Abstract:
A vehicle seat assembly having a suspension panel for the seat pad that is formed of resin impregnated compressed fibrous bat. The suspension panel is formed with corrugations and other contours to enable the suspension panel to flex in a predetermined manner to provide suspension to a seat pad. The suspension panel, when used in the seat back can also form the rear trim panel of the seat back thus reducing the number of components in the seat back as the suspension panel serves multiple functions. The fibrous panel can be reclaimed after the useful life of the seat and manufactured into a new panel thereby reducing the quantity of seat components that are scrapped after use. In addition, recycled fibers can be used originally thereby increasing the amount of recycled content in the seat assembly.

Description:
This is a division of U.S. patent application Ser. No. 09/076,544, filed May 12, 1998 now U.S. Pat. No. 6,213,557 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to a vehicle seat assembly and in particular to one having a thermoformed suspension panel made of a resin or thermoplastic impregnated compressed fibrous bat to provide suspension for the seat pad and in some cases, an external shell or rear trim cover for the seat back. 
     Efforts are being made in the automotive industry to reduce the negative environmental impact of motor vehicles. One way doing this is to increase the amount of recycled materials that go into a new automobile. Another way is to recycle components from a motor vehicle at the end of a vehicle&#39;s useful life. A third way of reducing the negative environmental impact of a vehicle is to reduce the number of individual components in a vehicle by designing components that perform multiple functions instead of just one function. This can reduce the quantity of raw material used in a vehicle as well as reduce the time and energy required to produce the vehicle. 
     By recycling the seat components, several different processes are contemplated. The most preferred process is to reuse a seat component without any alteration from its original form. The next level is to reclaim a component and manufacture it into another useful component. This has been done regularly with most metals in which the reclaimed parts are melted down and remade into a new component. The next level is to shred the components, such as the foam pad, into small pieces that can be used in another product such as rebonded carpet padding. This is less desirable in that the carpet padding, after its useful life, is not reused and is land filled. Fourth, and least preferred, is shredding of the seat components followed by land filling of the shredded materials. 
     The seat assembly of the present invention facilitates the recycling of the vehicle seat assembly by providing a suspension panel for supporting the seat pad that can be made of a recycled material and which can be reclaimed and manufactured into a new component after the useful life of the seat assembly. When the suspension panel is also used as the rear trim cover of a seat back, multi-tasking is involved, using a single component for both the suspension as well as the rear trim panel. This serves to reduce the number of components in a seat assembly. 
     The suspension panel of the present invention is manufactured of a resin or thermoplastic impregnated compressed fibrous bat material. Plastic fibers are preferred, such polyethelyne terephthalate (PET) from recycled beverage containers, virgin PET fibers or post industrial polypropylene. Alternatively, offal from various manufacturing processes can be used, such as offal from vehicle head liner manufacturing. Other fibers can be used as well. Plastic fibers are preferred over natural fibers such as cotton or wood pulp due to their resistance to absorption of water. However, cotton fibers and other natural fibers can be used in the suspension panel. 
     The panels are formed with corrugations and other contours that provide for differing degrees of flexibility in the panel at different locations. With each particular seat design, the suspension panel can be individually designed to provide specific deflection characteristics. The deflection characteristics will be designed in conjunction with the seat pad to provide a desired comfort. 
     The suspension panel can be thermoformed and bonded to a covering fabric during the thermoforming process to provide a decorative exterior surface to the suspension panel. This is particularly useful when the panel also serves as a seat shell forming exterior surface of the seat back. A fabric surface matching that of the seat trim cover overlying the seat pad can be bonded directly to the suspension panel. 
     Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a rear perspective view of the vehicle seat of the present invention having a formed suspension panel and rear trim panel; 
     FIG. 2 is an exploded, perspective view of the seat assembly of the present invention; 
     FIG. 3 is a perspective view of an alternative embodiment of the formed suspension panel; and 
     FIG. 4 is a perspective view of an another embodiment of the formed suspension panel with a plurality of corrugations in the center of the panel. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A vehicle seat assembly of the present invention having a formed suspension panel is shown in FIG.  1  and designated generally at  10 . The seat assembly  10  includes a lower generally horizontal seat bottom  12  and a generally upright seat back extending upwardly at the rear end of the seat bottom  12 . The seat bottom  12  includes a frame  16  (FIG. 2) which is mounted to a slide track  18 . The slide track  18  includes a fixed rail  20  adapted to be mounted to a motor vehicle body and a slide rail  22  which moves fore and aft upon the fixed rail  20  for adjustment of the fore and aft position of the seat assembly within the motor vehicle. 
     With reference to FIGS. 1 and 2, the seat back includes a back frame  24  which, as shown in FIG. 2, has upright frame side members  26  on each side of the seat and an upper frame cross member  28  at the upper end of the seat back. The seat bottom frame  16  is similarly constructed with frame side members  30  extending along each side of the seat and a front frame cross member  32 . The seat bottom frame and seat back frame are joined together through a recliner mechanism shown schematically at  34 . The invention does not require any particular frame structure for the seat bottom and seat back. Those shown are merely exemplary of many possible frame configurations. 
     The seat bottom includes formed suspension panel  36  which is attached to the frame  16 . The suspension panel  36  supports a resilient seat pad  38 . A trim cover  40  covers the pad  38  and is shown in this embodiment wrapping around the frame  16  and attached to the bottom side of the frame by any one of a variety of known attachments. 
     The seat back is similarly constructed with a trim cover  42 , a resilient pad (not shown) and a suspension panel  44 . The suspension panel  44  of the seat back is attached to the back frame  24  and provides support to the resilient pad of the seat back. The panel  44  is formed with a forwardly projecting lower portion  46  in the lumbar region of the seat back to provide additional support to the pad in the lumber region of the seat back. As shown in FIG. 1, the forwardly projecting lower end portion  46  of the back panel results in a corresponding recess at the lower end of the back panel when viewed from behind the seat assembly. This provides increased knee room for a person seated behind the seat assembly  10 . Other raised or forwardly extending portions of the panel can be provided to provide different degrees of support to the pad at various locations within the seat back. For example, the panel can be raised along the side edges of the seat back to increase support in the bolster region of the seat back. 
     The panel  44  is attached to the frame with any of a variety of means including the fasteners  48  shown on the back of the seat assembly in FIG.  1 . The fasteners  48  can be threaded fasteners, snap fasteners, etc. In addition, the panel  44  can be made with integral projections which insert into apertures in the seat back frame if desired. The seat back suspension panel  44  provides suspension and support to the seat pad as well as forming a back trim panel for the seat back. This reduces the number of components in the seat assembly. No longer is a separate spring wire suspension needed in the seat back. Instead, the suspension panel  44  serves both the suspension function as well as the decorative trim for the rear surface of the seat back. 
     In case of the seat bottom, the panel  36  provides the suspension support to the seat pad  38 . The panel  36  is formed with different grooves or corrugations  50  to provide different degrees of support and flexibility to the panel  36 . Alternative embodiments are shown in FIGS. 3 and 4 where the seat bottom suspension panel is shown with the different configurations to provide different degrees of flexibility and suspension support to the seat pad. 
     The degree of flexibility in the panel is designed in conjunction with the size, shape, thickness, density etc. of the resilient seat pad to achieve a desired degree of cushioning and comfort for a seat occupant. A variety of configurations can be used as illustrated in FIGS. 2,  3  and  4 . 
     With reference to FIG. 3, an alternative embodiment of the seat suspension panel of the present invention is shown. A suspension panel  52  is shown which is a single piece formed panel having a seat bottom portion  54  and seat back portion  56 . The two portions are joined together by a living hinge region  58 , allowing the bottom and back portions to flex relative to one another as the seat back is reclined to various positions. The seat bottom portion is configured with a generally U-shaped recessed portion  60  which corresponds to the buttock region of the seat occupant to provide a greater degree of flexibility in this region of the panel as compared to other regions of the panel for improved comfort. The seat back again has a forwardly projecting lower end portion  62  to provide increased lumbar support. 
     The suspension panel is made of a fibrous bat impregnated with a binder resin or thermoplastic fibers. The fibers are preferably non-woven and are randomly oriented. The fibers are needled to cause them to intermesh and then to orient them generally transversely to the planes of the surfaces of the bat. The fibers used in the bat are preferably thermoformable. It is desirable that they take a set when placed in a heated mold in the case of the thermoset resin or in a cold mold with thermoplastic so that they hold a three-dimensional configuration. Thermoplastic fibers are preferred, though their melting point should be substantially greater than the temperatures to which the end product may be exposed in intended use. Non-woven polyester fiber is a particularly preferred material in forming the non-woven fibrous bat because of its excellent elongation and molding characteristics at molding temperatures. Other fibers which could be employed include nylon, polypropylene and polyethylene such as polyethylene terephthalate (PET). 
     The binder resin that impregnates the bat adheres the fibers to one another. The binder resin must be thermoformable to accommodate the molding process. This requires a thermoplastic or equivalent material. A binder resin may be selected from the group including: water dispersed urethane, acrylic, ethylene vinyl acetate acrylic, styrene butadiene rubber, polyvinyl acetate, polyvinyl acrylic copolymer, epoxy and water-based styrene. 
     The impregnating binder resin of the bat can also be a thermoset resin which provides an advantage that once it is cured, it will have very high resistance to heat distortion or deterioration. The thermoset resin is preferably elastomeric in nature so that the suspension panel has elastic characteristics. A preferred thermosetting elastomeric resin is elastomeric urethane. 
     An alternative material for the suspension panel, other than a resin impregnated fibrous bat, is a blend of organic fibrous materials known as a kenaf, which is the ground up stalk fibers of the hibiscus plant. These fibers are blended with polypropylene in a mixture that can range from about 40% kenaf to 60% polypropylene fibers by weight to a mixture of about 60% kenef and 40% polypropylene fibers. The polypropylene is in a fibrous form and the kenef and polypropylene fibers are mixed in a conventional pin cylinder mixer and subsequently oriented and formed into a web using a conventional airlay machine to initially orient the fibers longitudinally and subsequently, by a standard needling machine to entangle the fibers. The result is a web of somewhat fluffy mat-material which is then heated to melt the polypropylene fibers. The heated mat is placed into a cold tool, compressed and formed into the desired shape. Instead of kenef fibers, other plastic fibers can be used that have a melting point higher than the polypropylene fibers. 
     During the forming process of the suspension panel, a decorative cover sheet can be applied to the panel prior to the thermoforming of the panel. For example, a decorative fabric can be applied to the rear surface of the panel used in the seat back to provide an attractive appearance to the rear of the seat back. Preferably, the fiber of the decorative cover would also be thermoformable so that the cover can be applied to the uncured resin of the bat prior to thermoforming. The resin, once cured, serves as the adhesive to bond the decorative cover in place on the suspension panel. A particular preferred thermoformable polymeric fabric cover sheet comprises a nylon or polyester warp knit cloth material. 
     It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.