초록 ▼

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 w

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.

대표청구항 ▼

What is claimed is: 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 com

What is claimed is: 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 body 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 body 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 body 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. 2. The tilt control mechanism according to claim 1, wherein said stop mechanism defines a forward tilt control to limit forward tilting of said seat and back assemblies relative to the normal tilt position thereof. 3. The tilt control mechanism according to claim 1, wherein said stop mechanism defines a rearward tilt control to limit rearward tilting of said seat and back assemblies relative to the normal tilt position thereof. 4. 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. 5. 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 to separately control forward tilting and rearward tilting of said seat and back assemblies relative to the normal tilt position. 6. The tilt control mechanism according to claim 1, wherein said 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 engagement section is engagable and disengageable with said control plate upon pivoting movement of said lever. 7. The tilt control mechanism according to claim 6, 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 to stop movement of said control plate and thereby stop tilting of said seat and back assemblies. 8. The tilt control mechanism according to claim 7, wherein said control plate is a rotatable plate connected to said frame member so as to rotate about said pivot axis. 9. The tilt control mechanism according to claim 6, 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. 10. The tilt control mechanism according to claim 1, wherein said stop mechanism includes a slide member which is slidable along said control body wall surface and has said 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. 11. The tilt control mechanism according to claim 10, 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. 12. The tilt control mechanism according to claim 11, wherein said slide 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. 13. The tilt control mechanism according to claim 12, wherein said lock mechanism is displaceable transversely relative to said slidable member into and out of engagement therewith. 14. 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 defined on opposite sides by first and second wall surfaces, 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, substantially parallel relation with said first wall surface of said bottom body wall, said control plate being a rotatable plate connected to said frame member so as to rotate about said pivot axis, said control plate including a stop part which moves with said control plate along said first 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 has 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. 15. The tilt control mechanism according to claim 14, wherein said stop mechanism is mounted to said second wall surface which includes a window opening toward said stop part of said control plate, said engagement section projecting through said window to selectively engage said stop part. 16. The tilt control mechanism according to claim 14, wherein said first wall surface defines an interior of said control body, and said second wall surface is disposed on an exterior thereof. 17. The tilt control mechanism according to claim 15, wherein said tilt control mechanism includes a housing which mounts to said control body on an exterior thereof and covers said stop mechanism. 18. The tilt control mechanism according to claim 14, wherein said stop mechanism defines a forward tilt control to limit forward tilting of said seat and back assemblies relative to the normal tilt position thereof. 19. The tilt control mechanism according to claim 14, wherein said stop mechanism defines a rearward tilt control to limit rearward tilting of said seat and back assemblies relative to the normal tilt position thereof. 20. 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 having an arcuate section defined on opposite sides by first and second wall surfaces, and said frame member including an arcuate control plate which moves in unison with said frame member so as to pivot about said pivot axis, wherein said control plate includes an arcuate plate surface extending in opposing, substantially parallel relation with said first wall surface of said bottom body wall, said control plate including a stop part which moves with said control plate through an arcuate path along said first 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, said stop mechanism having a low-profile engagement member which has a stop part extending transversely relative to said bottom wall through said bottom wall and into said control plate to cooperate with said stop part, said stop mechanism actuatable between locked and unlocked conditions to selectively confine movement of said control plate when in said engagement position and thereby limit movement of said seat assembly and said back assembly. 21. The tilt control mechanism according to claim 20, wherein said stop mechanism includes a manual actuator for actuating said stop mechanism between the locked and unlocked conditions. 22. The tilt control mechanism according to claim 20, wherein said stop mechanism defines a forward tilt control to limit forward tilting of said seat and back assemblies relative to the normal tilt position thereof. 23. The tilt control mechanism according to claim 20, wherein said stop mechanism defines a rearward tilt control to limit rearward tilting of said seat and back assemblies relative to the normal tilt position thereof. 24. The tilt control mechanism according to claim 20, which includes a pivot shaft pivotally connecting said frame member to said control body, which said pivot shaft rotates about and defines said pivot axis. 25. The tilt control mechanism according to claim 24, wherein said control plate includes an arcuate main plate body, defining said arcuate plat surfaces, and wherein said control plate projects radially from said main plate body to said pivot shaft and is fixedly connected to said pivot shaft to effect rotation of said control plate about said pivot axis. 26. A low-profile tilt control mechanism for a chair having a seat-back assembly comprising a seat assembly and a back assembly interconnected to said tilt control mechanism wherein said seat-back assembly comprises a body support which defines a body support surface for one of a seat and back of a body of a chair occupant such that said body support is 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 body support, said control body including a body wall which faces vertically, and said frame member including a control plate which moves in unison with said frame member along said body wall wherein said control plate includes a plate surface which faces vertically and extends in opposing relation with an opposing bottom wall surface of said body wall so as to move along said wall surface during rearward recline of said body support, 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 body 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 body support. 27. The tilt control mechanism according to claim 26, wherein said stop mechanism defines a forward tilt control to limit forward tilting of said body support relative to the normal tilt position thereof. 28. The tilt control mechanism according to claim 26, wherein said stop mechanism defines a rearward tilt control to limit rearward tilting of said body support relative to the normal tilt position thereof. 29. The tilt control mechanism according to claim 26, 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 so that said projection is received in said window to define a forwardmost limit and a rearmost limit of tilting of said body support relative to the normal tilt position. 30. The tilt control mechanism according to claim 26, wherein said stop mechanism comprises an elongate lever which extends generally parallel to said wall surface and is pivotally attached to said control body such that said engagement section is engagable and disengageable with said control plate upon pivoting movement of said lever. 31. The tilt control mechanism according to claim 30, 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 to stop movement of said control plate and thereby stop tilting of said seat and back assemblies.