Chair control

• US 5,370,445 A
• Filed: 06/10/1993
• Issued: 12/06/1994
• Est. Priority Date: 06/10/1993
• Status: Expired due to Term

• Current Assignee: Knoll Incorporated (Millerknoll Incorporated)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Golynsky, Arkady
• Primary Examiner(s): Dorner, Kenneth J.
• Assistant Examiner(s): Nelson, Jr., Milton
• Application Number:
  US08/075,070
• Time in Patent Office: 544 Days
• Field of Search: 297/285, 297/300-304, 297/325-328
• US Class Current: 297/326
• CPC Class Codes: A47C 3/026 with central column, e.g. rocking office chairs; Tilting chairs
• CPC Class Codes: A47C 7/441 with adjustable elasticity
• CPC Class Codes: A47C 7/443 with coil springs
• CPC Class Codes: A47C 7/444 of torsion type
• CPC Class Codes: H02K 9/24 Protection against failure of cooling arrangements, e.g. due to loss of cooling medium or due to interruption of the circulation of cooling medium

Abstract

Disclosed is knee tilt chair control mechanism for a pedestal base chair having a chair control housing mounted on the pedestal chair base and pivotally supporting a chair seat support member having a cam surface formed along a portion of the bottom surface thereof. A torsion spring is secured to the chair control housing and is adapted to resist the pivotal movement of the chair seat support member. The torsion spring has a lever arm adapted to move along the cam surface during the pivotal movement of the chair seat support member and thereby make a more effective use of the torsion spring and a chair more comfortable to the user.

Claims

1. A chair, comprising:

a base including a chair seat control housing mounted thereon, said housing having a spring support around which is disposed a torsion spring, said torsion spring having a first leg and a second leg fixedly attached to said housing; and

a chair seat including an integrally connected bottom plate having two side plates connected thereto wherein said two side plates are pivotally connected to said chair seat control housing, said bottom plate further having a downwardly extending cam surface;

wherein said first leg of said torsion spring slidably engages said cam surface during pivotal movement of said chair seat.

2. The chair as recited in claim 1, wherein said cam surface is substantially convex in shape.

3. The chair as recited in claim 1, wherein said cam surface is a plane parallel to but spaced from said bottom plate.

4. The chair as recited in claim 1, wherein said cam surface comprises at least one substantially convex portion and at least one substantially concave portion.

5. A chair, comprising:

a base including a chair seat control housing mounted thereon, said housing having a spring support around which is disposed a torsion spring, said torsion spring having a first leg and a second leg, said housing further having a torsion adjusting means to which said second leg is fixedly attached for changing the fixed position of said second leg relative to said first leg; and

a chair seat including an integrally connected bottom plate having two side plates connected thereto wherein said two side plates are pivotally connected to said chair seat control housing, said bottom plate further having a downwardly extending, substantially convex cam surface;

wherein said first leg of said torsion spring slidably engages said cam surface during pivotal movement of said chair seat.