TOBO ACCESSORY AND ASSEMBLY METHOD This application corresponds to a continuation-in-part of the U.S. Patent Application. Serial No. 08 / 445,282 filed May 19, 1995, which is a divisional application of the U.S. Patent Application. Serial number
08 / 233,846 filed April 26, 1994. BACKGROUND OF THE INVENTION Accessory and tube structures have been designed in many different configurations and assembly methods. The usual case of a telescoped tube on a part of an accessory is when jaws of some type have compressed in a generally radial manner the tube, in sealing contact with that part of the pipe and telescoped fittings. In this case, the tube is compressed radially inward to effect the seal. This is in fact very difficult to make a good seal because the tube, even though it is malleable and deforms beyond its elastic limit, tends to have a certain amount of elasticity and spring or return neck radially outwards after that the oppression of the gag has been removed. In this way, in many cases, the fluid-tight seal between the tube and the fitting is destroyed or at least reduced in terms of the pressure of the fluid it will support. Additionally, at high temperatures, the tube and / or accessory can relax. In this way in many cases, the fluid-tight seal between the tube and the accessory is destroyed or at least reduced in terms of the temperature it will withstand. SUMMARY OF THE INVENTION The present invention provides an accessory and tube structure and assembly method, wherein radial expansion does not occur after the pressure of the structure is removed and the jaws of the structure move longitudinally relative to the tube to give its compression. This longitudinal relative movement causes the tube to bulge outward and bulge inward facing the jaws during relative movement, so that if there is some relaxation of the tube when it is removed to the pressure, this relaxation is radially inward instead of outside. This ensures a fluid tight seal that withstands the pressure to the bursting pressure of the tube at relatively high temperatures. Accordingly, the accessory and tube structure of the present invention includes a malleable tube and an attachment having a first portion forming an external surface, a second portion radially larger than the first portion, to form a confinement oriented to the first portion, and a recess formed between the confinement and oriented to the first portion. One end of the tube is compressed radially inwardly on the outer surface of the fitting and extends into the recess of the fitting to make a fluid-tight seal between the tube and the fitting, which bears a fluid pressure inside the tube. Preferably, a seal member is provided within the recess. One method for assembling of the present invention includes placing the tube on the first portion of the fitting and the outer surface and holding the tube with jaws having a nose portion inward of a small axial extension, approximately at the front end of the fitting. . The tube fitting moves longitudinally relative to the jaws to longitudinally compress the tube forward of the nose projection to deform the tube radially inward against the fitting. A portion of the tube extends into the recess to form a seal between the tube and the fitting. Preferably, the tube extends into the recess either by expanding the tube longitudinally within the recess, during the relative longitudinal movement stage or by inserting the tube longitudinally into the recess during the step of placing the tube on the first portion of the attachment. . BRIEF DESCRIPTION OF THE DRAWINGS These and further features of the present invention will be apparent with reference to the following description and drawings, in which: Figure 1 is a longitudinal cross-sectional view of a pipe and fitting ready for assembly;
Figure 2 is a longitudinal cross-sectional view of the tube and accessory of Figure 1, as the assembly is started; Figure 3 is a longitudinal cross-sectional view of the tube and accessory of Figure 2, as the assembly is partially completed; Figure 4 is a longitudinal, cross-sectional view of the tube and accessory of Figure 3 as the assembly is completed; Figure 5 is a longitudinal view, in cross section, view similar to Figure 2, but showing the tube and fitting according to a variation of the present invention; Figure 6 is a longitudinal, cross-sectional view of the tube and accessory of Figure 5, as the assembly is partially completed; Figure 7 is a longitudinal, cross-sectional view of the tube and fitting of Figure 6, as the assembly is completed, - Figure 8 is a longitudinal view, in cross-section, similar to Figure 2, but showing shows a tube and fitting according to another variation of the present invention;
Figure 9 is a longitudinal, cross-sectional view of the tube and accessory of Figure 8 as the assembly is partially completed; Figure 10 is a longitudinal, cross-sectional view of the tube and fitting of Figure 9 as the assembly is completed; Figure 11 is a longitudinal view, in cross-section, cross-sectional view similar to Figure 2, but showing a tube and fitting according to yet another variation of the present invention; Figure 12 is a longitudinal, cross-sectional view of the tube and accessory of Figure 11 as the assembly is partially completed; and Figure 13 is a longitudinal, cross-sectional view of the tube and accessory of Figure 12 as the assembly is completed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figures 1 to 4 illustrate a method for assembling an accessory structure and tube 20 according to the present invention. As best illustrated in Figure 1, a rigid fixture 22 has a generally cylindrical front portion 24 and a generally cylindrical rear portion 26. The rear portion 26 of the fixture 22 can provide a resilient key holder such as a hexagonal surface. The front portion 24 is sized to extend into a malleable tube 26 and has an outer diameter smaller than the outside diameter of the back portion 26, to form a front frontal surface or longitudinal confinement 30. The confinement 30 is substantially perpendicular to the surface peripheral portion of the front portion 24 of the accessory 22. Formed in the confinement 30, there is a recess or groove facing forward and annular 32. The recess 32 is sized and located to receive a portion of the end of the tube 28, as Tube 28 expands during assembly as described in more detail below. The recess 32 forms an annular bottom surface, which is lowered longitudinally from the confinement 30. Preferably, a gasket 34 is provided at the rear end or "recess bottom" 32 as illustrated in Figures 1 to 4. The package 34 is preferably formed of a material that withstands high temperatures such as for example silicone. Alternatively, the package 34 may be an epoxy, sealant, or other convenient sealing member. At the front portion 24 of the fitting 22 a radially shaped and recessed groove or recess 36 is provided, that is, a cylindrical surface 38 having a diameter smaller than the outer diameter of the remainder of the front portion 24. slot 36 and the cylindrical surface 38 are contiguous with the confinement 30. Also at the front portion 24 of the accessory, at least one prong 40 is provided. The accessory of the embodiment illustrated has two annular tines 40, that is, prongs 40 which extend continuously around the periphery of the front portion 24 of the accessory 22. The prongs 40 are preferably annular, so that a seal can be obtained between the prongs 40 of the accessory 22 and the tube 28. The prongs 40 are preferably located between the slots 36 and the front end of the accessory 22. Each tine 40 has an inclined surface 42 facing the front end of the accessory 22 and has a locking surface 44 that is oriented away from the front end of the accessory 22. The interlocking surface 44 is substantially perpendicular to the peripheral surface of the front portion 24 of the accessory 22. As best illustrated in Figure 1, the tube 28 is positioned over the front portion 24 of the accessory 22. The tube 28 can telescope freely on the front portion 24 of the accessory 22 or can make a frictional fit with the prongs 40 which in fact scrape about the lower diameter of the tube 28. A portion of the end of the tube 28 engages the confinement 30 adjacent the recess 32. As best illustrated in Figure 2, two jaws 46 are clamped in the tube 28 near the front end of the accessory 22 and interlock in position. It is noted that while the illustrated embodiment uses two jaws 46, more jaws 46 may be employed. Each jaw 46 is provided with a radially inwardly extending nose projection 48, which contacts the outer surface of the tube 28. Nose projections 48 are of limited axial length with respect to the front portion 24 of the fitting 22. When the jaws 46 are clamped in the tube 28 as illustrated in Figure 2, the nose inward projections 48 of the jaws 46 compress inwardly. the tube 28 for making a substantially annular nose ring 50. The nose ring 50 is annular except for the division between the jaws 46. The jaws 46 also have a small front extension 52 and a longer rear extension 54. The front extension 52 preferably has a small spacing from the outside diameter of the tube 28. The rear extension 54 has essentially the same amount of spacing from the tube 28, to guide the tube 28 between the jaws 46. A longitudinal force is applied to initiate the assembly method by providing relative movement between the jaws 46 and the fitting 22. Relative movement can be obtained by moving the jaws longitudinally. 46 in a rearward direction with respect to the stationary attachment 22, or by longitudinally moving the attachment 22 in a forward direction relative to the stationary jaws 46. In the illustrated embodiment, the longitudinal force 56 is applied to a die 58 which is brought into contact against the rear end of the fitting 22 while the jaws 46 are held stationary in a fixed position. Therefore, the relative longitudinal movement is provided between the die 58 and the jaws 46 and also between the fitting 22 and the telescoping tube 28 and the jaws 46. When the assembly method is approximately complete in half, as best illustrated in Figure 3, the jaws 46 are closed and do not spring open as the relative longitudinal movement advances. The metal material of the tube 28, which is malleable, forms a bulge extending radially outwardly 60, in front of the advancing nose ring 50. The bulge 60 can be restricted radially by the forward extension 52 of the jaws 46. The movement relative longitudinal also causes the malleable tube 28 to bulge radially inwardly and generally circulate radially inwardly against the inclined surfaces 42 of the tines 40 and against the cylindrical surface 38. As best illustrated in Figure 4, the relative longitudinal movement is stops when the nose projections 48 of the jaws 46 are adjacent to the confinement 30 of the accessory 22. The circulating metal caused by this relative longitudinal movement, causes the rear end of the tube 28 to be stuck longitudinally against the confinement 30, which will contract radially inwardly over the length of the fitting and against the cylindrical surface 38 of the groove 36 and the inclined surfaces 42 of the tines 40, and expand longitudinally within the recess 32 against the packing 34. Figure 4 illustrates the structure of the fitting and tube 20, when complete except for the removal of the die 58 and the jaws 46. The material of the tube substantially fills both the groove 36 and the groove. recess 32. It has been found that a fluid tight seal can be obtained on each of the tines 40, cylindrical surface 38, confinement 30, and recess 32. This seal is established by the relative longitudinal movement without any radial compression inward of the jaws 46 as the jaws 46 move longitudinally relative to the die 58. There is initial radial inward compression only in the nose ring 50. At least when the longitudinal force 56 is removed and the jaws 46 are removed from the tube 28, any relaxation of the tube 28 is a radially inward relaxing rather than a radially outward relaxing, as in the prior art . It has been found that the tube 28 expands somewhat radially outwardly adjacent the confinement 30, expands longitudinally backwardly in the recess 32 and in sealing engagement with the packing 34, and contracts radially inwardly in sealing engagement with the cylindrical surface 38. of the groove 36 due to the metal flow of the malleable tube 28. It has been found that the seal of the accessory structure and tube 20 will withstand 703 kg / cm2 (1000 psi) of fluid pressure and will make a tight seal until minus the bursting pressure of the tube itself 28. In tube structures and fittings 20 that have been tested and constructed in accordance with the invention, the prongs 40 have been annular prongs approximately .038 cm (.015") to .076 cm ( .030") greater radially than the cylindrical outer surface of the front portion 24 to the accessory 22. For example, if the tube 28 employed is of external diameter of .953 cm (3/8"), the standard tolerance of at is ± .010 cm (.004") and the wall thickness is .081 cm (.032"). This tube and accessory structure 20 can withstand the trap pressure of 196.84 kg / cm2 (2,800 psi) of the tube 28. Even if a number of accessories 22 are manufactured and all are mixed together in a loading tray, this can imposing slight notches on the tines 40, but it has been found that these notches are filled by the metal flow of the tube or at the time when the accessory structure is completed as illustrated in Figure 4. In any event, an airtight seal The fluid is effected on the cylindrical surface 38, in the confinement 30 and in the recess 32, such that all of the seals prevent leakage to the bursting pressure of the tube 28. This seal is maintained at high temperatures such as for example up to at least 260 ° C ((500 ° F) .It is noted that all the seals also allow the tines 40 to be removed, if desired.For tube with external diameter of .318 cm (1/8") ), the standard commercial tolerance is ± .005cm (.002") and a wall thickness of .071 cm (.028"). In this case the prongs 40 can typically be .013 to .038 cm (.005 to .015") in radial extension beyond the cylindrical outer surface of the front portion 24 of the accessory 22. Figures 5 to 7 illustrate a tube structure and accessories 62 which is a variation of the tube and accessory structure 20 described above with respect to Figures 1 to 4, wherein like reference numerals are employed for similar structures.The tube and accessory structure 62 is the same except that a tube 64, which has a thinner wall thickness with respect to the tube 28, is used in conjunction with a sleeve 66. The sleeve 66 is necessary, each time the tube 64 has a wall thickness that is too thin to consistently form the seals as described above. The sleeve 66 has an inner diameter sized to receive the tube 64 and a length extending at least from the confinement 30 of the front end of the accessory 22. The sleeve 66 has a suitable wall thickness to form the seals in conjunction with the thickness of the tube 64. The sleeve 66 is preferably formed of a malleable metal and preferably is formed of the same material as the tube 64. The method of assembly is the same as that described above except that both the tube 64 and the tube sleeve 66 are deformed by the nose projection 46 of the jaws 40, to form the seals. Although the sleeve 66 is only described in detail with respect to the tube structure and accessories 62 of Figures 5-7, it is noted that the sleeve 66 can be used with each of the other described embodiments or variations of the present invention. Figures 8 to 10 illustrate a tube and accessory structure 68 which is another variation of the tube and accessory structure 20 described above with respect to Figures 1 to 4, wherein like reference numerals are employed for like structures. The tube and accessory structure 68 is the same as that described above except that a recess 70 is provided that is deeper with respect to the previously described recess 32. The recess 70 is also dimensioned and located to receive the end of the tube 28 before deformation of the tube 28 by the jaws 46. As best illustrated in Figure 8, the tube 28 is initially placed on the front portion 24 of the fitting 22, with the end of the tube 28 extending within the recess 70 and against the packing 34 The method of assembly is the same as that described above, except that the relative longitudinal movement of the fitting 22 and the jaws 46 does not stop until the nose projections 48 of the jaws 46 are generally adjacent to the packing 32. As best illustrated in FIG. Figure 10, the deformation of the accessory 22 caused by this additional relative longitudinal movement causes the rear portion 26 of the accessory 26 to contract radially it turned inwardly against the tube 26. It has been found that the back portion 26 of the fitting 22 contracts radially inwardly in sealing engagement with the tube 28. Although the relatively deep recess 70 and the additional relative longitudinal movement are only described in detail with with respect to the tube structure and accessories 68 of Figures 8-10, it is noted that they can be employed with each of the other described embodiments or variations of the present invention. Figures 11 to 13 illustrate a tube and accessory structure 72 which is a variation of the tube and accessory structure 68 described above with respect to Figures 8 to 10, where like reference numerals are employed for a similar structure. The tube and accessory structure 72 is the same as described above except that at least one auxiliary seal member 74, 76 is provided before the accessory 72 and the tube 28. In the illustrated embodiment, a first auxiliary seal member 74 is locates between the outer surface of the tube 28 and the radially outer side of the recess 70 and a second auxiliary seal member 76 is located between the inner surface of the tube 28 and the outer surface of the front portion 24 of the accessory 22. Preferably, they form seats in the back portion 26 of the accessory 22 and the front portion 24 of the accessory 22 for the first and second auxiliary seal members 74, 76, respectively. Each auxiliary seal member 74, 76 is preferably an O-ring, but alternatively may be a flat, epoxy, seal or other suitable seal member. Seal members 74, 76 are preferably formed of a high temperature material such as, for example, silicone. The assembly method is the same as described above. As best illustrated in Figure 13, the first auxiliary seal member 74 is compressed when the relative longitudinal movement causes the rear portion 26 of the fitting 22 to contract radially inwardly against the tube 26 and the second auxiliary seal member 76 is compressed when the relative longitudinal movement causes the tube 28 contracts radially inwardly against the front portion 24 of the accessory 22. It has been found that the rear portion 26 of the accessory 22 and the tube 28, each contract radially inward, to compress the auxiliary seal members and form additional seals between the tube 28 and the accessory 22. Although the auxiliary seal members 74, 76 are only described with respect to the tube structure and accessories 72 of Figures 11 to 13, it is noted that they can be used with each of the other described embodiments or variations of the present invention. Although particular embodiments of the invention have been described in detail, it will be understood that the invention is not limited correspondingly in scope but includes all changes and modifications that fall within the spirit and terms of the appended claims.