Folding and positioning device for tier-seats

Abstract

A folding and positioning device for tier-seats comprising several linked seats 1 in the same row with their pedestals 3 . At least one rotational leg 2 is fixed in the middle on the rotational shaft 7 on the upper front side inside the pedestal, its upper end fixed on the seat 1 and the lower end having a step. In the lower rear inside the pedestal is another rotational shaft 5 , on which is fixed a bracketing arm 6 in the position corresponding to the rotational leg 2 . When the seats are being erected to their upright position, the free end of the bracketing arm 6 abuts against the step at the lower part of the rotational leg 2 . Compared with conventional technologies, the present invention calls for very little force in order to erect or lay down the seats. Furthermore, the seats in the entire row are linked joint motion, thus greatly enhancing the efficiency.

What is claimed is:  
     
         1 . A folding and positioning device for tier-seats comprising several seats ( 1 ) with their pedestals ( 3 ) mounted in the same row, characterizing in that the respective seat ( 1 ) are linked up as a whole and there is at least one rotational leg ( 2 ), which is fixed in the middle on a rotating shaft ( 7 ) located at the front upper part of the interior of the pedestal, the upper end of the rotational leg is fixed on the seat ( 1 ) and a step is provided on its lower end, another rotating shaft ( 5 ) is provided at the lower rear part in the pedestal, on which a bracketing arm ( 6 ) is fixed in the position corresponding to the rotational leg ( 2 ), when the seats are in an unfolded and positioned state, the free end of the bracketing arm ( 6 ) abuts against the step at the lower end of the rotational leg ( 2 ).  
     
     
         2 . A folding and positioning device for tier-seats according to    claim 1   , characterizing in that an adjusting bolt ( 4 ) is provided at the upper end of said pedestal ( 3 ) and when the seats are unfolded and positioned, the outer extending end of the bolt ( 4 ) just abuts against the back of the rotational leg ( 2 ).  
     
     
         3 . A folding and positioning device for tier-seats according to    claim 1   , characterizing in that a gravity balance torsion spring ( 71 ) is mounted on the rotational shaft ( 7 ) in the middle of said rotational leg ( 2 ), one end of the torsion spring ( 71 ) is secured to the rotational leg ( 2 ), and the other end is secured to the fixed bracket ( 31 ) in the corresponding position on the pedestal ( 3 ).  
     
     
         4 . A folding and positioning device for tier-seats according to    claim 1    or    2    or  3 , characterizing in that the respective seat ( 1 ) is linked up together by a transverse tube ( 12 ) that runs through the middle part of a legs ( 11 ) of the seat.  
     
     
         5 . A folding and positioning device for tier-seats according to    claim 4   , characterizing in that the upper end of said rotational leg ( 2 ) penetrates said transverse tube ( 12 ).  
     
     
         6 . A folding and positioning device for tier-seats according to    claim 1    or    2    or  3 , characterizing in that on the rotational shaft ( 5 ) there is at least one torsion spring ( 51 ) which maintains the free end of the bracketing arm ( 6 ) in its horizontal or vertical positions, said torsion spring ( 51 ) is fixed to the rotational shaft ( 5 ) at one end and to one of the fixed brackets ( 31 ) inside the pedestal  3  at the other end.  
     
     
         7 . A folding and positioning device for tier-seats according to    claim 5   , characterizing in that on the rotational shaft ( 5 ) there is at least one torsion spring ( 51 ) which maintains the free end of the bracketing arm ( 6 ) in its horizontal or vertical positions, said torsion spring ( 51 ) is fixed to the rotational shaft ( 5 ) at one end and to one of the fixed brackets ( 31 ) inside the pedestal  3  at the other end.  
     
     
         8 . A folding and positioning device for tier-seats according to    claim 1    or    2    or  3 , characterizing in that at least one stepping arm ( 8 ) is connected to said rotational shaft ( 5 ).  
     
     
         9 . A folding and positioning device for tier-seats according to    claim 8   , characterizing in that said stepping arm ( 8 ) has a circular bushing sheathing the rotational shaft ( 5 ), said circular bushing having an arc-shaped nick, a side cam of a transmission bushing ( 52 ) which sheathes the rotational shaft ( 5 ) and is fixed thereupon is located just in the arc-shaped nick and keeps a clearance in it.  
     
     
         10 . A folding and positioning device for tier-seats according to    claim 9   , characterizing in that the free end of the stepping arm ( 8 ) is hinged on a footplate ( 81 ), which covers a gap in the pedestal ( 3 ).