Combined tension and back stop function for seating unit

• US 20040245839A1
• Filed: 06/05/2003
• Published: 12/09/2004
• Est. Priority Date: 09/12/2002
• Status: Active Grant

• Current Assignee: Steelcase Incorporated
• Original Assignee: Steelcase Development Corporation (Steelcase Incorporated)
• Inventors: Heidmann, Kurt R., Bodnar, David A., Bedford, Adam C., Karsten, Gary L.
• Granted Patent: US 6,880,886 B2
• Time in Patent Office: Days
• US Class Current: 297/452.63
• 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 1/03238 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 1/03274 of torsion type
• CPC Class Codes: A47C 1/03294 slidingly movable in the base frame, e.g. by rollers
• CPC Class Codes: A47C 31/04 Clamps for attaching flat elastic strips or flat meandering springs to frames
• CPC Class Codes: A47C 7/14 of adjustable shape; elastically mounted ; adaptable to a user contour or ergonomic seating positions movably-coupled seat and backrests with elastic adjustment means A47C1/03261; elastically-mounted back-rests or backrest-seat units in the base frame A47C7/44
• CPC Class Codes: A47C 7/28 with tensioned springs, e.g. of flat type
• CPC Class Codes: A47C 7/38 for the head adjustable coupled to reclining or easy chairs A47C1/036
• CPC Class Codes: A47C 7/46 with special, e.g. adjustable , lumbar region support profile; "Ackerblom" profile chairs

Abstract

A seating unit includes a base, a seat, a back, and a control operably supporting the seat and the back on the base for movement between upright and recline positions. The control includes a spring providing a biasing supporting force to the back during recline, and further includes a booster mechanism capable of increasing the supporting force, and still further includes a selector device for activating and deactivating the booster mechanism. The selector device is easily moveable with a low effort that is separated from and independent from any friction generated by internal components of the booster mechanism. In a narrower aspect, the control is powered, such as by an electrical or electromechanical device from a remote location. A back stop is attached to the selector device, for movement between a disengaged position, a partial-recline position, and a recline-prevented position.

Claims

1. A seating unit comprising:

a base, a seat, a back, and a control operably supporting the seat and the back on the base for movement between upright and recline positions;

the control including a first mechanism providing a biasing supporting force to the back during recline, and further including a booster spring mechanism capable of increasing the supporting force, and still further including an on/off selector device for selectively activating and deactivating the booster spring mechanism.

2. The seating unit defined in claim 1, wherein the on/off selector device is moveable with a low effort that is separated from and independent from any friction generated by spring components of the booster spring mechanism.

3. The seating unit defined in claim 2, wherein the booster spring mechanism includes an resilient spring, and the on/off selector device comprises a stop engageable with the spring.

4. The seating unit defined in claim 3, wherein the spring comprises a torsion spring.

5. The seating unit defined in claim 4, wherein the control further includes a back stop, and wherein the control is operably to selectively engage the back stop to limit recline of the back.

6. The seating unit defined in claim 5, wherein the back stop includes a first step limiting the back to a partial recline.

7. The seating unit defined in claim 6, wherein the back stop includes a second step limiting the back to a zero recline.

8. The seating unit defined in claim 1, wherein the on/off selector device includes a manually operable hand control.

9. The seating unit defined in claim 8, wherein the hand control includes a single knob.

10. The seating unit defined in claim 8, wherein the hand control includes a detented handle.

11. The seating unit defined in claim 8, wherein the hand control includes a handle and a clutch operably supported within the handle.

12. The seating unit defined in claim 1, including a link operably coupled to the base and to one of the seat and the back.

13. The seating unit defined in claim 12, including a back stop movable between a disengaged position permit full recline of the back and an engaged position limiting recline of the back, and wherein the link includes an arm that engages the back stop when the back stop is engaged.

14. The seating unit defined in claim 1, including compliant arms extending from the base and supporting at least one of the seat and back for movement upon recline.

15. The seating unit defined in claim 1, including a pivot pin keyed to and supporting the link;

and wherein the booster spring mechanism includes a torsion spring keyed to the pivot pin, the torsion spring having a protrusion, and wherein the on/off selector device engages the protrusion to activate the torsion spring.

16. The seating unit defined in claim 1, wherein the control includes a powered mechanism for powered engagement and disengagement of the booster mechanism.

17. The seating unit defined in claim 16, wherein the powered mechanism includes an electromechanical device adapted to engage and disengage the booster spring mechanism.

18. A seating unit comprising:

a base, a seat, a back, and a control operably supporting the seat and back on the base for movement between upright and recline positions;

the control including a link pivoted to the seat at one end and pivoted to the base at another end, the control including a first mechanism adapted to provide a biasing supporting force during recline and further including a booster spring mechanism operably attached to the link, the booster mechanism comprising a torsion spring and a stop selectively engageable with the torsion spring to activate the torsion spring to boost and increase the supporting force provided to a seated user during recline.

19. The seating unit defined in claim 18, wherein the stop forms an on/off device for selectively activating or deactivating the booster mechanism.

20. The seating unit defined in claim 18, wherein the control includes flexible arms supporting at least one of the back and seat on the base.

21. The seating unit defined in claim 20, wherein the link includes an arm engageable with a second stop to limit recline of the back.

22. The seating unit defined in claim 20, wherein the flexible arms are resilient and absorb energy upon recline.

23. The seating unit defined in claim 18, including an actuator operably coupled to the stop and having a remote handle for operating the stop.

24. The seating unit defined in claim 18, wherein the base includes castors for engaging a floor surface.

25. A control for adjustably supporting a movable structural component on a base of a seating unit, comprising:

a pivot pin adapted to be rotatably supported on one of the base and the structural component, and that is rotatably coupled to the other of the base and the structural component for coordinated rotation therewith during recline;

a torsion spring having an inner ring keyed to the pivot pin, an outer second ring having a protrusion extending from the outer second ring, and a resilient spring portion operably interconnecting the inner and outer rings; and

a booster stop operably coupled to the one of the structural component and the base, the booster stop being movable between a disengaged position where the protrusion misses and passes by the booster stop when the pivot pin is rotated as the structural component is moved, and an engaged position where the protrusion engages the booster stop and prevents the outer second ring on the torsion spring from rotating, which thus activates the torsion spring to provide a bias when the structural component is moved, whereby the torsion spring can be selectively engaged and disengaged to adjust a biasing force on the structural component.

26. The control defined in claim 25, including a selector coupled to the booster stop for moving the booster stop between the disengaged and engaged positions, whereby the torsion spring can be engaged and disengaged to adjust a biasing force on the structural component.

27. The control defined in claim 26, including a reclineable back and a back stop operably mounted adjacent the booster stop and movable to limit recline of the back.

28. The control defined in claim 27, wherein the back stop has a partial-recline position where the back is limited to a partial recline, and a zero-recline position where the back is prevented from any recline.

29. The control defined in claim 25, including an electromechanical device coupled to the booster stop and adapted to move the booster stop between the engaged and disengaged positions.

30. A seating unit comprising:

a base;

a seat;

a back;

a control supporting the back on the base for movement between upright and reclined positions, the control including a plurality of mechanisms including first and second energy mechanisms for biasing the back toward the upright position, and a back stop mechanism for limiting movement of the back to a position short of the reclined position; and

a single selector device operably connected to said plurality of mechanisms for selectively activating said plurality of mechanisms.

31. The seating unit defined in claim 30, wherein the selector device is movable to at least one position where the first energy mechanism is simultaneously activated with at least one of the second energy mechanism and the back stop mechanism.

32. The seating unit defined in claim 30, wherein the selector device is movable to at least one position where the first and second energy mechanisms and the back stop mechanism are all simultaneously activated.

33. The seating unit defined in claim 30, wherein the selector device is movable through a plurality of positions, each position sequentially activating an additional one of the mechanisms.

34. The seating unit defined in claim 30, wherein the selector device comprises an on/off selector moveable with a low effort that is separated from and independent from any friction generated by spring components of the first and second energy mechanisms.

35. The seating unit defined in claim 34, wherein the booster spring mechanism includes a resilient torsion spring, and the on/off selector device comprises a stop engageable with the spring.

36. The seating unit defined in claim 30, wherein the back stop mechanism further includes a stepped back stop member pivoted to the control.

37. The seating unit defined in claim 36, wherein the stepped back stop member includes a first step limiting the back to a partial recline, and a second step limiting the back to a zero recline.

38. The seating unit defined in claim 30, wherein the selector device includes a manually operated hand control with a single knob.

39. The seating unit defined in claim 30, including a link operably coupled to the base and to one of the seat and the back, and wherein the back stop mechanism includes a back stop member movable between a disengaged position that permits full recline of the back, and an engaged position limiting recline of the back, and wherein the link includes an arm that engages the back stop member when the back stop mechanism is engaged.

40. The seating unit defined in claim 30, including compliant arms extending from the base and supporting at least one of the seat and back for movement upon recline.

41. In a seating unit having a base, a seat, a back adapted to pivot between upright and reclined positions, an energy mechanism for biasing the back toward the upright position, a tension adjustment mechanism for adjusting the force biasing the back toward the upright position, and a back stop mechanism for limiting the range of motion of the back to a position short of the reclined position, the improvement comprising:

an actuator operably attached to both the tension adjustment mechanism and the back stop mechanism for operating said mechanisms.

42. The seating unit defined in claim 41, wherein the actuator comprises a single actuator.

43. The seating unit defined in claim 41, wherein the actuator is movable to at least one position where the first energy mechanism is simultaneously activated with at least one of the second energy mechanism and the back stop mechanism.

44. The seating unit defined in claim 41, wherein the actuator is movable to at least one position where the first and second energy mechanisms and the back stop mechanism are simultaneously activated.

45. The seating unit defined in claim 41, wherein the actuator is movable through a plurality of positions, each position sequentially activating an additional one of the mechanisms.

46. The seating unit defined in claim 41, wherein the actuator comprises an on/off selector moveable with a low effort that is separated from and independent from any friction generated by spring components of the first and second energy mechanisms.

47. The seating unit defined in claim 41, wherein the booster spring mechanism includes a resilient torsion spring, and the actuator comprises a stop member engageable with the spring.

48. The seating unit defined in claim 41, wherein the back stop mechanism further includes a stepped back stop member pivoted to the control, and wherein the actuator is operably connected to the stepped back stop member.

49. The seating unit defined in claim 48, wherein the stepped back stop member includes a first step limiting the back to a partial recline, and a second step limiting the back to a zero recline.

50. The seating unit defined in claim 41, wherein the actuator includes a manually operated hand control with a single knob.

51. The seating unit defined in claim 41, including a link operably coupled to the base and to one of the seat and the back, and wherein the back stop mechanism includes a back stop member connected to the actuator and movable between a disengaged position permit full recline of the back and an engaged position limiting recline of the back, and wherein the link includes an arm that engages the back stop member when the back stop mechanism is engaged.

52. In a seating unit having a base, a back, and an underseat control operably coupled to and supporting the back for movement between upright and reclined positions, the control including a housing, an energy adjustment mechanism and a back stop mechanism, an improvement comprising:

an actuator movable to a first operative position for selectively engaging the energy adjustment mechanism, and movable to a second operative position for selectively engaging the back stop mechanism.

53. The seating unit defined in claim 52, wherein the actuator, when in the second operative position, engages both the energy adjustment mechanism and back stop mechanism.

54. The seating unit defined in claim 52, wherein the actuator is movable to a disabled position where the actuator disengages from the energy adjustment mechanism and from the back stop mechanism.

55. The seating unit defined in claim 52, wherein the actuator is operably pivotally mounted to the housing.