WO1992004844A1

WO1992004844A1 - A chair

Info

Publication number: WO1992004844A1
Application number: PCT/AU1991/000412
Authority: WO
Inventors: Karl Schreckenberg
Original assignee: Karl Schreckenberg
Priority date: 1990-09-14
Filing date: 1991-09-05
Publication date: 1992-04-02
Also published as: DE4192338T1

Abstract

A chair comprising a seat (11), a back rest (18) which is pivotally connected to the seat (11), a link (22), a biasing means (27) and a frame support (15), wherein the frame support (15) is pivotally connected to a front section of the seat and is pivotally connected to the back rest (18) through the link (22) and biasing means (27).

Description

A cha i r

The present invention relates to chairs for office use or domestic situations.

Typically, chairs for use in offices consist of a seat which is provided with a back rest which may be adjusted independently of the seat. Other chairs are provided with a seat and back rest which are connected together and are pivotally mounted on a stand.

The present invention provides an alternative chair comprising a seat, a back rest which is pivotally connected to the seat, a link, a biasing means and a frame support, wherein the frame support is pivotally connected to a front section of the seat and is pivotally connected to the back rest through the link and biasing means.

Preferably, the link is pivotally connected to the frame and back rest.

The link may comprise a proximal and distal end such that it is pivotally connected to the frame support at its distal end and is pivotally connected to the back rest at its proximal end. The biasing means may be arranged to oppose relative movement between the back rest and the frame support.

The biasing means may also be arranged to oppose relative movement between the back rest and the frame support when the seat is forced to move towards the frame support.

Preferably, the seat is forced to move towards the frame support when a person is seated on it.

The biasing means may be pivotally connected to the back rest at the same point the back rest is pivotally connected with the seat.

It is preferred that the biasing means be pivotally connected to the frame support at the same point where the link is pivotally connected to the frame support. The link may be pivotally connected to a back rest end of the frame support.

The back rest may be pivotally connected to a back section of the seat. The back rest may comprise a back portion and a linkage portion.

The linkage portion may be pivotally connected to the link. Preferably, the back rest is pivotally connected to the seat between the back and linkage portions.

The biasing means may comprise a gas discharge tube or a spring mechanism.

Preferably, the biasing means is arranged to move the seat back to a steady state position when a force applied to the top of the seat is removed therefrom.

Preferably, the frame support is arranged to be fixed to a stand.

The back rest linkage portion may comprise an upper end portion which is pivotally connected with the link

It is preferred that when the seat is in a steady state, the pivotal connection between the link and the back rest be located above the pivotal connection between the link and the frame support. Preferably, when the seat is in its steady state position, the link is approximately inclined at 45° with respect to a horizontal line drawn parallel with the surface of the seat.

Preferably, downward motion of the seat causes the back rest to move clockwise about its pivotal connection with the seat, which in turn is arranged to move the link clockwise about its pivotal connection with the frame support.

It is preferred that the seat move clockwise about its pivotal connection with the frame support, when a person is seated on the seat.

The biasing means may be pivotally connected to the seat at a point separate from the pivot point at which the back rest is connected to the seat. The frame support preferably, comprises a stan rigidly connected to an arm pivotally connected to the fron section of the seat. A preferred embodiment of the present inventio will now be described by way of example only with reference to the accompanying drawings in which Fig. l shows a side view of a chair according to the present invention and figure 2 shows an adjustment mechanism.

The chair shown in the drawing, comprises a seat 11 which at its front is pivotally connected to a fram support arm 12 through a pivot pin 13.

The frame support arm 12 has a shoulder portio 14 which is arranged to be attached to a stand 15. In the drawing the stand is located on one side of the seat, however, in practice it is envisaged that the stand be of cylindrical configuration and be located approximately centrally below the seat. In one embodiment it is envisaged that the sea be provided with a recess to allow the seat to move relativ to the stand without having the stand impinge upon the lowe surface of the seat.

At the back of the seat 11 a pivot pin 16 is provided through which a back rest 17 is pivotally connecte to the seat 11. The back rest comprises a back portion 18 and a linkage portion 19. In the drawing shown, the back rest has the appearance of a boomerang shape but in practic it may be of any shape. The linkage portion 19 extends towards the stand 15 approximately at 45° with the top surface of the seat 11. At the end of the linkage portion 19 which is closest to the stand 15, an upper portion 20 is provided with a pivot pin 21. A link 22 in the form of a lever having a proximal end 23 and distal end 24 has its distal end pivotally connected to the pivot pin 21 and its proximal end 23 pivotally connected to a lower back portion of the frame support arm, shoulder portion 14, by means of pivot pin 25. The back end 26 of the frame support arm is located adjacent the opposing end of the linkage portion 19 with a sufficient gap therebetween to allow relative motion between the frame support arm 12 and the back rest 17. A gas discharge tube 27 is pivotally connected between pivot pin 16 and pivot pin 25. In figure 1, the sleeve of the gas discharge tube is shown closest to the pivot pin 16. However, this is not a limitation on the way the gas discharge tube may be connected between pivot pin 16 and 25.

Figure 2, shows the manner in which the discharge tube 27 is connected to the pivot pin 25 to provide a means of adjustment of the chair. Pivot pin 25 has a cam surface and is connected with the gas discharge tube 27 by means of pushing 28 which fits over the pivot pin 25.

Arm 27A of the gas discharge tube 27 is located within the end of the bushing 28 and in addition is provided with a tongue 27B at the end nearest the pivot pin 25, which tongue 27B is in contact with the surface of pivot pin 25. The arm 27A of the gas discharge tube is slidable within sleeve portion 28A of the bushing 28 and is normally biased in contact with the surface of pivot pin 25. By turning pivot pin 25 the tongue 27B of the arm of the gas discharge tube 27A, can be made to move towards or away from pivot pin 25. Thus, increasing or decreasing the distance between pivot pins 25 and 16.

When a person is seated on seat 11, a force is applied to the top of seat 11 which tends to move the seat clockwise with respect to the pivot pin 13. This clockwise motion moves the seat 11 down towards the stand 15 which stand is normally stationary.

As the seat 11 moves down, the back rest 17 tends to rotate clockwise about pivot pin 16. This moves the lower end of the linkage portion 19 upwardly so that the link 22 tends to rotate anticlockwise about pivot pin 25. Movement of the link 22 about pivot pin 25 and movement of the back rest 17 about pivot pin 16 is limited by the gas discharge tube 27. When the force applied to the seat 11 is equal to the restraining force applied by the gas discharge tube, the seat 11 will be prevented from any further movement towards the stand 15.

By removing the force applied to the top of seat 11, the gas discharge tube will tend to force the s 11 back to its original position (its steady state position) . In such a situation the back rest 17 will the tend to move clockwise about pivot pin 16 and the link 22 will tend to move clockwise about pivot pin 25.

The overall effect is that by seating a pers on seat 11, the back portion 18 will tend to move away fr the top of the seat 11. When a person removes himself fr the chair, the top of the chair returns to its original position and the back portion 18 moves towards the top of the seat 11 back to its original steady state position. Because of the adjustment mechanism shown in figure 2, it is possible to vary the distance between piv pins 25 and 16 as desired, thus, enabling a person seated seat 11 to move the seat 11 with respect to the back rest so as to achieve a desired configuration. It is preferre that the pivot pin 13, be located as close to the front o the seat 11 as possible so as to enable a persons feet to remain on the ground during any stage of the above descri tilting action of the seat 11 and back rest 17.

In a preferred embodiment of the present invention it is also possible to provide return pressure enable the seat and back rest to resume its original stea state position by providing a gas spring and additional spongy material in the seat.

In an alternative embodiment the pivot pin 2 may be located at a lower end of the linkage portion 19 s that it is located lower than the pivot pin 25 and thus t link 22 slopes downwardly from the pivot pin 25 towards thepivot pin 21. In such a situation movement of the sea 11 downwardly can be arranged to move the back portion 18 towards the top of the seat 11. Thus, the back rest 17 moves counter clockwise and the link 22 moves clockwise.

In an alternative embodiment, a frame suppor arm is provided on either side of seat 11 such that each frame support arm is connected to the stand 15.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A chair comprising a seat, a back rest which pivotally connected to the seat, a link, a biasing means a frame support, wherein the frame support is pivotally connected to a front section of the seat and is pivotall connected to the back rest through the link and biasing means.

2. The chair as claimed in claim 1 wherein the link is pivotally connected to the frame and back rest.

3. A chair according to claim 2 wherein the li comprises a proximal and distal end such that it is pivotally connected to the frame support at its distal e and is pivotally connected to the back rest at its proxi end.

4. A chair according to any one of the precedi claims wherein the biasing means is arranged to oppose relative movement between the back rest and the frame support.

5. A chair according to any one of the precedi claims wherein the biasing means is arranged to oppose relative movement between the back rest and the frame support when the seat is forced to move towards the fram support.

6. A chair according to any one of the precedi claims wherein the seat is forced to move towards the fr support when a person is seated on it.

7. A chair according to any one of the precedi claims wherein the biasing means is pivotally connected the back rest at the same point the back rest is pivotal connected with the seat.

8. A chair according to any one of the precedi claims wherein the biasing means is pivotally connected the frame support at the same point where the link is pivotally connected to the frame support.

9. A chair according to any one of the precedi claims wherein the link is pivotally connected to a back rest end of the frame support.

10. A chair according to any one of the precedi claims wherein the back rest is pivotally connected to a back section of the seat.

11. A chair according to any one of the precedi claims wherein the back rest comprises a back portion an linkage portion.

12. A chair according to claim 11 wherein the linkage portion is pivotally connected to the link.

13. A chair according to claim 12 wherein the b rest is pivotally connected to the seat between the back linkage portions.

14. A chair according to claim 13 wherein the biasing means comprises a gas discharge tube or a spring mechanism.

15. A chair according to claim 14 wherein the biasing means is arranged to move the seat back to a ste state position when a force applied to the top of the se is removed therefrom.

16. A chair according to claim 15 wherein the f support is arranged to be fixed to a stand.

17. A chair according to claim 16 wherein the b rest linkage portion comprises an upper end portion whic pivotally connected with the link.

18. A chair according to claim 17 wherein when seat is in a steady state the pivotal connection between link and the back rest is located above the pivotal connection between the link and the frame support.

19. A chair according to claim 18 wherein when seat is in a steady state position the link is approxima inclined at 45° with respect to a horizontal line drawn parallel with the surface of the seat.

20. A chair according to claim 19 wherein downw motion of the seat causes the backrest to move clockwise about its pivotal connection with the seat, which in tur arranged to move the link clockwise about its pivotal connection with the frame support.

21. A chair according to claim 20 wherein the seat is arranged to move clockwise about its pivotal connection with the frame support when a person is seated on the seat.

22. A chair according to claim 21 wherein the biasing means is pivotally connected to the seat at a point separate from the pivot point at which the back rest is connected to the seat.

23. A chair according to claim 1 wherein the frame support comprises a stand rigidly connected to any arm pivotally connected to the front section of the seat.

24. A chair substantially as hereinbefore described with reference to the accompanying drawings.