Chair

The present patent application relates to a chair to provide an ergonomically better sitting position, as the backrest may be adjusted in such a way that any user can achieve optimal support.

Background

It is a well-known fact that most people are sitting more than before, and that an increasing part of the population have back problems. Thus, it is important how we sit, and that the back gets support in the sitting position. To achieve this, it is an advantage that the chair may be adjusted, in order to give optimal support to any person. Besides, different sitting positions may need different levels of support for the upper part of the body and the neck. Many chairs have support in the lumbar region, but no known chairs have a lumbar support being adjustable in relation to the rest of the backrest. In addition, a chair wherein the support for the upper parts and the neck, are adjustable, will unload the back and give an ergonomically better sitting position.

Norwegian patent 165374 concerns a chair wherein the whole backrest or seat is divided into sections which again are divided into smaller parts, and wherein each part is adjustable independently of the other parts. However, the different parts in each section are fastened to the same releasing-mechanism, in such a way that all parts in one section are released when at least one part of the section should be adjusted. German patent 10152560 concerns another chair, where the backrest is divided into sections. However, these cannot be moved individually, and thus the chair may not be adjusted completely. US 2006/0238006 concerns a chair whose purpose is to both prevent and heal injuries in the back, by fastening the user with belts and foot rests, in the stereotype "correct" sitting position. The backrest of the chair is divided into segments that can only be adjusted one at a time, and this must be done by hand power.

Object The object of the present invention is to present a chair which easily may be adjusted and adjusted according to a person sitting in the chair, in such a way that optimal support for the whole back and the head may be achieved.

The invention The object of the invention is achieved with a chair according to the characterizing part of patent claim 1 or 2.

A chair according to the present invention comprises a seat and a chassis shaped according to known techniques. The horizontal distance between the seat and the backrest, and the height of the seat should be adjustable in order to achieve maximum support to the person sitting in the chair (hereinafter referred to as the user). These features are no part of the invention and may be performed in any known way, which will be obvious to a person skilled in the art.

The backrest of a chair according to the present invention is divided into a number of preferably separate, horizontal sections, wherein each section has its own bearing and adjustment system. Each section may be adjusted individually in relation to the other sections. However, the adjustment has one limitation in that one section can not be adjusted further forward than the sections below. By "further forward" it is in this context, meant closer to the person sitting in the chair, and according to whose back the chair is adjusted. Each section comprises a soft material, preferably a solid foam, offering some support, for instance polyurethane. One surface of the material constitutes a support surface for the person sitting in the chair, and the opposite surface is fastened to a contact piece being a part of the bearing system. The soft material should be thick enough that it feels comfortable for the person sitting in the chair. The section further comprises a stiff sheet between the contact piece of the bearing system and the soft material. This sheet eases the fastening of the section and stiffens it in such a way that it provides better support to the user. The sheet may be flat, but may advantageously have a small curve in such a way that it follows the natural curve of the back. For cleaning and to achieve a more pleasant look, the sheet and the soft material are, in one embodiment, covered with fabric, such as leather or similar. Incidentally, the section preferably has a rectangular shape, where the horizontal distance (width) is larger than the vertical (height). The size of the section may vary, and should be shaped in such a way that it offers a comfortable support for the corresponding back part, but without the user experiencing the section as a hindrance to lateral movement. The number of sections constituting the backrest of the chair, should be between 3 and 9, preferably between 4 and 8, where 5 is optimal. With three sections one will have one section for the upper shoulder, one for the back and one for the lumbar region, with five one gets one for the head and one for the neck, in addition.

The bearing system may be designed in many ways, but it must be fastened to one section at one end, and to the adjustment system at the other end. The system may be designed in such a way that the contact surface between the soft material and the user is further forward in some sections than others, when all sections are in "0" position. By "0" position it is meant that all sections are in their most forward position. In this way it is

possible to achieve a contact point between the user and the soft material that is further forward than the sections below, despite the fact that the section, as such, may not be adjusted further forward.

The adjustment system is connected to a stick or similar, placed under the seat of the chair, in such a way that the user can easily adjust the backrest section. In a preferred embodiment, the system is provided with a stick for each section. The remaining adjustment system may be performed in any known way, which will be obvious for a person skilled of the art.

In an alternative, preferred embodiment, one of the sections is fastened, i.e. not possible to adjust, and the other sections may be adjusted in relation to this. Since the horizontal distance between the seat and the backrest is adjustable, persons of any size may adjust the chair according to their body and achieve optimal support.

In one embodiment of the invention, the whole or parts of the backrest are covered by - an upholstery fabric, and thus, the chair gets a more conventional look. This fabric will only be a fabric and not interfere with the function and/or adjustment of the remaining backrest.

The invention will in the following be illustrated with an example.

Example

In the following there will be described a specially preferred embodiment of the present invention, wherein:

Figure 1 shows the chair from the side, Figure 2 shows the chair at an angle from behind,

Figure 3 shows an enlarged cut from Figure 2, showing the bearing and adjustment system.

Figures 1 and 2 show a chair wherein the backrest is designed according to the present invention. The backrest is divided into five sections 1-5, for supporting the head 1 , neck 2, upper back 3, middle back 4 and the lumbar region 5, respectively. Each section comprises a stiff sheet 17 of which a contact piece 11 of the bearing and adjustment system is fastened to a side surface, and a soft material 6 is fastened to the opposite side face, to optimize the comfort for the user. Four of the sections 1 , 2, 3, 5 may be adjusted individually by activating four sticks 8 on the side of the chair. Section 4 is not adjustable in the shown embodiment, but the other sections may be adjusted in relation to this. The chair also comprises a seat 7, and this may be displaced horizontally in relation to the back (not shown) in such a way that optimal support is achieved.

Figure 3 shows a preferred embodiment of the bearing and adjustment system, to adjust the sections of the backrest. The shown system comprises a couple of parallel transferring

arms 10, connected to each other by a contact piece 11 , and a lockable gas spring 9 for adjusting each section. The system also comprises two bearing axles 12, 13 to which all transferring arms and gas springs should be fastened, respectively. The gas springs 9 are of a type which may be locked and opened anywhere in their movement. The upper parts of the transferring arms in each couple are identical, and have at the least one bendpoint 14, nearby the contact piece 11. The lower parts of the transferring arms are different, as one arm has one additional bendpoint 15, and is rotatably fastened to the upper bearing axle 12, at this bendpoint. The end of the other arm is rotatably fastened directly to the same bearing axle. The end 16 of the first arm, is fastened to one end of the gas spring 9, and the other end of the gas spring is fasted to the lower bearing axle 13. When the user activates the gas spring 9 by means of the stick 8, it will push/pull the end 16 of the transfer arm, and because the arms are rotatably fastened to the upper bearing axle, the supporting piece 11 between the transfer arms 10 will respectively be pushed away/pulled closer to the user. On the upper bearing axle 12, the transfer arms 10 are rotatably fastened in a given order, in such a way that the gas springs 9 are distributed along the whole axle, and further in such a way that the arms 10 ₃ of the closest adjustable section, i.e. section 3 are close to the ends of axle 12, while the arms 1O ₁ of the farthest section, i.e. section 1 , are close to the middle of the axle. The two transferring arms 10 being connected to the same contact piece 11 are fastened in such a way that they are in an equal distance from the ends of the bearing axle. The arms 1O ₅ leading to the section below, i.e. section 5, may be fastened anywhere on axle 12.

Since section 5 is below section 4, which is not adjustable, the gas spring 9 adjusting section 5, must be of the opposite type in relation to the other springs. Preferably, the gas springs are of such a type that when the gas spring is relieved it is expanded maximally, and thus the section is pushed closer to the person sitting in the chair. In order to push section 5 forward when the gas spring is relieved, it must be of opposite type, meaning that this spring must be contracted when it is relieved. Since the transferring arms 10 leading to a section above, must pass behind the sections below, it will be impossible to adjust a section further forward than a section below.

However, the distance from bendpoint 14 to supporting piece 11 may be different for the different sections 1 , 2, 3, 4, 5, and thus the contact point between the soft material and the person sitting in the chair, of section 1 , may be further forward than the contact point of section 3. The bearing system may also be performed with only one transferring arm, instead of two, and this arm may have two bendpoints and otherwise function in the same way as the described system. However, it is advantageously to use two transferring arms because the

section will be more steady. One may also consider other designs of the transferring arms, they may for instance be curved and completely or partly without bendpoint. These will be variations being obvious to a person skilled of the art.

When the user activates a stick 8, the signal will be transferred to the valve of the gas spring by means of a cable (not shown) running in a cable tube under the chair seat 7, to the gas spring 9. The gas spring will be opened in such a way that the user may push the section to the desired position. When the stick is released, the corresponding section will be locked in this position. The section is moved forward to "0" position by opening the gas spring 9 with the stick 8, and then it will push the section forward. In another embodiment gas springs are not used, but rather manual adjustment with corresponding locking means, for instance tracks or grooves and teeth or cotter pins being led into these.

A preferred embodiment of the invention is described above. The different elements may of course be modified and amended, which will be obvious to a person skilled of the art.