Abstract:
A vehicle seat position adjusting device includes a slide adjuster having a slide lock mechanism for slidably supporting a vehicle seat relative to a vehicle floor and holding the vehicle seat at a predetermined position relative to the vehicle floor by restricting a relative sliding movement of the vehicle seat relative to the vehicle floor, a reclining adjuster for rotatably supporting a seat back of the vehicle seat about a rotational axis line relative to a seat cushion of the vehicle seat, and a walk in mechanism disposed between the slide adjuster and the reclining adjuster for actuating the slide lock mechanism of the slide adjuster to allow the sliding movement of the vehicle seat relative to the vehicle floor when the seat back is rotated equal to or more than a predetermined angle relative to the seat cushion by operating the reclining adjuster. The walk in mechanism includes a detecting plate for detecting the predetermined angle or more than the predetermined angle rotation of the seat back relative to the seat cushion to the predetermined and the reclining adjuster includes a supporting surface arranged at an outer profile of the reclining adjuster in parallel to an extension direction of the rotational axis line of the seat back relative to the seat cushion.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application 2004-100347, filed on Mar. 30, 2004, the entire content of which is incorporated herein by reference.  
       FIELD OF THE INVENTION  
       [0002]     This invention relates to a vehicle seat position adjusting device, and more particularly, the invention relates to a vehicle seat position adjusting device which includes a walk in mechanism that allows the frontward sliding movement of the vehicle seat relative to a vehicle floor when a seat back is forwardly rotated to a predetermined angle relative to the seat cushion.  
       BACKGROUND  
       [0003]     Conventionally, the seat position adjusting device is known, for example, by a Japanese Patent Publication 10-44838 A. In this publication, the seat position adjusting device includes a slide adjuster having a slide lock mechanism for slidably supporting the vehicle seat relative to the vehicle floor and holding the seat to a predetermined position relative to the vehicle floor by restricting the slidable movement of the seat relative to the floor, a reclining adjuster provided between the slide adjuster and the reclining adjuster for rotatably supporting the seat back of the seat relative to the seat cushion of the seat around the rotational axis line and a walk in mechanism for allowing the sliding movement of the seat relative to the vehicle floor by actuating the slide lock mechanism of the slide adjuster when the seat back is rotated to a predetermined angle relative to the seat cushion.  
         [0004]     The walk in mechanism of this publication includes a detecting plate for detecting the rotation angle of the seat back relative to the seat cushion. This detecting plate is supported at a tip end of the rotation shaft, which forms a rotation axis line for seat cushion. The detecting plate engages with the seat back and rotates together with the seat back around the rotation shaft when the seat back is rotated to a predetermined angle relative to the seat cushion. Thus the detecting plate detects the rotation of the seat back relative to the seat cushion.  
         [0005]     According to this related art, the detecting plate is arranged protruding sideward from the reclining adjuster. This is because the detecting plate is provided at the tip end of the rotation shaft. This will require the space in sideward in seat width direction. In a very limited space in the occupant compartment, the seat size has to be limited in a seat width direction.  
         [0006]     A need thus exists for a vehicle seat position adjusting device in which a detection plate can be provided without space in a seat width direction being sacrificed.  
       SUMMARY OF THE INVENTION  
       [0007]     According to an aspect of the present invention, a vehicle seat position adjusting device includes a slide adjuster having a slide lock mechanism for slidably supporting a vehicle seat relative to a vehicle floor and holding the vehicle seat at a predetermined position relative to the vehicle floor by restricting a relative sliding movement of the vehicle seat relative to the vehicle floor, a reclining adjuster for rotatably supporting a seat back of the vehicle seat about a rotational axis line relative to a seat cushion of the vehicle seat, and a walk in mechanism disposed between the slide adjuster and the reclining adjuster for actuating the slide lock mechanism of the slide adjuster to allow the sliding movement of the vehicle seat relative to the vehicle floor when the seat back is rotated equal to or more than a predetermined angle relative to the seat cushion by operating the reclining adjuster. The walk in mechanism includes a detecting plate for detecting the predetermined angle or more than the predetermined angle rotation of the seat back relative to the seat cushion to the predetermined and the reclining adjuster includes a supporting surface arranged at an outer profile of the reclining adjuster in parallel to an extension direction of the rotational axis line of the seat back relative to the seat cushion. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawings, wherein:  
         [0009]      FIG. 1  shows a perspective view of the vehicle seat installed with a seat position adjusting device according to the invention;  
         [0010]      FIG. 2  shows a cross sectional view taken along the line II-II of  FIG. 1 ;  
         [0011]      FIG. 3  shows a perspective view of the walk in mechanism of the seat position adjusting device according to the invention;  
         [0012]      FIG. 4  shows a cross sectional view taken along the line IV-IV of  FIG. 1 ;  
         [0013]      FIG. 5  shows a view seen from the arrow C of  FIG. 4 ; and  
         [0014]      FIG. 6  shows a perspective view of the walk in mechanism of the seat position adjusting device according to the invention. 
     
    
     DETAILED DESCRIPTION  
       [0015]     As is illustrated in  FIG. 1 , the vehicle seat, positioned so as to be slidably supported by the seat adjuster  2  in a vehicle longitudinal direction relative to the vehicle floor (in a left and right direction in  FIG. 1 ), and so as to be capable of being supported at a predetermined longitudinal adjustment position, includes a seat cushion  3  that forms a seating surface and a seat back  4  that forms a reclining seat for the back. The seat back  4  is put into position by the reclining adjuster  5  at the rear portion of the seat cushion  3  so as to be rotatably supported in a vehicle longitudinal direction relative to the seat cushion  3 , and so as to be capable of being supported at a predetermined angle-adjustment position.  
         [0016]     As is illustrated in  FIG. 2  and  FIG. 3 , the seat slide adjuster  2  includes a lower rail  21 , an upper rail  22  and a lock plate  23 .  
         [0017]     The lower rail  21  is of an oblong shape extending in a longitudinal direction of the seat (the same direction as the vehicle longitudinal direction mentioned above), and front and rear end portions of the lower rail are fixed to the vehicle floor. In a cross section, the lower rail  21  assumes a substantially U-shape, and a pair of engaging flanges are formed on both the right and left ends of the cross section. The upper rail is of an oblong shape extending in a longitudinal direction, and is attached to the frame  31  of the seat cushion  3  (illustrated in  FIG. 1  and  FIG. 6 ). In a cross section, the upper rail  22  assumes a substantially reverse T-shape, and a pair of engaging flanges  22   a  are formed on both the right and left ends of the cross section. The upper rail  22  is made to engage with engaging flanges  21   a  of the lower rail  21  through balls  27 , and the upper rail  22  is slidably supported by the lower rail  21  in a longitudinal direction through rollers  28 . The end result of this is that the vehicle seat is slidably supported relative to the vehicle floor in a vehicle longitudinal direction.  
         [0018]     The lock plate  23  is rotatably supported in a width direction of the upper rail  22  (in a left and right direction in  FIG. 2 ) by a supporting shaft  24   a  supported by a bracket  24  fixed to the upper rail  22 . Multiple locking holes  21   b  are formed on the lower rail  21  in a longitudinal direction. An engaging hook  23   a,  capable of engaging with one of the lock holes  21   b,  are formed on the lock plate  23 , and, by virtue of engagement between the one of the lock holes  21   b  and the engaging hook  23   a,  sliding movement of the upper rail  22  relative to the lower rail  21  is restricted. In consequence, the vehicle seat  1  is supported at a predetermined longitudinal adjustment position relative to the vehicle floor. Further, on the lock plate  23 , an operating flange  23   b  that faces the engaging hook  23   a  is formed across the supporting shaft  24   a.  A first release lever  25 , rotatably supported by the upper rail  22  and extending in a longitudinal direction of the rail, is connected through the operating flange  23   b.  The first release lever  25  is connected at one end to an operating rod  26 , and at the other end pressing flange  25   a  is formed that presses the operating flange  23   b  of the lock plate  23 . Moreover, when the operating lever  25  is made to rotate, the pressing flange  25   a  press the operating flange  23   b  of the lock plate  23 , and the lock plate  23  rotates about the supporting shaft  24  in an anti-clockwise direction, as illustrated in  FIG. 2 . As a result, and as is illustrated by a broken line in  FIG. 2 , engagement between the engaging hook  23   a  of the lock plate  23  and the one of the lock holes  21   b  of the lower rail  21  is released. In consequence, the upper rail  22  becomes capable of sliding relative to the lower rail  21 . Moreover, because the upper rail  22  is made to slide relative to the lower rail  21  in a state where engagement between the engaging hook  23  and the one of the lock holes  21   b  has been released, the vehicle seat  1  is made to slide in a vehicle longitudinal direction relative to the vehicle floor. Further, the lock plate  23  is subjected to a biasing force of a spring (not illustrated in the drawings) provided around the supporting shaft  24   a,  and the engaging hook  23   a  are consistently biased in a clockwise direction, as illustrated in  FIG. 2 . Moreover, by virtue of a spring positioned between the upper rail  22  and the lower rail  21 , the upper rail  22  is also consistently biased so as to slide forward in a vehicle longitudinal direction relative to the lower rail  21 .  
         [0019]     As is illustrated in  FIG. 4  and  FIG. 5 , the reclining adjuster  5  includes a lower plate  6 , an upper plate  7  and three pawls  51 .  
         [0020]     The lower plate  6  is made of round-shaped board material and is fixed to the frame  31  of the seat cushion  3  by a process such as welding. Moreover, the upper plate  7  is also made of round-shaped board, and is fixed to the frame  41  of the seat back  4  by a process such as welding (as illustrated in  FIG. 1  and  FIG. 6 ).  
         [0021]     Protruding portion  61  is formed on the lower plate  6  by a process of pressing on an outer side (a right direction in  FIG. 4 ) of the lower plate  6  in a plate-thickness direction (a left-right direction in  FIG. 4 ). The protruding portion  61  form recessed receptacle portion  62  at the lower plate  6 , recessed receptacle portion  62  that faces an inner side of the lower plate  6  in a plate-thickness direction. Moreover, a protruding portion  71  (a projected portion) is formed on the upper plate  7  by a process of pressing on an inner side (left side in  FIG. 4 ) of the upper plate  7  in a plate-thickness direction (a left and right direction in  FIG. 4 ). This protruding portion  71  forms a recessed portion  72  on the upper plate  7 , on an outer side of the upper plate in a plate-thickness direction (the right side as illustrated in  FIG. 4 ). The recessed receptacle portions  62 ,  72 , respectively on the lower plate  6  and the upper plate  7 , are positioned so as to face one another. Thus, the lower plate  6  and the upper plate  7  are rotatably linked by a ring  8  to face one another at outermost circumferences. In this manner, the seat back  4  is rotatably supported in a longitudinal direction relative to the seat cushion  3 .  
         [0022]     The lower plate  6  and the upper plate  7  formed in this fashion thus form an internal void D in the shape of the recessed receptacle portions  62  and  72 . Moreover, the lower plate  6  rotatably supports a rotation shaft  52  around the rotational axis  0  that passes through the upper plate  7  by crossing an internal void D. The rotation shaft  52  supports a cam  53 , positioned in the internal void D, so as to rotate integrally.  
         [0023]     Three pairs of guiding surfaces  63  are formed, by a process of pressing, in an axial direction, a direction identical to that of a plate-thickness direction, and, moreover, an extending direction of the rotational shaft  52 , so as to protrude into the internal void D and face each other at predetermined distances, and so as to be positioned within the recessed receptacle portions  62 . These guiding surfaces  63  extend in a radial direction of the lower plate  6 . Moreover, a circumferential ratchet  73 , which protrudes into the internal void D in a radial direction, is formed, by a process of pressing, on the recessed portions  72  of the upper plate  7  so as to be disposed in the recessed receptacle portions  62 .  
         [0024]     The three pawls  51  are housed in the internal void D, are slidably guided relative to the guiding surfaces  63  of the lower plate  6  and are disposed so as to be capable of engaging with the circumferential ratchet  73  of the upper plate  7 , and so as to face the cam  53 . These pawls  51  are pressed from a rear surface by the cam  53  and engage with the ratchet  73 ; and, as a result of a cam interaction between cam elongated holes  51   a,  formed at the pawls  51 , and projections  53   a  that have been formed at the cam  53 , the pawls  51  slide along the guiding surfaces  63  by virtue of the rotation of the cam  53 . By virtue of the engagement between the pawls  51  and the ratchet  73  rotation of the upper plate relative to the lower plate  6  is controlled, and, in consequence, the seat back  4  is maintained at a predetermined inclining angle adjustment position relative to the seat cushion  3 .  
         [0025]     The rotation shaft  52  supports an operation lever  54  so as to rotate integrally. Moreover, when the operation lever is operated so as to rotate, the cam  53  rotates, together with the rotation shaft  52 , in a clockwise direction, as illustrated in  FIG. 5 ; pressing on the pawls  51  by the cam  73  is released, and the pawls  51  slide in a radial inner side direction along the guiding surfaces  63 . Thus, engagements between the pawls  51  and the circumferential ratchet  73  are released, and in consequence the upper plate  7  becomes capable of rotating relative to the lower plate  6 . Moreover, because the upper plate  7  is made to rotate relative to the lower plate  6  in a state where engagements between the pawls  51  and the circumferential ratchet  73  has been released, the seat back  4  rotates in a seat longitudinal direction relative to the seat cushion  3 . Further, the cam  53  is subjected to the biasing force of the spring  55  provided around the rotation shaft  52 , and the pawls  51  are consistently biased in a counter clockwise direction, as illustrated in  FIG. 5 , so as to press the pawls  51  and thus engage with the circumferential ratchet  73 . Further, the upper plate  7  is consistently subjected to a biasing force by a spring  56  provided between the upper plate  7  and the lower plate  6  so as to rotate in a seat forward direction relative to the lower plate  6 . A bracket  42  is fixed to the frame  41  of the seat back  4  for purposes of engaging the spring  56 .  
         [0026]     On the protruding portions  71  of the upper plate  7 , circumferential stoppers  74  are formed by a pressing process so as to be positioned on the inner side of the circumferential ratchet  73 , and thus capable of making contact with the pawls  51  in a circumferential direction, and the circumferential stoppers  74  are disposed within the recessed receptacle portion  62 . A maximum rotating angle of the upper plate  7  at the front of the seat relative to the lower plate  6 , and a maximum rotating angle of the upper plate  7  at the rear of the seat relative to the lower plate  6 , are both controlled as a result of the contact between the stoppers  74  and the pawls  51 .  
         [0027]     Because, during the formation of the recessed receptacle portion  62  the protruding portion  71  of the upper plate  7  is, as described above, formed by a pressing process of the circumferential ratchet  73  and the circumferential stoppers  74 , the external appearance of the protruding portion  71 , as is illustrated in  FIG. 4 , takes the form of round steps  71   c,  including a first horizontal surface  71   a  that follows an axial direction to relate to the circumferential ratchet  73 , and a second horizontal surface  71   b,  serving as a supporting surface, that follows an axial direction to relate to the circumferential stopper  74 .  
         [0028]     Next, an explanation will be offered of the walk-in mechanism  9  that links together the reclining adjuster  5  and the sliding seat adjuster  2 .  
         [0029]     As is illustrated in  FIG. 2  and  FIG. 3 , on an upper rail  22  of the sliding seat adjuster  2  a second release lever  91  is rotatably supported by a pin  91   b.  Opposite the second release lever  91 , a pressure pin  91   a,  which pressures the pressing flange  25   a  of the first release lever  25 , is provided between the operating flange  23   b  of the lock plate  23  and the pressing flange  25   a.  Further, as is illustrated in  FIG. 5  and  FIG. 6 , on an upper plate  7  of the reclining adjuster  5  a detection plate (a detecting plate)  92  is relatively and rotatably supported by the horizontal surface  71   b  of the protruding portion  71 . At this detection plate  92 , an engaging hook  92   a  is formed so as to protrude in a radial direction. This engaging hook  92   a  is positioned so as to engage with the bracket  42  of the frame  41  of the seat back  4 . When the upper plate  7  rotates at a predetermined angle in a seat forward direction relative to the lower plate  6 , the engaging hook  92   a  engages with the bracket  42 . At this time, the upper plate  7  and the detection plate  92  start to rotate together in an identical direction. Moreover, a rod  93  connects the second release lever  91  and the detection plate  92 , and the structure is such that the rotation of the detection plate  92  is transmitted to the second release lever  91  through the rod  93 .  
         [0030]     In this kind of configuration, when the operating lever  54  of the reclining adjuster  5  is operated, and engagements between the pawls  51  and the ratchet  73  are released, the seat back  4 , subjected to the biasing force of the spring  56 , rotates to a greater degree than a predetermined angle in a seat forward direction relative to the seat cushion  3 , the bracket  42  engages with the engaging hook  92   a  of the detection plate  92  and, together with the upper plate  7 , the detection plate  92  rotates in a clockwise direction, as illustrated in  FIG. 6 . In consequence, the rod  93  is pulled back in a seat rearward direction and the second release lever  91  rotates in a clockwise direction, as illustrated in  FIG. 3 . The rotation of the second release lever  91  is achieved by rotating the lock plate  23  in an anti-clockwise direction, as shown in  FIG. 2 , through the pressing flange  25   a  of the first release lever  25 , and engagement between the engaging hook  23   a  of the lock plate  23  and the lock hole  21   b  of the lower rail  21  is thereby released. In consequence, the vehicle seat is subjected to the biasing force of the spring and slides in a vehicle forward direction relative to the vehicle floor.  
         [0031]     As has been described above, the detection plate  92  of the walk-in mechanism  9  is supported by the second horizontal surface  71   b  of the upper plate  7  of the reclining adjuster  5 , and the reclining adjuster  5  and the detection plate  92  are positioned on an identical surface in an axial direction. In consequence, in comparison with related art, it is possible to position the detection plate  92  without space in an axial direction being sacrificed, and it is thus possible to use effectively the space within a vehicle compartment. Further, because the second horizontal surface  71   b  that supports the detection plate  92  is formed within the protruding portions  71  that form the recessed receptacle portions  72  of the upper plate  7 , special processing does not need to be carried on the upper plate  7  for the detection plate  92  to be supported by the upper plate  7 , and it is accordingly possible to achieve a simple structure at a modest cost.  
         [0032]     In the configuration of this embodiment, the detection plate  92  is supported by the second horizontal surface  71   b  of the upper plate  7 , but it is also possible for the detection plate  92  to be supported by the first horizontal surface  71   a,  or, alternatively, by the outer circumferential surface of the ring  8  and the outer circumferential surface of the protruding portion  61  of the lower plate  6 .  
         [0033]     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.