| 摘要 |
PURPOSE:To enable a seat cushion to perform movements of three types, in which some one among para-parallel lifting, forward inclination and backward inclination is main, by providing bell cranks, which are pivot suspended both in front and the rear of a base frame, on a lifting operation shaft for a cushion frame. CONSTITUTION:Both in front and in the rear of a base frame 3 are pivot suspended a pair of bell cranks 8, 9 so that they may be free to perform an oscillation motion, and then, the oscillating end 20 of one bell crank is caused to keep in liaison with a cushion frame 5. In addition, a connecting rod 14 is provided along the lower part of the cushion frame 5, of which one end is caused to keep in liaison with a crank pin 13 provided on a lifting operation shaft 10, and the other end with the bell crank 9. In the constitution mentioned above, when the cushion frame 5 is caused to mainly perform a para-parallel lifting movement, the position of a pivot suspension pin 7 and a connecting pin 24 are shifted downwards. While, when it is caused to perform two types of movements, such as forward inclination and backward inclination, the position of the connecting pin 24 is shifted to the crank pin 13 side.
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