WO2002100214A1

WO2002100214A1 - Armchair with self-adjusting back position

Info

Publication number: WO2002100214A1
Application number: PCT/YU2002/000010
Authority: WO
Inventors: Eric Radmilo
Original assignee: Eric Radmilo
Priority date: 2001-06-08
Filing date: 2002-06-07
Publication date: 2002-12-19
Also published as: ES2244781T3; ATE292918T1; EP1399044B1; DE60203712D1; EP1399044A1; DE60203712T2

Abstract

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.

Description

Armchair with Self-adjusting Back Position

Technical Field

The present invention is related to the field of furniture design and it concerns the furniture with improved construction that enables anatomically correct sitting in various sitting positions (from an upright to near-reclined).

Concretely, the invention is related to a self-adjusting armchair that enables changes in sitting positions.

Technical problem

Here described invention solves the problem of the construction of an armchair that enables various sitting positions (from an upright sitting to near- reclined) without user's intentional activity (such as manual adjustments) except the unconscious moving forward on the seat while leaning backward.

Background art

It is well known that a modern man spends most of his time sitting, so that it is necessary to make sitting more comfortable and anatomically correct.

According to criteria of adjusting to condition of anatomical support, the existing armchairs can be divided in two groups:

1. Armchairs with fixed seat and fixed backrest with specific geometry suitable for only a small group of users. In this type of armchair changes in sitting position doesn't enable anatomically correct back support in every new position, especially in lumbal zone.

2. Armchairs with adjustable seat and backrest that enables various sitting position for different users, but which needs users activity such as manual adjustments of a desired positions, by means of some special mechanical elements (springs, screws etc).

Disclosure of Invention

Here described invention solves the problem of self-adjustment of back support in changing sitting position from an upright to near recline. This self- adjustment means changing the angle of back support into a new position that suits the new sitting position, without user's intentional activity (any manual adjustment or fixing) except spontaneous and unconscious: moving forward on the seat with simultaneous leaning backward on the upper part of the back support for more reclined sitting position. During this activity, a load on the seat diminishes or completely disappears. As a result of this activity, the back rest, attached to both sides of the armchair by elastic cantilever and rigid lever, with its lower part pulls under the user's back, while the upper part moves backward, thus changing the angle of back support in new position. Throughout this change of position, user leans on the entire length of the backrest. This means that the backrest rotates on the horizontal axis in front of its own plane. Diminishing or disappearance of loads on the seat enables this rotation, unlocking the brake of rotation, which is active only when the seat is loaded. To decreasing loads of the seat comes when, with his hands on the armrests, user leans backward on the upper part of the back support and moves forward on the seat. The seat of the armchair is hanged on the both sides of the armchair by elastic element, which is deformed when the seat is loaded, with its upper part pressing the upper part of the rigid lever, obstructing the rotation of the rigid lever (brake) which is attached on the other end to the back support and obstructs it's rotation too. This means that loads on the seat blocks the rotation of the backrest in any position from an upright to near-reclined. A part of the rotation in the rotation axle carries the elastic cantilever fixed into the sides of the armchair with one end and attached to the backrest with the other. This elastic cantilever also returns backrest to the upright position. Reducing the part of rotation in the rotation axle makes the real performance much easier.

When the user moves forward on the seat for a more reclined position, the useful area of the seat is reduced but that does not lessen the comfort of sitting: in a reclined position of the backrest decreases the pressure on the seat but increases the pressure on the backrest.

Brief description of the Drawings

The Invention is described in detail in the following drawings:

Fig. 1 - is a lateral view of the armchair with the backrest in the upright sitting position.

Fig. 2 - is a lateral view of the aπnchair with the backrest in the near-recline sitting position.

Fig. 3 - is a longitudinal cross-sectional view of the side of the armchair with the rotational axle when the elastic element is not deformed and does not block the rotation of the rigid lever. (Close view)

Fig. 4 - is a longitudinal cross-sectional view of the side of the armchair with the rotational axle when the elastic element is deformed and blocks the rotation of the rigid lever and obstructs the rotation of the backrest. (Close view)

Fig. 5 - is an isometric view of the armchair. Detailed description of Invention

Drawings depicts an armchair with self-adjusting backrest in various sitting position, from an upright (Fig. 1) to reclined (Fig. 2). Integral parts of the armchair are: seat 1, back 2, sides 3 and 4 which are armrests, elements 5 and 6 for joining the sides and tightening the armchair. On both sides are installed constructional elements symmetrically, that ensures the realisation of invention, joining the sides 3 and 4, seat 1 and backrest 2, elastic element 7 which is attached with one of its ends 8 to the side 3 of the chair and to the back part of the seat with the other 9 (this element 7 passes over the rigid lever and is deformed when the seat is loaded, blocking the rigid lever and its rotation on the rotational axle 15), elastic cantilever 10 fixed on one end 11 between the side 3 of the armchair and elastic element 7 and on the other end 12 attached to the backrest 2 and returns the backrest in the upright position, rigid lever 13 with drum-like end 14 fixed on the axle 15 on which the lever 13 rotates and with the other end 16 attached to the back rest 2, the axle 15 hanged on a side 3 of the armchair, on which the rigid lever 13 rotates.

, Shift of the back rest 2 angle starts when user lifting and moving forward on the seat 1 leaves the rear part unloaded, pushing the upper part of the back rest 2 with his shoulders. Back rest 2 which is attached on both sides 12 (its approx. centre of gravity) to the elastic cantilever 10, because of loads on its upper part, depressing the elastic cantilever 10 rotates on the axle 15 because unloaded seat 1 doesn't deform the elastic element 7 that does not push the drum-like end 14 of the rigid lever 13 so it can rotate on the axle 15. This means that unblocked backrest 2 changes its angle in relation to the seat plane 1 moves forward on a path drawn by one end of the rigid lever 16 and the upper edge of the back rest moves back and down.

Loads on the seat 1 stops the rotation of the backrest and stretches the elastic element 7 which is passing over the drum-like end 14 of the rigid lever 13, and by pressure obstructs its rotation on axle 15, this means that by blocking the rotation of the rigid lever 13 the other end of it is still 16. Attached at this point lower part of the backrest is also immobile thereof the backrest rotation is blocked in any of the intermediate positions between an upright to a near recline.

When user lifts from the armchair, he is not pressing the seat 1, elastic element 7 does not pressing the rigid lever 13, it can rotate, elastic cantilever 10 returns to its starting position returning the back rest to the upright position.

Self-adjusting armchair can be made of various flexible materials (e.g. plywood, metal, artificial).

Here described variant represents the rocking armchair type resulting from construction of the sides. The other possible variant is construction with stiff sides of armchair. These two variants do not change the essence of invention.

Specialists in this field know that small modification in form and elements of the armchair also does not change the essence of invention.

Claims

Armchair with Self-adjusting Back Position Claims

1. Armchair with self-adjusting back position wherein the said armchair is characterised in that the rear part of the seat 1 hanged on a side of the armchair 3 by the elastic element 7, that the backrest 2 rotates in relation to the side of the armchair 3 on the axle 15, and that loading of the seat 1 deforms the elastic element 7 that presses the drum-like part 14 of the stiff lever 13, which functions as a brake, blocks the rigid lever 13 and its rotating on the axle 15, which blocks the rotating of the backrest on the axle 15.

2. Armchair according to claim 1, wherein the said armchair is characterised in that the back rest 2 joined with the side of armchair 3 by elastic cantilever 10, in that way the part of the rotation in the axle ]5, resulting from the loads on the backrest 2 is compensate by deformation of elastic cantilever 10.