Supporting structure and seat apparatus having a retractable seat
A seat apparatus include: a shaft rotated by a motor and operatively associated with the seat so as to move the seat; a first leg secured to the shaft and pivotably supported by the seat; a first spring, one end of which is fixedly attached to the shaft and an other end of which is fixedly attached to the seat; the first spring which biases the shift in a first direction; and a second spring, one end of which is fixedly attached to the shaft and an other end of which is fixedly attached to the seat, the second spring which biases the shaft in a second direction. The first direction opposes to the second direction.
1. A seat apparatus comprising;
a shaft rotatable by a motor and operatively associated with a seat so as to move the seat;
a first leg secured to the shaft and pivotably supported by the seat;
a first spring, one end of which is fixedly attached to the shaft and another end of which is fixedly attached to the seat, the first spring biasing the shaft in a first rotational direction; and
a second spring, one end of which is fixedly attached to the shaft and another end of which is fixedly attached to the seat, the second spring biasing the shaft in a second rotational direction which is opposite to the first rotational direction.
2. A seat apparatus according to claim 1 further comprising:
a link mechanism which operatively supports the seat on a stationary portion, the link mechanism having a first link pivotably supported by the seat and the stationary portion and a second link, one end of which is secured to the first leg and another end of which is pivotably supported by the stationary portion, the first leg being rotated in response to rotation of the shaft.
3. A seat apparatus comprising:
a link mechanism operatively mounted on a stationary portion and operatively supporting a seat, the link mechanism being driven by a driving unit so that the link mechanism shifts the seat between a first position and a second position;
a first biasing member biasing the link mechanism in a first direction to assist the driving unit in moving the seat from the first position to the second position; and
a second biasing member biasing the link mechanism in a second direction opposite to the first direction so as to restrain the driving unit from moving the seat from the first position to the second position.
4. A seat apparatus according to claim 3 , wherein the first biasing member biases the link mechanism in a direction to restrain the driving unit from moving the seat between the second position and the first position, and the second biasing member biases the link mechanism in the direction of the first biasing member so as to assist the driving unit in moving the seat from the second position to the first position.
5. A seat apparatus according to claim 3 , wherein the first biasing member and the second biasing member are both springs.
6. A seat apparatus according to claim 3 , wherein the link mechanism comprises a first link, which is pivotably supported by the seat and the stationary portion, and a second link, which is pivotably supported by the seat and the stationary portion.
7. A seat apparatus according to claim 6 , wherein the driving unit includes a motor and a shaft rotated by a torque of the motor, and at least one of the first link and the second link is operated in response to rotation of the shaft.
8. A seat apparatus according to claim 7 , wherein the first biasing member is a first torsion spring, one end of which is fixedly attached to the shaft and another end of which is fixedly attached to the seat, and the second biasing member is a second torsion spring, one end of which is fixedly attached to the shaft and another end of which is fixedly attached to the seat, and
wherein, when the seat is shifted from the first position to the second position, the first torsion spring biases the shaft in the same direction as a rotational direction of the shaft and the second torsion spring biases the shaft in an opposite direction to the rotational direction of the shaft.
9. A seat apparatus according to claim 8 , wherein, when the seat is shifted from the second position to the first position, the first torsion spring biases the shaft in an opposite direction to a rotational direction of the shaft and the second torsion spring biases the shaft in the same direction as the rotational direction of the shaft.
10. A seat apparatus according to claim 8 , wherein the first torsion spring and the second torsion spring are coiled on the shaft.
11. A seat apparatus according to claim 7 , wherein the driving unit is attached to the seat.
12. A seat apparatus according to claim 7 , further comprising:
a first leg rotated by the shaft and operatively attaching the seat to the stationary portion,
wherein the second link supports the seat via the first leg.
13. A seat apparatus according to claim 12 , further comprising:
a leg, which is different from the first leg, operatively attaching the seat to the stationary portion, wherein the first leg is positioned at a rear portion of the seat and the leg is positioned at a front portion of the seat; and
a cable connecting the first leg and the leg.
14. A seat apparatus according to claim 13 , wherein the second link is rotated in response to rotation of the first leg by the shaft, and the cable is fixed to a bracket secured to the shaft.
15. A seat apparatus according to claim 13 , wherein the leg is pulled in one direction by a tension of the cable to be rotated.
16. A seat apparatus comprising:
a link mechanism rotatable by a motor and associated with a seat which freely rotatably supports the seat;
a first leg secured to the link mechanism and pivotably supported by the seat;
a first spring which biases the link mechanism in a first rotational direction; and
a second spring which biases the link mechanism in a second rotational direction opposite to the first rotation direction.
17. A seat apparatus according to claim 3 , wherein the stationary portion is a floor of a vehicle.
18. A seat apparatus according to claim 16 , wherein the stationary portion is a floor of a vehicle.
19. A seat apparatus according to claim 1 further comprising:
a second leg secured to the shaft and pivotably supported by the seat, wherein the first spring and the second spring are provided between the first leg and the second leg.
20. A seat apparatus according to claim 19 further comprising:
a four link mechanism which operatively supports the seat on a floor and having a first link, a second link, a third link and a fourth link,
wherein the first link is pivotably supported by the seat and the floor, the third link is pivotably supported by the seat and the floor, one end of the second link is secured to the first leg and another end of the second link is pivotably supported by the floor, one end of the fourth link is secured to the second leg and another end of the fourth link is pivotably supported by the floor, and the first leg and the second leg are rotated in response to rotation of the shaft.