In Fig. 471, A C D B is the side elevation of the article and EFGMNOPR the plan. The corners are arcs of circles, being struck by centers H, L, T and S, as shown. Draw the plan in line with the elevation, so that the same parts in the different views shall correspond. Through the centers H and L of the plan by which the corners FG and M N are struck, draw F N indefinitely. Prolong the side line of the elevation C D until it cuts F N in the point K, as shown. Then K D is the radius of the inside line of the pattern of the curved part, and K C is the radius of the outside line.

Draw the straight line E1 F1 of Fig. 472, in length equal to the straight part of one side of the article, or E F of the plan. Through the points E1 and F1, at right angles to the line E1 F1, draw lines indefinitely, as shown by E1 U and F1 K1. Upon these lines set off, from F1 and E1, the distance K C, locating the points K1 and U, the centers for the curved parts. From K1, with the radius K C, strike the arc F1 G1, which in length make equal to F G of the plan. From G1 draw a line to the center K1, at right angles to which erect G1 M1, in length equal to G M of the plan. In like manner, with like radius, describe the arc E1 R1. Draw R1 U, at right right angles to it lay off O1 N1, equal to O N of the elevation. Draw N1 W, and draw the are N1 M2 in the angles to which erect R1 P1, equal to R P of the plan. At right angles to R1 P1 draw P1 V indefinitely. In the manner above described establish the center V, and from it describe the third arc P1 O1. Draw O1 V. At same manner as already described. In the same manner lay off the inner line of the pattern, as shown by m gfe r p o n m1 Join the ends M1 m and M2 m1, thus completing the pattern sought.

Fig. 471.   Plan and Elevation.

Fig. 471. - Plan and Elevation.

Fig. 472.   Pattern.

Fig. 472. - Pattern.

The Pattern of a Regular Flaring Oblong Article With Round Corners.