A SYSTEM AND METHOD FOR DELIVERING ADHESIVES

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention related to adhesives and, more particularly, to the packaging and application thereof.

2. Description of the Related Art

[0002] Adhesives are used in a multitude of applications. Generally, adhesives are applied to join at least two parts. The adhesives are then allowed to cure into strong materials that hold the surfaces of the at least two parts together with good resistance to stress. Many adhesives are able to withstand harsh environments including moisture, solvent, elevated temperature, and the like. For example, anaerobic adhesives cure in an oxygen-free environment. Anaerobic adhesives are frequently used in a variety of applications including threadlocking.

[0003] Typically, adhesives are packaged in a reservoir, such as a tube or bottle, having a dispensing nozzle. In use, the adhesive is expressed through the dispensing nozzle onto at least one of the parts to be joined. However, conventional methods of delivering adhesive oftentimes lack in consistently delivering exactly the same amount of adhesive, and frequently cannot apply the adhesive into the precise location where the adhesive needs to be applied. For example, in a bolt and a nut assembly, an adhesive is often used to ensure that the assembly is properly secured. In such situations, it is difficult to ensure that the adhesive is precisely applied onto the

threads of the bolt and that the correct amount of the adhesive is applied to join at least two parts without unnecessary waste.

[0004] Accordingly, there is a need for a system for delivering an adhesive that ensures that the adhesive is applied in a precise dose and in the desired location of the assembly when joining at least two parts.

SUMMARY OF THE INVENTION

[0005] According to the present invention, a system for delivering an adhesive to join at least two parts includes a collapsible container for housing the adhesive, where upon application of pressure to the container, the container collapses and the adhesive is applied to join the at least two parts with the remains of the container remaining disposed between the at least two parts to form a washer. The system provides precision in the dosage of adhesive applied and applies the adhesive to the exact, somewhat difficult to access, location.

[0006] According to a feature of the present invention, the system for delivering an adhesive further includes at least one weakened portion that yields under pressure to allow application of adhesive therethrough. According to another feature of the present invention, the system for delivering an adhesive further includes at least one gas permeable portion to allow gas to diffuse therethrough and to come into contact with an adhesive.

[0007] According to yet another feature of the present invention, the system for delivering an adhesive further includes at least one opening to allow at least one part to be joined to pass therethrough.

[0008] According to the present invention, a method for delivering an adhesive includes the steps of providing a container housing a self-contained dose of an adhesive, placing the container between at least two parts to be joined together, and applying pressure to the container to release the self-contained dose of the adhesive therefrom to facilitate joining of the at least two parts.

[0009] The foregoing and other advantages of the present invention become more apparent in light of the following detailed description of the exemplary embodiments thereof, as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a cross sectional view of a system for delivering an adhesive according to the present invention, shown with at least two parts to be joined;

[0011] FIG. 2 is a perspective view of the system for delivering the adhesive of FIG. 1;

[0012] FIG. 3 is an enlarged, exploded cross sectional view of the system for delivering the adhesive of FIG. 1 ;

[0013] FIG. 4 is a cross sectional view of the system for delivering the adhesive of FIG. 1, collapsed and disposed between the at least two parts to be joined;

[0014] FIG. 5 is a perspective partially broken away view of a system for delivering an adhesive according to another embodiment of the present invention;

[0015] FIG. 6 is a perspective view of a system for delivering an adhesive according to a further embodiment of the present invention, shown with at least two parts to be joined;

[0016] FIG. 7 is a cross sectional view of the system for delivering the adhesive of FIG. 6;

[0017] FIG. 8 is an exploded cross sectional view of the system for delivering the adhesive of FIG. 6;

[0018] FIG. 9 is a perspective view of the system for delivering the adhesive of FIG.6, collapsed and disposed between the at least two parts to be joined;

[0019] FIG. 10 is a perspective view of a system for delivering an adhesive according to another embodiment of the present invention, shown with at least two parts to be joined;

[0020] FIG. 11 is an exploded view of the system for delivering the adhesive of FIG. 10;

[0021] FIG. 12 is a perspective view of the system for delivering the adhesive of FIG.10, collapsed and disposed between the at least two parts to be joined;

[0022] FIG. 13 is a perspective view of a system for delivering an adhesive according to a further embodiment of the present invention, shown with at least two parts to be joined;

[0023] FIG. 14 is an exploded view of the system for delivering the adhesive of FIG. 13; and

[0024] FIG. 15 is a perspective view of the system for delivering the adhesive of FIG.13, collapsed and disposed between the at least two parts to be joined.

DETAILED DESCRIPTION OF THE INVENTION

[0025] Referring to FIG. 1, an assembly 10 of at least two parts 12, 14 being joined together includes a system 16 for delivering an adhesive 18. The assembly 10 includes a fastening or support member, such as a bolt 12 having a bolt head 22 with a joining surface 24 and a threaded shaft 26 extending from the joining surface 24 of the bolt head 22. The threaded shaft 26 includes a plurality of threads 28. The assembly 10 also includes a nut 14, complementary to the bolt 12, having a joining surface 30 to be secured onto the bolt 12.

[0026] Referring to FIGS. 1-3, the system 16 for delivering the adhesive 18 includes a container 34 for housing the adhesive 18 therein. The container 34 is constructed to include a first portion 36 and a second portion 38 defining a compartment 40. The container 34 is constructed to include a first opening 44 and a second opening 46 adapted to allow a portion of the threaded shaft 26 to pass therethrough, and a through hole 48 formed between the openings 44, 46 when the first portion 36 and the second portion 38 are joined.

[0027] The first portion 36 includes a first outer sealing region 52, a first intermediate region 54, and a first inner sealing region 56, as best seen in FIGS. 1 and 3. The first intermediate region 54 of the first portion 36 includes a first outer wall 60 and a first inner wall 62 partially defining the compartment 40. Each wall 60, 62 includes an adhesive contact surface 64, 66, respectively, with at least one of the walls 60, 62 constructed to include at least one gas permeable region 70 for the diffusion of gas across at least a portion of the first intermediate region 54. The first outer sealing region 52 extends from the first outer wall 60 and includes a first outer sealing interface 72. The first inner sealing region 56 extends from the first inner wall 62 and includes a first inner sealing interface 74.

[0028] The second portion 38 includes a second outer sealing region 78, a second intermediate region 80, and a second inner sealing region 82. The second intermediate region 80 includes an adhesive contact surface 65 and can be constructed to include a gas permeable region 70 for the diffusion of gas across at least a portion of the second intermediate region 80. The second outer sealing region 78 extends outwardly from the second intermediate region 80 and includes a second outer sealing interface 86, such that when the first portion 36 and the second portion 38 are joined, the first outer sealing interface 72 is in contact with the second outer sealing interface 86 to form an outer seal 88, as best seen in FIGS. 2 and 4. The second inner sealing region 82 extends radially inward from the second intermediate region 80 and includes a second inner sealing interface 90, such that when the first portion 36 and the second portion 38 are joined, the first inner sealing interface 74 is in contact with the second inner sealing interface 90 to form an inner seal 94.

[0029] The container 34 is constructed to include weakened portions 96 and 98, as best seen in FIG. 2. The weakened portion 96 of the container 34 is the inner seal 94 or, alternatively, a plurality of seals 94, or the partial seal 94, that is substantially adjacent to the threads 28 of the threaded shaft 26 when assembled. The container 34 alternatively, or in addition, includes the weakened portion 98, disposed in the inner wall 62 of the first intermediate region 54.

[0030] Referring to FIG. 3, either the outer wall 60 or the inner wall 62 of the first intermediate region 54 of the first portion 36, or the second intermediate region 80 of the second portion 38, in contact with the adhesive 18, includes a gas permeable region 70.

[0031] Referring to FIG. 4, the first intermediate region 54 is fabricated to collapse upon application of pressure to join the bolt 12 with the nut 14 to release the adhesive 18 and to form a washer sandwiched between the joining surfaces 24, 30 of the bolt 12 and the nut 14, respectively.

[0032] Referring to FIG. 5, in another embodiment of the present invention, the system 116 for delivering an adhesive 118 includes a substantially solid second inner sealing region 182 formed within the second portion 138, wherein the like numerals of this embodiment represent the like features in the description and the drawings of FIGS. 1-4. A central portion 183 of the inner sealing region 182 is perforated when the container 134 is placed over the threaded shaft 26 of the bolt 12, or vice versa. The substantially solid inner sealing region 182 can be either solid, scored or pre-perforated to facilitate joining of the at least two parts.

[0033] Referring to FIGS. 6 and 7, in another embodiment of the present invention, an assembly 210 of at least two parts 212, 214 being joined together includes a system 216 for delivering an adhesive 218. The assembly 210 includes a bolt 212 and a nut 214, wherein the like numerals of this embodiment for the bolt 212 and the nut 214 represent the like features in the description and the drawings of FIGS. 1-4. The system 216 for delivering the adhesive 218 also includes a container 234 for housing the adhesive 218 therein. The container 234 includes a first portion 236 and a second portion 238 defining a compartment 240. The container 234 further includes a first opening 244, a second opening 246, and a through hole 248 formed between the openings 244, 246 when the first portion 236 and the second portion 238 are joined.

[0034] Referring to FIG. 8, the first portion 236 includes a first outer sealing region 252, a first intermediate region 254, and a first inner sealing region 256. The first intermediate region 254 of the first portion 236 includes a first outer wall 260 and a first inner wall 262 partially defining the compartment 240. Each wall 260, 262 includes an adhesive contact surface 264, 266, respectively, with at least one of the walls 260, 262 including at least one gas permeable region 270 for the diffusion of gas across at least a portion of the first intermediate region 254. The first outer sealing region 252 extends from the first outer wall 260 and includes a first outer sealing interface 272. A first inner sealing interface 274 is formed in the first inner sealing region 256 on the first inner wall 262.

[0035] The second portion 238 includes a second outer sealing region 278, a second intermediate region 280, and a second inner sealing region 282. The second intermediate region 280 of the second portion 238 includes a second outer wall 261 and a second inner wall 263 partially defining the compartment 240. Each wall 261, 263 includes an adhesive contact surface 265, 267, respectively, with at least one of the walls 261, 263 including at least one gas permeable region 270 for the diffusion of gas across at least a portion of the second intermediate region 280. Alternatively, the gas permeable region 270 can be formed in any portion of the container to allow for the diffusion of gas.

[0036] The second outer sealing region 278 extends from the second intermediate region 280 and includes a second outer sealing interface 286 to form an outer seal 288, as best seen in FIG. 6, when the first portion 236 and the second portion 238 are joined. A second inner sealing

interface 290 is formed in the second inner region 282 ^" on the second inner wall 263, as seen in FIG. 8, such that when the first portion 236 and the second portion 238 are joined, the first inner sealing interface 274 is in contact with the second inner sealing interface 290 to form an inner seal 294, as seen in FIG. 7.

[0037] The container 234 further includes weakened portion 296 and 298. The weakened portion 296 of container 234 is the inner seal 294 or, alternatively, a plurality of seals 294, or a partial seal 294 that is substantially adjacent to the thr-eads 228 of the threaded shaft 226 when assembled. The container 234 alternatively, or in additon, includes the weakened portion 298 disposed in the inner wall 262 or the inner wall 263 of the first intermediate region 254 or the second intermediate region 280, respectively.

[0038] Either the outer walls 260, 261 or the inner walls 262, 263 of the first or second intermediate regions 254, 280, respectively, in contact with the adhesive 218, include a gas permeable region 270.

[0039] Referring to FIG.9, the first intermediate region 254 of the first portion 236 and the second intermediate region 280 of the second portion 238 are fabricated to collapse upon application of pressure, to join the bolt 212 with the nut 214, to release the adhesive 218 and to form a washer sandwiched between the joining surfaces 224, 230 of the bolt 212 and the nut 214.

[0040] Referring to FIG. 10, in a further embodiment of the present invention, an assembly 310 of at least two parts 312, 314 being joined together includes a system 316 for delivering an adhesive 318. The parts 312, 314 include a joining surface 324, 330, respectively.

[0041] Referring to FIGS. 10 and 11, the system 316 for delivering the adhesive 318 includes a container 334 for housing the adhesive 318 therein. The container 334 includes a first portion 336 and a second portion 338 defining a compartment 340. The first portion 336 includes a first sealing region 352 and a first intermediate region 354. The first intermediate region 354 of the first portion 336 includes a wall 360, or a plurality of walls 360, partially defining the compartment 340. The wall 360 or the plurality of walls 360 includes an adhesive contact surface 364, with the wall 360 or at least one of the plurality of walls 360 including a gas permeable region 370 for the diffusion of gas across at least a portion of the first intermediate region 354. The first sealing region 352 extends substantially peripherally from the wall 360 or the plurality of walls 360 and includes a first sealing interface 372.

[0042] The second portion 338 includes a second sealing region 378 and a second intermediate region 380. The second intermediate region 380 includes an adhesive contact surface 365 and can include a gas permeable region 370 for the diffusion of gas across at least a portion of the second intermediate region 380. The second sealing region 378 extends substantially peripherally from the second intermediate region 380 and includes a second sealing interface 386, such that when the first portion 336 and the second portion 338 are joined, the first sealing interface 372 is in contact with the second sealing interface 386 to form a seal 388 substantially on the periphery of the intermediate regions 354, 380.

[0043] The container 334 further includes weakened portions 396 and 398. The weakened portion 396 of the container 334 is the outer seal 388 or, alternatively, a plurality of seals 388, or a portion of the seal 388. The container 334 alternatively, or in addition, includes the weakened portion 398, disposed in the wall 360 or in the plurality of walls 360 of the first intermediate region 354 of the first portion 336, or in the second intermediate region 380 of the second portion 338.

[0044] Referring to FIG. 12, the first and second intermediate regions 354, 380 are fabricated to collapse upon application of pressure to join the parts 312, 314 to release the adhesive 318 and sandwich the container 334 between the joining surfaces 324, 330 of the parts 312, 314. A gap 399 is formed between the parts 312 and 314 to accommodate the thickness of the collapsed container 334.

[0045] Referring to FIG. 13, in a further embodiment of the present invention, an assembly 410 of at least two parts 412, 414 being joined together includes a system 416 for delivering an adhesive 418. The parts 412, 414 include a joining surface 424, 430, respectively, and the part 412 further includes a cavity 431.

[0046] Referring to FIGS. 13 and 14, the system 416 for delivering the adhesive 418 includes a container 434 for housing the adhesive 418 therein. The container 434 includes a first portion 436 and a second portion 438 defining a compartment 440. The first portion 436 includes a first sealing region 452 and a first intermediate region 454. The first intermediate region 454 includes an adhesive contact surface 464 and can include a gas permeable region 470

for the diffusion of gas across at least a portion of the first intermediate region 454. The first sealing region 452 extends peripherally from the first intermediate region 454 and includes a first outer sealing interface 472.

[0047] The second portion 438 includes a second sealing region 478 and a second intermediate region 480. The second intermediate region 480 includes an adhesive contact surface 465 and can include a gas permeable region 470 for the diffusion of gas across at least a portion of the second intermediate region 480. The second sealing region 478 extends peripherally from the second intermediate region 480 and includes a second sealing interface 486, such that when the first portion 436 and the second portion 438 are joined, the first sealing interface 472 is in contact with the second sealing interface 486 to form a seal 488 substantially on the periphery of the first and second intermediate regions 454, 480 of the first and second portions 336, 338, respectively.

[0048] The container 434 further includes weakened portions 496 and 498. The weakened portion 496 of the container 434 is the outer seal 488 or, alternatively, a plurality of seals 488, or a portion of the seal 488. The container 434 alternatively, or in addition, includes the weakened portion 498, disposed in the first intermediate region 454 of the first portion 336 and/or the second intermediate region 480 of the second portion 438.

[0049] The cavity 431 of the part 414 accommodates at least a portion of the container 434. In the present embodiment, the cavity 431 of the part 414 is dimensioned to position and hold substantially the entire container 434.

[0050] As seen in FIG. 15, the first and second intermediate regions 454, 480 of the present embodiment are fabricated to collapse upon application of pressure to join the parts 412, 414 to release the adhesive 418 and join the parts 412, 414, such that the container 434 remains sandwiched between the parts 412, 414 and substantially all of the container 434, which has collapsed, is disposed in the cavity 431 of the part 414.

[0051] In operation, the system 16 is deployed to join the bolt 12 and the nut 14, the combination as best seen in FIG. 1. The threaded shaft 26 of the bolt 12 is passed through the through hole 48 of the container 34, such that the container 34 is positioned substantially adjacent to the joining surface 24 of the bolt head 22. The threaded shaft 26 threadably engages the nut 14 at the joining surface 30 and the bolt 12 or the nut 14 is actuated such that the joining surfaces 24, 30 of the bolt 12 and the nut 14, respectively, move proximate to each other to sandwich the container 34 between the joining surfaces 24, 30.

[0052] As pressure is applied to either the bolt 12 or the nut 14, the weakened portions 96 and/or 98 yield in a random or predetermined order to allow application of the adhesive 18 onto the threads 28 of the threaded shaft 26. The weakened portion 96 can be fabricated to fail before the weakened portion 98, allowing the adhesive 18 to pass through the weakened portion 96 and contact the threads 28 of the threaded shaft 26 before the weakened portion 98 fails, and as further pressure is applied, to allow the adhesive 18 to also contact the threads 28 from the weakened portion 98, or vice versa.

[0053] As further pressure is applied, the walls 60, 62 of the first intermediate region 54 of the first portion 36 fail, the rest of the adhesive 18 is allowed to contact the threads 28 of the threaded shaft 26, and the container 34 collapses, as seen in FIG. 4. The self-contained dose of the adhesive 18 is thus applied to join the bolt 12 and nut 14 and the container 34 remains sandwiched between the nut 14 and the head 22 of the bolt 12.

[0054] In the embodiment of FIG. 5, the system 116 for delivering the adhesive 118 is deployed to join the bolt 12 with the nut 14, as in the embodiment of FIG. 1, except that the system 116 further includes the solid sealing region 182 having the central portion 183 which is perforated when the container 134 is placed over the threaded shaft 26 of the bolt 12, or vice versa.

[0055] In the embodiment of FIG. 6, the system 216 for delivering the adhesive 218 is deployed to join the bolt 212 and the nut 214. The container 34 is sandwiched between the joining surfaces 234, 230 of the bolt 12 and the nut 14, respectively, and as pressure is applied to either the bolt 212 or the nut 214, the weakened portions 296 and/or 298 yield in a random or predetermined order to allow application of the adhesive 218 onto the threads 228 of the threaded shaft 226.

[0056] The weakened portion 296 can be fabricated to fail before the weakened portion 298, allowing the adhesive 218 to pass through the weakened portion 296 and contact the threads 228 of the threaded shaft 226 before the weakened portion 298 fails, and as further pressure is

applied, to allow the adhesive 218 to also contact the threads 228 from the weakened portion 298, or vice versa.

[0057] As further pressure is applied, the outer walls 260, 261 and/or the inner walls 262, 263 of the first and second intermediate regions 254, 280 of the first and second portions 236, 238, respectively, fail in a random or predetermined order. The rest of the adhesive 18 is allowed to contact the threads 228 of the threaded shaft 226, and the container 234 collapses. The self-contained dose of the adhesive 218 is thus applied to join the bolt 212 and nut 214, and the container 234 remains sandwiched between the nut 214 and the head 222 of the bolt 212, as seen in FIG. 9.

[0058] In the embodiment of FIG. 10, the system 316 for delivering the adhesive 318 is deployed to join the part 312 with the part 314. The container 334 is positioned on the joining surface 330 of the part 314, and the parts 312, 314 are moved proximate to each other to sandwich the container 334 between the joining surfaces 324, 330 of the parts 312, 314, respectively.

[0059] As pressure is applied to either of the parts 312, 314, the weakened portions 396 and/or 398 yield in a random or predetermined order to allow application of the adhesive 318 onto the joining surfaces 324, 330. The weakened portion 398 can be fabricated to fail before the weakened portion 396 fails, allowing the adhesive 318 to pass through the weakened portion 398 first and contact the joining surfaces 324, 330, or vice versa. As more pressure is applied,

the weakened portion 396 fails to allow the adhesive 318 to also contact the joining surfaces 324, 330 through the weakened portion 396.

[0060] As further pressure is applied, the wall 360 or the plurality of walls 360 of the first intermediate region 354 of the first portion 336, and/or the second intermediate region 380 of the second portion 338 fail in a random or predetermined order. The rest of the adhesive 318 is allowed to contact the joining surfaces 324, 330 of the two parts 312, 314, respectively, and the container 334 collapses, as seen in FIG. 12. The self-contained dose of the adhesive 318 is thus applied to join the two parts 312, 314 and the container 334 remains sandwiched between the parts 312, 314. In the present embodiment, the gap 399 is formed between the substantially flat parts 312, 314 to accommodate the thickness of the collapsed container 334.

[0061] In the embodiment of FIG. 13, the system 416 for delivering adhesive 418 is deployed to join the part 412 with the part 414. The container 434 is positioned in the cavity 431 of the part 414, and the parts 412, 414 are moved proximate to each other to sandwich the container 434 between the joining surfaces 424, 430 of the parts 412, 414, respectively.

[0062] As pressure is applied to either of the parts 412, 414, the weakened portions 496 and/or 498 yield in a random or predetermined order to allow application of the adhesive onto the parts 412, 414. The weakened portion 498 can be fabricated to fail before the weakened portion 496 fails, allowing the adhesive 418 to pass through the weakened portion 498 first. As more pressure is applied, the weakened portion 496 fails to allow the adhesive 418 to contact the

cavity 431 and the joining surface 430 of the part 414 and/or the joining surface 424 of the part 412 through the weakened portion 496.

[0063] As further pressure is applied, the first intermediate region 454 of the first portion 436, and/or the second intermediate region 480 of the second portion 438 fail in a random or predetermined order. The rest of the adhesive 418 is allowed to contact the cavity 431, the joining surface 430 of the part 414 and the joining surface 424 of the part 412, and the container 434 collapses in the cavity 431, as seen in FIG.-15. The self-contained dose of the adhesive 418 is thus applied to join the two parts 412, 414 and the container 434 remains sandwiched between the cavity 431 of the part 414 and the joining surface 424 of the part 412 such that no gap is formed when the parts 412, 414 are joined.

[0064] The system of the present invention is not limited to the embodiments seen in FIG. 1, FIG. 6, FIG. 10, or FIG. 13. Other shapes that are employed for the overall system 16, 116, 216, 316, 416, or for the portions 36, 38, 136, 138, 236, 238, 336, 338, 436, 438 include, but are not limited to, rectangular, square, or hexagonal. Similarly, the openings 44, 46, 244, 246, or the through hole 48, 248, of the container 34, 234, for example, may be of any geometry.

[0065] The container 34, 134, 234, 334, 434 is fabricated from any composition suitable to house an adhesive 18, 118, 218, 318, 418 including, but not limited to, polymeric compositions such as polyethylene or composite compositions such as polypropylene and polyethylene or polyester and polyethylene. Any composition suitable to house an adhesive 18, 118, 218, 318, 418 can be modified to achieve mechanical or chemical properties such as strength, stress, strain,

toughness, hardness, fatigue, stiffness, compatibility with the adhesive housed therein, etc. Thus, if a composite composition is employed, then polyethylene, for example, can be used for surfaces of the container 34, 134, 234, 334, 434 contacting the adhesive 18, 118, 218, 318, 418 housed therein, and polypropylene can be used for surfaces requiring rigidity and also gas diffusivity.

[0066] The adhesive 18, 118, 218, 318, 418 within the container 34, 134, 234, 334, 434 may be an anaerobic type of adhesive. In such case, (meth)acrylate monomers are used as the curable matrix. The (meth)acrylate monomers may be chosen from a wide variety of materials, such as those represented by H ₂ C=CGCO ₂ R ¹ , where G may be hydrogen, halogen or alkyl groups having from 1 to about 4 carbon atoms, and R ¹ may be selected from alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkaryl, aralkyl or aryl groups having from 1 to about 16 carbon atoms, any of which may be optionally substituted or interrupted as the case may be with silane, silicon, oxygen, halogen, carbonyl, hydroxyl, ester, carboxylic acid, urea, urethane, carbonate, amine, amide, sulfur, sulfonate, sulfone and the like.

[0067] Mono-functional (meth)acrylates like hydroxyethyl (meth)acrylate ("HEMA"), hydroxypropyl (meth)acrylate ("HPMA"), isobornylacrylate ("IBOA"), and the like may be suitable for use herein, particularly in combination with a di- or tri-functional (meth)acrylate, as set forth below.

[0068] Additional (meth)acrylate monomers suitable for use herein include polyfunctional (meth)acrylate monomers, such as di-or tri-functional (meth)acrylates like polyethylene glycol

di(meth)acrylates ("PEGMA"), tetrahydrofuran (meth)acrylates and di(meth)acrylates, hexanediol di(meth)acrylate, trimethylol propane tri(meth)acrylates ("TMPTMA"), diethylene glycol dimethacrylate, triethylene glycol dimethacrylates ("TRIEGMA"), tetraethylene glycol di(meth)acrylates, dipropylene glycol di(meth)acrylates, di-(pentamethylene glycol) ■ di(meth)acrylates, tetraethylene diglycol di(meth)acrylates, diglycerol tetra(meth)acrylates, tetramethylene di(meth)acrylates, ethylene di(meth)acrylates, neopentyl glycol di(meth)acrylates, and bisphenol-A mono and di(meth)acrylates, such as ethoxylated bisphenol- A (meth)acrylate ("EBIPMA"), and bisphenol-F mono and di(meth)acrylates, such as ethoxylated bisphenol-A (meth)acrylate.

[0069] Still other (meth)acrylate monomers that may be used herein include silicone (meth)acrylate moieties ("SiMA"), such as those taught by and claimed in U.S. Patent No. 5,605,999 (Chu), the disclosure of which is hereby expressly incorporated herein by reference.

[0070] Of course, combinations of these (meth)acrylate monomers may also be used.

[0071] The (meth)acrylate monomer should comprise from about 10 to about 90 percent by weight of the adhesive, such as about 60 to about 90 percent by weight, based on the total weight of the adhesive.

[0072] Recently, additional components have been included in traditional anaerobic adhesives to alter the physical properties of either the formulation or the reaction products thereof.

[0073] For instance, one or more of maleimide components, thermal resistance-conferring coreactants, diluent components reactive at elevated temperature conditions, mono- or poly- hydroxyalkanes, polymeric plasticizers and chelators (see U.S. Patent No. 6,391,993, the disclosure of which is hereby expressly incorporated herein by reference) may be included to modify the physical property and/or cure profile of the formulation and/or the strength or temperature resistance of the cured adhesive.

[0074] When used, the maleimide, coreactant, reactive diluent, plasticizer, and/or mono- or poly-hydroxyalkanes, may be present in an amount within the range of about 1 percent to about 30 percent by weight, based on the total weight of the adhesive.

[0075] Other conventional components, such as an anaerobic cure-inducing composition, which oftentimes include one or moie free radical initiators and inhibitors of free radical generation, as well as metal catalysts should also be included in the adhesive.

[0076] A number of well-known initiators of free radical polymerization are typically incorporated into the inventive compositions including, without limitation, hydroperoxides, such as cumene hydroperoxide ("CHP"), para-menthane hydroperoxide, t-butyl hydroperoxide ("TBH") and t-butyl perbenzoate. Other peroxides include benzoyl peroxide, dibenzoyl peroxide, l,3-bis(t-butylperoxyisopropyl)benzene, diacetyl peroxide, butyl 4,4-bis(t- butylperoxy)valerate, p-chlorobenzoyl peroxide, cumene hydroperoxide, t-butyl cumyl peroxide, t-butyl perbenzoate, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di-t-

butylperoxyhexane, 2,5-dimethyl-2,5-di-t-butyl-peroxyhex-3-yne, 4-methyl-2,2-di-t- butylperoxypentane and combinations thereof. Such peroxide compounds are typically employed in the present invention in the range of from about 0.1 to about 10 percent by weight, based on the total weight of the adhesive, with about 1 to about 5 percent by weight being desirable.

[0077] Stabilizers and inhibitors (such as phenols including hydroquinone and quinones) may also be employed to control and prevent premature peroxide decomposition and polymerization of the composition of the present invention, as well as chelating agents [such as the tetrasodium salt of ethylenedi amine tetraacetic acid ("EDTA")] to trap trace amounts of metal contaminants therefrom. When used, chelating agents may ordinarily be present in the adhesive in an amount from about 0.001 percent by weight to about 0.1 percent by weight, based on the total weight of the adhesive.

[0078] Metal catalyst solutions or pre-mixes thereof are used in amounts of about 0.03 to about 0.1 percent by weight.

[0079] Still other additives, such as thickeners, non-reactive plasticizers, fillers, and toughening agents (such as elastomers and rubbers), may be incorporated into the adhesive where the art- skilled believes it would be desirable to do so.

[0080] In the case where the adhesive 18, 118, 218, 318, 418 is an anaerobic type of adhesive, it is housed within the container 34, 134, 234, 334, 434 in an uncured state. Referring

to the embodiments seen in FIG. 1, FIG. 6, FIG. 10, or FIG. 13, for example, oxygen diffuses into the chamber 40, 240, 340, 440 of the container 34, 234, 334, 434 through the gas permeable region or regions 70, 270, 370, 470. The adhesive 18, 218, 318, 418 cures due to a lack of oxygen when it is enclosed within the bolt 12, 212 and the nut 14,214, respectively, or enclosed within the parts 312,412 and 314,414, respectively.

[0081] The gas permeable region or regions 70, 170, 270, 370, 470 are fabricated using mechanical, thermal, or chemical means, and combinations thereof. Furthermore, the gas, which is allowed to diffuse through the gas permeable region 70, 170, 270, 370, 470, includes, but is not limited to, oxygen. In the case where the container 34, 134, 234, 334, 434 comprises more than one ingredient, such as in the case of a composite, the gas permeable region 70, 170, 270, 370, 470 can be disposed at each layer of the composite, such as when a composite of polypropylene and polyethylene is used. In the case where the adhesive 18, 118, 218, 318, 418 housed within the container 34, 134, 234, 334, 434 is not an anaerobic type of adhesive, the gas permeable region 70, 170, 270, 370, 470 can be excluded, for example, by employing a composite composition of polyester and polyethylene ingredients.

[0082] The seals 88, 94, 188, 194, 288, 294, 388, 488 are sealed, for example, mechanically, thermally or a chemically, and combinations thereof. Referring back to FIGS. 2, 5, 7, 10 and 13, for example, the outer seals 88, 188, 288, the inner seals 94, 194, 294 and/or the seals 388, 488 are substantially continuous seams in the preferred embodiments of the present invention, although the seals 88, 94, 188, 194, 288, 294, 388, 488 can be either a plurality of seams or be partially sealed. The inner seals 94, 194, 294, for example, are fabricated to fail before the outer

seals 88, 188, 288 fail to form the weakened portion, and the inner seals 94,194, 294 are weaker as compared to the outer seals 88, 188, 288 by virtue of having a smaller seal area.

[0083] The weakened portions 98, 198, 298, 398, 498 of the container 34, 134, 234, 334, 434, respectively, can be fabricated by either molding attenuated inner wall or wall sections, or by mechanically weakening, for example, the inner wall 62, 162, the inner wall 262 or the inner wall 263, or the wall 360 or the plurality of walls 360 of the first intermediate region 354 of the first portion 336, or the second intermediate region 380 of the second portion 338. Similarly, the weakened portion 498 can be fabricated by either molding or by mechanically weakening the first and/or second intermediate regions 454, 480 of the first and/or second portions 436, 438, respectively.

[0084] The mechanical weakening can be effectuated by partial scoring or deforming the inner wall 62, 162, the inner wall 262 or the inner wall 263, the wall 360 or the plurality of walls 360 of the first intermediate region 354 of the first portion 336, or the second intermediate region 380 of the second portion 338, or the first and/or second intermediate regions 454, 480 of the first and/or second portions 436, 438, respectively.

[0085] The weakened portions 96, 98, 196, 198, 296, 298, 396, 398, 496, 498 are not mutually exclusive, are not limited to the examples herein, and thus may be employed in any desired combination, location, and configuration. Furthermore, various order of failure is within the scope of the present invention. Referring to the embodiments seen in FIG. 1 and 6, for example, the order of failure can be tailored for each individual weakened portion 96, 98, 296,

298 in addition to the failure order between the weakened portions 96, 98, 296, 298 by, for example, fabricating the plurality of seals 94 to fail in a predetermined or random order, or fabricating the weakened portion 298 disposed in one section of the inner wall 262 to fail in a random or predetermined order with regards to the weakened portion 298 disposed in another section of the inner wall 262 of the first intermediate region 254.

[0086] The parts to be joined are not limited to the configurations seen in FIG. 1, FIG. 6, FIG. 10, or FIG. 13. Other configurations to be employed include, but are not limited to, screw and nut configurations such as, for example, cap screws and set screws, and any appropriate nuts including, for example, square nuts. Moreover, the screw and bolt configurations include varying geometries such as, for example, pan head, button head, round head, truss head, flat head or oval head geometries. Furthermore, the parts to be joined can be modified to position the container 34, 134, 234, 334, 434 such as, for example, providing protrusions in addition to, or in lieu of, cavities 431 in the embodiment of FIG. 13.

[0087] According to the present invention, the system 16, 116, 216, 316, 416 provides for a precise dosage of the adhesive 18, 118, 218, 318, 418 applied and precise positioning of the applied adhesive 18, 118, 218, 318, 418 to the substrate for improved efficiency when administering the adhesive between at least two parts to be joined. The system 16, 116, 216, 316, 416 includes a precise dosage of adhesive 18, 118, 218, 318, 418 to be applied. Moreover, the system 16, 116, 216, 316, 416 can be positioned such that the adhesive 18, 118, 218, 318, 418 is applied in a predetermined or random manner on the desired location of the substrate.