Metal working – Method of mechanical manufacture – Assembling or joining
Patent
1998-05-04
2000-04-18
Bryant, David P.
Metal working
Method of mechanical manufacture
Assembling or joining
29516, 292835, 2853822, B21D 3900, B23P 1100
Patent
active
060499621
DESCRIPTION:
BRIEF SUMMARY
The invention concerns a method for joining a pipe with a press fitting that has a cylindrical section and, at each end, a radially outwardly projecting annular bead which has, toward the free end of the press fitting, a bead shoulder directed radially inward and on the inside forms an annular groove into which a sealing ring is placed, such that to produce the joint, the press fitting and pipe are slid one into another and then the annular bead and the cylindrical section are pressed radially inward accompanied by plastic deformation of the pipe as well. The invention further refers to a combination of press fitting, pipe, and pressing device for carrying out said method, the press fitting and pipe being slid one into another and the press fitting having a cylindrical section and, at each end, an annular bead projecting radially outward and having, toward the free end, a bead shoulder directed radially inward and a sealing ring which is placed on the inside into the annular groove there; and the pressing device having multiple pressing jaws with an internal pressing contour which constitutes a pressing region, running in the circumferential direction, for acting upon the annular bead, and a pressing land running at a distance therefrom and projecting radially inward. Lastly, the invention is directed toward a pressing device of the aforesaid kind.
For the joining of pipes, it is known to use sleeve-shaped press fittings which are made of metal, preferably of steel. In order to produce the pipe joint, the press fittings are slid over the pipe end and then compressed radially, both the press fitting and the pipe being plastically deformed.
DE-C-1 187 870 discloses a press fitting which has a cylindrical section and is equipped at each end with an annular bead which projects radially outward. On the inside, the two annular beads form annular grooves into which a sealing ring is placed. The annular beads each terminate, toward the free end, in a bead shoulder oriented radially inward, which is pointed at the inner edge like a blade. With this press fitting, the inside diameter of the cylindrical section in the unpressed state is somewhat greater than the outside diameter of the pipes to be joined. The diameter of the cutting edges of the bead shoulders is--again in the unpressed state--less than the inside diameter of the cylindrical section in one case, and in the other case is identical to it. In both cases, radial pressing takes place in such a way that the respective cutting edge is pushed into the relevant pipe, forming a constriction with plastic deformation. The cylindrical section of the press fittings is compressed only to the point that its inner surface comes into contact against the outer surface of the pipe, without deforming the pipe.
This type of joint between pipe end and press fitting has proven disadvantageous for several reasons. Pushing the cutting edges into the pipe end regions results in the creation of high notch stresses in the pipe end regions, which can lead to breaks in this region and thus to leaks. Moreover, the joint is not suitable for higher pressures. In addition, sealing is jeopardized by the sealing rings, since the pipe regions located opposite the sealing rings are moved away from the sealing rings by the constrictions, thus reducing sealing areas.
A transition has recently been made to press fittings such as those indicated by EP-B-0 361 630, DE-A-40 25 317, U.S. Pat. No. 5,007,667, and DE-U-92 16 369.6. They have a cylindrical section which is constricted in the center region, so that stops for the pipe ends are formed there on the inside. In the respective regions adjacent thereto on the outside, the cylindrical section has, in the unpressed state, an inside diameter which is slightly greater than the outside diameter of the pipes to be joined, so that tolerances can be compensated for. The annular beads on the ends of the press fitting have oblique bead flanks, proceeding from the cylindrical section, which transition into curved sections and then into the bead should
REFERENCES:
patent: 3149861 (1964-09-01), Larsson
patent: 3803897 (1974-04-01), Ridenour et al.
patent: 4371199 (1983-02-01), Kushner et al.
patent: 5007667 (1991-04-01), Unewisse et al.
patent: 5121625 (1992-06-01), Unewisse et al.
patent: 5148698 (1992-09-01), Dischler
patent: 5150519 (1992-09-01), Unewisse
patent: 5484174 (1996-01-01), Gotoh et al.
German Patent Appl. No. 9216369 U, Mar. 18, 1983.
Brochure Regarding the Viegener Profipress Press-Fitting, Date Unknown, 13 pages.
Bryant David P.
Cozart Jermie E.
Novopress GmbH Pressen und Presswerkzeuge & Co. KG
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