Ergonomic chair

• US 6,709,058 B1
• Filed: 06/04/1999
• Issued: 03/23/2004
• Est. Priority Date: 04/09/1999
• Status: Active Grant

• Current Assignee: Humanscale Corporation
• Original Assignee: Humanscale Corporation
• Inventors: Diffrient, Niels
• Primary Examiner(s): BARFIELD, ANTHONY DERRELL
• Application Number:
  US09/326,176
• Time in Patent Office: 1,754 Days
• Field of Search: 297/320, 297/300.1, 297/300.2, 297/300.5, 297/316, 297/319, 297/321
• US Class Current: 297/320
• CPC Class Codes: A47C 1/023 the parts being horizontally-adjustable seats ; Expandable seats or the like, e.g. seats with horizontally adjustable parts
• CPC Class Codes: A47C 1/03 the parts being arm-rests conversion into a bed A47C17/12
• CPC Class Codes: A47C 1/03255 with a central column, e.g. rocking office chairs
• CPC Class Codes: A47C 1/036 the parts including a head-rest
• CPC Class Codes: A47C 31/126 for chairs
• CPC Class Codes: A47C 7/38 for the head adjustable coupled to reclining or easy chairs A47C1/036

Abstract

A chair of the tilting type which includes a base, a seat and back, with the base pivotally supporting the seat with two parallel links of a four-bar parallel linkage, with one of the links extending to support the back. The four-bar linkage is duplicated on each side of the chair by forming the two opposite parallel links or cranks from the upturned ends of the tubes which pass through the base in parallel but vertically offset fashion, the base thus forming the fixed bar of the linkage with its opposite bar or coupler being formed by the seat. A spring within the base is operative on one (of both) of the tubes to urge the chair to an upright position. The tubes are pivotally connected to the seat and one of the tubes extends and is fixedly connected to the back. As the back tilts, the four-bar mechanism is engaged and lifts the seat which thereby uses the occupant'"'"'s weight to counteract the reclining.

Also disclosed is an adjustable armrest that can readily raised, or lowered, and optionally rotated in a horizontal plane.

A further aspect of the present disclosure is a headrest that is pushed into place when the chair is reclined and retracted when the chair returns to an upright position.

Claims

1. A reclining chair comprising:

a) a chair pedestal;

b) a base mounted on said chair pedestal;

c) a seat and a reclining back pivotally mounted to said base;

d) a substantially horizontal rearwardly projecting arm mounted to a member of the group consisting of the chair pedestal, the base and the seat;

e) a track extending in an arcuate path from said back;

f) a carriage movably mounted on said track;

g) a rod connecting said projecting arm and said carriage; and

h) a headrest mounted on the end of said carriage furthest from said seat.

2. The chair of claim 1 further comprising an adjustable armrest.

3. The chair of claim 1 in which said pivotal mounting of said seat and back comprises an extension of said back extending from a pivot point on said base to a support for said seat, which extension forms a forward facing angle of at least about 5°

with the plane of the top of said base.

4. The chair of claim 3 further comprising a pair of front legs pivotally connected to the front of said base and the front of said seat support and forming a forward facing angle of at least about 5°

with the plane of the top of said base.

5. A chair comprising:

a) a chair base;

b) a seat attached to said chair base;

c) a back attached to said chair;

d) a substantially C shaped upper rod wherein the approximate center of said substantially “

C”

shaped upper rod is attached to the back of said back;

e) a substantially C shaped lower rod wherein the approximate center of said substantially “

C”

shaped lower rod is attached to the back of said back below the point where said substantially “

C”

shaped upper rod is attached to the back of said back;

f) a left armrest attached to said substantially “

C”

shaped upper rod and said substantially “

C”

shaped lower rod near the end of said rods on the left side of said chair; and

g) a right armrest attached the said substantially “

C”

shaped upper rod and said substantially “

C”

shaped lower rod near the end of said rods on the right side of said chair.

6. The chair of claim 5 further comprising:

a back-arm interface positioned behind said chair back about 6 to 12 inches higher than said seat, said back-arm interface having a first aperture adapted to receive said substantially “

C”

shaped upper rod and a second aperture adapted to receive said substantially “

C”

shaped lower rod.

7. The chair of claim 5 further comprising:

in said back-arm interface a mechanism for fixing the position of said armrests.

8. The chair of claim 7 in which said mechanism for fixing the position of said armrests is disengaged by raising the distal end of said armrest and is re-engaged by releasing said armrest.

9. A chair comprising:

a) a chair base;

b) a seat attached to said chair base;

c) a back attached to said chair;

d) an approximately quarter circle shaped upper rod wherein the approximate center of said approximately quarter circle shaped upper rod is attached to the back of said back;

e) an approximately quarter circle shaped lower rod wherein the approximate center of said approximately quarter circle shaped lower rod is attached to the back of said back below the point where said approximately quarter circle shaped upper rod is attached to the back of said back; and

f) an armrest attached to said approximately quarter circle shaped upper rod and said approximately quarter circle shaped lower rod near the end of said rods.

10. The chair of claim 9 further comprising:

a back-arm interface positioned behind said chair back about 6 to 12 inches higher than said seat, said back-arm interface having a first aperture adapted to receive said approximately quarter circle shaped upper rod and a second aperture adapted to receive said approximately quarter circle shaped lower rod.

11. The chair of claim 9 further comprising:

in said back-arm interface a mechanism for fixing the position of said armrest.

12. The chair of claim 11 in which said mechanism for fixing the position of said armrest comprises a ratchet face and a ratchet surface.

13. The chair of claim 11 in which said mechanism for fixing the position of said armrest comprises a plurality of ratchet faces and ratchet surfaces.