to the shape shown and hardened at the bending face. The locater O and the spring arrangement are self-explanatory. The die also is of tool steel and is machined to fit the bolster and has a tapped hole at W for fastening screw. P P indicate the blank in position for forming, while the dotted lines V V indicate it as formed into the die. SS are the side gauges and T the end locating point. In use, the press in which the dies were located was inclined, and the work after bending fell off at the back.

For the last operation in the production of Fig. 491 the very simple tools illustrated in Fig. 494 were used. The work before finishing is indicated by the dark portion O 0 in position on the

The

locater I, while the dotted lines P P show it as finished. punch, of tool steel, is machined to fit the dovetailed channel in the face of the holder (not shown) and at II to fit the central formed section of the work; the die is of cast iron.

The rapidity with which these two bending dies can be worked and the quality of the work done by them are surprising when the simplicity and cheapness of the tools are considered. Some may think that it would have been better to have designed a die which would do all the bending in one operation. Possibly, if a sufficient quantity of the articles were required-say several millions.

"GANG" PUNCH AND DIE FOR PRODUCING
EYELETS IN ONE OPERATION.

As an example of what is being accomplished in the devising of means for the production of sheet-metal articles in one operation I illustrate and describe here a "gang" die of very interesting type. A number of these dies were designed and put into successful operation by the writer not long ago for the produc

tion of one of two parts of a metallic button. They will be found the best to adopt for the manufacture of small buttons, eyelets, shell rivets, and anything of like nature that it is necessary to produce cheaply and in large quantities. To secure the minimum cost of operation, the stock is usually fed automatically by means of a fine-tooth ratchet roll-feed, thus securing fine adjustment of the stroke.

In brass work, where we can get our stock in long lengths, or in rolls approximately uniform in width, a die of the type shown in Fig. 495 will run off the entire strip or roll without the

possibility of error, thus allowing of the press attendant looking after several presses and keeping them running continually.

Now, in the first place, be it understood that in order to draw sheet metal into any form or shape, it is first necessary to provide a blank. And when the article drawn is produced progres

B

H

FIG. 496.

sively, as in the die here shown, it is necessary, first, to cut the blank partly from the strip so that it may decrease in diameter with the drawing in such a manner as in no way to disturb the relative distance between the centres of the different operations required to produce the shell. This is the point which many die-makers forget, so that the dies prove defective where means are not provided for first partly cutting the blank, and there is no possibility of locating the successive operations in their proper positions, because of the metal which goes to form the cup being drawn sidewise and lengthwise in the first drawing. And as this will continue with each draw, there will be no likeli hood of accurately locating the different operations. The way in which a "gang" die of this kind should be made in order to attain the desired results, will become apparent to the practical reader in the description of the tools here shown.

The punch and die were used to produce small shells like the one shown at the upper right of Fig. 495. And it required seven workings to produce the shell, finishing it complete from flat stock at the rate of 40,000 to 50,000 per day of ten hours. The stock used was .030 soft brass.

As the illustrations of the die and punch show clearly the various parts used in the construction of the tools, and Fig. 496 the results accomplished at each operation in the progress of the strip across the die face, very little description will be necessary.

The stock is first cut as indicated at 4, Fig. 496, by punch J, Fig. 495, and then at B by punch K. Thus, the blank is produced so as to remain attached to the strip and to allow of being drawn and decreased in diameter by the subsequent operations

without affecting the position of its centre in relation to the strip. This will allow of the metal being drawn into the shell and still leave a margin to hold the cups together and allow of feeding them along for the next operation.

The stems of the seven punches J K L M N O and Pare let into reamed holes in the holder I and are fastened with set-screws, not shown. The punches were all hardened, drawn, and carefully lapped to size and shape. The die is finished in the usual manner, formed counterbores being used to finish the drawing and sizing dies. Q is the first cutting die, R the second, S the first drawing die, T the second, U the third, and V the sizing and finishing drawing die, while W is the blanking and trimming die. Each of the drawing dies is furnished with a plunger, which is hardened and drawn and let into pad Y. These plungers serve the double purpose of holding the metal while being drawn and of stripping it from the dies afterward, thereby leaving the stock free to be fed forward to receive the next operation. A channel planed lengthwise in the bolster A-A at Z allows the pad Y to work up and down with the action of the press ram. The two springs B-B B-B keep the plungers up with sufficient tension to hold the metal securely between their faces and the faces of the drawing punches while the drawing and reducing are being accomplished. Their pressure is adjusted or regulated by the headless screws D-D D-D. The trimming or blanking punch P has a pilot pin which fits the last drawing snugly and locates it true and central for being trimmed and blanked clean off the strip.

As the results accomplished by the use of such tools as are herein described and illustrated would require three or more operations if the simpler tools were used, it is no hard matter to figure out what the saving is.

In conclusion I might state that there is any variety of small drawn, formed, or embossed sheet metal work that could be produced more accurately and in half the time by the use of just such dies as that shown here. In order to succeed with these tools, however, always remember, before attempting to draw and form cups progressively from the strip, to provide means for partly cutting the blanks from which to draw the cups.

COMPOUND DIES FOR PARTS OF TELEPHONE
TRANSMITTER CASES.

In Fig. 497 are shown the assembled parts of a telephone transmitter case of sheet metal, and in Figs. 498 to 503 the dies used for producing the parts. It is needless to state that these cases are used in great quantities and that the dies for their production are required to be of the most accurate and lasting construction in order that the parts may be produced rapidly and in exact duplication. As the work involved in the production of the Part transmitter-case parts consists of blanking, drawing, forming, piercing, and wiring, the dies are interesting, and engravings of them, together with the description of their construction and operation,

FIG. 497.

will prove suggestive in the adoption of similar tools for the production of a large variety of drawn sheet-metal work, accurately and economically.

As will be seen from Fig. 497, the case consists of three parts, designated 1, 2, and 3, respectively. The part 1 is of an artistic shape and represents a nice job in drawn work. The die used for producing it is shown in Fig. 498 and was, as were all the blanking and drawing dies used in the production of the case parts, of the compound double-action type of construction. a great many tool-makers are not familiar with drawing dies of, this type, a slight description of their use will contribute to an intelligent understanding of their making.

As

Double-action dies derive their name from the fact that they are used in double-action presses to cut a blank and at the same stroke draw it into shape without the help of springs or buffers, as in the case combination single-action dies. The kind and thickness of the metal used determine whether one or several operations will be necessary to obtain the desired shape and