. Sheet metal workers' manual; a complete, practical instruction book on the sheet metal industry, machinery and tools, and related subjects, including the oxy-acetylen welding and cutting process . Figure 224.—Five-piece 60° Elbow. and mark this dimension on each end of the metal, asshown by ef. Then take the throat width or short side ofpiece No. 3, and place it as shown by fg. The length ofthe long side or top of piece No. 4 is placed on the metal,as shown by gh. Pattern L is now cut from the metal, after which themetal pattern is turned over and the curved edge placedon the points //. The
. Sheet metal workers' manual; a complete, practical instruction book on the sheet metal industry, machinery and tools, and related subjects, including the oxy-acetylen welding and cutting process . Figure 224.—Five-piece 60° Elbow. and mark this dimension on each end of the metal, asshown by ef. Then take the throat width or short side ofpiece No. 3, and place it as shown by fg. The length ofthe long side or top of piece No. 4 is placed on the metal,as shown by gh. Pattern L is now cut from the metal, after which themetal pattern is turned over and the curved edge placedon the points //. The irregular curve of the pattern is 278 SHEET METAL WORKERS MANUAL scribed on the metal by means of the scratch awl, whichcompletes the pattern for piece No. 2, shown at M. The patterns for pieces Nos. 3 and 4 are completed byplacing the curved edge of pattern L on the points gg;. Figure 225.—Elevation of Five-piece 60° Elbow. then scribe the irregular curve on the metal, and connectthe points hh with a straight line, completing the patternsN and 0. This method of grouping the patterns places the seams SHEET METAL WORK AND PATTERN DRAFTING 279 opposite each other, and allows the patterns to be cutfrom a rectangular piece of metal without waste of ma-terial. The patterns are now cut from the sheet, cornersnotched, rivet holes punched, formed in the forming ma-chine (Figures 35, 36) and riveted on the mandrel stake;after which the edges for seaming the pieces together areturned on the elbow edging machine (Figure 71). Five-Piece 60° Elbow.—Figure 224 shows a finishediive-piece elbow with an angle of 60°, such as would beused in ventilating and blow-pipe work, where it is de-sired to reduce the friction to the lowest possible amountby constructing an elbow having a long length of throat. In Figure 225 is shown the elevation of a 5-piece 60°elbow, the inner
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Keywords: ., bookcentury1900, bookdecade1910, bookidsheetmetalwo, bookyear1918
