Chair

• US 6,820,936 B2
• Filed: 06/30/2003
• Issued: 11/23/2004
• Est. Priority Date: 06/10/1994
• Status: Expired due to Fees

• Current Assignee: Haworth Incorporated
• Original Assignee: Haworth Incorporated
• Inventors: Wilkerson, Larry A., Roslund, Richard N. Jr.
• Primary Examiner(s): White, Rodney B.
• Application Number:
  US10/609,713
• Publication Number:
  US 20040095007A1
• Time in Patent Office: 512 Days
• Field of Search: 297/300.2, 297/300.4, 297/301.7, 297/302.7, 297/300.1, 297/316, 297/411.27, 297/411.28, 297/285, 297/286
• US Class Current: 297/300.2
• CPC Class Codes: A47C 1/03255 with a central column, e.g. rocking office chairs
• 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: A47C 1/03277 with bar or leaf springs

Abstract

An office-type chair which provides for synchronous differential tilting of the seat and back assemblies, with the seat assembly being constructed such that the front lip thereof does not significantly lift upon rearward tilting. The chair incorporates a tilt control mechanism formed by a control body which secures to the upper end of the chair pedestal and an upright which pivotally connects to the control body about an axis disposed forwardly of the pedestal. A pivot assembly connects the upright and control body together.

Claims

1. In an office-type chair having a base, a cantilevered pedestal assembly projecting upwardly from the base, and a seat-back arrangement connected to an upper end of said pedestal assembly, said seat-back arrangement including a generally horizontally enlarged seat assembly and a back assembly projecting upwardly from and adjacent a rear edge of said seat assembly, said seat assembly including therein a pair of housing parts which are rigidly joined together and positioned closely adjacent opposite side edges of the seat assembly, and a pair of exterior chair arms positioned adjacent opposite sides of the seat assembly and fixedly connected to the seat-back arrangement, each chair arm having an armrest portion disposed in upwardly spaced relationship from one side edge of the seat assembly and a support arm portion which projects downwardly from the armrest portion and at its lower end terminates in a mounting portion which attaches to the seat assembly adjacent one side thereof, the improvement comprising a fastener-free locking arrangement cooperating between said mounting portion and the respectively adjacent housing part for fixedly securing the mounting portion to the respective housing part, each said mounting portion including a bore and each said housing part including a rigid cantilevered shaft part which fits rotatably within said bore and rigidly supports said chair arm thereon, said locking arrangement including first and second lock parts which are fixedly associated with the respective mounting portion and housing part, said first and second lock parts being fixedly engageable due to relative rotative movement between said mounting portion and said housing part.

2. A chair according to claim 1, wherein said cantilevered shaft part projects horizontally outwardly from the respective housing part, said bore of said mounting portion being generally cylindrical so as to be axially slidably accommodated over said cantilevered shaft part in load bearing relation therewith.

3. A chair according to claim 2, wherein said chair arm includes a second support arm which is fixed to and projects cantilevered from the armrest and terminates in a mounting plate which projects into an adjacent side edge of the back assembly and is fixedly secured thereto.

4. A chair according to claim 1, wherein a control housing is disposed within the seat assembly and is fixed to the upper end of the pedestal, an upright member is positioned within said back assembly and projects downwardly into said seat assembly and is pivotally coupled to said control housing about a substantially horizontal pivot axis which extends transversely of the seat assembly, a horizontally extending support shaft defining said pivot axis and extending generally transversely across said seat assembly for pivotally coupling said upright to said control housing, said shaft having said cantilevered shaft parts which project outwardly at opposite ends thereof, said mounting portion comprising a hollow sleevelike hub with said bore defined therein wherein said hub is axially slidably telescoped onto and supported by the cantilevered shaft portion, said first lock part being fixed to said sleevelike hub, and said second lock part being fixed to said upright.

5. A chair according to claim 4, wherein said first lock part projects radially outwardly from said hub and said second lock part defines a circumferentially extending slot which is adapted to circumferentially receive said first lock part slidably therein during said rotative movement to prevent axial movement of said hub relative to said shaft part.

6. A chair according to claim 5, wherein said first lock part and said second lock part include camming surfaces which face axially in opposing relation to axially restrict movement of said hub relative to said shaft in response to said relative rotative movement of said mounting portion and said housing part.

7. In a chair having a base supportable on a floor and a seat-back arrangement connected to said base, said seat-back arrangement including a seat assembly and a back assembly projecting upwardly from said seat assembly, said chair further including a chair arm fixedly connected to said seat-back arrangement wherein said chair arm has an armrest portion spaced above said seat assembly and a support arm which projects downwardly from said armrest and has a mounting hub that attaches to said seat assembly, comprising the improvement wherein said seat assembly includes a cantilevered shaft which projects sidewardly from said seat assembly and defines a horizontal rotation axis, said hub including a bore which opens axially sidewardly such that said hub is axially slidable onto said shaft and is rotatable about said rotation axis which said chair arm being rigidly supported by said shaft, a fastener-free locking arrangement being provided between said hub and said seat assembly which said locking arrangement comprises first and second lock parts on said hub and said seat assembly respectively which are fixedly engageable with each other in response to relative rotative movement of said chair arm about said rotation axis.

8. A chair according to claim 7, wherein said back assembly is pivotally connected to said shaft so as to be tiltable rearwardly relative to said seat assembly about said rotation axis.

9. A chair according to claim 7, wherein said first and second lock parts comprise a radial projection which projects radially and a circumferential slot which opens radially towards said projection, said projection being slidable circumferentially into said slot during said rotative movement and being confined axially within said slot to prevent axial displacement of said chair arm.

10. A chair according to claim 9, wherein said projection and said slot include opposed camming surfaces which draw said hub axially inwardly toward said seat assembly in tight fitting engagement therewith.

11. A chair according to claim 7, wherein said chair arm is affixed to said seat-back arrangement by a fastener to prevent disengagement of said first and second lock parts as a result of rotative movement of said chair arm.

12. A chair according to claim 7, wherein said first and second lock parts are disposed radially outwardly of and separate from said shaft such that said shaft is independently rotatable relative to said first and second lock parts.

13. In a chair having a base and a seat-back arrangement connected to said base, said seat-back arrangement including a seat assembly and a back assembly projecting upwardly from said seat assembly, said seat assembly including a horizontal shaft to which said back assembly is rotatably connected, and said chair further including a chair arm fixedly connected to the seat-back arrangement wherein said chair arm has an armrest portion spaced above said seat assembly and a support arm which projects downwardly from said armrest, comprising the improvement wherein said shaft has shaft portions which project sidewardly from said seat assembly in cantilevered relation therewith and said support arm has a mounting hub which rotatably attaches to a respective one of said shaft sections, a locking arrangement being provided which cooperates between said hub and said seat assembly to axially secure said hub in position on said shaft section while permitting relative rotation between said shaft section and said hub, said locking arrangement comprising a first lock part which is fixed on said hub and a second lock part which is fixed on said seat assembly which said first and second lock parts are engageable one with the other by relative rotative movement between said hub and said seat assembly.

14. A chair according to claim 13, wherein said first lock part is a radial projection which projects radially outwardly from said hub and said second lock part is a slot formation defining a slot which extends circumferentially and allows for circumferential sliding of said projection therein to prevent axial displacement of said chair arm relative to said seat assembly.

15. A chair according to claim 13, wherein said chair arm is affixed to said seat assembly by a fastener after said first and second lock parts are engaged together to prevent disengagement of said first and second lock parts.

16. A chair according to claim 15, wherein said fastener is engaged between said chair arm and said back assembly.

17. A chair according to claim 13, wherein said hub has a bore which extends horizontally and slidably receives said shaft section in close fitting engagement therewith such that said chair arm is supported in load bearing relation on said seat assembly by said shaft section.

18. A chair according to claim 17, wherein said hub has an outer circumference and said first and second lock parts are disposed radially outwardly of said outer circumference.

19. The chair according to claim 17, wherein said seat assembly includes a side wall through which said shaft is rotatably supported, said side wall including said second lock part thereon.

20. A chair according to claim 13, wherein said back assembly includes a downwardly extending upright which has a lower end pivotally connected to said shaft.