Link mechanism for a chair and a chair

• US 8,029,061 B2
• Filed: 09/30/2010
• Issued: 10/04/2011
• Est. Priority Date: 10/07/2008
• Status: Active Grant

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Fukai, Zenroh
• Primary Examiner(s): BARFIELD, ANTHONY DERRELL
• Application Number:
  US12/923,642
• Publication Number:
  US 20110031794A1
• Time in Patent Office: 369 Days
• Field of Search: 297/320, 297/321
• US Class Current: 297/320
• CPC Class Codes: A47C 1/032 the parts being movably-coupled seat and back-rest A47C1/035 takes precedence
• CPC Class Codes: A47C 1/03238 by means of peg-and-notch or pawl-and-ratchet mechanism
• CPC Class Codes: A47C 1/03261 characterised by elastic means
• CPC Class Codes: A47C 1/03272 with coil springs
• CPC Class Codes: A47C 1/03274 of torsion type
• CPC Class Codes: Y10T 74/20 Control lever and linkage systems

Abstract

There is provided a link mechanism for a chair that is a link mechanism that is used at a chair, the link mechanism for a chair having: a first link whose one end is connected to a bottom surface of a link that supports a seat surface portion of the chair; a second link whose one end is connected to another end of the first link; a first joint portion rotatably connecting the first link and the second link; a second joint portion provided at another end of the second link; and a first elastic resistance unit imparting elasticity in a rotating direction to the second joint portion.

Claims

1. A chair comprising:

a seat surface portion;

a back surface portion;

a first link supporting the seat surface portion;

a second link supporting the back surface portion;

a third link having one end connected to the second link;

a fourth link connected to another end of the third link;

a first joint portion rotatably connecting the third link and the fourth link;

a second joint portion rotatably connecting the first link and the fourth link;

a third joint portion rotatably connecting the third link and the second link;

a first elastic resistance unit imparting repulsion elasticity to the third link;

a second elastic resistance unit imparting elasticity in a rotating direction to the second joint portion; and

a fourth joint portion rotatably connecting the first link and the second link.

2. The chair of claim 1, further comprising:

a fifth link having one end connected to the first link, and having another end connected to the second link;

wherein the fourth joint portion rotatably connects the first link and the fifth link, and

wherein the first link and the fifth link are structured such that the fourth joint portion is disposed at a position that is apart and forward from the second link by a predetermined distance.

3. The chair of claim 1, further comprising, in addition to the second elastic resistance unit, a third elastic resistance unit that imparts elasticity in a rotating direction to the first joint portion.

4. The chair of claim 3, further comprising a first viscous resistance unit imparting viscous resistance to the first joint portion.

5. The chair of claim 1, further comprising a second viscous resistance unit imparting viscous resistance to the third link.

6. The chair of claim 1, further comprising a third viscous resistance unit imparting viscous resistance to the second joint portion.

7. A chair, comprising:

a seat surface portion;

a back surface portion;

a first link supporting the seat surface portion;

a second link supporting the back surface portion;

a third link having one end connected to the second link;

a fourth link connected to another end of the third link;

a first joint portion rotatably connecting the third link and the fourth link;

a second joint portion rotatably connecting the first link and the fourth link;

a third joint portion rotatably connecting the third link and the second link;

a first elastic resistance unit imparting repulsion elasticity to the third link;

a second elastic resistance unit imparting elasticity in a rotating direction to the first joint portion; and

a fourth joint portion rotatably connecting the first link and the second link.

8. The chair of claim 7, further comprising:

a fifth link having one end connected to the first link, and having another end connected to the second link;

wherein the fourth joint portion rotatably connects the first link and the fifth link, and

wherein the first link and the fifth link are structured such that the fourth joint portion is disposed at a position that is apart and forward from the second link by a predetermined distance.

9. The chair of claim 7, further comprising, in addition to the second elastic resistance unit, a third elastic resistance unit that imparts elasticity in a rotating direction to the second joint portion.

10. The chair of claim 9, further comprising a first viscous resistance unit imparting viscous resistance to the second joint portion.

11. The chair of claim 7, further comprising a second viscous resistance unit imparting viscous resistance to the third link.

12. The chair of claim 7, further comprising a third viscous resistance unit imparting viscous resistance to the first joint portion.