It frequently occurs that sheet metal reproductions of various emblems or tools are desired for use as ornaments or signs. In the following problem is shown how the various pieces necessary to form an anvil may be obtained. The description, of course, only applies to the several sides, as a representation of the horn can only be obtained by hammering or otherwise stretching the metal.
In Fig. 352 is shown a side and end elevation and two plans of the anvil, exclusive of the horn, the plans being duplicates and so placed as to correspond respectively with the side and the end views. Before the pattern of the side piece J N B G can be developed the line O P Q R S, which is the result of the miter-ing together of the two forms shown by U V W of the plan and Z X T of the end view, must be obtained. Therefore divide the curved portion Z XT of the profile of the side into any convenient number of equal spaces, as shown by the small figures, and from the points thus obtained drop lines vertically cutting W1 V1 U1, the profile of the gore piece. Transfer the points thus obtained on W1 V1 U1 to W V U of the other plan, and from these points erect lines vertically through the elevation of the side, and finally intersect them with lines of corresponding number drawn from the points originally assumed in Z T. Then a line traced through the points of intersection, as shown by O P Q E S, will be the required miter line.
To obtain the pattern of the side, first lay off a stretchout of the profile Z T, as shown, upon v q, through the points in which draw the usual measuring lines.
Fig. 353. - Patterns for the End Pieces of an Anvil.
With the T-square placed parallel with J G drop lines from the points in the profile Z T cutting the outlines of the side from J to a and G to 6, and also cutting the miter lines of the gore piece O Q S (which last operation has really been done in the raking operation above described). Placing the T-square parallel with v q, bring it successively against the points in the several miter lines of the side elevation and cut corresponding measuring lines; then lines traced through the points of intersection, as shown, from j to c, o to X, X to s and g to d, will give the pattern for the lower portion of the side. As that part of the side from Y to Z of the profile is straight and vertical, that portion of the pattern shown on the stretchout line from X to q can be made an exact duplicate of that part of the elevation shown by a M N B E b, all as shown.
Fig. 352. - Patterns for the Side, Gore Piece and Bottom of an Anvil.
For the pattern of the gore piece, U V Wis the profile and O Q and Q S are the miter lines. By means of the points previously obtained upon the profile in the raking operation, lay off a stretchout of the same upon any line running at right angles to the form of this piece, as shown upon U2 W2. As the points have already been dropped from the profile to the miter lines in the operation of obtaining them, it only remains to place the T-square parallel to U2 W2 and bring it suc-eessively against the points in O Q and Q S, cutting corresponding measuring lines; then lines traced through the points of intersection, as shown by U2 Q1 and Q1 W2, will give the pattern for the gore piece.
For the end pieces of the anvil, NMaKJ and B E b H G of the side elevation become the profiles, and Z T and Z1 T1 are the miter lines. Therefore, to obtain the pattern of either of these pieces, independently of the preceding operations, space the curved portion of its profile into any convenient number of spaces, and lav off a stretchout of the same upon any line at right angles to T T1. Carry lines from the profiles parallel to N B, cutting the miter lines, thence at right angles to T T1, cutting corresponding measuring lines. To avoid confusion of lines the operation of obtaining the patterns of the end pieces has been shown separately in Fig. 353, in which J N N1 J1 is an elevation of the front end and G B B1 G1 that of the back end. The points made rise of, however, upon their profiles, in Fig. 352, are such as were obtained there in cutting the pattern of the side; therefore their stretchouts must be transferred point by point to the stretchout lines; E D of Fig. 353 being the stretchout of N a J in Fig. 352 and B A of Fig. 353 being that of B b G. In consequence of the above the points upon the miter line Z T are such as were originally obtained there by spacing, and have been transferred to the lines N J, N1 J1, B G and B1 G1. The remainder of the work is shown sufficiently clear to need no further explanation.
PROBLEM 64. The Pattern for a Gable Cornice Mitering Upon an Inclined Roof.
In Fig. 354 let A B C G represent one side of the gable molding and NOM its profile. HBFF represents the horizontal molding, and D C the upper line of roof. The profile of this molding is shown by K L, and the inclined roof by K J. Before the pattern for gable can be described it will be necessary to obtain an elevation of the intersection of the gable cornice with the inclined roof between C and B to be used as the miter line.
The first step to be taken in obtaining this miter-line is to draw the profile of gable cornice, P Q R. directly over and in line with the profile of the horizontal molding J K L, as shown. Divide both profiles O M and P R into the same number of parts. From the points in O M draw lines parallel with the rake, extending them indefinitely in the direction of C B. From the points in P R drop lines upon the roof line J K, and from the points of intersection in J K carry lines horizontally across to the elevation, intersecting them with lines of corresponding number previously drawn from O M. Through the points of intersection trace a line, which will be at once the correct elevation of the miter and the miter line from which to obtain the pattern. If the pattern of gable at A G is required, in connection with that at the foot, extend the lines from points in M O to the miter line A G.
To obtain the pattern of A B C G, proceed as follows: At right angles to A B of gable lay out a stretchout of M O, as shown by S T, through the points in which draw the usual measuring lines. Place the T-square at right angles to the gable line A B, and, bringing it successively against the several points in A G and C B, cut corresponding measuring lines, all as indicated by the dotted lines.
Fig. 354. - Method of Obtaining Miter Line and Pattern for a Gable Cornice Mitering Upon an Inclined Roof.
Thus the line U X of pattern is of the same length as A B of elevation, and V W of pattern the same length as G C of elevation, etc. It is evident that the various lines in pattern are of the same length as. lines of corresponding number in elevation. Through the points obtained in the pattern trace lines as indicated by U V and W X. Then U V W X is the pattern for the part of gable shown by ABC G in elevation.