RS20090017A - Combined self adjusting backrest - Google Patents

Abstract

Invention herewith described refers to the combined self adjusting backrest that by changing the inclination in relation to the seat (S) plane provides for the user anatomically correct rests in an upright sitting position s well as in a backward-inclined sitting position. The backrest (1) consists of three functional and structural zones: the upper part of the backrest (1) which is anatomically profiled (including support for the lumbar spine and above it) and connected with the backrest holders (4) through the zone (2) of inclination. Holders (4) of the backrest are with the lower end console mounted to the seat (S) or the chair structure and immovable.In an upright sitting position, the user’s shoulder pressure on the top of the backrest (1) is minimal and it will be minimally inclined backwards around a horizontal axis (3) at the height of lumbar bending in the zone (2) of inclination. When the user moves forward in the seat (S) to change the seating position, the shoulder increases the pressure on the upper part of the backrest (1) and it will significantly incline backwards. Since the lumbar support always maintains the same position, in this position of the upper part of the backrest (1) (changed inclination) the user is also provided with the supports for the backrest and the lumbar spine zone and above it.