Structural foamed panel and method of making the same

Abstract

A panel or multi-panel structure in which each of the panels includes a pair of spaced substantially planar sheets connected with one another by connection members and a foam core.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structural panel for use by numerous markets including the Department of Defense. These lightweight components are used as structural members on items such as vehicles and radar structures. The combination of lightweight (metallic, plastic, composite) member and a lightweight foam application that is applied in the open cavity produces favorable results for these customers. These panels are typically custom designed to the customer's application/shape, monolithic/high velocity machined, fastened together via new technology and then foamed. There is also a benefit with the thermal/acoustic characteristics that this product provides for insulating certain components. The invention also relates to the numerous combined methods of manufacturing and fastening the components.

2. Description of the Prior Art

The need for force mobility in the Armed Services (along with fuel costs) is driving development of a new generation of lightweight material solutions. Many earlier systems and components were built very heavy with thick metallic cross sections for safety and performance benefits. The introduction of new high velocity machining technology has now given manufacturers the option for thinner, lighter components if they can meet the structural/stress requirements. Many of these earlier components were also fastened with heavy bolts and rivet type hardware, further increasing the weight of a vehicle or system. Composites have been a costly lightweight alternative that have numerous manufacturing issues from expensive/complex tooling needs to distortion, disposal and repair of base composite.

SUMMARY OF THE INVENTION

The present invention relates to a structural component or panel and multi-panel structure that utilizes various new manufacturing methods to produce a strong, lightweight composite alternative. This invention is lighter than traditional aluminum structures and less expensive than current composite components.

The present invention can be comprised of a single metallic component or panel or multiples depending on the design needed. These components or panels are machined from blocks of material utilizing the latest monolithic grid and thin walled processes in the marketplace. Surface treatments are then specified based on the fastening and adherence requirements. The panels can then be foamed before fastening or after. Many of these panels will utilize quick connection systems such as the connection system of pending U.S. patent application Ser. No. 11/094,331 filed Mar. 30, 2005 (hereinafter “Pending Connection Mechanism”), the entirety of the substance of which is incorporated herein by reference. Many may also utilize friction stir welding or epoxy processes to join the multiple pieces. Once the core is foamed, additional precision machining can be accomplished to add critical features or to further thin or machine walls and surfaces. The form core acts as a support to allow thinning of certain features, further reducing weight. These components can also contain cooling components (cold plates) and other structural features for mounting, coolant passage, or component clearance depending on design needs. Contoured or multi-axis surfaces and features will also be attainable with this invention.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a pair of structural panels made in accordance with the present invention. The component at the bottom includes a pair of aluminum plates filled with foam and a pair of connection rails at the top. The upper component includes a pair of spaced aluminum plates with foam therebetween and a base designed for connection to the connection rails. The rails form a connection mechanism similar to that of the Pending Connection Mechanism.

FIG. 2 is a top view showing a portion of a structural panel of FIG. 1 in accordance with the present invention connected with a base plate. The structural panel includes a web with radii mating with the surface plates. The area between the surface plates is filled with a foam.

FIG. 3 is comprised of FIGS. 3a and 3b. These figures are perspective views showing a pair of panel structures similar to those shown in FIGS. 1 and 2.

FIG. 4 is comprised of FIGS. 4a and 4b. These figures are perspective views showing the panel structures of FIGS. 1-3 in which the vertically positioned panel is connected with the base panel.

FIG. 5 is a further embodiment of a structural panel in accordance with the present invention, shown in cross-section. The top surface panel is integrally connected with a pair of struts and an end wall, while the bottom surface panel is connected with the struts via the Pending Connection Mechanism. The core is filled with foam.

FIG. 6 is a view, partially in section, of a base panel and a pair of integral, laterally spaced struts and an integral end wall. The top surface panel is connected with the struts via a pair of threaded members and is connected to the end wall by the above-described Pending Connection Mechanism. The interior cores between the plates and the struts are filled with a foam material.

FIG. 7 is a further embodiment of a structural panel in accordance with the present invention in which the bottom aluminum surface panel is integrally formed with an end wall and a partial front wall. The top surface panel is connected with the end wall and the partial front wall via the above-described Pending Connection Mechanism. The area between the panels is filled with a foam.

FIG. 8 is a view, partially in section, of a further embodiment of the structural panel of the present invention. The base surface panel is integrally formed with a pair of struts and an end wall and the top surface panel is connected with the struts and the end wall via the Pending Connection Mechanism. The interior cores are filled with foam material.

FIG. 9 is comprised of FIG. 9a and FIG. 9b. FIG. 9b is a sectional view showing the structure of a typical structural panel in accordance with the present invention with the base surface sheet integrally formed with a vertically extending strut and with the top surface sheet having a pair of prongs or connection members to connect with the distal end of the strut. The connection system between the top surface sheet and the strut is in accordance with the above-described Pending Connection Mechanism. The cores within the panels are filled with a foam. FIG. 9b shows the connection members before connection.

FIG. 10 is a view showing relative dimensions in one embodiment of a structural foam panel between the aluminum and the foam.

FIG. 11 is a sectional view of an embodiment of the present invention similar to the embodiment of FIGS. 1-4. This embodiment comprises a lightweight foam or monolithic configuration.

FIG. 12 is a perspective view of an embodiment of the foam core structure shown in FIGS. 1-4.

FIG. 13 is an enlarged view of the connection between an edge of a vertical panel structure and the outer surface of a base panel structure of the embodiment of FIGS. 1-4. This connection utilizes the Pending Connection Mechanism in which a pair of connection prongs or connection members are integrally formed with the outer surface panel of the base for connection with prongs of the vertical panel.

In the above embodiments, all panel components are constructed of aluminum or other lightweight metals such as titanium and the cores are filled with a curable foam.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is directed to a structural component or panel in which a pair of sheets are connected to one another via one of a variety of connection mechanisms such as those disclosed in pending U.S. patent application Ser. No. 11/094,331 filed Mar. 30, 2005, the entirety of the substance of which is incorporated herein by reference. Such structural components or panels are then filled with a foam core to provide a lightweight, high strength structural component or panel. The invention is also directed to a method of making such a panel and to a multi-panel structure in which two or more panels are connected together.

In the preferred embodiment, portions of a panel or multiple panels are connected to one another utilizing the connection mechanism techniques described and disclosed in the above-mentioned pending U.S. patent application Ser. No. 11/099,331. The connection mechanism disclosed therein generally includes a pair of female connecting members or surfaces and a corresponding pair of male connecting members or surfaces which are capable of being mechanically interlocked with one another as a result of grooves or recesses on one of the members or surfaces and corresponding connection ribs on the other.

FIGS. 9 and 13 show examples of such connection mechanisms. FIGS. 9a and 9b show the connection of a first or lower substantially planar sheet 10 with a second or upper spaced substantially planar sheet 11 to form the panel 12. As shown, the sheet 10 includes one or more outwardly extending struts 14 integrally formed with the sheet 10. The outer end 15 comprises an enlarged head with connection surfaces facing away from one another. The connection surfaces include shoulder portions 16 which transition to the narrower strut portion 14. The opposite, spaced sheet 11 includes a female portion comprised of the pair of connection members 18. These members 18 include inwardly facing connection surfaces which include the enlarged portion or rib 19. When the sheet 11 is positioned relative to the sheet 10 so that the members 18 are aligned with the portion 15 as shown in FIG. 9b and pressed together, the head portion 15 is inserted between the members 18 and is retained in that position by engagement between the ribs 19 and the shoulders 16. If desired, this mechanical connection can then be further joined and retained by a secondary connection mechanism such as epoxy, friction stir welding or other means. If epoxy is used, one or the other or both of the inside of the members 18 or the outside of the members 15 and 16 is provided with an epoxy adhesive prior to snapping the two parts together. If a secondary connection mechanism such as friction stir welding is utilized, friction stir welding may be applied along the area indicated by the reference character 20 in FIG. 11a. Although the panel formed by the sheets 10 and 11 shows only a single strut 14, it is contemplated that a typical panel will include a plurality of struts 14 positioned near the ends of the panel and laterally spaced throughout the panel. It is intended that the panel will also include edges between and around the periphery of the sheets.

FIG. 13 shows a preferred mechanism for connecting an edge of one panel 21 to the surface of a second panel 22. As shown, the panel 22 to which the panel 21 is to be connected includes a first substantially planar sheet 24 and a second substantially planar sheet 25. The outer surface of the sheet 25 includes a pair of spaced connection members 26 extending outwardly from the outer surface of the sheet 25. Each of these members 26 includes a pair of connection surfaces having a widened rib portion 28 facing the other member 26. The edge of the panel 21 to be connected to the panel 22 includes a male member comprised of a pair of spaced connection surfaces 29 facing away from one another. The surfaces 29 include a pair of grooves or recessed areas 30. When the panel 21 is positioned relative to the panel 22 so that the edge 23 is aligned between the members 26, the surfaces 29 slide between the members 26 and the shoulders or enlarged areas 28 snap into the grooves 30, thereby retaining the panel 21 relative to the panel 22. If additional connection means are needed or desired, epoxy, friction stir welding or other connection techniques may be utilized. If friction stir welding is to be utilized, it may be applied between one or both of the members 26 and a corresponding portion of the surface 29 or groove 30 as shown by the reference character 31 in FIG. 13.

Having described the details of the connection mechanisms and techniques between a pair of sheets to form panels and between a pair of panels to form a multi-panel structure, specific structural components and panels can be described with respect to the remaining figures as follows.

In FIG. 1, an edge 32 of the foamed panel 34 is connected to the top outer surface 35 of the foamed panel 36. As shown, the outer surface 35 of the panel 36 is provided with a pair of outwardly extending connection members 38,38 to mate with corresponding surfaces 39,39 of the panel edge 32. In this embodiment, the connection members 38,38 and the connection surfaces 39,39 are similar in detail to those shown in FIG. 15.

FIG. 2 shows a foamed panel 40 with a bottom edge connected to a base plate 41. In this embodiment, the base plate 41 may be the outer surface of a second foamed panel or a single sheet of material. As shown in this figure, the panel 40 is provided with a web 42 to provide additional strength and rigidity to the panel 40. The edge of the panel 40 and the surface of the base plate 41 which are connected to one another are provided with a connection mechanism similar to that shown in FIG. 15.

FIG. 3 comprised of FIGS. 3a and 3b shows a pair of interconnected foamed panel structures similar to those of FIGS. 1 and 2. In FIG. 3a, an edge of the panel 44 is connected to an outer surface of the panel 45 utilizing a connection mechanism similar to that shown in FIG. 15. FIG. 3b shows an edge of the panel 46 connected with an outer surface of the panel 48 utilizing a connection mechanism of FIG. 15. In FIG. 3b, the panel 46 is provide with one or more reinforcing struts or webs 49 integrally formed with and positioned between the sheets of the panel 46.

FIG. 4 comprised of FIGS. 4a and 4b shows further examples of structural components formed by connecting an edge of one foamed panel to the outer surface of a second foamed panel. In FIG. 4a, an edge of the panel 50 is connected to an outer surface of the panel 51, while in FIG. 4b, an edge of the panel 52 is connected to an outer surface of the panel 54. In both embodiments, the connection mechanism is similar to that shown in FIG. 15.

FIG. 5 is a foamed panel comprised of spaced first and second sheets 55 and 56, respectively. The sheet 56 includes a pair of downwardly extending and integrally formed struts 58, while the bottom sheet 55 includes two pair of spaced connection members 59 which mate with the outer ends of the struts 58. The details of the connection portions and surfaces of the struts 58 and the members 59 are similar to those shown in FIGS. 11a and 11b for connecting sheets to form a panel. Following connection, the interior of the panel is foamed.

FIG. 6 shows a panel 64 comprised of a lower sheet 69, a spaced upper sheet 70 and a plurality of integral studs or struts extending upwardly from the sheet 69. The sheet 70 is connected with the studs via threaded connection members in the threaded openings 72. The side edges of the panel 64 are provided with a connection mechanism 63 similar to that shown in FIGS. 11 or 15.

FIG. 8 shows a pair of substantially planar sheets 74 and 75 connected together to form the panel 76. The panel structure of FIG. 10 is similar to that of FIG. 5 except that the panel sheets are reversed. The panel of FIG. 8 utilizes the connection mechanism shown in FIG. 11. The interior of the panel 76 and each of its interior chambers is foamed.

FIG. 10 shows the dimensional relationship between the sheets 78 and 79 and the foam core 80 of a typical panel 77 in accordance with the preferred embodiment. In the preferred embodiment, the foam which comprises the foam core of the various panel embodiments is a curable foam known in the art such as polyurethane, polyethylene and polystyrene, among others. Such foam is preferably introduced into the core of the panels through an opening in one of the panel sheets after the sheets have been connected to form the panel. In many cases, the port or opening for introducing the foam into the panel cores can be positioned between the connection members 26,26 such as is shown in FIG. 13.

FIG. 11 is a view, similar to claim 1, with panel 34 connected with the panel 36.

FIG. 12 is an isometric view of the structural panel shown in FIG. 13.

Although the preferred embodiment has been quite specific, it is contemplated that various modifications could be made without deviating from the spirit of the present invention. Accordingly, it is intended that the scope of the present invention be dictated by the appended claims rather than by the description of the preferred embodiment.

Claims

1. A structural panel comprising:

a first substantially planar sheet having an inner surface and an outer surface;

a second substantially planar sheet having an inner surface and an outer surface, said first and second sheets spaced from one another with their respective inner surfaces facing one another;

the inner surface of one of said first and second sheets including a first connection member extending therefrom and the inner surface of the other of first and second sheets including a second connection member extending therefrom, said first and second connection members being connectable to one another to maintain said first and second sheets in spaced relationship; and

a foam core between said paced first and second sheets.

2. The panel of claim 1 wherein one of said first and second connection members includes a plurality of struts extending between said first and second sheets.

3. The panel of claim 2 wherein one end of said struts is integrally formed with one of said first and second sheets.

4. The panel of claim 3 wherein the other end of said struts includes a head having a pair of connection surfaces.

5. The panel of claim 4 wherein the other of said first and second connection members is integrally formed with the other of said first and second sheets.

6. The panel of claim 5 wherein one of said first and second connection members includes a pair of connection surfaces facing toward one another and the other of said first and second connection members includes a pair of connection surfaces facing away from one another.

7. The panel of claim 6 including an edge extending between said sheets around the periphery of said sheets.

8. The panel of claim 1 including an edge extending between said sheets around the periphery of said sheets.

9. The panel of claim 1 including a plurality of laterally spaced webs between said sheets.

10. A method of making a structural panel comprising:

providing first and second substantially planar sheets;

connecting said first and second sheets to one another in spaced relationship; and

injecting a foam material between said first and second spaced sheets.

11. The method of claim 10 including forming an edge between said sheets and around the periphery of said sheets.

12. A multi-panel structure comprising:

a first foamed panel having a pair of spaced, substantially planar sheets, a plurality of connection members between said first and second sheets to connect said sheets to one another and maintain said sheets in a spaced relationship and a foam core between said sheets;

a second foamed panel having a pair of spaced, substantially planar sheets, a plurality of connection members between said first and second sheets to connect said sheets to one another and maintain said sheets in a spaced relationship and a foam core between said sheets;

one of said first and second panels including an outer surface having a pair of spaced first connection members extending outwardly from said outer surface;

the other of said first and second panels including a panel edge, said edge including spaced second connection members, said first and second connection members connectable to one another to connect the edge of said other panel to the outer surface of said one panel.

13. The structure of claim 12 wherein one of said first and second connection members includes a pair of connection surfaces facing toward one another and the other of said first and second connection members includes a pair of connection surfaces facing away from one another.

14. The structure of claim 13 wherein said first connection members includes a pair of connection surfaces facing toward one another and said second connection members includes a pair of connection surfaces facing away from one another.

15. The structure of claim 14 wherein one of pair of connection surfaces includes a connection rib and the other or said pair of connection surfaces includes a connection recess.

16. The structure of claim 15 wherein said connection ribs and said connection recesses are connectable to one another.