FIELD OF THE INVENTION
The present invention relates to a system and method for joining structural and mechanical parts made from dissimilar materials.
BACKGROUND OF THE INVENTION
Two main issues with joining dissimilar materials are material compatibility and applicability of the joining process. More particularly, there are issues involved with joining aluminum to magnesium, to steel or to composites with known joining processes, such as fusion welding (e.g., gas metal arc welding) and solid-state welding (e.g., friction stir welding). These include metallurgical incompatibility, which results in uncontrolled cracking in welds and/or formation of brittle intermetallics; drastic differences in electromotive potential, which may lead to severe galvanic corrosion in the presence of salts and/or moisture; and incompatibility in the coefficient of thermal expansion, which could cause formation of intense residual stresses at joints and lead to failure under certain loading conditions, such as stress corrosion. What is needed is an appropriate system and method for proper joining of structural and mechanical parts made from dissimilar materials (e.g., metals and metal composites) to allow, among other things, the proper transmission of loads between them.
SUMMARY OF THE INVENTION
A structural assembly that includes a first structural member made from a first material, a second structural member made from a second material and adapted to mate and interlock with the first structural member, and a third structural member made from the first material to facilitate the permanent affixation between the first and second structural members. More particularly, the first structural member includes a post made from a first material, such as aluminum, the second structural member includes a tube made from a second material, such as magnesium, and is sized and shaped to fit within the post, and an insert made from the first material (e.g., aluminum) that is sized and shaped to fit within the tube. The post includes at least one aperture encircled by an inwardly extending protrusion, and the tube includes at least one aperture that is sized and shaped to mate and interlock with the protrusion when the post and tube are mated and interlocked with one another. When the post, tube and insert are mated and interlocked with one another, a snug fit is formed between the post and the tube and between the tube and the insert. In such configuration, an outer surface of the insert is exposed through the aperture of the post and the aperture of the tube. The aperture of the tube is substantially encased or shielded by the protrusion of the post such that there are no exposed surfaces of the tube in the area of the aperture of the post and the outer surface of the insert. Consequently, the aluminum post may be welded to the aluminum insert, thereby permanently affixing, for example, the aluminum post and the magnesium tube to one another without metallurgical altering or local welding of the magnesium tube.
Further features and advantages of the invention will appear more clearly on a reading of the detailed description of the embodiments of the invention, which is given below by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference is made to the following detailed description of the embodiments considered in conjunction with the accompanying drawings, in which:
FIG. 1 is an exploded top perspective view of a post and tube joint assembly in accordance with an embodiment of the present invention;
FIG. 2A is an exploded top plan view of the post and tube joint assembly illustrated in FIG. 1;
FIG. 2B is an exploded side elevational view of the post and tube joint assembly illustrated in FIG. 1;
FIG. 3A is a top perspective view of the post and tube joint assembly illustrated in FIG. 1, showing an intermediate step of the components thereof being interlocked with one another;
FIG. 3B is a top perspective, cross-sectional view of the post and tube joint assembly illustrated in FIG. 3A;
FIG. 3C is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 3A;
FIG. 4A is a top perspective cross-sectional view of the post and tube joint assembly illustrated in FIG. 1, showing the components thereof interlocked with one another;
FIG. 4B is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 4A;
FIG. 4C is an enlarged cross-sectional view showing detail 4B from FIG. 4B;
FIG. 5A is a top perspective view of the post and tube joint assembly illustrated in FIG. 4A, showing the components thereof welded to one another;
FIG. 5B is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 5A;
FIG. 5C is an enlarged cross-sectional view showing detail 5B from FIG. 5B;
FIG. 6A is an exploded top perspective view of a post and tube joint assembly in accordance with a another embodiment of the present invention;
FIG. 6B is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 6A, showing an intermediate step of the components thereof being interlocked with one another;
FIG. 6C is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 6A, showing the components thereof interlocked with one another;
FIG. 6D is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 6C, showing the components thereof welded to one another;
FIG. 7A is an exploded top perspective view of a post and tube joint assembly in accordance with yet another embodiment of the present invention;
FIG. 7B is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 7A, showing an intermediate step of the components thereof being interlocked with one another;
FIG. 7C is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 7A, showing the components thereof interlocked with one another;
FIG. 7D is a side cross-sectional view of the post and tube joint assembly illustrated in FIG. 7C, showing the components thereof welded to one another;
FIG. 8A is an exploded top perspective view of a post and tube joint assembly in accordance with another embodiment of the present invention;
FIG. 8B is a cross-sectional view of an insert employed by the post and tube joint assembly illustrated in FIG. 8A;
FIG. 8C is perspective view of another embodiment of an insert employed by the post and tube joint assembly illustrated in FIG. 8A;
FIG. 8D is an exploded top perspective view of the post and tube joint assembly illustrated in FIG. 8A, showing an adhesive applied to the components thereof;
FIG. 8E is a top perspective view of the post and tube joint assembly illustrated in FIG. 8A, showing the components thereof interlocked with and welded to one another; and
FIGS. 9 through 12 show a flat sheet assembly in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring to FIGS. 1 through 2B, a post and tube joint assembly 10 includes a hollow, rectangular-shaped post 12, a hollow, rectangular-shaped tube 14, and a hollow, rectangular-shaped insert 16. While the post 12, the tube 14 and the insert 16 are each rectangular in shape, they can consist of different shapes and sizes (e.g., cylindrical, triangular, hexagonal, etc.) to suit the purposes of the varied configurations to be appreciated from the teachings herein. In addition, the post 12 and the insert 16 may be manufactured from the same material, while the tube 14 is manufactured from a different material. The post 12 and the insert 16, as well as the tube 14, may be made from many types of metals suitable for the characteristics contemplated from the teachings herein. For example, the post 12 and the insert 16 may be made from aluminum, and, more particularly, T6 temper 6061 aluminum alloy, while the tube 14 may be made from steel, an aluminum alloy composite, or magnesium. The tube 14 may also be made from other materials, such as an organic based composite (e.g., carbon fibers bonded together) an inorganic based composite (e.g., metallic fibers braded and adhesively bonded), or similar composites.
With continued reference to FIGS. 1 through 2B, the post 12 includes a first end 18 and a second end 20 opposite thereof, a first pair of opposed walls 22, 24 and a second pair of opposed walls 26, 28, which form a rectangular-shaped cavity 30. The cavity 30 is sized and shaped to slidably receive the tube 14 and the insert 16, which shall be described in further detail below. The wall 22 includes a first pair of circular-shaped apertures 32, 34, while the wall 24 includes a second pair of circular-shaped apertures 36, 38 (not shown in FIGS. 1 through 2B, but see FIGS. 3B and 3C). Each of the apertures 32, 34 includes a circular-shaped “tea-cup” protrusion 40, 42, respectively, that extends into the cavity 30 from the wall 22, while each of the apertures 36, 38 includes a circular-shaped “tea-cup” protrusion 44, 46, respectively, that extends into the cavity 30 from the wall 24 (not shown in FIGS. 1 through 2B, but see FIGS. 3B and 3C). The aperture 32 and the aperture 36 are aligned with one another, but they need not be. Similarly, the aperture 34 and the aperture 38 are aligned with one another, but they need not be. While the post 12 includes the apertures 32, 34 and the apertures 36, 38 (for a total of four apertures), it may include more or less than four apertures. While each of the apertures 32, 34 and the apertures 36, 38 are each circular in shape, and each of the protrusions 40, 42 and the protrusions 44, 46 are circular in shape, they may consist of other shapes and sizes to suit the purposes of the varied configurations to be appreciated from the teachings herein. The apertures 32, 34, the apertures 36, 38, the protrusions 40, 42, and the protrusions 44, 46 may be formed from any means known in the art, such as, for example, machining, punch forming into dies (i.e., “tea cupping”), cast or forged.
Still referring to FIGS. 1 through 2B, the tube 14 includes a first end 48 and a second end 50 opposite thereof, a pair of opposed walls 52, 54 and a pair of opposed walls 56, 58, which form a rectangular-shaped cavity 60. The cavity 60 is sized and shaped to slidably receive the insert 16, which shall be described in further detail below. The wall 52 includes a pair of circular-shaped apertures 62, 64, while the wall 54 includes a pair of circular-shaped apertures 66, 68 (not shown in FIGS. 1 through 2B, but see FIGS. 3B and 3C). The aperture 62 and the aperture 66 are aligned with one another, but they need not be. The aperture 64 and the aperture 68 are aligned with one another, but they need not be. While the apertures 62, 64 and the apertures 66, 68 are each circular in shape, they may consist of other shapes and sizes to suit the purposes of the varied configurations to be appreciated from the teachings herein. A slot 70 is formed within the wall 52 proximate to a corner 71 where the wall 52 and the wall 56 intersect, while a slot 72 is formed with the wall 52 proximate to a corner 73 where the wall 52 and the wall 58 intersect. Similarly, a slot 74 is formed within the wall 54 proximate to a corner 75 where the wall 54 and the wall 56 intersect, while a slot 76 is formed with the wall 54 proximate to a corner 77 where the wall 54 and the wall 58 intersect. Each of the slots 70, 72 and the slots 74, 76 have lengths that extend from the end 48 of the tube 14 to a point P1 intermediate the ends 48, 50 of the tube 14. The length of the slots 70, 72 and the length of the slots 74, 76 are the same, but the lengths can be different. The functions of the slots 70, 72 and the slots 74, 76 shall be described below.
Still referring to FIGS. 1 through 2B, the insert 16 includes a first end 78 and a second end 80 opposite thereof, a first pair of opposed walls 82, 84 and a second pair of opposed walls 86, 88, which form a rectangular-shaped cavity 90. A slot 92 is formed within the wall 82 proximate to a corner 93 where the wall 82 and the wall 86 intersect, while a slot 94 is formed within the wall 82 proximate to a corner 95 where the wall 82 and the wall 88 intersect. Similarly, a slot 96 is formed within the wall 84 proximate to a corner 97 where the wall 84 and the wall 86 intersect, while a slot 98 is formed within the wall 84 proximate to a corner 99 where the wall 84 and the wall 88 intersect. Each of the slots 92, 94 and the slots 96, 98 has a length that extends from the end 78 of the insert 16 to a point P2 intermediate the ends 78, 80 of the insert 16. The length of the slots 92, 94 and the length of the slots 96, 98 are the same, but the lengths can be different. The insert 16 includes a first retainment tab 100 that extends outwardly from the wall 82 at the end 78 of the insert 16, while a second retainment tab 102 extends outwardly from the wall 84 at the end 78 of the insert 16. Each of the tabs 100, 102 has a length that is substantially the width of the walls 82, 84, respectively. The tab 100 includes a curved outer surface 101, while the tab 102 includes a curved outer surface 103 (see FIG. 2B). The functions of the slots, 92, 94, the slots 96, 98, and the retainment tabs 100, 102 shall be described below.
FIGS. 3A through 3C show an intermediate step of assembling the post 12, the tube 14 and the insert 16 with one another. More particularly, the end 80 of the insert 16 is inserted into the cavity 60 of the tube 14 at the end 48 thereof. In such position, the retainment tabs 100, 102 of the insert 16 abut against the end 48 of the tube 14, which inhibit the insert 16 from sliding out the end 50 of the tube 14 during assembly. The cavity 60 of the tube 14 is sized and shaped to accommodate the receipt of the insert 16 and firmly retain the insert 16 therein.
Next, the tube 14 and the insert 16 assembly as described above are slidably inserted into the cavity 30 of the post 12 at an end 20 thereof. The cavity 30 of the post 12 is sized and shaped such that the tube 14 and the insert 16 elastically deflect inwardly when the tube 14 and the insert 16 are inserted into the post 12 (see FIGS. 3B and 3C). More particularly, as the tube 14 and the insert 16 assembly are inserted into the post 12, the tab 100 of the insert 16 reaches the protrusion 42 of the post 12 and the tab 102 reaches the protrusion 46 of the post 12. At this point, the curved surfaces 101, 103 of the tabs 100, 102 and the “tea-cup” shapes of the protrusions 42, 46 enable the tabs 100, 102 to travel over (i.e., ramp over) the protrusions 42, 46, respectively. As the tabs 100, 102 travel over the protrusions 42, 46, resulting forces act against the tabs 100, 102 and, in turn, against the first end 48 of the tube 14. As a result of such forces, the walls 52, 54 of the tube 14 deflect inwardly, while the walls 82, 84 of the insert 16 deflect inwardly. The slots 70, 72 of the tube 14 facilitate the deflection of the wall 52 of the tube 14 inwardly, while the slots 74, 76 of the tube 14 facilitate the deflection of the wall 54 of the tube 14 inwardly. Similarly, the slots 92, 94 of the insert 16 facilitate the deflection of the wall 82 of the insert 16 inwardly, while the slots 96, 98 of the insert 16 facilitate the deflection of the wall 84 of the insert 16 inwardly. As indicated above, the lengths of the slots 70, 72 and the slots 74, 76 of the tube 14 are equal in order to facilitate uniform deflection of the walls 52, 54 of the tube 14. Similarly, the lengths of the slots 92, 94 and the slots 96, 98 of the insert 16 are equal in order to facilitate uniform deflection of the walls 82, 84 of the insert. However, the aforesaid lengths can be adjusted (e.g., shortened or lengthened) to suit the purposes of the varied configurations to be appreciated from the teachings herein.
It is also noted that the apertures 32, 34 of the post 12 are not aligned with one another along axis A-A, as shown in FIGS. 2A and 3A, and that the apertures 36, 38 of the post 12 are not aligned with one another along axis A-A. This configuration prevents the aperture 62 from mating with the protrusion 40 and the aperture 66 from mating with the protrusion 44. As a result, the tube 14 and the insert 16 assembly are prevented from interlocking with the post 12 prematurely.
As the tube 14 and the insert 16 assembly continues to be inserted within the post 12, the protrusions 42, 46 act against the wall 52 of the tube 14 to maintain the deflection of the tube 14 and the insert 16 as discussed above. Once again, the curved surfaces 101, 103 of the tabs 100, 102 and the “tea-cup” shapes of the protrusions 42, 46 enable the tabs 100, 102 to slide over the protrusions 44, 48, respectively.
FIGS. 4A through 4C show the tube 14 and the insert 16 assembly fully inserted within the post 12 and snapped into place. More particularly, the apertures 62, 64 of the tube 14 engage and cooperate with the protrusions 40, 42 of the post 12, respectively, while the apertures 66, 68 of the tube 14 engage and cooperate with the protrusions 44, 46 of the post, respectively. In such manner, the walls 52, 54 of the tube 14 and the walls 82, 84 of the insert 16 spring back into their substantially same original position (i.e., before deflection) and are locked into place within the post 12. As a result, the protrusions 40, 42, are aligned and interlocked with the apertures 62, 64, respectively, while the protrusions 44, 46 are aligned and interlocked with the apertures 66, 68, respectively. The thickness of the walls 52, 54 of the tube 14 is sized appropriately to enable the protrusions 40, 42, 44, 46 to sufficiently mate and interlock with the respective apertures 62, 64, 66, 68. It is also noted that the tube 14 and the insert 16 are designed and manufactured such that their elastic deformation is within the range of approximately 99-100% (e.g., no plastic deformation at >0.2 yield strengths); and, therefore, such components can carry out the mechanical interlocking process described herein.
FIGS. 5A through 5C show the welding of the post 12 to the insert 16, which are made from the same material (e.g., aluminum). More particularly, welds 104 are placed within each of the apertures 32, 34 of the post 12 and the apertures 62, 64 of the tube 14, resulting in welded joints between the protrusions 40, 42 and the wall 82 of the insert 16. Similarly, welds 106 are placed within the apertures 36, 38 of the post 12 and the apertures 66, 68 of the tube 14, resulting in welded joints between the protrusions 44, 46 and the wall 84 the insert 16. Since the post 12 and the insert 16, which are made from the same material (e.g., aluminum), are permanently welded to one another by the welds 104, 106, the tube 14, which is made from a different material (e.g., magnesium) is permanently retained within the post 12. Consequently, the mechanical interlock between the post 12 and the tube 14 described above is permanently affixed.
The welds 102, 104 may be made from any welding process known in the art, such as fusion-based (e.g., GMAW, GTAW, LBW, LSBW, etc.) or solid-state based (e.g., FSW, FW Plunge, etc.). Alternatively, the welds 102, 104 need not be included, and the welding process described above could be substituted with any other joining and fixation processes known in the art, such as rivets, bolts, screws, etc. that enable the post 12 and tube 14 to be secured together in a manner that ensures the mechanical interlocks between them do not separate.
The mechanical interlocking features of the post and joint assembly 10 enable load transmission through the post 12 and the tube 14, while simultaneously keeping the subsequent joining operations localized and confined to joining the post 12 and the insert 16 (which are made of the same material) and separate from the tube 14.
Another embodiment of the present invention is illustrated in FIGS. 6A through 6D. The embodiment shown in FIGS. 6A through 6D includes the same features and is assembled in the same manner as the embodiment shown in FIGS. 1 through 5C, with the exception that the post 12 has two pairs of circular-shaped apertures 32, 34 on the wall 22 thereof and two pairs of circular-shaped apertures 36, 38 on the wall 24 thereof, while the tube 14 has two pairs of circular-shaped apertures 62, 64 on the wall 52 thereof and two pairs of circular-shaped apertures 66, 68 on the wall 54 thereof. In the same manner as the embodiment shown in FIGS. 1 through 5C, the insert 16 is slidably inserted into the tube 14, and the tube 14 and the insert 16 assembly is slidably inserted into the post 16 and locked into place (see FIGS. 6B and 6C). Afterwards, the mechanical interlock between the post 12 and the tube 14 are permanently affixed by welding the post 12 to the insert 16 by welds 104 through each of the apertures 32, 34 of the post 12 and the apertures 62, 64 of the tube 14 and welds 106 through each of the apertures 36, 38 of the post 12 and the apertures 62, 64 of the tube 14.
Another embodiment of the present invention is illustrated in FIGS. 7A through 7D. The embodiment shown in FIGS. 7A through 7D includes the same features and is assembled in the same manner as the embodiment shown in FIGS. 1 through 5C, with the exception that the post 12 has two pairs of oblong-shaped slots 32, 34 on the wall 22 thereof and two pairs of oblong-shaped slots 36, 38 on the wall 24 thereof, while the tube 14 has two pairs of oblong-shaped slots 62, 64 on the wall 52 thereof and two pairs of oblong-shaped slots 66, 68 on the wall 54 thereof. In the same manner as the embodiment shown in FIGS. 1 through 5C, the insert 16 is slidably inserted into the tube 14, and the tube 14 and the insert 16 assembly is slidably inserted into the post 16 and locked into place (see FIGS. 7B and 7C). Afterwards, the mechanical interlock between the post 12 and the tube 14 are permanently affixed by welding the post 12 to the insert 16 by welds 104 through each of the slots 32, 34 of the post 12 and the slots 62, 64 of the tube 14 and by welds 106 through each of the slots 36, 38 of the post 12 and the slots 66, 68 of the tube 14.
Another embodiment of the present invention is illustrated in FIGS. 8A through 8D. Elements illustrated in FIGS. 8A through 8D that correspond to the elements described above with reference to FIGS. 1 though 5C have been designated by corresponding reference numerals increased by two hundred (200). The embodiment of FIGS. 8A through 8D operates in the same manner as the embodiment of FIGS. 1 through 5C, unless it is otherwise stated.
FIGS. 8A through 8D show a post and tube joint assembly 210 that includes a hollow, rectangular-shaped post 212, a hollow, rectangular-shaped tube 214, and a hollow, rectangular-shaped insert 216. These components include the same features as those corresponding to the embodiment shown in FIGS. 1 though 5C described above, with the exception that the tube 214 includes rectangular-shaped channels 201 formed within and extending transversely across an outer surface of a wall 252 and an outer surface of a wall 254 (not shown in the Figures), and T-shaped channels 203 formed within an outer surface of a wall 258 and an outer surface of a wall 256 (not shown in the Figures). In addition, the insert 216 includes oblong-shaped channels 205 formed within an outer surface of a wall 288 and an outer surface of a wall 286 (not shown in the Figures). FIGS. 8B and 8C show additional embodiments of the insert 216, which include channels 207 and 209, respectively, that consist of different shapes and sizes. Accordingly, the channels 201, 203, 205 can consist of a variety shapes and sizes and in any number other than those shown in the Figures. Each of the channels 201, 203 of the tube 214 and the channels 205 of the insert 214 are adapted to receive a sealant and/or an adhesive 211, which provides additional bonding when the post 212, the tube 214 and the insert 216 are interlocked with and welded to one another (see FIG. 8D). In addition, when the post 212 and the tube 214 are interlocked, a sealant and/or adhesive 211 may be applied between the post 212 and the tube 214 around the perimeter of an end 220 of the post 212, as shown in FIG. 8E. The sealant/adhesive 211 is used to improve the overall performance and strength (e.g., mechanical strength, corrosion resistance, etc.) of the assembly 210, as well as to seal area A between the post 212 and the tube 214 to prevent the intrusion of foreign elements (see FIG. 8E). The adhesive/sealant 211 may be applied by injection or manually brushed on. Alternatively, the use of heat-activated or non-heat activated adhesives and/or sealing tapes can be utilized. The adhesive or sealant 211 may be applied prior to or after the mechanical interlocking of the assembly 210, as appropriate.
FIGS. 9 through 14 show a similar system and method with respect to a flat sheet assembly 310. More particularly, FIG. 9 shows the assembly 310 prior to lock-joining the components thereof, which include a first rectangular-shaped sheet 312, a second rectangular-shaped sheet 314, and a third rectangular-shaped sheet 316 that is sandwiched between the first and second sheets 312, 314. While the sheets 312, 314, 316 are each rectangular in shape, they can consist of different shapes and sizes (e.g., square, triangular, circular, oblong, etc.) to suit the purposes of the varied configurations to be appreciated from the teachings herein. In addition, the sheets 312, 314 are each manufactured from the same material, such as aluminum, while the sheet 316 is manufactured from a different material, such as magnesium. Alternatively, the sheets 312, 314, as well as the sheet 316, may be made from other types of metals suitable for the characteristics contemplated from the teachings herein. For example, the sheets 312, 314 may be made from aluminum, while the sheet 316 may be made from steel or an aluminum based composite. The sheet 316 may also be made from other materials, such as an organic based composite (e.g., carbon fibers bonded together) an inorganic based composite (e.g., metallic fibers braded and adhesively bonded), or similar composites.
Referring to FIGS. 9 and 10, the sheet 312 includes a pair of circular-shaped apertures 318, 320 encircled by “tea-cup” shaped protrusions 322, 324 that outwardly extend from a surface 326 of the sheet 312. Referring only to FIG. 9, the sheet 316 includes two circular-shaped apertures 328, 330 that are sized and shaped to receive the protrusions 322, 324 of the sheet 312. As shown in FIG. 11, an adhesive 332 may be applied to a surface 334 of the sheet 312 and a surface 336 of the sheet 314. FIG. 12 shows the assembly of the sheets 312, 314, 316, whereby the protrusions 322, 324 of the sheet 312 are received by the apertures 328, 330 of the sheet 316. In FIG. 13, the sheets 312, 314, 316 are clamped together for preparation of a welding process and facilitating the adhesion between them. FIG. 14 shows the deposition of a GMA spot weld 338 between the sheets 312, 314 which are made from the same material (e.g., aluminum) with the sheet 316 (which is made from magnesium) interlocked between them. As a result the sheet 316 is interlocked with the between the aluminum sheets 312, 314.
The method includes lock-joining together parts made from dissimilar materials through the use of interlocking means on the parts at the joints betwee n them, and the use of another (i.e., secondary) joining process whose application is separate from and confined to joining two parts made from the same material, which ensures that the mechanical interlocks between the parts of dissimilar materials do not become separated.
The term “snug fit” is defined as a gap or space (or a lack thereof between each of the protrusions 40, 42, 44, 46 of the post 12 and the outer surface of the insert 16 being in the range of zero up to a dimension that does not expose a surface of the tube 14 to the welding process. The term “mate” is defined as to join, fit, associate, assemble or couple parts or components with one another. The term “interlock” means to lock, fasten or fix parts or components with one another to ensure a stable and desirable coordinately functioning structure or action.
It should be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. Accordingly, all such variations and modifications are intended to be included within the scope of the embodiments described herein as defined in the appended claims.
Patent Application
20090188206
