Patent Publication Number: US-2022227273-A1

Title: Vehicle seat panel with discontinuous foam layer

Description:
TECHNICAL FIELD 
     Noon The present disclosure relates to vehicle seats and, more specifically, to decorative trim of vehicle seats. 
     BACKGROUND 
     An advancement known as Cover Carving Technology (CCT) has recently been brought to the vehicle seating market. CCT offers the ability to form very sharp feature lines in the decorative surface of upholstery materials such as leather or textiles that were previously considered non-formable with conventional polymer forming methods such as molding or thermoforming. Unlike synthetic polymer-based films, such upholstery materials cannot be simply heated and pressed against a molding tool and expected to take the shape of the mold surface when subsequently cooled. 
     An example of a technique with one or more elements in common with CCT is disclosed in U.S. Pat. No. 10,710,481 by Etienne, et al. The Etienne patent discloses a method in which a foamable material is applied to a carrier and subsequently pressed against a covering material in a mold. The foamable material expands and hardens in the mold with the outer surface of the covering material taking the shape of the mold surface. Limitations of the technology include size limitations and limitations on placement of the foam layer. For example, the total width of the foam layer is limited to the width of the mold, and the process sometimes results in the placement of foam material in locations where it is unnecessary. 
     SUMMARY 
     In accordance with one or more embodiments, a method of making a vehicle seat includes the step of molding a discontinuous layer of foam on a non-decorative side of a decorative layer of material to form a seat panel that is subsequently attached to a vehicle seat structure to form at least a portion of an exterior surface of the vehicle seat. 
     In one or more embodiments, the discontinuous layer of foam is molded in a single molding operation. 
     In one or more embodiments, the method includes forming a loop in the decorative layer of material between separate first and second areas of the decorative layer of material before the step of molding. 
     In one or more embodiments, the decorative layer of material is arranged so that a portion of the non-decorative side of the decorative layer of material is facing itself during the step of molding. 
     In one or more embodiments, a portion of the decorative layer of material located between separate first and second areas of the decorative layer of material is excluded from a foam molding cavity during the step of molding. 
     In one or more embodiments, a portion of the decorative layer of material is disposed in a foam molding cavity of a molding tool during the step of molding and another portion of the decorative layer of material is disposed in a secondary cavity of the molding tool during the step of molding. 
     In one or more embodiments, the discontinuous layer includes a first portion molded on a first area of the decorative layer of material and a separate second portion molded on a second area of the decorative layer of material. The method also includes forming permanent concave features in a decorative side of the decorative layer of material at said first and second areas. 
     In one or more embodiments, the discontinuous layer of foam is formed by transferring a continuous layer of foamable material from a transfer film to the non-decorative side of the decorative layer of material. 
     In one or more embodiments, the method includes disposing the decorative layer of material between opposing first and second portions of an open molding tool and closing the molding tool to form a foam molding cavity with a portion of the decorative layer of material in the foam molding cavity. A central portion of the decorative layer of material is outside the foam molding cavity after the step of closing and during the step of molding. 
     In one or more embodiments, a first portion of a foam molding tool includes first and second sections configured to move toward and away from each other. The method also includes disposing a central portion of the decorative layer of material between the first and second sections of the first portion of the molding tool before a step of closing the molding tool. 
     In one or more embodiments, the decorative layer of material is in sheet form and placed in tension during a step of disposing the decorative layer of material between opposing first and second portions of an open molding tool with forces applied to opposite edges of the decorative layer of material in opposite directions and another force applied to a central portion of the decorative layer of material in a direction transverse to said opposite directions. 
     In one or more embodiments, separate first and second portions of the discontinuous layer of foam are on opposite left and right sides of a seat back of the vehicle seat when the seat panel is attached to the vehicle seat structure. 
     In one or more embodiments, wherein separate first and second portions of the discontinuous layer of foam are on opposite left and right sides of a seat bottom of the vehicle seat when the seat panel is attached to the vehicle seat structure. 
     In one or more embodiments, the seat panel is folded to form a pocket between separate first and second portions of the discontinuous layer of foam when the seat panel is attached to the vehicle seat structure so that a portion of a decorative side of the decorative layer of material faces itself within the pocket. 
     In one or more embodiments, separate first and second portions of the discontinuous layer of foam have a first orientation relative to each other during the step of molding and a different second orientation relative to each other after attachment to the vehicle seat structure. 
     Various aspects, embodiments, examples, features and alternatives set forth in the preceding paragraphs, in the claims, and/or in the following description and drawings may be taken independently or in any combination thereof. For example, features disclosed in connection with one embodiment are applicable to all embodiments in the absence of incompatibility of features. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements, and wherein: 
         FIG. 1  is a cross-sectional side view of part of a method of making a seat panel from a decorative layer of material in a foam molding tool; 
         FIG. 2  illustrates a looped portion of the decorative layer of  FIG. 1  in a secondary cavity of the molding tool; 
         FIG. 3  illustrates a layer of foam supported between the decorative layer and a portion of the molding tool; 
         FIG. 4  illustrates first and second portions of the molding tool brought together to form a foam molding cavity with a portion of the decorative layer in the molding cavity; 
         FIG. 5  illustrates expansion of the layer of foam in the molding cavity; 
         FIG. 6  illustrates separation of the first and second portions of the molding tool; 
         FIG. 7  illustrates removal of the molded part from the molding tool; 
         FIG. 8  is a cross-sectional view of the molded part; 
         FIG. 9  is a cross-sectional view of the seat panel after trimming away edges of the molded part of  FIG. 8 ; 
         FIG. 10  is a top view of a vehicle seat showing an exemplary location of the seat panel along a rear face of the vehicle seat; 
         FIG. 11  is a perspective view of a molded seat panel illustrated in partial cross-section as part of a seat back; 
         FIG. 12  is a perspective view of a molded seat panel illustrated in partial cross-section and forming a map pocket along a seat back; and 
         FIG. 13  is a perspective view of a molded seat panel illustrated in partial cross-section as part of a seat bottom. 
     
    
    
     DETAILED DESCRIPTION 
     Described below is a vehicle seat and a method of making the vehicle seat including molding a layer of foam on a decorative layer of material to form a seat panel of the seat. The method compliments the above-described CCT by enabling formation of a foam layer that is wider than the foam molding tool and by enabling the placement of localized portions of the foam layer at only the desired areas of the seat panel. 
       FIGS. 1-9  illustrate an exemplary method of making a vehicle seat that includes forming a seat panel in a foam molding tool  10 . The foam molding tool  10  includes a first portion  12  and a second portion  14  and is shown in an open condition in  FIG. 1 , ready to receive materials for molding. The first and second portions  12 ,  14  of the tool  10  are moveable toward and away from each other. In this instance, the first portion  12  of the tool  10  is a bottom portion and a cavity side of the tool, the second portion  14  is a top portion and a core side of the tool, and the tool portions  12 ,  14  are moveable toward and away from each other in the vertical direction. 
     The first portion  12  of the molding tool  10  includes first and second sections  16 ,  18  that are moveable toward and away from each other along a direction transverse to the direction of relative movement of the first and second tool portions  12 ,  14 . When moved away from each other as in  FIG. 1 , an opening  20  is formed between the two sections  16 ,  18 . A decorative layer of material  22  in sheet form is supported between the tool portions  12 ,  14  with a decorative side  24  of the material facing a mold surface  26  of the first portion  12  and an opposite non-decorative side  28  facing a mold surface  30  of the second portion  14 . 
     The decorative layer of material  22  is a fabric such as leather, a natural and/or synthetic textile, or a polymer-based material (e.g., simulated leather). The fabric is provided with a uniform thickness (e.g., 0.1 mm to 2.0 mm) that is orders of magnitude less than its planar dimensions (e.g., 25 mm to 1 meter) and is characterized by an inability to support its own weight without folding or buckling when the planar dimensions are horizontal as in  FIG. 1  and when held by only one edge. The decorative side  24  is intended to form at least a portion of the visible exterior surface of the vehicle seat once attached to an underlying vehicle seat structure. The decorative layer of material  22  may itself be a multilayer material with a different non-decorative backing layer forming the non-decorative side  28 , for example. 
     When first placed between the portions  12 ,  14  of the open molding tool  10 , the decorative layer  22  is supported at least along opposite edges at its perimeter. For example, each opposite edge may be grasped by a clamp  32  and biased away from each other by springs, actuators, or other suitable means so that the decorative layer is taut when oriented horizontally as shown. Such biasing clamps  32  may be referred to as tensioners. 
     Another tensioner  34  is located on the non-decorative side  28  of the decorative layer  22 —i.e., above the decorative layer of material in  FIG. 1 . The tensioner  34  is moveable with respect to the first tool portion  12  and the decorative layer  22 . With the first and second sections  16 ,  18  of the first tool portion  12  moved away from each other, the tensioner  34  is brought into contact with the decorative layer  22  and, in particular, into contact with the non-decorative side  28  of a central portion  36  of the decorative layer. The central tensioner  34  continues moving toward the first tool portion  12 , bringing the decorative side  24  of the decorative layer  22  into contact with the tool portion  12  at the perimeter of the mold surface  26 , and bringing the central portion  36  of the decorative layer through the opening  20  between the sections  16 ,  18  of the first tool portion  12 . 
     The clamps or other tensioners  32  move toward each other and toward the center of the tool  10  in response, permitting more of the decorative layer  22  to be brought within the projected area of the molding tool while maintaining tension in the layer of material  22 . In this manner, even non-stretchable fabrics can be used as the decorative layer  22 . As shown in  FIG. 2 , a loop  38  is formed in the decorative layer  22  as it passes through the opening  20  such that a portion of the non-decorative side  28  of the layer  22  is facing itself on the inside of the loop. When the desired amount of the decorative layer  22  has passed through the opening  20 , the tensioner  34  stops moving and the sections  16 ,  18  of the tool portion  12  are moved toward each other such that the decorative layer  22  is clamped therebetween with the loop  38  housed in a secondary cavity  40  of the tool. The secondary cavity  40  may be referred to as a safe chamber—i.e., a chamber in which subsequently introduced foam material will not be able to reach the portion  36  of the decorative layer  22  housed there. 
     As illustrated in  FIG. 3 , a layer of foamable material  42 ′ is then presented facing the non-decorative side  28  of the decorative layer  22 . The layer of foamable material  42 ′ may be an uncured and/or viscous layer of a foam precursor material which has not yet begun to expand into a foam or has not yet fully expanded—e.g., a diisocyante/polyol mixture in the case of polyurethane foam. In this case, the layer of foamable material  42 ′ is provided on a carrier or transfer film  44 . In one embodiment, the layer of foamable material  42 ′ is sprayed or otherwise deposited on the transfer film  44  in a parallel process while the decorative material  22  is being presented to and arranged in the molding tool  10  as in  FIGS. 1 and 2 . The layer of foamable material  42 ′ may for example be sprayed onto an upward-facing surface of the transfer film  44  and then inverted when introduced over the decorative layer  22  in the molding tool  10 . In other embodiments, the layer of foamable material  42 ′ may be deposited directly onto the exposed portions of the decorative layer  22  while in the tool  10 , or the layer of foamable material can be poured or injected into a mold cavity formed when the tool  10  is in a closed condition. The layer of foamable material  42 ′ is continuous in this example and has a width (w) approximately the same as that of the molding tool  10 . 
     The first and second portions  12 ,  14  of the molding tool  10  are next moved toward each other to the closed condition as shown in  FIG. 4 , thereby forming a foam molding cavity  46  between the tool portions  12 ,  14  defined by the first and second mold surfaces  26 ,  30 . One portion of the decorative layer  22  is thereby positioned in the foam molding cavity  46  while another portion  36  of the decorative layer  22  is excluded from the foam molding cavity. The portion of the decorative layer  22  in the foam molding cavity  46  includes first and second areas  48 ,  50  respectively located at the first and second sections  16 ,  18  of the first portion  12  of the tool  10 . The carrier film  44  is omitted in  FIGS. 4-6  for clarity. 
     The first and second areas  48 ,  50  of the decorative layer  22  are on opposite sides of the central portion  36  of the layer  22 , which is the portion of the decorative layer excluded from the foam molding cavity  46  when the molding tool  10  is closed. Although the illustrated central portion  36  is at the geometric center of the decorative layer  22  in the illustrated example, this is not required. The central portion  36  is merely located between the first and second areas  48 ,  50  of the decorative layer  22  and is not intended to have any foam material molded thereon. In some cases, the decorative layer  22  may include a plurality (n) of distinct areas to receive a portion of foam with a corresponding plurality (n-1) of central portions between those areas. 
     With the tool  10  in the closed condition of  FIG. 4 , each of the first and second areas  48 ,  50  of the decorative layer  22 , the layer of foamable material  42 ′, and the optional transfer film  44  is arranged in the foam molding cavity  46 . The decorative side  24  of the decorative layer  22  faces one mold surface  26 , the layer of foamable material  42 ′ is in contact with the non-decorative side  28  of the decorative layer, and the transfer film separates the layer of foamable material from the other mold surface  30 . To arrive at this stage of the process, the edge tensioners  32  may be configured to permit more of the decorative layer  22  to be pulled within the perimeter of the tool as the cavity  12  and core  14  are brought together. 
     With the molding tool  10  in the closed condition, the layer of foamable material  42 ′ expands such that the foam molding cavity  46  is entirely filled with the multiple layers of materials. The foamable material  42 ′ cures or hardens to form a layer of foam  42  sandwiched between the decorative layer of material  22  and the mold surface  30  as shown in  FIG. 5 . While some of the foamable material may be permitted to leak from the cavity  46  at the parting line of the tool  10 , the pressure from the foam expansion forces the fabric of the decorative layer  22  to conform to the shape of the mold surface  26 . When the foamable material cures or hardens, that shape is permanently locked into the decorative side  24  of the decorative layer  22 . The material of the foam layer may be formulated to be relatively rigid compared to the types of foam materials typically used as thick cushioning layers of vehicle seats so that the sharpness of the feature lines  52  is maintained after the molded part is removed from the tool. In this manner, very sharp feature lines  52  can be formed into the decorative surface of any type of fabric or upholstery, including non-stretchable materials such as leather or tightly woven textiles. And there is no need to heat the decorative layer of material  22  prior to forming as is typically required when thermoforming polymer-based materials. 
     Once the layer of foam  42  is formed, tension is released from the decorative layer  22  and the tool portions  12 ,  14  are separated as in  FIG. 6 . The transfer film  44 , if used, may be removed once the tool  10  is in the open condition. 
     The first and second sections  16 ,  18  of the first portion  12  of the tool  10  are then separated, as in  FIG. 7 . The layer of foam  42  is thereby made discontinuous with distinct and separate portions. A first portion  54  of the discontinuous layer of foam  42  is on the first area  48  of the decorative layer  22 , and a separate second portion  56  of the discontinuous layer of foam is on the second area  50  of the decorative layer. The central tensioner  34  is then moved away from the decorative layer  22  and out of the previously formed loop  38  of material so that the molded part can be removed from the molding tool  10 . 
     The loop  38  can then be removed by moving the first and second areas  48 ,  50  of the layer away from each other, as in  FIG. 8 . The edges of the molded part can then be trimmed away, as shown in  FIG. 9 . The resulting seat panel  58  includes two relatively rigid areas  48 ,  50  of foam-backed fabric with separate portions  54 ,  56  of the discontinuous layer of foam  42  molded onto them and separated by a central portion  36  onto which none of the layer of foam  42  is molded—i.e., the central portion is where the layer of foam  42  is discontinued. The central portion  36  thus retains its flexible and foldable fabric characteristics. 
       FIG. 10  is a top view of a vehicle seat  60  shown in partial cross-section through a seat back  62  of the seat to illustrate a possible application of the finished seat panel  58 . Here, the seat back  62  extends upward from a seat bottom  64 , and the seat panel  58  is affixed over an underlying seat structure (e.g., a metal frame or composite load-supporting structure) and/or a layer of cushioning foam to define a portion of the exterior surface of the seat  60 . Part of the decorative side  24  of the decorative layer  22  faces away from the seat  60  in a rearward direction with respect to a seat occupant, and other parts of the decorative side of the decorative layer face away from the seat in opposite transverse directions (i.e., left and right) with respect to the seat occupant. The seat panel  58  spans the width of the rear of the seat back  62  and wraps around to the left and right sides of the seat back. 
     The seat panel  58  can be affixed to the underlying seat structure by any conventional means. For example, the panel  58  may be sewn together with other panels to form a decorative covering for the seat that is slipped over the seat structure at final seat assembly. Or the panel can be affixed to a utility seat covering already on the seat structure via sewing, hook and loop fasteners, adhesive, etc. 
     Notably, the first and second areas  48 ,  50  of the decorative layer  22  can be oriented differently when attached to the seat structure than they were during the molding process due to the retention of the fabric-like character of the central portion  36  of the decorative layer. With reference to  FIG. 8 , reference plane A, which is parallel with the flattened central portion  36 , forms an angle α with a tangent of reference surface B, as molded. When affixed to the seat structure as in  FIG. 10 , the angle α is different—approximately doubled from the as-molded angle in this particular example. This is advantageous because the layer of foam  42  could not be molded onto the decorative layer  22  in the orientation illustrated in  FIG. 10 , for example, without creating a die-lock condition or without the use of complex lifters or slides in the molding tool. 
     As such, making the layer of foam  42  discontinuous not only prevents the waste of foam material where it is not desired, it also permits the seat panel  58  to be reshaped during assembly without additional material shaping processes. In other words, omission of the relatively rigid foam on a portion of the decorative layer of material provides advantages over a continuous layer of foam, such as the ability to wrap a foam-backed fabric around bends or fold the seat panel for packaging, shipping, or into a folded configuration when applied to the seat structure. In some cases, the unprocessed portion of the decorative layer of material is stretched across a seat frame and/or backed with hard or soft materials when attached to the seat to give the seat panel  58  its final structure. 
     Additionally, as illustrated in  FIG. 8 , the width (W) of the discontinuous layer of foam  42  and of the finished seat panel  58  can be wider than the width (w) of the molding tool  10  and of the foam molding cavity  46 . This enables the use of smaller molding presses and molding tools, each of which reduces costs and required space in a manufacturing facility. The discontinuous layer of foam  42  can also be molded in a single molding operation, meaning that the separate first and second portions  54 ,  56  of the foam layer are molded in the same molding tool at the same time with a single introduction of foamable material to the foam molding cavity. 
       FIGS. 11-13  illustrate seat panels  58  made using embodiments of the above-described method. Each of the illustrated seat panels  58  forms a different portion of the exterior of the vehicle seat of which it is a part. Forward (Fw), rearward (Rw), left (L), and right (R) directions are labeled in the figures with respect to a seat occupant.  FIG. 11  is a perspective view of the seat panel  58  as viewed from a forward-facing side of a seat back  62 . An outline of the seat back  62  is shown in phantom where the top of the seat back is cut-away, and an underlying seat structure (e.g., frame and cushion) is omitted to clearly show the non-decorative side of the panel  58 . The illustrated seat panel  58  is arranged along a rear-facing side of the seat back  62 , similar to that of  FIG. 10 , with the first and second portions  54 ,  56  of the discontinuous layer of foam  42  extending from the central portion  36  of the decorative layer  22  and wrapping around to the opposite left and right sides of the seat back. From the perspective of  FIG. 11  a sharp feature line  52  is visible in the decorative layer  22  backed by one of the portions  56  of the foam layer  42 . 
       FIG. 12  is a perspective view of the seat panel  58  as viewed from a rear-facing side of a seat back. An outline of the seat panel  58  is shown in phantom where it is cut-away, and the underlying seat structure (e.g., frame and cushion) is omitted. In this example, the seat panel  58  is folded to form a pocket  66  between the separate portions  54 ,  56  of the discontinuous layer of foam when the seat panel is attached to the vehicle seat structure. A portion of a decorative side  24  of the decorative layer of material faces itself within the pocket  66  with one portion  54  of the layer of foam arranged above the pocket, the central portion  36  of the decorative layer forming the pocket, and the other portion  56  of the layer of foam overlying the pocket. The illustrated configuration can be attached to the underlying seat structure along the rear-facing side of the seat back  62  as a map pocket, for example. 
       FIG. 13  is a perspective view of the seat panel  58  as viewed from a top-rear side of a seat bottom  64 . An outline of the seat bottom  64  is shown in phantom where it is cut-away, and the underlying seat structure (e.g., frame and cushion) is omitted. In this example, the seat panel  58  is arranged along an upward facing side of the seat bottom  64  with the first and second portions  54 ,  56  of the discontinuous layer of foam  42  extending from the central portion  36  of the decorative layer and wrapping over bolster portions of the seat bottom to form the opposite left and right decorative surfaces of the seat bottom. From the perspective of  FIG. 13 , sharp feature lines  52  are visible in the decorative layer backed by the portions  56 ,  58  of the foam layer  42 . These are of course only examples of locations along the exterior of a vehicle seat at which the seat panel  58  can be affixed. 
     It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims. 
     As used in this specification and claims, the terms “for example,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.