WO2008121754A1

WO2008121754A1 - Foam reinforced vehicular seating system

Info

Publication number: WO2008121754A1
Application number: PCT/US2008/058557
Authority: WO
Inventors: Henricus J. Koelman; Gerhardus Z. Slik
Original assignee: Dow Global Technologies LLC
Current assignee: Dow Global Technologies LLC
Priority date: 2007-03-30
Filing date: 2008-03-28
Publication date: 2008-10-09
Anticipated expiration: 2009-09-30

Abstract

The present invention is premised upon the development of an improved automotive vehicle seat back assembly having a molded plastic seat back including a first wall portion (20) and an opposing second wall portion (22) (which wall portions may or may not be integrally formed), one or more integrated reinforcement structures (24) disposed there between and a foam material (26) disposed between the first (20) and second wall (22) in preselected areas.

Description

FOAM REINFORCED VEHICULAR SEATING SYSTEM

Claim of Benefit of Filing Date

The present application claims the benefit of the filing date of U.S. Provisional Application Serial No. 60/909.119, filed March 30, 2007, hereby incorporated by reference.

FIELD OF THE INVENTION

[001] The present invention relates to an improved seating system, and more particularly to an improved system for automotive vehicle seating.

BACKGROUND

[002] Efforts to improve vehicle seat backs have received increased attention in recent years in view of more rigid governmental standards for cargo retention. The ability to address this need with a cost effective and generally lightweight material selection has resulted in a number of seat back developments as exemplified in U.S. Patent Nos. 6,491 ,346; 6,688,700; 6,739,673; 6,997,515, 7,128,373 and 7,137,670; incorporated by reference. Notwithstanding these advancements, there remains a desire to present alternative solutions for various applications.

SUMMARY OF THE INVENTION

[003] The present invention is directed to one such solution, and particularly is directed to a molded plastic seat back having a first wall portion, an opposing second wall portion, and one or more foam reinforcement structures disposed between the opposing wall portions. An assembly is provided for receiving the seat. One potential advantage of the present invention is the ability to employ plastics heretofore regarded as less practical for seat back applications that require more stringent loading requirements, such as polyolefin and polyethylene. Additionally, the invention affords the ability to selectively improve local properties and reduce wall thickness and section thickness. Advantageously, the seating system upon rapid acceleration up to about 20 to about 30 g or even up to 50 g, there is no fragmentation of the seat back with at least a 20 Kg mass placed behind the seat back. The system is easy to manufacture and will not add substantial weight to the vehicle as compared with other commercial seating systems.

[004] Accordingly, pursuant to one aspect of the present invention, there is contemplated a seating assembly for an automotive vehicle, that may include a blow molded plastic seat back having a forward wall portion and a rearward wall portion, and a plurality of foam channels with a foam disposed therein, and a plurality of integrated reinforcement structures for defining an integrated reinforcement structure pattern; a hinge assembly having a bracket portion including a first side wall portion, an opposing second side wall portion, the walls adjoined to the seat back and a pivot member for hingedly anchoring the seat back directly to a first body in white portion of the automotive vehicle; and a latch secured to a second body in white portion of an automotive vehicle; and a striker having a projecting striker bar attached to a mounting portion in overlapping engagement with the rearward wall portion of the seat back for interferingly engaging the latch to maintain the seat back in a generally upright position. [005] The invention may be further characterized by one or any combination of the features described herein, such as the bracket may be deposed over a foam channel in the seat back. An intermediate wall portion of the bracket may connect the first wall section to the second wall section, including a section terminating at an edge that extends beyond a first distal end of the first side wall portion and toward a second distal end of the second side wall portion. The mounting portion of the striker may include at least one flange for overlapping and engaging the blow molded plastic seat back. The striker may be disposed long a top edge portion of the blow molded seat back, disposed along a side edge portion of the blow molded seat back, or disposed in an upper corner of the blow molded seat back. The seat back may be fabricated in a single blow molding operation. The first and second wall portions of the seat back may be fabricated separately and joined thereafter. The foam may be introduced to foam channels after the formation of the foam channels. At least a portion of the foam may be introduced to the foam channels prior to joining the first and second wall portions. [006] Accordingly, pursuant to another aspect of the present invention, there is contemplated a seating assembly for an automotive vehicle, that may include a seat back formed from a molded polypropylene plastic having a forward wall portion and a rearward wall portion, a plurality of polyurethane foam channels; and an attachment assembly having a bracket portion including a first side wall portion, an opposing second side wall portion, the walls adjoined to the seat back, anchoring the seat back to a first body in white portion of the automotive vehicle; wherein the seating assembly is capable of exhibiting at least one response selected from (1) withstanding without rupture at least about 11000 Newtons in the direction in which the seat faces in a plane, parallel to the longitudinal centerline of the vehicle; (2) upon rapid acceleration up to at least about 20 g, substantially no fragmentation of the seat back with at least a 20 kg mass placed behind the seat back; or (3) a combination of both responses (1) and (2). [007] Accordingly, pursuant to another aspect of the present invention, there is contemplated a foldable automotive vehicle seating system, that may include a molded thermoplastic seat back including a first wall portion and an opposing second wall portion and one or more foam channels disposed therebetween; a hinge assembly for pivotally anchoring the seat back to an automotive vehicle, including a receiving portion for securing the seat back to the hinge assembly, and a mounting portion for securing the hinge assembly to the vehicle; and a self locking releasable retention mechanism for maintaining the seat back in a generally upright position, wherein the seating system is capable of withstanding without rupture at least about 13000 Newtons in a direction in which the seat faces in a plane, parallel to the longitudinal centerline of the vehicle, and exhibits, upon rapid acceleration up to about 20 to about 3O g, no fragmentation of the seat back with at least a 20 kg mass placed behind the seat back. [008] The invention may be further characterized by one or any combination of the features described herein, such as the thermoplastic may include a polycarbonate material, a styrenic material, or a mixture thereof. The thermoplastic may include a polyester. The thermoplastic may include a polyamide. The thermoplastic may include a polyolefin. A reinforcement inserted in a space between the first wall portion and the second wall portion. At least one of the foam channel walls may be a single rib member that extends between the first wall portion and the second wall portion. The seat back may be fabricated in a single blow molding operation. The first and second wall portions of the seat back may be fabricated separately and joined thereafter. May include a shoulder belt mounted to the seat back. The retention mechanism may be located along a side of the seat back, the top of the seat back or a combination thereof. The foam may be introduced to foam channels after the formation of the foam channels. At least a portion of the foam may be introduced to the foam channels prior to joining the first and second wall portions. The seating assembly may be capable of exhibiting at least one response selected from (1) withstanding without rupture at least about 13000 Newtons in the direction in which the seat faces in a plane, parallel to the longitudinal centerline of the vehicle; (2) upon rapid acceleration up to at least about 20 to about 30 g, substantially no fragmentation of the seat back with at least a 20 kg mass placed behind the seat back; or (3) a combination of both responses (1) and (2). [009] Accordingly, pursuant to another aspect of the present invention, there is contemplated a seating assembly for an automotive vehicle, that may include a forward wall portion; a rearward wall portion created separately from the first portion, wherein the forward wall portion and rearward wall portion comprise dissimilar materials; at least one interface between the forward wall portion and rearward wall portion wherein the first wall and second wall are joined; further wherein the first portion and the second portion are defined to include a plurality of individual integrated reinforcement structures; and further wherein the first portion and the second portion includes one or more foam channels with a foam disposed therein; a hinge assembly having a bracket portion including a first side wall portion, an opposing second side wall portion, the walls adjoined to the seat back and a pivot member for hingedly anchoring the seat back directly to a first body in white portion of the automotive; a latch secured to a second body in white portion of an automotive vehicle; and a striker having a projecting striker bar attached to a mounting portion in overlapping engagement with the rearward wall portion of the seat back for interferingly engaging the latch to maintain the seat back in a generally upright position.

[0010] The invention may be further characterized by one or any combination of the features described herein, such as wherein at least a portion of the foam may be introduced to the foam channels prior to joining the first and second wall portions. The seating assembly may be capable of exhibiting at least one response selected from (1) withstanding without rupture at least about 13000 Newtons in the direction in which the seat faces in a plane, parallel to the longitudinal centerline of the vehicle; (2) upon rapid acceleration up to at least about 20 to about 30 g, substantially no fragmentation of the seat back with at least a 20 kg mass placed behind the seat back; or (3) a combination of both responses (1) and (2).

[0011] Accordingly, pursuant to another aspect of the present invention, there is contemplated a method of manufacturing a seating assembly for an automotive vehicle that may include some or all of the steps of: forming a forward wall portion; forming a rearward wall portion; joining the forward and rearward wall portions; introducing a foam into a plurality of foam channels deposed between the first and second wall portions; joining a hinge means to the front wall portion, wherein the hinge means at least partially overlaps at least one of the foam channels; and joining a latching means to the rear wall portion, wherein the latching means at least partially overlaps at least one of the foam channels.

[0012] Accordingly, pursuant to another aspect of the present invention, there is contemplated a method of manufacturing a seating assembly for an automotive vehicle that may include some or all of the steps of: integrally forming a forward wall portion and rearward wall portion, wherein there is a plurality of open channels deposed between the first and second wall portions; introducing a foam into at least one of the plurality open channels deposed between the first and second wall portions; joining a hinge means to at least one of the wall portions, wherein the hinge means at least partially overlaps at least one of the channels, further wherein foam has been introduced; and joining a latching means to at least one of the wall portions, wherein the latching means at least partially overlaps at least one of the channels, wherein foam has been introduced.

DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a perspective view of an illustrative seatback assembly according to the present teaching.

[0014] FIG.1A is a sectional view through the illustrative seatback assembly of FIG.1 according to the present teaching.

[0015] FIG. 2 illustrates a sectional view of an illustrative seatback assembly according to the present teaching.

[0016] FIG. 3 A-F is a plan view of an illustrative seatback panel according to the present teaching.

[0017] FIG. 4 is a perspective view of an illustrative multi-component seatback assembly according to the present teaching.

[0018] FIG. 5 illustrates a sectional view of the seatback in FIG. 4.

[0019] FIG. 6 is a perspective view of an illustrative seatback assembly according to the present teaching.

[0020] FIG.7 is a section view through the illustrative seatback assembly of FIG.6 according to the present teaching. [0021] FIG.8 is a section view through the illustrative seatback assembly of FIG.6 according to the present teaching.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] Referring to FIGS. 1 and 2, the present invention is premised upon the development of an improved automotive vehicle seat back assembly having a molded plastic seat back including a first wall portion 20 and an opposing second wall portion 22 (which wall portions may or may not be integrally formed), one or more integrated reinforcement structures 24 disposed there between and a foam material 26 disposed between the first 20 and second wall 22 in critical areas. A hinge assembly is employed for pivotally anchoring the seat back to an automotive vehicle. The hinge assembly includes a receiving portion for securing the seat back to the hinge assembly, and a mounting portion for securing the hinge assembly to the vehicle. A retention mechanism is employed for maintaining the seat back in a generally upright position. The hinge assembly, retention mechanism or a combination of the two effectively define an assembly for attaching the seat back to the vehicle and anchoring it to one, two, or more body in white portions of the vehicle. Body in white or BIW refers to the stage in automotive design or manufacturing in which the car body sheet metal (including doors, hoods, and deck lids) has been assembled or designed but before the components (chassis, motor) and trim (windshields, seats, upholstery, electronics, etc.) have been added. Seat back configurations of the type described are illustrated, without limitation, in U.S. Patent Nos. 6,491 ,346; 6,688,700; 6,739,673; 6,997,515, 7,128,373 and 7,137,670. Additionally, this invention can be used in vehicular seat backs that are fixed and not foldable, where the seat back is attached directly to the body in white in at least two fastening locations.

[0023] As used herein, and illustrated in FIG. 2, by reference to an exemplary molded section, the phrase "wall stock thickness" or "wall thickness" shall refer to the dimension (T_w) between a first surface and a second surface of a wall, such as first wall 20. Moreover, the phrase "part section thickness" or "section thickness" (T₈) shall refer to the dimension between the first surface of the first wall 20 and an outwardly disposed surface of a second wall 22, if cut by an intersecting plane.

The phrase "foam channel" shall refer to a location where, as shown in FIG. 2 and FIG. 5 the first wall 20 and second wall 22 of a molded component are joined on a first side and a second side to effectively create a hollow channel section that receives a foam filling for creating a locally modified bending moment or otherwise imparting additional rigidity, toughness or impact resistance to a seat back assembly. Foam channels may include substantially straight portions one or more arcuate portions or a combination of each.

[0024] The phrase "integrated reinforcement structure" 24 shall refer to a location where, as shown in FIG. 2 the first wall 20 and second wall 22 of a molded component are joined or enlarged or reduced in wall thickness, section thickness, or otherwise configured to effectively create a beamed structural section for creating a locally modified bending moment or otherwise imparting additional rigidity, toughness or impact resistance to a seat back assembly. Additionally, these reinforcement structures 24 can serve as a separation means for sections of the seat back that have foam filling and those which do not, effectively subdividing the seat back into a plurality of discrete chambers, each of which differ from an adjoining on in one or more characteristics such as geometry of the cross section and depth, width and height of channel created. [0025] The present invention contemplates the use of at foam channels, at least partially filled with a foam, in combination with integrated reinforcement structures for imparting additional rigidity, toughness or impact resistance to a seat back assembly, or otherwise locally modifying the bending moment of a structure. While a variety of structures may be employed for this purpose, the most preferred structures are selected from a rib, tack-offs or a combination thereof plus one or more foam channels, preferably at least partially filled with a foam as taught herein.

[0026] Additionally, in one preferred embodiment in which the seat back substrate is blow molded, the cavity formed between the first 20 and second wall 22 of the blow molded part is injected with foam and substantially filled with the foam and does not require any integrated reinforcement structures.

[0027] Advantageously, in another preferred embodiment, the seat back is made by molding and preferably by blow molding for forming a plurality of hollow foam channels and integrated reinforcement structures during the molding process. Foam is introduced into one or more of the resulting foam channels. By way of illustration, a seat back substrate is fabricated by blow molding, pursuant to which a parison is placed in a cavity of a first tool adapted for defining the shape of a seat back. The parison is heated to a suitable temperature (e.g., for the preferred materials described hereinafter) from about 100⁰C. to about 400⁰C, and more preferably about 130°C. to about 300⁰C. to induce plasticity. A gas is injected into the parison to cause expansion of the parison within the tool cavity and the formation of generally opposing spaced apart first 20 and second wall 22 portions. At or after the expansion occurs and while the material remains in its plastic state, the first or optionally a second tool is brought into contact with one or both of the walls and deforms each contacted wall in the direction of the opposing wall. In one embodiment, the opposing walls remain spaced from each other. In a more preferred embodiment, the walls are brought into contact with each other and remain in contact by this deformation step, thereby forming a tack-off. It will be appreciated that the effect of forming each tack off is to form a structure having wall portions that project away (e.g., as ribs) from the wall portions from which they are formed. After forming the seat back via the above process, foam is introduced into the cavity or foam channel between the first 20 and second wall 22 via openings in either wall. These openings may be formed during the molding process or alternatively via a secondary punching or drilling operations. The foam 26 could be placed within the cavity either during the blow molding process or as a secondary operation post-molding at the press location or any site remote from the press.

[0028] Advantageously, in another preferred embodiment, the seat back made by assembling multiple components of similar or dissimilar materials for forming a plurality of hollow foam channels and integrated reinforcement structures on a reinforcement panel, see Figs. 4 and 5. Thus, having two or more wall portions that come together to make up the seat back. Examples of such multi-component assemblies are illustrated in U.S. Patent 6,739,673 incorporated by reference. That patent describes a reinforcement panel that may include a metal or plastic layer (e.g., a film, such as an adhesive backed film); it may be a natural material (e.g. leather or suede); it may be a woven or unwoven fabric (e.g., from a fibrous plastic or glass material); it may be a carpet; or it may be some other suitable structure for at least partially covering or encapsulating the seat back. The panel need not be capable of supporting its own weight, though in one embodiment it is. Preferably the reinforcement panel is suitable for containing or restraining any fractured seat back components in the event of seat back failure, or for otherwise locally imparting strength or toughness to the assembly. It can extend the full height or width of the seat back or both. It may also extend only a portion of the height, or a portion of the height and a portion of the width of the seat back. It may fold over from a front wall portion to a rear wall portion. The reinforcement panel may be secured to the seat back in any suitable manner, such as by adhesive, by insert molding, or otherwise. If the reinforcement panel is plastic, the panel may be thermoset or thermoplastic or a combination thereof. Examples of materials include, without limitation, high molecular weight polyolefin, polyester, polyethylene terephthalate, epoxy/polyester blend, vinyl, or the like. The panel may include an elastomeric component. The panel may comprise one or a plurality of continuous or discontinuous layers of material. It may be paintable. It may have a surface topography that is continuous or variable. The surface may have a texture that is formed or intrinsic in the material itself. Assembly methods of the various seat back components can include, and not limited to, adhesive bonding, vibration welding, insert molding, and mechanical fasteners or any combination thereof. These components can be formed via any, but not limited to, of the following processes: an injection molding process, compression molding, vacuum forming, stamping, extrusion, or pultrusion.

[0029] The foam 26 can be introduced as a separate pre-formed insert or foamed in place in one or more of the foam channels. Pre-formed foam inserts described above can be homogeneous in nature or contain additional reinforcement members located within the insert structure. Foam inserts may have a single consistent density, a density gradient, or two or more discrete densities (e.g. from the use of two or more adjoining foam pieces).

[0030] One possible approach incorporating foam into a foam channel is to include the step of bonding the foam to at least a portion of one of the wall portion. Thus, care is taken to help insure adhesion between the interface of the foam 26 and foam channel wall. To ensure adhesion, a number of methods or combination of methods can be utilized to accomplish this. By way of illustration, a surface treatment (e.g. a surface modifying treatment such as a flame or plasma spray treatment) or coating may be utilized on one or more areas of the interior foam channel wall, on a portion of a preformed foam insert or both. Another example is to form mechanical locking features into the foam channel wall, such as depression, projections, ribs, posts or the like. These features can be either formed during the creation of the foam channel wall or as a post forming operation by the addition of supplementary components. An adhesive may also be used to bond foam to the interior foam channel.

[0031] As illustrated in FIG. 1, assuming an x-y-z orthogonal coordinate system, the section and wall profiles vary generally in at least one axis, e.g., in the x direction, to define a hollow foam channel section for receiving of the foam filling. The section or wall profile might also vary in either or both of the y direction (i.e. cross car) or z direction (i.e. generally vertical in the seat's upright position) for an individual channel section. In general the individual foam channel sections are made up of components that are vertically oriented (i.e. in the z-direction), horizontally oriented (i.e. in the y-direction), of a predetermined geometry, or a combination of some or all of these. A grouping of a plurality of individual channel sections constitutes a "foam channel structure pattern." A seat back may include one or more patterns.

[0032] FIG. 3(A-F) illustrates examples of various alternative predetermined geometric configurations for foam channels or foam channel structure pattern on the seatback panel. Examples include, without limitation, the "C" shape, "U" shape, "X" shape, "A" shape, curves (e.g. sinusoidal curves), "+" shape, or the like. Pattern configurations are varied to optimize the load distribution characteristics of the seat back assembly depending on system requirements and vehicle packaging. For example, horizontally oriented foam channels may be employed at specific locations to control a bending or hinging point of the seat back during an impact event. In other examples, generally vertical foam channels may be employed to transfer loads from a top mounted seat belt or child seat anchor. The skilled artisan will appreciate that a combination of both horizontal and/or vertical foam channels and their location may be needed to enable the seat back assembly to perform its various requirements, (e.g., that which experienced by a top mounted center shoulder belt, top mounted child seat anchors, and luggage intrusion). Integrated reinforcement structures will be used in combination with the foam channels, at least in as much as they define the outer bounds of the foam channel itself.

[0033] The use of foam channels and integrated reinforcement structures are illustrated in the following discussion, by reference to two of the more commonly expected locations for foam channels and integrated reinforcement structures, specifically in the perimeter regions of a seat back and in the regions proximate hardware, such as seat belts, seat belt anchors, hinges, latching components or the like. [0034] For a number of applications, it is particularly attractive to incorporate a foam channel around at least a portion of the perimeter of the seat back to help increase horizontal stiffness, vertical stiffness, or both in the perimeter regions of the seat back. With illustrative reference to FIG.1, for most applications it is contemplated that an inboard edge of the foam channel is within 50 mm to 100 mm, preferably within 25 mm to 50 mm and even more preferably less than 25 mm of an edge defining the perimeter of the seat back. The inboard edge of the foam channel is the outboard edge of an integrated reinforcement structure. When an area is designated to be a foam channel, such channels should contain a foam filling along at least 25% of its length and across 25% of its width and 25% of its height, preferably at least 50% of its length and across 50% of its width and 50% of its height, and even more preferably at least 75% of its length and across 75% of its width and 75% of its height.

[0035] It is also preferable to form a foam channel in the area adjacent to any latch strikers or latch members, within 50mm to 100 mm of the latch, preferably within 25 to 50 mm of the latch, even more preferably within less than 25 mm of the latch. The effect of the reinforcement is to locally increase rigidity by at least 10% and aid in the distribution of various loads. In some applications, such as where the seat is intended to carry the load for a center belt, or a child seat tether, it may be desirable to modify, further reinforce or eliminate the top perimeter horizontally oriented foam channel to reduce the potential for hinge effect stress concentrator in that vicinity. In certain seat back configurations, it is beneficial to form a foam channel such that it at least partially overlaps the interface region of one or more of the latch strikers or latch members and the seat back. Preferably, an additional integrated reinforcement structure is formed within the interior of the foam channel, for accepting an attachment means for any latch strikers or latch members. See Section A-A of FIG. 1. In this illustration, a nut, bolt and washer means are being shown, but it should be noted that the attachment means can be, but not limited to: rivets, screws, nuts and bolts, push-pins, vibration welding, heat staking, or adhesive bonding.

[0036] In instances where a center passenger shoulder belt system is employed, or a top child seat tether is employed, optionally, design criteria is employed to help reduce the forward, downward and torsional or diagonal bending of the seat back that are caused by perimeter loads at or adjacent the shoulder belt or tether attachments. Preferably the foam channel or a foam channel and integrated reinforcement structure combination will provide good vertical stiffness (as this is the plane that is anticipated to endure the more severe bending forces), as well as good torsional stiffness (responsive to the diagonal offset loads a passenger imparts to a shoulder belt system). In such instances, it is preferable to alternate geometries of the foam channel either in a random or predetermined pattern, or to maintain the foam channel width up to about 40 mm, and more preferably up to about 30 mm (e.g., about 5 to about 30 mm). [0037] It will be appreciated that the above design criteria are preferred but are not intended as limiting. Depending upon the particular applications, variations to the above may be made. Moreover, it should be appreciated that forming a discrete foam channel need not occur in every application, and the need for and magnitude of such generally will be directly proportional relationship to the size of the seat back. Thus, for example, a smaller folding seat may not require a perimeter foam channel or it may only require foam channels in limited areas.

[0038] This invention contemplates the use of a lower transitional bracket or interfacing means to attach the seat back to a movable hinge or pivot assembly for connecting the seat back assembly to the body in white of a vehicle. This bracket can be separate part or integrated into the hinge assembly. The bracket is contemplated to be constructed of a high strength material such as steel, aluminum, or a reinforced plastic. The transitional bracket is designed to transfer the loads from the seat back, through the hinge assembly, and into the body in white. Preferably, each seat back will have at least one lower transition bracket located at the bottom of the seat back. The hinge assembly of the present invention is provided in any suitable manner for assuring that the seat back remains anchored to the vehicle body in white in the event of a sudden or rapid acceleration, deceleration, or a large force is applied. [0039] This invention contemplates the use of an upper transitional bracket or interfacing means to attach the seat back to a latching assembly for connecting the seat back assembly to the body in white of a vehicle, where such an upper attachment point is utilized. It should be understood that not all seat configurations include an upper attachment to the body in white. This bracket can be separate or integrated into the latching assembly. The bracket is contemplated to be constructed of a high strength material such as steel, aluminum, or a reinforced plastic. The transitional bracket is designed to transfer the loads from the seat back, through the latching assembly, and into the body in white. Preferably, each seat back will have at least one upper transition bracket located at or near the top of the seat back. The latch assembly (if applicable) of the present invention is provided in any suitable manner for assuring that the seat back remains anchored to the vehicle body in white in the event of a sudden or rapid acceleration, deceleration, or a large force is applied.

[0040] As will be appreciated, proper material selection will permit efficient design and molding of optimal wall thicknesses, part section thicknesses or both, in combination with proper selection of foam material and foam channel size and location for achieving the desired performance without substantially increasing vehicle weight, costs or intruding into interior space availability. [0041] By way of example, it is desired for many applications that the maximum foam density will range up to about 500kg/m³ or higher, more preferably it will range from about 15 to about 400kg/m³, and still more preferably, it will range from about 24 to about 128kg/m³. Foam compressive strength will range, per ASTM D1621 , from about 0.1 MPa to about 15 MPa, more preferably it will range from about 0.1 MPa to about 4 MPa.

[0042] By way of example, it is desired for many applications that the maximum wall stock thickness will range up to about 6 mm or higher, more preferably it will range from about 1.0 mm to about 4.0 mm, and still more preferably, it will range from about 0.5 mm to about 3.0 mm. Likewise, the maximum section thickness will range up to about 100 mm, more preferably it will range from about 20 mm to about 60 mm, and still more preferably it will range from about 15 to about 35 mm. With the utilization of foam channels, the wall thickness and section thickness is reduced in comparison to current seat back technology, allowing the seat back to meet the customer requirements while fitting in a smaller vehicle package or environment.

[0043] The materials selected for forming the walls of the seat backs of the present invention preferably exhibit an elastic modulus ranging from about 500 MPa to about 6000 MPa, and more preferably about 1300 to about 3000 MPa, and still more preferably about 1700 MPa to about 2500 MPa. In applications when the seat back is also to be used as a load bearing floor, it is preferable to select a material toward the higher end of the ranges.

[0044] The preferred flexural modulus of the seat back walls will be at least about 600 MPa, more preferably it will range from about 1300 to about 3500 MPa, and still more preferably about 1700 to about 2500 MPa.

[0045] The preferred yield strength of the seat back wall material ranges from about 10 to about 200 MPa. More preferably it will range from about 25 to about 70 MPa and still more preferably about 35 to about 55 MPa. Moreover, the ductility (as measured by percent elongation) of the material preferably ranges from about 20% to about 150%, and more preferably it is at least about 30% and still more preferably, it is at least about 100%.

[0046] The material also will preferably exhibit attractive processing characteristics, such as a melt flow rate (230C/3.8 kg-l; according to ASTM D1238) of about 0.300 to about 15.0 g/10 min to about 0.900 to about 3 g/10 min; a softening point (according to ASTM D 1525) of less than about 200C, and more preferably about 9OC to about 150C; linear-flow mold shrink (according to ASTM D 955) of about 0.001/mm/mm to about 0.02/mm/mm and more preferably about 0.003/mm/mm to about 0.09/mm/mm; or a combination of these properties.

[0047] Examples of preferred commercially available materials include Dow C702-20 Polypropylene and Magnum™ 1150EM₁ both available from The Dow Chemical Company and exemplar of the above mechanical properties.

[0048] Accordingly, in one preferred embodiment, the seat back substrate of the present invention preferably is made from a plastic material, and more preferably a thermoplastic material. In a particularly preferred embodiment, the seat back substrate is made from a high strength thermoplastic resin (either filled or unfilled) selected from styrenics, polyamides, polyolefins, polycarbonates, polyesters or mixtures thereof. Still more preferably they are selected from the group consisting of acrylonitrile butadiene styrene, styrene-acrylonitrile, polycarbonate/acrylonitrile/butadiene styrene, polycarbonate, polyphenylene oxide/polystyrene, polybutylene terephthalate, polybutylene terephthalate/polycarbonate, polyamide (e.g., nylon), polyesters, polypropylene, polyethylene, and mixtures thereof. "Filled" resins, well known within the industry, are materials in which a filler such as: glass, talc, clay, or similar materials are added to improve the inherent properties of the base resin.

[0049] Additionally, in another preferred embodiment, the seat back substrate of the present invention is made from a plastic material and processing method that is described in WO/2006/047366, herein incorporated by reference. Wherein the material described is premised upon the recognition for use as multiple layer elongated member of a propylene-based (e.g., a propylene-ethylene copolymer, a propylene-α-olefin copolymer, mixtures thereof or otherwise) copolymer that has a melting point that is below an adjoining polypropylene layer, and specifically an oriented polypropylene layer. Upon processing to form articles, the resulting materials (especially the oriented polypropylene layer) exhibits a degree of retained morphology from its initial drawn state heretofore not attainable using conventional materials. Accordingly, aspects of the material are premised upon the use of a propylene-ethylene copolymer that has an ethylene content of about 3 to about 25 wt.% (e.g., 5 to 15 wt.%), a melting range of about 50 to about 135°C, and a flexural modulus of about 8 to about 325 Mpa or higher (e.g., at least about 375 MPa), and a second thermoplastic material that includes a polyolefin, such as a propylene-based polymer. Such propylene-ethylene copolymer may have a Shore A Hardness of from about 40 to 90 (or higher), a molecular weight distribution of about 1.5 to about 4, and a melt flow rate of at least about 0.3 g/10 min, or any combination thereof.

[0050] The choice of foam material 26 to fill the foam channels may be classified as acoustical grade, structural grade, and energy absorbing grade or any combination thereof. This foam can be either open cell or close cell type foam. Examples of foams are found, without limitation, in U.S. Patents Nos. 6,949,588; 6,894,083; 6,803,390; 6,800,669; 6,699,916; 6,417,242; 6,355,341 and 6,213,540.

[0051] Accordingly, in one preferred embodiment, the foam channels in seat back of the present invention is preferably filled with a polyurethane foam material, and more preferably an expandable polyurethane foam material. In a particularly preferred embodiment, the foam channels are filled with expandable high-density polyurethane foam that has a density range up to about 500kg/m³ and present good adhesion properties to the seat back wall material. The foam is further characterized by having a compressive strength per ASTM D1621 of at least about 1000 KPa ranging up to about 7500 KPa, preferably ranging between about 4500 KPa and about 7000 KPa and even more preferably between about 6000 and about 7000 KPa.

[0052] Accordingly, in another preferred embodiment, the foam channels in seat back of the present invention are preferably filled with a polyurethane foam material, and more preferably an expandable polyurethane foam material. In a particularly preferred embodiment, the foam channels are filled with expandable low-density polyurethane foam that has a density range up to about 20kg/m³ and present good adhesion properties to the seat back wall material. The foam is further characterized by having a compressive strength per ASTM D1621 of at least about 80 KPa ranging up to about 150 KPa, preferably ranging between about 90 KPa and about 140 KPa and even more preferably between about 100 and about 130 KPa. The lower density foam would typically be utilized in seat backs that either have a lower set of load bearing requirements or in combination with a higher strength seat back wall material selection. [0053] Again, in another preferred embodiment, a combination of more than one foam material is deposed within the foam channels of the seat back. Some foam channels may utilize low-density foam, others may utilize higher density foam, while others my utilized a foam insert, or any combination of these. This is particularly beneficial to assist in the controlled distribution of various loads within and through the seat back, depending upon which loading condition or combination of loading conditions are being targeted in a particular seat back design. For example, but not limited to, distributing and dissipating seat belt loads, cargo intrusion loads or child seat latch loads.

[0054] An example of a possible foam channel configuration, see Fig.6, on a seat back is as follows: A foam channel, at least partially filled with a high-density foam 26 described above, extends from the area of the seat back hinge 28 to the area of latch or striker 30 located at or near the top of the seat back. The hinge interface footprint 32, the footprint comprising the area over which the hinge generally would overlie the seat back, with the seat back is disposed over the foam channel section such that the footprint extends laterally beyond the foam channel by at least about 10mm, see Fig.8 The latch or striker interface footprint 34, the footprint comprising the area over which the latch or striker generally would overlie the seat back with the seat back, also is disposed over the foam channel section such that the footprint extends laterally beyond the foam channel by at least about 10mm, see Fig.7. This configuration shows a possible way to enable the loads the seat back is subject to, to be distributed, transferred and dissipated between the hinge and latch or striker. [0055] Another example of a possible foam channel configuration, see Fig.1, on a seat back is as follows: A foam channel, at least partially filled with a high-density foam 26 described above, extends from the area of the seat back hinge 28 to the area of latch or striker 30 located at or near the top of the seat back. The hinge interface footprint with the seat back is disposed over the foam channel section such that the footprint extends laterally beyond the foam channel by at least 10mm, see Fig.1A. An integrated reinforcement structure is generally deposed within the center of the foam channel, in the y direction, adapted to receive a mechanical fastening method to attach the hinge to the seat back. The latch or striker interface footprint with the seat back also is disposed over the foam channel section such that the footprint extends laterally beyond the foam channel by at least about 10mm. This configuration shows another possible way to enable the loads the seat back is subject to, to be distributed, transferred and dissipated between the hinge and latch or striker. It is important to note that the interface footprints can either go beyond the foam channel section or be contained completely within the section, or any combination thereof.

[0056] The skilled artisan will recognize that the above teachings may be modified in any of a number of ways yet still stay within the scope of the present invention. Among the many different options are the following. [0057] While the technology of the present invention has been illustrated utilizing a blow molding fabrication process for the plastic substrate of the seat back, it is not intended to be limited only to substrates manufactured in this fashion. So long as the seat back contains areas to have foam channels, then the taught invention can be utilized with seat back substrates manufactured with other fabrication techniques, including but not limited to injection molding, lost core processing, rotoforming, compression molding (with or without decorative or structural inserts), thermoforming, or the like.

[0058] As will be appreciated from the above, preferred seating systems that are optimized in accordance with the criteria outlined herein, and using the referenced materials, consistently should pass United States and European government test standards for motor vehicles (e.g., as addressed in FMVSS 207, FMVSS 210, FMVSS 225 (49 CFR 571.207, .210, .225) or ECE 17; all such standards being expressly incorporated by reference herein) as well as the requirements of automobile original equipment manufacturers and their suppliers.

[0059] The present invention contemplates techniques and methods for the optimization of one or more of substrate material selection, foam filler material selection, wall thickness, section thickness, hinge design, and latch design, for realizing the desired stiffness and strength to meet traditionally demanding load requirements in automotive vehicles occasioned of center mounted shoulder belt loads, child seat anchor loads, or cargo intrusion. The skilled artisan will recognize, however, that from application to application, design requirements will vary, and therefore a reasonable amount of experimentation may be needed to adapt the various teachings to the unique intended environment. By way of example, part size, seat belt location, hinge points, latch locations, and split ratio may affect final design. It is believed that the use of conventional computer aided engineering (CAE) techniques in combination with the present teachings will yield satisfactory results, which can be improved as desired with conventional techniques for localized steel reinforcement (e.g., in high stress areas, such as hinge points, latch areas, seat belt mounting areas, and armrest support areas).

Claims

008/058557

What is claimed is:

1. A seating assembly for an automotive vehicle, comprising: a. a blow molded plastic seat back- having a forward wall portion and a rearward wall portion, and a plurality of foam channels with a foam disposed therein, and a plurality of integrated reinforcement structures for defining an integrated reinforcement structure pattern; b. a hinge assembly having a bracket portion including a first side wall portion, an opposing second side wall portion, the walls adjoined to the seat back and a pivot member for hingedly anchoring the seat back directly to a first body in white portion of the automotive vehicle; and c. a latch secured to a second body in white portion of an automotive vehicle; .and a striker having a projecting striker bar attached to a mounting portion in overlapping engagement with the rearward wall portion of the seat back for intetferingly engaging the latch to maintain the seat back in a generally upright position. .

2. The seating assembly qf daim 1 , wherein the bracket is deposed over a foam channel in the seat back.

3. The seating assembly of any of. claims 1 or 2, wherein an intermediate wall portion of the bracket connects the first wall section to the second wall section, includes a section terminating at an edge that extends beyond a first distal .end of the first sjde wall portion and toward a second distal -end of fie second side wall portion. 4. The seating assembly of any of claims 1 through 3, wherein the mounting portion of the striker includes at least one flange for overlapping and engaging $he blow molded plastic seat back. 5. The seating assembly of any of claims 1 through 4, wherein the striker is disposed long a top edge portion of the blow molded seat back, β. The seating assembly of any of claims 1 through 4, wherein the striker is disposed along a side edge portion of the blow molded seat back. 7. The seating assembly of any of claims 1 through 4, wherein the striker is disposed in an upper corner of the blow molded seat back.

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RECTIFIED SHEET (RULE91) A

8. The seating assembly of any of claims 1 through 7, wherein the seat back is fabricated in a single blow molding operation.

9. The. seating assembly of any of claims 1 through 8, wherein the first and second wail portions of the seat back are fabricated separately and joined thereafter;

10. The seating assembly of any of claims 2 through 9, wherein the foam is introduced to the foam channels after the formation of the foam channels.

11. The seating assembly of any of claims 2 through 10, wherein at least a portion of the foam is introduced to the foam channels prior to joining the first and second wall portions

12. A seating assembly for an automotive vehicle, comprising: a, a seat back formed from a molded polypropylene plastic having a forward wall portion and a rearward wall portion, a plurality of polyurethane foam channels; and h. an attachment assembly having a bracket portion including a first side wall portion, an opposing second side wail portion, the walls adjoined to the seat back, anchoring the seat back to a first body in white portion of the automotive vehicle; wherein the seating assembly is capable of exhibiting at least one response selected from (1) withstanding wihout rupture at least about 11000 Newtons in the direction in which the seat faces in a plane, parallel to the longitudinal centeriine of the vehicle; (2) upon rapid acceleration up to at least about 20 g, substantially no fragmentation of the seat back WAh at least a 20 kg mass placed behind the seat back; or (3) a combination of both responses (1) and (2).

13. A Voidable automotive vehicle seating system, comprising: a. a molded thermoplastic seat back including a first wall portion and an opposing second wall portϊon and one or more foam channels disposed . therebetween; b. a hinge assembly for pivbtally anchoring the seat back to an automotive vehicle, including a receiving portion for securing the seat back to the hinge assembly, and a mounting portion for securing the hinge assembly to the vehicle; and . c. a self locking releasable retention mechanism for maintaining the seat back in a generally upright position, wherein the seating system is capable of withstanding without rupture at least about 13000 Newtons in a direction in which

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RECTIFIED SHEET (RULE91) ISA/EP the seat faces in a plane, parallel to the longitudinal cεnterliπe of She vehicle, and exhibits, upon rapid acceleration up to about 20 to about 30 g,,no fragmentation of the seat back with at least a 20 kg mass placed behind the seat back.

14. The system of claim 13, wherein the thermoplastic includes a polycarbonate material, a styrenic material, or a mixture thereof.

15. Tho system of any of claims 13 or 14, wherein the thermoplastic includes a polyester.

16. Ttie system of any of claims 13 through 15, wherein the thermoplastic includes a polyamide.

17. The system of any of claims 13 through 16, wherein lhe thermoplastic includes a polyolefin.

18. The system according to any of claims 13 through 17, further comprising a reinforcement inserted in a space between the first wall portion and the second wall portion.

19. The system according to any of claims 13 through 18, wherein at least one of the foam channel walls is a single rib member that extends between the first wall portion and the second wall portion.

20. ^■ The system of any of claims 13 through 19, wherein the seat back is fabricated in a single blow molding operation.

21 Th© system of any of claims 13 through 20, wherein ths first and second wall portions of the seat back are fabricated separately and joined thereafter..

22. The- system of any of claims 13 through 21, further comprising a shoulder belt mounted to the seat back.

23. The system of any of claims 13 through 22, wherein the retention mechanism is located along a side of the seat back, the top of the seat back or a combination thereof.

24. The system of any of claims 13 through 23, wherein the foam is introduced to foam channels after the formation of the foam channels.

25. The system of any of claims 13 through 24, wherein at least a portion of the foam is introduced to the foam channels prior to joining the first and second wall portions.

26. A seating assembly for an automotive vehicle, comprising: a, " a forward wall portion;

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RECTIFIED SHEET (RULE91) ISA/EP b. a rearward wall portion created separately from the first portion, wherein the forward wall portion and rearward wall portion comprise dissimilar materials; c. at least one interface between the forward wait portion and rearward wall portion wherein the first wall and second wall are joined; further wherein the first portion and the second portion are defined to include a plurality of individual integrated reinforcement structures; and further wherein the first portion and Jhe second portion includes one or more foam channels with a foam disposed therein; d. a hinge assembly having a bracket portion including a first side wall portion, an opposing second side wall portion, Jhe walls adjoined to the seat back and a pivot member for hingedly anchoring the seat back directly to a first body in white portion of the automotive; s. a latch secured to a second body in white portion of an automotive vehicle; and a striker having a projecting striker bar attached to a mounting portion in overlapping engagement with the rearward wall portion of the seat back for interferjngly engaging the latch to maintain the seat back in a generally upright position.

27. The assembly of cfaim 26, wherein at least a portion of the foam is introduced to the foam channels prior to Joining the first and second wall portions.

28. The assembly of any of claims 26 or 27, wherein the seating assembly is capable of exhibiting at least on© response selected from (1) withstanding without rupture at least about 13000 Newtons in the direction in which the seat faces in a plane, parallel to the longitudinal centerline of jthe vehicle; (2) upon rapid acceleration up to at least about 20 to about 30 g, substantially no fragmentation of the seat back with at feast a 20 kg mass placed behind the seat back; or (3) a combination of both responses (1) and (2).

29. A method of manufacturing a (seating assembly for an automotive vehicle comprising the steps of: a. forming a forward wall portion; b. forming a rearward wall portion; c. joining the forward and rearward wall portions; d. introducing a foam into a plurality of foam channels deposed between the first and second wall portions;

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RECTIFIED SHEET (RULE91) ISA/EP β. joining a hinge means to the front wall portion, wherein the hinge means at least partially overlaps at least one of the foam channels; and f. joining a latching means to the rear wall portion, wherein ihβ latching means at least partially overlaps at least one of the foam channels.

30. A method of manufacturing a seating assembly for an automotive vehicle comprising the steps of: a. integrally forming a forward wall portion and rearward wall portion, wherein there is a plurality of open channels deposed between the first and second wall portions; b. introducing a foam into at least one of the plurality open channels deposed between the first and second wall portions; c. joining a hinge means to at least one of the wall portions, wherein the hinge means at least partially overlaps at least one of the channels, further wherein foam has been introduced; and

^' d. ^• Joining s> latching means to at least one of the wall portions, wherein the latching means at least partially overlaps at least one of the channels, wherein foam has been introduced.

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RECTIFIED SHEET (RULE91) ISA/EP