| 摘要 |
The present invention solves the problem of self-adjustment of backrest in different sitting positions (from an upright to near reclined). This self-adjustment means positioning of the backrest in new sitting position without users intentional activity (additional adjusting, manual fixing) except for spontaneous and natural: moving forward on the seat with simultaneous leaning on the upper part of backrest in order to stretch out for a more reclined sitting position. On that occasion diminishes or completely disappears loads on the rear part of seat, so there is no force that deforms the elastic element by which the rear part of the seat hangs on the sides of the armchair (it returns to a starting position), elastic element in the backrest rotational axle unlocks the rotation of the rigid lever which release the backrest, that rotates in a new angle in relation to the seat plane, resulting in a new sitting position. When the backrest comes to the new position, the user sits again on the seat, force that appears in elastic element deforms it, by which its upper part is pressing the rigid lever blocking its rotation and blocks the rotation of the backrest that is attached to the other end of rigid lever. Elastic cantilever attached on both sides of the backrest returns it from any position to the upright position, when there is no loads on the seat to block the rotating of the backrest. This elastic cantilever also reduces the braking in the rotational axle. |
