Abstract:
In a vehicle seat sliding apparatus of the type wherein rotating an operating lever causes a lock lever to allow an upper rail to slide along a lower rail, the operating member is supported by a supporting bracket fixed to the upper rail to rotate about a fulcrum which is in the form of a plate of the bracket. The operating lever is provided with a slit into which a spring is fitted for being urged. The bracket also holds the spring. To avoid an engagement between the plate and the slit when the operating lever passes during an assembly of the apparatus, the plate is configured to incline relative to the slit.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims priority under 35 U.S.C. Section 119 to Japanese Patent Application No. 2009-080240 filed on Mar. 27, 2009, the entire content of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a vehicle seat sliding apparatus. 
         [0004]    2. Description of the Related Art 
         [0005]    In the related art, various types of vehicle seat sliding apparatuses are proposed (for example, Japanese Patent No. 3646356, Japanese Patent No. 3449227, Japanese Patent No. 3647502, JP-A-59-2938). These apparatuses each include a lower rail and an upper rail connected to the lower rail so as to be movable with respect to the lower rail. Then, a lock lever adapted to engage the lower rail and selectively restrict the movement of the upper rail with respect to the lower rail is rotatably connected to the upper rail. The upper rail is also provided with an operating lever which is capable of transmitting an operating force to release the movement restriction with respect to the lock lever, and a torsion spring adapted to resiliently hold the operating lever. 
         [0006]    Incidentally, the vehicle seat sliding apparatuses in Japanese Patent No. 3646356, Japanese Patent No. 3449227, and Japanese Patent No. 3647502 are all configured to assemble the torsion spring to a lever (lock lever or the like) movable (rotatable) with respect to the upper rail, and hence the assembly work of the torsion spring becomes complicated. Then, a rod-shaped or a pipe-shaped operating lever has a configuration to be connected to the lever including the torsion spring assembled thereto in a state of being engaged with the torsion spring, and hence the assembly work of the operating lever also becomes complicated. In particular, in Japanese Patent No. 3646356 and Japanese Patent No. 3647502, the operating lever is connected so as to rotate integrally with the lock lever and, when the direction of rotation of the operating lever and the direction of rotation of the lock lever differ from each other, for example, an axis of rotation cannot be used commonly, so that the number of components and the number of steps of assembly are increased. 
       SUMMARY OF THE INVENTION 
       [0007]    Thus, a need exists for a seat sliding apparatus which is not susceptible to the drawback mentioned above. 
         [0008]    In order to solve the above-described problem, a first aspect of the invention provides a vehicle seat sliding apparatus including: a lower rail adapted to be fixed to a vehicle-floor, an upper rail adapted to be fixed to a seat cushion and connected to the lower rail so as to be movable with respect to the lower rail, a lock lever rotatably connected to the upper rail and adapted to engage the lower rail to selectively restrict the movement of the upper rail with respect to the lower rail; a supporting bracket fixed to the upper rail; an operating lever rotatably connected to the supporting bracket and being capable of transmitting an operating force to the lock lever to release the restriction of movement by being linked with the lock lever; and an urging member adapted to resiliently hold the operating lever, the supporting bracket including a plate-shaped supporting wall portion which is adapted to serve as a fulcrum of rotation of the operating lever at an abutting portion with respect to an upper portion of the operating lever when the operating lever is inserted therein along the longitudinal direction of the upper rail, the operating lever being formed with a slit-like holding groove adapted to lock the urging member therein on the upper portion thereof on the side of the lock lever with respect to the supporting wall portion in terms of the longitudinal direction of the upper rail so as to extend in the direction orthogonal to the direction of insertion of the operating lever, and the supporting wall portion having a molded portion opposing the upper portion of the operating lever within the range of the holding groove in the direction orthogonal to the direction of insertion of the operating lever and having a width wider than the width of the holding groove in terms of the direction of insertion of the operating lever. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view showing an embodiment according to the invention; 
           [0010]      FIG. 2  is a cross-sectional view taken along the line A-A in  FIG. 1 ; 
           [0011]      FIG. 3  is a side view showing the same embodiment; 
           [0012]      FIG. 4A  is a plan view showing the same embodiment; 
           [0013]      FIG. 4B  is a side view showing the same embodiment; 
           [0014]      FIG. 5A  is a plan view showing a state of assembly in the same embodiment; 
           [0015]      FIG. 5B  is a plan view showing the state of assembly in the same embodiment; 
           [0016]      FIG. 6  is a plan view showing a modification of the invention; 
           [0017]      FIG. 7A  is a plan view showing a related mode of the invention; 
           [0018]      FIG. 7B  is a plan view showing the related mode of the invention; 
           [0019]      FIG. 8  is a plan view showing the modification of the invention; 
           [0020]      FIG. 9  is a plan view showing the modification of the invention; 
           [0021]      FIG. 10  is a cross-sectional view showing the modification of the invention; 
           [0022]      FIG. 11  is a cross-sectional view showing the modification of the invention; and 
           [0023]      FIG. 12  is a schematic diagram showing the embodiment of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    Referring now to the drawings, an embodiment in which the invention is embodied will be described below. 
         [0025]      FIG. 1  is a perspective view showing a vehicle seat sliding apparatus  1  according to the embodiment which is mounted on a vehicle such as an automotive vehicle, and  FIG. 2  is a lateral cross-sectional view taken along the line A-A in  FIG. 1 . As shown in  FIG. 1 ,  FIG. 2 , and  FIG. 12 , a lower rail  3  is fixed to a vehicle-floor  2  in a state of extending in the fore-and-aft direction of the vehicle, and an upper rail  4  is mounted to the lower rail  3  so as to be movable relatively to the lower rail  3 . A seat cushion  80  is fixed to the upper rail  4 . 
         [0026]    As shown in  FIG. 2 , the lower rail  3  includes a pair of side wall portions  11  extending upright from both sides thereof in terms of the widthwise direction and a bottom wall portion  12  connecting proximal ends (lower ends) of the side wall portions  11 . Then, folded-back wall portions  13  which are formed to protrude inward in terms of the widthwise direction and then folded backward toward the proximal end sides of the side wall portions  11  are formed continuously from distal ends (upper ends) of the respective side wall portions  11 . 
         [0027]    In contrast, the upper rail  4  includes a pair of side wall portions  14  extending in the vertical direction between the both folded-back wall portions  13  of the lower rail  3  and a lid wall portion  15  connecting proximal ends (upper ends) of the side wall portions  14 . Then, folded-back wall portions  16  which are formed to protrude outward in terms of the widthwise direction and then folded so as to be surrounded by the side wall portions  11  and the folded-back wall portions  13  are formed continuously from distal ends (lower ends) of the respective side wail portions  14 . 
         [0028]    In other words, the lower rail  3  and the upper rail  4  each include a U-shaped rail cross section with opening sides butted against to each other, and are held so as not to be disconnected from each other in the vertical direction mainly by the engagement of the folded-back wall portions  13  and  16 . The rail cross section formed by the lower rail  3  and the upper rail  4  assumes so-called a box shape in a rectangular shape. The lower rail  3  defines an internal space S in cooperation with the upper rail  4 . 
         [0029]    Retainers  18  adapted to hold pairs of rolling elements  17  arranged in the vertical direction are mounted between the respective folded-back wall portions  18  and the side wall portion  11  opposing thereto, and the upper rail  4  is supported so as to be slidable in the longitudinal direction (the fore-and-aft direction of the vehicle) with respect to the lower rail  3  in a state of rolling the rolling elements  17  with respect to the lower rail  3 . 
         [0030]    Here, the folded-back wall portion  13  on one side of the lower rail  3  in terms of the widthwise direction (right side in  FIG. 2 ) is formed with a plurality of lock holes  13   a  arranged crosswise at predetermined intervals over the substantially entire length of the longitudinal direction (the direction orthogonal to the paper plane) thereof. In contrast, a through hole  4   a  formed by removing a corner formed by the lid wall portion  15  and the side wall portion  14  on one side in terms of the widthwise direction (right side in  FIG. 2 ) is formed at a center portion of the upper rail  4  in terms of the longitudinal direction, and the side wall portion  14  concerned is formed with a plurality of insertion holes  14   a  arranged crosswise on the lower portion thereof at the predetermined distances within a range of the through hole  4   a  in terms of the longitudinal direction and, in addition, the folded-back wall portion  16  which continued from the side wall portion  14  concerned is formed with the same number of insertion holes  16   a  as the insertion holes  14   a  arranged crosswise at the predetermined intervals. The plurality of insertion holes  14   a ,  16   a  are arranged so as to oppose to each other in terms of the widthwise direction at positions which can align with the same number of lock holes  13   a  on the lower rail  3  adjacent to each other in terms of the longitudinal direction. 
         [0031]    A lock lever  21  formed of a plate member is rotatably connected to the upper rail  4  via a bracket  23  within a range of the through hole  4   a  in terms of the longitudinal direction. The lock lever  21  includes a flat panel-shaped body portion  21   a  and a pair of supporting strips  21   b  bent upward from both ends of a lower portion of the body portion  21   a  in terms of the longitudinal direction (the direction orthogonal to the paper plane) of the upper rail  4 . The lock lever  21  is supported by the both supporting strips  21   b  so as to be rotatable about an axis of rotation O 1  extending in the longitudinal direction of the upper rail  4  outside the internal space S. The lock lever  21  is formed with locking claws  21   c  formed from the body portion  21   a  so as to enter the interior of the internal space S through the through holes  4   a  and bent outward in terms of the widthwise direction by the same number as the insertion holes  14   a  or the like at the predetermined intervals. The respective locking claws  21   c  are arranged so as to be inserted into and pulled out from the insertion holes  14   a ,  16   a  in association with the rotation of the lock lever  21  about the axis of rotation O 1 . 
         [0032]    When the respective locking claws  21   c  are inserted into the lock holes  13   a  as well as into the insertion holes  14   a ,  16   a , the relative movement between the lower rail  3  and the upper rail  4  is restricted. Alternatively, when the respective locking claws  21   c  are pulled out from the insertion holes  16   a , the lock holes  13   a , and the insertion holes  14   a  in sequence, the relative movement between the lower rail  3  and the upper rail  4  is allowed. 
         [0033]    A torsion wire  22  (see  FIG. 1 ) formed of a single wire member is installed on an upper portion of the upper rail  4 . The torsion wire  22  is locked at one end and the other end with the lock lever  21  and the bracket  23 , respectively. The lock lever  21  is constantly urged in the direction of rotation on the side where the locking claws  21   c  are inserted into the insertion holes  14   a  and the like (the counterclockwise direction in  FIG. 2 ) by the torsion wire  22 . 
         [0034]    In addition, the lock lever  21  is bent from an upper portion of the body portion  21   a  toward a distal end thereof so as to be inclined obliquely downward, and forms an abutting portion  21   d  on an upper surface of the bent portion concerned. 
         [0035]    The vehicle seat sliding apparatus  1  includes the lower rails  3 , the upper rails  4 , and the lock levers  21  described above disposed in pair respectively in terms of the rail width direction, and a seat cushion which forms a seating portion of an occupant is fixed to and supported by the both upper rails  4 . Therefore, when the relative movement between the upper rails  4  with respect to the lower rails  3  is restricted by the engagement between the locking claws  21   c  of the lock levers  21  and the lock holes  13   a  of the lower rails  3 , the seat is held at a predetermined position with respect to the vehicle-floor  2 . Also, when the restriction of the relative movement is released by the release of the engagement between the locking claws  21   c  of the lock levers  21  and the lock holes  13   a  of the lower rails  3 , adjustment in position of the seat with respect to the vehicle-floor  2  in the longitudinal direction of the upper rails  4  (the fore-and-aft direction of the vehicle) is allowed. 
         [0036]    As shown in  FIG. 1 , a supporting bracket  31  formed of a plate member is fixed to the each upper rail  4  on one side (lower left side in  FIG. 1 ) of the lock lever  21  in terms of the longitudinal direction. The supporting bracket  31  includes a mounting wall portion  32  extending in the widthwise direction of the upper rail  4  and being tightened to the lid wall portion  15 , and also includes a first side wall portion  33  extending downward from a distal end of the mounting wall portion  32  outside the lower rail  3  in terms of the widthwise direction. The supporting bracket  31  includes a bottom wall portion  34  extending from a lower end of the first side wall portion  33  outward in terms of the widthwise direction of the lower rail  3 , includes a triangle second side wall portion  35  extending upward from a distal end of the bottom wall portion  34 , and further includes a supporting wall portion  36  extending from the end on one side (lower left side in  FIG. 1 ) of the first side wall portion  33  outward In terms of the widthwise direction of the lower rail  3 . 
         [0037]    The first and second side wall portions  33  and  35  are arranged in parallel to each other and apart from each other in the rail width direction (see  FIG. 4A ). Then, the second side wall portion  35  includes a projecting strip  35   a  at a distal end portion thereof on the side of the supporting wall portion  36 , and includes a pair of groove portions  35   b ,  35   c  on the proximal side of the projecting strip  35   a  (see  FIG. 4B ). The directions of depression of the both groove portions  35   b ,  35   c  are substantially orthogonal to each other. The bottom wall portion  34  connects lower ends of the first and second side wall portions  33  and  35  on one side (right side in  FIG. 4A ) in terms of the longitudinal direction of the upper rail  4 , and a range defined by the bottom wall portion  34  and the supporting wall portion  36  in plan view is an opening OP. In addition, the supporting wall portion  36  includes an inclined wall portion  36   a  as a molded portion which is displaced, away from the first side wall portion  33  in the longitudinal direction of the upper rail  4  as it goes outward in terms of the widthwise direction of the upper rail  4  from one side end of the first side wall portion  33 , and a linear wall portion  36   b  extending from a distal end of the inclined wall portion  36   a  in the rail width direction. Then, the supporting wall portion  36  is formed with a square insertion hole  37  opening in the longitudinal direction of the upper rail  4 . The insertion hole  37  is formed so as to extend across the range of the inclined wall, portion  36   a  and the linear wall portion  36   b.    
         [0038]    As shown in  FIGS. 4A and 4B , the supporting bracket  31  is attached with a torsion spring  41  formed of a single wire member as an urging member. The torsion spring  41  includes a first terminal portion  42  extending in the rail width direction at a position of the opening OP and inserted into and locked by the first side wall portion  33 , and also includes a first extending portion  43   b  being arranged between the first and second side wall portions  33  and  35  above the bottom wall portion  34  and extending from the proximal end of the first terminal portion  42  toward the lock lever  21  in the longitudinal direction of the upper rail  4 , a locked strip portion  43   a  extending linearly toward the second side wall portion  35  in the rail width direction in a state of being bent from a distal end of the first extending portion  43   b , and a second extending portion  43   c  extending toward the opposite side from the lock lever  21  in the longitudinal direction of the upper rail  4  in a state of being bent from a distal end of the locked strip portion  43   a . The first extending portion  43   b , the locked strip portion  43   a , and the second extending portion  43   c  form a so-called hairpin-shaped extending portion  43 . The torsion spring  41  also includes a shaft portion  44  which is bent from a distal end of the second extending portion  43   c  (extending portion  43 ) at the position of the opening OP outward in the rail width direction and is inserted into and locked by the second side wall portion  35  so as to assume a state of fitted into one of the groove portions  35   b  of the second side wall portion  35 . The shaft portion  44  extends coaxially with the first terminal portion  42 , and serves as an axis of rotation of the extending portion  43  (first extending portion  43   b , locked strip portion  43   a , and second extending portion  43   c ) in cooperation with the first terminal portion  42 . In addition, the torsion spring  41  includes a locked portion  45  which is bent from a distal end of the shaft portion  44 , and is inserted into and locked by the second side wall portion  35  so as to assume a state of fitted into the other groove portion  35   c  of the second side wall portion  35 . The locked portion  45  twists the shaft portion  44  to cause the locked strip portion  43   a  to generate a downward urging force. Also, the torsion spring  41  includes a second terminal portion  46  extending from a distal end of the locked portion  45  at the position of the opening OP. 
         [0039]    In an assembly step of the torsion spring  41 , first of all, the first terminal portion  42  is inserted into the first side wall portion  33  in a state in which the extending portion  43  is arranged on the bottom wall portion  34 , which is positioned between the first and second side wall portions  33  and  35 . Then, when the projecting strip  35   a  is inserted between the shaft portion  44  and the locked portion  45  in this state, the shaft portion  44  and the locked portion  45  are fitted into the pair of groove portions  35   b ,  35   c  respectively while being broadened by the projecting strip  35   a , so that the projecting strip  35   a  is resiliently clamped. Accordingly, the assembly work of the torsion spring  41  to the supporting bracket  31  is completed. 
         [0040]    As shown in  FIG. 1 , an operating lever  51  formed by bending a tubular member is connected to the supporting bracket  31  on each side in the rail width direction. In other words, the operating lever  51  is formed into a U-shape having an operating portion  51   a  extending in the rail width direction, and a pair of distal end portions  51   b  bent respectively from both ends of the operating portion  51   a  toward the lock levers  21  in the longitudinal direction of the upper rail  4 . Then, the operating lever  51  includes flat-shaped pressing portions  52  formed by collapsing the respective distal end portions  51   b  in the vertical direction and slit-like holding grooves  53  formed on the proximal side of the each flat-shaped pressing portion  52  so as to extend in the rail width direction by removing part of an upper portion thereof. The each holding groove  53  extends in the direction orthogonal to the direction of insertion of the operating lever  51 . 
         [0041]    The operating lever  51  is supported by the supporting wall portion  36  (supporting bracket  31 ) by the each distal end portion  51   b  thereof being inserted into the insertion hole  37  of the supporting wall portion  36  along the longitudinal direction of the upper rail and is linked with the lock lever  21  by the respective pressing portions  52  being placed on the abutting portions  21   d  of the lock lever  21  (see  FIG. 2 ). At this time, as shown in  FIG. 3 , the extending portion  43  of the each torsion spring  41  is pressed against the distal end portion  51   b  (pressing portion  52 ) of the operating lever  51  passing under the extending portion  43  along the bottom wall portion  34  between the first and second side wall portions  33  and  35 , and hence is rotated upward (counterclockwise in the drawing) about the first terminal portion  42  and the shaft portion  44  against the urging force. Then, in association with the insertion of the each distal end portion  51   b  of the operating lever  51 , when the holding groove  53  reaches the linear locked strip portion  43   a  which slides on the upper portion thereof, the locked strip portion  43   a  is fitted into the holding groove  53 . Accordingly, the each distal end portion  51   b  of the operating lever  51  is locked and prevented from being disconnected in a state in which the upper portion is urged downward in the holding groove  53  by the torsion spring  41  (locked strip portion  43   a ). Needless to say, the locked portion  45  generates an urging force which urges the upper portion (holding groove  53 ) of the operating lever  51  downward. In contrast, the second terminal portion  46  of the torsion spring  41  urges the lower portion of the each distal end portion  51   b  of the operating lever  51  upward at the position of the opening OP. 
         [0042]    As shown in  FIGS. 5A and 5B , when the width of the holding groove  53  in the direction of insertion of the operating lever  51  is expressed as a width W 1 , the supporting wall portion  36  having the inclined wall portion  36   a  has a width W 2  substantially larger than the width W 1  within a range of the holding groove  53  in the direction orthogonal to the direction of insertion of the operating lever  51 . In other words, the supporting wall portion  36  opposes the upper portion of the operating lever  51  and has the width W 2  substantially larger than the width W 1 . Therefore, when the holding groove  53  passes the supporting wall portion  36  during the insertion and assembly works of the operating lever  51 , the supporting wall portion  36  is not fitted to the holding groove  53  by being blocked by the inclined wall portion  36   a.    
         [0043]    In other words, as shown in  FIGS. 7A and 7B , it is assumed that the supporting bracket  31  includes a flat-plate shaped supporting wall portion  91  extending from a distal end of the first side wall portion  33  toward the second side wall portion  35  in the widthwise direction, and the supporting wall portion  91  is formed with an insertion hole  92  which penetrates through the longitudinal direction of the upper rail  4 . In this case, when assembling the operating lever  51  to the supporting bracket  31 , the holding groove  53  of the operating lever  51  passes the supporting wall portion  91 , the supporting wall portion  91  may interfere with the holding groove  53  so as to fit therein as shown in  FIG. 7B , so that the assembleability of the operating lever  51  might be impaired. In contrast, in order to avoid the deterioration of the assembleability as described above, it is conceivable to increase the thickness of the supporting wall portion  91  (supporting bracket  31 ) to an extent which cannot be fitted into the holding groove  53 . However, in this case, increase in weight or degradation of workability of the supporting bracket  31  is inevitable. In contrast, it is conceivable to reduce the width of the holding groove  53  to an extent that the supporting wall portion  91  cannot be fitted. However, in this case, a retention force to retain the torsion spring  41  (locked strip portion  43   a ) in the holding groove  53  is reduced. Alternatively, when the torsion spring  41  is thinned (reduced in diameter) in association with the reduction of the width of the holding groove  53 , the urging force of the torsion spring  41  is insufficient. 
         [0044]    However, in this embodiment, since the supporting wall portion  36  does not fit into the holding groove  53  in the configuration as described above, the assembleability of the operating lever  51  is improved. 
         [0045]    Then, the each supporting wall portion  36  (insertion hole  37 ) serves as a fulcrum of the rotation of the operating lever  51  at the abutting portion of the operating lever  51  with respect to an upper portion of the distal end portion  51   b . Therefore, the each supporting wall portion  36  supports the operating lever  51  so as to be rotatable about an axis of rotation O 2  set at an abutment portion thereof with respect to the operating lever  51  (an upper portion of the distal end portion  51   b ). The reason why the fulcrum of the rotation of the operating lever  51  is set using the supporting bracket  31  (supporting wall portions  36 ) is for balancing an operating force and an operating amount of the operating lever  51  required for releasing the lock lever  21  using the principle of a lever. It is needless to say that the direction of rotation of the operating lever  51  is different from the direction of rotation of the lock lever  21 . The torsion spring  41  is adapted to retain the operating lever  51  resiliently for maintaining the linked state of the operating lever  51  with respect to the lock lever  21 . Alternatively, the torsion spring  41  may be adapted to hold the operating lever  51  resiliently so that the operating lever  51  releases the operating force for releasing the restriction of movement of the lower rail  3  and the upper rail  4  with respect to the lock lever  21  is also applicable. 
         [0046]    In this configuration, it is assumed that the operating lever  51  is operated to lift the operating portions  51   a , and the both distal end portions  51   b  of the operating lever  51  are rotated clockwise about the axis of rotation O 2  in  FIG. 3 . At this time, the each pressing portion  52  of the operating lever  51  is moved downward in  FIG. 2 , and hence presses the abutting portion  21   d  of the lock lever  21  downward. Accordingly, the each lock lever  21  is rotated clockwise about the axis of rotation O 1 , that is, in the direction of rotation in which the locking claw  21   c  is moved away from the insertion hole  14   a  or the like against the urging force of the torsion wire  22 . Accordingly, the restriction of the relative movement between the lower rail  3  and the upper rail  4  is released. 
         [0047]    In contrast, when the operating force of the operating lever  51  (the operating portion  51   a ) is released, the lock lever  21  is urged by the torsion wire  22 , and is rotated (backward) counterclockwise about the axis of rotation O 1  in  FIG. 2 , that is, in the direction of rotation on the side in which the locking claw  21   c  is inserted into the insertion hole  14   a  or the like. Accordingly, the relative movement between the lower rail  3  and the upper rail  4  is restricted again. Also, the both distal end portions  51   b  of the operating lever  51  are rotated counterclockwise about the axis of rotation O 2  in  FIG. 3  in association with the movement of the lock levers  21 . 
         [0048]    As described above in detail, the following advantages are achieved according to this embodiment. 
         [0049]    (1) In this embodiment, the operating lever  51  can be assembled easily to the supporting bracket  31  by inserting the same through the supporting wall portion  36  along the longitudinal direction of the upper rail  4  and causing the torsion spring  41  to be locked in the holding groove  53 . Accordingly, the axis of rotation O 2  of the operating lever  51  can be set separately from the axis of rotation O 2  of the lock lever  21  only by inserting the operating lever  51  into the supporting wall portion  36 . In this case, the direction of rotation of the operating lever  51  does not have to match with the direction of rotation of the lock lever  21 . Also, when the holding groove  53  passes the supporting wall portion  36  during the insertion and assembly works of the operating lever  51 , the inclined wall portion  36   a  prevents the supporting wall portion  36  (the fulcrum portion of the operating lever  51 ) from being fitted into the holding groove  53 . Accordingly, the assembly work of the operating lever  51  can be smoothly performed. Also, since the thickness of the supporting wall portion  36  by itself is not basically constrained by the width of the holding groove  53 , for example, weight increase in association with needless increase in thickness of the supporting wall portion  36  (supporting bracket  31 ) or degradation of workability of the supporting bracket  31  can be restrained. 
         [0050]    (2) In this embodiment, the inclined wall portion  36   a  of the supporting wall portion  36  can be provided in an extremely simple method by bending a supporting wall portion  61 , for example. 
         [0051]    (3) In this embodiment, since a transmitting member (lever or the like) for changing the direction does not have to be provided separately between the lock lever  21  and the operating lever  51  even though the direction of rotation of the lock lever  21  is different from the direction of rotation of the operating lever  51 , increase in number of components and the number of assembly steps can be restrained. 
         [0052]    The embodiment described above may be modified as follows. 
         [0053]    As shown in  FIG. 6 , the supporting bracket  31  may have the flat panel-shaped supporting wall portion  61  being bent from the distal end of the first side wall portion  33  on the opposite side from the lock lever  21  at a substantially right angle and extending toward the second side wall portion  35  in the widthwise direction. The supporting wall portion  61  is also formed with a square insertion hole  62  opening in the longitudinal direction of the upper rail  4 . In this case, a half blanking portion  63  as a molded portion projecting in the direction of insertion of the operating lever  51  is formed on the supporting wall portion  61 . The half blanking portion  63  is formed over a part of the range of the insertion hole  62 . 
         [0054]    The supporting wall portion  61  having the half blanking portion  63  has a width W 11  which is substantially larger than the width W 1  in a range of the holding groove  53  orthogonal to the direction of insertion of the operating lever  51 . In other words, the supporting wall portion  61  opposes the upper portion of the operating lever  51  and has the width W 11  substantially larger than the width W 1 . Therefore, when the holding groove  53  passes by the supporting wall portion  61  during the insertion and assembly works of the operating lever  51 , the supporting wall portion  61  is not fitted to the holding groove  53  by being blocked by the half blanking portion  63 . Such the half blanking portion  63  may be provided by press work (half blankingting) of the supporting wall portion  61 , for example. 
         [0055]    As shown in  FIG. 8 , a torsion spring  71  having a widely formed locked strip portion to be fitted into the holding groove  53  may be employed. In other words, the torsion spring  71  includes a first extending portion  72  being arranged between the first and second side wall portions  33  and  35  above the bottom wall portion  34  and extending from the proximal end of the first terminal portion  42  toward the lock lever  21  in the longitudinal direction of the upper rail  4 , a locked strip portion  73  extending linearly toward the second side wall portion  35  in the rail width direction in a state of being bent from a distal end of the first extending portion  72 , and a second extending portion  74  extending toward the opposite side of the lock lever  21  in the longitudinal direction of the upper rail  4  in a state of being bent from a distal end of the locked strip portion  73  and continued to the shaft portion  44 . Then, the second extending portion  74  includes a proximal end portion  74   a  extending from the shaft portion  44  in parallel to the first extending portion  72 , and a distal end portion  74   b  continued to the locked strip portion  73  by being displaced gradually from a distal end of the proximal end portion  74   a  in the widthwise direction of the upper rail  4 . Accordingly, in the widthwise direction of the upper rail  4 , for example, a length L 1  of the locked strip portion  73  is set to be longer than a distance L 2  between the first extending portion  72  and the second extending portion  74  of the shaft portion  44  (axis of rotation). Therefore, even though the operating lever  51  is displaced within the range between the first side wall portion  33  and the second side wail portion  35  in the widthwise direction of the upper rail  4 , for example, the torsion spring  71  (locked strip portion  73 ) can be prevented from coming off from the holding groove  53 . 
         [0056]    The second extending portion  74  is continued to the locked strip portion  73  which is relatively longer in the widthwise direction of the upper rail  4  at the distal end portion  74   b  thereof. Then, the first extending portion  72  and the second extending portion  74  assume a shape reduced in terms of the widthwise direction of the upper rail  4  at the proximal end portion  74   a  which extends in parallel to the corresponding first extending portion  72  in comparison with the locked strip portion  73 . Therefore, when inserting the operating lever  51  underside the locked strip portion  73  to cause the torsion spring  71  (locked strip portion  73 ) to be locked in the holding groove  53  arranged on the upper portion of the operating lever  51  during the assembly work of the operating lever  51 , the proximal end portion  74   a  (reduced shape) prevents the operating lever  51  from being erroneously inserted into a frame surrounded by the first extending portion  72 , the locked strip portion  73 , and the second extending portion  74 . 
         [0057]    Alternatively, as shown in  FIG. 9 , a torsion spring  76  having a second extending portion  77  which connects the locked strip portion  73  and the shaft portion  44  linearly may also be employed. In this case as well, even though the operating lever  51  is displaced within the range between the first side wall portion  33  and the second side wall portion  35  in the widthwise direction of the upper rail  4  with the mode as described above, the torsion spring  71  (locked strip portion  73 ) can be prevented from coming off from the holding groove  53 . In particular, since the second extending portion  77  extends linearly, the number of steps of bending the same can be reduced. 
         [0058]    As shown in  FIG. 10 , a pressing portion  82  as a terminal of the operating lever  51  may be formed by collapsing the each distal end portion  51   b  into a shape collapsed into a flat panel shape in the vertical direction. In this case, restricting portions  82   a  are formed on opposing sides of the both pressing portions  82  in terms of the widthwise direction (seat widthwise direction) thereof so as to be inclined substantially downward toward a distal end thereof. The both restricting portions  82   a  are formed symmetrically in terms of the widthwise direction, and are able to engage bent portions  21   e  which are inclined from the abutting portions  21   d  of the lock levers  21  obliquely downward toward distal ends thereof. The both restricting portions  82   a  are adapted to restrict the displacement of the operating lever  51  in the seat width direction. With such deformation, when the operating lever  51  is about to be displaced in either direction in the seat width direction, the restricting portion  82   a  of the corresponding distal end portion  51   b  engages the lock lever  21  (bent portion  21   e ) to restrict the displacement of the operating lever  51  in the seat width direction. Therefore, further stable release of, the restriction of the movement of the lock lever  21  by the operation of the operating lever  51  is achieved. 
         [0059]    In other words, for example, as in the case of the vehicle seat sliding apparatus disclosed in JP-A-2006-298104, for example, if the pressing portion (rear end operating portion) as the terminal of the operating lever has a flat shape only for being placed on the lock lever, since there is no means of restricting the positional displacement of the operating lever in the seat width direction, so that the release of the movement restriction of the lock lever may become unstable depending on the extent of the displacement. 
         [0060]    Also, since the pressing portion  82  of the operating lever  51  is provided with the restricting portion  82   a , the rigidity can be improved by the increase of the second moment of area. 
         [0061]    Alternatively, as shown in  FIG. 11 , a pressing portion  84  as the terminal of the operating lever  51  may be formed by collapsing the each distal end portion  51   b  into a shape collapsed into an arcuate shape in the vertical direction. In this case, restricting portions  84   a  are formed on opposing sides of the both pressing portions  82  in terms of the widthwise direction (seat widthwise direction) thereof so as to be extended smoothly substantially downward toward the distal end (lower end) thereof. With such a deformation, the displacement of the operating lever  51  in the seat width direction can be restricted with the mode as described above, and the further stable release of the movement restriction of the lock lever  21  by the operation of the operating lever  51  is achieved. 
         [0062]    Although the first side wall portion  33  and the second side wall portion  35  of the supporting bracket  31  are arranged on the side of the upper rail  4  and the opposite side thereof in the rail width direction respectively in the embodiment described above, the positional relation may be vice versa. In this case, the torsion springs  41 ,  71 , and  76  may be assembled basically in the reverse direction so as to match the relation of arrangement of the first and second side wall portions  33  and  35 . The supporting wall portion  36  may be continued to the second side wall portion  35 . 
         [0063]    In the embodiment described above, the urging device to be locked in the holding groove  53  may be, for example, a leaf spring. 
         [0064]    In the embodiment described above, the number of locking claws  21   c  to be provided on the lock lever  21  may be any number as long as there is at least one. 
         [0065]    In the embodiment described above, the cross-sectional shape of the lower rail  3  is shown simply as an example. For example, the folded-back wall portions  13  may be protruded outward in terms of the rail widthwise direction. 
         [0066]    In the embodiment described above, the cross-sectional shape of the upper rail  4  is shown simply as an example. For example, the folded-back wall portions  16  may be protruded inward in terms of the rail widthwise direction. The cross section of the upper rail  4  is not limited to the U-shape, but may be an inverted T-shape, for example. 
         [0067]    The direction of movement of the seat in association with the movement of the upper rail  4  with respect to the lower rail  3  may be, for example, the fore-and-aft direction or the widthwise direction of the vehicle. 
         [0068]    According to one embodiment of the invention, the operating lever can be assembled easily to the supporting bracket by inserting the same through the supporting wall portion along the longitudinal direction of the upper rail and causing the urging member to be locked in the holding groove. Accordingly, the axis of rotation of the operating lever can be set separately from the axis of rotation of the lock lever only by inserting the operating lever through the supporting wall portion. In this case, the direction of rotation of the operating lever does not have to match with the direction of rotation of the lock lever. Also the supporting wall portion includes the molded portion having a width wider than the width of the holding groove in terms of the direction of insertion of the operating lever so as to oppose the upper portion of the operating lever within the range of the holding groove in terms of the direction orthogonal to the direction of insertion of the operating lever. Therefore, when the holding groove passes the supporting wall portion during the insertion and assembly works of the operating lever, the molded portion prevents the supporting wall portion (the fulcrum portion of the operating lever) from being fitted into the holding groove. Accordingly, the assembly work of the operating lever can be smoothly performed. Also, since the thickness of the supporting wall portion by itself is not basically constrained by the width of the holding groove, for example, weight increase in association with needless increase in thickness of the supporting wall portion (supporting bracket) or degradation of workability of the supporting bracket can be restrained. 
         [0069]    According to one embodiment of the invention, the inclined wall portion as the molded portion can be provided in an extremely simple method by bending the supporting wall portion, for example. 
         [0070]    According to one embodiment of the invention, the half blanking portion as the molded portion can be provided by a press work (half blankingting) on the supporting wall portion, for example. 
         [0071]    According to one embodiment of the invention, since the length of the locked strip portion is set to be longer than the distance of the axis of rotation between the first extending portion and the second extending portion in the widthwise direction of the upper rail, so that the urging member (locked strip portion) can be prevented from coming off the holding groove even though the operating lever is displaced within the range between the first side wall portion and the second side wall portion in the widthwise direction concerned, for example. 
         [0072]    According to one embodiment of the invention, the first extending portion or the second extending portion is continued to the locked strip portion which is relatively longer in the widthwise direction of the upper rail at a distal end portion thereof. In other words, the first extending portion and the second extending portion assume a shape reduced in terms of the widthwise direction of the upper rail at the proximal end portion which extends in parallel to the corresponding first extending portion or the second extending portion in comparison with the locked strip portion. Therefore, when inserting the operating lever underside the locked strip portion to cause the urging member (locked strip portion) to be locked in the holding groove arranged on the upper portion of the operating lever during the assembly work of the operating lever, the proximal end portion (reduced shape) can prevent the operating lever from being erroneously inserted into a frame surrounded by the first extending portion, the locked strip portion, and the second extending portion. 
         [0073]    According to one embodiment of the invention, when the operating lever is about to be displaced in either direction in the seat width direction, the restricting portion of the corresponding lever portion engages the lock lever to restrict the displacement of the operating lever in the seat width direction. Therefore, further stable release of the restriction of the movement of the lock lever by the operation of the operating lever is achieved. 
         [0074]    According to one embodiment of the invention, a vehicle seat sliding apparatus in which the assembleability of the operating lever can be improved without restrictions in the direction of rotation of the operating lever resiliently held by the urging device is provided. 
         [0075]    The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.