WO1993009701A1

WO1993009701A1 - Convertible chair

Info

Publication number: WO1993009701A1
Application number: PCT/CH1992/000225
Authority: WO
Inventors: Josef Huser; Keesjan Klant
Original assignee: Josef Huser; Keesjan Klant
Priority date: 1991-11-11
Filing date: 1992-11-11
Publication date: 1993-05-27
Also published as: EP0570550A1

Abstract

A person can convert a chair into a chair with knee support without standing up, by swivelling backwards the pair of plates (5) around the axis (7), thus causing the seating surface (1), which is also secured to the lever (6) to move backwards. At the same time the knee support (2) is folded up forward. The back (3) is lowered and is brought into the correct inclined position by the lever (13).

Description

Convertible chair

The invention relates to a chair according to the preamble of claim 1.

Problem:

It is well known that sitting on a regular chair is not optimal for the spine and internal organs of the human body.

In this regard, a chair with a forward-sloping seat and a knee part that prevents slipping forward is much better. Such a chair usually does not have a backrest because the upper body and its own muscles remain in the vertical balanced position.

However, this knee chair is used relatively rarely, especially in the office area, because it also has certain disadvantages. Among other things, these consist of the fact that there may be problems with the knee load if you sit on it for a long time. The knee part can also have a disruptive effect if you frequently have to get up from the chair or move around with it.

The advantages of these two types of seats can be put to good use if you alternate between them. The consequence of this is that the disadvantages of the two types of seats hardly come into play anymore, because these are present in the corresponding type of seat, especially when sitting continuously. A change from one position to the other has a very positive effect on the blood circulation, because the areas that are stressed become relaxed and replenished.

A change also has the advantage that the type of seat can be optimally adapted to the corresponding work. The knee chair position can be used for quieter work, e.g. Writing, reading, EDP etc.) and the usual sitting position for more flexible work Cz.B. Classify files, work that requires getting up often, etc.).

Since it is cumbersome to have two chairs at the workplace and to switch between them, it makes sense to combine these two types of seat in one chair, which can be switched from one to the other.

There are various designs in this direction. Some are characterized by the chair being rotated 180 degrees to move to the knee position and the backrest is moved down and used as a knee part.

Such constructions are described in the following patents: WO 91/10384, US Pat. 4,736,982, US Pat. 4, 793, 665 and AT 394 134B. At least one solution is to fold the backrest forward over the seat and use it as a knee support. Such a construction is shown in patent WO 88/04903.

The disadvantage of these solutions is that you have to get up from the chair when changing the chair and partly also the knee part, because it was previously used as a back part when you have to switch to the knee position.

At least one construction is that when moving in the knee position the seat is only tilted forward and two knee supports that are normally under the seat are folded forward. The advantage of this solution is that you do not have to get up to switch. However, the seat in the knee position is very far forward in comparison to the standard knee chairs and therefore very close to the knee parts, ie not optimal. A further forward shifting of the knee parts is hardly possible with this construction if the chair is built on a 5-star base, because otherwise the focus of the person would come too far forward.

Task:

The object of the invention is to propose a convertible chair which does not have any of these disadvantages. This means that the following conditions must be sought:

Changing the chair from the sitting position to the knee position and vice versa: a) takes place while sitting, i.e. without getting up from the chair.

b) takes place in a movement sequence and it is not necessary to readjust an element. Conditions of the chair in sitting position: c) Office chair with 5-star base including gas lift and usual mobility and adjustability.

d) the same legroom as possible as a conventional office chair e) no more space required than a conventional office chair

Conditions of the chair in knee position: f) Knee chair on 5-star base with usual adjustability and mobility.

g) the individual elements must be placed so that they

ergonomically and with regard to the center of gravity of the person with a usual knee chair.

These conditions are met by claim 1, claim 5 fulfilling point d even better.

Fig. 1: chair in sitting position

Fig. 2: Chair in the knee position

Fig. 3: Exploded view of the chair in the sitting position

Fig. 4: Backrest attached to the back of the seat

Fig. 5: Seat part on rail guide

Fig. 6: Knee part on rail guide

Fig. 7: Knee part foldable in the longitudinal axis Moving the chair as described in claim 1 is made possible by the fact that the seat part, the knee part and the backrest are connected to the foot column by a lever construction (for example a castor star base with gas lift height adjustment) as follows:

See Fig. 1, 2 and 3:

Block 4 is fixed with. connected to the foot column. The pair of plates 5, which is firmly connected to one another, is connected to the block 4 by the axis 7. The lever 6 is connected to the axis 9 with this.

The seat part 1 (provided below with a U-shaped arrow) is fastened with the axis 8 to the pair of plates 5 and with the axis 10 to the lever 6.

The backrest 3 is fastened to the pair of plates 5 with the axis 11, the knee part 2 to the axis 14.

In the "sitting" position, the seat part 1 lies against the pair of plates 5. The lever 12, which is firmly connected to the backrest, presses against a stop on the pair of plates 5. The knee part 2 is fastened to the support 17 and is pulled upwards by this with the lever 16 which is connected to the lever 6.

In the "knees" position, the seat 1 moves backwards until it strikes the lever 6. The backrest 3 is moved downwards by the pair of plates 5, being pivoted in with the lever 13 which is fastened to the block 4, the knee part 2 is driven downwards by the lever 16 via support 17 until the bolt 15 reaches a stop on Plate pair 5 is pending. The chair can be moved over by means of a handle attached to the side of the pair of plates 5 by moving it downwards or upwards. Shifting the upper body significantly supports this movement.

The two positions of the chair are fixed by a snap or a lock.

Backrest attached to seat part:

Backrest as described in claim 2

A somewhat simpler construction for attaching the backrest is that it does not move downwards when it is switched over to the knee position, but remains attached to the back of the seat. This solution is conceivable for applications in which the space requirement of the chair is not critical.

See Fig. 4

The backrest 1 is connected to the joint 3 on the seat part 2. In the sitting position, it is pushed forward by the lever 4 and the stop 5, while in the knee position it is pulled by the spring 6 to the stop 7 and thereby moved backwards.

Seat part with rail guide:

Movement of the seat part as described in claim 3

Another way to move the seat is with a rail guide instead of the lever construction.

See Fig. 5 The seat part 1 is firmly connected to the rails 2, which are guided by the rollers 3.

It is fixed in the corresponding position by the lock 4.

It is also possible to guide the seat part only through a rail at the rear and to guide the front part through a lever similar to the pair of plates 5 (Fig. 1-3).

Knee part with rail guide:

Movement of the knee part as described in claim 4

The space under the chair also allows a rail guide to move the knee part.

See Fig. 6:

The knee part 1 is firmly connected to the rails 2, which are guided by the rollers 3.

It is unfolded for the knee position by the rope 4 which is fastened to the seat part 5 and folded in with the spring 6 in the case of Sitzpαsitiαn.

There is also the possibility to fasten the knee part through the support 17 on the plate pair 5 (Fig.1-3) on the axis 14, the lever 16 being omitted, a roller coming into the axis of the bolt 15, which then comes through a Template that is firmly attached to block 4 is guided so that the knee part is moved into the correct position. Foldable knee part:

The knee part disassembled into two parts, is pivoted into Sitzpositiαn as described in claim 5

This construction enables optimal legroom.

The two halves of the knee only take up a few cm of space on each side of the under-seat mechanism, which in turn should only be a few cm wider than the foot column. See Fig. 7:

The two knee parts 2a are firmly connected to the hinge pieces 18. These hinge pieces are pivotally attached to the knee support 17a. In the unfolded state (knee position), the knee parts 2a move into the horizontal position by gravity or supported by springs. When changing over to the sitting position, they are moved upwards by the support 17a, where they are in contact with the pair of plates 2, forward in the middle and therefore laterally folded back on the outer sides.

Claims

Claims: = = = = = = = = = = = = = = = =

1. Chair with backrest, which can be converted into a knee chair, also known as a knee stool, characterized in that the seat, backrest and knee part are connected to one another and to the lower part of the chair by a lever mechanism such that when changing over from the chair to the knee chair in one movement the seat is moved backwards and at the same time is inclined towards vαrne, the knee part, which is at least partially under the seat, is moved to the knee position after vαrne and that the backrest is moved downwards without having to get up from the chair. (Fig.1u.2)

2, backrest to chair as described in claim 1, characterized in that it is not moved downwards, but to the rear, wα it can be used if desired in the knee position as a back support, also characterized in that it is at the back of the seat with a Joint is attached, moves backwards in the knee position by a spring and is held in the correct position in the sitting position by a stop located under the seat. (Fig.4)

3. Seat part to chair as described in claim 1, characterized in that during the changeover process the seat part by a construction consisting of at least one rail which runs in at least one guide or a combination of such a guide and a lever guide to the rear or is moved forward. (Fig.5)

4. knee part to chair as described in claim 1, characterized in that the knee part by a construction consisting of at least one rail that runs in at least one guide or a combination of such a guide and a lever guide and by a chain, rope, band or a lever construction is driven from the seat surface into which two positions are moved. (Fig.7)

5. knee part to chair as described in claim 1, characterized gekennzeichnett that the knee part is provided with at least one joint, or hinge in the longitudinal axis, which makes it possible that in the folded state, the two side parts can be pivoted back against the chair leg. (Fig.6)