Tilt control mechanism for a chair

• US 7,735,923 B2
• Filed: 03/10/2009
• Issued: 06/15/2010
• Est. Priority Date: 03/01/2005
• Status: Active Grant

• Current Assignee: Haworth Incorporated
• Original Assignee: Haworth Incorporated
• Inventors: Roslund, Richard N., Gundarapu, VijayKrishna, Guntur, Naveen, Rutman, Matthew
• Primary Examiner(s): WHITE, RODNEY BARNETT
• Application Number:
  US12/381,243
• Publication Number:
  US 20090179473A1
• Time in Patent Office: 462 Days
• Field of Search: 297/300.2, 297/300.4, 297/300.5, 297/300.6
• US Class Current: 297/300.2
• CPC Class Codes: A47C 1/03238 by means of peg-and-notch or pawl-and-ratchet mechanism
• 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 1/03266 with adjustable elasticity
• CPC Class Codes: A47C 1/03272 with coil springs
• CPC Class Codes: A47C 1/03274 of torsion type
• CPC Class Codes: A47C 1/03279 of torsion type
• CPC Class Codes: A47C 1/03294 slidingly movable in the base frame, e.g. by rollers
• CPC Class Codes: Y10T 74/20396 Hand operated

Abstract

A tilt control mechanism for an office chair includes a spring assembly therein which controls the tilt tension on the back assembly. The tilt control mechanism includes a control plate mounted to the control shaft on which the uprights are mounted, wherein the control plate rotates in combination with the uprights. This control plate is located within the control body and cooperates with a front stop assembly and a back stop assembly to vary the limits of forward and rearward tilting of the seat and back assemblies. Also, the tilt control mechanism includes a pneumatic actuator assembly having fixed and rotatable cam blocks. The rotatable cam block rotates relative to the fixed block such that the rotatable cam block is driven downwardly to depress the control valve of the pneumatic cylinder and thereby vary the height of the seat assembly.

Claims

1. A low-profile tilt control mechanism for a chair having a seat assembly and a back assembly interconnected by said tilt control mechanism such that said back assembly and said seat assembly are rearwardly reclinable from a normal tilt position, said tilt control mechanism comprising a control body and a chair frame member which is pivotally connected to said control body so as to pivot about a horizontal pivot axis during reclining of said seat assembly and said back assembly, said control body including a bottom wall, and said frame member including a control plate which moves in unison with said frame member wherein said control plate includes a plate surface extending in opposing relation with an opposing bottom wall surface of said bottom wall of said control body, said control plate including stop parts which move with said control plate along said bottom wall surface and said tilt control mechanism further including first and second stop mechanisms which are longitudinally elongate so as to lie along said bottom wall of said control body and each respectively having a low-profile engagement section which cooperates with a respective said stop part to selectively confine movement of said control plate and thereby limit movement of said seat assembly and said back assembly;

Said first stop mechanism defining a forward tilt control to limit forward tilting of said seat and back assemblies relative to the normal tilt position thereof; and

Said second stop mechanism defining a rearward tilt control to limit rearward tilting of said seat and back assemblies relative to the normal tilt position thereof.

2. The tilt control mechanism according to claim 1, wherein a projection is provided on one of said control body and said control plate and an elongate window is provided on the other of said control body and said control plate to define a forwardmost limit and a rearmost limit of tilting of said seat and back assemblies relative to the normal tilt position.

3. The tilt control mechanism according to claim 1, wherein said control plate is rotatable about said pivot axis and includes control parts to control the total range of tilting of said seat and back assemblies, and said stop parts separately control forward tilting and rearward tilting of said seat and back assemblies relative to the normal tilt position.

4. The tilt control mechanism according to claim 1, wherein said first stop mechanism comprises an elongate lever which extends generally parallel to said bottom wall surface and is pivotally attached to said control body such that said respective engagement section is engagable and disengageable with said control plate upon pivoting movement of said lever.

5. The tilt control mechanism according to claim 4, wherein said control plate includes a window therein which extends in said plane of movement of said control plate so as to terminate at opposite window edges, said lever being engagable into or disengageable out of said window, wherein said engagement section is movable within said window when said lever is engaged with said control plate until such engagement section abuts against a respective one of said window edges which defines a said stop part to stop movement of said control plate and thereby stop tilting of said seat and back assemblies.

6. The tilt control mechanism according to claim 5, wherein said control plate is a rotatable plate connected to said frame member so as to rotate about said pivot axis.

7. The tilt control mechanism according to claim 4, which further includes a biasing member which biases said lever in a first direction and includes an actuator device which displaces said lever opposite to said biasing force.

8. The tilt control mechanism according to claim 1, wherein said second stop mechanism includes a slide member which is slidable along said control body wall surface and has said respective engagement section engaged with said control plate such that tilting of said seat and back assemblies effects sliding movement of said slide plate, said stop mechanism further including a lock mechanism which is releasably engagable with said slide plate to releasably prevent movement of said slide plate and releasably confine movement of said control plate so as to limit tilting of said seat and back assemblies.

9. The tilt control mechanism according to claim 8, wherein said slide plate confines movement of said control plate in one direction of movement of said control plate while permitting movement of said control plate in a direction opposite thereto.

10. A low-profile tilt control mechanism for a chair having a seat assembly and a back assembly interconnected by said tilt control mechanism such that said back assembly and said seat assembly are rearwardly reclinable from a normal tilt position, said tilt control mechanism comprising a control body and a chair frame member which is pivotally connected to said control body so as to pivot about a horizontal pivot axis during reclining of said seat assembly and said back assembly, said control body including a bottom wall and said frame member including a control plate which moves in unison with said frame member wherein said control plate includes a plate surface extending in opposing relation with an opposing bottom wall surface of said bottom wall, said control plate including a stop part which moves with said control plate along said bottom wall surface and said tilt control mechanism further including a stop mechanism which is longitudinally elongate so as to lie along said bottom wall of said control body and having a low-profile engagement section which cooperates with said stop part to selectively confine movement of said control plate and thereby limit movement of said seat assembly and said back assembly as said stop part moves with said control plate into cooperation with said engagement section, said stop mechanism comprising a slidable member which defines said engagement section and is slidable along said bottom wall surface during relative tilting of said seat and back assemblies, said slidable member being displaceable by tilting of said seat and back assemblies, and said stop mechanism further including a lock mechanism which is releasably engagable with said slidable member to prevent movement of said slidable member and thereby confine movement of said seat and back assemblies.

11. The tilt control mechanism according to claim 10, wherein said slidable member is movable through multiple positions and stopped in any one of said positions by said lock mechanism to define a selected stop position which limits rearward tilting of said seat and back assemblies.

12. The tilt control mechanism according to claim 11, wherein said lock mechanism is displaceable transversely relative to said slidable member into and out of engagement therewith.

35. The tilt control mechanism according to claim 10, wherein said control plate includes a stop opening which moves with said control plate and defines said stop part, said engagement section of said slidable member extending into said stop opening and being relatively displaceable along said stop opening during movement of said control plate and relatively displaceable into contact with said stop part to define a stop limit at which movement of said seat assembly and back assembly is limited.

36. The tilt control mechanism according to claim 10, wherein said slidable member is movable by cooperation with said stop part of said control plate through multiple positions when said lock member is out of engagement with said slidable member, and wherein said slidable member is stopped in one of said positions when said lock member is engaged with said slidable member.

37. The tilt control mechanism according to claim 36, wherein said slidable member confines movement of said control plate in one direction of movement of said control plate while permitting movement of said control plate in a direction opposite thereto.

13. A low-profile tilt control mechanism for a chair having a seat assembly and a back assembly interconnected by said tilt control mechanism such that said back assembly and said seat assembly are rearwardly reclinable from a normal tilt position, said tilt control mechanism comprising a control body and a chair frame member which is pivotally connected to said control body so as to pivot about a horizontal pivot axis during reclining of said seat assembly and said back assembly, said control body including a bottom wall and said frame member including a control plate which moves in unison therewith wherein said control plate includes a plate surface extending in opposing relation with an opposing wall surface of said bottom wall of said control body, said control plate including a stop part which moves with said control plate along said bottom wall surface and said tilt control mechanism further including a stop mechanism which is longitudinally elongate so as to lie along said bottom wall of said control body and having a low-profile engagement section which cooperates with said stop part to selectively confine movement of said control plate and thereby limit movement of said seat assembly and said back assembly, said control plate being rotatable about said pivot axis during tilting of said seat and back assembly, and said stop mechanism comprising a pivotable lever which is pivotally connected to said control body and is movable toward and away from said bottom wall to move said engagement section into and out of engagement with said control plate, said stop part and said engagement member comprising one or the other of a window and a projection wherein engagement of said projection with said window confines tilting of said seat and back assemblies.

14. The tilt control mechanism according to claim 13, wherein engagement of said projection with said window prevents forward tilting of said seat and back assemblies from the normal tilt position.

15. The tilt control mechanism according to claim 14, wherein said stop mechanism includes a biasing member which urges said lever out of engagement with said control plate to permit said lever and said control plate to remain engaged if binding occurs between said lever and said control plate.

16. In a chair having a chair control mechanism with first and second operative conditions and an actuator assembly for actuating said chair mechanism between said first and second operative conditions, said actuator assembly comprising an actuator cable having an outer sheath and an interior cable wire disposed therein, said actuator assembly further including a cable connector arrangement comprising a cable mount disposed proximate said chair control mechanism which said cable mount includes an elongate channel defined between channel side walls wherein at least one of said side walls includes a plurality of teeth extending in a longitudinal row, said cable connector arrangement further including a connector block mounted to said cable sheath which said connector block is selectively positionable within said channel in a fixed position, said connector block including a plurality of teeth adapted to cooperate with said teeth of said cable mount such that the longitudinal position of said connector block within said channel is adjustable, said connector block being insertable into said channel by manipulation of said block in a desired lengthwise position wherein said connector block is restrained in said position by interfitting engagement between said teeth of said connector block and said cable mount.

17. A cable connector arrangement according to claim 16, wherein said interior cable wire has a first end projecting outwardly of said connector block into engagement with said chair control mechanism.

18. A cable connector arrangement according to claim 17, wherein said actuator assembly includes an actuator and said interior cable wire is connected to said actuator wherein actuation of said actuator changes said chair control mechanism between said first and second operative conditions.

19. A cable connector arrangement according to claim 17, wherein said longitudinal position of said connector block adjusts a position of said outer sheath relative to said first end of said interior cable wire.

20. A cable connector arrangement according to claim 16, wherein said connector block includes resilient cantilevered fingers having said teeth disposed thereon wherein said fingers are pressable together to permit insertion into said channel and are biased outwardly to maintain said teeth of said connector block and said cable mount in interconnected engagement.

21. The cable connector arrangement according to claim 16, wherein said connector block has an engagement portion along one side thereof which is engagable with said cable mount and permits rotation of said connector block about a rotation axis parallel to the longitudinal axis of said cable wherein said rotation of said connector block rotates said connector block into said channel and engages said teeth of said connector block with said teeth of said cable mount.

22. The cable connector arrangement according to claim 21, wherein said engagement portion comprises an elongate rib which is hooked into engagement with a corresponding rib on said cable mount which said ribs define said rotation axis.

23. A clustered handle assembly for a chair, said chair having a multi-function control mechanism comprising first, second and third mechanisms, said handle assembly comprising:

a mounting body having an elongate guide shaft which defines a rotation axis extending axially therethrough, and first and second rotatable handles rotatably supported on an exterior surface of said guide shaft, said first rotatable handle being connected to said first mechanism and said second rotatable handle connected to said second mechanism, said guide shaft further including a bore extending coaxially therethrough wherein a third rotatable handle is disposed with a shaft thereof extending interiorly through said bore for rotation about said rotation axis, said third handle being connected to said third mechanism.

24. The clustered handle assembly according to claim 23, wherein said first and second mechanisms control front and rear stop positions defined by said control mechanism for forward and rearward tiling of said chair.

25. The clustered handle assembly according to claim 24, wherein said third mechanism controls resistance to tilting defined by said control mechanism which resists rearward tiling of said chair.

26. The clustered handle assembly according to claim 23, wherein said first, second and third rotatable handles rotate coaxially about said rotation axis.

27. The clustered handle assembly according to claim 23, wherein said second rotatable handle comprises a ring section on one end and a handle section on an opposite end which join together and rotate in unison, said ring section being disposed on one side of said first rotatable handle and said handle section being disposed another side of said first rotatable handle such that said second rotatable handle is rotatably supported over the exterior surface of said guide shaft of said mounting body, and said first rotatable handle rotates over an exterior surface of said second rotatable handle.

28. The clustered handle assembly according to claim 27, wherein said first and second handles respectively include circumferential first and second cam arrangements thereon which are each engaged by resiliently movable biasing sections, said biasing sections respectively cooperating with said first and second cam arrangements such that each of said first and second handles snap over center between first and second operative positions corresponding to plural operative conditions of said first and second mechanisms, said first cam arrangement being defined on said first rotatable handle, and said second cam arrangement being defined on said ring section.

29. The clustered handle assembly according to claim 23, wherein said first and second handles each include a circumferential cam arrangement thereon which are each engaged by resiliently movable biasing member, said biasing member cooperating with said cam arrangements such that each of said first and second handles snap over center between first and second operative positions corresponding to plural operative conditions of said first and second mechanisms.

30. The clustered handle assembly according to claim 29, wherein said biasing member has first and second biasing sections which respectively cooperate with said cam arrangement of said first and second rotatable handles.

31. The clustered handle assembly according to claim 30, wherein said cam arrangements each include flat facets extending circumferentially one next to the other and said first biasing section cooperates with said facets of said first rotatable handle and said second biasing section cooperates with said facets of said second rotatable handle.

32. The clustered handle assembly according to claim 31, wherein each of said cam arrangements includes a pair of said facets separated by an intermediate peak wherein the respective one of the first and second biasing sections reversibly travels over center from one of said facets over said peak to the other of said facets of said respective pair.

33. The clustered handle assembly according to claim 29, wherein said cam arrangements each include flat facets extending circumferentially one next to the other and said respective biasing member cooperates with said facets.

34. The clustered handle assembly according to claim 23, wherein first and second cables are connected to said mounting body in parallel relation, said mounting body further including cable guides which route interior cable wires of said cables in opposite circumferential directions about said guide shaft.