A vehicle seat of retractable type in combination with a vehicle floor including an upper floor area and a lower floor area, which is retractable from an upper use position on said upper floor area to a lower storage position on said lower floor area, or vice versa, comprising:
- a basic seat unit comprising a seat cushion and a seat back rotatably connected with said seat cushion, wherein said seat back is foldable down onto said seat cushion to provide a folded state of said basic seat unit, said basic seat unit having a forward portion facing to a forward side of said vehicle seat, and a backward portion facing to a backward side of said vehicle seat;
- a rotary support link mechanism operatively connected between said basic seat unit and said vehicle floor so as to allow displacement of the basic seat unit between said upper use position and said lower storage position, said rotary support link mechanism comprising;
- at least one forward link element having:
- an upper pivotal support point pivotally connected with said forward portion of said basic seat unit;
- and a lower pivotal support point pivotally connected with said lower floor area, said at least one forward link element being rotatable relative to the lower pivotal support point thereof in one of a forward direction to the forward side of said vehicle seat and a backward direction to the backward side of said vehicle seat;
- at least one backward link element having:
- an upper pivotal support point pivotally connected with said backward portion of said basic seat unit;
- and a lower pivotal support point, said at least one backward link element being rotatable relative to the lower pivotal support point thereof in one of a forward direction to said forward side of said vehicle seat and a backward direction to said backward side of said vehicle seat;
- and
- said at least one backward link element being smaller in length than said at least one forward link element, whereby a distance between said upper and lower pivotal support points of said at least one forward link element is different from a distance between said upper and lower pivotal points of said at least one backward link element,
- wherein said lower pivotal support point of said at least one backward link element is disposed backwardly of and above said lower pivotal support point of said at least one forward link element,
- with such an arrangement that, when said basic seat unit is set in said upper use position, said at least one forward link element is inclined toward said backward side of said vehicle seat at a backward inclination angle, whereas said at least one backward link element is inclined toward said backward side of said vehicle seat at a backward inclination angle which is smaller than said backward inclination angle of said at least one forward link element, whereby said basic seat unit is normally set in a substantially horizontal state upon said upper floor area;
- a drive element including a motor and a driving shaft which is operatively connected with said motor and fixedly connected with a lower end portion of said at least one backward link element which corresponds to said lower pivotal support point of the at least one backward link element, wherein, upon operation of said motor, said driving shaft is rotated causing said at least one backward link element to rotate in said forward direction, causing simultaneous forward rotation of said at least one forward link element, thereby inclining and displacing said folded state of said basic seat unit in said forward direction from the substantially horizontal state, down to the lower storage position, so that, at said particular lower storage position, said folded state of said basic seat unit is set in a substantially horizontal state upon said lower floor area, whereas, upon reverse operation of said motor, said driving shaft is subjected to a reverse rotation to thereby cause said at least one backward link element to rotate in said backward direction, causing simultaneous backward rotation of said at least one forward link element, thereby inclining the folded state of the basic seat unit upwardly from the substantially horizontal state and displacing the basic seat unit from the lower storage position in the backward direction up to the upper use position;
- and
- a resilient repulsive element provided to said driving shaft, said resilient repulsive element being workable so as to increase said driving shaft resilient repulsive force in proportion to an amount of said normal rotation of said driving shaft, thereby providing an increasing resilient repulsive force against the normal rotation of the driving shaft, with a correspondingly increased amount of said resilient repulsive force being simultaneously accumulated in said resilient repulsive element, whereby, when said basic seat unit is displaced from said upper use position to said lower storage position, a load being applied from said basic seat unit to a normal torque of said motor caused by said normal operation of the motor is counterbalanced with said increasing resilient repulsive force of said resilient repulsive element, and, conversely, when said basic seat unit is displaced from said lower storage position to said upper use position, a load being applied from said basic seat unit to a reverse torque of said motor caused by said reverse operation of the motor is counterbalanced with said correspondingly increased amount of said resilient repulsive force accumulated in said resilient repulsive element.