A hood with curved back, throat, and sides, as shown in Fig. 347, can have its patterns marked out with very little trouble if the method as shown on the diagram is followed.

For the cheek pattern, the lengths 0 1, 1 2, etc., are made equal in length to the arcs with the same numbers on the end elevation, and the width projected down from the side elevation, these points then being joined up. The curve a 4 at the top of the pattern will be the same as that on the elevation above. The back pattern lengths are taken from the side -elevation, lines drawn across, and these cut off to the required lengths by projecting down from the end elevation. The throat pattern is obtained by taking the lengths from the throat in the side elevation, and the widths across from the end elevation.

The four parts can be joined together by either knockingup, riveting, or any other method as required, the necessary allowances being put on the patterns.

Curved Square Hood 440

Fig. 347.