Patent Publication Number: US-8995138-B2

Title: Assembly including a compression-molded, composite panel with a hinged mounting flange

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of both U.S. patent application entitled “Carpeted Automotive Vehicle Load Floor Having a Living Hinge” filed Apr. 23, 2012 and having U.S. Ser. No. 13/453,201 and U.S. patent application entitled “Method of Making a Sandwich-Type Composite Panel Having a Living Hinge and Panel Obtained by Performing the Method” also filed Apr. 23, 2012 and having U.S. Ser. No. 13/453,269, both of which are incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD 
     This invention relates, in general, to the field of compression-molded, composite panels and, in particular, to assemblies including such panels with hinged mounting flanges. 
     Overview 
     Sandwich-type composite panels including cores have very important characteristics because of their light weight and high strength. Conventionally, such panels are constructed by sandwiching a core having a large number of cavities and having low strength characteristics between two outer layers or skins, each of which is much thinner than the core but has excellent mechanical characteristics. 
     The prior art discloses a method of making a panel of sandwich-type composite structure having a cellular core in a single processing step. In that method, the panel is made by subjecting a stack of layers of material to cold-pressing in a mold. As shown in  FIG. 1 , the stack is made up of: at least a first skin made of a reinforced thermoplastics material, a cellular core made of a thermoplastics material, and a second skin also made of a reinforced thermoplastics material. The stack may also include one or more external covering layers made of a woven or nonwoven thermoplastic material. The skins may be pre-heated outside the mold or heated inside the mold to a softening temperature. 
     Such a method is particularly advantageous because of the fact that it makes it possible, in a single operation, to generate cohesion and bonding between the various layers of the composite structure as shown in  FIG. 2 , and to shape the resulting panel while preserving all of the mechanical properties imparted by the cellular-core, sandwich structure. 
     Panels of sandwich-type composite structure having a cellular core have rigidity characteristics sufficient to enable mechanical structures subjected to large stresses to be reinforced structurally without making them too heavy. Such panels are in common use in shipbuilding, aircraft construction, and rail vehicle construction. 
     To maximize the functionality of such panels, it is known, in particular, that hinges can be added so that the panels can be hinged to other panels. Such hinges typically are separate parts that are fixed to the panels by gluing, welding, riveting, or some other fastening technique. 
     Such hinges are fixed to the sandwich-structure composite panels in a separate and subsequent operation, after said panels have been formed. That subsequent operation requires an additional workstation, be it automated or otherwise, which increases, in particular, the manufacturing time and cost of the finished parts. 
     In addition, the fact that separate, external parts are mounted on a composite panel of the sandwich-type is a source of quality defects, and thus adds to the cost of making such panels. 
     Published U.S. Patent Application 2005/0189674 discloses a method of making a composite panel of sandwich structure provided with a hinge. The panel includes a stack made up of a first skin of a reinforced thermoplastics material, a cellular core made of a thermoplastics material, and a second skin made of a reinforced thermoplastics material. The panel is formed by pressing the stack in a mold. The first and second skins are preheated to a softening temperature. As shown in  FIGS. 3 and 4 , after the panel has formed, an incision is made at a determined place in the panel so as to cut through one of the first and second skins, and substantially through the entire thickness of the cellular core, while leaving the other skin intact so that it forms a living hinge between two portions of the incised panel. 
     Other U.S. patent documents related to the present invention include: U.S. Pat. No. 5,298,694; U.S. Pat. No. 5,502,930; U.S. Pat. No. 5,915,445; U.S. Pat. No. 5,979,962; U.S. Pat. No. 6,050,630; U.S. Pat. No. 6,102,464; U.S. Pat. No. 6,435,577; U.S. Pat. No. 6,537,413; U.S. Pat. No. 6,631,785; U.S. Pat. No. 6,655,299; U.S. Pat. No. 6,659,223; U.S. Pat. No. 6,682,675; U.S. Pat. No. 6,793,747; U.S. Pat. No. 6,748,876; U.S. Pat. No. 6,790,026; U.S. Pat. No. 6,682,676; U.S. Pat. No. 6,823,803; U.S. Pat. No. 6,843,525; U.S. Pat. No. 6,890,023; U.S. Pat. No. 6,981,863; U.S. Pat. No. 7,014,259; U.S. Pat. No. 7,090,274; U.S. Pat. No. 7,093,879; U.S. Pat. No. 7,264,685; U.S. Pat. No. 7,320,739; U.S. Pat. No. 7,402,537; U.S. Pat. No. 7,419,713; U.S. Pat. No. 7,837,009; U.S. Pat. No. 7,909,379; U.S. Pat. No. 7,918,313; U.S. Pat. No. 7,919,031; U.S. Pat. No. 8,117,972; 2006/0255611; 2008/0185866 and 2011/0315310. 
     One problem associated with prior art assemblies having such panels as load floors in the automotive industry is that the assemblies typically require many assembly steps often involving costly labor which adds to the cost and time of assembly manufacture. Also, some of the materials making up such assemblies are often non-recyclable. 
     Some panel assemblies such as load floor assemblies have components which are pivotable with metal hinges. However, such hinges are often unsightly and heavy and the components are difficult and unwieldly to pivot with a single hand. 
     SUMMARY OF EXAMPLE EMBODIMENTS 
     An object of at least one embodiment of the present invention is to provide an assembly, such as a vehicle floor panel assembly, including a pivotable component, which is light-weight, and aesthetically pleasing wherein a hinged mounting flange of the assembly is capable of withstanding repeated cyclic loading. 
     In carrying out the above object and other objects of at least one embodiment of the present invention, an assembly including a compression-molded, composite panel is provided. The panel includes first and second outer layers and a core having first and second portions positioned between the outer layers. The first portion of the core has a large number of cavities and the second portion of the core is substantially free of cavities. The second outer layer is bonded to the core by press molding. The first outer layer includes a first portion bonded to the first portion of the core by press molding and a second portion bonded to the second portion of the core to form a mounting flange pivotally connected to the first portion of the first outer layer. The assembly also includes a component mounted to the mounting flange to pivot with the mounting flange. The assembly further includes a living hinge which allows the mounting flange and the mounted component to pivot between different use positions relative to the first portion of the first outer layer. 
     The assembly may include at least one fastener for fastening the component to the mounting flange. 
     Each fastener may be a threaded fastener wherein the component includes a threaded part to hold the threaded fastener to the component. 
     The mounting flange may include at least one hole which extends completely through the mounting flange. Each fastener may be externally threaded. The threaded part may include an internally threaded hole. Each fastener may extend through its corresponding hole in the mounting flange and be threadedly secured within its internally threaded hole. 
     The assembly may further include a substantially continuous carpet layer bonded to an upper surface of the first outer layer including the first and second portions of the first outer layer to at least partially form a carpeted composite panel having a carpeted mounting flange. The living hinge may include a portion of the carpet layer. 
     The first outer layer may be made out of polymeric material wherein the living hinge is at least partially made out of the polymeric material. 
     The assembly may further include a second living hinge which facilitates or allows the mounting flange and the mounted component to pivot between the different use positions. 
     The assembly may further include a substantially continuous carpet layer bonded to an outer surface of the first outer layer including the first and second portions of the first outer layer to at least partially form a carpeted composite panel having a carpeted mounting flange. Each of the first and second living hinges may include a portion of the carpet layer. 
     A portion of the mounted component may have a reduced thickness to form a depression which receives the mounting flange. 
     A portion of the mounted component may have a reduced thickness to form a depression which receives the carpeted mounting flange wherein thickness of the carpeted mounting flange is substantially equal to depth of the depression. 
     The first outer layer including the first and second portions may be a fiber-reinforced, thermoplastic layer. 
     Further in carrying out the above object and other objects of at least one embodiment of the present invention, a vehicle assembly including a compression-molded, composite panel with a hinged mounting flange is provided. The panel includes first and second fiber-reinforced, outer layers and a core having first and second portions positioned between the outer layers. The first portion of the core has a large number of cavities and the second portion of the core is substantially free of cavities. The second outer layer is bonded to the core by press molding. The first outer layer has an outer surface and includes a first portion bonded to the first portion of the core by press molding and a second portion bonded to the second portion of the core to form a mounting flange pivotally connected to the first portion of the first outer layer. The assembly also includes a component mounted to the mounting flange to pivot with the mounting flange within the interior of the vehicle. The assembly further includes a living hinge which allows the mounting flange and the mounted component to pivot between different use positions relative to the first portion of the first outer layer. 
     The assembly may include a carpet layer such as a thermoplastic carpet layer bonded to the load bearing surface of the first outer layer. The thermoplastic of the first outer layer including the first and second portions and the carpet layer may be polypropylene. 
     The composite panel may have a thickness in the range of 5 to 25 mm. 
     The outer layers may be fiber-reinforced thermoplastic layers wherein the first outer layer has a load bearing surface. 
     The core may be a cellular core. 
     The core may have a honeycomb structure. 
     Still further in carrying out the above object and other objects of at least one embodiment of the present invention, a vehicle floor panel assembly is provided. The assembly includes a compression-molded panel including first and second fiber-reinforced, outer layers and a core having first and second portions positioned between the outer layers. The first portion of the core has a large number of cavities and the second portion of the core is substantially free of cavities. The second outer layer is bonded to the core by press molding. The first outer layer has a load-bearing surface and includes a first portion bonded to the first portion of the core by press molding and a second portion bonded to the second portion of the core to form a mounting flange pivotally connected to the first portion of the first outer layer. The assembly also includes a component mounted to the mounting flange to pivot with the mounting flange in an interior of the vehicle. The assembly further includes a living hinge which allows the mounting flange and the mounted component to pivot between different use positions relative to the first portion of the first outer layer. 
     A portion of a carpet layer bonded to the load-bearing surface of the first outer layer may at least partially form the first living hinge. A second portion of the carpet layer may at least partially form the second living hinge. 
     Other technical advantages will be readily apparent to one skilled in the art from the following figures, descriptions and claims. Moreover, while specific advantages have been enumerated, various embodiments may include all, some or none of the enumerated advantages. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side sectional view showing various separate layers of a prior art stack of thermoplastic-based layers of material; 
         FIG. 2  is a top perspective sectional view of the stack of  FIG. 1  after compression molding; 
         FIGS. 3 and 4  are side views, partially broken away and in cross section, of a prior art sandwich-type composite panel having a living hinge and method of making the living hinge; 
         FIG. 5  is an environmental view, partially broken away, of a carpeted automotive vehicle load floor including a pair of carpeted, sandwich-type, compression-molded, composite panel assemblies each being constructed in accordance with at least one embodiment of the present invention; 
         FIG. 6  is a side view, partially broken away and in cross section, of one embodiment of one of the panel assemblies taken along lines  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a view, similar to the view of  FIG. 6 , but showing a second embodiment of one of the panel assemblies taken along lines  7 - 7  of  FIG. 5 ; and 
         FIG. 8  is a view, similar to the views of  FIGS. 6 and 7 , but showing a third embodiment of one of the panel assemblies taken along lines  8 - 8  of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
     Referring now to the  FIGS. 5 ,  6 ,  7 , and  8  different embodiments of an assembly including a compression-molded composite panel with a hinged mounting flange are provided. In one example embodiment, a carpeted automotive vehicle load floor, generally indicated at  13 , includes a pair of carpeted, compression-molded, sandwich-type, composite hinged panel assemblies, generally included at  10 . In one example embodiment, the assembly  10  ( FIG. 6 ) has a single living hinge  12 . In a second example embodiment, the assembly  10  ( FIG. 7 ) has a single living hinge  12  and an elongated top decorative depression  46 . In a third example embodiment, the assembly  10  ( FIG. 8 ) has a pair of spaced apart living hinges  12 ′. However, it is to be understood that one or more panel assemblies  10  constructed in accordance with at least one embodiment of the present invention may be used in a wide variety of environments besides the automotive vehicle environment of  FIG. 5 . 
     Each panel of the panel assembly  10  ( FIGS. 6 ,  7  and  8 ) is typically manufactured by providing a stack of materials located or positioned within a mold. The stack includes first and second reinforced thermoplastic skins or outer layers  20  and  22 , respectively, a core having a large number of cavities such as a thermoplastic cellular core  24  disposed between and bonded to the skins  20  and  22  by press molding within the mold. A substantially continuous covering or carpet layer  26  made of thermoplastics material covers and is bonded to the first skin  20  which provides a top carpeted support surface. The skins  20  and  22  are heated typically outside of the mold to a softening temperature. The mold is preferably a low-pressure, compression mold which performs a thermo-compression process on the stack of materials. 
     The outer skin  20  is divided into a first portion bonded to a first portion of the core  24  and a second portion bonded to a second portion  30  of the core  20  which is substantially free of cavities (i.e. is substantially solid) to at least partially form a mounting flange  28  pivotally connected to the first portion of the skin  20  by the living hinge  12 . In other words, as shown in  FIGS. 6 ,  7  and  8 , the outer skin  20  is divided into a first portion bonded to the first portion of the core  20  (which has cavities) and a second portion bonded to a second portion of core  20  (which is substantially solid) to at least partially form the mounting flange  28  pivotally connected to the first portion of the skin  12  by the living hinge(s) ( 12  or  12 ′). 
     The assembly  10  also includes a component such as a thermoplastic component, generally indicated at  32 , which is mounted to the mounting flange  28  to pivot with the mounting flange  28  about the living hinge  12 . The living hinge  12  allows the mounting flange  28  and the mounted component  32  to pivot between different use positions relative to the first (right most as shown in  FIGS. 6-8 ) portion of the first layer  20 . 
     A portion  36  of the thermoplastic carpet layer  26  covers and is bonded to an upper surface of a plastic part  34  of the component  32  to provide an upper carpeted support surface. An intermediate portion of the layer  26  at least partially forms the living hinge  12 . The living hinge  12  allows the carpeted mounting flange  28  to pivot between the different use positions. 
     The assembly  10  (of  FIGS. 6 ,  7  and  8 ) may also include at least one threaded or non-threaded fastener for fastening the component  32  to the mounting flange  28 . The fastener may be any of various devices for fastening the component  32  to the mounting flange  28  such as an externally threaded screw  40  or bolt. The screw  40  is characterized by a helical ridge, or external thread, wrapped around a cylinder. The screw threads mate with a complementary thread or internal thread in the part  34 . The internal thread may be in the form of a nut or an object that has the internal thread formed into it. The screw thread may also cut a helical groove in the softer material of the part  34  as the screw  40  is inserted. The head of the screw  40  is preferably decorative. 
     Each screw  40  may be made from a wide range of materials, with steel being perhaps the most preferred, in many varieties. Where great resistance to corrosion is required, stainless steel, titanium, brass, bronze, monel or silicon bronze may be used. Galvanic corrosion of dissimilar metals can be prevented by a careful choice of material. 
     Some types of plastic, such as nylon or polytetrafluoroethylene (PTFE), can be threaded and used for fastenings requiring moderate strength and great resistance to corrosion or for the purpose of electrical insulation. A surface coating may be used to protect the fastener from corrosion (e.g. bright zinc plating for steel screws), to impart a decorative finish (e.g. jappaning) or otherwise alter the properties of the base material. Selection criteria of the screw materials include temperature, required strength, resistance to corrosion, joint material and cost. 
     The panel assembly  10  may also include a plastic mounted support or bar  35  which extends across the width of the storage area under the assembly  10  to support the component  32  and the panel of the assembly  10  at the living hinge(s)  12  or  12 ′. 
     The carpet layer  26  may be a resin carpet and the resin may be polypropylene. The carpet layer  26  may be made of a woven or nonwoven material (typically of the carpet type). 
     Referring now to  FIG. 7 , a second embodiment of an assembly is generally indicated at  10 . The assembly  10  is substantially identical to the assembly  10  of  FIG. 6  but includes a top and relatively deep decorative depression  46  formed during the compression molding process by a projection supported or suspended at the inner mold surface of an upper mold half. 
     Referring now to  FIG. 8 , a third embodiment of an assembly is generally indicated at  10 . The parts of the assembly  10  which are the same in either structure and/or function to the parts of  FIGS. 6 and 7  have the same reference number. In general, the assembly  10  of  FIG. 8  differs from the assembly of  FIG. 6  by having two living hinges  12 ′ with a mounting flange  28  and a decorative depression  46 ′ to further facilitate or allow the carpeted mounting flange  28  and mounted component  32  to pivot between different use positions. Also, while shown solid, the part  34  may be hollow to provide a component  32  which may be lighter in weight than the solid part  34  of  FIGS. 6 ,  7 , and  8 . 
     The cellular core  24  may be a honeycomb core. In this example, the cellular core  24  has an open-celled structure of the type made up of tubes or a honeycomb, and it is made mainly of polyolefin and preferably of polypropylene. It is also possible to use a cellular structure having closed cells of the foam type. 
     The member or component  32  may be made of a different material(s) to which the portion  36  of the carpet layer  26  is bonded. 
     Each of the skins  20  and  22  of each of the assemblies  10  may be fiber reinforced. The thermoplastic of the skins  20  and  22 , the covering carpet layer  26  and the core  24  may be polypropylene. At least one of the skins  20  and  22  may be a woven skin, such as polypropylene skin. Each of the skins  20  and  22  may be reinforced with fibers, e.g., glass fibers, carbon fibers or natural fibers. At least one of the skins  20  and  22  may advantageously be made up of woven glass fiber fabric and of a thermoplastics material. 
     Each resulting hinged panel assembly  10  may have a thickness in the range of 5 to 25 mm. A depression  38  formed in the part  34  and in which the mounting flange  28  is secured may have a depth in the range of 2 to 10 mm. 
     In one example method of making the hinged panel assembly  10  including the mounting flange  28 , stacks of material are pressed in a low pressure, cold-forming mold. With respect to a first part of the hinged panel assembly  10 , the stack is made up of the first skin  20 , the cellular core  24 , the second skin  22  and a portion of the covering layer  26 , and the stack is pressed at a pressure lying in the range of 10×10 5  Pa. to 30×10 5  Pa. The first and second skins  20  and  22  are preferably pre-heated to make them malleable and stretchable. Advantageously, in order to soften the first and second skins  20  and  22 , respectively, heat is applied to a pre-assembly constituted by the stack made up of at least the first skin  20 , of the cellular core  24 , and the second skin  22  so that, while the first part of the panel of the assembly  10  is being formed in the mold, the first and second skins  20  and  22  have a forming temperature lying approximately in the range of 160° C. to 200° C., and, in this example, about 180° C. In like fashion, the mounting flange  28  may be formed. However, in forming the mounting flange  28 , the living hinge  12  (or hinges  12 ′) may be formed by performing the method of the above-noted patent application entitled “Method of Making a Sandwich Type Composite Panel Having a Living Hinge and Panel Obtained by Performing the Method.” 
     The covering carpet layer  26  is substantially continuous and may be formed from separate pieces of thermoplastic resin carpet which are subsequently bonded or fused together, such as by heat and/or pressure to carpet the entire top support surface of the hinged panel assembly  10 . 
     In summary,  FIGS. 6 ,  7  and  8  show first, second and third embodiments, respectively, of a carpeted, sandwich-type, composite hinged panel assembly  10 . The assemblies  10  have basically the same structure and function except in the first embodiment of  FIG. 6  a single living hinge  12  is provided, in the second embodiment a single living hinge  12  with a deep decorative groove  46  are provided and in the third embodiment a pair of living hinges  12 ′ with a shallow depression  46 ′ are provided. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.