Abstract:
A seat for a vehicle includes a base member provided on the seat and including a groove in which a striker is received and from which the striker is extracted, a hook member rotatably connected to the base member, a lever rotatably connected to the hook member, and a switch that can be in contact with the lever; wherein the lever activates the switch when the striker is received in the groove and whose movement is prohibited by the hook member.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is based on and claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2005-088256, filed on Mar. 25, 2005, the entire content of which is incorporated herein by reference. 
   FIELD OF THE INVENTION 
   This invention generally relates to a seat for a vehicle. More particularly, the invention pertains to a seat for a vehicle including a lock device. 
   BACKGROUND 
   In order to ensure a vehicle interior space for luggage, passengers, and the like, a seat back folded down onto a seat cushion and the seat cushion are stowed into a space on a vehicle floor located on a front side or a rear side of the seat in a vehicle longitudinal direction. Such the vehicle seat is disclosed in JP2003-118451A. A known retractable vehicle seat may include right and left front legs in a vehicle width direction and rotatably connected to respective front portions on right and left sides of a seat cushion frame, and right and left rear legs in the vehicle width direction and rotatably connected to respective rear portions on right and left sides of the seat cushion frame. The vehicle seat may be normally in a seating position as the pair of front legs engage with respective strikers provided on the vehicle floor by means of each lock device including a latch and a pawl. 
   According to such the lock device, in order to detect a locked state of the latch, at least two detection switches are provided in the vicinity of the latch so that a large gray zone in the system can be addressed. 
   However, usage of two or more detection switches requires a complicated controller for the process conducted by the detection switches and may be uneconomical. 
   Thus, a need exists for a seat for a vehicle that can provide a simple structure and achieve cost reduction. The present invention has been made in view of the above circumstances and provides such a device. 
   SUMMARY OF THE INVENTION 
   According to an aspect of the present invention, a seat for a vehicle includes a base member provided on the seat and including a groove in which a striker is received and from which the striker is extracted, a hook member rotatably connected to the base member, a lever rotatably connected to the hook member, and a switch that can be in contact with the lever. The lever activates the switch when the striker is received in the groove and whose movement is prohibited by the hook member. 
   According to another aspect of the present invention, a seat for a vehicle in which a seat cushion and a seat back folded down onto the seat cushion are stowed into a storage space formed on a floor of the vehicle includes a front leg for supporting a front portion of the seat cushion, a rear leg provided on a rear portion of the seat cushion and including a lock member engaging with an engaging member provided on the floor of the vehicle, a groove formed on the front leg for receiving a striker, a hook member rotatably connected to the front leg and for opening or closing an opening portion of the groove, a lever rotatably connected to the hook member, and a switch supported on the front leg and activated by the lever. 
   According to further another aspect of the present invention, a seat for a vehicle includes a leg for supporting the seat and including a groove for receiving a striker, a hook member rotatably connected to the leg and for opening or closing an opening portion of the groove, a lever rotatably connected to the hook member, and a detecting unit activated by the lever. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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: 
       FIG. 1  is a front view of a vehicle seat according to an embodiment of the present invention; 
       FIG. 2  is a front view showing a usage example of a stranded cable; 
       FIG. 3  is a plane view showing a front leg, a rear leg and the stranded cable; 
       FIG. 4  is a plane view showing a state immediately before a striker enters into a groove of the front leg or a base member; 
       FIG. 5  is a plane view showing a state in which the striker enters into the groove of the base member or the front leg; 
       FIG. 6  is a plane view showing a state in which the striker pushes a lever; 
       FIG. 7  is a plane view showing an engaging state between the hook member and the striker; 
       FIG. 8  is a plane view showing a state in which the striker pushes the lever to thereby activate a detection switch; and 
       FIG. 9  is a plane view showing a state in which the hook member is moved to an unlocked position by means of an actuator. 
   

   DETAILED DESCRIPTION 
   An embodiment of the present invention is explained with reference to the attached drawings. As shown in  FIG. 1 , a vehicle seat  1  includes a seat cushion  2  and a seat back  3 . The seat cushion  2  is supported on a floor  4  by means of right and left front legs  9  and right and left rears leg  10  in a vehicle width direction. The front leg  9  and the rear leg  10  respectively include lock devices  7  and  8  engageable with respective strikers  5  and  6  provided on the floor  4  of the vehicle. A supporter  11  of the seat cushion  2  has a four-link mechanism. Precisely, the supporter  11  is constituted by a pair of first links  12  arranged on both sides of the seat cushion  2  in the vehicle width direction, and a pair of second links  13  also arranged on both sides of the seat cushion  2  in the vehicle width direction, i.e. four parallel links. One end of each first link  12  is supported by a pivot axis  14  of a seat cushion frame  2 ′ (see  FIG. 3 ) of the seat cushion  2  while the other end of each first link  12  is supported by a pivot axis  16  provided within a seat storage space  15 . In addition, one end of each second link  13  is secured to the rear leg  10  while the other end of each second link  13  is supported by a pivot axis  17  provided within the seat storage space  15 . 
   A shaft  18  for rotatably supporting the rear leg  10  relative to the seat cushion frame  2 ′ is rotated by an electric motor  19  that is retained by the seat cushion frame  2 ′ as shown in  FIG. 3 . The operation of the electric motor  19  causes the shaft  18  to rotate, which leads to rotation of the rear leg  10  secured to the shaft  18  and the second link  13  secured to the rear leg  10  relative to the seat cushion  2 . 
   As shown in  FIG. 3 , a bracket  20  is secured to an end portion of the shaft  18 . A portion provided on a lower side of a pivot axis  21  (see  FIG. 2 ) for supporting the front leg  9  relative to the seat cushion frame  2 ′, and the bracket  20  are connected to each other by means of a stranded cable  22 . The front leg  9  is biased in a clockwise direction in  FIG. 2  by a spring  23 , however, movement of the front leg  9  is restricted by a stopper  24 . 
   As shown in  FIGS. 2 and 3 , the lock device  7  provided at the front leg  9  (base member) includes a hook member  25  rotatably connected to the front leg  9 , a lever  26  rotatably connected to the hook member  25 , and a detection switch  27  (detecting unit) having a contact point that faces a free end portion  26   b  (second engaging portion) (see  FIG. 4 ) of the lever  26 . The hook member  25  and the lever  26  are biased by a first spring  100  and a second spring  101  (see  FIG. 4 ) respectively such that the hook member  25  and the lever  26  are specified in a locked position as shown in  FIG. 2 . The first spring  100  biases the hook member  25  in a counterclockwise direction while the second spring  101  biases the lever  26  in a clockwise direction. A pivot axis  35  (rotation center) of the hook member  25  and a pivot axis  36  (rotation center) of the lever  26  are positioned in an offset manner as shown in  FIG. 4 . The striker  5  formed on the floor  4  of the vehicle enters along with a tapered face  29  into a groove  28  formed on a free end of the front leg  9 . Precisely, the striker  5  makes contact with a tapered face  30  of the hook member  25  and then causes the hook member  25  to rotate in a clockwise direction against a biasing force of the first spring  100  so that the striker  5  enters into the groove  28 . Next, the striker  5  rotates the lever  26  in a counterclockwise direction, which causes the free end portion  26   b  of the lever  26  to activate the detection switch  27 . The detection switch  27  outputs a signal indicating that a locked state shown in  FIG. 1  is obtained. 
   The lock device  8  provided at the rear leg  10  includes a latch  31  and a pawl  32 , which are biased in one direction by a spring (not shown) when the pawl  32  and the latch  31  disengage from each other. The pawl  32  engages with the latch  31  by receiving a biasing force of the spring in case of a locked state shown in  FIG. 2 . A groove  33  is formed on the latch  31 . 
   Next, a storage operation of the vehicle seat  1  is explained below. When an operation switch for stowing the seat  1  is turned to the ON position, the seat back  3  is folded forward. While the seat back  3  is folded forward, an actuator (not shown) is turned to the ON position so that the pawl  32  and the latch  31  of the lock device  8  are both rotated in the counterclockwise direction. The engagement between the striker  6  and the latch  31  are released accordingly. In addition, the electric motor  19  is driven so as to operate the shaft  18 . Then, the rear leg  10  is rotated in the clockwise direction relative to the shaft  18 , and the bracket  20  is also rotated in the clockwise direction. The rotation of the bracket  20  in the clockwise direction causes the stranded cable  22  to be pulled in an arrow A direction in  FIG. 2  so that the front leg  9  is rotated in the counterclockwise direction relative to the pivot axis  21  of the front leg  9 . The movement of the front leg  9  causes the striker  5  to push a tapered face  34  of the hook member  25  so as to rotate the hook member  25  in the clockwise direction. Then, the striker  5  is extracted from the groove  28 , which leads to an unlocked state of the front leg  9 . In this case, an actuator can be used for forcedly moving the hook member  25  in an unlocked position. 
   With the operation of the electric motor  19 , the free ends of the respective legs  9  and  10  move in a direction so as to approach each other, and at the same time the rear leg  10  and the second link  13  connected as a unit thereto are rotated in the clockwise direction relative to the pivot axis  17 . The vehicle seat  1  is stowed in the storage space  15  as shown by an imaginary line in  FIG. 1  by the supporter having the four-link mechanism. 
   An example of the lock device  7  used in the front leg  9  of the foldable seat has been explained above with reference to  FIGS. 1 to 3 . However, the lock device  7  is applicable to not only the front leg  9  for the seat but also to a sliding door and the like. Accordingly, explanation for the case where the lock device  7  is used in a base member  9  is shown below. As shown in  FIG. 4 , when the striker  5  enters into the groove  28  along with the tapered face  29  of the base member  9 , the striker  5  makes contact with the tapered face  30  of the hook member  25 . Then, the hook member  25  is rotated in the clockwise direction relative to the pivot axis  35  against a biasing force of the spring  100  (see  FIG. 2 ). The striker  5  can further enter into the groove  28  accordingly. 
   As shown in  FIG. 5 , the striker  5  that has entered into the groove  28  makes contact with a free end portion  26   a  (first engaging portion) on one end of the lever  26 , thereby causing the lever  26  to rotate in the counterclockwise direction relative to the pivot axis  36 . The lever  26  is rotatably supported on the hook member  25  by means of the pivot axis  36 . When the striker  5  further enters into the groove  28 , the striker  5  causes the lever  26  to further rotate in the counterclockwise direction as shown in  FIG. 6 . The free end portion  26   b  on the other end of the lever  26  makes contact with the contact point of the detection switch  27 , i.e. an arm  37 , which leads to the ON state of the detection switch  27  and the locked state in which the hook member  25  closes an opening portion of the groove  28  of the base member  9 .  FIGS. 7 and 8  show the locked state. An elastic silencer is provided within the groove  28  for the purposes of preventing occurrence of sound caused by contact between the striker  5  and the hook member  25  or the lever  26 . 
   When the detection switch  27  verifies that the striker  5  and the hook member  25  are brought in the locked state as shown in  FIG. 8 , the detection switch  27  outputs a signal indicating that the locked state is obtained.  FIG. 9  is a view showing that the hook member  25  is rotated by an operation of an actuator  200  (i.e. the actuator  200  is turned to the ON position) in the clockwise direction to the unlocked position relative to the pivot axis  35 . In the unlocked state, the hook member  25  can be separated from the striker  5  by the movement of the base member  9  in an upward direction in  FIG. 9  or by the movement of the striker  5  in a downward direction in  FIG. 9 . With the actuator  200  turned to OFF position, the hook member  25  and the lever  26  rotatably supported on the hook member  25  can return to a state shown in  FIG. 4  by means of the spring  100 . 
   According to the aforementioned embodiment, the lock device  7  basically includes the single detection switch  27 , the hook member  25 , and the lever  26  rotatably connected to the hook member  25 . Since the lever  26  is roratably connected to the hook member  25  and the lever  26  is operated with the detection switch  27 , an angle of the hook member  25  and a presence of the striker  5  can be detected by the single detection switch  27  through the lever  26 . A reduced cost of the device may be achieved accordingly. 
   Further, according to the aforementioned embodiment, the lever  26  is rotatably connected to the hook member  25  and the hook member  25  is rotatably attached to the base member  9  or the front leg  9  of the seat  1 . Thus, a small installation space can be obtained. 
   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.