Chair

Abstract

A chair includes a support base body portion; a backrest rotatably supported with respect to the support base body portion on an axis in a width direction of the support base body portion and being displaceable from an initial state to an inclined state of being inclined rearward; a biasing member configured to bias the backrest in the inclined state, in a direction of returning to the initial state; an adjuster configured to adjust a biasing force of the biasing member; and an operating member joined to the adjuster and configured to operate the adjuster, wherein the biasing member is provided in the backrest or the support base body portion, the adjuster is provided in the backrest, and the operating member is disposed behind the axis and on one side of the backrest in the width direction.

1 . A chair comprising:
 a support structure;   a backrest rotatably supported with respect to the support structure on an axis in a width direction of the support structure and being displaceable from an initial state to an inclined state of being inclined rearward;   a biasing member configured to bias the backrest in the inclined state, in a direction of returning to the initial state;   an adjuster configured to adjust a biasing force of the biasing member; and   an operating member joined to the adjuster and configured to operate the adjuster, wherein   the biasing member is provided in the backrest or the support structure,   the adjuster is provided in the backrest, and   the operating member is disposed behind the axis and on one side of the backrest in the width direction.   
     
     
         2 . The chair according to  claim 1 , wherein
 the backrest includes two side walls spaced apart from each other in the width direction,   the adjuster is disposed between the two side walls, and   the operating member includes
 an operation shaft extending in the width direction and having an outer end portion in the width direction and an inner portion in the width direction, the outer end portion protruding outward from a space between the two side walls, and the inner portion being joined to the adjuster at a position between the two side walls, and 
 an operation lever provided in the outer end portion of the operation shaft. 
   
     
     
         3 . The chair according to  claim 2 , wherein
 the adjuster is located above the support structure.   
     
     
         4 . The chair according to  claim 1 , wherein
 the adjuster includes an acting member that acts on the biasing member, and a support member that movably supports the acting member, and   the support member is fixed to the backrest.   
     
     
         5 . The chair according to  claim 4 , wherein
 the acting member includes an action shaft that supports the biasing member, and an adjustment shaft that is disposed such that an axis direction thereof is parallel with a front-rear direction when viewed from above and that enables the action shaft to move in the axis direction, and   the action shaft is displaced along the adjustment shaft by operating the operating member.   
     
     
         6 . The chair according to  claim 1 , wherein
 the biasing member includes a spring that biases the backrest in the inclined state, in the direction of returning to the initial state.   
     
     
         7 . The chair according to  claim 6 , wherein
 the spring is a compression coil spring that makes bias in a front-rear direction above the support structure, and   a rear end portion of the compression coil spring is located to be close to the backrest and is joined to the adjuster.   
     
     
         8 . The chair according to  claim 7 , wherein
 a seat-receiving member receiving a seat is supported at an upper portion of the support structure to be slidable in the front-rear direction,   a front end portion of the compression coil spring is fixed to a front portion of the seat-receiving member, and   the seat-receiving member moves rearward to compress the compression coil spring from front, when the backrest is displaced toward the inclined state.