Ergonomic chair

Abstract

A chair of the tilting type which includes a base, a seat and back, with the base pivotally supporting the seat with two parallel links of a four-bar parallel linkage, with one of the links extending to support the back. The four-bar linkage is duplicated on each side of the chair by forming the two opposite parallel links or cranks from the upturned ends of the tubes which pass through the base in parallel but vertically offset fashion, the base thus forming the fixed bar of the linkage with its opposite bar or coupler being formed by the seat. A spring within the base is operative on one (of both) of the tubes to urge the chair to an upright position. The tubes are pivotally connected to the seat and one of the tubes extends and is fixedly connected to the back. As the back tilts, the four-bar mechanism is engaged and lifts the seat which thereby uses the occupant's weight to counteract the reclining. Also disclosed is an adjustable armrest that can readily raised, or lowered, and optionally rotated in a horizontal plane. A further aspect of the present disclosure is a headrest that is pushed into place when the chair is reclined and retracted when the chair returns to an upright position.

1 . A chair comprising: 
 a) a chair pedestal;    b) a base mounted on said chair pedestal;    c) a back pivotally attached to said base on two sides;    d) said back including an extension attached to each of said base pivot points to lift a rear part of a seat upon the rearward recline of said back;    e) a pair of front legs pivotally attached to each side of said base; and    f) said seat pivotally attached to said front legs    wherein said chair back reclines about a pivot axis substantially co-extensive with the chair occupant's hip joint.