Page:Sheet Metal Drafting.djvu/150

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136
SHEET METAL DRAFTING

Problem 32
DRIPPING OR ROASTING PAN

60. Dripping or Roasting Pan.—Figure 186 is a sectional view of a standard dripping or roasting pan. Since pans of this kind are subjected to temperatures above that at which solder melts, it is necessary to employ some means besides soldering to enable them to hold liquids. This is accomplished by folding the corners of the pattern so that they will lie flat against the ends.

Standards of Construction.—All dripping pans have a standard flare of three-eighths of an inch as shown in Fig. 186. They are wired with No. 8 tinned or coppered wire. The measurements for this type of pan are always understood to be measurements of the top of the pan outside of the wire. The dimensions of the bottom are always 1¼ in. less than the measurements of the top. Thus, a 12 in.×18 in. dripping pan measures 12 in.×18 in. outside the wire around the top, and the bottom measures 10¾ in.×16¾ in. The depth varies with the size of the pans.

Pattern of One Corner.—Figure 187 shows a full size development of one corner of a dripping pan, which is produced in the following manner:

Draw the lines ab and bc forming an angle of 90°, Fig. 187.
Continue these lines indefinitely (shown by dotted lines bd and be), and set off upon these lines the slant height of the pan, bd of Fig. 187.
Draw lines dH and ek parallel to lines ba and bc, respectively.
Make lines df and eg three-eighths of an inch long.
Prolong these lines until they meet at the point L.
Draw the diagonal Lb.
With point f as a center, and any radius, draw the arc mnp.
With n as a center, set off the distance mn on the other side of the point n so that arc np will exactly equal arc nm.
Draw the line fg, extending it until it intersects the diagonal at the point r.
Draw the line rg.
Draw the lines sT and tu parallel to fr and rg, and at a distance of ⅛ in.

This cutting away of the corner allows the wire around the top