Chair

Abstract

A chair is equipped with a leg column 1 , a seat 3 , and a back support 4 . An intermediate supporting member 9 is fitted to an upper end of the leg column 1 , the seat 3 and a back frame 5 are fitted to the intermediate supporting member 9 , and the back support 4 is fitted to an upper end of the back frame 5 via a joint unit 11 . The seat 3 has an elongated shape when viewed from the top, and is fitted to the intermediate supporting member 9 to swivel horizontally. The back support 4 can be turned freely around a first axis 13 and also can be turned freely around a second axis 12 . Since the seat 3 and the back support 4 can be changed into various modes, a using mode of the chair can be changed variously.

1 : A chair comprising: 
 a seat on which a person sits;    an almost plate-like back support having a supporting surface against which a seated person is able to lean a back; and    a back frame to which the back support is fitted via a portion that is different from the supporting surface;    wherein the back support is fitted to the back frame in a condition that at least one motion out of a first motion by which the back support is turned around an axis that extends in a direction to pass through the supporting surface and a second motion by which the back support is turned from a fallen position in which the supporting surface is directed forward to a horizontal position in which the supporting surface is directed just upward is allowed.    
   
   
       2 : The chair according to  claim 1 , where the back support is formed into a long and narrow shape that has a lengthwise direction and a widthwise direction when viewed from a direction facing to the supporting surface, and the first motion is given to the back support by fitting the back support to the back frame such that the back support is turned around a fist axis that passes through an almost center portion in the lengthwise direction and the widthwise direction.  
   
   
       3 : The chair according to  claim 1 , where a rotary bearing that permits the back support to make the second motion is fitted to an upper end portion of the back frame such that the back support is turned freely from an almost forward posture to an upward posture when viewed from a side, and the back support is fitted to the rotary bearing to turn around an axis that extends in a direction to pass through the supporting surface of the back support and extends in a direction to intersect orthogonally with a rotating axis of a joint.  
   
   
       4 : The chair according to  claim 1 , where the seat is formed into a long and narrow shape that has the lengthwise direction and the widthwise direction when viewed from a top, and the seat is supported by legs to swivel horizontally around an almost center portion in the lengthwise direction and the widthwise direction.  
   
   
       5 : The chair according to  claim 1 , where the back frame is supported by a leg column to turn horizontally, and a swiveling center of the back frame coincides with a center of the leg column, and 
 the seat is supported by the leg to swivel horizontally around a position that is deviated from a swiveling center of the back frame in a horizontal direction.    
   
   
       6 : The chair according to  claim 5 , further comprising: 
 an intermediate supporting member provided to an upper end of the leg column to swivel horizontally;    where the back frame is fixed to the intermediate supporting member and also the seat is fitted to a portion, which is deviated from the leg column to an outside when viewed from the top, of the intermediate supporting member to swivel horizontally.    
   
   
       7 : A chair according to  claim 2 , where a planar shape of the seat and an outer shape of the supporting surface of the back support are formed into a bottle gourd shape, a middle portion of which in the lengthwise direction is formed to constitute a narrow portion having a narrowest width and an incomplete circular portion is connected to both sides of the narrow portion, respectively.  
   
   
       8 : The chair according to  claim 3 , where a planar shape of the seat and an outer shape of the supporting surface of the back support are formed into a bottle gourd shape, a middle portion of which in the lengthwise direction is formed to constitute a narrow portion having a narrowest width and an incomplete circular portion is connected to both sides of the narrow portion, respectively.  
   
   
       9 : The chair according to  claim 4 , where a planar shape of the seat and an outer shape of the supporting surface of the back support are formed into a bottle gourd shape, a middle portion of which in the lengthwise direction is formed to constitute a narrow portion having a narrowest width and an incomplete circular portion is connected to both sides of the narrow portion, respectively.  
   
   
       10 : The chair according to  claim 5 , where a planar shape of the seat and an outer shape of the supporting surface of the back support are formed into a bottle gourd shape, a middle portion of which in the lengthwise direction is formed to constitute a narrow portion having a narrowest width and an incomplete circular portion is connected to both sides of the narrow portion, respectively.