Body support assembly and methods of use and assembly thereof

Abstract

A body support assembly includes a seat assembly and a backrest assembly supported by a roll control assembly. Methods of using and assembling the body support assembly are provided.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 947,911, filed December 13, 2019, entitled "Body Support Assembly and Methods for the Use and Assembly Thereof," and U.S. Provisional Patent Application No. 62 / 947,914, also filed December 13, 2019, entitled "Body Support Assembly and Methods for the Use and Assembly Thereof," and also claims priority to U.S. Patent Application No. 16 / 794,946, filed February 19, 2020, entitled "Body Support Assembly and Methods for the Use and Assembly Thereof," the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This application generally relates to body support components (e.g., chairs), and particularly to backrest components and / or seat components incorporated in the body support components, as well as various parts incorporated therein, together with methods of use and assembly thereof. Background Technology

[0004] Chairs, especially office chairs, may have a body support member configured with a suspension material (such as mesh fabric) stretched across the frame. This suspension material conforms to the user's body, providing micro-compliance and improved air circulation, along with accompanying cooling benefits. Typically, the frame must be rigid to maintain an appropriate level of tension in the suspension material. However, this rigidity can limit the flexibility of the body support member and introduce undesirable pressure points around the outer edges of the frame. Furthermore, the suspension material mounted on the chair seat typically needs to withstand high tension due to the load exerted on the seat by the seated user, which exacerbates the limited flexibility and rigidity of the support structure.

[0005] While a variety of mechanical systems, such as lumbar supports and roll control mechanisms, can be introduced to mitigate limited flexibility and provide additional adjustment capabilities, such systems are relatively expensive to manufacture, require additional maintenance, are prone to wear and tear over time, and can not be properly utilized by users due to the need for individual adjustment. Furthermore, such roll mechanisms typically include one or more rigid links and mechanical connections that are rigid and uncompliant, which results in greater rigidity and less forgiving seating, and which can result in a less desirable user experience. Conversely, systems that rely on the physical properties of the seat structure to introduce appropriate kinematics and flexibility can not be suitable for supporting suspension material. While the body support surface can be defined by one or more foam pads, foam material can limit air circulation and generally does not provide localized support. Furthermore, body support members configured with plastic shells, such as supported by a peripheral frame, generally do not provide a comfortable body-compliant support surface. SUMMARY

[0006] The present invention is defined by the following claims, no part of which should be considered limiting with respect to the claims.

[0007] In one aspect, one embodiment of a seat assembly includes a lower support platform having a first peripheral edge, an upper surface, and a lower surface. A support ring is coupled to and extends radially outward from the first peripheral edge of the lower support platform and defines a second peripheral edge. The support ring includes an upper surface. An upper shell is disposed above the upper surface of the lower support platform and the upper surface of the support ring and defines a recessed cavity. The upper shell has a third peripheral edge defining a central opening and an upper surface. Suspension material is secured to the upper shell across the central opening and covers the recessed cavity.

[0008] In another aspect, one embodiment of a body support member includes a load bearing frame having a body-facing first surface, a second surface opposite the first surface, a peripheral edge surface extending between the first surface and the second surface, and a peripheral slot formed in the peripheral edge surface and opening outward from the peripheral edge surface. A support frame includes a first surface and a peripheral edge. A flexible edge member is connected to the peripheral edge of the support frame. The flexible edge member has an inner surface spaced apart from and facing the peripheral edge surface of the load bearing frame. A gap is defined between the inner surface and the peripheral edge surface, wherein the gap is in communication with the peripheral slot. A textile material includes a peripheral edge. The textile material covers the first surface of the load bearing frame and is disposed in the gap between the inner surface of the flexible edge and the peripheral edge surface of the load bearing frame. The textile material engages at least a portion of the peripheral edge surface of the load bearing frame. The peripheral edge of the textile material is disposed in the peripheral slot.

[0009] In another aspect, one embodiment of a method of manufacturing a body support member includes disposing a perimeter edge of a textile material into a slot formed in a perimeter edge surface of a load bearing frame, covering at least a portion of the perimeter edge surface and a body-facing first surface of the load bearing frame with the textile material, and connecting a flexible edge member to the load bearing frame. The flexible edge member has an inner surface that is spaced apart from and faces the perimeter edge surface of the load bearing frame, wherein a gap is defined between the inner surface and the perimeter edge surface, wherein the gap is in communication with the perimeter slot, and wherein the textile material is disposed in the gap.

[0010] In another aspect, one embodiment of a seat assembly includes a lower support platform extending in a longitudinal direction. The lower support platform includes opposing side edges and a laterally extending first flex region extending between the opposing side edges that bifurcates the lower support platform into a front portion and a rear portion. The first flex region is bendable such that the rear portion is downwardly deflectable relative to the front portion, although in one embodiment both the front portion and the rear portion are upwardly movable during reclining. An upper shell includes opposing side members connected to the support platform by a pair of connectors. Each of the connectors includes a second flex region, wherein the second flex region is bendable such that the opposing side members are upwardly movable relative to the lower support platform when the rear portion is downwardly deflectable.

[0011] In another aspect, a body support member includes a load bearing frame having a central portion and a perimeter ring connected to the central portion by a plurality of connectors each having a flex region, wherein the perimeter ring defines a central opening. A resilient textile material is coupled to the perimeter ring across the central opening. A cushion is disposed between the central portion and the textile material. At least one of the plurality of connectors is deflectable inwardly from a first unloaded configuration to a first loaded configuration by a first amount in response to a load applied to the resilient material, and the resilient material is deflectable downwardly from a second unloaded configuration to a second loaded configuration by a second amount in response to the load applied thereto. When the first and second deflection amounts cause the resilient material to contact the cushion, the cushion engages the resilient material and provides supplemental support to the resilient material.

[0012] In another aspect, one embodiment of a body support member includes a flexible load bearing frame deformable from an unloaded configuration to a loaded configuration, a resilient textile material coupled to the load bearing frame, and a cushion disposed beneath the textile material. The flexible load bearing frame, the resilient material, and the cushion provide a first amount, a second amount, and a third amount of resilient support to a user engaged with and supported by the textile material.

[0013] In another aspect, one embodiment of a body support member includes a load bearing frame having opposing side portions defining an opening therebetween. A resilient textile material is coupled to the side portions across the opening with a cushion disposed beneath the textile material. At least one, and preferably both, of the side portions are deflectable inwardly from a first unloaded configuration to a first loaded configuration by a first amount in response to a load applied to the resilient material. The resilient material is deflectable downwardly from a second unloaded configuration to a second loaded configuration by a second amount in response to a load applied thereto, and when the first and second deflection amounts cause the resilient material to contact the cushion, the cushion engages the resilient material and provides supplemental support to the resilient material.

[0014] In another aspect, one embodiment of a body support assembly includes a base member, a lower support structure having a longitudinally extending portion coupled to the base member at a first location, a front link extending upwardly from the longitudinally extending portion forward of the first location, and a rear link extending upwardly from the longitudinally extending portion rearward of the first location. A back frame includes a first lower portion extending rearwardly from the rear link and an upright portion extending upwardly from the first lower portion. A seat support member is coupled to the front link and the rear link, wherein the seat support member supports a seating surface. A back support is pivotally connected to the upright portion at a second location above the seating surface and includes a second lower portion connected to the rear link below the seat support member.

[0015] In another aspect, one embodiment of a backrest assembly includes a base and a rigid back frame having a first upright portion and a first lower portion extending forwardly from the first upright portion and coupled to the base. The first lower portion is tiltable about a first flex region relative to the base. A flexible back support includes a second upright portion having a second flex region proximate a lumbar region of the back support, wherein the second upright portion is flexible about the second flex region, and a second lower portion extending forwardly from the second upright portion and coupled to the first lower portion. The second lower portion is tiltable about the first flex region relative to the first lower portion with the first lower portion. The second lower portion has a third flex region located between the first flex region and the second flex region, wherein the second lower portion is flexible about the third flex region, and wherein the second upright portion is pivotally coupled to the back frame at a third location spaced apart above the second flex location.

[0016] In another aspect, one embodiment of a body support assembly includes a base member and a lower support structure including a longitudinally extending portion coupled to the base member at a first location, the longitudinally extending portion defining a first flex region positioned rearward of the first location. A front link extends upward from the longitudinally extending portion forward of the first location, wherein at least one of the lower support member and the front link define a second flex region positioned forward of the first location. A rear link extends upward from the longitudinally extending portion rearward of the first location. A seat support member is coupled to the front link and the rear link, wherein the seat support member supports a seating surface. At least one of the seat support member and the front link define a third flex region, and the seat support member defines a fourth flex region adjacent the rear link. A rigid back frame extends upward and rearward from the lower support structure, wherein the rigid back frame is rigidly connected to the rear link. A flexible back support includes an upper portion pivotally connected to the rigid back frame at a second location vertically spaced above the seat support, and a lower portion rigidly connected to the rear link. The flexible back support has a fifth flex region between the seat support and the second location, and a sixth flex region between the fifth flex region and the rear link.

[0017] In another aspect, one embodiment of a backrest assembly includes a back frame including a pair of first uprights and a back support including a pair of second uprights, each of the second uprights positioned laterally outward of one of the first uprights. A body support member is coupled to the back support. A pair of links extend laterally between one of the first uprights and one of the second uprights, wherein each of the links includes a first link male portion extending laterally from the one of the first uprights and a second link male portion extending laterally from the one of the second uprights, wherein the first link male portion and the second link male portion overlap.

[0018] In another aspect, one embodiment of a backrest assembly includes a back frame having a first upright and a back support having a second upright laterally spaced from the first upright. A body support member is coupled to the back support. A link male portion extends laterally from one of the first upright or the second upright and includes a laterally extending, non-cylindrical insert portion received in a socket formed in the other of the first upright or the second upright. The insert portion is rotatable relative to the socket about a laterally extending axis between at least a first pivot position and a second pivot position, wherein the insert portion engages a first stop surface and a second stop surface of the socket when the insert portion is in the first position and the second position, respectively.

[0019] In another aspect, one embodiment of a support structure for a body support member includes a lower support member having a first column extending upwardly, a back frame having a second column extending upwardly, and a seat support having a downwardly extending boss structure coupled to the first column and the second column.

[0020] In another aspect, one embodiment of a body support assembly includes a seat having opposite sides spaced apart in a lateral direction and a front and a back spaced apart in a first longitudinal direction. A back support has opposite sides spaced apart in the lateral direction and a top and a bottom spaced apart in a second longitudinal direction. A support structure supports the seat at a pair of laterally spaced apart front locations and a central back location, where the back of the seat is rotatable about a first longitudinal axis relative to the front of the seat. The support structure supports the back support at a pair of laterally spaced apart upper locations and a central lower location, where the bottom of the back support is rotatable about a second longitudinal axis relative to the top of the back support. In one embodiment, the seat and the back support are coupled to a central back link at the central back location and the central lower location, respectively.

[0021] In another aspect, one embodiment of a body support assembly includes a body support member tiltable relative to a base. A tilt limiter assembly is engaged between the body support member and the base to limit tilting of the body support member relative to the base. The tilt limiter assembly includes a tilt limiter having at least two rotational degrees of freedom.

[0022] In another aspect, one embodiment of a body support assembly includes a body support member tiltable rearward relative to a base. The body support member has a front and a back spaced apart in a longitudinal direction. A tilt stop member includes a first end connected to the body support member and a second end defining a stop portion. A tilt limiter includes at least a first stop surface and a second stop surface spaced apart in the longitudinal direction, where the plurality of stop surfaces are angularly spaced apart about a longitudinal axis. The tilt limiter is rotatably mounted to the base about the longitudinal axis and is rotatable about the longitudinal axis between a first position in which the stop portion engages the first stop surface and a second position in which the stop portion engages the second stop surface.

[0023] In another aspect, one embodiment of a body support assembly includes a lower base and a seat support connected to the lower base with an extendable support column having an actuation button. A handle is rotatable about a first lateral axis. A drive gear is connected to the handle and rotatable about the first lateral axis from a non-engaged configuration to an engaged configuration. The drive gear includes a first plurality of teeth. A driven gear is rotatable about a second lateral axis spaced apart from the first lateral axis. The driven gear includes a second plurality of teeth, wherein the first plurality of teeth and the second plurality of teeth are not engaged when the drive gear is in the non-engaged position. The drive gear is rotatable to the engaged configuration, wherein the first plurality of teeth and the second plurality of teeth are engaged after the handle is rotated a first predetermined amount about the first lateral axis. The driven gear is rotated about the second lateral axis from a non-actuated position to an actuated position when the drive gear is in the engaged configuration. An actuator is coupled to the drive gear, wherein the actuator is rotatable into engagement with the actuation button when the driven gear is rotated to the actuated position.

[0024] In another aspect, one embodiment of a backrest assembly includes a back frame having first and second laterally spaced uprights defining a central opening therebetween. Each of the first and second uprights has an upper portion and a lower portion defining independent forward facing first and second convex curvatures. A cross member extends between and is coupled to the uprights at a junction between the upper and lower portions. A suspension material is connected to the first and second uprights and spans the central opening. The suspension material has a front surface and a rear surface, wherein at least opposing side portions of the suspension material have the forward facing first and second convex curvatures. A laterally extending brace is coupled to and extends between the rear surface of the suspension material and the cross member.

[0025] In another aspect, one embodiment of an armrest assembly for a seat unit includes an armrest support adapted to attach to the seat unit and including an upper support platform. An armrest pad is adapted to support a person's arm portion and includes laterally spaced and downwardly extending rim portions positioned along opposite sides of the armrest pad. A pair of swing arm portions each have a first end pivotally connected to the upper support platform at spaced apart first locations and a second end pivotally and slidably connected to the armrest pad at spaced apart second locations. The swing arm portions adjustably support the armrest pad for independent longitudinal, lateral, and rotational adjustments. At least one of the rim portions engages at least one of the swing arm portions to limit lateral movement of the armrest pad relative to an inboard and / or outboard side of the support platform.

[0026] Various methods of using and assembling the body support assembly and other components are also provided.

[0027] Various embodiments of body support assemblies and components and methods of their use and assembly provide significant advantages over other body support assemblies and methods. For example, but not by way of limitation, the structure allows for the integration of suspension material into the backrest and / or seat while maintaining the overall flexibility of those components. The structure and user interface provide a body support structure that adapts to the user's body and provides macro-compliance during use while also providing micro-compliance at the user interface and avoiding hard interfaces around its perimeter.

[0028] Further, the various linkages and flex regions provide a simple but robust structure that ensures proper fit for a variety of users without the need for complex mechanical mechanisms and adjustment interfaces. The body support assembly and its various flex regions and material compliance provide improved comfort and fit while reducing costs by reducing and / or eliminating the total number of parts, including various metal components, which can reduce manufacturing costs. Further, the compliant materials can reduce the overall weight of the smaller body support assembly and the shipping costs associated therewith. The body support assembly is uncomplicated, durable, visually appealing, and capable of having a long operational life. At the same time, the various components are ideally adapted to interface with the compliant seat structure, including, for example, but not by way of limitation, floating recline limiters that adapt the movement of the body support members relative to the base.

[0029] The armrests also provide significant advantages, where the rim of the padding limits the inboard and outboard movement such that the platform below remains shaded during lateral movement, thereby improving the aesthetics of the armrests.

[0030] The disclosed backrests also provide significant advantages, such as, but not by way of limitation, providing a single piece of suspension material to cover a frame having multiple independent convex curvatures. The brackets allow the suspension material to conform to the backrest while pulling the backrest back to provide a conforming shape and pleasing aesthetic appearance.

[0031] The above summary has been presented by way of introduction and is not intended to limit the scope of protection of the claims that follow. The various preferred embodiments, and other advantages, will be better appreciated and understood when considered in connection with the following detailed description, taken in conjunction with the accompanying drawings.

[0032] ILLUSTRATED DRAWINGS

[0033] FIG. 1 is a perspective view of one embodiment of a body support assembly.

[0034] FIG. 2 is a perspective view of one embodiment of a body support assembly. FIG. 1 is a right side view of the body support assembly shown, where the left side view is a mirror image thereof.

[0035] FIG. 3 is a perspective view of one embodiment of a body support assembly. FIG. 1Front view of the body support assembly shown.

[0036] FIG. 4 Is FIG. 1 Rear view of the body support assembly shown.

[0037] FIG. 5 Is FIG. 1 Bottom view of the body support assembly shown.

[0038] FIG. 6 Is FIG. 1 Top view of the body support assembly shown.

[0039] FIG. 7A , FIG. 7B And FIG. 7C Partial cutaway view of the body support member.

[0040] FIG. 8 Partial perspective view of the seat without showing the textile material in order to reveal the underlying components.

[0041] FIG. 9 Top view of one embodiment of the seat support structure without showing the textile material or the load bearing frame in order to reveal the underlying components.

[0042] FIG. 10 Bottom perspective view of one embodiment of the lower seat support platform.

[0043] FIG. 11 Is FIG. 10 Right side view of the support platform shown, where the left side view is a mirror image thereof.

[0044] FIG. 12 Is FIG. 10 Rear view of the support platform shown.

[0045] FIG. 13 Is FIG. 10 Top view of the support platform shown.

[0046] FIG. 14 Left side view of one embodiment of the support ring, where the right side view is a mirror image thereof.

[0047] FIG. 15 Is FIG. 14 Top view of the support ring shown.

[0048] FIG. 16 Side view of one embodiment of the upper seat shell.

[0049] FIG. 17 Is FIG. 16 Top view of the upper shell shown.

[0050] FIG. 18It is a schematic side view showing the bending of the seat assembly during tilting.

[0051] FIG. 19 This is a schematic front view showing the bending of the seat assembly during tilting.

[0052] FIG. 20 This is an exploded view of the seat assembly.

[0053] FIG. 21 This is a schematic diagram showing a four-bar linkage that supports the seat assembly.

[0054] FIG. 22 This is a rear perspective view of a second embodiment of the body support component.

[0055] FIG. 23 yes FIG. 22 The front perspective view of the body support components shown.

[0056] FIG. 24 yes FIG. 22 The front view of the body support component shown.

[0057] FIG. 25 yes FIG. 22 The right-side view of the body support assembly is shown, with the left-side view being its mirror image, except for the actuator controls.

[0058] FIG. 26 yes FIG. 22 Rear view of the body support components shown.

[0059] FIG. 27 yes FIG. 22 Top view of the body support components shown.

[0060] FIG. 28 yes FIG. 22 The bottom view of the body support structure shown.

[0061] FIG. 29 This is a front perspective view of a third embodiment of the body support component.

[0062] FIG. 30 yes FIG. 29 Rear perspective view of the body support components shown.

[0063] FIG. 31 yes FIG. 29 The right-side view of the body support components shown.

[0064] FIG. 32 yes FIG. 29 The front view of the body support component shown.

[0065] FIG. 33 yes FIG. 29A left side view of the body support assembly shown.

[0066] FIG. 34 A FIG. 29 A rear view of the body support assembly shown.

[0067] FIG. 35 A FIG. 29 A top view of the body support assembly shown.

[0068] FIG. 36 A FIG. 29 A bottom view of the body support assembly shown.

[0069] FIG. 37 A 38 A right side view and a left side view of a fourth embodiment of the body support assembly.

[0070] FIG. 39 A right side view of the back support.

[0071] FIG. 40 A FIG. 39 A perspective view of the back support shown.

[0072] FIG. 41 A FIG. 39 A top view of the back support shown.

[0073] FIG. 42 A FIG. 39 A bottom view of the back support shown.

[0074] FIG. 43 A FIG. 37 An enlarged partial side view of the body support assembly shown.

[0075] FIG. 44 A partial cross-sectional view of a front portion of the seat assembly.

[0076] FIG. 45 A partial cross-sectional view of a side portion of the seat assembly.

[0077] FIG. 46 A partial cross-sectional view of a top portion of the back support.

[0078] FIG. 47 A partial cross-sectional view of a side portion of the back support.

[0079] FIG. 48 A partial front view of a connection between the back frame and the back support.

[0080] FIG. 49 A partial front view of a connection between the back frame and the back support.

[0081] FIG. 50 It is along FIG. 48 A partial sectional view of the connection between the back frame and the back support, taken from line 50-50.

[0082] FIG. 51 This is an exploded view of the connection between the back frame and the back support.

[0083] FIG. 52 This is a partial side view of the back frame connector.

[0084] FIG. 53 It is a cross-sectional view of the transverse member and the support connected thereto, with the textile material in an assembled configuration.

[0085] FIG. 54 It is a cross-sectional view of the support frame and textile materials in a pre-assembled configuration.

[0086] FIG. 55 It is a flowchart showing the assembly of the seat components.

[0087] FIG. 56 It is a partial plan view of the textile material installed on the seat assembly and back support.

[0088] FIG. 57 This is a rear perspective view of the back support, with the waist section connected to it.

[0089] FIG. 58 yes FIG. 57 The front view of the back support and waist shown.

[0090] FIG. 59 This is a magnified front view of the back support and the waist connection.

[0091] FIG. 60 This is an exploded view of the handrail assembly.

[0092] FIG. 61 for FIG. 60 A partial longitudinal sectional view of the handrail assembly shown.

[0093] FIG. 62 for FIG. 60 A partial cross-sectional view of the handrail assembly shown.

[0094] FIG. 63 and FIG. 64 It shows FIG. 60 The maximum fore-and-aft adjustment of the armrest assembly shown.

[0095] FIG. 65 and FIG. 66 It shows FIG. 60 The maximum left and right adjustment of the armrest assembly shown.

[0096] FIG. 67 and FIG. 68 Maximum inward angle adjustment of the armrest at the maximum forward and rearward positions is shown.

[0097] FIG. 69 and FIG. 70 Maximum outward angle adjustment of the armrest at the maximum forward and rearward positions is shown.

[0098] FIG. 71 is a top view of the control assembly.

[0099] FIG. 72 is a cross-sectional view of a rotatable tilt limiter engaged by a linear rack.

[0100] FIG. 73A to FIG. 73C is an exploded partial view of the control assembly.

[0101] FIG. 74 is an end view of the back support link male portion.

[0102] FIG. 75 is an end view of the back frame link male portion.

[0103] FIG. 76 is a schematic cross-sectional view showing the rotational limiter between the back frame and the back support.

[0104] FIG. 77 is an exploded partial view of a roll control assembly having a tilt limiter, an energy riser, and a height adjustment controller.

[0105] FIG. 78 is a cross-sectional view of the roll control assembly, tilt limiter, energy riser, and height adjustment controller.

[0106] FIG. 79 is an end view of the tilt limiter and energy riser along line 79-79 of FIG. 78 is a cross-sectional view of the roll control assembly, tilt limiter, and energy riser taken along line 79-79 of

[0107] FIG. 80 is a perspective view of the tilt limiter, energy riser, and height adjustment control assembly.

[0108] FIG. 81 is an exploded view of the tilt limiter, energy riser, and height adjustment control assembly.

[0109] FIG. 82A to FIG. 82D are end views of the tilt limiter and energy riser in an untitled position, a mid-tilt / mid-lift position, a full-tilt / full-lift position, and a full-tilt / no-lift position, respectively.

[0110] FIG. 83A and FIG. 83Bare top and bottom perspective views of the rear link connector.

[0111] FIG. 84A to FIG. 84D are bottom, top, exploded, and enlarged sectional views showing the connection between the front link and the seat assembly.

[0112] FIG. 85 is a partial view of one embodiment of the support frame.

[0113] FIG. 86 is a partial cutaway view of the seat assembly.

[0114] FIG. 87A and FIG. 87B are views of the drive gear and driven gear shown in the disengaged and engaged positions, respectively.

[0115] FIG. 88 is a front perspective view of the support frame.

[0116] FIG. 89 is a rear perspective view of the support frame.

[0117] FIG. 90 is a partial front perspective view of an alternative embodiment of the support frame.

[0118] FIG. 91A and FIG. 91B are perspective views of an alternative embodiment of the armrest assembly.

[0119] FIG. 92 is a perspective view of an alternative embodiment of the support frame.

[0120] FIG. 93 is a bottom perspective view of the lower support structure.

[0121] FIG. 94 is a top perspective view of the lower support structure. FIG. 93

[0122] is a sectional view of the lower support structure taken along the corresponding line shown. FIG. 95A to FIG. 95E FIG. 94 is a front perspective view of the lumbar support.

[0123] FIG. 96 is a front perspective view of the lumbar support shown in

[0124] FIG. 97 FIG. 96 is a front perspective view of the lumbar support shown in

[0125] FIG. 98 is a perspective view of the lumbar support adapter.

[0126] FIG. 99A and FIG. 99B ​​Rear view of a chair having a lumbar support applied thereto in an upper position and a lower position, respectively.

[0127] FIG. 100 Partial perspective view of a backrest having a headrest applied thereto.

[0128] FIG. 101 is a partial side view of the backrest shown. FIG. 100

[0129] FIG. 102 is a partial side view of the backrest shown. FIG. 100 and FIG. 101 is an exploded view of the headrest assembly shown.

[0130] FIG. 103 is a partial cross-sectional view of the connection between the lower support and the back support.

[0131] FIG. 104 is an end view of the tilt limiter and the energy boost limiter.

[0132] FIG. 105 is a cross-sectional view of the roll control assembly, the tilt limiter, the energy booster, and the height adjustment controller.

[0133] FIG. 106A to FIG. 106D are end views of the tilt limiter and the energy booster in a no tilt position, a medium tilt / medium boost position, a full tilt / full boost position, and a full tilt / no boost position, respectively.

[0134] FIG. 107 is a top view of the strap configuration. DETAILED DESCRIPTION

[0135] ​It should be understood that the term "plurality" as used herein means two or more. The term "longitudinal" as used herein refers to or relates to a length or lengthwise direction 2, 2' such as from a bottom to a top of a backrest assembly 6 or vice versa, or from a front to a back of a seat assembly 8 or vice versa. The term "lateral" as used herein refers to being on, pointing in, or extending in a left-to-right direction 4 of a body support assembly 10, which in one embodiment is shown as an office chair including a backrest assembly 6 and a seat assembly 8. It should be understood that a body support assembly can be configured to support any structure of a body, including but not limited to automotive, aircraft, and mass transit seats, beds, home furnishings including sofas and chairs, and other similar and suitable structures. In one embodiment of the backrest assembly disclosed below, the lateral direction 4 corresponds to a horizontal direction and the longitudinal direction 2 corresponds to a vertical direction, while in one embodiment of the seat assembly, the longitudinal direction 2' corresponds to a horizontal direction. The lateral direction 4 can be referred to as an X direction, while the longitudinal directions 2, 2' are referred to as Y directions and the Z direction is orthogonal to the body support surfaces of both the backrest assembly 6 and the seat assembly 8.

[0136] The term "coupled" means connected, either directly or indirectly, to or interfacing with, such as the intermediate member, and is not restricted to an immovable or permanent connection, although immovable or permanent connections can be coupled. The terms "first," "second," and the like, as used herein do not imply these components are in any way superior, inferior, or second in importance, but are simply used as a nomenclature to distinguish the components. It should also be understood that the designation of "first" and "second" does not necessarily imply that the two components or values so designated are different, but rather that, for example, a first direction can be the same as a second direction, with each simply being applied to a different component. The terms "upper," "lower," "rear," "front," "front," "rear," "vertical," "horizontal," "right," "left," and variations or derivatives thereof (e.g., "inferior," "superior," "vertical," "horizontal," "right," "left," etc.) mean, as used herein, in reference to an example body support assembly 10 as shown in the chair of FIGS. 1-2, the orientation as viewed from the perspective of a user seated therein. FIG. 1 to FIG. 6 and FIG. 22 to FIG. 36 The term "lateral" means non-parallel. The term "outward" refers to a direction away from a central location, for example, the phrase "radially outward" refers to a feature that deviates from a central location (e.g., a mid or inner region of a seat or backrest) and is generally in the X Y plane defined by the lateral direction 4 and the longitudinal direction 2, 2'. It should be understood that a feature or component that faces or "extends outward" does not necessarily originate from the same central point, but rather generally extends outwardly and diverges from the exterior along a non-tangential vector. Conversely, the term "inward" refers to a direction that faces toward a central or inner location.

[0137] The term "textile material" refers to a flexible material made from a web of natural or man-made fibers (yarns, filaments, threads, etc.). The textile material can be formed by weaving, knitting, crocheting, knotting, felting, or braiding. The textile material can include various upholstery materials (which can be used to cover a foam cushion, for example) and / or suspension materials (which can be stretched or tensioned across an opening to support a user).

[0138] Body support assembly:

[0139] Referring to FIG. 1 to FIG. 6 , FIG. 22 to FIG. 36 and FIG. 77 , the body support assembly 10 is shown to include a roll control assembly 18 (also referred to as a lower support structure), a base structure 12, and a backrest assembly 6 and a seat assembly 8. In one embodiment, the base structure 12 includes a leg assembly 14 and a support column 16 coupled to and extending upwardly from the leg assembly. The roll control assembly 18 is supported by and coupled to a top portion of the support column 16. The leg assembly can alternatively be configured as a fixed structure, such as a four-legged base, a sled-like base, or other configuration. In one embodiment, the support column 16 can be height adjustable, including for example but not limited to a telescoping column having a pneumatic, hydraulic, or electromechanical actuator. The leg assembly 14 includes a plurality of support legs 22 extending radially outwardly from a hub 24 about the support column. An end of each support leg can be equipped with a caster, runner, or other floor connecting member 20.

[0140] Armrest assembly:

[0141] In FIG. 1 to FIG. 6 embodiments, a pair of armrest assemblies 26 are coupled to the roll control assembly 18. As further disclosed below, a variety of user interface controls 28 are provided to actuate and / or adjust the height of the seat, or to control the tension and / or return force of the roll control assembly 18, including for example an actuation lever pivotally coupled to the armrest assembly.

[0142] Referring to FIG. 22 to FIG. 36 , FIG. 91A and FIG. 91BAnother embodiment of the armrest assembly 300 is coupled to the base structure 12. The armrest assembly includes a base portion 302 disposed above the support column 16, particularly above the longitudinal extension of the lower support structure 18 or the base link 33, and positioned between the base structure and the seat assembly 6. A platform 402 supports a tilt control assembly 18, which includes a housing 422 having a hub 405 for receiving the support column 16. A cover 900 extends around the housing, with the base portion 302 disposed on top of the cover 900 and covering the housing 522. The base portion 302 is coupled to the platform by one or more fasteners (shown as bolts) that clamp the housing 422 and the lower portion 400 of the tilt control assembly 18 therebetween.

[0143] The base portion 302 includes a pair of laterally extending arms 304, which are arranged between the lower support structure 18 and the seat assembly 6, and extend laterally outward (with a vector along axis 4) and rearward (with a vector along axis 2') from the lower support structure 18 and the seat assembly 6, as shown. FIG. 28 As shown, the seat assembly 6 includes a seat support member 308, and a pair of laterally extending arms 304 defining an angle α relative to the lateral direction 4. The base includes an upwardly projecting curved or flared portion 423 that partially covers the rear portion of the housing 422. The armrest assembly further includes a pair of upright portions 306, as shown... FIG. 28 As shown, the paired upright portions 306 are connected to the laterally extending arms 304 and extend upward along the opposite sides of the seat assembly 6 and the seat support member 308. FIG. 28 As shown, when viewed from above, the combination of the paired laterally extending arms 304 has a V-shaped configuration, while as FIG. 24 and FIG. 26 As shown, the armrest assembly 300 has a U-shaped form when viewed from the front or rear of the body support assembly. The armrest assembly 300 is rotatably fixed relative to the base 12 about a transverse axis, but rotates together with the seat assembly 6 about a vertical axis 310 and moves vertically together with the support column 16. The armrest assembly 300 does not tilt together with the seat assembly and / or backrest assembly, which can move relative to the armrest assembly from an upright nominal position to one or more tilted positions. It should be understood that, for example, as... FIG. 37 and 38 As shown, the chair can be configured to have no armrests on either side. If the armrest assembly is omitted, then... FIG. 73A The cover 421 shown can be bolted to the platform 402 above the housing 422 and the cover 900.

[0144] Reference FIG. 22 , FIG. 24 ,FIG. 25 、 FIG. 60 to FIG. 70 and FIG. 91B The upright portion of the armrest assembly defines an armrest support that supports an upper arm section 312 having an upper support platform 314. A depressible actuation button 321 is provided to allow vertical movement of the upper arm section 312 relative to and within the upright portion 306. In an alternative embodiment shown in FIG. 91A the armrest is not height adjustable but has an upper arm section 323 that is flush with and coupled to the upright portion 306. A pair of stops 316, shown as protrusions or posts, extend upwardly from the support platform 314 adjacent opposite sides of the platform 314, with the outer stops 316 longitudinally displaced rearwardly relative to the inner stops such that the stops 316 are positioned diagonally along an axis 329 that forms an angle β relative to the longitudinal axis 317.

[0145] An armrest pad 318 is adapted to support a person's arm portion, the armrest pad 318 being coupled to the support platform. The armrest pad 318 has a base 320 having laterally spaced and downwardly extending rim portions 322 positioned along opposite sides of the armrest pad. In one embodiment, the rim portions 322 extend around the entire perimeter of the base 320. The base 320 is preferably configured as a plastic plate. A pair of swing arm sections 324, 326 are provided, each having a first end portion 328, 330 pivotally connected to the upper support platform by a pair of fasteners 332 configured as screws having a washer, the pair of fasteners 332 engaging openings at spaced apart first locations 334, 336. These locations are spaced apart along the longitudinal axis 317. The swing arm sections 324, 326 each have a second end portion 338, 340 pivotally and slidably connected to the armrest pad 318 by a pair of upwardly extending boss structures 342, 344 or studs having end portions engaged by fasteners 350, 352 at spaced apart second locations 346, 348 that are displaced relative to the first locations. When the armrest pad is in a nominal position as shown in FIG. 61 the second locations 342 are spaced forwardly of the first locations 334 and the second locations 348 are spaced rearwardly of the first locations 344. As explained further below, the swing arm sections 324, 326 adjustably support the armrest pad for independent longitudinal, lateral and rotational adjustment, meaning that the armrest pad can be moved along and / or transverse to the longitudinal axis 317 and rotated about an axis that is perpendicular to the plane defined thereby.

[0146] As FIG. 60 、 FIG. 61 、 FIG. 65 and FIG. 66As shown, at least one of the side edge portions 322 has an inboard surface 358, 360 that engages a side surface 354, 356 of at least one of the swing arm portions 324, 326 to limit inboard and outboard lateral movement of the armrest pad 18 relative to the support platform 314. The pad base 320 has a pair of longitudinally spaced apart and longitudinally extending slots 364, 366 through which the second end portions of the pair of swing arm portions and the boss structures 342, 344 are specifically arranged to pass through. The boss structures 342, 344 are pivotably and translatable / slidably connected along the slots 364, 366 relative to the pad base 320. As shown in FIG. 60 , FIG. 63 and FIG. 64 As shown, the boss structures 342, 344 bottom out at the ends of the slots 364, 366 to limit fore-aft travel of the armrest pad 318 relative to the support platform 314. The fasteners 350 have enlarged head portions that act as a pair of guides 351 that are coupled to the second end portions 338, 340 of the pair of swing arm portions and are arranged on the top of the pad base within the concave portions 365, 367 around the periphery of the slots 364, 366, where the guides 351 provide relative translation / sliding and rotation of the pad base 320 relative to the swing arm portions 324, 326.

[0147] The armrest pad includes a plate 368 (preferably a steel plate) having a longitudinal track 370 extending along the bottom of the plate 368 and formed by a raised portion of the plate. The track 370 defines a channel that overlies the fasteners 350, the channel being sized in width and depth to accommodate the fasteners 350 within the channel to allow slidable movement of the armrest pad 318 in the longitudinal direction 317 as the bosses 342, 344 move in the slots 364, 366 and the fasteners 350 move in the track 370. The plate 368 is coupled to the base 320 by a plurality of fasteners 391 (shown as six), with the fasteners 350 sandwiched between the base 320 and the plate 368 and movable in the concave portions 365, 367 and the track 370. The interaction between the rotatable swing arm portions 324, 326 and the slidable / translatable armrest pad 318 allows the armrest pad 318 to be moved to a plurality of different positions relative to the support platform 314. In particular, the armrest pad 318 is movable from a nominal position designated as armrest pad 318' to an infinite number of positions, including: (1) a maximum inward turning angle Θ (e.g., 31.5 degrees in one embodiment) at the rearward and forward positions, FIG. 67 and FIG. 68 ) (2) a maximum outward turning angle Θ (e.g., 31.5 degrees in one embodiment) at the rearward and forward positions, FIG. 69 and FIG. 70) has a maximum outward turning angle Φ (e.g., 31.9 degrees in one embodiment), (3) at nominal forward and rearward limits ( FIG. 63 and FIG. 64 ) has a total travel of 62.52 mm in the longitudinal direction (47.24 mm rearward and 15.28 mm forward), and (4) at lateral limits ( FIG. 65 and FIG. 66 ) has a total travel of 46 mm (25 mm outboard and 21 mm inboard). As shown in FIG. 60 and FIG. 67 to FIG. 70 , stops 316 engage stops 382, 384 formed on the peripheral edges of swing arm portions 324, 326 to limit the maximum inward and outward angular adjustment.

[0148] In operation, as shown in FIG. 63 , FIG. 64 and FIG. 67 to FIG. 70 , fasteners 350 or guides 351 are movably disposed in tracks 370 between plate 368 and base 320 so that plate 368 and base 320 are slidable relative to support platform 314. Foam pad 372 is disposed on top of plate 368. Cover 374 is disposed over foam pad and has a peripheral edge portion 376 that surrounds the foam pad and plate to secure foam pad 372 to plate 368 and complete the assembly of armrest pad 318. Lip 378 or inset portion extends laterally and radially inwardly from edge portion 376 and is disposed between plate 368 and pad base 320. In one embodiment, cover 374 is made of polyurethane material.

[0149] The downwardly extending rim 322 that acts as a stop to engage the sides 354, 356 of the swing arm portions to limit the amount of lateral travel prevents platform 314 and swing arm portions 324, 326 from being exposed to view during use. As shown in FIG. 65 and FIG. 66 , armrest pad 318 overlies and covers the upper surface of support platform 314 at the maximum lateral limits, and with reference to FIG. 63 to FIG. 70 , a small portion of the support platform is visible in the maximum pronation position at the forward and rearward positions as shown in FIG. 67 and FIG. 68 , and FIG. 69 the supination position, in addition to almost all positions of the armrest pad (including the lateral and forward and rearward maximum limits).

[0150] Roll Control Assembly:

[0151] With reference to FIG. 1 to FIG. 6 , FIG. 22 to FIG. 38 , FIG. 43 , FIG. 77 , FIG. 78 andFIG. 83A to FIG. 84D The back assembly 6 and seat assembly 8 are operatively coupled to a recline control assembly 18 or lower support structure, which controls their movement, for example, during reclining. One embodiment of a suitable recline control assembly is disclosed in U.S. Patent Application No. 9,826,839, entitled “Chair Assembly with Upholstery Covering,” the entire disclosure of which is incorporated herein by reference. The recline control assembly can include a plurality of rigid control links that are mechanically connected, for example, via pivot pins, to form a link assembly including, for example, a four-bar linkage.

[0152] In other embodiments, the recline control assembly includes integrally formed links 23, 25, 33 that are configured, for example, to have strategic deformable locations that allow for predetermined deformations and define “flex regions” (otherwise referred to as “flex joints”) or virtual pivot locations. Various configurations of links and flex regions can be configured as disclosed and shown in U.S. Patent Publication No. 2016 / 0296026 Al, entitled “Seating Arrangement,” and U.S. Patent Publication No. 2018 / 0352961, entitled “Seating Arrangement and Method of Construction,” the entire disclosures of which are incorporated herein by reference.

[0153] For example, the recline control assembly 318 can be configured as FIG. 21 and FIG. 43The illustrated four-bar mechanism has a base link 33 connected to the bottom or base of the base structure 12 at a first location, and front links 23 and rear links 25 connected between the base link and the seat assembly 8. The base link 33, front links 23 and rear links 25 define a lower support structure. For example, the front links 23 and rear links 25 can be pivotally or flexibly connected to the base link 33 at flex regions 29, 31, whether integrally formed or otherwise. The front links 23 and rear links 25 can also be pivotally or flexibly connected to the seat assembly 8 at flex regions 27, 53, with the portion 57 of the seat assembly extending between the flex regions 27, 53 defining links of the four-bar mechanism. As explained in greater detail below, the flex region 53 is formed in a portion of the support platform 30 of the seat assembly. The plurality of flex regions 27, 29, 31, 53 can be formed as living hinges, or thin flexible hinges made of the same material as the two more rigid blocks connected by the living hinge, so as to provide relative rotation or relative pivoting between the more rigid blocks by bending of the living hinge. It will be appreciated that in alternative embodiments, the links and bars of the mechanism can also be configured as rigid links and bars connected at fixed articulation points.

[0154] In one embodiment, and with reference to FIG. 37 , FIG. 38 , FIG. 43 , FIG. 78 and FIG. 93 to FIG. 95E , the roll control assembly 318 or lower support structure includes a longitudinally extending portion 400 that extends fore and aft along the longitudinal axis 2’ and defines the base link 33. The longitudinally extending portion 400 is supported by a platform 402, which is configured as a plate member having an opening at a first location 406 that receives a hub 405 of a housing 422. The hub is shaped to receive an upper end of the support column 16 that extends through the opening. As shown in FIG. 93 and FIG. 95B , the portion 400 has a concave shape 403 defined in a bottom thereof, with a thinner central portion 405 and thicker outer side portions 509, in which the platform 402 is disposed.

[0155] A pair of laterally spaced apart front links 23 extend upwardly and forwardly from the longitudinally extending portion 400 at a location 408 positioned forward of the first location 406. As shown in FIG. 24 , the front links 23 have a maximum lateral width (W1) defined by laterally spaced apart outer side edges thereof. The rear links 25 also extend upwardly and forwardly from the longitudinally extending portion 400, but at a location 410 positioned rearward of the first location 404. As shown in FIG. 42As shown, the rear link 25 has a maximum transverse width defined by its laterally spaced apart outer lateral surfaces that is approximately equal to the width (W3) of the lower support 226 of the back support 212.

[0156] The lower support structure, which can be referred to as a lower housing, has a longitudinally extending portion 400, the front link 23, and in one embodiment, a portion of the rear link 25, defines a unitary structure that in turn defines two or three unitary links (or portions thereof) of a four-bar mechanism. The lower support structure 400 has strategically positioned stretch substrates 1220, 1222 FIG. 107 As shown, the stretch substrates 1220, 1222 are made of, for example, glass reinforced tape to accommodate the bending and deformation of the structure at the flex regions 29, 31. Strategically located on the lower support structure are specific geometries that allow for predetermined deformations and define the flex regions 29, 31 (otherwise referred to as "flex joints") or virtual pivot locations. As FIG. 107 As shown, the stretch substrate 1222 has an "H" shape with elongated side portions having a greater longitudinal length than a central portion thereof. The "H" helps to ensure that the side portions can extend further along the curved transition portions. In one embodiment, as FIG. 107As shown, the substrates 1220, 1222 are coupled to the central link body 1224, and then the subassembly of the link body 1224 and the substrates 1220, 1222 are overmolded with an outer body to define the lower support structure 400, the front link 23, and the strut 407. The substrate 1220 is molded along the bottom portion of the front leg of the central link body, while the substrate 1222 is disposed on the top of the back leg of the link body, such that the substrates are properly positioned to experience tensile forces during chair recline and use. The method of manufacturing the reinforced support structure further includes positioning the strip carrier having the first and second sections 1220, 1222 of exposed fiberglass strips in a mold in a manner such that the first and second sections of the strips are spaced apart in different planes within the mold, and molding a shell over the strip carrier and the first and second sections of the strips, wherein the first section of the strips is positioned adjacent to an upper surface of the shell, and the second section of the strips is positioned adjacent to a lower surface of the shell. Various configurations of links and flex regions can be configured as shown and disclosed in U.S. Patent Publication No. 2016 / 0296026 Al entitled “Seating Arrangement” and U.S. Patent Publication No. 2018 / 0295996 Al entitled “Seating Arrangement,” the entire disclosures of which are incorporated herein by reference. The phrase “flex region” refers to a portion of the structure that allows for flexing or bending in a specified region through elastic deformation, thereby allowing or providing for relative flexing movement (e.g., pivoting or bending) of the component or structure on opposite sides of the flex region, thereby defining a virtual pivot location, e.g., a horizontal pivot axis, it being understood that the virtual pivot axis can move during the flexing, rather than being defined as a hard fixed axis.

[0157] As shown, for example, in FIG. 21 , FIG. 24 , FIG. 25 , FIG. 84A to FIG. 84D , FIG. 93 , FIG. 94 and FIG. 95D and FIG. 95E As shown, for example, in FIG. 95D and FIG. 95EAs shown, the inner edge of the blade can taper or be thinner, while the outer edge is curved. The front link has a generally "S" shape, with the upper end portion 414 defining a flange having a plurality of boss structures or insert portions extending upwardly from the flange. A flex region 27 can be formed in the front link, in the longitudinally extending portion 57, or at the junction between the front link 23 and the portion 57, or can be defined by any combination thereof. For example, in various embodiments, the front link 23 or the longitudinally extending portion can have a thinner cross-sectional area defining a flex region, allowing the front link 23 to pivot relative to the longitudinally extending portion 57 of the seat, for example, during recline. The tensile base plate 1220 can be positioned along the bottom of the longitudinally extending portion 400 extending forwardly from the first position 406 and along the bottom of the front link 23, the bottom portions of these structures being tensioned during bending and the upper portions of these structures being compressed when the body support assembly is reclined. It will be appreciated that the front link 23 itself can also elastically bend and deform during recline of the body support assembly, but the majority of the elastic deformation is intentionally occurring at the flex region. In one embodiment, the flex region 29 is formed by making the blade 412 thinner than the surrounding region, and also making the blade flat or planar across the width of the blade at the flex region. For example, in one embodiment, the flex region 29 has a length of about 25 mm and a depth of about 2.8 mm, with the adjacent region of the blade having a thickness of 2 to 3 times the thickness of the blade in the flex region 29. In other words, the flex region 29 is introduced by making the blade thin and flat. Thus, the flex region has a smaller moment of inertia than the adjacent region, and is less resistant to bending. As FIG. 95C As shown, the portion 400 is relatively thick between the position 406 and the flex region 29, but can have a greater thickness along its longitudinal centerline, with the portion 400 having a generally elliptical cross-section.

[0158] The rear link 25 is relatively rigid or stiff, meaning that the rear link does not elastically bend or deform during recline of the body support assembly. Rather, the longitudinally extending portion 400 has a thinner region defining a flex region 31 immediately adjacent to and forward of the rear link 25 and the position 410, but rearward of the first position 406. As FIG. 94 and FIG. 95AAs shown, similar to the flexural region 28, the flexural region 31 is defined by a thin and flat cross-section, having a length of approximately 25 mm in one embodiment, and the surrounding region (e.g., the adjacent rear portion 401 of the base link 33 portion 400) has a thickness 2-5 times greater than that of the flexural region 31. The rear portion 401 of the longitudinal extension 400 positioned between the first position 406 and the rear link 25 may have a tension plate 1222 positioned in its upper portion, because this portion or upper surface will experience a tension load when a bending force is applied during tilting, and the lower portion or lower surface will experience a compressive load.

[0159] like FIG. 43 , FIG. 77 and FIG. 78 As shown, the rear portion 401 of the lower support structure 400 extends rearward from the first position 406 and includes an upwardly extending, centrally located arm or strut 407 that partially defines the rear link 25, and flanges 409 on each side of the strut defining a rear edge 416. As explained in more detail below, the back frame 210 and back support 212 also feature partial definition of the rear link 25, and a connector 479 connecting various features. Therefore, the back frame 210 and back support 212 pivot about a common axis defined by the rear flexural region 31. FIG. 103 As shown, flange 409 is received in a groove 411 defined by the lower portion 214 of the back frame, wherein the groove has an opening having a rearwardly tapering, wider mouth, such that flange 409 can pivot slightly relative to the lower portion and roll along the lower surface of the support defining the mouth of groove 411 in order to reduce stress rise at its engagement.

[0160] In operation, the user can move the backrest assembly 6 and seat assembly 8 from a vertical position or tilt them to a tilted position by flexing the four-bar linkage (including portions of the seat assembly). It is conceivable that the four-bar linkage arrangements used and described herein include linkage arrangements with additional link members, such as five-bar configurations, six-bar configurations, etc. In various embodiments, the thickness of one or more links 23, 25, 33, 57, and especially the front link 23, base link 33, and seat link 57 and their predetermined flexural regions, can be positioned to achieve desired performance characteristics, including, for example, link flexibility. Further, in some embodiments, the thickness of the link can vary along the length and / or width of the link to achieve desired flexibility or stiffness across the link or in portions of the link (e.g., at flexural regions 27, 28, 31, and 53). Furthermore, for example, the front link and seat assembly link can be more flexible than the rear link 25 to achieve the desired flexibility of the four-bar linkage. In some embodiments, multiple links may be more flexible in specific portions or local regions of the link, such that the links are substantially flexible in that local region and substantially inflexible or less flexible in any other region of the link. It should be noted that, depending on the desired support and bending characteristics, the relative area of ​​reduced thickness may extend along a short distance or most of the length of the associated link.

[0161] The spacing W1 between the outermost portions of the front link 23 supports provides relative stability to the front portion of the seat, whereby the link 23 resists rotational or torsional movement about the longitudinal axis 2. In contrast, the centrally located rear link 25, with a total width W3, is the sole support for the rear of the seat assembly, allowing for a greater amount of rotational or torsional movement of the rear of the seat relative to the front of the seat about the longitudinal axis 2, while rotational or torsional movement of the front of the seat is limited by the front link 23. In one embodiment, W1 is approximately 290-300 mm, while W3 is approximately 140 mm, where the ratio between W1 and W3 is approximately 2:1.

[0162] Tilt limiter and energy booster:

[0163] Reference FIG. 71 to FIG. 73C , FIG. 77 to FIG. 82D , FIG. 104 as well as FIG. 106A to FIG. 106DThe control module 420 limits the amount of tilt that the seat assembly 8 and backrest assembly 6 can exhibit, while also providing supplemental energy to allow the seat to return to and resume an upright position. Because the front link 23 and rear link 25 are oriented forward / angled, the seat 6 is lifted when the user tilts, providing automatic resistance to tilting (or a weight-actuated mechanism). Specifically, flexure zone 27 is positioned in front of flexure zone 29 at its nominal rest position, and flexure zone 53 is positioned in front of flexure zone 31 at its nominal rest position. Therefore, the chair can resist tilting without any auxiliary springs and will return from a tilted position to an upright position when the user leaves the chair. Similarly, due to the compliant nature of the tilt control mechanism 318, the seat supports, and the backrest, these components can bend or elastically deform in response to load, thereby absorbing energy through elastic deformation. However, for some users, the supplemental energy system helps to improve resistance to tilting. In one embodiment, the system can be adjusted to provide no-slope stop, medium-raise / medium stop, full-raise / full-tilt stop, and no-raise / full-slope stop.

[0164] In one embodiment, the control module 420 includes a housing 422 having a base 426, which is made of casting. A ball retainer housing 428 is made of two parts joined together to define a spherical inner recess 424. A cover 421 or base portion 302 of the armrest assembly is secured to the top of the base 426 with fasteners 505 to further define the housing 422. The retainer housing 428 is inserted into the base 426 below a shield 516 formed in the housing, wherein the retainer housing 428 is secured with a shaft 462. The housing 422 or its hub 405 defines an opening 503 in its bottom wall that receives the top of a support post 16, wherein the housing 422 is securely fixed to the platform 402, for example, with fasteners 505. In one embodiment, a spherical tilt limiter 430, configured as a spherical bearing, is rotatably supported in the recess 424 of the ball retainer housing. The tilt limiter 430 is rotatable relative to the housing 428 about a longitudinal axis 432. A tilt stop member 434, configured with a rod 436 or a portion of a T-shaft, is axially arranged through the spring bushing 438 and the spring 446. A transverse member 440 of the T-shaft moves in a longitudinal groove 442 formed in the sidewall of the spring bushing. The end of the transverse member 440 extends radially outward from the side of the spring bushing, such that the end is exposed for engagement with a plurality of stop surfaces of the tilt limiter. The spring bushing 438 has a first end 448 coupled, for example, to the tension spring 446 by a threaded engagement. The spring bushing 438 includes a pair of protrusions 444 extending radially outward from their opposite sides. In this way, the ends of the transverse member 440 and the protrusions 444 on the spring bushing define different stop members that engage with different stop surfaces 450, 452, 454 formed inside the front end / front surface of the ball bearing or tilt limiter, or along the front end / front surface of the ball bearing or tilt limiter. Surfaces 450, 452, and 454 are spaced apart in the longitudinal direction, with surface 450 being the foremost surface and stop surface 454 being the last surface. Surface 452 may be defined as the front end surface of the ball tilt limiter, or may be longitudinally spaced in front of that surface to provide contact with the protrusions 444 of the spring bushing 438 during all operations of the limiter. The tilt limiter 430 includes a through opening 453 through which the spring bushing 438 and the stop member rod 436 extend, and through the longitudinal center of the spring bushing 438 and the spring 446, which are arranged around the rod 436. exist FIG. 104 and FIG. 105In the illustrated embodiment, the tilt limiter 430 is supported at both ends by spring bushings 438, which include radially extending protrusions 444 or feet that support the tilt limiter 430 during rotation. In this embodiment, the protrusions 444 extend further in the longitudinal direction and also have a greater circumferential length, i.e., extend a greater circumferential distance around the spring bushings 438. The outer surface of the protrusions 444 or feet engages and supports the inner bore of the tilt limiter 430 in all positions, making the tilt limiter more stable. The opposite ends 456 of the rod are securely connected to the T-shaped bushing 458 by internal threads on the bushing 458 and external threads on the ends of the rod. The lateral members 471 of the bushing 458 engage the rear link 25 of the four-bar linkage and are specifically received in a pair of hubs 477 formed on the connector 479 or in a housing defining an axle receiving cavity. Spring 446 has opposing ends 459, 461 that screw onto the external threads of T-shaped bushing 458 and spring bushing 438, respectively, wherein spring 446 is configured as an extendable tension spring extending in the longitudinal direction 432. It should be understood that the rod and spring can be secured to the bushing with other fasteners, including adhesives, friction fits, locating screws, snap-fit ​​fits, pawls, etc. A tubular cover 950 surrounds the rod 436 and spring bushing 438 and provides an aesthetically pleasing cover while avoiding pinch points. Cover 950 is pivotally connected to housing 516, wherein a pair of axles are received in a convex portion, allowing cover 950 to rotate about an axis 956 defined by axle 952, which allows the cover to move and rotate with the rod and spring bushing during tilting.

[0165] In operation, the tilt limiter 430 rotates about a longitudinal axis 432 defined by the spring bushing 438, the spring 446, and the T-bar 436 in 30-degree increments to present different stop surfaces 450, 452, 454 to the ends of the transverse member 440 and / or the protrusion 444 of the spring bushing. In one embodiment, the actuator component 460 includes a hub 472 having a through opening engaged by a shaft 462 having a lead screw 464 with threads 481. FIG. 82A to FIG. 82D and FIG. 106A to FIG. 106DAs shown, the lateral member 440 and the convex portion 444 do not rotate about the axis, but remain stationary as the tilt limiter 430 rotates. When the lead screw 464 is rotated via the handle or knob 466, the rack (slider) 460 moves laterally and axially along the lead screw 464 via interface / engaging teeth 468, 470 defined by the external thread 481 of the lead screw and the internal thread 483 of the hub 472. The thread can be four-pronged or eight-pronged. The actuator further includes a linear rack 474 that protrudes from the hub 472 and is secured to the hub 472 by an arm 473. The rack 474 moves laterally by rotation of the lead screw 464, which can rotate clockwise or counterclockwise to move the rack left and right in the lateral direction 4. The rack includes a row of teeth 475 that mesh with teeth defined by a circumferential rack 476 arranged around the outer surface of the spherical tilt limiter 430. The meshing racks 474 and 476 rotate the spherical bushing 430 within a socket about a longitudinal axis 432 to different angular positions within the spherical retainer housing 428. A pawl 478 is coupled to the end of the lead screw, having multiple surfaces or recesses engaged by a resilient engagement member 480. In one embodiment, the resilient engagement member 480 is formed as a cantilevered end and biased by a spring 491, which releasably engages one or more of the surfaces to ensure rotation of the lead screw by a specific angular amount corresponding to a 30-degree rotation of the spherical bushing. The end 463 of the shaft 462 is rotatably supported by the bushing 482 coupled to the housing 428.

[0166] like FIG. 82C and FIG. 106C As shown, in the fully tilted / fully raised position, the convex portion 444 of the spring bushing engages the front stop surface 450 defined by the front face of the spherical bushing to prevent the spring bushing 438 from moving axially / rearward during tilting. However, the lateral member 440 of the rod moves freely within the groove 442 of the spring bushing. Therefore, during tilting, the rear link 25 engages the T-shaped bushing 458, which pulls the rod 436 rearward as the lateral member 440 moves within the groove 442 of the spring bushing. Since the spring bushing 438 is fixed, the spring 446 (fixed to both the spring bushing and the T-shaped bushing) is stretched or tensioned, thereby applying a restoring force to the rear link 25. When the lateral member encounters the stop surface 454, tilting is prevented (fully stopped).

[0167] exist FIG. 82A and FIG. 106A In the non-tilting stop position shown, the end of the transverse member 440 of the rod 436 engages the front stop surface 450 defined by the ball bushing to prevent the rod, the attached T-shaped bushing, and the rear link 25 from moving rearward.

[0168] existFIG. 82D and FIG. 106D In the fully tilted / unlifted position shown, the spring bushing 438 and the rod 436 move freely in the ball bushing until the rod 436 engages with its rear stop surface 454 in the fully tilted position, but the spring 446 does not extend.

[0169] exist FIG. 82B and FIG. 106B In the shown mid-tilt / mid-lift position, the convex portion 444 of the spring bushing 438 engages the front stop surface 450 of the spherical bushing to prevent the spring bushing from moving axially / rearward during tilting. However, the lateral member 440 of the rod moves freely within the groove 442 of the spring bushing to the mid-stop position, where its end engages the mid-stop surface 452 in the spherical bushing, which is longitudinally rearwardly spaced from the front stop surface 450 but in front of the rear stop surface 454. Thus, during tilting, the rear link 25 engages the T-shaped bushing 458, which pulls the rod 436 rearward as the lateral member 440 moves within the groove 442 of the spring bushing. Since the spring bushing is fixed, the spring (fixed to both the spring bushing and the T-shaped bushing) is stretched or tensioned, thereby applying a restoring force to the rear link 24.

[0170] Importantly, the connection between the recess 424 of the spherical retainer housing 428 and the outer spherical surface of the tilt limiter 430 allows the position of the tilt limiter 430 to be adjusted to different stop / raised positions, but also allows some clearance / rotation to accommodate rotation of the levers and other components during tilting. For example, the meshing racks 474, 476 and the tooth orientation defined therethereby allow the tilt limiter 430 to rotate about a transverse horizontal axis. In one embodiment, the tilt limiter or spherical bushing has at least two rotational degrees of freedom, including, for example, rotation of the tilt limiter about a longitudinal axis 432 and also about a transverse axis, to allow the tilt limiter to float relative to the base and thereby accommodate flexure of the four-bar linkage about the transverse axis and any inherent flexure of the seat and backrest about the longitudinal axis without being confined in the housing 428. The tilt limiter may also have rotational degrees of freedom that allow rotation about an axis orthogonal to the longitudinal and lateral axes (e.g., an upwardly extending axis), so that the lever 436 can rotate left and right to accommodate the movement (i.e., bending and twisting) of the four-bar linkage during use.

[0171] As described above, the tilt limiter assembly is connected between the body support member (e.g., seat and / or backrest) and the base to limit the tilt of the body support member relative to the base. For example, the tilt limiter assembly may be connected between the rear link 25 and the base 12, wherein the rear link is coupled to both the seat and the backrest and controls the tilt of the two components via the rear link 25. In other embodiments, the tilt limiter may be directly coupled to, or directly connected to, the seat assembly 8 or the backrest assembly 6.

[0172] Height adjustment control:

[0173] The control module may also include an actuator 484 coupled to the housing 422 for actuating an actuator button 501 extending from the top of the support column 16. The actuator button can be pressed down by the actuator 484, thereby allowing the support column 16 to extend or be compressed under load. (Refer to...) FIG. 73A to FIG. 73C as well as FIG. 87A and FIG. 87B The actuator 484 includes a handle 486 rotatably mounted about a transverse axis 488 and having a hollow shaft 490 through which a rod 462 and a lead screw 468 extend. An end 492 of the shaft 490 engages and rotates drive gears 494, 1494, wherein a bushing 833 is supported in a housing 422. In one embodiment, the drive gear 1494 is configured with a radially extending arm 1495 having a plurality of teeth 1496 (shown as four teeth) defining a rack 1497. In one embodiment, the rack is a linear rack, wherein the teeth are arranged tangent to a curve having a radius defined by the length of the arm. In other embodiments, the rack may be a partially circumferential rack. In another embodiment, the drive gear can be configured as a segmented gear having a pair of radial sides and an outer circumferential arc, the outer circumferential arc having a plurality of teeth positioned around its perimeter. The drive gear 494 also has a plurality of teeth 496 positioned around a portion of its circumference, and an adjacent circumferential portion 498 without teeth; or in other words, the drive gear 494 has an outer surface 499 arranged radially inward relative to the plurality of teeth 496 to define a circumferential concave portion. The drive gears 494, 1494 are rotatable about a transverse axis 488 from an engaged position to an engaged position.

[0174] An actuator having driven gears 500, 1500 is positioned adjacent to the drive gear and is rotatable about a transverse axis 502 spaced apart from the transverse axis 488. A bushing or cover 847 surrounds an axle 841 extending from the driven gear 1500, the axle 841 being supported by a pair of lugs 853 formed on a housing 422. The engaging member rotates about the axle 841 and / or cover 847 between these lugs. In one embodiment, the driven gear 1500 is configured as a gear segment having a pair of radial sides 1502 and an outer circumferential arc 1504 having a plurality of teeth 1506 positioned around its perimeter. The actuator includes a convex portion or lever 504 extending radially from the axle, the convex portion or lever 504 covering an actuation button on the support post. A compression spring 506 biases the drive gear 494 such that a toothless portion 498 or surface 499 generally covers the driven gear. Driven gear 500 includes a plurality of teeth 508 arranged around at least a portion of its circumference, wherein a concave portion 498 or a surface 499 covers the plurality of teeth 508 when the drive gear is in a non-engaged position. Drive gear 494 is rotatable to an engaged position such that the plurality of teeth 496 engage with the plurality of teeth 508 after the handle 486 has rotated a first predetermined amount about a transverse axis 488. Thus, when the drive gear is in the engaged position, driven gear 500 rotates about a transverse axis 502 from a non-actuated position to an actuated position. The user rotates the handle 486 against the biasing force of the compression spring 506 until the teeth 496 of the drive gear rotate to engage with the teeth 508 of the driven gear, thereby rotating an actuator lever 504 extending from the shaft of the driven gear and actuating a button 517 on top of the support post 16. An integrated spring 510 is formed in the carrier support to provide a slight preload to the button. The driven gear 500 is rotatably supported by a carrier 512, which is coupled to the top of the housing above the top of the support column, wherein the drive gear and the driven gear are connected in a recess 514 formed in the housing.

[0175] Reference FIG. 80 , FIG. 81 as well as FIG. 87A and FIG. 87BIn one embodiment, the spring 960 has a first end 962 that biases the drive gear 1494 to a disengaged position, such that teeth 1496 are arranged below teeth 1506 of the driven gear and do not engage or mesh with teeth 1506 of the driven gear. The spring 960 has opposing ends 964 that bias the driven gear 1500 and lever 504 toward the button 517. In this way, the driven gear 1500 can rotate sufficiently to engage the lever 504 with the button, regardless of the rotation of the drive gear, for example, to accommodate different support posts with different lengths or sizes of buttons, or where accumulated errors have resulted in different button positions. In other words, the initial position of the driven gear can change depending on the type and configuration of the support post and button before engagement by the driven gear, after which the drive gear engages and rotates the driven gear.

[0176] The drive gear 1494 is rotatable to an engaged position, such that multiple teeth 1496 engage and mesh with multiple teeth 1506 after the handle 486 has rotated a first predetermined amount about the transverse axis 488. Thus, the driven gear 1500 rotates about the transverse axis 502 from a non-actuated position to an actuated position when the drive gear is in the engaged position. The user rotates the handle 486 against the biasing force of the spring 960 until the teeth 1496 of the drive gear rotate to engage with the teeth 1506 of the driven gear, thereby rotating the actuator lever 504 extending from the shaft of the driven gear and actuating the button 517 on the top of the support post 16.

[0177] Seat components:

[0178] Reference FIG. 1 to FIG. 7C , FIG. 8 to FIG. 20 as well as FIG. 84A to FIG. 84D The seat assembly 8 is operatively coupled to the tilt control assembly 18 and supports the seating surface 28. The seat has opposite sides spaced apart in a lateral direction and a front and rear portion spaced apart in a first longitudinal direction. The seat assembly includes a lower support platform 30 having a peripheral edge 32, an upper surface 34, and a lower surface 36. In one embodiment, the lower support platform is shown in a plan view (see plan view 28). FIG. 13 The tangent has a roughly isosceles trapezoidal shape, with a front edge 38, a rear edge 40, and a side edge 42 connecting the front and rear edges. The rear edge is shorter than the front edge. The peripheral edge 32 may be stepped, meaning that its peripheral edge portion 66 is thinner than its central portion 68.

[0179] The support platform 30 has a pair of laterally spaced pads 44 positioned at the front portion of the support platform. For example... FIG. 84A to FIG. 84DAs shown, platform 30 includes a protrusion 970 defining a concave portion 974 and an opening 972. Each pad is defined as a hinge portion 976 having a front edge 978 that is secured to a front edge 980 of the platform, the front edge 980 defining the opening 972 in the platform. The hinge portion can be formed by overmolding a more flexible material onto the supporting platform. The hinge portion 976 extends rearward in the opening, with a rear edge 982 spaced apart from a rear edge 984 of the platform defining the opening 972. Each of the pads 44 includes at least one mounting member shown as an opening 46, the opening 46 being shaped and sized to receive a mounting member (e.g., a fastener or stud 988) for securing the platform to a tilt control assembly. This mounting member may include a flange 990 extending forward from link 23 to support the platform. The flange 990 is received in the recess 972 and includes a boss extending upward into the opening 46, such that the flange 990 can be secured to the bottom surface of the padding, particularly the hinge portion 976, using a plurality of fasteners 988. In this embodiment, the flexible hinge portion 976 defines a flexure region 27. This mounting component and connection to the link 23 allow the support platform and the front link 23 to pivot relative to the base link 33 about the flexure region 29, and allow the seat assembly 8 to pivot relative to the front link 23 about the flexure region 27, in both cases by, for example, elastic deformation or bending of the portion of the front link at the flexure regions 27, 29, or alternatively by bending or flexing of the padding or the hinge portion 976. Meanwhile, the spacing W1 between the padding and the front link provides relative stability to the front portion of the seat, resisting rotational or torsional movement about the longitudinal axis. The boss structure 49 extends downward from the rear portion of the support platform. The boss structure 49 defines at least one mounting member connected to the roll control assembly 18, and / or defines a portion of the rear link 25 that partially forms part of the roll control assembly, and allows the support platform and the rear link 25 to pivot relative to the base link 33 about a flexure region 31, which can be performed, for example, by elastic deformation or bending of a portion of the base link 33 at the flexure region 31. In one embodiment, the boss structure 49 has a tubular configuration defining a cavity surrounding or receiving an insertion portion of the rear link 25 configured with features from connectors 479, 219. The centrally located rear link (the sole support for the rear of the seat) allows rotational or torsional movement of the rear of the seat relative to the front of the seat about a longitudinal axis, wherein, as explained above, rotational or torsional movement of the front is limited. The support platform 30 has a generally recessed upper surface 34, wherein a front portion 35 and a rear portion 37 extend upward from the boss structure.

[0180] The support platform can be made of a flexible, elastic polymer material, such as any thermoplastic material, including, for example, nylon, glass-filled nylon, polypropylene, acetyl, or polycarbonate; any heat-set material, including, for example, epoxy resin; or any resin-based composite material, including, for example, carbon fiber or glass fiber, thereby allowing the support platform to conform and move in response to forces applied by the user. Other suitable materials may also be used, such as metals, including, for example, steel or titanium; plywood; or composite materials, including plastics, resin-based composites, metals, and / or plywood. The support platform may have strategically positioned tension substrates 1220, 1222 (e.g., made of glass-reinforced strips) to accommodate bending and deformation of the structure, wherein the strips are under tension during such bending and deformation. Strategic positions on the lower support platform are also provided with specific geometries that allow predetermined deformation and define “flexural regions” (also referred to as “flexural joints”) or virtual pivot positions.

[0181] For example, the support platform may include a reduced thickness region defining a laterally extending flexural region or flexural area 53 located in front of the boss structure 49. This flexural region or flexural area 53 divides or bifurcates the support platform into front and rear portions that may have different lengths or dimensions, wherein the rear portion may deflect downward relative to the front portion during tilting when the flexural region bends. The portion of the support platform extending between the flexural region 53 and the flexural region 27 defines a link in a four-bar linkage, while a portion of the support platform rear of the flexural region 53 partially defines a portion of the rear link 25. It should be noted that, depending on the desired support and bending characteristics, the reduced thickness relative region may extend along a short distance or most of the width of the support platform. The phrase "flexure region" refers to a portion of the structure that allows flexing or bending within a designated area, thereby allowing or providing relative movement (e.g., pivoting) of the component or structure on opposite sides of the flexure region, thereby defining a virtual pivoting position (e.g., a horizontal pivot axis). It should be understood that this virtual pivot axis can move during the flexure and is not defined as a rigidly fixed axis. Various configurations and materials of the support platform may correspond to the configurations and materials of various components shown and disclosed as in U.S. Patent Publication No. 2016 / 0296026 A1 entitled "Seating Arrangement" and U.S. Patent Publication No. 2018 / 0352961 entitled "Seating Arrangement and Method of Construction," the entire disclosure of which is incorporated herein by reference.

[0182] The support ring 48 has an inner ring 50 with an inner peripheral edge 52 defining a central opening 54. The inner peripheral edge 52 surrounds and couples to the outer peripheral edge 32 of the support platform, namely the rear edge 40, front edge 38, and side edge 42 of the support platform 30, which is received within the opening 54. The inner ring 50 has a trapezoidal shape defined by a front member 56, a rear member 58, and a pair of side members 60 defining the opening 54. The inner peripheral edge 52 can be stepped, meaning its peripheral edge portion 70 is thinner than its central portion 72, wherein the edge portion 70 overlaps and engages with the edge portion 66 of the lower support platform. FIG. 7A As shown, edge portion 70 is positioned above edge portion 66, wherein the upper surface of the perimeter edge 52 is flush with the upper surface of the support platform 30. Edge portions 70 and 66 can be secured with fasteners (such as screws and / or adhesives). It should be understood that the support platform 30 and the support ring 48 together define the support frame 62.

[0183] In one embodiment, the support ring 48 further includes an outer ring 74 having side members 76, the outer ring 74 being connected to the side members 60 of the inner ring via a pair of front connectors 78 and a pair of middle connectors 80. A pair of rear three-sided openings 81 are defined between the inner edge of the outer ring 74, the edge of the side member, and the edge of the connector 80. Each opening 81 has an inner side 85, an elongated outwardly curved side 87, and a third side 91, wherein sides 87 and 85 converge along the rear of the opening 81 to define a nose 89, and the third side 91 extends along and defines the connector 80 and connects sides 85 and 87. A pair of front three-sided openings 83 are defined between the inner edge of the outer ring 74, the edge of the side member 60, and the edge of the connector 80. Each opening 83 has an inner side 93, a longer outwardly curved side 95, and a third side 97, wherein sides 93 and 95 converge along the front of the opening 83 to define a nose 99, and the third side 97 extends along the connector 80 and defines the connector 80, and connects sides 93 and 95.

[0184] It should be understood that, in one embodiment, the middle connector 80 may be omitted. The outer ring has a front transverse member 82 and a rear member 58 shared with the inner ring, and the front transverse member 82 and the rear member 58 are connected to the side member 76. The front transverse member 82 is spaced apart from the front member 56, which defines an elongated and laterally extending U-shaped opening 84 between them. A flexible membrane 55 covers the opening 84, is connected to the support ring around the outer edge of the opening, and maintains the spacing between the transverse member 82 and the front member 56 when the transverse member 82 flexes relative to the front member 56 (e.g., when subjected to a load applied by a user's thigh). The membrane 55 may also act as a limiter by limiting the amount of deflection of the transverse member 82 when a load is applied to it. The membrane 55 may be made of polyurethane and may be overmolded onto the support ring 48 to cover the opening 84. The side recess 86 allows the front portion 88 of the side member 76 to flex or bend, enabling the front member 82 to deflect when loaded by the user's leg, while the connectors 78, 80 provide greater stiffness to the outer ring 74. The outer peripheral edge 90 is stepped, meaning its outer peripheral edge portion 92 is thinner than its central portion 72. A pair of lugs 94 extend downward from the inner ring and are arranged along the side of the boss structure, where they are supported by the tilt control assembly 18. The support ring 48 extends radially outward from the lower support platform 30. The support ring, comprising the outer ring, inner ring, and connectors, defines the upper surface 96 and the cavity 98. As described in more detail below, the support ring 48 is made of a compliant flexible material and is configured to position and retain the flexible edge member 162. The support ring 48 is less rigid than the support platform and has a lower elastic modulus than the support platform. The support ring may be made of, for example, polyester-type polyurethane or thermoplastic polyester elastomer.

[0185] The upper housing (also referred to as the load-bearing frame 100) has a central portion 102 covering the inner ring 52 of the support ring and the lower support platform 30, and an outer ring 104 covering the outer ring 74 of the support ring and the upper surface 34 of the support platform. The outer ring 104 and the central portion 102 of the upper housing are coupled to at least two connectors, including a pair of front connectors 106 and a pair of middle connectors 108, which are bent with an upward concave curvature, such that the outer ring 104 and the central portion 102 are rigid and resistant to outward / downward offset / deformation.

[0186] A pair of rear three-sided openings 109 are defined between the inner edge of the outer ring 104, the edge of the central portion 102, and the edge of the connector 108. Each opening 109 has an inner side 111, a longer outwardly curved side 113, and a third side 117, wherein sides 111 and 113 converge along the rear portion of the opening 109 to define a nose 115, and the third side 117 extends along the connector 108 and defines and connects sides 111 and 113. A pair of front three-sided openings 119 are defined between the inner edge of the outer ring 104, the edge of the central portion 102, and the edge of the connector 108. Each opening 119 has an inner side 121, a longer outwardly curved side 123, and a third side 127, wherein sides 121 and 123 converge along the front portion of the opening 119 to define a nose 125, and the third side 127 extends along the connector 108 and defines and connects sides 121 and 123.

[0187] The outer ring 104 has a front transverse member 110 and a rear member 112 connected to the side member 114. The outer ring has a circumferential length defined around its outer edge, which is fixed or maintained relatively constant during seat tilting. In other words, as described in more detail below, in one embodiment, the outer ring 104 defined by the side member 114, the front transverse member 110, and the rear member 112 does not elongate during tilting, or undergoes elastic deformation along its tangent or length in response to tension, although the outer ring 104 is capable of bending or flexing. The front transverse member 110 is spaced apart from the front edge 116 of the central portion 102, and the front transverse member 110 and the front edge 116 define an elongated and laterally extending U-shaped opening 118 therebetween. The side recess 120 allows the front portion 122 of the side member 114 to flex or bend, such that the front transverse member 110 can deflect when loaded by the user's legs, while the connectors 106, 108 provide greater stiffness to the outer ring 104. Connectors 106 and 108 cover connectors 78 and 80, with openings 84 and 118 aligned with membrane 53. The upper housing includes a gasket 124 covering gasket 46. The upper housing 100 is secured to the support platform with fasteners, including, for example, hooks and screws.

[0188] The upper housing or load-bearing frame 100 is flexible but stiffer than the support ring 48 and has a greater elastic modulus than the support ring. However, the load-bearing frame is less stiff than the support platform 30 and has a less elastic modulus than the support platform 30. The upper housing or load-bearing frame 100 can be made of a flexible, elastic polymer material, such as any thermoplastic, including, for example, nylon, glass-filled nylon, polypropylene, acetyl, or polycarbonate; any heat-set material, including, for example, epoxy resin; or any resin-based composite material, including, for example, carbon fiber or glass fiber, thereby allowing the support platform to conform and move in response to forces applied by the user. Other suitable materials may also be used, such as metals, including, for example, steel or titanium; plywood; or composite materials, including plastics, resin-based composites, metals, and / or plywood.

[0189] The middle connector 108 of the upper housing 100 may include a reduced thickness region defining a flexure region or flexure area 155. The upper housing 100 may also have a reduced thickness region defining a flexure region or flexure area 153 on the flexure area 53 of the lower support platform located in front of the boss structure 48.

[0190] The upper housing or support frame 100 has a body-facing upper surface 126, a lower surface 128 opposite to the upper surface 126, and a peripheral edge surface 130 or side edge surface extending between the first surface 126 and the second surface 128. In one embodiment, the peripheral edge surface 130 is substantially planar and has a vertical orientation; however, it should be understood that the edge surface may be curved, curved, or non-planar, and / or may be oriented at an angle different from that of a vertical plane. The support frame 100 defines a cavity 132, wherein an outer ring defines a central opening 134.

[0191] A perimeter groove 136 is formed in or opens outward from the perimeter edge surface 130. The groove 136 extends around at least a portion of the support frame, and in one embodiment, the groove 136 extends continuously around the entire perimeter of the support frame 100. FIG. 7A to FIG. 7CAs shown, the peripheral edge portion 92 of the support frame 62 extends outward beyond the surface 130 of the supporting frame. A peripheral groove 136 defines an insertion plane 137 oriented at an angle α relative to the peripheral edge surface 130 and relative to the adjacent gap G. In several embodiments, α is greater than 0 degrees and less than 180 degrees, and preferably between 30 and 120 degrees, and more preferably between 45 and 90 degrees. Alternatively, the insertion plane 137 is preferably oriented relative to the tangent of the landing portion 144 or the textile material 150 supported thereon, such that the insertion plane is parallel to the landing portion and the tangent, or forms an angle β preferably between 135 and 180 degrees. The peripheral groove 136 has a pair of spaced-apart surfaces (e.g., an upper surface 138 and a lower surface 140) and a bottom 142 connecting the surfaces 138 and 140. The upper surface 126 of the upper housing has a substantially horizontal landing portion 144 and an angled portion 146 extending away from the landing portion and defining a cavity. The landing portion 144 may have a width (W) close to zero, wherein the landing portion is simply defined by the upper corner of the edge surface 130. In one embodiment, as FIG. 92 As shown, a lip portion 139 extending along the front of the support frame partially defines the groove 136. The lip portion 139 has a plurality of protrusions 141 independent of recesses 143, which increases the flexibility of the support frame but provides sufficient rigidity to hold the support.

[0192] Textile material 150 is secured to the support frame 100 across the central opening 134, such that textile material 150 covers the cavity 132. The textile material may be a suspension material or may cover a cushioning pad supported by the support frame 64 and / or the support frame 100. The textile material covers the upper surface 126 of the upper housing and engages the landing portion 144. Textile material 150 wraps around and engages with a portion of the outer peripheral edge surface 130, particularly the upper portion 152 of the peripheral edge surface extending between the groove 136 and the upper surface 126 or its landing portion 144. The peripheral edge portion 154 of the textile material 150 is coupled to the peripheral edge of the upper housing, for example, where the edge portion 154 of the textile material is arranged in the groove 136. In one embodiment, a support 156 formed, for example, by a ring (e.g., plastic or polyester), is used. FIG. 20The support (without textile material shown) can be secured to the edge portion of the textile material, for example, by adhesives, sewing / stitching, fasteners and other means, or by forming a ring arranged around the support. In one embodiment, the support has a surface 158 facing and engaging the textile material and an opposing surface 160 that remains uncovered. The support 156 and the edge portion 154 of the textile material (configured as a suspension material) are arranged in a groove 136 to secure the suspension material across the opening for tension. In one embodiment, the support 156 is formed as a continuous ring of a fixed length, wherein the support 156 is relatively inelastic and resists elongation along its length, but the support can be flexible and bendable so that it moves together with the side member 114 and the outer ring 104 during seat tilting. In one embodiment, as FIGS. 7A-7C As shown, the exposed or uncovered surface 160 of the support 156 directly engages the surface 138 of the groove without any textile material or other substrate between them. The angular orientation of the groove 136 and the support 156 relative to the edge surface helps ensure that the support 156 does not detach from the groove. In one embodiment, the support 156 and the textile material 150, as explained below, are inserted into the groove 136 without any auxiliary fastening system such as adhesives or mechanical fasteners, but rather engage solely through friction when the fabric / suspension material is tensioned.

[0193] In another embodiment, and referring to FIG. 44 and FIG. 45 The support frame 62 includes a bottom wall 518 defining a body-facing surface and a peripheral edge wall 520 having an outer surface 522. In one embodiment, a lip 524 or hook portion defined by a protrusion extends laterally inward from the peripheral edge wall 520 and, together with the bottom wall, defines a channel 526. FIG. 45 As shown, along the side portion of the seat, the lip or latching portion has an engagement surface 528 that angles upward and inward from the peripheral edge wall, while the upper surface of the wall is substantially horizontal. FIG. 44 As shown, along the front of the seat, the upper surface of the lip is angled downwards and inwards, while the mating surface 528 is substantially horizontal.

[0194] The support frame 100 has a body portion 530 and an insertion portion 534. The body portion 530 has a bottom surface 532 that covers and engages with the bottom wall. The insertion portion 534 is received in a channel 526 and engages with the engagement surface 528. FIG. 44 As shown, the load-bearing frame has an upper surface 536, which is angled downwards and inwards to match the top surface of the lip or latching part, allowing the suspended material to abut against the angled surface deformation. FIG. 45As shown, the insertion portion 534 is angled downwards and outwards to mate with the engagement surface. The orientation of the insertion portion 534 facilitates installation because it can be more easily inserted into the channel when oriented at an angle, such that the insertion portion is below the lip 524. Subsequently, the tension force applied by the textile material 150 (configured as a suspension material in one embodiment) applies a torque to the support frame, causing it to press upwards against the bottom surface of the support frame and the engagement surface 528. A flexible edge member 162 is coupled to the outer surface 522 of the peripheral edge wall of the support frame, wherein the lip portion 538 covers the top surface of the support frame. The flexible edge member 162 has an inner surface spaced apart from and facing inwards towards the peripheral edge wall of the support frame, wherein the inner surface of the support frame and the peripheral edge wall define a gap between them. A portion of the textile material is arranged in the gap, wherein the textile material covers the body-facing surface of the support frame. The supporting frame has an outward-facing perimeter edge 540 and includes a groove 542 that opens laterally outward therefrom. The perimeter edge of the textile material is fixed to the support member 156, wherein the edge portion of the textile material and the support are arranged in the groove 542.

[0195] Suspension material:

[0196] In one embodiment, the textile material is made of an elastic woven or knitted material and can be configured as a suspension material having heat-shrinkable yarns and heat-shrinkable elastic monofilaments that shrink in response to the application of energy (e.g., heat applied by radiation or convection). A variety of suitable suspension materials are disclosed in U.S. Patent Application No. 7,851,390 entitled "Two-Dimensional Textile Material, Especially Textile Fabric, Having Shrink Properties and Products Manufacture Therefrom," the entire disclosure of which is incorporated herein by reference. One commercially suitable heat-shrinkable suspension material is SHRINX fabric, available from Krall+Roth, Germany.

[0197] Reference FIG. 56In one embodiment, the suspension material is made of fabric preform 500 having a plurality of heat-shrinkable elastic (elastomer) threads 552 and a plurality of non-stretchable threads 554. In one embodiment, the heat-shrinkable elastic (elastomer) threads 552 are configured as monofilaments extending along a first transverse direction 4 or a warp direction, and in various embodiments, the non-stretchable threads 554 are configured as yarns or monofilaments extending along the same transverse / warp direction 4. It should be understood that the heat-shrinkable elastic threads (e.g., monofilaments) and non-stretchable threads (e.g., monofilaments) may also extend in longitudinal directions 2, 2'. In one embodiment, the heat-shrinkable elastic threads 552 and the plurality of non-stretchable threads 554 alternate in a 1:1 or 2:1 ratio, or as... FIG. 56 The left-right arrangement is shown, with various embodiments having a braiding density of 4-10 elastic threads / cm, more preferably 7-9 elastic threads / cm, and in one embodiment having a braiding density of 8 elastic threads / cm. In other embodiments, the thread ratio can be varied, having more or fewer elastic threads than inextensible threads. In one embodiment, the diameter of the elastic thread is approximately 0.40 mm, and it should be understood that the elastic thread can be made thicker or thinner depending on the desired elasticity coefficient. It should be understood that more or fewer elastic threads can be used depending on the cross-sectional area of ​​the thread. For example, the braiding density can be defined by the total cross-sectional area (longitudinal measurement) of the combined elastic threads per centimeter, including, for example, having a combined cross-sectional area (whether a single thread or multiple threads) of 0.502 mm in various embodiments. 2 / cm and 1.256mm 2 Between / cm, more preferably between 0.879mm 2 / cm and 1.130mm 2 Between / cm, in one embodiment the combined cross-sectional area is 1.005mm. 2 / cm elastic thread.

[0198] In one embodiment, multiple yarn strands 556 are interwoven with elastic and inextensible yarns 552, 554 in the weft or longitudinal directions 2, 2'. When exposed to heat or energy, the inextensible yarns 554 and yarn strands 556 do not shrink and are not elastomers. Instead, after heat shrinkage, the yarn strands 556 provide shape control over the overall suspended material in their final configuration. The yarn strands 556 can be made in various colors (e.g., blue) to provide color to the textile material. Thus, the overall color of the fabric can be easily changed simply by introducing different yarns in the weft direction. Conversely, the elastomer yarns are preferably transparent or black.

[0199] Reference FIG. 55 and FIG. 85The annular support 156 is secured to the fabric blank, for example, by stitching or using nails or other fastening systems, wherein the annular support has a first annular edge 558 and a second annular edge 560. FIG. 44 and FIG. 45 As shown, the annular support is rotatable 180 degrees between a first configuration and a second configuration. In the first configuration, a first annular edge 558 is arranged radially inward from a second annular edge 560, and in the second configuration, the first annular edge 558 is arranged radially outward from a second annular edge 560. When the support is in the first and second configurations, the first annular edge 558 on opposite sides of the support defines a first dimension and a second dimension between opposite sides in a first lateral direction 2, 2', wherein, in one embodiment, the first dimension and the second dimension are substantially the same, meaning that when the support rotates, the first annular edge remains stationary, even if rotated 180 degrees. The support 156 includes an open notch 157 in the second annular edge, which closes and allows the support to rotate from the first configuration to the second configuration. The fabric preform 500 is initially configured to have pouches with additional material at the corners to accommodate rotation of the support at those corners. After rotation, the bracket 156 can be installed in the load-bearing frame 100, wherein the load-bearing frame and the fabric are then mounted or coupled to the support frame 62, wherein the flexible edge 162 is connected to the support frame 62 and arranged around the perimeter of the textile material.

[0200] Energy (such as heat) can be applied to the fabric blank from an energy source, causing the heat-shrinkable elastomer yarn 552 to shrink. In other embodiments, the textile material wraps around or covers a cushioning pad supporting the user or an underlying substrate (such as a plastic mesh or metal mesh), wherein the edges of the textile material are secured to a support frame as described herein. In those embodiments, the textile material 150 may, but not necessarily, be tensioned around the cushioning pad or across the opening 134.

[0201] The flexible edge member 162 is configured as a loop surrounding and coupled to the peripheral edge 92 of the support frame. It should be understood that the loop may be continuous, or the flexible edge member may extend only partially around the perimeter of the support frame 100. The flexible edge member 162 extends upward from the support frame 64 and has an inner peripheral surface 164 or face, which faces inward toward and is spaced apart from the peripheral edge surface 130 of the support frame to form a gap G, for example, but not limited to having a width between 0.50 mm and 1.00 mm. The gap G communicates with a groove 136, meaning that the groove and the gap form an opening or passageway for receiving a continuous, but non-linear, groove of textile material 150. In one embodiment, the inner surface 164 is substantially planar and has a vertical orientation and extends in the Z direction; however, it should be understood that the edge surface may be curved, curved, or non-planar, and / or may be oriented at an angle different from the vertical plane. In one embodiment, the inner surface 164 has a substantially the same shape as the peripheral edge surface 130, such that the gap G remains constant and is independent of the linearity of the surface or the gap G. In one embodiment, the gap G is the same as or slightly greater than the thickness of the textile material, and the gap G may have a thickness of about 0.75 to 1.00 mm, while in other embodiments, there is no gap (i.e., G = 0), or the gap G is less than the thickness of the textile material, wherein surfaces 130, 164 abut and / or press or slightly compress the textile material 150 between surfaces 130, 164. The inner surface 164 faces and covers the groove 136 and the textile material 150. Furthermore, the flexible edge member 162 further recesses into the support 156 and the textile material 150, thereby further helping to ensure that the support 156 does not detach from the groove 136.

[0202] The flexible edge member 162 is made of a thermoplastic olefin or thermoplastic elastomer and may be made of the same material as the membrane 53, such that the flexible edge member can be compressed, for example, upon impact. The flexible edge member 162 has greater elasticity or is more flexible than the support frame 62 and has a substantially lower modulus of elasticity than the support frame 62, wherein the hardness is in the Shore hardness D range, with one embodiment having a hardness of 80-90. The flexible edge member 162 protects the textile material 150 from unintentional impacts and abrasions and has an upper surface 166 that is substantially flush with or slightly lower than the upper surface 168 of the textile material 150, thereby preventing obstruction and providing a pleasing appearance. As described above, the flexible edge member 162 is adjacent to, or slightly spaced from, the portion of the textile material 150 arranged between the flexible edge member 162 and the support frame 100. The flexible edge member has a groove 170 in which the peripheral edge 92 of the support ring is arranged. In one embodiment, the flexible edge member 162 is overmolded onto the peripheral edge 92 or support ring of the support frame 62 and may be made of the same material as the membrane 53. In other embodiments, the flexible edge member may be secured to the support frame by friction or with adhesives, mechanical fasteners (such as nails or screws), or a combination thereof. The geometry of the flexible edge member 162 further enhances its protective and resilient properties. For example, the flexible edge member 162 may taper from a first thickness T1 along the inner surface 164 to a second thickness T2 at its outermost peripheral edge, wherein the thickness is measured parallel to the inner surface 164 or substantially in the Z direction. In one embodiment, the nose tapers to a point where T2 = 0. In one embodiment, the cross-section of the flexible edge member 162 has a circular nose shape. FIG. 7B As shown, the flexible edge member 162 can be compressed in response to a load applied in the X and / or Y directions, or can be flexed in response to a load applied in the Z direction.

[0203] In one embodiment, an auxiliary support member 200, shown as a cushioning pad, is arranged between the upper surface 126 of the support frame 100 and the bottom surface 190 of the textile material 150. The auxiliary support member 200 is configured to suspend the material or is defined in the space between the upper surface 126 and the bottom surface 190. The upper surface 202 of the auxiliary support member 200 is spaced apart from the bottom surface 190 of the suspended material such that when the suspended material is in an unloaded configuration (i.e., the user is on the suspended material), a gap G2 or space is defined between the upper surface 202 and the bottom surface 190. In various embodiments, the gap G2 may remain constant, wherein the cushioning pad has a contoured upper surface 202 that matches the profile of the bottom surface 190 of the suspended material. In various embodiments, the gap G2 is greater than 0 mm and less than 5 mm, and in one embodiment is 3 mm, such that the suspended material contacts the auxiliary support member 200 once the user engages or sits on the suspended material. The auxiliary support member 200 may have a generally trapezoidal shape in plan view that matches the shape of the central portion 102 of the support frame or the support platform 30. The auxiliary support member 200 extends forward to cover the opening 118 and support the user's thigh. The auxiliary support member may be made of foam. The auxiliary support member 200 can be secured to the support platform 30 and / or the load-bearing frame 100 with fasteners, including mechanical fasteners such as screws or adhesives. In one embodiment, as... FIG. 20 As shown, the auxiliary support member 200 has a bottom substrate 201 (e.g., plastic or wood chip), which can be engaged with fasteners and connected to or embedded in the upper foam cushioning pad 203.

[0204] During operation, and referring to FIG. 18 , FIG. 19 and FIG. 21 When a user sits on the suspension material 150, the load applied to the suspension material 150 causes it to deflect downward toward the auxiliary support member 200. If the load causes the suspension material to deflect across a distance G2 and come into contact with the auxiliary support member 200, the auxiliary support member 200 can then absorb additional load and support the user.

[0205] It should be understood that, in other embodiments, the auxiliary support member 200 abuts against and supports the textile material in its unloaded state. For example, the textile material may simply cover the cushioning pad, which fills the space of the cavity 132 of the support frame, wherein the textile material forms a decorative cover on top of the cushioning pad.

[0206] In one embodiment, a method of manufacturing or assembling the body support member 10 includes positioning and securing an auxiliary support member 200 to the top of a support frame 100. The method further includes arranging peripheral edge portions 154, 252 of textile materials 150, 234 in peripheral grooves 136, 244 formed in peripheral edge surfaces 130, 246 of the frame, wherein the supports 156, 250 engage one surface of the groove. When the supports 156, 250 are rolled up for insertion into the groove, the suspension material covers the portion of the peripheral edge surfaces 130, 246 between the groove and the upper (or front) surface 126 (i.e., the first surface of the frame facing the body). The support frames 100, 242 are then connected to support frames 62, 236, which have flexible edge members 162, 240, for example, secured thereto by support rings 48. In contrast, the flexible edge member 162 can first be connected to the support frame 100, for example, via the support ring 48, after which those components are coupled to the support platform 30. In one embodiment, the flexible edge member 162, 240 is secured to the support frame 62 or the support ring 48 by overmolding the flexible edge member 162 onto the peripheral edge 92 of the support frame / support ring. The flexible edge member can be secured in other ways, including with adhesives or mechanical fasteners. Energy (e.g., heat or thermal energy applied by radiation or convection) can be applied to the suspension material 150, 234, causing the suspension material to contract and generate tension therein. Energy can be applied to the suspension material before or after the support frames 100, 242 are secured to the support frames 62, 212. When the suspension material contracts, the suspension material is tensioned across the opening 134, and the supports 250, 156 are anchored in the slots 136, 244.

[0207] Backrest assembly:

[0208] Reference FIGS. 1-6 , FIG. 7B , FIGS. 22-43 and FIGS. 77-79The backrest assembly 6 includes a backrest frame 210 and a backrest support 212 (also referred to as a support frame). The backrest frame is relatively rigid, meaning that it does not substantially flex / bend or otherwise elastically deform during tilting. The backrest frame 210 has a lower portion 214 that connects to a rear portion of the tilt control assembly 18. The portion 214 includes an upwardly extending arm 992 or strut structure having a forward-facing cavity 994, in which the arm 407 is arranged or nested. The connector 479 has a downward-facing cavity 938 in which the arms 407, 992 are arranged or inserted, thereby clamping and securing the arms 407, 992 together to at least partially define the rear link 25. The front wall 944 of the connector (partially defining cavity 938) has a forward-curved lip that transitions toward and engages with the lower portion 400, while the rear wall 946 is nested in a recess defined by the rear portion of the arm 992. The lower portion 214, or lower support arm, extends generally horizontally in the longitudinal direction 2' along the central axis of the seating structure. Lugs 94 of the seat assembly extend downward from the inner ring and are arranged along the side of the boss structure 49, wherein the lugs 94 are arranged in the cavity or otherwise secured to the arm and the rear link. FIG. 79 As shown, the boss structure 49 covers the top of the cavity and captures the transverse member 471 therein, wherein the upper portion 940 of the connector 479 defines an insertion portion received in the boss structure 49. FIG. 78 As shown, the boss structure 49 and the connector 479 define a forward-facing opening 942, through which the end of the cover 950 is arranged. The back frame 210 is pivotable together with the rear link 25 about the flexure region 31, wherein the lower portion 214 is an extension of the rear link 25 and partially defines the rear link 25. The back frame 210 is pivotable rearward relative to the base 12 during tilting.

[0209] In one embodiment, the transition portion 216 is curved and defines a rearwardly convex, arched shape extending rearward and upward from the lower portion 214. A pair of laterally spaced upright portions 218 extend upward from the transition portion 216. The back frame 210 further includes an upper transverse member 220 extending between and connecting the upper ends of the upright portions 218, wherein the transverse member 220, the upright portions 218, and the lower portion 214 define a central opening. The lower portion, upright portions, and transverse member, including a portion of the rear link (arm 992), may be integrally formed. FIG. 49As shown, the cross-section of the upright portion 218 is angled forward and outward, which increases the (bending) moment of inertia of the upright portion and thus causes the upright portions to combine to resist deflection or bending about the transverse axis 4, and also to resist deformation in the transverse direction, i.e., to resist bending about the horizontal longitudinal axis 2'. It should be understood that, in alternative embodiments, the back frame may include a single upright portion, such as a central ridge member arranged along the longitudinal centerline of the backrest, wherein laterally extending arms have ends connected to the back support. Alternatively, the upright portion may be configured as a housing extending laterally between side portions and having side portions connected to the back support. The back frame may also be configured with more than two upright portions.

[0210] The back support 212 (also referred to as a support frame) is flexible and includes flexural regions 225, 233, which allows the back support to bend and deflect in response to a user leaning in the body support structure. The back support has opposing sides spaced apart in the lateral direction and a top and bottom spaced apart in the longitudinal direction. The back support or support frame 212 includes a pair of laterally spaced uprights 222, each upright having a forward-facing convex arched portion 223 at a first location near the waist region of the back support, wherein each convex arched portion 223 includes and defines a flexural region 225, which may be configured with a thinner and flatter cross-section or segment having a lower, for example, moment of inertia about a horizontal axis than adjacent or remaining portions of the upright. It should be understood that, in alternative embodiments, the back support may include a single upright, for example, extending laterally between side portions of the back frame and having a housing connected to the side portions of the back frame. The housing may be made of flexible plastic. The housing may have a flexural region laterally defined across its entire width adjacent to the waist region. The housing may have a forward-facing concave profile, with side portions positioned in front of the central portion and defining a lateral space therebetween, and the housing may support suspended material fixed to the side portions across the lateral space, for example, using the brackets disclosed herein. If a single upright is configured, the back support can be connected to the back frame via a pair of connectors arranged along each side of the single upright, regardless of whether one or more uprights are configured.

[0211] The bottom portion 224 extends between and connects to the upright portions. The back support 212 further includes a lower portion or support arm 226 extending forward from the bottom portion, wherein the support arm or lower portion is coupled to the control assembly, and in particular to the rear link 25 below the seat support member 6. The lower portion includes a transition portion 217 connecting the support arm 226 and the bottom portion 224. The transition portion 217 has a rearwardly convex arcuate shape, wherein the curved transition portion 217 also has a forwardly concave bowl-shaped shape, wherein the curvature of the transition portion makes it relatively rigid, or resistant to deflection or bending. The front end of the lower portion 226 has an upwardly flared central lip 219 or support rod and a pair of laterally spaced lugs 221, which partially surround an upwardly extending boss structure 998 on the connector 479. The lip 219 and lugs 221 connect to and define a portion of the rear link 25, wherein the seat platform, seat support, back frame, and back support all have overlapping portions that partially define the rear link. The lip 219 is captured by the rear wall 331 of the boss structure 49. A relatively thin and flat section 231 of the lower portion extending in the longitudinal direction 2' is defined below the seat support and seating surface and in the flexural region 233 of the lumbar region 223 of the rear link 25 and the backrest, and the flexural region 225 defined theretherein, which allows the transition portion 217 to pivot relative to the rear link 25 about the flexural region 233. The thinner and flatter cross-section has a lower bending moment of inertia about the horizontal axis than the adjacent portion or the remainder of the lower portion. In one embodiment, one or both of the flexural regions 225 and 233 may be formed as a movable hinge, or a thin flexible hinge made of the same material as more than two rigid blocks connected to the movable hinge, so as to provide relative rotation or pivoting between the more rigid blocks by bending of the movable hinge.

[0212] The flexural region 225 is defined in each of the upright portions 222 in the waist region adjacent to the seating surface, wherein the waist region of the upright portion has a forward-facing convex curvature. For example... FIG. 25 , FIG. 37 and FIG. 39 As shown, when viewed from the right side, the back support has an S-shaped profile. The upright portion 222 of the back support is coupled to the upright portion 218 of the back frame by a connector 228. The upright portions 222 are arranged laterally outward and forward relative to the upright portions 218, wherein a lateral space is defined between the upright portions 222. The back support 212 is pivotable together with the back frame 210 and the rear link about a flexural region 31. In one embodiment, the upright portions 218, 222 may be pivotally connected to a mechanical pivoting engagement comprising, for example, a pivoting structure disclosed in U.S. Patent Application 9,826,839, the entire disclosure of which is incorporated herein by reference.

[0213] In another embodiment, each of the paired connectors 228 extends laterally between one of the back frame uprights 218 and one of the back support uprights 222. The connector includes a first connector protrusion 570 extending laterally from the back frame upright and a second connector protrusion 572 extending laterally from the back support upright, wherein the first connector protrusion 570 and the second connector protrusion 572 overlap. The connector protrusion 572 is disposed behind the cover of the connector protrusion 570. The connector protrusion 572 is relatively rigid and not flexible, such that the back support 212 cannot move relative to the back frame in the front / back direction at the location of the connector 228. The first connector protrusion 570 has a first insertion portion 574 received in a channel 576 or recess formed in the back support upright, while the second connector protrusion 572 has a second insertion portion 578 received in a channel 580 or recess formed in the back frame upright. The first connecting protrusion 570 and the second connecting protrusion 572 are coupled to a vertically extending pin 582 at a position between the first and second upright portions, close to a neutral pivot axis extending in the lateral direction. The first connecting protrusion 570 has a through opening or a horizontally elongated groove 584 at its midpoint, and a pair of lugs 586 extending forward from the front surface of the protrusion adjacent to the top and bottom of the groove 584, wherein the lugs define axially aligned through openings 590. The second connecting protrusion 572 includes a forward-facing lug 588 extending from its front surface, wherein the lug 588 is inserted through the groove 584 and has a through opening aligned with the opening 590 of the lug. The pin 582 is inserted upward through the opening of the lug on the front side of the connecting protrusion to secure the protrusions 572 and 574 to each other. Pin 582 may have a head and be threaded into one or all of lugs 588 and 586, and preferably at least into the uppermost lug 586. Suspension material 150 is arranged on the front of the convex portion, above the pin and lugs, and covers the front of the convex portion, the pin and lugs.

[0214] When the back support flexes relative to the back frame 210 and the rear link 25 about the flexure regions 225 and 233, the non-cylindrical insertion portions 574 and 578 can rotate relative to the channels or sockets 576 and 580 about the laterally extending axis 592. Each connector protrusion includes a shoulder portion 594 abutting the stop surface 596 of the opposing upright portion to position the connector protrusion and align the lugs.

[0215] Reference FIG. 52 as well as FIGS. 74-76The insertion portion 574 of the first connecting member convex portion 570 has opposing forward-convex curved engagement surfaces 598 and 600, which engage with opposing stop surfaces 599, 601 of a channel or recess 576 having a substantially rectangular cross-section. Thus, the upright portion 222 and the channel 576 can rotate or pivot relative to the insertion portion 574 about the axis 603 in a first and second rotational direction until the engagement surfaces 598, 600 on the opposing ends 602 of the insertion portion abut at their opposing ends against the opposing stop surfaces 599, 601 defined by the walls of the channel or recess, thereby limiting pivoting movement in either rotational direction. FIG. 50 As shown, the rear surface of the connector protrusion 570 also has a rearward-facing curved surface 604, which contacts the flat surface 606 of the overlapping connector protrusion 570 so as not to inhibit the rotation of the upright portion 222 and the connector protrusion 572 relative to the first connector protrusion 570, which is relatively rigid and does not move.

[0216] Reference FIG. 74 The insertion portion 578 of the second connecting protrusion 572 is also configured with a convex curved surface 608, which allows the connecting protrusion 572 to pivot relative to the channel 580 and the upright portion 218. In this way, the back support upright portion 222 pivots or rotates relative to the back frame upright portion 218 about the wheel axis 592 between various pivot positions (including at least a first pivot position and a second pivot position), wherein the insertion portion 574 engages the first stop surface and the second stop surface of the first channel 576, and the insertion portion 578 engages the first stop surface and the second stop surface of the channel 580. For example, but not limited to, the upright portion 222 can rotate 5 degrees and 7 degrees relative to the upright portion 218.

[0217] The spacing W2 (e.g., approximately 330 mm in one embodiment) between the connectors 228 on opposite sides of the back support provides relative stability to the upper portion of the back support 212, resisting rotational or torsional movement or forward / backward bending or deflection about the longitudinal axis 2. In contrast, the centrally located rear link 25 (which is the sole support for the bottom of the back support 212) and its total width (W3) allow rotational or torsional movement of the bottom 224 of the back support relative to the top of the back support about the longitudinal axis 2', wherein rotational or torsional movement of the top of the back support is limited as previously explained. In one embodiment, the ratio of W2 to W3 is approximately 2:1 or greater.

[0218] Although the two support arms pivot about the same flexural region 31 due to their common connection with the vertically extending and rigid rear link 25, the lower portions 214, 226 of the back frame and back support or the support arms are vertically separated and define an open lateral passage through them.

[0219] Furthermore, because the seat support 6 and the back support 212 are independent and independently connected to the rear link 25 and thus can pivot independently relative to the rear link 25, the left-right rotation of the rear portion of the seat and the bottom of the back support is not restricted by their connection to each other. In other words, the rear portion of the seat assembly 8 is not directly connected to the back support 212; instead, the seat assembly 8 and the back support 212 are interconnected only through the centrally located rear link 25, allowing the rear portion of the seat assembly 8 and the bottom of the back support 212 to rotate independently about their respective longitudinal axes 2, 2'. Similarly, the back frame 210 is also supported at its lower portion 214 by the centrally located rear link 25.

[0220] The back support 212 includes an upper member 230 extending between and connected to the upper ends of a pair of second upright portions 222, and a bottom portion 224 extending between and connected to the lower ends of the pair of second upright portions. The upper member 230, the upright portions 222, and the bottom portion 224 define a central opening 232. Suspension material 234 extends across the central opening 232 and is secured to the back support 212 in a manner similar to that of a seat.

[0221] In particular, such as FIG. 7BAs shown, an upper member 230, a bottom portion 224, and a pair of second upright portions 222 define a support frame 236 having a peripheral edge 238. A flexible edge member 240 is fixed to the peripheral edges of the upper member 230 and the upright portions 222, or along a surface of the bottom portion 224. A load-bearing frame 242 is coupled to the support frame 236 and includes a peripheral groove 244 facing outward from a peripheral edge surface or face 246, which is horizontally oriented between the front and rear surfaces of the load-bearing frame, as disclosed above with respect to the seat assembly. The peripheral groove 244 is spaced apart from and defines a space or gap G between the inner surface or inward-facing surface 248 of the flexible edge member 240. The groove 244 opens outward from the load-bearing frame 242 along its peripheral edge 246. The suspension material 234 includes at least one bracket 250 (configured as a ring in one embodiment) secured along the peripheral edge portion 252 of the suspension member, wherein at least one bracket is arranged in a groove 244. The bracket 250 can be held in place solely by friction without any auxiliary support material such as adhesives. In one embodiment, the bracket 250 directly engages one surface (e.g., the front surface) of the groove 244, while the fabric engages the rear surface. Thus, as with the seat, the bracket engages the surface of the groove 244 closest to the fabric-covered surface of the supporting frame. In one embodiment, the bracket 250 is formed as a continuous ring of fixed length, wherein the bracket 250 is relatively inelastic and resistant to elongation along its length, but it can be flexible and bendable.

[0222] In another embodiment, and referring to FIG. 46 , 47 88 and 89, the support frame 236 includes a rear wall 800 defining a body-facing surface 802, an outer peripheral edge wall 804 having an outer surface 806, and an inner peripheral edge wall 808, wherein walls 804 and 808 define a forward-facing channel 810. A lip 812 or latching portion extends laterally inward from the outer peripheral edge wall and, together with the rear wall 800, defines a channel 816, wherein the rear surface of the lip defines an engagement surface 814. FIG. 88 As shown, the lip 812 may be defined or include a plurality of engagement members 815 spaced apart around the perimeter of the support frame 236. FIG. 90In one embodiment shown in Figure 91, the portion of the lip 812 extending along the top of the frame has a plurality of spaced notches 839 or grooves that make the top portion of the support frame more flexible, allowing the support frame to be more easily installed (e.g., buckled) within the support frame. Simultaneously, the lip 812 (or the plurality of protrusions 841 defined by the grooves) remains sufficiently rigid to engage supports attached to the periphery of a fabric suspension material wrapped around the support frame, wherein the supports are secured in slots 816. In one embodiment, the support frame 820 has a body having a rear flange 822 and an insertion portion 824, the rear flange 822 defining a rear surface that covers and engages the rear wall, and the insertion portion 824 being defined by a plurality of protrusions 825 spaced apart around the periphery of the support frame 820.

[0223] The insertion portion 824 is received in the channel 816 and engages with the engagement surface 814. The support frame 820 further includes a pair of upper lugs and a pair of lower lugs 827, which align with lugs 829 on the support frame 236, wherein fasteners 831 secure the lugs 827, 829 to further connect the support frame 236 and the support frame 820. The support frame 820 includes a second flange 826, which, together with flange 822, forms an outwardly facing groove 830 and defines an outer peripheral edge wall 827. The flange 826 extends across the channel 810, wherein the edge 832 is positioned adjacent to the inner peripheral edge wall 808 and closes the channel. Tension applied by the textile material (configured as suspension material 150 in one embodiment) then applies a torque to the support frame 820, causing the support frame to press upward against the bottom surface of the support frame and the engagement surface. A flexible edge member 240 is coupled to the outer surface of the peripheral edge wall 804 of the support frame, wherein a lip portion covers the top surface of the support frame. The flexible edge member 240 has an inner surface spaced from and facing inward toward the peripheral edge wall of the support frame, wherein the inner surface of the support frame and the peripheral edge wall 827 define a gap between them. A portion of textile material is disposed in the gap, wherein the textile material covers the peripheral edge wall 827 and the body-facing surface of the support frame. The peripheral edge of the textile material is secured to a bracket 156, wherein the edge portion of the textile material and the support are disposed in a groove 830. The support frame 242 can be secured to the support frame using overlapping protrusions 815, 825 and fasteners 831 (including mechanical fasteners and / or adhesives).

[0224] Reference FIGS. 29-36 , FIG. 54 A and FIG. 54 B and FIG. 55Another embodiment of the backrest assembly 700 includes: a back support 702 having first and second laterally spaced upright portions 704, each upright portion 704 having an upper portion 706 and a lower portion 708 defining an independent forward-facing first convex curvature / bending surface 710 and a forward-facing second convex curvature / bending surface 712; and a lateral member 714 extending between and coupled to the upright portions at a joint between the upper portion 706 and the lower portion 708. Both the upper and lower portions may include lateral member portions 713, 715, which, when the upper and lower portions are joined, have overlapping flanges to define the entire lateral member 714. The upper and lower portions define a forward-facing concave bending surface 711 at their joint. A suspension material 150 (preferably configured as a single piece of material or a blank) is connected to the first and second upright portions 704 and spans a central opening between the first and second upright portions. The suspension material has a front surface and a rear surface. At least the opposite side portion 716 of the suspension material abuts against and conforms to the contours of the upper portion 706 and the lower portion 708, including forward-facing first and second convex curvatures covering and engaging the front surface of the upright portions, and concave curvatures covering the joint. A lateral extension bracket 718 is coupled to the suspension material and extends between the rear surface of the suspension material and the lateral member 714 to pull the suspension material 150 rearward toward the lateral member 718, thereby defining a joint 717 and providing forward-facing convex and concave curvatures along a central portion of the suspension material, which is laterally spaced relative to the upright portions and located in a central position. As elsewhere herein (e.g. in FIG. 46 and FIG. 47 As disclosed herein, the perimeter of the suspended material is connected to the back support by a bracket. As disclosed elsewhere herein, the lower portion 708 of the upright portion 704 is connected to the upright portion 218 of the back frame by a connector 228.

[0225] The transverse member 718 has a forward-facing and laterally extending groove 720 and a laterally extending cavity 722 disposed behind the groove. The bracket 718 has a head portion 724 disposed in the cavity and a neck portion 726 extending through the groove. The bracket is sewn to the suspension material. The bracket includes a first thinned region 728 formed along its length, along which the bracket is sewn to the suspension material. The bracket is elastically flexible. In a pre-installed configuration, the bracket has a flat surface 732 that rests against the suspension material, allowing the suspension material and the bracket to be easily translated and processed under a sewing machine. The neck member is connected to the head portion adjacent to a second thinned region 730, which defines a flexural region. The head portion includes a hook member 734 extending upward from the flat surface. After the bracket is secured to the fabric, the bracket can then be bent, wherein the head portion 724 can rotate relative to the neck portion from the insertion position to the holding position. In the insertion position, the head can be inserted through the groove 720. In the holding position, the head portion and, in particular, the hook member 734 are held in the cavity, and the hook portion engages one or more edges of the channel 720.

[0226] Reference FIGS. 57-59 The lumbar support 900 includes a central pad 902, one or more elastic strips fixed to and extending laterally outward from the pad, and hooks 906 fixed to the ends of each strip. The hooks 906 wrap around the outer edge of the back support and slide there to various vertical positions as needed by the user. A pair of inner pads 904 are arranged on and slide along the inner surface of the support, helping to maintain engagement of the hooks on the support. Due to the elastic / resilient nature of the strips, the hooks can move inward / outward relative to the pads to accommodate different dimensions between the uprights 222. Furthermore, the elastic strips allow the hooks to rotate, for example, when sliding along curved portions of the uprights and / or the lower portion of the back support.

[0227] In alternative embodiments, such as FIGS. 96-99B As shown, a lumbar support 1100 is connected to a pair of uprights 222 that define a portion of the span opening of the frame. The lumbar support extends between the uprights and has a pair of hooks 1102 that connect to opposite ends of the lumbar region. For example, in... FIG. 99A and FIG. 99BAs shown, due to the elastic connection between the waist and the hook, the hook can pivot or rotate relative to the waist, thereby allowing the hook to conform to the curved profile of the upright portion 222 of the frame, while the waist remains taut across the opening, wherein the waist support 1100 is in a high position and a low position, respectively. The waist support has a central pad 1104 having a pair of grooves 1106 extending along its upper and lower edges. The annular belt 1108 includes an upper cord 1110 and a lower cord 1112 positioned in the groove, wherein an annular end portion 1114 extends between and connects the upper and lower cords. The annular end portion is arranged in a U-shaped groove 1116 formed on the inner end of the adapter 1120 or the hub 1118. The hub has a pair of spaced-apart lips 1122 that partially define the groove and retain the end portion 1114 in the groove. The end portion 1114 is inserted or pressed into a groove, wherein the lip 1122 holds the end portion. The adapter includes an insertion portion 1124 or flange having a flexible protrusion 1126 or pawl extending laterally from the flange. The insertion portion 1124 extends laterally from the hub and inserts into a passage 1128 in the end of the hook. The adapter includes a shoulder 1130 defined at the engagement of the hub and the insertion portion, the shoulder 1130 engaging an inner abutting surface 1132 of the hook defined by an inner wall or flange. The outer surface 1134 of the wall has a pair of angled surfaces defining a apex or pad that engage an inner surface of the frame upright 222 but allows sliding relative to the inner surface of the frame upright while helping to maintain engagement with the upright. The protrusion 1126 snaps into engagement with an opening 1136 formed in the hook communicating with the passage. In this way, the central pad 1104 is coupled to the pair of hooks 1102. For example... FIG. 99B As shown, the annular band including the upper and lower curtains allows the hook 1102 to rotate slightly relative to the padding 1104, for example, as the lumbar support moves along the lower portion of the upright section of the back frame, the upright section of the back frame tapers inward toward the centerline. The annular band 1108 is flexible, wherein the curtains 1110, 1112 are slightly pre-tensioned when the hook engages with the outer edge of the back frame. Due to this pre-tension, the lumbar support 1100 remains engaged with the frame even as its width decreases as the lumbar support moves toward the bottom of the backrest.

[0228] Reference FIG. 96A central padding 1104 (e.g., a printed or foam padding) may be fitted within an elastic sleeve. The end of the sleeve may be coupled to an adapter (e.g., a surface of the adapter) and abuts the end surface of the hook, wherein the hook and sleeve are flush at their engagement. The sock is made of an elastic material such as a knitted material. In this way, the sock provides both a pleasing aesthetic appearance and functionality, allowing the waist to be tensioned and stretched or shortened between the frame members. The elasticity of the sock maintains tension even when the hook is closer to the curved bottom of the frame. The front portion of the padding or the sleeve covering the padding engages with the rear surface of the suspension material and provides lumbar support to the user.

[0229] Reference FIGS. 100-102 The backrest may be configured with an adjustable headrest 1000. This headrest includes an (inverted) J-shaped strap 1002 forming a hook 1004, which is fitted over the top of an upper portion 706 (e.g., its transverse member) or over an upper member 230 via a friction / clamp engagement. The hook may have a forward-extending lip 1010 fitted below and engaging with the underside of the transverse member. The strap has downwardly extending legs 1006 positioned along the front surface of the backrest. These legs include mounting portions 1008, shown as platforms with a pair of fastener openings.

[0230] The headrest includes an insertion frame 1012 having a central rail 1014 with a plurality of teeth 1016 on one side. A ratchet block 1018 is inserted into the rail. The ratchet block is securely coupled to a leg mounting portion 1008 or platform by a pair of fasteners 1020, with the frame 1012 sandwiched between them. The block 1018 includes a flexible pawl 1028 extending laterally from the block. A cushioning pad 1024 (which may be a fabric-covered suspension material or a foam component) is attached to the frame, for example, by engaging a perimeter groove 1022 extending around the perimeter of the frame. The headrest 1000 is vertically movable relative to the fixed ratchet block 1018, which moves within the rail 1014. The flexible ratchet pawl or arm flexes laterally, with its end portion engaging at least one of the teeth 1016 to rotate the headrest onto the leg 1006. The headrest 1000 can be gripped and moved vertically to position it at a desired location along the length of the strap, wherein the pawl 1028 flexes into and disengages from the tooth 1016. FIG. 101 As shown, the headrest 1000 has a low profile and can be located almost entirely within a concave portion defined between the upright portions of the upper portion 706.

[0231] operate:

[0232] During operation, and referring to FIG. 18, FIG. 19 , FIG. 21 and FIG. 55 User 101 can sit in body support structure 10. Depending on the user's weight, the amount of deflection of suspension material 150, and the deflection of the side portion of the support / load-bearing frame coupled to the suspension material, the suspension material may engage the upper surface 202 or cushioning pad 203 of auxiliary support member 200, which then helps absorb the user's load. Essentially, the side portion deflects inwardly to a first load configuration by a first amount in response to a load applied to the elastic material, and substantially defines a first spring to absorb the user's load. The elastic textile material or suspension material 150 coupled across the opening to the side portion 114 deflects downwardly to a second load configuration by a second amount in response to a load applied thereto, and defines a second spring to absorb the user's load. In other words, the deflection of the frame or side portion and the deflection of the suspension material combine to provide a first amount of support to the user. When the first deflection amount and the second deflection amount, or the first support amount, cause the elastic material to contact the cushioning pad, the cushioning pad disposed below the textile material engages the elastic material and provides auxiliary support to the elastic material. The cushioning pad defines a third spring to absorb the user's load. When the side portion 114 is in a first no-load configuration and the elastic suspension material 150 is in a second no-load configuration, the upper surface of the cushioning pad 203 is spaced apart from the textile material. In this way, the flexible support / bearing frame, the elastic suspension material, and the cushioning pad provide a first, second, and third amount of elastic support to a user engaged with and supported by the textile material, wherein the suspension material and the flexible frame work together. It should be understood that the elastic suspension material 150 may deflect downward by a first amount in response to the deflection of at least one side portion 114 or both side portions (depending on the location of the applied load).

[0233] The elasticity and deflection of the side portion 114 are primarily a function of the deflection of at least one connector 80, 108 extending between the central portion 102 and the support platform 30 and the side portion 114. The connectors 80, 108 extend upward and outward from the central portion and are curved into upward-facing concave surfaces, making them rigid and resistant to outward / downward offset / deformation. As described above, the connectors 80, 108 include a pair of opposing side connectors that deflect inward from a first unloaded configuration to a first loaded configuration in response to a load applied to the elastic material.

[0234] User 101 can tilt, wherein the tilt control assembly 18 provides rearward movement for the seat assembly 8 and / or backrest assembly 6, whether by pivoting, rotating, translating or a combination thereof, for example by a four-bar linkage including links 8, 23, 25 and 33.

[0235] ReferenceFIG. 18 , FIG. 19 and FIG. 21 When the seat assembly 8 tilts or leans backward, the support platform 30 and the load-bearing frame 100 flex or bend around the flexure regions 53 and 153, causing the rear portion 121 of the seat assembly and the rear portion of the support platform to rotate or deflect downward relative to the front portion 123 of the seat assembly and the front portion of the support platform around the flexure regions. Simultaneously, due to the geometry of the seat assembly (including the configuration of the outer ring 104), the geometry of the connector 108, the concavity of the load-bearing frame 100, and the configuration of the openings 109 and 119, the middle connector 108 flexes or bends upward around the flexure region 155, causing the side member 114 of the outer ring 104 to move upward relative to the support platform and the middle connector 108 to move inward toward each other to a new configuration or shape of the side member 114', wherein the textile material 150 presents a more concave configuration of the textile material 150', which is slightly curved and hugs the user. As the connector 108 and outer ring 104 are offset, the total length of the outer ring 104 is maintained and does not increase. It should be understood that the upward movement of the side member 114 is relative to the support platform 30, which can partially move downward, such that the overall or absolute movement of the side member relative to the ground is negligible. The support ring 48 is sufficiently flexible and conformable so that it does not interfere with the flexure of the support frame 100, but rather provides a decorative and tactile skin covering the bottom surface of the support frame. If desired, the support ring 48 may also be provided with flexural areas to allow for such flexure. Due to the geometry of the seat assembly (including the configuration of the outer ring 104), the geometry of the curved connector 108 (e.g., upward concavity), the concavity of the support frame 100, and the configuration of the openings 109, 119, the side member 114 and connector 108 are relatively rigid and resist / avoid downward deformation in response to downward loads applied along the sides of the seat at the perimeter of the chair.

[0236] When the user leans, the back frame 218 tilts rearward together with the rear link 25, and the back support 212 also tilts rearward together with the rear link 25. Simultaneously, and in response to the load applied to the backrest by the user, the back support 212, particularly the lower portion 226 and the upright portion 222, will flex about flexure regions 225 and 231 respectively, while pivoting relative to the back frame 218 via the connector 228. Specifically, the flexure region 225 of each upright portion 222 adjacent to the lumbar region will bend or flex to provide more support at the lumbar region, while the lower flexure region 231 adapts to and allows flexure in the lumbar region. Meanwhile, the connector 228 above the flexure region 225 allows the back support 212, particularly the upright portion 222, to rotate relative to the back frame 210 and the upright portion 218 to adapt to the flexure in the lumbar region.

[0237] Due to the orientation of the front and rear links and the relative positioning of the flexural regions 27 and 53, respectively located above and in front of flexural regions 29 and 31, the four-bar linkage provides a weight-activated system, meaning that the user's weight is taken into account when tilting, as the increase in potential energy is offset by the kinetic energy required for tilting. Thus, the four-bar linkage provides greater resistance for heavier users and automatically balances them. As previously mentioned, the amount of tilt can be limited by a tilt limiter, while energy can be provided to increase tilt resistance and return the body support components to an upright nominal position.

[0238] While the invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes in form and detail may be made without departing from the spirit and scope of the invention. Therefore, the foregoing detailed description should be considered illustrative rather than restrictive, and the appended claims, intended to define the scope of the invention, include all their equivalents.

Claims

1. A body support component, comprising: Base components; The lower support structure includes: A longitudinally extending portion, said longitudinally extending portion being coupled to the base member at a first position; Front link, the front link extending upward from the longitudinal extension portion in front of the first position; and A rear link that extends upward from the longitudinal extension portion behind the first position; A back frame, the back frame including a first lower portion and an upright portion, the first lower portion extending rearward from the rear link, and the upright portion extending upward from the lower portion; A seat support member coupled to the front link and the rear link, wherein the seat support member supports a seating surface; and A back support member, pivotally connected to the upright portion at a second position above the seat surface, wherein the back support member includes a second lower portion spaced apart from a first lower portion and connected to the rear link below the seat support member. Wherein, the longitudinal extension portion and / or the front link defines a first flexure region, wherein the longitudinal extension portion defines a second flexure region adjacent to the rear link, wherein the seat support member and the front link define a third flexure region adjacent to the front link, and wherein the seat support member defines a fourth flexure region adjacent to the rear link.

2. The body support assembly according to claim 1, wherein, The front link comprises a pair of laterally spaced front links.

3. The body support assembly according to claim 1, wherein, The upright portion includes a pair of laterally spaced first upright portions, and wherein the back support includes a pair of laterally spaced second upright portions pivotally connected to the first upright portions.

4. The body support assembly according to claim 3, wherein, The back support further includes an upper member, wherein the upper member and the second lower portion are coupled to the second upright portion and define a central opening, and the body support assembly further includes a suspension member arranged across the central opening and secured to the back support.

5. The body support assembly according to claim 1, wherein, The second lower portion of the back support includes a curved transition portion that is spaced above the first lower portion of the back frame and defines an open lateral passage through the curved transition portion and the first lower portion.

6. The body support assembly according to claim 1, wherein, The first lower portion of the back frame and the lower support structure include an overlapping portion that at least partially defines the rear link.

7. The body support assembly of claim 1, further comprising an armrest assembly, the armrest assembly including a base portion disposed above the longitudinal extension of the lower support structure and coupled to the base member, wherein, The base portion of the armrest assembly includes a pair of lateral extending arms and a pair of upright portions. The pair of lateral extending arms are disposed between the lower support structure and the seat support member and extend outward from the lower support structure and the seat support member. The pair of upright portions are connected to the lateral extending arms and extend laterally along opposite sides of the seat support member.

8. The body support assembly according to claim 7, wherein, The armrest assembly is fixed relative to the base member, and the seat support member is movable relative to the armrest assembly from an upright nominal position to an inclined position.

9. The body support assembly according to claim 1, further comprising a pressure spring disposed between the base and the rear link, the pressure spring biasing the lower support structure from an inclined position to an upright nominal position.

10. The body support assembly according to claim 1, wherein, When viewed from the left side, the back support has an S-shaped profile.

11. The body support assembly according to claim 1, wherein, The back support includes a forward-facing convex bow shape at a third position in the waist region near the back support and a rearward-facing convex bow shape at a fourth position spaced below the third position.

12. The body support assembly according to claim 11, wherein, The lower portion of the back support includes an arm that extends forward in a convex, arched shape from the rearward side, wherein the arm is coupled to the rear link.

13. The body support assembly according to claim 12, wherein, The arm portion includes an upward-folding end portion, and the seat support member includes a boss structure disposed above the rear link and the upward-folding end portion to secure the arm portion to the rear link.

14. A body support component, comprising: Base components; The lower support structure includes: The longitudinally extending portion is coupled to the base member at a first position, and the longitudinally extending portion defines a first flexural region positioned behind the first position. A front link extending upward from the longitudinal extension portion anterior to the first position, wherein at least one of the longitudinal extension portion and / or the front link defines a second flexure region positioned anterior to the first position; and A rear link that extends upward from the longitudinal extension portion behind the first position; A seat support member coupled to the front link and the rear link, wherein the seat support member supports a seating surface, wherein at least one of the seat support member and / or the front link defines a third flexural region, and wherein the seat support member defines a fourth flexural region adjacent to the rear link; A rigid back frame extending upward and rearward from the lower support structure, wherein the rigid back frame is rigidly connected to the rear link; and A flexible back support having an upper portion and a lower portion, the upper portion being pivotally connected to the rigid back frame at a second position vertically spaced above the seat support, and the lower portion being rigidly connected to the rear link, wherein the flexible back support has a fifth flexural region located between the seat support and the second position and a sixth flexural region located between the fifth flexural region and the rear link.

15. The body support assembly according to claim 14, wherein, The upper portion of the back support includes a pair of laterally spaced upright portions, an upper member, and a lower member, the upper member and the lower member extending between and connected to the upright portions, wherein a central opening is defined between the upright portions and the upper and lower members, and the body support assembly further includes a suspension member arranged across the central opening and secured to the upper member, the lower member, and the upright portions.

16. The body support assembly of claim 14, wherein, The first flexural region, the second flexural region, the third flexural region, the fourth flexural region, and the fifth flexural region are defined by the lower support structure and the flexible portion of the back support.

17. The body support assembly according to claim 14, wherein, The back frame includes a pair of first uprights, and the back support includes a pair of second uprights, each of the second uprights being laterally outwardly positioned from one of the first uprights, and the body support assembly further includes a pair of connectors extending between one of the first uprights and one of the second uprights, wherein the connectors pivotally connect the first uprights and the second uprights.

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