Work Chair

Abstract

An ergonomic work chair for activities requiring a bent-forward posture has the following features: a supporting cylinder which protrudes from a star base, a supporting column, which is mounted in the supporting cylinder such that it can be displaced in a vertical cylinder axis, for a base plate with a seat which is fixed on the base plate, a base arm which is fitted to the supporting column or to the base plate, and a pivoting arm, which is mounted on the base arm such that it can be rotated out of the seat region about a vertical axis, having a chest rest and side arm rests, and a support which has a star rest and is hinge-connected to the base plate via a lever mechanism which has fulcrums such that pressing down on the seat causes the star rest to move in the direction of the chest rest.

1 - 12 . (canceled) 
   
   
       13 . A work chair, comprising a supporting cylinder projecting upward from a star base, a supporting column for a base plate with a seat secured on the base plate, which supporting column is mounted in the supporting cylinder displaceably in a vertical cylinder axis, a base arm, which is fitted to the supporting column or to the base plate, and a swivel arm, which has a chest rest and lateral arm rests and is mounted on the base arm such that it is rotatable out of a region of the seat about a vertical axis, and a bracket, which has a lumbar rest and is articulately attached to the base plate, via a lever mechanism having pivot points, such that pressing down the seat causes the lumbar rest to move in the direction of the chest rest. 
   
   
       14 . The work chair as claimed in  claim 13 , wherein the base arm is detachably fitted to the supporting column or to the base plate. 
   
   
       15 . The work chair as claimed in  claim 13 , wherein the swivel arm is mounted on a tubular hinge secured in the base arm, and a resiliently mounted bolt, in a locked usage setting of the swivel arm, passes through a first bore in the hinge and a locking bore in the swivel arm and can be pressed in counter to a spring force to release the locking. 
   
   
       16 . The work chair as claimed in  15 , wherein the tubular hinge can be radially expanded toward an inner wall of the base arm by means of an expansion device and forms with the base arm a detachable clamping joint. 
   
   
       17 . The work chair as claimed in  claim 13 , wherein the chest rest having a narrow rest part is fitted to the swivel arm such that it can be adjusted in height and pivoted in a seat direction. 
   
   
       18 . The work chair as claimed in  claim 13 , wherein the arm rests are fastened to a radial arm by means of a fixable ball joint, and the radial arm is secured via a swivel joint to a clamping sleeve arranged adjustably on the swivel arm. 
   
   
       19 . The work chair as claimed in  claim 13 , wherein the bracket is fastened to the base plate at a first pivot point rotatably about a horizontal rotation axis, and a second pivot point on the bracket is connected by a spring element to a third pivot point on a sliding ring, which is disposed on the supporting cylinder concentrically to the supporting column and such that it is freely rotatable about the cylinder axis. 
   
   
       20 . The work chair as claimed in  claim 19 , wherein the second pivot point on the bracket is disposed, such that it is adjustable in its position, on a slide guided in a slide rail. 
   
   
       21 . The work chair as claimed in  claim 13 , wherein the seat is mounted via a column in an intermediate cylinder such that it is displaceable in the cylinder axis, the bracket is articulately attached via a second pivot point to an auxiliary bracket fastened to the intermediate cylinder, and a third pivot point on a free end of the bracket is connected by a compression spring element to a first pivot point on the base plate. 
   
   
       22 . The work chair as claimed in  claim 13 , wherein the base plate is fitted to a front side of the seat via a swivel joint on an intermediate bracket and is supported by a spring element, the bracket is articulately attached via a second pivot point on the rear side of the seat to the intermediate bracket, and a third pivot point on the free end of the bracket is connected by a compression spring element to a first pivot point on the base plate. 
   
   
       23 . The work chair as claimed in  claim 13 , wherein the lumbar rest is bridged by a second lumbar rest particularly enclosing it and can be moved through this. 
   
   
       24 . The work chair as claimed in  claim 13 , wherein the base arm has a first base arm part and a second base arm part projecting vertically upward from this and supporting the swivel arm, and the first base arm part is divided into a fixed first part and a rotatable second part, wherein the two parts can be drawn apart at a step-shaped dividing point by means of an adjusting lever and, following rotation of the second part, can be fixed at a preselected tilt setting of the second base arm part.