Chair with arm mounted motion control

• US 5,516,196 A
• Filed: 02/14/1994
• Issued: 05/14/1996
• Est. Priority Date: 01/23/1992
• Status: Expired due to Fees

• Current Assignee: Steelcase Development Inc.
• Original Assignee: Steelcase Incorporated
• Inventors: Forslund, Carl V. III, Faiks, Frederick S., Feldpausch, Thomas G.
• Primary Examiner(s): Brittain, James R.
• Application Number:
  US08/195,931
• Time in Patent Office: 820 Days
• Field of Search: 297/286, 297/290, 297/296, 297/297, 297/300
• US Class Current: 297/286
• CPC Class Codes: A47C 7/441 with adjustable elasticity
• CPC Class Codes: A47C 7/445 with bar or leaf springs

Abstract

A chair is provided with a frame defining a curved arm support, a seat supported in the frame, and a back. An arm member is movably mounted on the arm support and operatively connected to the back so that movement of the back between upright and reclined positions is controlled by the arm member and arm support. A resilient spring is operatively connected to the back to bias the back towards an upright position. In one embodiment, the resilient spring encompasses the curved arm support and provides support for a seated user'"'"'s arm. In another embodiment, an arm cap covers the resilient spring. Optionally, the arm cap slideably rides on roller bearings over the curved arm support. In another embodiment, the curved arm support and arm member are telescopingly arranged, and the resilient spring is operably placed therein. Another embodiment includes first and second springs, the second springs being disengageable to produce discrete selectable levels of bias force for biasing the back toward the upright position. In another embodiment, the resilient spring is continuously adjustable, and includes a control mechanism including opposing springs that slide on a pivotable actuator arms thus creating a variable torque arm which is adjustable to vary the resulting bias force on the chair back.

Claims

1. A chair comprising:

a chair frame including armrests;

a seat, a back reclinable relative to said seat, and a flexible section interconnecting said seat and said back, said seat being operably movably connected to said chair frame at a first connection;

an energy source operably connected to said frame and said back for generating a force to bias said back forwardly to dynamically support said back and a person leaning on said back; and

guide means defining a curvilinear path located on said armrests for guiding said back and said seat as said back is tilted rearwardly, said armrests defining bearing surfaces and said guide means including bearing plates attached to said back and continuously slideably engaging said bearing surfaces so that the relative positions of said back and said seat are a function of said first connection, said flexible section, and said guide means.

2. A chair as defined in claim 1 including a unitary shell defining said seat, said reclinable back, and said flexible section.

3. A chair as defined in claim 1 wherein said energy source is located below said seat, and including straps extending along said armrests connecting said energy source to said back.

4. A chair as defined in claim 1 wherein said energy source includes a resilient elastic energy source extending along said armrests.

5. A chair as defined in claim 4 wherein said energy source is located inside said armrest.

6. A chair as defined in claim 4 wherein said energy source is located on said armrest.

7. A chair as defined in claim 1 wherein said first connection includes a pivot connecting said seat and said frame.

8. A chair comprising:

a frame including armrests;

a seat supported on said frame;

a tiltable back movably supported on said frame and movable between upright and reclined positions; and

a control mechanism including guide means located on said armrests for guiding said back along a curvilinear path during movement between said upright and reclined positions, and further including resilient means for continuously dynamically supporting said back and a person leaning on said back as said back is moved away from said upright position, said resilient means being associated with said armrests and being operably connected to said guide means, said armrests defining bearing surfaces and said guide means including bearing plates attached to said back and continuously slideably engaging said bearing surfaces.

9. A chair as defined in claim 8 including a leaf spring operably interconnecting to said seat and said back.

10. A chair as defined in claim 8 wherein said resilient means is preloaded to provide an initial level of support before said back begins to recline.

11. A chair as defined in claim 8 including a shell defining said seat and said back.

12. A chair comprising:

a frame defining a non-linear support;

a seat supported on said frame, said seat having a front portion and a rear portion, said front portion being fixed relative to said frame;

a back adapted to move between upright and reclined positions, said rear portion being operably connected to said back;

resilient means operatively connected to said back for biasing said back towards said upright position and for dynamically supporting said back and a person leaning on said back; and

said back being operatively connected to and guided by said non-linear support such that said rear portion of said seat flexes downwardly as said back moves toward said reclined position.

13. A chair as defined in claim 12 including a shell defining said seat and said back.

14. A chair as defined in claim 12 wherein said resilient means is preloaded when in said upright position.

15. A chair as defined in claim 12 wherein said resilient means is located below said seat.

16. A chair as defined in claim 12 wherein said resilient means is located along said non-linear support.

17. A chair as defined in claim 12 wherein said non-linear support defines an armrest.

18. A chair as defined in claim 12 including a pair of said non-linear supports, each defining an armrest.

19. A chair as defined in claim 12 including an arm member movably mounted on said non-linear support and operably connected to said back for guiding said back as said back is moved.

20. A chair comprising:

a frame defining a non-linear support;

a seat supported on said frame, said seat having a front portion and a rear portion, said front portion being fixed relative to said frame;

a back configured to move freely between upright and reclined positions, said rear portion being operably connected to said back;

resilient means operatively connecting said back to said rear portion of said seat for biasing said back towards said upright position and for dynamically supporting said back and a person leaning on said back, said resilient means being configured to flex as said back moves toward said reclined position; and

said back being operably secured to and guided by said non-linear support such that, as said back follows said non-linear support as said back moves toward said reclined position, said rear portion of said seat flexes to allow such movement.

21. A chair as defined in claim 20 wherein said resilient means is preloaded when in said upright position.

22. A chair as defined in claim 20 wherein said resilient means is located below said seat.

23. A chair as defined in claim 20 wherein said resilient means is located along said non-linear arm support.

24. A chair as defined in claim 20 wherein said non-linear support defines an armrest.

25. A chair as defined in claim 20 including a pair of said non-linear supports, each defining an armrest.

26. A chair as defined in claim 20 including an arm member movably mounted on said non-linear support and operably connected to said back for guiding said back as said back is moved.

27. A chair comprising:

a frame defining a substantially rigid, non-linear arm support, said arm support including a bearing surface;

a generally unitary, support shell defining a seat and back, said seat having a front portion and a rear portion, said front portion being supported on said frame and attached at a known location relative to said non-linear arm support, said back being adapted to move between upright and reclined positions;

resilient means operatively connected to said back for biasing said back towards said upright position and for continuously dynamically supporting said back and a person leaning on said back as said back is moved away from said upright position; and

an arm member movably mounted on said non-linear arm support, said arm member including a bearing plate continuously slideably engaging said bearing surface for movement therealong, said arm member being operatively connected to said back and guided by said non-linear arm support such that, as said back moves toward said reclined position, the distance along said non-linear arm support between the point at which the front portion of said seat is positioned relative said curved arm support and the point at which said arm member is mounted on said non-linear arm support increases at a predetermined rate, thus resulting in said seat rotating at a first angular rate different than a second angular rate of said back.