Chair, in particular work or office chair

Claim 1

In a chair having a seat that is variable in inclination and is pivotal in a forward region about a horizontal pivot shaft, a backrest, an inclination of which is mandatorily disproportionately variable as a function of a change in inclination of the seat, with increasing inclination of the seat the backrest approaching a rear end of the seat, the horizontal pivot shaft of the seat being limitedly adjustable both downward and toward the backrest on a bearing block of a chair pedestal, the seat being pivotally connected to a plurality of pivot levers, each of said pivot levers comprising three segments, a first segment attached to said backrest, a second segment extending at a right angle to said first segment, an end of said second segment opposite said first segment being pivotally attached to the underside of said seat and spaced apart by about 1/4 of a depth from said rear end of said seat and a third segment adjoining and extending from the pivotally attached opposite end of said second segment, the improvement comprising: the end of said third segment (18) opposite said second segment (19) pivotally attached to said bearing block (10) approximately beneath a middle of said seat (14); said second segment (19) and said third segment (18) forming an obtuse angle of approximately 150° to 170° in a direction facing away from said seat (14), said second segment (19) extending approximately horizontally in an upright position of said chair; said pivot levers (17) joined together in a vicinity of said first segments (20) which carry said backrest (22), and a gas spring (24) pivotally (13, 23) supported on said bearing block (10) and on a cross bar (27) joining said first segments (20); a horizontal bearing block crossbar (26) secured to a front end of said bearing block (10), vertical tabs (15) secured to said seat (14) and having bores for receiving shaft ends of said horizontal pivot shaft (28), said vertical tabs overlapping crossbar ends of said horizontal bearing block crossbar (26), said horizontal pivot shaft (28) adjustable limitedly downward and toward said backrest in at least one oblong slot (11) disposed in at least one of said bearing block (10) and each of said crossbar ends of said horizontal bearing block crossbar (26); and said bearing block (10) inclining upward to an angle of approximately 20° toward said pivot shaft (28) of said seat (14).