Abstract:
An expandable reinforcing member includes a first and a second member configured to move relative to each other and defining an interior cavity therebetween. An expandable material is inside the cavity. Upon activation, the expandable material expands and causes the first and second members to move relative to each other in a manner that reinforces a hollow structural member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a nonprovisional of U.S. Provisional Application Ser. No. 60/775,229, entitled EXPANDABLE REINFORCING MEMBER, filed Feb. 21, 2006 which is hereby incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD  
       [0002]     The following disclosure describes an expandable reinforcing member, and more particularly, an expandable reinforcing member for reinforcing a cavity.  
       BACKGROUND  
       [0003]     In many structural applications, it is desirable to provide structural members that are light-weight and yet have high-strength characteristics. One method of achieving light-weight and high-strength structural members is to start with a hollow outer structural member and insert a light-weight reinforcing member inside of the hollow structural member. One exemplary industry where such approach is well-known is the automotive industry, wherein a vehicle frame has several reinforced hollow structural members, such as hollow pillars and rails throughout the frame. Various reinforcing members are known, including those made from a substantially rigid member having structural expandable foam disposed on the outer peripheries of the rigid member for bonding the rigid member to the interior walls of the hollow structural member.  
         [0004]     For ease of manufacturing, it is desirable that a reinforcing member be able to be used in various different types of hollow structural members and that the tolerances not be too stringent. Accordingly, there is a need for alternative reinforcing members, with improved reinforcing performance characteristics, which can be used in various sized hollow structural members.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]     The features and inventive aspects of the present invention will become more apparent from the following detailed description, the appended claims, and the accompanying drawings, in which:  
         [0006]      FIG. 1  is a cross-sectional view of an expandable reinforcing member in an unexpanded orientation; and  
         [0007]      FIG. 2  is a cross-sectional view of the expandable reinforcing member of  FIG. 1  disposed inside a cavity in an expanded orientation. 
     
    
     DETAILED DESCRIPTION  
       [0008]     Referring now to the drawings, illustrative embodiments are shown in detail, Although the drawings represent the embodiments, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain an innovative aspect of an embodiment. Further, the embodiments described herein are not intended to be exhaustive or otherwise limit or restrict the invention to the precise form and configuration shown in the drawings and disclosed in the following detailed description.  
         [0009]     Referring now to  FIG. 1 , an expandable reinforcing member  10  is shown in an unexpanded orientation, The expandable reinforcing member  10  includes an inner member  30  at least partially disposed within an outer member  20 . The inner member  30  and the outer member  20  may be of any shape, size, and material adapted for reinforcing a cavity in a structure. In one embodiment, the inner member  30  and outer member  20  are substantially rigid and made from a plastic, such as nylon. The inner member  30  is also adapted to fit at least partially within the outer member  20  so that at least a portion of one or more walls of the inner member  30  and the outer member  20  are generally adjacent. The inner member  30  and the outer member  20  together form a hollow interior cavity. An expandable material  50  is inside of the hollow interior cavity. In one embodiment, the expandable material  50  is an expandable structural or baffle foam, such as those described in U.S. Pat. No. 6,649,243, Pat. No. 6,387,470, Pat. No. 5,266,133, U.S. Pat. No. 6,348,513 and Pat. No. 5,373,027 and that are commercially available from Sika Corporation of Madison Heights, Mich. under the tradenames SIKABAFFLE 240 and SIKAREINFORCER 912.  
         [0010]     A bonding material  40 , such as an epoxy adhesive or, alternatively, additional expandable material may be placed at a first outer periphery of the outer member  20  and a second outer periphery of the inner member  30  to minimize movement between the expandable reinforcing member  10  and the hollow structural member (such as a vehicle rail or pillar) in the installed and expanded orientation. Further, the epoxy adhesive ( 40 ) may be placed between the inner walls of the outer member  20  and the outer walls of the inner member  30  to minimize movement between the inner member  30  and the outer member  20 .  
         [0011]     The expandable reinforcing member  10  is adapted to telescopically expand within the cavity or the hollow structure when an expanding agent, such as heat is applied thereto. In one embodiment, heat is applied to the expandable material when a vehicle is “baked” in a painting station during assembly. The first inner cavity of the outer member  20  shares at least a portion of the same space as the second inner cavity of the inner member  30  in the unexpanded orientation as shown in  FIG. 1 . The expandable material  50  is disposed within the first cavity and the second cavity and is adapted to bond the outer member  20  to the inner member  30  in the expanded orientation. The epoxy adhesive  40  may be formulated to cure at the temperature of an e-coat oven, typically used in the automobile assembly process. However, any adhesive  40  is contemplated. The expandable material  50  may expand at least twice its original volume. In one embodiment, the expandable material  50  is heat activated, such that expansion begins when heat is applied.  
         [0012]     At least one attachment member  60  may be disposed anywhere on the outer periphery of the outer member  20 , the inner member  30 , or both. The attachment member  60  may be adapted to secure a portion of the expandable reinforcing member  10  to a predetermined location. The attachment member  60  may be secured to a wall of the hollow structural member to minimize the expandable reinforcing member  10  from moving from the predetermined location. In one embodiment, the attachment member  60  allows fixation of the assembly inside a hollow structure of an automobile pillar or rail.  
         [0013]     One method of assembly will be described, However, other methods of assembling the expandable reinforcing member  10  are contemplated. The expandable reinforcing member  10  is assembled by first placing the expandable material  50  inside the inner volume of the smaller inner member  30 . Adhesive or expandable material  40  is applied to the exterior walls of the inner member  30  and the outer member  20 . Adhesive or expandable material  40  is then applied to the interior walls of the outer member  20  that are adjacent the outer walls of the inner member  30 .  
         [0014]     The outer member  20  is then placed over the inner member  30  and the entire assembly  10  is positioned inside the cavity or a section of the hollow structure. The expandable reinforcing member  10  may be secured to at least a portion of the cavity or hollow section of the structure by any securement method including fasteners, rivets, clamping, and the like. When heat is applied to the structure inside an oven, the expandable material  50  expands, telescoping the outer member  20  away from the inner member  30 . The telescoping of the outer member  20  and the inner member  30  is sufficient to make contact with at least two walls  80  of the hollow structural member as shown in an expanded orientation in  FIG. 2 .  
         [0015]     Once the expandable reinforcing structure  10  is in the expanded orientation, the adhesive  40  and the expandable material  50  cures and adheres to the contacted surfaces, thereby bonding the expandable reinforcing structure  10  to the walls  80  of the hollow structural member. Further, the epoxy adhesive  40  between the inner member  30  and the outer member  20  cure and minimize movement between the inner member  30  and the outer member  20 . Once the expandable material  50  is cured, the expandable reinforcing member  10  adds significant structural strength to the hollow structural member.  
         [0016]     If no adhesive  40  is used, the stiffness and strength of the cavity or hollow structure having a cured expandable reinforcing member  10  disposed therein depends on the strength of the expandable material  50  and the strength of the material used for the outer member  20  and the inner member  30 . Adhesive  40  placed between the outer member  20  and the inner member  30 , when cured, may add strength to the expandable reinforcing member  10 .  
         [0017]     The preceding description has been presented only to illustrate and describe exemplary embodiments of the methods and systems of the present invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. The invention may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. The scope of the invention is limited solely by the following claims.