Tiltable chair

• US 5,195,801 A
• Filed: 10/24/1991
• Issued: 03/23/1993
• Est. Priority Date: 01/05/1989
• Status: Expired due to Fees

• Current Assignee: Wilkhahn Wilkening & Hahne GmbH & Co. KG.
• Original Assignee: Wilkhahn Wilkening & Hahne GmbH & Co. KG.
• Inventors: Franck, Klaus, Sauer, Werner
• Primary Examiner(s): Chen, Jose V.
• Application Number:
  US07/782,898
• Time in Patent Office: 516 Days
• Field of Search: 297/300-304, 297/316
• US Class Current: 297/300.5
• CPC Class Codes: A47C 1/03255 with a central column, e.g. rocking office chairs
• CPC Class Codes: A47C 1/03272 with coil springs
• CPC Class Codes: A47C 1/03277 with bar or leaf springs
• CPC Class Codes: A47C 1/03288 with resilient blocks

Abstract

A tiltable chair in which a back rest is supported by at least one rear lever via a swivel joint and the seat is supported by a resilient, flexible front mounting element on a pedestal in such a way that when the back rest is tilted forwards or backwards the seat simultaneously partakes of an approximately horizontal, linear movement and the rear part of the seat partakes of a greater lifting or lowering movement than the front part of the seat.

Claims

1. A chair construction comprising a pedestal member;

a seat member having a forward end and a rearward end;

a back rest having an upper end and a lower end;

means connecting said back rest to said pedestal member for rocking movements of said back rest about a substantially horizontal first axis;

means coupling said seat member to said back rest; and

flexible and resilient mounting means connecting said seat member to said pedestal member, the flexibility of said mounting means enabling said mounting means to deform from an unstressed condition an amount sufficient to enable said seat member simultaneously to rock about a second substantially horizontal axis and move endwise between forwardmost and rearwardmost positions in response to said rocking movements of said back rest about said first axis, the resilience of said mounting means constantly biasing said mounting means toward said unstressed condition.

2. The construction according to claim 1 wherein said mounting means comprises a springy member fixed at one end to one of said members and pivoted at its opposite end to the other of said members.

3. The construction according to claim 2 wherein said one of said members is said pedestal member.

4. The construction according to claim 2 wherein said springy member comprises a spiral tension spring.

5. The construction according to claim 2 wherein said springy member comprises a buffer formed of rubbery material.

6. The construction according to claim 2 wherein said springy member comprises a leaf spring.

7. The construction according to claim 1 wherein the means coupling said seat member to said back rest is pivotal.

8. The construction according to claim 1 wherein the means coupling said seat member to said back rest comprises a flexible member joined to said seat member at its rearward end and to said back rest at its lower end.

9. The construction according to claim 1 wherein the means connecting said back rest to said pedestal member comprises a lever pivoted at one end to said pedestal member and joined at its opposite end to said back rest, and wherein the means coupling said seat member to said back rest comprises a swivel joint connecting said seat member to said lever at a point between its ends.

10. The construction according to claim 9 wherein the distance between said point and said first axis is between 1.5 and 2.5 times the distance between the connection of said lever to said pedestal member and the connection of said mounting means to said pedestal member.

11. The construction according to claim 9 wherein the distance between said point and said first axis is about 2 times the distance between the connection of said lever to said pedestal member and the connection of said mounting means to said pedestal member.

12. The construction according to claim 9 wherein said lever is joined to said seat member at the rearward end thereof.

13. The construction according to claim 9 wherein the distance between said point and said first axis is between 1.2 and 1.8 times the distance between the connection of said lever to said pedestal member and the connection of said mounting means to said pedestal member.

14. The construction according to claim 9 wherein the distance between said point and said first axis is about 1.4 times the distance between the connection of said lever to said pedestal member and the connection of said mounting means to said pedestal member.

15. The construction according to claim 9 wherein the rearward end of said seat extends rearwardly beyond said point.

16. The construction according to claim 9 wherein the position of the lower end of said back rest varies in response to rocking movements of said back rest about said first axis.

17. The construction according to claim 16 wherein the lower end of said back rest is at all times above the level of the rearward end of said seat member and wherein the distance between the lower end of said back rest and the rearward end of said seat member is minimum when said back rest has been rocked to its maximum rearward position.

18. The construction according to claim 9 wherein the connections between said seat member and said back rest to said pedestal member define a plane forming an angle of between about 15°

and 40°

to the vertical.

19. The construction according to claim 18 wherein said angle varies in response to rocking of said back rest about said first axis.

20. The construction according to claim 9 wherein the connections between said seat member and said back rest to said pedestal member define a plane forming an angle of between about 40°

and 70°

to the vertical.

21. The construction according to claim 1 wherein said mounting means yieldably biases said seat member to a neutral position between its rearmost and forwardmost positions of adjustment.