GB780889A - Improvements in or relating to the manufacture of tube elbows - Google Patents

Abstract

780,889. Making tube elbows; forging-dies; bending-dies; cores. HUET, A. June 9, 1955 [June 16, 1954; May 18, 1957], No. 16648/55. Classes 83 (2) and 83 (4). A method of making a tube elbow having a tubulure or pipe union on the outside bend of the elbow comprises compressing a heated elbow of bend radius greater than that of the elbow to be made by two dies which bring the legs of the elbow together and allow metal of the outside of the bend to be displaced to form a bulb which, if the outside of the bend has not previously been formed with an aperture, is then apertured to form a tubulure. An elbow a, filled with sand and heated over a zone A, Fig. 1, and, at a higher temperature over a zone B, and, if desired, at C and D, is held between parallel jaw b, c, Fig. 4. Dies d, e press the legs of the elbow together on to a die f, the metal of the outside of the bend being displaced through an opening h left between the dies to form a bulb g. The bulb is then apertured and finally shaped to form a tubulure. In a modification, Fig. 8, a circular aperture is formed in the outer part of the elbow prior to compression and a mandrel k is inserted in the aperture so that the displaced metal, on compression by the dies d, e, flows along the mandrel to form a tubulure l. In another modification, Fig. 10, an elbow a2 previously formed with a bulb m is compressed by dies d<SP>1</SP>, el, having faces inclined to the legs of the elbow to form an elongated bulb. An elbow having a previously apertured bulb may be bent with a mandrel in the aperture. The dies d<SP>1</SP>, e<SP>1</SP> may be hinged so as to straighten during compression to take up a position parallel to the legs of the elbow.