Fig. 2976.
Fig. 2977.
Fig. 2978.
The upper half of the spoke is first blocked out under dies to the shape shown in [Fig. 2975], and the block b spread so as to form a section of the wheel rim, as shown in [Fig. 2976], in which d is a die, l a movable piece wedged up by the wedges w w, and removable to enable the extraction of the forging, and f is an end view of the fuller, the use of which is necessary to cause the metal to spread sufficiently in the direction of the dotted lines. The corners of the rim are then cut off, as shown in [Fig. 2973], and the rim is bent in a block having its top face of the necessary curve, as in [Fig. 2977], a being the block, and b a piece movable, to allow the extraction of the work, and fastened in place by the key or keys c. The two pieces are then welded together, their lengths, &c., being gauged by a sheet-iron template, formed as in [Fig. 2978]. The welding is usually performed with sledge-hammers, but as soon as the pieces will hold well together, the drawing down is done under a steam hammer.