Combined tension and back stop function for seating unit

• US 6,932,430 B2
• Filed: 03/03/2004
• Issued: 08/23/2005
• Est. Priority Date: 09/12/2002
• Status: Expired due to Term

• Current Assignee: Steelcase Incorporated
• Original Assignee: Steelcase Development Corporation (Steelcase Incorporated)
• Inventors: Johnson, Eric, Heidmann, Kurt R., Peterson, Gordon J., Hall, Jeffrey A., Battey, Robert J., Bodnar, David A., Bedford, Adam C., Karsten, Gary Lee, Hadley, Jonathan B.
• Primary Examiner(s): WHITE, RODNEY BARNETT
• Application Number:
  US10/792,309
• Publication Number:
  US 20040245827A1
• Time in Patent Office: 538 Days
• Field of Search: 297/285, 297/286, 297/289, 297/300.6, 297/300.7, 297/300.8, 297/301.5, 297/301.6, 297/301.7
• US Class Current: 297/300.2
• 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 for increasing the supporting force, and still further includes a stop member and a selector device for activating and deactivating the booster mechanism. The selector device is easily movable with a low effort that is independent from friction generated by internal components of the booster mechanism. The stop member is linearly slidably mounted atop a control housing for selectively engaging the booster mechanism and the link for movement between a disengaged position, a booster-engaged 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 synchronous movement as the back is moved between upright and recline positions;

the control including a housing, a first mechanism providing a biasing supporting force to the back during recline, and a booster spring mechanism for increasing the supporting force;

an on/off selector device for selectively activating and deactivating the booster spring mechanism includes a stop member slidably mounted to the housing and that is movable to a self-sustaining disengaged first position for deactivating the booster spring mechanism and an engaged second position for activating the booster spring mechanism; and

the booster spring mechanism operably connected to the back for rotation therewith during recline of the back, the booster spring mechanism defining an axis of rotation and including an arm extending from the axis of rotation that freely rotates when the stop member is in the disengaged first position, but that when in the second position, engages the stop member to tension the booster spring mechanism upon recline of the back.

2. The seating unit defined in claim 1, wherein the on/off selector device includes a cable for moving the stop member between the engaged and disengaged positions.

3. The seating unit defined in claim 2, wherein the control further includes a link that rotates with the back during recline, and wherein the stop member includes a first step shaped to operably selectively engage the link to limit recline of the back when the link is moved to a third position.

4. The seating unit defined in claim 3, wherein the first step, when engaged with the link, limits the back to a partial recline position.

5. The seating unit defined in claim 4, wherein the stop member includes a second step that, when engaged with the link, limits the back to a zero recline.

6. The seating unit defined in claim 5, wherein the on/off selector device includes a manually operable hand control.

7. The seating unit defined in claim 6, wherein the hand control includes a detent device operably engaging the hand control.

8. The seating unit defined in claim 1, wherein the stop member is slidably mounted within the housing for lateral sliding movement.

9. The seating unit defined in claim 1, including a link operably coupled to the base and to the seat.

10. 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.

11. 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 first adjustment mechanism for adjusting a first control member on the chair, and a second mechanism for adjusting a second control member on the chair, the improvement comprising:

a single actuator operably coupled to both the first adjustment mechanism and the second mechanism selectively operating one of said mechanisms when in a first position and selectively operating both of said mechanisms when in a second position.

12. The seating unit defined in claim 11, wherein the first mechanism includes an energy adjustment mechanism for biasing the back, and the second mechanism includes a back stop mechanism for limiting recline of the back.

13. The seating unit defined in claim 12, wherein the actuator includes a stop member that, when in a first position is totally disengaged, but when in a second operative position, engages both the energy adjustment mechanism and back stop mechanism.

14. The seating unit defined in claim 12, wherein the stop member is movable to a disabled position where the actuator disengages from the energy adjustment mechanism and from the back stop mechanism.

15. A seating unit comprising:

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 adjustable component, a stop member engaging the adjustable component, and an actuator adjusting the stop member into engagement with the adjustable component;

the actuator including a handle operating the stop member and an over-torque mechanism connecting the handle to the stop member; and

the over-torque mechanism releasing and preventing damage to the stop member and to the actuator and to the adjustable component when a damaging excessive force is transmitted by the handle but when the stop member is prevented from moving.

16. The seating unit defined in claim 15, including a cable having a first end connected to the stop member and a second end connected to the handle.

17. The seating unit defined in claim 15, including a detent associated with the handle and operably engaging the handle to generate uneven forces upon rotation of the handle so as to provide a detented feel to a seated user.

18. The seating unit defined in claim 15, wherein the over-torque mechanism operates in two directions.

19. The seating unit defined in claim 15, wherein the actuator includes a detent for holding the handle in a newly selected position even though the adjustable component temporarily cannot be moved, and wherein the over-torque mechanism is configured to bias the adjustable component to a position corresponding to the newly selected position when the adjustable component is able to be moved.

20. The seating unit defined in claim 15, wherein the underseat control includes a housing with walls defining a cavity opening downwardly and a cover for closing the cavity;

the stop member being positioned within the cavity and adjustably mounted on at least one rod therein.