WO2002007567A1

WO2002007567A1 - Arrangement in a chair

Info

Publication number: WO2002007567A1
Application number: PCT/NO2001/000315
Authority: WO
Inventors: Hans Chr. Mengshoel; Oddvin Rykken; Ness Thomas; Nils Erik Skeide
Original assignee: Balans Management As
Priority date: 2000-07-21
Filing date: 2001-07-20
Publication date: 2002-01-31
Also published as: NO20003763L; NO20003763D0; NO312876B1; AU2001280276A1

Abstract

The invention relates to a chair, in particular an office chair, with a saddle like seat. The seat is made from a flexible material, allowing the curvature of the seat to be varied to suit the chosen elevation of the seat. The chair includes a mechanism for adjusting the said curvature. The adjustment can be made manual or automatic; by in which the instant curvature will be proportional to the elevation.

Description

ARRANGEMENT IN A CHAIR

Field of the invention

The present invention relates to an arrangement in a chair, and in particular a work chair for use in offices and workshops .

Technical background

People sitting in a traditional chair will get a hip angle • (the angle between torso and legs) of 90° or even less. In particular during work this will lead to a sitting position with curved back and the belly being pressed upward against the diaphragm hindering normal breathing.

In recent years, designers of chairs has found it beneficially to alter peoples sitting position into a more elevated position where the hip angle exceeds 90°. This leads to a more active upright position, halfway standing - half sitting, with a balanced upper body and full freedom of breath.

People with intellectual demanding work, like persons working at computers, will in particular benefit from a such position, as the eased breathing leads to a higher oxygen content in the blood and improve the concentration.

Also during many manual work operations, like working at a bench wise, there might be of benefit to regulate the chair into a higher position than normally to get the necessary force. The alternatives are to stand up or use a normal chair, possibly equipped with a foot ring a short distance above the stand. The standing position is of course tiring in the long run; the support from a chair is needed. If a normal height adjustable work chair is set into a high position, this will result in the forward edge of the seat pressing towards the back of the thighs obstructing the blood flow. A chair with a foot ring will again lead to a sitting position with curved back and the belly being pressed upward against the diaphragm hindering normal breathing .

One prior art solution of the above mentioned problems is to use a forward dipping seat. The original Balans® chair designed by the present applicant, has a forward dipping seat and is equipped with a calf support. After the introduction of the Balans® chair, several other office chairs has been provided with a such seat, or a seat that can be dipped forward, however, without the calf support. This leads to the user slowly sliding forward on the seat. To counteract this movement, the user tightens his/hers leg muscles, and in the event this sitting position becomes painful .

Another modern alternative is to provide a chair in which the seat has a saddle like form. The present applicant markets a such work chair, Balans® 7.40. In this construction the forward corners of the seat are curved downward, and they will therefore not press against the back of the users thighs. Already at a normal, low sitting position this chair offers definite advantages. However, even here the problem of obstructed blood flow will return if the seat is elevated above a certain level. In this way the chair has an optimal operation range, greater than a normal office chair, but nevertheless limited in range. Of this reason Balans® offers a series of seats to its chairs with various degree of curvature, and thus adapted to different ranges of sitting height. Each seat has an optimal sitting height, but will function in a range around this height.

Summary of the invention

The present invention has as its first object to provide a chair which permits a more healthy sitting position, which allows an elevated, if necessary almost standing, work position, the user having a proper balance in the upper body with full freedom to breathe.

Another object of the present invention to provide a chair in which the sitting height can be varied over a relatively great range, while obstructions of blood circulation are avoided at all sitting heights. Preferable, the sitting height should be variable from a normal low height into a next to standing position.

The advantage of the inventive chair, is that the user will experience an improved concentration, due to the higher oxygen content in the blood.

These object is achieved in a chair as defined in the appended patent claims .

Brief description of the drawings

The invention will now be described in relation to the appended drawings, in which:

Fig. la shows the design Balans® 7.40 which currently is produced by the applicant.

Fig. lb shows a detail of the seat from Fig. la.

Fig. 2 shows the various seats that can be deliverd with the Balans® 7.40 chair.

Fig. 3 shows a first embodiment of the new seat, with its regulating mechanism

Fig. 4 shows another regulating mechanism for the seat

Fig. 5 shows still another regulating mechanism Fig. 6 shows still another regulating mechanism

Fig. 7 is a sketch showing a possible embodiment of a chair having automatic regulation of the seat

Fig. 8 shows another embodiment of the automatic regulating mechanism

Fig. 9 shows two other embodiments of the automatic regulating mechanism

Fig. 10 shows an embodiment of the chair with automatic regulation of the seat, and with an optional swing mechanism

Fig. 11 shows still another embodiment of the automatic regulation mechanism

Fig. 12 depicts a slightly different embodiment of the chair shown in Fig. 11

Detailed description of the invention

The owner of the present invention markets a chair, Balans® 7.40, shown in Fig. la), with a saddle like seat 1. The chair comprises a floorstand 5 with wheels 6. The chair can of course be delivered without the wheels if desired, and with other types of floorstands . The floorstand 5 includes a gaslift cylinder 4 with cylinder rod or mounting rod 3. The elevation of the seat 1 can be continuously varied by means of the gaslift cylinder 4, as is well known from current office chairs . At the top of the mounting rod 3 there is a mounting bracket 2 holding the saddle like seat 1.

The seat has a central, more or less flat, part 11 and two flaps or wings 12 and 13 which is turned down from the (horizontal) plane of the central part. The angle between the central part and the wings, is here called the seat's angle of curvature, or ^' curvature for short. The hinge line between the flat part 11 and the wings 12, 13 is shown as broken lines 14 and 15. The lines should preferably meet at the front edge of the seat in the point 16. This particular seat with its saddle like form has the effect of lessening the pressure against the back of the thighs of a person sitting on the chair.

As mentioned in the introduction, the seat is delivered in several different forms, with a curvature of 45, 40, 35 and 15 degree, respectively, as shown in Fig. 2. Each curvature is intended for a specific elevation of the chair. An important feature of a such seat, is that the hinge lines' angle with the front edge, , is made proportional to the curvature. This means that the seat becomes narrower and more pointed in form as the curvature increases, Fig. 2. This is a schematic drawing of the seat, showing its principal form. In the real embodiment the seat is given a more rounded form which is comfortable for the user.

The background for the present invention is that the inventor felt a need for a chair in which the curvature of the seat could be adjusted to suit the chosen elevation. This can be achieved by producing the seat from an elastic material like fibreglass or laminated wood, and distributing the elastic properties of the material in a suitable way.

In its simplest form the hinge lines 14, 15 position can be kept fixed, and let the seat flex along said lines . By introducing a regulation mechanism, the degree of curvature can be varied at will .

However, in a preferred embodiment of the seat, the elastic properties of the seat are distributed in such a way the the "yelding zone" resembles a wedge. Then, the angle α will vary with the curvature . Fig. 3 shows a first embodiment of a mechanism for regulating the curvature of the seat. Belo a seat made from a suitable flexible material there is mounted a regulation mechanism 30 in the form of two rails or connection rods 30a and 30b, respectively. The rails are at the one end tied to the seat in points 34 on the flexible part of the seat. The rails are tied together by means of a screw 32 passing trough slots in the rails and fastened to a nut 33. The screw is operated with a wheel 31. Each rail is riffled at the face opposing the other rail, to increase the friction between the rails. To adjust the curvature of the seat, a user has to loosen the screw 32, force the flexible parts of the seat together until the curvature suits the chosen elevation of the seat, and again tighten the screw 32.

Fig. 4 shows a possible embodiment of the regulation mechanism employing wires between the flexible parts of the seat.

Fig. 5 shows an embodiment in which the curvature of the seat is regulated by a mechanism with toothed racks.

Fig. 6 shows a regulation mechanism including a threaded rod 62 fastened to a first flexible part of the seat by a mount 63, a cylinder 61 with threads on the inside, fastened to a second flexible part of the seat by mount 64. The curvature of the seat is adjusted by means of the wheel 65 at the side of the seat. By turning the wheel the rod 62 will become screwed into or out off the cylinder 61. The distance between the mounts or fastening point will thus be changed and the curvature of the seat accordingly.

These first embodiments of the inventive chair all shows saddle seats in which the curvature may be adjusted manually. Preferable the chair should have a self adjusting mechanism, in which the curvature of the seat is automatically regulated as the user changes the elevation of the seat. An embodiment of the chair including a such automatic mechanism is shown in Fig. 7. The flexible wings of the seat are tied to the floorstand by means of connecting rods or stays 70. When the seat is elevated, the wings will be forced down by the stays, as shown in Fig. 7b. To allow a non-linear relationship between seat elevation and seat curvature, the stays includes elastic elements 71. In the figure, these elements are shown as springs; however, they can simply be implemented as stays made of a flexible material, like polypropylene rope. In order not to hamper the swing mechanism of the chair, the stays are fastened to the gaslift cylinder in a swivel mechanism 72.

In the embodiment shown in Fig. 7 there is no linear relationship between the degree of elevation and the degree of curvature, as the geometry of the stays is dependant on the elevation. Fig. 8 shows an embodiment of the automatic regulation mechanism in which each stay passes through a single block 82. This leads to a linear relationship between elevation and curvature, and in addition the regulation mechanism becomes less obtrusive.

Fig. 9 shows the introduction of still another set of blocks, to give another, non-linear, relationship between seat elevation and seat curvature. That is, the curvature of the seat should change slower than the change in seat elevation .

Fig. 10 shows an embodiment of the chair with a more hidden regulation mechanism. The chair includes a floorstand 106, on which is mounted a gaslift cylinder 101, a mounting rod 105 supporting a seat 100 with variable curvature. On said gaslift cylinder 101 there is turnable mounted a adjustment cylinder 102, which is fastened to the wings by solid stays 103, 104. When the seat is lifted by said mounting rod 105, the cylinder 102 and stays 103, 104 will hold or force down the flexible wings of the seat.

Fig. 11 shows a slightly different embodiment, with a telescopic (duplo) gaslift cylinder 111, 112, 113. The relationship between the forces acted upon the central part of the seat and its wings, is determined by the relative area of each piston.

Fig. 12 shows an embodiment of the chair shown in Fig. 8, in which the chair' s swing mechanism is implemented as a gas cylinder turnable mounted in the floorstand. In this way a separate swivel mechanism can be avoided.

Claims

Patent claims

1. Chair including a seat (20) of a saddle like form, in which the seat (20) includes a central part (21), two imaginary hinge lines (24, 25) , which hinge lines goes from a point (26) at the middle of the front edge of said seat and towards the rim of the seat at an angle α with the front of the seat, which hinge lines (24, 25) defines two side wings (22, 23) fastened to said central part in said hinge lines and which are tilting down from the plane of the central part (21) with an angle called the seat's curvature, c h a r a c t e r i z e d i n that the seat (20) is made of a flexible material, in which the flexibility is distributed over the seat's area so that the curvature can be adjusted, and includes a regulation mechanism (30, 40, 50, 60) for adjusting the curvature.

2. Chair according to claim 1, c h a r a c t e r i z e d i n that the angle α is made proportional to the curvature .

3. Chair according to claim 1 or 2, further including a mounting rod, a floorstand, and a height regulation mechanism, c h a r a c t e r i z e d .i n that the regular mechanism includes stays (70) going from each wing to the floorstand, to allow the curvature of the seat to be automatically adjusted when the height of the seat is regulated by means of the height regulation mechanism.

4. Chair according to claim 3, c h a r a c t e r i z e d i n the stays runs from the wings to first- single blocks located at the mounting rod immediately below the seat, and further along the mounting rod down to the floorstand.

5. Chair according to claim 3, c h a r a c t e r i s e d i n the stays are fastened to the mounting rod in a position immediately below the seat, and run from there to second single blocks located at the side parts, back to first single blocks located at the mounting rod and further along the mounting rod down to the floorstand.

6. Chair according to claim 3, c h a r a c t e r i z e d i n each stay are fastened to the mounting rod in a position immediately below the seat, and run to second single block located at the wing and from there to the floorstand.

7. Chair according to clam 3, 4, 5 or 6, c h a r a c t e r i z e d i n that the stays are fastened to the floorstand in a swivel mechanism.

8. Chair according to claim 3, 4, 5 or 6, c h a r a c t e r i z e d i n that the floorstand includes turnable means, the height regulating mechanism is mounted in said turnable means, and said stays are fastened to the floorstand above said turnable means .

9. Chair according to claim 8 or 9, c h a r a c t e r i z e d i n elastic elements installed in said stays .

10. Chair according to claim 8 or 9, c h a r a c t e r i z e d i n that the stays are made from an elastic material .