Comfort surface for seating

• US 7,334,845 B2
• Filed: 05/14/2004
• Issued: 02/26/2008
• Est. Priority Date: 09/12/2002
• Status: Active Grant

• Current Assignee: Steelcase Incorporated
• Original Assignee: Steelcase Development Corporation (Steelcase Incorporated)
• Inventors: Heidmann, Kurt R., Peterson, Gordon J., Norman, Christopher J., Smith, Bruce M., Beukema, Steven James, Tubergen, Renard G.
• Primary Examiner(s): Dunn; David
• Assistant Examiner(s): Abraham; Tania
• Application Number:
  US10/846,784
• Publication Number:
  US 20040245841A1
• Time in Patent Office: 1,383 Days
• Field of Search: 297/452.63, 297/452.3, 297/452.52, 297/440.1, 297/452.51, 297/452.56, 297/452.54, 519/0, 519/1, 248/118
• US Class Current: 297/452.63
• CPC Class Codes: A47C 31/04 Clamps for attaching flat elastic strips or flat meandering springs to frames
• CPC Class Codes: A47C 7/029 of non-adjustable shape adapted to a user contour or ergonomic seating positions
• CPC Class Codes: A47C 7/28 with tensioned springs, e.g. of flat type
• CPC Class Codes: A47C 7/32 with tensioned cords, e.g. of elastic type, in a flat plane
• 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 perimeter frame, a flexible seating surface supported by the frame, and parallel elongated resilient force-distributing members coupled to the seating surface to control a contour of the seating surface when supporting a seated user. The resilient force-distributing members are bendable along their length and are sufficient in number and distribution to substantially reduce localized deflection of the seating surface and thereby reduce pressure point contact felt by the seated user. The resilient force-distributing members can be wire rods, long strips, or other resilient material with memory. The resilient force-distributing members can be supported on opposing sides of the perimeter frame in various ways to reduce inward pressure on the opposing sides during flexure of the resilient force-distributing members, such as by providing on ends of the resilient force-distributing members one or more rotatable pivots, sliding support at ends of the resilient force-distributing members, stretchable rubber supports, and/or elastic fabric.

Claims

1. A seating unit comprising:

a back frame having at least one vertical side section forming a rearwardly concave shape in a lumbar region;

a flexible supporting surface supported by the frame;

a plurality of elongated resilient force-distributing members supported by the frame and having sufficient resilient stiffness to support a seated user when opposing ends of the force-distributing members are supported, the force-distributing members being associated with said supporting surface to control a contour of the supporting surface when supporting the seated user, the resilient force-distributing members being generally flexible and bendable along their length and being sufficient in number and distribution across the supporting surface so as to reduce localized deflection of the supporting surface and thereby reduce point contact pressure associated with the seated user; and

a tensioning component associated with the lumbar region of the back frame that engages at least some of the force-distributing members to cause the opposing ends of the some force-distributing members to move horizontally toward each other such that the some force-distributing members thus take on a more curved pretensioned supportive shape.

2. The seating unit defined in claim 1, wherein the at least one vertical side section includes opposing spaced-apart side frame members, and including a decoupling means for slidably supporting the opposing ends of the plurality of resilient force-distributing members on the opposing spaced-apart side frame members.

3. The seating unit defined in claim 2, wherein the at least one vertical side section includes opposing side frame members with a curvilinear shape that force the seating surface to take on a three-dimensional non-planar shape, while still allowing the seating surface to undergo additional movement from external loads.

4. The seating unit defined in claim 2, wherein the seating surface is non-planar and has a three-dimensional ergonomic shape.

5. The seating unit defined in claim 2, wherein the frame engages ends of the force-distributing members to limit a maximum deformation of the comfort surface.

6. The seating unit defined in claim 1, wherein the at least one vertical side section includes opposing spaced-apart side frame members, and including a decoupling means for rotatably supporting the opposing ends of the plurality of resilient force-distributing members on the opposing spaced-apart side frame members.

7. The seating unit defined in claim 1, wherein the at least one vertical side section includes opposing spaced-apart side frame members, and including a decoupling means for movably supporting the opposing ends of the plurality of resilient force-distributing members on the opposing spaced-apart side frame members, the decoupling means including stretchable elastic material supporting the ends of the resilient force-distributing members.

8. The seating unit defined in claim 1, wherein the frame comprises a back perimeter frame defining an opening over which the resilient members are positioned, the perimeter frame including the at least one vertical side section.

9. The seating unit defined in claim 1, including a wire strand with parallel long wire sections forming at least two adjacent ones of the resilient force-distributing members and forming an intermediate section interconnecting the at least two adjacent resilient force-distributing members.

10. The seating unit defined in claim 1, including end pieces attached to the ends of each of the resilient force-distributing members, the end pieces being separate molded components and configured to movably support the ends of the resilient force-distributing members.

11. The seating unit defined in claim 1, wherein the frame has spaced-apart side frame members;

and including a carrier carrying the resilient force-distributing members on the frame members;

the carrier decoupling the plurality of resilient force-distributing members from the side frame members so that when the resilient force-distributing members are flexed and bent, inward movement of the opposing ends of the resilient force-distributing members are permitted without an equivalent movement of the side frame members.

12. The seating unit defined in claim 1, including bearings on at least some of the ends of the resilient force-distributing members.

13. The seating unit defined in claim 12, including a bearing shoe attached to at least some of the ends of the resilient force-distributing members.

14. The seating unit defined in claim 13, wherein the bearing shoe is made of acetal.

15. The seating unit defined in claim 1, including a carrier engaging the ends of the resilient members and constructed to deform and absorb at least some of the forces caused by inward movement of the ends of the resilient force-distributing members when the resilient force-distributing members are flexed.

16. The seating unit defined in claim 15, wherein the carrier includes a resilient deformable block.

17. The seating unit defined in claim 15, wherein the carrier includes a sheet of material having the resilient force-distributing members attached to the sheet to retain a location of resilient force-distributing members.

18. The seating unit defined in claim 15, wherein the carrier includes a plurality of structural members, one of the structural members being attached to each end of each one of the resilient force-distributing members, and wherein the carrier further includes an interconnecting elongated member that extends parallel the side frame members and extends perpendicular a length direction defined by the resilient force-distributing members for interconnecting all adjacent ones of the structural members.

19. The seating unit defined in claim 15, wherein the resilient force-distributing members comprise transverse sections of a continuous serpentine wire and wherein the carrier includes perpendicular connecting sections of the serpentine wire.

20. The seating unit defined in claim 15, wherein the carrier includes at least one sheet of material holding the resilient force-distributing members in a prearranged pattern.

21. The seating unit defined in claim 20, wherein the at least one sheet includes a sheet of fabric material, with the resilient force-distributing members being energy members that are coupled to the sheet in a parallel pattern.

22. The seating unit defined in claim 1, wherein the resilient force-distributing members are parallel spaced-apart linear components.

23. The seating unit defined in claim 1, wherein the frame comprises a perimeter frame that includes front and rear frame members and that further includes opposing side frame members interconnecting front and rear ends of the front and rear frame members, the opposing side frame members each including one of the at least one vertical side sections.

24. The seating unit defined in claim 1, wherein the at least one vertical side section includes opposite sections with pockets therein, and wherein the force-distributing members include L-shaped ends that slidably engage the pockets for sliding movement upon flexure of the force-distributing members.

25. The seating unit defined in claim 1, wherein the at least one vertical side section includes opposite sections, and wherein the force-distributing members include ends that operably slidably engage opposite sections of the frame and further include S-shaped bends and straight sections that extend between the S-shaped bends, the straight sections being located at elevated positions relative to a top surface of the opposite sections of the frame.

26. The seating unit defined in claim 1, wherein the at least one vertical side section includes a pair of side frame members each having a plurality of recesses that are shaped to slidingly receive the ends of the plurality of force-distributing members, and an abutting surface being an end surface within the recesses.

27. The seating unit defined in claim 26, wherein the side frame members includes an angled surface inboard of each of the recesses for engaging and limiting flexure of the plurality of resilient force-distributing members.

28. The seating unit defined in claim 26, including a cover attached to the frame and covering the recesses to capture the ends of the plurality of resilient force-distributing members therein.

29. The seating unit defined in claim 26, wherein the ends of each of the resilient force-distributing members include L-shaped ends shaped to slidably matably engage individual ones of the recesses.

30. The seating unit defined in claim 26, wherein the recesses each define an opening facing in an inboard direction, the openings being smaller than the recesses and being configured to receive individual ones of the plurality of resilient force-distributing members.

31. A seating unit comprising:

a back frame having at least one vertical side section forming a rearwardly concave shape in a lumbar region;

a flexible supporting surface supported by the frame;

a plurality of elongated resilient force-distributing members associated with said supporting surface to control a contour of the supporting surface when supporting a seated user, the resilient force-distributing members being generally flexible and bendable along their length and being sufficient in number and distribution across the supporting surface so as to reduce localized deflection of the supporting surface and thereby reduce point contact pressure associated with the seated user; and

a tensioning component associated with the lumbar section of the back frame that resiliently bends and thus pretensions at least some of the resilient force-distributing members, wherein the at least one vertical side section includes a pair of spaced apart side frame members each with a plurality of recesses formed therein, the tensioning component being formed by an abutting surface on each of the side frame members that abuts an end of the plurality of force-distributing members to cause bending and hence pretensioning of some of the resilient force-distributing members, wherein the resilient force-distributing members have a round cross section.

32. A seating unit comprising:

a back frame having at least one vertical side section forming a rearwardly concave shape in a lumbar region;

a flexible supporting surface supported by the frame;

a plurality of elongated resilient force-distributing members associated with said supporting surface to control a contour of the supporting surface when supporting a seated user, the resilient force-distributing members being generally flexible and bendable along their length and being sufficient in number and distribution across the supporting surface so as to reduce localized deflection of the supporting surface and thereby reduce point contact pressure associated with the seated user; and

a tensioning component associated with the lumbar section of the back frame that resiliently bends and thus pretensions at least some of the resilient force-distributing members, wherein the at least one vertical side section includes a pair of spaced apart side frame members each with a plurality of recesses formed therein, the tensioning component being formed by an abutting surface on each of the side frame members that abuts an end of the plurality of force-distributing members to cause bending and hence pretensioning of some of the resilient force-distributing members, wherein the resilient force-distributing members are resiliently stiff steel rods.

33. A seating unit comprising:

a frame having opposing side frame members defining a space therebetween;

resilient support means adapted to bend and flex for supporting a seated user with distributed support forces even when the seated user generates point loads, the resilient support means having opposing ends that are supported by the frame and having sufficient resilient stiffness to support a seated user when the opposing ends of the force-distributing members are vertically supported; and

decoupling means for operably supporting the resilient support means on the frame, the decoupling means combining with the frame to provide support to the opposing ends but allowing the opposing ends to move inwardly relative to the opposing side frame members without undesirably forcibly drawing the opposing frame members inwardly when the resilient support means are bent and flexed, the resilient support means including elongated resilient force-distributing members, wherein the decoupling means includes at least one recess that movably support ends of the plurality of resilient force-distributing members on the opposing spaced-apart side frame members for inward movement upon the seated user sitting on the seating unit and further includes surfaces inboard of the recesses for providing additional support to the resilient support means when the resilient force-distributing members are flexed to a predetermined maximum flexed condition.

34. The seating unit defined in claim 33, wherein resilient force-distributing members are generally bendable along their length when flexed, the plurality of resilient force-distributing members being sufficient in number and distribution about the supporting surface so as to substantially reduce localized point deflection of the supporting surface and thereby reduce point pressure contact associated with the seated user.

35. The seating unit defined in claim 33, wherein the decoupling means slidably supports the ends of the plurality of resilient force-distributing members on the opposing spaced-apart side frame members.

36. The seating unit defined in claim 33 wherein the decoupling means slidably supports the ends of the plurality of resilient force-distributing members on the opposing spaced-apart side frame members, the decoupling means including stretchable elastic material supporting the ends of the resilient force-distributing members.

37. The seating unit defined in claim 33, wherein the frame is a back perimeter frame defining an opening over which the resilient force-distributing members are positioned.

38. The seating unit defined in claim 33, including a wire strand forming at least two adjacent ones of the resilient force-distributing members and an intermediate section interconnecting the at least two adjacent resilient force-distributing members.

39. The seating unit defined in claim 33, wherein the resilient force-distributing members have a round cross section.

40. The seating unit defined in claim 33, including end pieces attached to the ends of each of the resilient force-distributing members, the end pieces being separate molded components and configured to movably support the ends of the resilient force-distributing members.

41. The seating unit defined in claim 33, wherein the decoupling means includes a carrier for supporting the ends of the resilient force-distributing members.

42. The seating unit defined in claim 41, wherein the carrier includes a pivot for rotatably supporting the opposing ends on the support.

43. The seating unit defined in claim 42, wherein the pivot is formed integral with the resilient force-distributing members.

44. The seating unit defined in claim 42, wherein the pivot includes a downwardly shaped leg on each of the opposing ends of the resilient force-distributing members.

45. The seating unit defined in claim 42, wherein the pivot includes a plurality of separate components each engaging one of the ends of the resilient force-distributing members.

46. The seating unit defined in claim 42, wherein the pivot includes a plurality of molded-on parts attached to the resilient force-distributing members.

47. The seating unit defined in claim 42, wherein the pivot is integrally molded with the side frame members.

48. The seating unit defined in claim 42, wherein the pivot is between 1-3 inches below a top surface of resilient force-distributing members.

49. The seating unit defined in claim 42, wherein the individual resilient force-distributing members and pivots are separate components interconnected by an elongated connector.

50. The seating unit defined in claim 41, wherein the side frame members include innermost surfaces that are located outboard of the ends of resilient force-distributing members.

51. The seating unit defined in claim 41, including bearings on at least some of the ends of resilient force-distributing members.

52. The seating unit defined in claim 51, wherein the bearings include a plurality of bearing shoes.

53. The seating unit defined in claim 52, wherein the bearing shoes are made of acetal.

54. The seating unit defined in claim 41, wherein the carrier is constructed to deform and absorb at least some of the forces caused by inward movement of ends of resilient force-distributing members.

55. The seating unit defined in claim 54, wherein the carrier includes a resilient block of stretchable material.

56. The seating unit defined in claim 41, wherein the carrier includes a sheet of material with the resilient force-distributing members being attached to the sheet to retain a location of resilient force-distributing members.

57. The seating unit defined in claim 41, wherein the carrier includes a plurality of structural members, one being attached to each end of each one of the resilient force-distributing members, and the carrier further includes an interconnecting elongated member that runs parallel the side frame members and perpendicular a length direction defined by the resilient force-distributing members for interconnecting all adjacent ones of the structural member.

58. The seating unit defined in claim 41, wherein the resilient force-distributing members are transverse sections of a continuous serpentine wire and wherein the carrier includes perpendicular connecting sections of the continuous serpentine wire.

59. The seating unit defined in claim 41, wherein the carrier includes at least one sheet of material holding the resilient force-distributing members in a predetermined position.

60. The seating unit defined in claim 59, wherein the carrier includes a sheet of fabric material, with the resilient force-distributing members being energy members that are coupled to the sheet in desired locations.

61. The seating unit defined in claim 41, wherein the resilient force-distributing members are linear.

62. The seating unit defined in claim 41, wherein the resilient force-distributing members are resiliently stiff rods.

63. The seating unit defined in claim 41, wherein the frame is a perimeter frame, with front and rear frame members connecting front and rear ends of the frame members.

64. The seating unit defined in claim 41, wherein the carrier supports the plurality of resilient force-distributing members on the side frame members and being configured to stretch and compensate in a direction generally parallel the resilient force-distributing members so that when the resilient force-distributing members are flexed and bent, inward movement of the opposing ends is accommodated at least in part by the carrier.

65. The seating unit defined in claim 41, wherein the resilient force-distributing members each have a bending strength and an unstressed shape, and have a memory to return to the unstressed shape when bending stress is removed therefrom;

and wherein the decoupling means is a strip of material having edges coupled to the side frame members and carrying the resilient force-distributing members.

66. The seating unit defined in claim 41, wherein the decoupling means is a sheet of material adapted to provide support to a seated user, the sheet material defining a plane including a first direction and a perpendicular second direction, and including a plurality of elongated resiliently bendable resilient force-distributing members coupled to the sheet and oriented in the second direction, the sheet material being bendable about second lines parallel the second direction with the resilient force-distributing members distributing point loads into distributed areas that are elongated in the second direction.

67. The seating unit defined in claim 41, wherein the resilient force-distributing members include opposing ends that terminate short of and are located inboard of the opposing edges.

68. The seating unit defined in claim 33, wherein the frame comprises a back frame having a forwardly-protruding lumbar region.

69. The seating unit defined in claim 68, including a tensioning component shaped to engage, bend, and hence pretension several of the resilient force-distributing members in the lumbar region.

70. The seating unit defined in claim 33, including at least one cover attached to and covering the side frame members, the side frame members including recesses operably supporting the ends of the resilient force-distributing members with the at least one cover closing the recesses except for a plurality of inboard openings through which the plurality of resilient force-distributing members extend.

71. The seating unit defined in claim 70, wherein the inboard openings are smaller than the recesses and wherein the ends of the plurality of resilient force-distributing members are larger than the openings.

72. The seating unit defined in claim 71, wherein the ends of the resilient force-distributing members are L-shaped and positioned to slide within the recesses.

73. A comfort surface for a seating unit comprising:

a flexible supporting surface;

a frame with side frame members defining a plurality of recesses with openings that open in an inboard direction and that are smaller than the recesses; and

a plurality of elongated resilient force-distributing members having sufficient resilient stiffness to support a seated user, the force-distributing members including opposing ends movably supported by the side frame members for inward movement when the force-distributing members are bent from the seated user'"'"'s weight, the force-distributing members being associated with said supporting surface to control the contour of the supporting surface when supporting the seated user, the resilient force-distributing members being generally bendable along their length and being sufficient in number and distribution across the supporting surface so as to reduce localized deflection of the supporting surface and thereby reduce point contact pressure associated with the seated user, the opposing ends of the force-distributing members having bent end portions that extend laterally to restrict movement of the bent end portion through the openings but that permit sliding within the recesses, including spaced-apart side frame members defining a seating area therebetween, the side frame members defining the recesses, and wherein the plurality of resilient force distributing members are positioned with the opposing ends operably supported on the side frame members, including at least one tensioning component that engages and resiliently bends at least some of the force-distributing members to a more curved pretensioned shape.

74. The comfort surface defined in claim 73, including a back frame incorporating the side frame members, the side frame members having a lumbar region with a forwardly-protruding shape.

75. The comfort surface defined in claim 73, including flex-limiting surfaces on the side frame members that engage the resilient force-distributing members when flexed a predetermined amount to limit maximum flexure of at least some of the resilient force-distributing members.

76. A comfort surface for a seating unit comprising:

a flexible supporting surface;

a frame with side frame members defining a plurality of recesses with openings that open in an inboard direction and that are smaller than the recesses; and

a plurality of elongated resilient force-distributing members having sufficient resilient stiffness to support a seated user;

the force-distributing members including opposing ends movably supported by the side frame members for inward movement when the force-distributing members are bent from the seated user'"'"'s weight, the force-distributing members being associated with said supporting surface to control the contour of the supporting surface when supporting the seated user, the resilient force-distributing members being generally bendable along their length and being sufficient in number and distribution across the supporting surface so as to reduce localized deflection of the supporting surface and thereby reduce point contact pressure associated with the seated user, the force-distributing members having bent end portions that extend laterally to restrict movement of the bent end portion through the openings but that permit sliding within the recesses, including spaced-apart side frame members defining a seating area therebetween, the side frame members defining the recesses, and wherein the plurality of resilient force distributing members are positioned with the opposing ends operably supported on the side frame members, including flex-limiting surfaces on the side frame members that allow some movement in a direction parallel a length of the elongated resilient force distributing members but that engage the opposing ends of the resilient force-distributing members when flexed a predetermined amount to limit maximum flexure of at least some of the resilient force-distributing members, wherein the recesses in the side frame members are configured to matably slidingly engage ends of the resilient force-distributing members, the flex-limiting surfaces being at an inboard end of the recesses.

77. The comfort surface defined in claim 76, wherein the side frame members include angled surfaces inboard of the recesses that form the flex-limiting surfaces.

78. A comfort surface for a seating unit comprising:

a flexible supporting surface;

a frame including side frame members defining a plurality of recesses with openings that open in an inboard direction and that are smaller than the recesses; and

a plurality of elongated resilient force-distributing members having sufficient resilient stiffness to support a seated user;

the force-distributing members including opposing ends movably supported by the side frame members for inward movement when the force-distributing members are bent from the seated user'"'"'s weight, the force-distributing members being associated with said supporting surface to control the contour of the supporting surface when supporting the seated user, the resilient force-distributing members being generally bendable along their length and being sufficient in number and distribution across the supporting surface so as to reduce localized deflection of the supporting surface and thereby reduce point contact pressure associated with the seated user, the force-distributing members having bent end portions that extend laterally to restrict movement of the bent end portion through the openings but that permit sliding within the recesses, including spaced-apart side frame members defining a seating area therebetween, the side frame members defining the recesses, and wherein the plurality of resilient force distributing members are positioned with the opposing ends operably supported on the side frame members, including a cover attached to the side frame members and covering the recesses.

79. The comfort surface defined in claim 78, wherein the opposing ends of the resilient force-distributing members include configured ends captured non-releasably in the recesses by the cover.

80. The comfort surface defined in claim 78, wherein the side frame members and the cover combine to define an opening facing inwardly from each of the recesses, the opening being smaller than the recesses, the ends of the resilient force-distributing members being enlarged and configured to be larger than individual ones of the openings such that the ends cannot move through the openings.

81. The comfort surface defined in claim 80, wherein the ends of the resilient force-distributing members are L-shaped and configured to slide within the recesses.

82. A seating unit comprising:

a back frame having a pair of vertical side sections defining a lumbar region forming a forwardly protruding shape;

a flexible supporting surface supported by the frame; and

a plurality of elongated resilient force-distributing members supported by the frame and having sufficient resilient stiffness to support a seated user when opposing ends of the force-distributing members are supported for inward movement when the force-distributing members are bent to support a weight, the force-distributing members being associated with and supporting said supporting surface to control a contour of the supporting surface when supporting a seated user, the resilient force-distributing members being generally flexible and bendable along their length and being sufficient in number and distribution across the supporting surface so as to reduce localized deflection of the supporting surface and thereby reduce point contact pressure associated with the seated user;

several of the resilient force-distributing members being resiliently bent and having their opposing ends positioned closer together than other opposing ends such that the several force-distributing members are thus pretensioned to a more curved pretensioned shape different than a remaining number of the resilient force-distributing members, and further having at least one end slidably supported on the side sections to minimize inward pull and stress on the side sections when the seated user is sitting thereon.