Reclinable Chair

• US 20020043843A1
• Filed: 09/17/2001
• Published: 04/18/2002
• Est. Priority Date: 09/28/2000
• Status: Active Grant

• Current Assignee: Formway Furniture Limited
• Original Assignee: Formway Furniture Limited
• Inventors: Pennington, Mark Rundle, Stewart, Robert Bruce, Fifield, Jon Leonard
• Granted Patent: US 6,817,667 B2
• Time in Patent Office: Days
• US Class Current: 297/301.1
• 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 1/03 the parts being arm-rests conversion into a bed A47C17/12
• CPC Class Codes: A47C 1/0307 adjustable rectilinearly in horizontal direction
• CPC Class Codes: A47C 1/031 having coupled concurrently adjustable supporting parts
• CPC Class Codes: A47C 1/03205 having adjustable and lockable inclination
• CPC Class Codes: A47C 1/03255 with a central column, e.g. rocking office chairs
• CPC Class Codes: A47C 31/126 for chairs
• CPC Class Codes: A47C 7/004 for chairs or stools with central column, e.g. office chairs
• CPC Class Codes: A47C 7/006 with castors
• CPC Class Codes: A47C 7/029 of non-adjustable shape adapted to a user contour or ergonomic seating positions
• CPC Class Codes: A47C 7/22 Straps or the like for direct user support or for carrying upholstery
• CPC Class Codes: A47C 7/282 with mesh-like supports, e.g. elastomeric membranes
• CPC Class Codes: A47C 7/46 with special, e.g. adjustable , lumbar region support profile; "Ackerblom" profile chairs
• CPC Class Codes: A47C 7/462 adjustable by mechanical means

Abstract

A chair (10) includes a supporting frame (20,22) and a seat portion (14) which is foldable about a transverse fold to define a rearward portion behind the transverse fold and a forward portion, forward of the transverse fold. The seat portion (14) is supported above the supporting frame by its rearward portion. The chair (10) also includes a reclinable back portion (16) and a recline mechanism with which the back portion (16) is connected for reclining action of the back portion (16). The recline mechanism is operably linked to the rearward portion of the seat portion (14) such that on reclining action of the back portion (16), the rearward portion is moved to increase in rearward tilt angle and to obtain a net increase in height above the supporting frame (20,22), with a consequent folding of the seat portion about the transverse fold line under the weight (W) of the occupant.

Claims

1. A chair comprising:

a supporting frame;

a seat portion which is foldable about a transverse fold to define a rearward portion behind the transverse fold and a forward portion, forward of the transverse fold, the seat portion being supported above the supporting frame by its rearward portion;

a reclinable back portion; and

a recline mechanism with which the back portion is connected for reclining action of the back portion, the recline mechanism being operably linked to the rearward portion of the seat portion such that on reclining action of the back portion, the rearward portion is moved to obtain a net increase in height above the supporting frame, with a consequent folding of the seat portion about the transverse fold line under the weight of the occupant.

2. The chair as claimed in claim 1 wherein the recline mechanism is operably linked to the rearward portion of the seat portion such that on reclining action of the back portion, in addition to obtaining a net increase in height above the supporting frame, the rearward portion is moved to increase in rearward tilt angle.

3. The chair as claimed in claim 1 wherein the seat portion is constructed of a resiliently flexible material.

4. The chair as claimed in claim 3 wherein the seat portion comprises a panel which has apertures to enhance its flexibility.

5. The chair as claimed in claim 1 wherein the seat portion takes the form of a panel and stiffening webs are provided which offer resistance to folding towards the rear of the seat portion and lesser amount of resistance to flexing towards the forward edge of the seat portion.

6. The chair as claimed in claim 5 wherein the stiffening webs are tapered to offer the progressively increasing resistance to folding from the front edge of the seat portion towards the rear.

7. The chair as claimed in claim 1 wherein the rearward portion of the seat portion is supported, at least in part, by the recline mechanism and the forward portion is substantially unsupported.

8. The chair as claimed in claim 1 wherein the recline mechanism comprises a four bar linkage comprising four elements as follows:

a main support forming part of the supporting frame;

a second linkage comprising the seat portion or a guide relative to which the seat portion is selectively movable;

a front support linkage extending between the main support and the second linkage; and

a drive linkage wherein the drive linkage is pivotable about a drive axis through the main support, the drive linkage being connected to the guide and being operably linked to be driven about the drive axis by rearward recline action of the back portion to bring about the net increase in height of the second linkage on rearward recline action of the back.

9. The chair as claimed in claim 8 wherein two such four bar linkages are defined on opposite sides of the chair.

10. The chair as claimed in claim 9 wherein the main support is selectively height adjustable.

11. The chair as claimed in claim 1 wherein the seat portion is adjustable in position between a forward extended position and a rearward retracted position such that the positioning of the transverse fold is variable as a function of the seat depth position.

12. The chair as claimed in claim 11 wherein the recline mechanism includes at least one guide and the seat portion is slidable relative to the guide between the extended and retracted positions, the guide including a fixed portion about which the seat portion folds.

13. The chair as claimed in claim 12 wherein the guide has an upper surface having a forward portion with an upwardly facing convex shape whereby a transition in curvature defines the transverse fold position of the seat portion.

14. The chair as claimed in claim 12 wherein the recline mechanism comprises a four bar linkage comprising four elements as follows:

a main support forming part of the supporting frame;

the guide;

a front support linkage extending between the main support and the guide; and

a drive linkage wherein the drive linkage is pivotable about a drive axis through the main support, the drive linkage being connected to the guide and being operably linked to be driven about the drive axis by rearward recline action of the back portion to bring about the net increase in height of the guide on rearward recline action of the back.

15. The chair as claimed in claim 14 wherein two such four bar linkages are defined on opposite sides of the chair.

16. The chair as claimed in claim 15 wherein the back portion is pivotally connected to the main support at a recline axis.

17. The chair as claimed in claim 16 wherein the recline axis is located below the seat portion.

18. The chair as claimed in claim 17 wherein the recline axis is located below the ischial protuberosities of the chair occupant.

19. The chair as claimed in claim 14 wherein the back portion is biased against reclining by a recline biasing device.

20. The chair as claimed in claim 19 wherein the recline biasing device comprises one or more springs.

21. The chair as claimed in claim 20 wherein two back extension arms substantially rigidly extend from the back portion and pivotally connect the back portion to the main support, the one or more springs being held by one or both of the back extension arms, with the spring(s) acting against the main support.

22. The chair as claimed in claim 21 wherein the biasing force of the recline biasing device is adjustable.

23. The chair as claimed in claim 22 wherein two springs are provided, being a first spring and a second spring, both of which operate in the manner of leaf springs with the second spring being clampable against the first spring with the combination having a resultant spring rate, with the degree of clamping being variable to adjust the resultant spring rate.

24. The chair as claimed in claim 1 wherein the back portion comprises a flexible frame which is flexible or at least flexible at a part corresponding to the lumbar region of the occupant.

25. The chair as claimed in claim 24 wherein the flexibility of the back portion is adjustable.

26. The chair as claimed in claim 25 wherein the flexibility adjustment takes place automatically in response to the weight imparted by the occupant on the seat portion with, at least beyond a predetermined threshold in weight, the larger the weight, the greater the stiffness imparted to the back portion.

27. The chair as claimed in claim 26 wherein the flexibility adjustment takes place through the use of a tensionable biasing device comprising at least one leaf-type spring lying against the back portion at a lower region thereof.

28. The chair as claimed in claim 27 wherein the recline mechanism comprises a four bar linkage comprising four elements as follows:

a main support forming part of the supporting frame;

a second linkage comprising the seat portion or a guide relative to which the seat portion is selectively movable;

a front support linkage extending between the main support and the second linkage; and

a drive linkage wherein the drive linkage is pivotable about a drive axis through the main support, the drive linkage being connected to the second linkage and being operably linked to be driven about the drive axis by rearward recline action of the back portion to bring about a net increase in height of the second linkage on rearward recline action of the back; and

further wherein an interconnecting linkage interconnects the leaf-type spring with the drive linkage such that, at least beyond the predetermined threshold, the weight on the seat causes the leaf-type spring to flex against the back portion to impart greater stiffness thereto.

29. The chair as claimed in claim 28 wherein a supplementary spring is provided, whereby weight on the seat portion up to the predetermined threshold causes flexing of the supplementary spring.

30. The chair as claimed in claim 28 wherein two four bar linkages are defined on opposite sides of the chair, there being two such leaf-type springs on opposite sides of the chair with two such interconnecting linkages, wherein each interconnecting linkage is disposed directly between the associated leaf-type spring and the associated drive link.

31. The chair as claimed in claim 28 wherein a tension limit is provided to prevent over-tensioning of the tensionable biasing device.

32. A chair comprising:

a supporting frame;

a seat portion supported above the supporting frame; and

a back portion having a flexible portion, wherein the flexibility of the flexible portion is adjustable as a function of the weight of an occupant on the seat portion.

33. The chair as claimed in claim 32 wherein the flexible portion of the back portion corresponds to the lumbar region of an adult occupant of the chair.

34. The chair as claimed in claim 33 wherein the back portion comprises a flexible frame and other portions of the frame beyond the portion corresponding to the lumbar region are flexible.

35. The chair as claimed in claim 32 wherein the flexibility adjustment takes place automatically in response to the weight imparted by the occupant on the seat portion with, at least beyond a predetermined threshold in weight, the larger the weight, the greater the stiffness imparted to the back portion.

36. The chair as claimed in claim 35 wherein the flexibility adjustment takes place through the use of a tensionable biasing device interconnected with the seat portion, the seat portion being moveable on the application of weight from an occupant whereby the weight of the occupant acts through the interconnection to adjust the tensionable biasing device as a function of the weight of the occupant.

37. The chair as claimed in claim 36 wherein the tensionable biasing device comprises at least one leaf-type spring lying against the back portion at a lower region thereof.

38. The chair as claimed in claim 37 further including a recline mechanism embodying a four bar linkage comprising four elements as follows:

a main support forming part of the supporting frame;

a second linkage comprising the seat portion or a guide relative to which the seat portion is selectively movable;

a front support linkage extending between the main support and the second linkage; and

a drive linkage wherein the drive linkage is pivotable about a drive axis through the main support, the drive linkage being connected to the second linkage; and

further wherein an interconnecting linkage interconnects the leaf-type spring with the drive linkage such that, at least beyond the predetermined threshold, the weight on the seat causes the leaf-type spring to flex against the back portion to impart greater stiffness thereto.

39. The chair as claimed in claim 38 wherein a supplementary spring is provided, whereby weight on the seat portion up to the predetermined threshold causes flexing of the supplementary spring.

40. The chair as claimed in claim 38 wherein two four bar linkages are defined on opposite sides of the chair, there being two such leaf-type springs on opposite sides of the chair with two such interconnecting linkages, wherein each interconnecting linkage is disposed directly between the associated leaf-type spring and the associated drive link.

41. The chair as claimed in claim 40 wherein the four bar linkages tilt the seat portion synchronously with back recline.

42. The chair as claimed in claim 36 wherein a tension limit is provided to prevent over-tensioning of the tensionable biasing device.

43. The chair as claimed in claim 42 wherein the tension limit is in the form of a physical stop which acts against the leaf-type spring.

44. A chair comprising:

a supporting frame;

a main support supported by the supporting frame;

a seat portion supported above the supporting frame;

a reclinable back portion operably connected with the main support for reclining action relative to the main support;

a first recline spring operably connected between the main support and the reclinable back portion for resisting reclining action of the back portion; and

a second recline spring operably connected between the main support and the reclinable back portion;

wherein the second recline spring is selectively adjustable to impart a varying amount of resistance to the reclining action of the back portion.

45. The chair as claimed in claim 44 wherein the resistance imparted by the second spring is adjustable between a nil amount and a predetermined amount.

46. The chair as claimed in claim 44 wherein the first recline spring comprises a leaf spring or spring bar.

47. The chair as claimed in claim 44 wherein the second recline spring comprises a leaf spring or spring bar.

48. The chair as claimed in claim 44 wherein a forward limit is provided to define the forward active position of the back portion whereby the first recline spring and selectively the second recline springs bias the back portion into the forward active position.

49. The chair as claimed in claim 44 further including an adjustment device wherein the adjustment device brings about adjustment of the length of the second recline spring.

50. The chair as claimed in claim 44 further including an adjustment device wherein the adjustment device brings about adjustment of the curvature of the second recline spring.

51. The chair as claimed in claim 50 wherein the adjustment device includes a cam having a cam surface bearing against the second spring, the position of the cam being moveable to adjust the curvature of the second spring.

52. The chair as claimed in claim 51 wherein the first and second springs lie against each other for at least a portion of the length of the springs and the cam is incorporated into a clamp to clamp the second recline spring against the first recline spring.

53. The chair as claimed in claim 44 wherein the main support is in the form of a transversely extending main transom and the back portion includes two spaced arms pivotally mounted to the main transom, the first recline spring extending between the two spaced arms and bearing against the main transom to bias the back portion against reclining action, the second recline spring extending substantially between the two spaced arms.

54. The chair as claimed in claim 44 wherein the back portion is also operably connected to the seat portion whereby the weight of the occupant assists to resist reclining action of the back portion.

55. A chair comprising:

a supporting frame;

a main support supported by the supporting frame;

a seat portion supported above the supporting frame;

a reclinable back portion operably connected with the main support for reclining action relative to the main support; and

a first recline spring comprising an elongate spring portion having dimensions of length, width and thickness wherein the width is greater than the thickness and further having a longitudinal axis aligned with the length of the elongate spring portion, the recline spring being operably connected between the main support and the reclinable back portion for resisting reclining action of the back portion through bending about an axis transverse to the longitudinal axis, wherein the first recline spring is rotatable about the longitudinal axis to adopt any one of a plurality of spring positions, at each of which the spring portion exhibits a differing spring rate in resistance to bending about the transverse axis.

56. The chair as claimed in claim 55 wherein the back portion is reclinable between a forward active position and a rear most position and a forward limit is provided to define the forward active position of the back portion and wherein the first recline spring is arranged such that as the main support and the back portion move relative to each other during recline action, each bears against the first recline spring, tending to flex the elongate spring portion about the transverse axis thereby biasing the back portion toward the forward active position through the inherent resistance of the spring.

57. The chair as claimed in claim 56 wherein, at the forward active position, no pretension is exerted on the first recline spring.

58. The chair as claimed in claim 56 wherein an intermediate portion of the first recline spring bears against the main support with an end portion of the first recline spring bearing against the back portion.

59. The chair as claimed in claim 56 wherein the ends of the first recline spring bear against the back portion with an intermediate part of the first recline spring bearing against the main support.

60. The chair as claimed in claim 59 wherein the main support comprises a transversely extending main transom and the back portion includes two spaced arms pivotally mounted to the main transom with the first recline spring extending alongside the main transom with the two ends of the first recline spring journaled in each arm and with an intermediate part of the first recline spring bearing against the main transom.

61. The chair as claimed in claim 60 wherein the main transom has a rearward extension.

62. The chair as claimed in claim 61 wherein the ends of the first recline spring are fitted with cylindrical bosses to be journaled in the arms of the back portion and the intermediate part has a cylindrical boss to bear against the main transom.

63. The chair as claimed in claim 62 wherein the main transom incorporates a bearer having a complementary bore or recess against which the cylindrical boss bears.

64. The chair as claimed in claim 63 wherein locators are provided to define each of the plurality of adoptable spring positions.

65. The chair as claimed in claim 64 wherein the locators comprise complementary projections and detents provided in one or more of the cylindrical bosses and the corresponding bearer.

66. The chair as claimed in claim 55 wherein the elongate spring portion of the first recline spring is in the form of a flat bar.

67. The chair as claimed in claim 66 wherein there are three spring positions, the first with the width dimension of the flat bar arranged substantially aligned with the transverse bending axis, a second adoptable spring position having the width dimension arranged diagonally to the transverse bending axis and a third with the width of the flat bar arranged transversely to the bending axis.

68. The chair as claimed in claim 55 wherein there is more than one elongate spring portion incorporated into the first recline spring.

69. The chair as claimed in claim 55 wherein the first recline spring includes an actuator for selective user rotation of the first recline spring.

70. The chair as claimed in claim 55 further including a second recline spring.

71. The chair as claimed in claim 70 wherein the second recline spring is adjustable.

72. The chair as claimed in claim 70 wherein the second recline spring is non-adjustable.

73. The chair as claimed in claim 72 wherein the second recline spring exhibits a preload when in a forward active position.

74. The chair as claimed in claim 55 wherein the back portion is operably connected to the seat portion whereby the weight of the occupant assists in resisting reclining action of the back portion.