment  5  and the handle ring  4 . Additionally, as shown in  FIGS. 10 and 11 , the adjusting device  7  includes a connection mechanism connecting the handle ring  4  to the attachment  5 . 
     The attachment  5  is used to determine the clipping height. The attachment  5  is disposed to overlap with the blade block  32  and to be allowed to move in a predetermined moving direction relative to the blade block  32 . In the present embodiment, the attachment  5  is attached to the main body  1  movably in the moving direction. For example, the predetermined direction is identical to the direction (upward and downward direction in  FIG. 11 ) of the central axis of the main body  1 . In brief, the attachment  5  is attached to the main body  1  so as to be allowed to move along the direction of the central axis of the main body  1 . 
     As shown in  FIG. 7 , the attachment  5  for adjusting the clipping height attached to this hair clipper includes a slider part  51  formed into a ring shape and an attachment part  55 . 
     As shown in  FIGS. 9 to 11 , the slider part  51  includes a body portion  510  formed into a circular hollow cylindrical shape. The body portion  510  is formed to have dimensions such that the body portion  510  can be placed inside the handle ring  4 . The slider part  51  is provided with a pair of arm portions  52  protruded from one end (upper end in  FIG. 9 ) in an axial direction of the body portion  510  along the axial direction. Each of the arm portions  52  is provided at its apex with a hooking portion  53  used for connection between the attachment part  55  and the slider part  51 . 
     Further, formed in an outer face (outer periphery) of the body portion  510  are two cam grooves  6 A and  6 B. The cam groove  6 A,  6 B is used for connection between the handle ring  4  and the slider part  51 . 
     As mentioned above, the slider part  51  is disposed inside the handle ring  4 , and is provided at its outer periphery with the two cam grooves  6 A and  6 B, and is provided with the pair of the arm portions  52  and  52  extending to an apical side thereof. 
     The attachment part  55  includes a cap  551  designed to cover the blade block  32 . The cap  551  is provided at its one face (front face) with an opening  59  exposing the blade section  320  of the blade block  32 . The attachment part  55  includes a plurality of comb parts  56  protruding forward from a vicinity of the opening  59 . The comb part  56  serves to adjust the clipping height. 
     In brief, in the hair clipper of the present embodiment, the clipping height is determined by a relative position of the attachment  5  to the blade block  32  in the moving direction. Especially, the clipping height is determined by a distance between an apical end of the blade section  320  and an apical end of the comb part  56  in the moving direction. 
     The attachment part  55  further includes a pair of linking arms  57  protruding rearward from the cap  551 . Each of the linking arms  57  is provided at its apex with an engagement portion  58  used for connection between the attachment part  55  and the slider part  51 . The engagement portion  58  and the hooking portion  53  are designed to engage with each other. 
     As mentioned above, the attachment part  55  has the comb part  56  overlapping with the blade section  320  at the apex of the blade block  32 . The attachment part  55  is provided at ends of the paired linking arms  57  and  57  extending rearward with the engagement portions  58  and  58  which are engaged with the hooking portions  53  and  53  of the arm portions  52  and  52  to be connected to the slider part  51 . Besides, the arm portions  52  and  52  are positioned inside through holes  35  provided to the cover block  31  of the head  3  and are linked to the linking arms  57  inside the through holes  35 , respectively. 
     As mentioned above, the attachment  5  includes the attachment part  55  serving as a part overlapping with the blade block  32 , and the slider part  51  serving as a part attached to the handle ring  4 . The attachment part  55  is detachably attached to the slider part  51 . 
     In the hair clipper of the present embodiment, the clipping height is determined by the relative position of the attachment  5  to the blade block  32  in the moving direction. Especially, in the present embodiment, the clipping height is determined by a distance between the blade section  320  and the comb part  56 . 
     As shown in  FIGS. 10 and 11 , the handle ring  4  is formed into a circular hollow cylindrical shape. The handle ring  4  is disposed to be rotated around a rotation axis (upward and downward direction in  FIG. 11 ) extending along the moving direction. In the present embodiment, the handle ring  4  is attached to the main body  1  so as to rotate around the rotation axis. The moving direction is defined as a direction extending along the direction of the central axis of the main body  1 . Consequently, the handle ring  4  is attached to the main body  1  so as to rotate around the central axis of the main body  1 . 
     As shown in  FIG. 10 , the slider part  51  of the attachment  5  is placed inside the handle ring  4 . Formed in an inner face (inner periphery) of the handle ring  4  are two linking pins  41 A and  41 B. The linking pin  41 A,  41 B serves to connect the handle ring  4  to the slider part  51 . 
     As mentioned above, the handle ring  4  encircling the slider part  51  of the attachment  5  is disposed to be allowed to rotate around the axis of the main body  1 . The handle ring  4  is provided at its inner periphery (inner peripheral surface) with the two linking pins  41 A and  41 B. One linking pin  41 A is engaged with one (the cam groove  6 A) of the two cam grooves  6 A and  6 B formed in the outer periphery (outer peripheral surface) of the slider part  51 , and the other linking pin  41 B is engaged with the other cam groove  6 B. 
     Consequently, in the present embodiment, the linking pin  41 A,  41 B and the cam groove  6 A,  6 B constitute the connection mechanism connecting the handle ring  4  to the attachment  5  such that the attachment  5  is moved with rotation of the handle ring  4 . In other words, the connection mechanism includes the cam groove  6 A,  6 B provided to the attachment  5  and the linking pin  41 A,  41 B provided to the handle ring  4 . In the present embodiment, the connection mechanism includes the plurality of (two) cam grooves  6 A and  6 B and the plurality of (two) linking pin  41 A and  41 B. 
     The linking pin  41 A is placed inside the cam groove  6 A so as to be moved along the cam groove  6 A. The linking pin  41 B is placed inside the cam groove  6 B so as to be moved along the cam groove  6 B. For example, the linking pin  41 A,  41 B is formed into a true circular solid cylindrical shape. The two linking pins  41 A and  41 B have mutually different dimensions in the moving direction. In other words, the two linking pins  41 A and  41 B have mutually different diameters. 
     As shown in  FIGS. 1 and 2 , the cam grooves  6 A and  6 B extend in a direction across the moving direction (upward and downward direction in  FIG. 1 ). The cam groove  6 A is associated with the linking pin  41 A and the cam groove  6 B is associated with the linking pin  41 B. 
     Each cam groove  6 A,  6 B includes a first side  601 A,  601 B and a second side  602 A,  602 B which are opposite to each other in the moving direction. The first side  601 A,  601 B is defined as a surface far from the blade block  32 , and the second side  602 A,  602 B is defined as a surface close to the blade block  32 . 
     The first side  601 A,  601 B includes plural (first) step parts  611 A,  611 B extending in a direction normal to the moving direction, and a (first) slope part  621 A,  621 B configured to connect the (adjacent) step parts  61  ( 611 ) (to each other). In the present embodiment, the first side  601 A,  601 B includes a plurality of the step parts  611 A,  611 B and a plurality of the slope parts  621 A,  621 B. 
     The step parts  611 A,  611 B are formed in different positions in the moving direction respectively associated with the different clipping heights. The plural step parts  611 A,  611 B include the step part  6111 A,  6111 B (see  FIG. 1 ) associated with the lowest clipping height and the step part  6112 A,  6112 B (see  FIG. 16 ) associated with the highest clipping height. The step part  6111 A,  6111 B associated with the lowest clipping height is one of the plural step parts  611 A,  611 B and is closest to the blade block  32 . The step part  6112 A,  6112 B associated with the highest clipping height is one of the plural step parts  611 A,  611 B and is farthest from the blade block  32 . 
     Further, the step parts  611 A,  611 B are formed in different positions in a circumferential direction of the slider part  51 . In the present embodiment, the plural step parts  611 A,  611 B are flat surfaces orthogonal to the moving direction, and are parallel to each other. The step parts  611 A,  611 B are surfaces which are directed to the side of the blade block  32  (i.e., the apical direction). 
     Each of the slope parts  621 A,  621 B is configured to connect the adjacent step parts  611 A,  611 B to each other. In the present embodiment, the plural slope parts  621 A,  621 B are flat surfaces across the moving direction, and are parallel to each other. 
     The second side  602 A,  602 B includes plural (second) step parts  612 A,  612 B respectively opposite to the plural step parts  611 A,  611 B, and a (second) slope part  622 A,  622 B configured to connect the (adjacent) second step parts  612 A,  612 B (to each other). In the present embodiment, the second side  602 A,  602 B includes a plurality of the second step parts  612 A,  612 B and a plurality of the second slope parts  622 A,  622 B. 
     The second step parts  612 A,  612 B are parallel to respective opposite step parts  611 A,  611 B. In other words, the second step parts  612 A,  612 B are formed in different positions in the moving direction respectively associated with the different clipping heights. Further, the second step parts  611 A,  611 B are formed in different positions in the circumferential direction of the slider part  51 . In the present embodiment, the plural second step parts  612 A,  612 B are flat surfaces orthogonal to the moving direction, and are parallel to each other. 
     Each of the second slope parts  622 A,  622 B is configured to connect the adjacent second step parts  612 A,  612 B to each other. In the present embodiment, the plural second slope parts  622 A,  622 B are flat surfaces across the moving direction, and are parallel to each other. 
     With respect to the cam groove  6 A,  6 B, the step part  611 A,  611 B and the second step part  612 A,  612 B opposite to this step part  611 A,  611 B constitute a holding groove determining the clipping height. In the present embodiment, each of the step part  611 A,  611 B and the second step part  612 A,  612 B is a flat surface perpendicular to the moving direction. Thus, each holding groove extends orthogonal to the moving direction. In addition, each of the holding grooves has its opposite inner sides parallel to each other. Further, the slope part  621 A,  621 B and the second slope part  622 A,  622 B opposite to this slope part  621 A,  621 B constitute a connection groove configured to connect the (adjacent) holding grooves (to each other). 
     Consequently, the cam groove  6 A,  6 B is considered as being constituted by the plural holding grooves associated with respective different clipping heights and the connection grooves configured to connect holding grooves. 
     The plural holding grooves have the same width. The width of the holding groove is equal to a distance between the step part  611 A,  611 B and the second step part  612 A,  612 B opposite to this step part  611 A,  611 B (a distance between the opposite inner sides of holding groove). The width of the holding groove is defined as a width of the cam groove at the step part  611 A,  611 B of the first side  601 A,  601 B (or the second step part  612 A,  612 B of the second side  602 A,  602 B). 
     In the present embodiment, the width of the holding groove is identical to the dimension of the linking pin  41 A,  41 B in the moving direction (i.e., the diameter of the linking pin  41 A,  41 B). For example, the width of the holding groove of the cam groove  6 A is identical to the dimension of the linking pin  41 A in the moving direction (i.e., the diameter of the linking pin  41 A). Further, the width of the holding groove of the cam groove  6 B is identical to the dimension of the linking pin  41 B in the moving direction (i.e., the diameter of the linking pin  41 B). 
     The plural connection grooves have the same width. The width of the connection groove is equal to a distance between the slope part  621 A,  621 B and the second slope part  622 A,  622 B opposite to this slope part  621 A,  621 B. The width of the connection groove is defined as a width of the cam groove at the slope part  621 A,  621 B of the first side  601 A,  601 B (or the second slope part  622 A,  622 B of the second side  602 A,  602 B). In the present embodiment, the width of the connection groove is identical to the dimension of linking pin  41 A,  41 B in the moving direction (i.e., the diameter of the linking pin  41 A,  41 B). For example, the width of the connection groove of the cam groove  6 A is identical to the dimension of linking pin  41 A in the moving direction (i.e., the diameter of the linking pin  41 A). Further, the width of the connection groove of the cam groove  6 B is identical to the dimension of linking pin  41 B in the moving direction (i.e., the diameter of the linking pin  41 B). 
     In brief, as for the present embodiment, the cam groove  6 A,  6 B has the width identical to the dimension (diameter) of the corresponding linking pin  41 A,  41 B in the moving direction. In other words, the linking pins  41 A and  41 B are designed to be fitted into the respectively corresponding cam grooves  6 A and  6 B. 
     Hence, the linking pin  41 A is positioned in the holding groove in such a manner to be in contact with the opposite inner sides (the step part  611 A and the second step part  612 A) of the holding groove of the cam groove  6 A. Additionally, the linking pin  41 B is positioned in the holding groove in such a manner to be in contact with the opposite inner sides (the step part  611 B and the second step part  612 B) of the holding groove of the cam groove  6 B. Consequently, the attachment  5  is prevented from moving in the moving direction. 
     In the present embodiment, as shown in  FIG. 10 , the two linking pins  41 A and  41 B face each other in a direction (upward and downward direction in  FIG. 10 ) normal to a direction of a central axis of the handle ring  4 . Thus, the two linking pins  41 A and  41 B are arranged so as to be respectively positioned at the mutual different step parts  611 A,  612 A,  611 B,  612 B when one of the linking pins  41 A and  41 B is positioned at one of the step parts  611 A,  612 A,  611 B,  612 B. As for the present embodiment, when the linking pin  41 A is positioned at any one of the step parts  611 A,  612 A,  611 B,  612 B of the cam groove  6 A, the linking pin  41 B is positioned at any one of the step parts  611 A,  612 A,  611 B,  612 B of the cam groove  6 B. 
     The two cam grooves  6 A and  6 B provided to the slider part  51  are spiral and are inclined relative to an axial direction of the handle ring  4 . Thus, the slider part  51  moves forward or rearward with rotation of the handle ring  4  around the axis thereof. According to such rotation, the attachment part  55  connected to the slider part  51  also moves forward or rearward. 
     Such forward and rearward movement of the attachment part  55  varies an interval between the blade section  320  of the blade block  32  and the comb part  56  of the attachment part  55 . Thus, in a situation where hairs are cut by the blade block  32  while the comb part  56  is in contact with one&#39;s skin, it is possible to adjust the clipping height. 
       FIG. 12  shows a positional relation between the slider part  51  and the handle ring  4  in a situation where the clipping height is the lowest level. When the clipping height is the lowest level, as shown in  FIGS. 1 and 12 , the linking pins  41 A and  41 B are positioned at the step parts  6111 A and  6111 B of the respective corresponding cam grooves  6 A and  6 B. In this situation, as shown in  FIG. 13 , the distance between the apical (front) end of the blade block  32  (i.e., the apical end of the blade section  320 ) and the apical (front) end of the attachment part  55  (i.e., the apical end of the comb part  56 ) in the moving direction is the shortest. Hence, the clipping height becomes the lowest level. 
     To increase the clipping height, the handle ring  4  is rotated such that, as shown in  FIG. 14 , the linking pin  41 A,  41 B is moved from the step part  611 A,  611 B corresponding to the lowest clipping height to the step part  611 A,  611 B corresponding to the clipping height higher than that of the step part  6111 A,  6111 B. In the present embodiment, the handle ring  4  is rotated along a clockwise direction in  FIG. 11  (a direction represented by an arrow  100  in  FIG. 15 ). 
     In this situation, as shown in  FIG. 15 , the distance between the apical (front) end of the blade block  32  (i.e., the apical end of the blade section  320 ) and the apical (front) end of the attachment part  55  (i.e., the apical end of the comb part  56 ) in the moving direction is increased, and the clipping height is also increased. 
     When the handle ring  4  is further rotated, finally, the linking pin  41 A,  41 B reaches the step part  6112 A,  6112 B corresponding to the highest clipping height.  FIG. 16  shows a positional relation between the slider part  51  and the handle ring  4  in a situation where the clipping height is the highest level. When the clipping height is the highest level, as shown in  FIG. 16 , the linking pins  41 A and  41 B are positioned at the step parts  6112 A and  6112 B of the respective corresponding cam grooves  6 A and  6 B. In this situation, as shown in  FIG. 17 , the distance between the apical (front) end of the blade block  32  (i.e., the apical end of the blade section  320 ) and the apical (front) end of the attachment part  55  (i.e., the apical end of the comb part  56 ) in the moving direction is the longest. Hence, the clipping height becomes the highest level. 
     In this embodiment, a pair of lengthwise sides (the first side and the second side)  601 A,  601 B and  602 A,  602 B in the axial direction of each of the cam grooves  6 A,  6 B is formed into a stepwise shape. 
     In other words, as shown in  FIG. 9 , the lengthwise side  601 A,  601 B,  602 A,  602 B includes the step parts  611 A,  612 A,  611 B,  612 B substantially normal to the axial direction (sliding direction of the slider part  51 ) of the handle ring  4  and the slope parts  621 A,  622 A,  621 B,  622 B connecting the next step parts  611 A,  612 A,  611 B,  612 B formed at different positions in the axial direction. 
     As shown in  FIGS. 1 and 2 , when the linking pin  41 A,  41 B which is circular (or elliptical, or polygonal) in cross section is positioned between any one of the step parts  611 A,  611 B of one lengthwise side (first side)  601 A,  601 B of the cam groove  6 A,  6 B and the step parts  612 A,  612 B of the other lengthwise side (second side)  602 A,  602 B arranged opposite to this step part  611 A,  611 B in the axial direction, the clipping height is held at a desired level. When the linking pin  41 A,  41 B is moved to a different pair of the lengthwise sides  601 A,  601 B through a path between the slope parts  621 A,  621 B and  622 A,  622 B of the paired lengthwise sides  601 A,  601 B and  602 A,  602 B, the clipping height becomes a different level. 
     Note that, in the illustrated instance, the clipping height is adjustable in twenty levels with an interval of 0.5 mm. Based on the assumption that the hair clipper is used for clipping not only hairs but also whiskers, the hair clipper is designed such that the clipping height can be adjusted finely. 
     The paired lengthwise sides  601 A,  601 B and  602 A,  602 B of the cam groove  6 A,  6 B are formed into stepwise shapes. Thus, when the clipping height is set, the linking pin  41 A,  41 B is positioned between the step parts  611 A,  611 B and  612 A,  612 B opposite to each other in the axial direction. 
     According to this configuration, a clearance in the sliding direction (moving direction) of the slider part  51  is quite small. Further, even when the handle ring  4  is slightly moved in the rotation direction, the linking pin  41 A,  41 B is held between the opposite step parts  611 A,  611 B and  612 A,  612 B. Hence, a force to cause movement of the slider part  51  in the axial direction does not occur. 
     To reduce a possibility that the handle ring  4  is rotated unexpectedly, the main body  1  is provided at its sides with extension parts  12  and  12  designed to cover the outer periphery of the handle ring  4  to reduce an exposed area of the handle ring  4 . 
     Besides, in the present embodiment, the linking pin  41 A,  41 B is provided to the handle ring  4  and the cam groove  6 A,  6 B is provided to the slider part  51 . The cam groove  6 A,  6 B may be provided to the inner periphery of the handle ring  4  and the linking pin  41 A,  41 B may be provided to the outer periphery of the slider part  51 . In other words, it is sufficient that the connection mechanism includes the cam groove  6 A,  6 B provided to one of the attachment  5  and the handle ring  4  and the linking pin  41 A,  41 B provided to the other of the attachment  5  and the handle ring  4 . 
     Further, in the present embodiment, each of the paired lengthwise sides  601 A,  601 B and  602 A,  602 B in the axial direction of the cam groove  6 A,  6 B is formed into a stepwise shape. However, it is sufficient that either one of the paired lengthwise sides  601 A,  601 B and  602 A,  602 B in the axial direction of the cam groove  6 A,  6 B is formed into a stepwise shape. In this situation, preferably, the lengthwise side (the first side  601 A,  601 B in the present embodiment) which comes in contact with the linking pin  41 A,  41 B when the attachment  5  is pressed against one&#39;s skin is formed into a stepwise shape. For example, when the slider part  51  is provided with the cam groove  6 A,  6 B, the lengthwise side  601 A,  602 A,  601 B,  602 B close to the attachment part  55  is formed into a stepwise shape, preferably. Meanwhile, when the handle ring  4  is provided with the cam groove  6 A,  6 B, the lengthwise side  601 A,  602 A,  601 B,  602 B which is an opposite side of the cam groove  6 A,  6 B from the attachment part  55  is formed into a stepwise shape, preferably. 
     Moreover, the step part  611 A,  612 A,  611 B,  612 B in the cam groove  6 A,  6 B is not necessarily shaped into a flat surface but may be shaped into a curved surface. 
     In the illustrated instance, to smoothly change the clipping height by means of moving forward or rearward the attachment  5 , the two cam grooves  6 A,  6 B are provided at an angular interval of 180 degree. Further in the illustrated instance, since the paired arm portions  52  and  52  are close to one side, the arm portions  52  are not in mutually symmetrical positions. Hence, to prevent improper assembly, the two cam grooves  6 A and  6 B have mutually different widths (the linking pins  41 A and  41 B have mutually different thickness). 
     To enable detachment of the attachment part  55 , the attachment  5  is separated into the attachment part  55  and the slider part  51 . The arm portion  52  of the slider part  51  for connection can be elastically bent inward within the inside of the through hole  35  of the cover block  31 . The detachment of the attachment part  55  from the slider part  51  can be performed irrespective of the level of the clipping height. 
     In brief, the attachment part  55  can be attached and detached without changing the clipping height from the desired level. The present embodiment has the greatly improved usability in contrast to a configuration where the attachment part  55  cannot be attached and detached unless the clipping height is set to the highest level. 
     Although the detachment is easy, the connection between the attachment part  55  and the slider part  51  is made inside the through hole  35  of the cover block  31 . Therefore, the unexpected detachment can be prevented. Even when the attachment part  55  is pressed against one&#39;s skin, the arm portion  52  supports the attachment part  55  at its apical end, and therefore the attachment part  55  can be prevented from being moved backward. Further, even when the attachment part  55  is detached, the arm portion  52  of the slider part  51  is covered with the cover block  31  and is not exposed outside. Thus, there is no possibility that the arm portion  52  catches in hairs. 
     As mentioned in the above, the hair clipper of the present embodiment includes: the fixed blade having the comb-like blade part; the movable blade having the comb-like blade part and moved in a reciprocation manner; the main body  1  incorporating the driving means (the motor  10 ) for reciprocating the movable blade; the attachment  5  disposed overlapping with the apical blade parts of the fixed blade and the movable blade and used for adjustment of the clipping height; and the handle ring  4  disposed to the main body  1  in such a manner to be allowed to rotate around a direction substantially normal to the sliding direction. One of the attachment  5  and the handle ring  4  is provided with the spiral cam groove  6 A,  6 B, and the other is provided with the linking pin  41 A,  41 B. The attachment  5  is allowed to slide in a blade edge direction normal to the reciprocation direction of the movable blade. The linking pin  41 A,  41 B is allowed to slide inside the cam groove  6 A,  6 B. The linking pin  41 A,  41 B is moved inside the cam groove  6 A,  6 B with the rotation of the handle ring  4 . Such movement of the linking pin  41 A,  41 B causes the attachment  5  to slide. As a result, the clipping height is adjusted. The cam groove  6 A,  6 B has the pair of the opposite lengthwise sides  601 A,  602 A,  601 B,  602 B, and one of the lengthwise sides  601 A,  602 A,  601 B,  602 B is formed into a stepwise shape so as to include the plural step parts  611 A,  612 A,  611 B,  612 B substantially normal to the sliding direction and the slope part  621 A,  622 A,  621 B,  622 B crossing the sliding direction obliquely and connecting between the step parts  611 A,  612 A,  611 B,  612 B. The linking pin  41 A,  41 B is positioned at the step part  611 A,  612 A,  611 B,  6128  of one lengthwise side  601 A,  602 A,  601 B,  602 B and holds the selected clipping height. 
     In other words, the hair clipper of the present embodiment includes the following first feature. In the first feature, the hair clipper includes the blade block  32 , and the adjusting device  7  for adjusting the clipping height of the blade block  32 . The adjusting device  7  includes the attachment  5 , the handle ring  4 , and the connection mechanism. The attachment  5  is disposed to overlap with the blade block  32  and to be allowed to move in the predetermined moving direction relative to the blade block  32 . The handle ring  4  is formed into the circular hollow cylindrical shape and is disposed to be rotated around the rotation axis extending along the moving direction. The connection mechanism connects the handle ring  4  to the attachment  5  such that the attachment  5  is moved with rotation of the handle ring  4 . The clipping height is determined by the relative position of the attachment  5  to the blade block  32  in the moving direction. The connection mechanism includes the cam groove  6 A,  6 B provided to one of the attachment  5  and the handle ring  4 , and the linking pin  41 A,  41 B provided to the other of the attachment  5  and the handle ring  4 , and placed inside the cam groove  6 A,  6 B so as to be moved along the cam groove  6 A,  6 B. The cam groove  6 A,  6 B includes the first side  601 A,  601 B and the second side  602 A,  602 B opposite to each other in the moving direction. The first side  601 A,  601 B includes plural step parts  611 A,  611 B formed in different positions in the moving direction respectively associated with the different clipping heights, and the slope part  621 A,  621 B configured to connect the step parts  611 A,  611 B. The step parts  611 A,  611 B extend in a direction normal to the moving direction. 
     Further, in the hair clipper of the present embodiment, the lengthwise side  601 A,  601 B,  602 A,  602 B which comes in contact with the linking pin  41 A,  41 B when the attachment  5  receives a force rolling back the attachment  5 , is adopted as the lengthwise side  601 A,  601 B,  602 A,  602 B including the step parts  611 A,  612 A,  611 B,  612 B and the slope parts  621 A,  622 A,  621 B,  622 B. 
     In other words, the hair clipper of the present embodiment includes the following second feature in addition to the first feature. In the second feature, the blade block  32  is provided with the blade section  320  at its end in the apical direction extending along the moving direction. The step part  611 A,  611 B is defined as a surface directed to the apical direction. Note that, the second feature is optional. 
     Moreover, the hair clipper of the present embodiment includes the following third feature in addition to the second feature. In the third feature, the attachment  5  includes the comb part  56  protruding along the apical direction. The clipping height is determined by the distance between the apical end of the blade section  320  and the apical end of the comb part  56  in the moving direction. Note that, the third feature is optional. 
     Additionally, in the hair clipper of the present embodiment, the pair of the opposite lengthwise sides  601 A,  602 A and  601 B,  602 B of the cam groove  6 A,  6 B is formed into a stepwise shape so as to include the plural step parts  611 A,  612 A,  611 B,  612 B substantially normal to the sliding direction and the slope part  621 A,  622 A,  621 B,  622 B crossing the sliding direction obliquely and connecting between the step parts  611 A,  612 A,  611 B,  612 B. The linking pin  41 A,  41 B is positioned between the step part  611 A,  612 A,  611 B,  612 B of one lengthwise side  601 A,  601 B,  602 A,  602 B and the step part  611 A,  612 A,  611 B,  612 B of the other lengthwise side  601 A,  601 B,  602 A,  602 B and holds the selected clipping height. 
     In other words, the hair clipper of the present embodiment includes the following fourth feature in addition to any one of the first to third features. In the fourth feature, the second side  602 A,  602 B includes the plural second step parts  612 A,  612 B respectively opposite to the plural step parts  611 A,  611 B, and the second slope part  622 A,  622 B configured to connect the second step parts  612 A,  612 B. The cam groove  6 A,  6 B is designed to hold the linking pin  41 A,  41 B between the step part  611 A,  611 B and the second step part  612 A,  612 B opposite thereto. Note that, the fourth feature is optional. 
     Further, the hair clipper of the present embodiment includes the following fifth feature in addition to the fourth feature. In the fifth feature, the second step parts  612 A,  612 B are parallel to the respective opposite step parts  611 A,  611 B. Note that, the fifth feature is optional. 
     Furthermore, the hair clipper of the present embodiment includes the following sixth feature in addition to the fifth feature. In the sixth feature, the distance between the step part  611 A,  611 B and the second step part  612 A,  612 B opposite to this step part  611 A,  611 B is equal to the dimension of the linking pin  41 A,  41 B in the moving direction. Note that, the sixth feature is optional. 
     Additionally, in the hair clipper of the present embodiment, the plurality of the linking pins  41 A,  41 B is provided. The linking pins  41 A,  41 B slide at respective different positions in the cam groove  6 A,  6 B. 
     In other words, the hair clipper of the present embodiment includes the following seventh feature in addition to any one of the first to sixth features. In the seventh feature, the connection mechanism includes a plurality of the linking pins  41 A,  41 B. Note that, the seventh feature is optional. 
     Further, the hair clipper of the present embodiment includes the following eighth feature in addition to the seventh feature. In the eighth feature, the plurality of the linking pins  41 A,  41 B are arranged so as to be respectively positioned at the mutual different step parts  611 A,  611 B when one of the linking pins  41 A,  41 B is positioned at one of the step parts  611 A,  611 B. Note that, the eighth feature is optional. Hence, a plurality of the linking pins  41 A,  41 B may be arranged so as to be positioned at the same step part  611 A,  611 B. 
     Additionally, in the hair clipper of the present embodiment, the plural spiral cam grooves  6 A and  6 B are parallel to each other. The plural linking pins  41 A,  41 B slide inside the respective corresponding cam grooves  6 A and  6 B. Further, the cam grooves  6 A and  6 B have mutually different widths and the linking pins  41 A and  41 B have mutually different thicknesses. 
     In other words, the hair clipper of the present embodiment includes the following ninth feature in addition to the seventh or eighth feature. In the ninth feature, the connection mechanism includes a plurality of the cam grooves  6 A and  6 B respectively corresponding to a plurality of the linking pins  41 A and  41 B. Note that, the ninth feature is optional. 
     Moreover, the hair clipper of the present embodiment includes the following tenth feature in addition to the ninth feature. In the tenth feature, the cam grooves  6 A and  6 B have mutually different widths. The linking pins  41 A and  41 B are designed to be fitted into the respectively corresponding cam grooves  6 A and  6 B. Note that, the tenth feature is optional. 
     Additionally, in the hair clipper of the present embodiment, the attachment  5  is constituted by the slider part  51  provided with either the cam groove  6 A,  6 B or the linking pin  41 A,  41 B and the attachment part  55  overlapped with the apical blade section  320  of the fixed blade and the movable blade. The attachment part  55  is detachably connected to the slider part  51  irrespective of the sliding position of the slider part  51 . 
     In other words, the hair clipper of the present embodiment includes the following eleventh feature in addition to any one of the first to tenth features. In the eleventh feature, the attachment  5  includes the attachment part  55  serving as a part overlapping with the blade block  32 , and the slider part  51  serving as a part attached to the handle ring  4 . The attachment part  55  is detachably attached to the slider part  51 . Note that, the eleventh feature is optional. 
     Further, the hair clipper of the present embodiment includes the following twelfth feature in addition to any one of the first to eleventh features. In the twelfth feature, the blade block  32  includes the two comb-like blades  321  and  322  arranged to overlap with each other. Note that, the twelfth feature is optional. 
     Furthermore, the hair clipper of the present embodiment includes the following thirteenth feature in addition to the twelfth feature. In the thirteenth feature, the hair clipper further includes the main body  1  configured to hold the blade block  32 . The attachment  5  and the handle ring  4  are attached to the main body  1 . Note that, the thirteenth feature is optional. 
     Moreover, the hair clipper of the present embodiment includes the following fourteenth feature in addition to the thirteenth feature. In the fourteenth feature, the hair clipper further includes the driving device (motor)  10  housed in the main body  1 . The driving device  10  is configured to reciprocate one of the two comb-like blades  321  and  322  relative to the other of the two comb-like blades  321  and  322  in the predetermined reciprocation direction. The moving direction is defined as a direction crossing the reciprocation direction. Note that, the fourteenth feature is optional. 
     According to the hair clipper of the present embodiment, with rotating the handle ring  4 , it is possible to easily vary the clipping height. Additionally, since each of the paired opposite lengthwise sides  601 A and  602 A,  601 B and  602 B of the cam groove  6 A,  6 B provided to one of the handle ring  4  and the attachment  5  is formed into a stepwise shape, movable range of the linking pin  41 A,  41 B is narrow at a position corresponding to the selected level of the clipping height. Consequently, the clipping height can be kept at the selected level precisely.