In this case two stamping rings are made to suit the work at hand, as follows: If the dimension h is 2 inches and the thickness of the lever i is 1⁄2 inch, the rings must be made of 3⁄4-inch round stock, and welded to an inside diameter corresponding with the dimension k.
First draw the material to correspond exactly with the dimension k in one direction and somewhat greater than that of h in the opposite. The latter dimension is made larger, to provide some excess metal for the stamping operation, which is done in the following manner: Place one of the rings centrally on the bottom die of the hammer, as shown at B; lay the material on this, with the dimension h perpendicular and the proper distance from the end to provide enough metal for forming the lever and handle. Then place the other ring on top of the material directly above the lower one, and deliver blows on these rings until the entire thickness almost corresponds with the desired dimension h. The rings will be forced into the metal and form two depressions, as shown at C. Next with a hot cutter or trimming chisel remove the metal forming the corners e. Then draw out the lever portion roughly, at first; by using the taper tool a uniform taper can be produced correctly. Cut off the extra stock at the boss, and remove the surplus metal which projects between the bosses as indicated at d, and finish the end smoothly with a common top swage. The handle portion can be formed at the anvil with top and bottom swages after the end has been cut semicircular and to the desired length.
Fig. 124.—Steps in Making a Connecting Lever.
138. Connecting Lever.—A, [Fig. 124]. After drawing the metal to an appropriate dimension, fuller two depressions b on opposite sides, the proper distance from the end, to form the jaw. A single boss c should be stamped with one ring, at the required distance from b to provide the necessary amount of metal for the length d of the lever. Then remove the corners, as indicated by the broken lines. Begin drawing the lever by using the combination set, and finish the flat side with the hammer, producing the taper edge with the taper tool. Punch a square hole in the jaw and remove the metal indicated by the broken lines at e, with a hot cutter. Finish the jaw similar to the eccentric jaw and the boss as in the previous exercise.
Fig. 125.—Solid Forged Ring.
139. Solid Forged Ring.—[Fig. 125]. This should be made of soft steel, the dimensions being supplied by the instructor to suit the stock and equipment at hand. The volume (see calculating rules and tables, pp. [197]-206) of the forging must first be determined and some surplus allowance for forging provided. The process of making the ring will be found in the explanation of the use of the yoke in section [129].
Fig. 126.—Producing Double and Single Offsets.