具体实施方式：
[0069]It should be understood that the term “plurality,” as used herein, means two or more. As shown in FIG. 1, the term “longitudinal,” as used herein, means of or relating to a length or lengthwise direction 2, for example a direction running from a top to bottom of a backrest 8, or a front to back of a seat 6, and vice versa (bottom to top and back to front). The term “lateral,” as used herein, means situated on, directed toward or running in a side-to-side direction 4 of the backrest or seat. The term “coupled” means connected to or engaged with whether directly or indirectly, for example with an intervening member, and does not require the engagement to be fixed or permanent, although it may be fixed or permanent. The terms “first,”“second,” and so on, as used herein, are not meant to be assigned to a particular component or feature so designated, but rather are simply referring to such components and features in the numerical order as addressed, meaning that a component or feature designated as “first” may later be a “second” such component or feature, depending on the order in which it is referred. It should also be understood that designation of “first” and “second” does not necessarily mean that the two components, features or values so designated are different, meaning for example a first direction may be the same as a second direction, with each simply being applicable to different components or features. The terms “upper,”“lower,”“rear,”“front,”“fore,”“aft,”“vertical,”“horizontal,” and variations or derivatives thereof, refer to the orientations of the exemplary body support structure as shown in FIGS. 1 and 2. The phrase “body support structure” refers to a structure that supports a body, including without limitation office furniture, home furniture, outdoor furniture and vehicular seating, including automotive, airline, marine and passenger train seating, and may include without limitation beds, chairs, sofas, stools, and other pieces of furniture or types of seating structures. The directions X, Y and Z are defined as shown in FIG. 1, with the Z direction being normal to the seat and backrest, the X direction coinciding with the lateral direction 4 of the seat and backrest and the Y direction coinciding with the longitudinal direction 2 of the seat and backrest.
Lattice Structure:
[0070]The term “lattice” refers to a three-dimensional structure having a matrix of nodes 16 and struts/beams/legs 18 extending between and connecting the nodes 16 (see FIG. 30), with the nodes and struts being arranged to provide high-strength and low mass mechanical properties, which provides significant weight reductions while maintaining a requisite overall structural integrity. The lattice structure provides excellent ventilation and air circulation properties. Various components of a body support structure 32 may include regions that are latticed, while other regions may remain solid, or non-latticed, as further explained below.
[0071]The core unit 12 of the lattice, or cell, shown for example in FIG. 19, may be repeated to define the overall lattice structure. Some exemplary cell structures are cubic, star, octet, hexagonal, diamond and tetrahedron. The cell structures may be individually varied or tuned and integrated or mixed to achieve the desired response, shape and overall performance of the lattice structure. Some cell structures may have higher stiffness-to-weight ratios while others may provide other properties, such as the ability to absorb or dampen energy. Cell size and density refer to the size of an individual unit cell and how many cells are repeated within a space. The size of the cell is a function of the dimensions (e.g., thickness and length) of the nodes and beams/legs. The material and density of the lattice structure, along with the orientation of the cells and structure, may have an effect on the properties of the lattice. The intrinsic structural properties of the lattice are determined by the architecture of the unit cell, including the dimensions and shape of the legs, the overall size of the cell and the density of the cells. In a preferred embodiment, the lattice structure conforms to the shape of the structure, meaning the orientation of the cells may change to accommodate the intended properties. For example, a compressive lattice structure is oriented to provide compressibility in the vertical direction in a seat region, but is oriented to provide compressibility in the horizontal direction in the backrest direction, such that the loads are absorbed in the Z direction of the seat and backrest. In this way, the orientation of the lattice structure conforms to the shape of the seat/backrest, and changes as the lattice structure fills the arbitrary geometric shape. The lattices are thereby aligned with the load/stress directions, which improves the overall structural performance of the structure.
[0072]The inherent complex nature of lattices makes them ideally suited for additive manufacturing, which may be performed for example by 3-D printing. Some exemplary 3D printing technologies include Fused Deposition Modeling (FDM), Stereolithography (SLA), Digital Light Processing (DLP), Selective Laser Sintering (SLS), Selective Laser Melting (SLM), Electron Beam Melting (EMB), Laminated Object Manufacturing (LOM), Binder Jetting (BJ), Digital Light Synthesis (DLS), Multi Jet Fusion (MJF), Digital Light Synthesis (DLS), Multi Jet Fusion (MJF) and Material Jetting/Wax Casting.
[0073]As shown in FIG. 30, for example, a compressive lattice structure may incorporate three intersecting and orthogonal rectangles 16, 18, 20 that define nodes 22 at four corners of a first rectangle 18 and a pair of nodes 26 at the intersection of the other two rectangles 16, 20, with a pair of beams 24 extending between each of the corner nodes 22 and the pair of nodes 26. Referring to FIG. 20, a core unit with a face further includes a pair of nodes 28 arranged along two corners of one of the other rectangles 16, with beams 30 extending between the corner nodes 22, 28.
Body Support Structure
[0074]Referring to the drawings, FIGS. 1-17 and 29show one embodiment of a body support structure 32, configured as a chair having a base 34, a seat 6 and a backrest 8. The base 34 includes a pedestal 36 having a bottom platform 38 that engages a floor 40 and an upright 42 extending upwardly from the platform 38. The platform 38 has a generally horizontal orientation, with a front edge 44 that tapers rearwardly from a centerline apex 46. In one embodiment, the front edge defines the forwardmost boundary or surface of the body support structure, while in another embodiment, a front edge 48 of the seat 6 defines a forwardmost boundary of the body support structure. The upright 42 includes a lower portion 50 that extends rearwardly and upwardly from the front edge 44, and an upper portion 52, that extends forwardly and upwardly from the lower portion 50. The lower portion has a first width (W1) adjacent the front edge and a second width (W2) adjacent a junction 54 with the upper portion, with the second width (W2) being less than the first width (W1). Both the lower and upper portions have a front surface that tapers rearwardly from a front centerline YZ plane 101, such that the upper and lower portions have a generally triangular cross-sectional shape. The taper of the front surface of the lower portion 50 and front edge 44 provide increased access for the user's feet and legs. At the same time, the cross-sectional shape of the upright, with the protruding centerline apex 58, provides increased resistance to bending about a horizontal, laterally extending X axis. The upright and base define a general L-shape from a side view, which creates an open space beneath the seat 6.
[0075]A seat support 60 is connected to the base along a top end 68 of the upper portion 52 of the upright 42. The seat support includes a pair of spaced apart beams 62 defining an opening 148 therebetween, and a pair of U or V shaped connectors 64 connecting forward portions 66 of each beam with the upper portion 52. The connectors 64 may flare outwardly and define a first flex region 210 or compliant joint, allowing the beams 62, which are rigid and resistant to bending, to pivot relative to the base 34 (and the upright 42 in particular) about a horizontal, laterally extending X axis. The beams 62 of the seat support are cantilevered rearwardly from the connectors 64 and flex region 210.
[0076]A back frame 70 is connected to the seat support along rear portions 72 of the beams 62 and extends upwardly from the seat support 60, with the back frame 70 having a pair of laterally spaced uprights 74 defining an opening 150 therebetween, and an upper cross member 76 connecting the upper ends of the uprights 74. The uprights 74 are connected to the rear portions 72 of the beams with a curved transition region 78, which defines a second flex region 212, or compliant joint, allowing the back frame 70 to pivot relative to the seat support 60. As shown in FIGS. 2, 4, 8 and 10, an upper portion 80 of the uprights and the cross member 76 have a greater width and thickness, such that those portions are more rigid than lower portions 82 of the uprights. The interface between the upper and lower portions defines a recess 84 having a depth (D1), which is filled with a compressive layer, which lies flush with the front surface of the uprights 74, as further explained below.
[0077]Referring to FIGS. 1-4, 8, 9, 16, 17 and 36, a strut 86 is disposed, or extends, between the base 34 and one of the seat support 60 and/or back frame 70, including the transition region 78. The strut includes a lower portion 88 and an upper portion 90. As shown in FIG. 3, a lower end 92 of the strut, or lower portion thereof, is connected to the upright at the junction 54 between the upper and lower portions of the upright, with the strut 86 angled at an angle α, which is generally the same orientation as the lower portion 50 relative to the platform 38, or a horizontal plane defined by the floor, such that axial loads applied by the strut 86 are efficiently transferred to the lower portion 50 and then to the platform 38. An upper end 94 of the strut, or upper portion thereof, is connected to the seat support 60, and in particular to the spaced apart beams 62 forwardly of the transition region 78. The strut is generally monolithic and extends along a centerline of the body support structure, although it should be understood that is may be configured as two or more laterally spaced struts connected to the beams respectively. The strut 86 spans the distance between the beams 62, thereby providing lateral stability to the beams, while also supporting a rear region of the beams 62 spaced longitudinally rearwardly from the flex region 210 defined by the connectors 64. The upper and lower portions 88, 90 of the strut are spaced apart, with one of the upper and lower portions having a post or guide member 96 extending into a channel or track 98 defined in the other of the upper and lower portions. The respective ends of the upper and lower portions facing each other may be configured with a cap, or other bearing surface 104, 106.
[0078]A use interface member 144 is secured across the openings 148, 150 defined between the beams 62 of the seat support and the uprights 74 of the back frame to define a seating surface of the seat 6 and backrest 8.
Structural Lattice Structure
[0079]Each of the base 34, strut 86, seat support 60 and back frame 70 may be formed entirely, or at least partially, from a structural lattice structure 108. The structural lattice structure is a bending resistant structure that is relative stiff, while a compressive lattice structure is a non-bending resistant structure, which is compliant and, although not stiff, absorbs energy well when compressed. The structural lattice structure has a first stiffness, which is the displacement measured along a degree of freedom (translationally or in bending) in response to an applied force. The stiffness is determined, or defined by, the lattice architecture and materials, for example the overall moment of inertia of the component or cross-section thereof, and the Young's modulus of elasticity associated with the material. When a lattice structure is loaded, whether in compression or bending, the structural lattice structure may undergo some elastic deformation, but remains relatively rigid except at predetermined flex regions, which are purposefully designed to allow for bending and flexing. The structural lattice structure is also conforming, meaning the architecture and orientation of the cells and lattice follows or conforms to the arbitrary external geometry of component, and is optimized to align with the stresses and loads applied to the structure.
[0080]As shown in FIGS. 1-6, the structural lattice structure 108 defining the platform, and portions of the lower and upper uprights 50, 52, follow a lateral gradient in the lateral direction 2, with the lattice structure being very open with larger spaces between the nodes along the centerline plane 101 of the upright and platform, and a more closed architecture, with smaller spaces between the nodes, along the side edges 103 and rear edge 105 of the platform, and along the side edges 107 of the upright 42, with the size of the cells gradually decreasing along the gradient. Solid (non-lattice) sections may also interconnect lattice sections, with the solid (non-lattice) section locations providing additional strength, or are located such that various components may be separately manufactured, for example by 3D printing, and then later assembled and connected. The solid (non-lattice) sections may contain attachment geometries, and may be configured with internal lattice structures surrounded by solid outer walls.
[0081]In one embodiment, as shown in FIGS. 1-5, 8-10 and 13-15, non-lattice structures 64, 100, 102 are positioned between portions of the structural lattice structure such that the structural lattice structure is discontinuous, for example with non-lattice structure 100 disposed between the structural lattice structure of the upper and lower portions 50, 52 of the upright even though the component is a single homogenous, integrally formed unit. Specifically, the base platform 38 and portions of the lower and upper portions 50, 52 of the upright are made from a structural lattice structure, while a non-lattice structure 100 defines the transition region between the upper and lower portion of the upright, and between the upright and the lower end of the strut, as well as the bearing surfaces 104, 106, guide 96 and track 98. Likewise, the connectors 64 may be made of a non-lattice structure, as well as the joint or transition 102 between the upper end of the strut and the seat support beams, as well as portions of the beams 62. The non-lattice structure is stronger than the structural lattice structure, and is ideally suited for the various joints interfacing between the components that may experience high loads and stresses due to bending. The non-lattice structure may include a solid or tubular structure, including for example one or more central openings with a surrounding peripheral wall. In one embodiment, the structural lattice structure and non-lattice structures have the same outermost profile, with the outmost surfaces thereof lying flush. The structural lattice structure and non-lattice structure may be made of the same materials and as a single, one-piece homogenous part, for example by additive manufacturing, including 3-D printing as further explained below. In one embodiment, the structural lattice structure is made of polyethylene, or other relatively stiff materials such as metal. Other materials include thermoplastic elastomers, such as TPE and TPU. In one embodiment, the structural lattice structure is made of 30% GF Nylon, with a Young's modulus of 700 ksi or more. The structural lattice structure, and/or the non-lattice structure, provide for isolated compliance, or are configured to provide specific flex zones/compliance joints to allow for movement between components, for example between the seat and base, or between the backrest and seat, while remaining rigid and stiff in other regions and areas. The structural lattice structure may include a core unit and a core unit with a face along the outermost surfaces thereof as shown in FIGS. 30 and 31, with the orientation of the core unit arranged such that the structural lattice structure is stiff and oriented to carry the loads applied thereto, for example with properties similar to an injection molded component.
Compressive Lattice Structure:
[0082]Referring to FIGS. 1-12, and 16, the seat 6 and backrest 8 further include a first compressive member 110 having a pair of laterally spaced beams 114 overlying and supported by the seat support beams 62, a pair of laterally spaced uprights 116 extending transverse to the beams 114 and upwardly along a front surface of the back frame uprights 74, and a front cross member 118 extending laterally between the front ends of the beams 114 proximate the front of the seat. In this way, the compressive member has a lower U-shaped portion a pair of uprights extending upwardly from the lower portion and defining a generally forklift carriage shape with tines defined by the uprights 116. The uprights 116 fill the recess 84 formed by the back frame uprights and provide a flush surface with the upper portion 80 of the back frame 70.
[0083]Referring to FIGS. 1-4, 16-19 and 36, a second compressive member 120 is disposed between the upper and lower portions 88, 90 of the strut, and has upper and lower surfaces 122, 124 abutting the bearing surfaces 104, 106. The second compressive layer has a central through opening 126, through which the guide 96 is disposed.
[0084]The first and second compressive layers are made of a compressive lattice structure 112, which is supported by (or between) the structural lattice structure(s) and/or solid structures as described above. The compressive layer has a second stiffness that is less than the first stiffness, meaning the compressive layer will experience or undergo a greater amount of displacement or deflection in at least one direction in response to the same force applied to a same sized sample of material in the at least one direction. In some embodiments, the first stiffness is many times greater than the second stiffness. In some embodiments, the second stiffness is 50%, or less, of the first stiffness. The stiffness may be varied, for example with the lattice structure being more compressible, by altering the orientation of the lattice structure such that the long side of the diamond cell structure (FIG. 30) is perpendicular to a load FN, which is perpendicular to the surface. In other words, the stiffness is a function of the load direction and lattice orientation, the dimensions of the lattice structure (e.g., diameter of the beams), the voxel density (node density), in combination with the Young's modulus of elasticity associated with the material making up the lattice structure. Some exemplary materials are thermoplastic polyurethane (TPU), and may have a Young's modulus of 200 ksi or less, and in one embodiment 100 ksi or less, with the compressive lattice structure having compressive properties similar to some foams. The compressive lattice structure provides distributed compliance. The compressive lattice structure is compressible in response to the normal force FN being applied thereto, for example as applied by the upper and lower bearing surfaces 104, 106 of the strut, or by a user sitting on the seat as shown in FIGS. 4, 8 and 16. As shown in FIGS. 1-12, and 16, the compressive lattice structure, for example the beams, includes a cellular matrix having a first portion 126 having one or more layers of unit cells and a second portion 128 having a plurality of layers of unit cells, with the second portion having more layers of unit cells than the first portion, and including a transition region 130 between the first and second portions. For example, a forward portion of the beams, and the cross member, has a greater number of layers, and thereby provide a greater amount of compressive displacement in response to a normal load being applied thereto.
[0085]Referring to FIGS. 1-4, 16-19 and 36, the second compressive member 120 functions as a spring, which is compressed as a user sits and reclines in the chair, with the upper and lower strut portions 88, 90, which are configured from a structural lattice structure and/or solid component, compressing the spring between the bearing surfaces as the guide 96 moves within the track 98. The second compressive member provides a biasing force to resist the recline of the seat, and biases the upper and lower portions of the strut away from each other to return the seat to a nominal position when not loaded. In particular, the second compressive member, which is defined by an intermediate compressive lattice structure, is connected to the first and second end portions of the upper and lower portions 88, 90 of the strut, which are relatively stiff, with the first and second end portions being moveable between a nominal position and a compressed position. The intermediate compressive lattice structure is compressible between a nominal configuration and a compressed configuration corresponding to the nominal and compressed positions, wherein the intermediate compressive lattice structure applies a biasing force to the first and second end portions when in the compressed configuration. The strut will also provide a maximum recline/rearward tilt position as the second compressive member reaches maximum compression and bottoms out between the bearing surfaces 104, 106.
[0086]In this way, the strut 86, including the second compressive member 129, has an integrated kinematic feature, which is defined as a feature that effects or controls the motion of a body, or systems of bodies, including for example and without limitation, biasing two or more bodies toward or away from each other, limiting movement between two or more bodies, and/or locking two bodies in one or more relative positions. It should be understood that the integrated kinematic feature may include one or both of, or be formed from one or more of, a structural lattice structure, a solid structure, a compressive lattice structure, and/or a skin lattice structure, discussed below.
[0087]The lattice structures may include various integrated kinematic features, such as the second compressive member 120, which acts as a biasing member. Alternatively, and referring to FIGS. 33 and 34, the integrated kinematic feature may include a movement limiter, for example a tilt limiter, with a compressive member 134 (lattice structure) that bottoms out when adjacent lattice structures 136, 138 abut (FIG. 34), or when an extensible lattice structure (same as compressive but expanding in response to a tensile force) reaches a maximum extension. Such integrated kinematic features may be of any lattice structure, including the structural and compressive lattice structures defined herein.
[0088]In another embodiment, shown in FIG. 33, the lattice structure may include interlaced lattice features 140, such as loops having stops 142, which are moveable relative to each other, with the lattice features moving relative to each by translation, rotation or torsion until the stops 142 are engaged, which prevents further movement, or thereby provides a movement limiter. The integrated kinematic feature may also include lattice structures, such as the stops, which engage or lock the lattice structures in a predetermined position, or fasteners such as tabs, hooks and/or guides, which may secure one lattice structure or component to another.
[0089]The compressive lattice structure may include a core unit and a core unit with a face along the outermost surfaces thereof as shown in FIGS. 30 and 31.
Skin Lattice Structure
[0090]Referring to FIGS. 1-7, 20-29 and 37-49, a user interface member 144, 344, otherwise referred to as a skin member, is connected to the upper and front surfaces of the compressive member 110 and to the front surface of the upper portion 80 of the back frame. It should be understood that a cover may be positioned over the user interface layer in an alternative embodiment, for example an upholstery fabric, and may include a foam layer disposed between the cover and the user interface member. The skin member 144, 344 spans across the openings 148, 150 between the beams and between the uprights and forms a seat member 201 and back member 203, with a concave transition region 205 therebetween, that define a seating surface. As shown in FIG. 37, the skin member 344 may be coupled to a non-lattice frame, for example a seat frame 360 or a backrest frame 362, either of which may include laterally spaced opposite side members 364 (uprights 366 on the backrest) and longitudinally spaced front and rear members (top and bottom members on the backrest), with the side/upright, front/bottom and rear/top members forming a ring. The skin members 344 may alternatively be secured to only the side (upright) members, only the front (bottom) and rear (top) members, the side/upright, front/bottom and rear/top members or any combination of the members. In the embodiment shown, separate seat and backrest skin members are attached to the seat and backrest frame respectively. The skin member 144, 344 is made of a skin lattice structure 146, which is resistant to shear deformation in response to a normal load FN being applied thereto. As such, the skin lattice structure may absorb the weight of the user and carry it across the openings 148, 150 to the spaced apart beam members 62, 114, 364 and/or spaced apart uprights 74, 116, 366. At the same time, the skin lattice structure is expandable in the lateral X and longitudinal Y directions transverse to the second normal force, which is applied in the Z direction, such that the skin lattice structure can deflect while carrying the load applied by the user to the beams and uprights. At least a portion of the skin lattice structure overlying the opening 148 between the laterally spaced beams, and the opening 150 between the laterally spaced uprights, is not supported by any other structure.
[0091]Referring to FIGS. 20-29 and 37-49, the skin lattice structure includes first and second layers 152, 154 connected with a plurality of connectors 156. In one embodiment, the skin lattice structure includes a plurality of spaced apart support members 158, which face toward the body of the user, and a plurality of spaced apart base members 160, which face away from the user, with the plurality of connectors 156, or legs, connecting the support members and base members. The first layer 152 includes the plurality of support members 158 defining opposite first and second surfaces 162, 164 facing toward and away from the body of the user. Adjacent support members define openings 166 between sides of the adjacent support members.
[0092]The second layer 154 includes the plurality of spaced apart base members 160 defining opposite first and second surfaces 168, 170 facing toward and away from the body of the user. The first surfaces 168 of the base members face toward and are spaced apart from the second surfaces 164 of the support members such that the plurality of support members and the plurality of base portions define a space 174 therebetween. Each of the base members 160 underlies at least portions of the openings 166 defined by at least two (and preferably 3 or 4) adjacent support members 158, and also underlies portions of the adjacent support members 158. Adjacent base members define openings 176 between sides of the adjacent base members. Portions of the openings 176 underlie portions of the openings 166, which provides for through openings 181 extending through an entirety of the skin lattice structure between the sides of the base members and the sides of the support members. The plurality of connectors 156 extend across the space and connect each base member 160 with the at least two adjacent support members 158, for example at respective corners of each of the support members and base members. The support members and base members are offset from each other ½ unit in both the X and Y direction. In one embodiment, each connector 156 defines a first acute angle ⊖1 relative to the second surface of the respective support member and a second acute angle ⊖2 relative to the first surface of the base portion, with ⊖1 and ⊖2 being equal in one embodiment. The connectors are angled away from a corner and toward a centerline of the respective support member and base member to which they are attached, forming an angle β (e.g., 45 or 135 degrees) with a side edge of the support member and/or base member. By orienting the connectors at an angle toward a centerline, the space between support members, or width of the openings 166, and the space between the base members, or width of the openings 176, may be minimized, which provides as continuous surface 168 as possible while allowing debris to pass though the openings 166, 176. For example, the width of openings 166 and 176 may be equal to or greater than 0.5 mm. In addition, the connectors 156, when angled, are longer than a connector extending normal to the base and support members at a specified gap. The longer connector 156, in combination with the angle, may provide for increased flexibility of the connector and resulting flexibility/expandability of the skin member 144, 344. The skin member with angled connectors may be formed by additive manufacturing techniques. Conversely, when the connectors 156 extend substantially normal (e.g., perpendicular) to the base and support members, as shown in FIG. 39, the skin member 344 may be more easily manufactured by conventional molding techniques, for example injection molding.
[0093]The skin lattice structure 146 provides distributed compliance. The connectors 156 are resilient and elastically deformable to allow relative movement between the connected support members 158 and base members 160. For example, the skin lattice structure may be compressed and expanded within the surface (e.g., plane) in response to translation forces (created by application of the normal force), such that the seating structure exhibits flexibility within the plane of the array, with the understanding that the surface may be curved for example in two directions as a saddle shape, or one direction as a bow shape, such that the translation forces are tangential to the surface at any particular location. In particular, the connectors 156 elastically deform to provide for the relative expansion/compression. The compression or expansion may take place simultaneously in the longitudinal and/or lateral directions, or in other directions depending on the arrangement of the array including the connectors. The deformation of the connectors may be realized through one or both of the geometry and/or material of the connectors.
[0094]The skin lattice structure 146 may also be flexible, or experience bending and or torsion/twisting deformation in response to bending forces and twisting forces. The bending and twisting may take place simultaneously about various longitudinal and/or lateral axes (lying within or tangential to the curved surface), or about other tangential axes depending on the arrangement of the array including the connectors. In contrast, the skin lattice structure is relatively stiff, and resists deformation, in response to shear forces FN, applied for example normal or perpendicular to the curved surface. The skin lattice structure 146 may be made of a stiffer material than the compressive lattice structure, for example from a polypropylene or a stiff TPU, with a Young's modulus of 200-300 ksi in one embodiment, or greater than the modulus of the compressive lattice structure and less than the modulus of the structural lattice structure.
[0095]The phrase “elastic,” or “elastically deformable,” and variations or derivatives thereof, refers to the ability of a body, e.g., connector, to resist a distorting influence or stress and to return to its original size and shape when the stress is removed. In this way, the connectors 156 preferably do not experience any plastic (e.g., permanent) deformation. The support members and base members may also experience some elastic deformation, although the primary deformation or deflection,