US20030001469A1

US20030001469A1 - Structural reinforcement and method of use therefor

Info

Publication number: US20030001469A1
Application number: US10/163,894
Authority: US
Inventors: Timothy Hankins; Douglas Larsen; Dennis Lowe; David Stolarski
Original assignee: L&L Products Inc
Current assignee: L&L Products Inc
Priority date: 2001-06-06
Filing date: 2002-06-04
Publication date: 2003-01-02

Abstract

The invention provides a structural reinforcement and method of use therefore. The structural reinforcement preferably includes a bracket and a reinforcement material attached to the bracket. The bracket may include flanges for assisting in attaching the reinforcement to a wall of an article of manufacture. Preferably, the reinforcement material is expandable to wet and bond to the wall of the article and is also curable to harden and strengthen the wall of the article.

Description

FIELD OF THE INVENTION

The present invention relates generally to a structural reinforcement for locally reinforcing portions of containers or other articles of manufacture. More particularly, the present invention relates to a structural reinforcement having a bracket associated with a reinforcement material.

BACKGROUND OF THE INVENTION

An article of manufacture is often required to endure various different loads during use of the article. Examples of articles, which are required to endure such loads include, without limitation, furniture, buildings, containers, automotive vehicles and others. Depending on the materials used to form an article, the structural configuration of the article and the like, it may be advantageous to structurally reinforce a portion of the article with a reinforcement. As examples, U.S. Pat. Nos. 5,755,486; 4,901,500; and 4,751,249 describe prior art reinforcing devices. Thus, the present invention provide a structural reinforcement for reinforcing an article of manufacture and a method of using the reinforcement.

SUMMARY OF THE INVENTION

The present invention is directed to a structural reinforcement member and an article structurally reinforced with the member. The article may be chosen from various articles of manufacture, but is preferably a container and more preferably a filing cabinet. Accordingly, the article will typically include a plurality defining a cavity therein. Preferably, the article includes a first wall and a second wall of the plurality of walls wherein the first wall is skew (e.g., substantially perpendicular) to the second wall. The first wall and second wall may be supplied by various articles or members such as a structural frame member of a filing cabinet, a housing of filing cabinet or both may supply such walls. In a preferred embodiment with structural member, a first wall is integrally connected to a second wall via a curved portion of the structural frame member wherein the curved portion has at least one rib. In a more preferred embodiment, a third wall and a fourth wall are supplied by an outer housing of the filing cabinet, the third wall being substantially perpendicular to the fourth, the third and fourth wall corresponding to the first and second wall of the structural member. The reinforcement member will typically include a bracket. The bracket preferably includes a generally planar portion and a first extension extending from a first side of the planar portion and a second extension extending from a second side of the planar portion. The planar portion of the bracket may include at least one throughhole. The first extension and the second extension may each include protrusions frictionally assisting in gripping the frame member. The reinforcement member will also typically include an reinforcement material that is preferably expandable. The reinforcement material preferably has a generally planar configuration coextensive with and parallel to the generally planar portion of the bracket. The reinforcement material preferably expands upon exposure to heat and contacts at least the first and second and preferably the third and fourth walls. Additionally, the reinforcement material preferably cures and hardens after expansion to structurally reinforce the first and second walls and also may reinforce the third and fourth walls. In a highly preferred embodiment, the reinforcement material expands through a through-hole of the bracket to contact and wet at least one of the plurality of walls.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and inventive aspects of the present invention will become more apparent upon reading the following detailed description, claims, and drawings, of which the following is a brief description: [0004]
FIG. 1 illustrates a perspective view of an exemplary embodiment of a structural reinforcement in accordance with an aspect of the present invention; [0005]
FIG. 2 illustrates a front view of the exemplary structural reinforcement of FIG. 1; [0006]
FIG. 3 illustrates a rear view of the exemplary structural reinforcement of FIG. 1; [0007]
FIG. 4 illustrates a top view of the exemplary structural reinforcement of FIG. 1; [0008]
FIG. 5 illustrates a side view of the exemplary structural reinforcement of FIG. 1; and [0009]
FIGS. [0010] 6(a) and 6(b) illustrates side cut-away views of the exemplary structural reinforcement of FIG. 1 applied to a container.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention generally provides a structural reinforcement, a method of use for the reinforcement and a structurally reinforced article. Preferably the reinforcement, the method of use and the reinforced article provide one or a combination of the following: [0011]
(1) a portion of an article of manufacture (e.g., a container), which preferably includes a plurality of walls, and which preferably includes a cavity or corner, which is at least partially defined by the wall; [0012]
(2) a bracket having a generally planar portion and at least one flange, the flange preferably extending away from the generally planar portion at least partially in a direction perpendicular to the planar portion, the flange preferably providing an attachment surface supporting a fastening protrusion, the fastening protrusion preferably assisting in attaching the bracket adjacent the plurality of walls of the portion of the article of manufacture; and [0013]
(3) a reinforcement material connected to the bracket, the reinforcement material preferably being activatible to change states (e.g., expand, flow, soften, harden), the reinforcement material preferably being generally planar and generally parallel with the planar portion of the bracket, the reinforcement material preferably positioned between the at least one wall and the generally planar portion of the bracket upon attachment of the bracket to the at least one wall. [0014]
Referring to FIGS. [0015] 1-5, there is illustrated an exemplary structural reinforcement 10 according to an aspect of the present invention. The reinforcement 10 includes a bracket 12 and a reinforcement material 14. The reinforcement 10 of the present invention may find utility in a variety of articles of manufacture. For example, and without limitation, the reinforcement 10 may be integrated into furniture, appliances, transportation vehicles, buildings or other items, which preferably exhibit structural integrity against one or mores forces during their use. In one preferred embodiment, the reinforcement 10 is utilized to reinforce a portion of a container such as a file cabinet or the like.
The [0016] bracket 12 of the present invention may be formed in a variety of configurations. Preferably, the bracket 12 includes a central portion 18, a pair of flanges 20 and a pair of walls 22. In the embodiment shown, the central portion 18 is substantially planar, and substantially rectangular. In alternative embodiments, it is contemplated that the central portion may be provided in a variety of geometric configurations such as circular, elliptical, square, polygonal or the like. It is additionally contemplated that the central portion may be contoured. For maintaining a lower weight for the bracket, the central portion is preferably skeletal and includes one or more through-holes. As shown, the bracket 12 includes a pair of equally sized substantially square through-holes 24 extending through the central portion 18, however, the bracket 12 may include more or less through-holes and the through-holes may be sized and positioned as desired or needed.
The [0017] flanges 20 extend from opposite sides of the central portion 18 and include a first portion 28 extending away from the central portion 18 in a direction at least partially perpendicular and preferably substantially perpendicular to the central portion 18. Each of the first portions 28 is connected at one end to the central portion 18 and at another end to a second portion 32. As shown, each of the second portions 32 is generally L-shaped and provides a substantially planar surface 36, however, the second portions 32 may be provided in a variety of shapes and configurations and the planar surface 36 may be contoured to correspond to a wall of an article of manufacture. Preferably, as shown, one or more fastening protrusions 40 extend outwardly from the substantially planar surface 36.
The [0018] walls 22 extend in a direction at least partially and preferably substantially perpendicular to the central portion 18. Preferably, the walls 22 are located adjacent to the flanges 20 and extend from the same sides of the central portion 18 as the flanges 20. It is contemplated that the walls 22 may be separate from or integrated with the flanges 20. It is preferable for the walls 22 to generally extend with (e.g., substantially parallel to) the first portions 28 of the flanges 20 although not necessarily required. In the embodiment shown, each of the walls 22 includes a pair of generally arcuate portions 44 although various alternative contours may be included in the walls 22 or the walls 22 may be substantially planar.
The [0019] reinforcement material 14 is attached to the bracket 12 and is preferably attached to the central portion 18 of the bracket 12. In the embodiment shown, the reinforcement material 14 is substantially block-shaped and provides an attachment surface 50 wherein the surface is configured to oppose, contact and attach the reinforcement material to the central portion 18 of the bracket 12. Additionally the reinforcement material 14 includes an optional through-hole 54 extending therethrough. In alternative embodiments, the reinforcement material 14 may be provided in various shapes such as disk-shaped, contoured or the like and various surfaces of the reinforcement material 14 may contact the central portion 18. The reinforcement material 14 is preferably located or positioned between the walls 22, the flanges 20 or both. As shown, the reinforcement material 14 includes concavities 58 for matingly receiving the arcuate portions 44 of the walls 22 of the bracket 12 for assisting in securing the reinforcement material 14 to the bracket 12.
Preferably, the [0020] reinforcement material 14 is a high compressive strength heat activated reinforcement material having foamable characteristics. The material may be generally dry to the touch or tacky, may have magnetic attributes, and can be placed intermediate the flanges 20 in any form or desired pattern, placement, or thickness, which may be uniform or non-uniform. In one preferred embodiment, the reinforcement material 14 is between about 1 mm and about 10 mm thick. One exemplary expandable material is L-5204 structural foam available through L&L Products, Inc. of Romeo, Mich.
Though other heat activated materials are possible for the [0021] reinforcement material 14, a preferred heat activated material is an expandable plastic, and preferably one that is foamable. A particularly preferred material is an epoxy-based structural foam. For example, without limitation, the structural foam may be an epoxy-based material, including an ethylene copolymer or terpolymer that may possess an alpha-olefin. As a copolymer or terpolymer, the polymer is composed of two or three different monomers, i.e., small molecules with high chemical reactivity that are capable of linking up with similar molecules.
A number of epoxy-based structural reinforcing foams are known in the art and may also be used to produce the structural foam. A typical structural foam includes a polymeric base material, such as an epoxy resin or ethylene-based polymer which, when compounded with appropriate ingredients (typically a blowing and curing agent), expands and cures in a reliable and predicable manner upon the application of heat or the occurrence of a particular ambient condition. From a chemical standpoint for a thermally-activated material, the structural foam is usually initially processed as a flowable thermoplastic material before curing. It will crosslink upon curing, which makes the material incapable of further flow. [0022]
Examples of preferred structural foam formulations that are epoxy-based materials are commercially available from L&L Products of Romeo, Mich., under the designations L5206, L5207, L5208, L5209, L5020, L5222, L5214, L4200, L4200, L4100, L8000, L5001, XP321 and XP721. One advantage of the preferred structural foam materials over prior art materials is that the preferred materials can be processed in several ways. The preferred materials can be processed by injection molding, extrusion compression molding or with a mini-applicator. This enables the formation and creation of part designs that exceed the capability of most prior art materials. In one preferred embodiment, the structural foam (in its uncured state) generally is dry or relatively free of tack to the touch and can easily be attached to the [0023] central portion 18 through fastening means which are well known in the art.
While the preferred materials for fabricating the [0024] reinforcement material 14 have been disclosed, the reinforcement material 14 can be formed of other materials provided that the material selected is heat-activated or otherwise activated by an ambient condition (e.g. moisture, pressure, time or the like) and cures in a predictable and reliable manner under appropriate conditions for the selected application. One such material is the epoxy based resin disclosed in U.S. Pat. No. 6,131,897, the teachings of which are incorporated herein by reference, filed with the United States Patent and Trademark Office on Mar. 8, 1999 by the assignee of this application. Some other possible materials include, but are not limited to, polyolefin materials, copolymers and terpolymers with at least one monomer type an alpha-olefin, phenol/formaldehyde materials, phenoxy materials, and polyurethane materials with high glass transition temperatures. See also, U.S. Pat. Nos. 5,766,719; 5,755,486; 5,575,526; and 5,932,680, (incorporated by reference). In general, the desired characteristics of the structural foam include relatively high stiffness, high strength, high glass transition temperature (typically greater than 70 degrees Celsius), and good corrosion resistance properties. In this manner, the material does not generally interfere with the materials systems employed by manufacturers such as furniture manufacturers, automobile manufacturers and others.
In applications where the [0025] reinforcement material 14 is a heat activated, thermally expanding material, an important consideration involved with the selection and formulation of the material comprising the structural foam is the temperature at which a material reaction or expansion, and possibly curing, will take place. For instance, in most applications, it is undesirable for the material to be reactive at room temperature or otherwise at the ambient temperature in a production environment. More typically, the structural foam becomes reactive at higher processing temperatures, such as those encountered in an assembly plant or such as those, which might be induced upon the foam. Exemplary activation temperatures may range from about 140° C. to about 204.44° C. (about 290° F. to 400° F.) (e.g. temperatures experienced in a paint or priming oven. If needed, blowing agents and blowing agent activators can be incorporated into the composition to cause expansion at different temperatures outside the above ranges.
Generally, suitable expandable foams have a range of expansion ranging from approximately 0 to over 1000 percent. The level of expansion of the structural foam may be increased to as high as 1500 percent or more. Typically, strength is obtained from products that possess low expansion. Preferably, the expansion level is in the range of about 0% to about 400%, more preferably about 30% to about 200 % and most preferably about 50% to about 100% [0026]
Some other possible materials include, but are not limited to, polyolefin materials, copolymers and terpolymers with at least one monomer type an alpha-olefin, phenol/formaldehyde materials, phenoxy materials, and polyurethane. See also, U.S. Pat. Nos. 5,266,133; 5,766,719; 5,755,486; 5,575,526; 5,932,680; and WO 00/27920 (PCT/US 99/24795) (all of which are expressly incorporated by reference). [0027]
In another embodiment, the [0028] reinforcement material 14 is provided in an encapsulated or partially encapsulated form, which may comprise a pellet, which includes an expandable foamable material, encapsulated or partially encapsulated in an adhesive shell. An example of one such system is disclosed in commonly owned, co-pending U.S. application Ser. No. 09/524,298 (“Expandable Pre-Formed Plug”), hereby incorporated by reference.
In addition, as discussed previously, preformed patterns may also be employed such as those made by extruding a sheet (having a flat or contoured surface) and then die cutting it according to a predetermined configuration in accordance with the chosen article of manufacture, and applying it thereto. The reinforcement material may include up to 60% filler materials. Moreover, the reinforcement material may include strength additives such as glass, carbon, or aramid fibers, and may include viscosity controllers, thickeners (e.g. silica) or the like. [0029]
The skilled artisan will appreciate that the system may be employed in combination with or as a component of a conventional sound blocking baffle, or a vehicle structural reinforcement system, such as is disclosed in commonly owned co-pending U.S. application Ser. Nos. 09/524,961 or 09/502,686 (hereby incorporated by reference). [0030]
Assembly [0031]
In a particular preferred embodiment, the bracket could be formed of injection molded nylon, injection molded polymer, or molded metal (such as high strength to weight aluminum, magnesium, steel and titanium, an alloy derived from the metals, and even a metallic foam). The materials may be reinforced with fibers (e.g. glass fibers). In other alternatives, the bracket may be shaped sheet metal or low carbon rolled steel (e.g., 1008 or 1010 twin rolled steel). It is additionally contemplated that the bracket may be coated or heat treated and may include members of fasteners for assisting the attachment of the reinforcement material. [0032]
For forming the [0033] reinforcement 10, the reinforcement material 14 may be applied to the bracket 12 using a variety of techniques or protocols. For example, and without limitation, the reinforcement material may be applied to the bracket 12 by spraying, brushing, hand applying, swabbing, taping, pumping from reservoir, extrusion coating, die cutting, injection molding (e.g., overmolding, two-shot molding or the like), mechanically fastening, heat bonding or the like. In highly preferred embodiments, the reinforcement material 14 is applied to the bracket 12 in a viscoelastic state (i.e., at a temperature that softens the material 14 without activating it). Such a viscoelastic state may be achieved by injection molding the material 14, extruding the material 14 and the like. In one embodiment, the bracket 12 is placed at least partially in a mold followed by injection molding the material 14 into the mold in the viscoelastic state such that the material adheres to the bracket 12 upon cooling. In another embodiment, an extruder such as the mini-applicator described above extrudes the material directly onto the bracket 12 in the viscoelastic state. For extrusion techniques, it may be necessary to further cut or shape the bracket 12, the material 14 or both after application.
Operation [0034]
For application of the [0035] reinforcement 10 to an article of manufacture, the reinforcement 10 may be initially attached to the article of manufacture using a variety of techniques. For example, and without limitation, the reinforcement 10 may be mechanically fastened to an article with fasteners such as a strap, a push pin, a rivet, a heat stake, welding an interference fit of the like or the reinforcement 10 may be adhered to the article. Alternatively, a variety of art-known techniques may be used to initially attach the reinforcement to the article. Additionally, the reinforcement 10 may be attached to nearly any portion of an article of manufacture that needs reinforcing or to a portion of the article adjacent a portion that needs reinforcement. For instance, the reinforcement 10 may be attached at or near corners, edges, relatively weak portions, side walls, load bearing seams, stress points or the like for reinforcement thereof.
In one embodiment, the present invention contemplates that the [0036] reinforcement 10 will be used to reinforce a first wall and a second wall that cooperatively form a corner or edge of a container and which are skew with respect to one another. More particularly, the present invention contemplates that the reinforcement 10 will be used to reinforce a first wall, a second wall and optionally a third wall wherein each of the walls are substantially perpendicular to each other and form a corner of a cabinet.
According to one preferred embodiment, and referring to FIG. 6([0037] a), the reinforcement 10 is attached adjacent to one or more of a plurality of walls 80 that form a metal housing of a cabinet 84. Preferably, at least two and possibly three (e.g., two side walls and a bottom wall) of the plurality of walls 80 are substantially perpendicular to each other and form a corner or edge 82 of the cabinet 84 (e.g., a storage or file cabinet). In the embodiment shown, the cabinet 84 includes a structural frame member 88 (preferably metal) for supporting drawers or otherwise (not shown) within the cabinet 84. The structural frame member 88 also provides a plurality of walls 92 (e.g., a pair a wall perpendicular to each other). Preferably, the walls 92 are connected by a curved edge or corner portion 94 of the member 88 and the curved portion 94 may include one or more ribs 96 for structural integrity. It is also preferable for at least two of the walls 92 of the structural member 88 to correspond to the walls 80 of the housing of the cabinet 84.
It is contemplated that the [0038] reinforcement 10 may be positioned in a variety of positions or locations and may be secured in a variety of manners. As shown, the plurality of walls 80 of the cabinet 84 and the walls 92 of the frame member 88 cooperatively or alone define a cavity 106 within the cabinet 84. In this preferred embodiment, the reinforcement 10 is positioned within the cavity 106 between the various walls 80, 92 by interferingly engaging the flanges 20 of the bracket 12 with flanges 100 of the structural member 88 such that the fastening the flanges 20, the protrusions 40 or both frictionally engage or protrude into the material (e.g., the metal) of the flanges 100. As shown, the central portion 18 and reinforcement material 14 are generally parallel to at least one of the walls 80. Preferably, the reinforcement material 14 is positioned between at least one of the walls 80 and the central portion 18 of the bracket 12.
After initial attachment, the [0039] reinforcement material 14 is activated to expand and then cure and harden as shown in FIG. 6(b). During expansion of this preferred embodiment, the reinforcement material 14 wets the walls 80, 92 to form a bond with the walls 80, 92 upon curing. During such expansion, the reinforcement material 14 preferably expands through the through-holes 24 of the brackets to contact and wet at least one of the walls 80, 92. Upon curing, the reinforcement material 14, either in conjunction with or on its own, imparts stiffness, rigidity and reinforcement to the walls 80, 92 the corner 82 or both.
Advantageously, the [0040] reinforcement 10 structurally reinforces the walls. Such reinforcement can be quite advantageous for walls of cabinets or other containers where one of the walls such as a bottom wall is contacted by the floor or other objects, which may place force on the walls. More specifically, during transportation, placement, positioning and the like of containers or cabinets (e.g., particularly for cabinets having objects inside), various forces from a floor or from other objects may be exerted upon the walls, and the reinforcement 10 can guard against deformation of the walls.
The preferred embodiment of the present invention has been disclosed. A person of ordinary skill in the art would realize however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention. [0041]

Claims

What is claimed is:

1. A structurally reinforced article, comprising:

a plurality of walls of a container, a first wall of the plurality of walls being skew relative to a second wall of the container for forming a corner;

a bracket capable of securing itself adjacent said corner; and

a reinforcement material attached to the bracket, the reinforcement material expanding and curing to form an intimate bond with and to reinforce the first wall and the second wall.

2. A structurally reinforced article as in claim 1 wherein the container is a filing cabinet.

3. A structurally reinforced article as in claim 2 wherein the first wall and second wall are part of a housing of the filing cabinet.

4. A structurally reinforced article as in claim 2 wherein the first wall and second wall are part of a structural frame member of the filing cabinet.

5. A structurally reinforced article as in claim 2 wherein the plurality of walls are part of a structural frame member of the filing cabinet and part of a housing of the filing cabinet.

6. A structurally reinforced article as in claim 1 wherein the bracket includes a generally planar portion having at least one through-hole extending therethrough.

7. A structurally reinforced article as in claim 6 wherein the reinforcement material expands through the at least one through-hole of the bracket to contact and wet at least one of the plurality of walls.

8. A structurally reinforced article as in claim 1 wherein the bracket includes an extension with a protrusion for assisting in attaching the bracket adjacent the plurality of walls.

9. A structurally reinforced article, comprising:

a plurality of walls of a filing cabinet, a first wall of the plurality of walls substantially perpendicular to a second wall of the plurality of walls, the first and second walls at least partially defining a cavity therein;

a bracket having a generally planar portion and a first extension extending from a first side of the planar portion and a second extension extending from a second side of the planar portion; and

an expandable reinforcement material having a generally planar configuration, the expandable material being substantially coextensive with and parallel to the generally planar portion of the bracket, the expandable material expanding and curing to form an intimate bond with and to reinforce the first wall and the second wall.

10. A structurally reinforced article as in claim 9 wherein the plurality of walls are part of a housing of the filing cabinet.

11. A structurally reinforced article as in claim 9 wherein the first wall and second wall are part of a structural frame member of the filing cabinet.

12. A structurally reinforced article as in claim 9 wherein the first wall and second wall are part of a structural frame member of the filing cabinet and part of a housing of the filing cabinet.

13. A structurally reinforced article as in claim 9 wherein at least one through-hole extends through the generally planar portion of the bracket.

14. A structurally reinforced article as in claim 13 wherein the reinforcement material expands through the at least one through-hole of the bracket to contact and wet at least one of the plurality of walls.

15. A structurally reinforced article as in claim 9 wherein the extensions of the bracket each include a protrusion for assisting in attaching the bracket adjacent the plurality of walls.

16. A structurally reinforced article, comprising:

a plurality of walls of a filing cabinet, the plurality of walls defining a cavity therein wherein:

i) a first wall and a second wall of the plurality of walls are supplied by a structural frame member of the filing cabinet, the first wall being substantially perpendicular to the second wall;

ii) the first wall is integrally connected to the second wall via a curved portion of the structural frame member, the curved portion having at least one rib; and

iii) a third wall and a fourth wall of the of the plurality of walls are supplied by an outer housing of the filing cabinet, the third wall being substantially perpendicular to the fourth, the third and fourth wall corresponding to the first and second wall;

a bracket having a generally planar portion and a first extension extending from a first side of the planar portion and a second extension extending from a second side of the planar portion wherein:

i) the planar portion includes at least one through-hole; and

ii) the first extension and the second extension each include protrusions frictionally assisting in gripping the frame member; and

an expandable reinforcement material having a generally planar configuration, the expandable material being generally coextensive with and parallel to the generally planar portion of the bracket wherein:

i) the expandable material expands upon exposure to heat and contacts the first, second, third and fourth walls; and

ii) the expandable material cures and hardens after expansion to structurally reinforce the first, second, third and fourth walls.

17. A structurally reinforced article as in claim 13 wherein the reinforcement material expands through the through-hole of the bracket to contact and wet at least one of the plurality of walls.