Abstract:
A seat device equips a walk-in mechanism and a fold down mechanism (a seatback is turned down with large angle so as to attain the flat condition). These mechanisms can be operated selectively using a simple operation without using plural levers. A base bracket of the seat device is fixed to a lower arm. The base bracket has a stopper and pivotally supports the first link member and the second member in a freely turning way. An upper arm has a contact portion. If the upper arm is turned down in the forward direction for the walk-in operation, the contact portion gets in contact with an intervening member of the first link member so as not to turn further down in the forward direction. In the case that the seatback is turned to the flat condition, the intervening member is moved towards the outside portion of the locus of movement of the contact portion. Consequently, the contact portion of the upper arm can be turned down on a large scale without getting in contact with the intervening member.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based on and claims priority under 35 U.S.C. § 119 with respect to Japanese Application No.2001-391883 filed on Dec. 25, 2001, and the entire content of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention generally relates to a vehicle seat device equipped with a walk in mechanism.  
       BACKGRUND OF THE INVENTION  
       [0003]     This invention generally relates to a seat device having a fold down mechanism (turning down mechanism of a seatback in the forward direction over a seat cushion) and a walk-in mechanism.  
         [0004]     Conventionally, a walk-in mechanism is installed in a seat device of two-door type vehicle. The walk-in mechanism works to unlock a lock mechanism of a seat position adjusting mechanism of the front seat, when a seatback of a front seat is turned forward. And the front seat is released to move in forward direction for making an entry of a passenger on to or off from the rear seat easy.  
         [0005]     Also for the seat device of a two-door type vehicle, the fold down mechanism is installed. The fold down mechanism works to make the back surface of the front seat back on the same height level with the baggage storage space, and a rear space of vehicle be utilized easily for baggage storage. The cushion of a front seat is turned up and moved forward around a hinge of the front portion thereof, then the seatback of the front seat is forwardly turned down to the space where the cushion was.  
         [0006]     An example of a seat device equipped with these mechanisms is disclosed in a PCT international publication numberWO 99/38723. This publication discloses the first lever for operating the walk-in mechanism and the second lever for operating the fold down mechanism. Accordingly, the levers are selected and operated according to the each function.  
         [0007]     In the conventional seat device described above, since the two levers have to be operated for the walk-in and the fold down mechanism selectively, operation miss may happen. Once such operation miss happens, restoring the cushion and the seatback position to a normal position is made to be difficult.  
         [0008]     Therefore, the object of the present invention is to solve the inconvenient operation of the conventional technology by utilizing one operational lever and to avoid the aforementioned drawback.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention is related with a seat device including an upper arm which can be turned in forward and backward directions around a lower arm, comprising contact portion provided in said upper arm, base bracket fixed to said lower arm and having a stopper, first link member pivotally supported by said base bracket and having an intervening portion, and an activating member for activating said first link member, wherein the intervening portion provided on the first link member is moved within a locus of movement of said contact portion when a walk-in operation is performed and the intervening portion is moved out from the locus of said movement by activating the activating member when a seatback is turned down in forward direction with large angle.  
         [0010]     In accordance with the present invention, an activating member can move the intervening portion towards within or out of the locus of movement of the contact portion by operating a lever or engagement with the cushion. The position of the upper arm can be easily selected in accordance with the walk-in or fold down operation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0011]     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 drawing Figures wherein:  
         [0012]      FIG. 1  is an exploded perspective view of a seat device of the first aspect of the present invention;  
         [0013]      FIG. 2  is a side view that indicates respective part positions of the first aspect of the present invention at the time of seating;  
         [0014]      FIG. 3  is a side view that indicates respective part positions of the first aspect of the present invention at the time of performing a walk-in operation;  
         [0015]      FIG. 4  is a side view that indicates respective part positions of the first aspect of the present invention when cushion material is removed;  
         [0016]      FIG. 5  is a side view that indicates respective part positions of the first aspect of the present invention when a seatback is turned in the flat direction;  
         [0017]      FIG. 6  is a side view that indicates a seat position of the second aspect of the present invention;  
         [0018]      FIG. 7  is a side view that indicates respective part positions of the second aspect of the present invention at the time of performing the walk-in operation;  
         [0019]      FIG. 8  is a side view that indicates respective part positions of the second aspect of the present invention when the seatback is turned down in the forward direction on a large scale; and  
         [0020]      FIG. 9  is a side view that indicates respective part positions of the second aspect of the present invention when the seatback is turned in the flat direction. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     The embodiment of the present invention is explained hereinafter with reference to drawings.  
         [0022]      FIG. 1  is an exploded perspective view of the first embodiment of a seat device according to the invention.  
         [0023]     A lower arm  2  forming a part of a seat cushion of a seat device  1  supports an upper arm  3  forming a part of seatback in a declining or reclining manner about a pin  4  in forward and backward directions.  
         [0024]     In the Fig.s, only one side of a symmetrically disposed pair of the lower arm  2  and upper arm  3  is indicated. A pin  4  supports a rotary member  5  which is made of a plate having a approximately triangle shape, and the rotary member  5  has a contact portion  5   a  and is rotatable about the pin  4  fixedly together with the upper arm  3 .  
         [0025]     A base bracket  6  is fixed on an inside surface of the lower arm  2  by utilizing bolts  7 ,  7   a ,  8  and corresponding nuts  7   b ,  7   c ,  8   b . The base bracket  6  is positioned under the upper arm  3 . The base bracket  6  has a stopper portion  10  facing to the inside surface of the upper arm  3  with a space, a hook segment  12  for supporting one end of a coil spring  11 , and a supporting segment  15  for accepting an end support portion  14  of a cable  13 . The first link member  17  and the second link member  18  are pivotally supported by a pin  16  in a lower position than the stopper portion  10 . The stopper portion  10  has a shape of “L”.  
         [0026]     The first link member  17  has a shape of bell crank and supports pins  18   a  and  19  on both free end portions of the first link member  17 . One end portion of the spring  11  is engaged with one of both free end portions. Consequently, the first link member  17  is biased by the spring  11  to turn in counterclockwise direction around the pin  16 .  
         [0027]     The second link member  18  has a long hole  20  nearly in the middle portion thereof, and accepts the pin  19 . The pin  16  penetrates one end portion of the second link member  18 , and the other end portion of the second link member  18  is connected with the end portion of the cable  13 .  
         [0028]     The other end portion of the cable  13  is connected with a lock mechanism (not shown) for adjusting the seat position in forward and backward.  
         [0029]     A sensor link member  21  extending in forward direction is pivotally supported by a pin  9  on the base bracket  6 . The sensor link member  21  has a contact bar  22  on the front end portion thereof. The contact bar  22  extends perpendicularly upward from the sensor link member  21 , and the upper end of contact bar  22  is opposed to the bottom surface of the seat cushion  23 . A connecting surface  23   a  formed on the rear end portion of the sensor link member  21  is opposed to the pin  19  on the first link member  17 . The pin  19  is inserted into the long hole  20  of the second link member  18 .  
         [0030]     As shown in  FIG. 2 , when a cushion  23  is set in sitting position, the seat cushion  23  pushes the contact bar  22  downward, and the sensor link member  21  is turned in counterclockwise direction around the pin  9 . The connecting surface  23   a  pushes the pin  19  in upward direction. Accordingly, the first link member  17  turns in clockwise direction around the pin  16  against the force of the spring  11  and the pin  19  turns until the pin  19  gets in contact with the upper end portion of the long hole  20 . Then, as shown in  FIG. 2 , the pin  18   a  of the first link member  17  comes within a locus of turn of the contact portion  5   a  of the rotary member  5 .  
         [0031]     In  FIG. 3 , the seat device in a walk-in operation condition is indicated. When the seatback is turned in forward direction for the walk-in operation, the upper arm  3  turns in counterclockwise direction, the contact portion  5   a  of the rotary member  5  gets in contact with the pin  18   a , the pin  18   a  is moved in the same direction with the contact portion  5   a , and the pin  18   a  also gets in contact with the stopper portion  10  of the base bracket  6 . Accordingly, the movement of the upper arm  3  is stopped by the stopper portion  10  and maintained in the walk-in position as shown in  FIG. 3 .  
         [0032]     The first link member  17  with the pin  18   a , as an intervening member to transfer the movement of the upper arm  3  to the cable  13 , is turned in clockwise direction around the pin  16 . Then, the second link member  18  is turned in the same direction with the first link member  17  by the pin  19 . Consequently, the cable  13  is pulled, and the lock mechanism (not shown) is released, as a result the front seat position can be moved in forward direction.  
         [0033]     As shown in  FIG. 4 , for the fold down operation, the seat cushion  23  is held up from the seating position by rotating the seat cushion  23  around a hinge portion (not shown in the drawing) located on a front portion thereof.  
         [0034]     By holding up the seat cushion  23 , the contact bar  22  is released from the contact on the bottom surface the seat cushion  23 , and the first link member  17  is turned around the pin  16  in counterclockwise direction by the spring  11 . The pin  19  moves down the connecting surface  23   a  and the sensor link member  21  turns in clockwise direction around the pin  9 .  
         [0035]     The rotation of the first link member  17  in counterclockwise direction is limited by engagement of the pin  19  on the end portion of the long hole  20 . When the first link member  17  is stopped, the pin  18   a  is positioned outside the locus of the turn of the rotary member  5 , and the walk-in is not operated.  
         [0036]     As shown in  FIG. 5 , the seatback is turned in forward direction with large angle, the pin  18   a  gets out of the locus of the contact portion  5   a  of the rotary member  5  and thus the rotary member  5  can turn backward without engaging with the stopper portion  10  of the base bracket  6 . Consequently, the seatback can be folded down to a flat position where the seat cushion was.  
         [0037]     Accordingly, it becomes easy to load in or unload a baggage on or from the space behind the seat.  
         [0038]     As shown in  FIG. 3 , when the walk-in operation is completed, and after the passenger sits on or get out from the rear seat, the seatback is restored in backward to the seating position. In this operation, following the movement of the rotary member  5 , the pin  18   a  moves by the spring  11 , and the position of each member is restored to the condition shown in  FIG. 2 .  
         [0039]     When the seatback is moved back to the seating position from the fold down condition shown in  FIG. 5 , the condition shown in  FIG. 4  is restored. Then, the condition of  FIG. 2  is restored, when the seat cushion  23  is set in the seating position.  
         [0040]     The a second embodiment according to this invention is shown in FIGS.  6  to  9 . Step portions  25  and  26  as contact portions are formed in the circumferential surface of the end portion of an upper arm  24 , and a small circumferential surface  28  with a radius from a center point of a pin  27  is formed.  
         [0041]     A projecting portion  30  positioned in the side (the outside portion of a locus) portion of the turning locus of the step portion  25  and a base bracket  32  having a stopper  31  positioned within the locus are fixed to a lower arm  29 . The base bracket  32  has a long hole  33 .  
         [0042]     The central point of the first link member  34  having the shape of “L” is pivotally supported by a pin  35  on the base bracket  32 .  
         [0043]     A roller  36  which can roll on circumferential surface  28  is installed on one end of the first link member  34 . A cable  37  is connected to the other end of the first link member  34 .  
         [0044]     A spring  41  is connected to the base bracket  32  on the one end thereof, and the other end is connected to the first link member  34 . Thus, the first link member  34  is biased to turn in clockwise direction, and the rolling of the roller  36  on the circumferential surface  28  is maintained.  
         [0045]     A cable  37  is connected to a fold down lever (not shown) installed in the seatback.  
         [0046]     One end of the second link member  38  is pivotally supported by the first link member  34  by a pin  39  at a portion between the pin  35  and the roller  36 , and a pin  40  disposed on the other end of the second link member  38  is inserted in the long hole  33 .  
         [0047]     When the seat device is set in a seating position as shown in  FIG. 6 , the roller  36  contacts on the circumferential surface  28  and also contacts on a projecting portion  30 . A pin  40  is located in a lower position of the long hole  33 .  
         [0048]     As shown in  FIG. 7 , when the seatback is turned down in the forward direction for the walk-in operation, since the step portion  25  gets in contact with the roller  36 . Since the movement of the roller  36  is stopped by the projecting portion  30 , the seatback is also stopped and maintained in the position shown in  FIG. 7 . In this operation, the step portion  25 , the projecting portion  30 , and the roller  36  function as stoppers for stopping the movement of the seatback.  
         [0049]     In order to achieve a fold down condition, that is to say, to make the seatback be in the flat condition by large turning angle of the seatback in the forward direction, a seat cushion (not shown) is held up by rotating around a hinge portion located on a front portion thereof. Then an operation lever (not shown) is pulled and the cable  37  is pulled, then the first link member  34  turns in counterclockwise direction around the pin  35  against the force of the spring  41  and the roller  36  is rotated with large angle and moved outside of the locus of the step portion  25 . The second link member  38  is guided by the long hole  33  and moved to the position shown in  FIG. 8  in accordance with the movement of the first link member  34 .  
         [0050]     When the operation lever is released in the condition shown in  FIG. 8 , the pin  40  of the second link member  38  is engaged in a shallow concave portion  33   a  formed on an end portion of the long hole  33  and the position of the second link member  38  is maintained.  
         [0051]     When the seatback is turned down in forward direction with large angle, the step portion  25  passes by the side surface of the projecting portion  30  and moves in counterclockwise direction, and the step portion  25  pushes a pin  40  in clockwise direction. The step portion  25  gets in contact with the side of the stopper  31  positioned within its locus, and thus the movement of the upper arm  24  is controlled. Since the step portion  25  gets in contact with the stopper  31 , the flat condition of the seatback is maintained.  
         [0052]     When the position of the seatback of  FIG. 7  is restored to the seating position after the walk-in operation, the roller  36  gets in contact on the projecting portion  30  and the seating condition shown in  FIG. 6  is restored.  
         [0053]     When the seatback is turned back from the condition shown in  FIG. 9 , that is from the flat condition, the condition shown in  FIG. 8  is restored. In this operation, the first link member  34  is turned in clockwise direction by the spring  41 , and then the roller  36  comes to get in contact with and slide on the circumferential surface  28 .  
         [0054]     In the embodiments shown in FIGS.  6  to  9 , a pair of the first link members  34 , and a pair of the second link members  38  and a pair of the base bracket  32  are preferably provided on the both sides of the upper arm  24 , and the each first link member  34 , each second link members  38  are connected by the pin  35  and the roller  36 . Then, the cable  37  is connected to one of the first link member  34 . In such a structure, the load applied on the roller  36  can be supported by the pair of the first link members  34 . And when the seatback is in the flat condition as shown in  FIG. 9 , the load applied by the step portion  25  on the stopper portions  31  can be dispersed to the pair of base brackets  32 .  
         [0055]     As obviously indicated in the first and second embodiments of the Fig.s, by holding up the seat cushion or by operating the lever, the pin or the roller which functions as an intervening portion can be moved out of the turning locus of the step portion formed on the upper arm or the turning member of the upper arm. Accordingly, the seatback can be turned down in the forward direction, and the seatback can be turned in the flat direction easily.