Зображення сторінки
PDF
ePub

quired length. This involved two separate forgings and two welds, and the smith had hard work to make this job pay at 61⁄2 pence, or 13 cents a piece. Later on, another firm took up this class of work and it was then run through in the following manner:

A set of cup-dies, to fit a bolt-heading machine, was made and fitted as shown in Fig. 1, as familiar to most of us. The block a is in two parts, and these are 3 inches apart when the machine is at rest. The heated ron is inserted against the face of fixed block b and up against a stop, not shown, which deter

Order issued

March-20-04 Material req'd soft Steel dia 100 long issued from stores in 300 lots.

B.I. 34

207

Heading die

Stamping

DIES

D 2.34

A Trinming

Shipped

April 7, 04

900

** 28

May 16

200

June 2

343

" 20

300

"

[blocks in formation]
[merged small][merged small][ocr errors][merged small][merged small]

414 TOTAL 3403

cost per plece 1

FIG. 273.-Time-card for

the forging-shop.

mines the length required to form
the head. The cam is engaged,
the die-block closes on the rod au-
tomatically, holding it tight, and
the moving head comes forward
and presses the rod into the die s,
forming a complete ball. These
dies are made of tool-steel and
hardened, the gripping surfaces be-
ing rough. When the furnace was
properly going, the fuel used being
oil, 60 heads per hour, or 30 rods
could be figured on. The rods
were heated for about six inches
along the end, and the operator,
who was a smith's helper, assisted

by a boy, made them to a length gage, the greatest allowable
error of which was inch either way, the length of the rods.
used being carefully determined beforehand by experiment.
These headed rods were next handled by the 300-pound
drop-stamp, and Fig. 2 shows the dies for stamping the eye,
and also how the lower half die is held on the hammer-base.
The corners of the gray-iron holder are cut away at an angle
of 60 degrees, so as to permit of a slight rotative adjustment,
the sides also have a slope upward so that the holder is held
against its seat by the adjusting screws. This is very conve-
nient for the operator in adjusting his dies, and helps to lessen.

1

1

the weight. The dies were made from tool-steel and carefully hardened so as to avoid leaving a curved surface. A groove,

inch deep and 3/4 inch broad, was milled all around the edges of the dies and 1⁄2 inch from it, as indicated at d. This was done to make sure the dies would come close together and also to provide a space for the "flash" or fin to flow into. These heads were brought to a welding heat in an oil furnace and stamped to a length gage.

MARCH 14,- 05

30 DROP

Name of piece

ORDER No. F.W.168

Tie-rod

[ocr errors]

Fig. 3 shows the trimming-die which sheared off the flash. This was made of tool-steel and given a taper of 3 degrees. It could not be fitted to the ordinary trimming-press owing to the length of the rod, so the trimming was done in the following manner. When the eye was stamped the operator's assistant placed the trimming-die, which was comparatively light to handle, on top of the lower half of the stamping-die and to one side. The eye was then placed

Index No.

Quantity

62

3018

Used on air brake for 4 wheel stock

FIG. 274.-Time-card for the forging-shop.

in position by the operator, and with a slight blow from the top the flash was sheared. With the eye still inside the die he pushed the trimming-die off the stamping-block, then, quickly turning the rod which he held in his hands, the trimming-die dropped off on to a plate placed to receive it, so that the eye passed completely through and came out at the bottom side of the die.

Great trouble was experienced in getting the centers of the tie-rods correct. Even with a rigid gage attached to the base of a drop-stamp which held one eye while the other was being stamped, the error would sometimes be as much as inch, and as the holes in the eyes were drilled at the same time to exact distance they appeared to be out of center with the eye. To overcome this the stamping-dies which were plain were discarded, and a new set was made with a centering dowel, as

[graphic]

FIG. 275.-Ten-thousand-ton hydraulic press.

shown at e, Fig. 2, which did away with the drilling jig and as the drill followed the stamped hole, as indicated at f, Fig. 4, the error, if any, appeared in the center to center distance and not in the eye. Owing to the saving of material by this method, the heading-dies were reduced from 134 to 15% inches, and the rods were cut 134 inches shorter, which on a large quantity meant a considerable saving.

Forging Without Special Tools

The tools shown in Figs. 6, 7, and 8 and also the numbered operations illustrate the very best method of making a similar tie-rod of short length under a steam-hammer by a skilled smith. The rod is made in one heat. The material is heated in the bar form and cut off; then, by means of swages, Fig. 6, it is roughed out as shown in operation 1. Next, one eye is formed, and then the other, by the repeated application of swages, Fig. 7, and the hammer itself. Then the finishing swages, Fig. 8, are used to bring the rod to correct length, the tails g g being cut off at an anvil. I have watched the piece made in this manner many times, and have seen a forging laid down complete before the color had left it. I have also watched this piece being made by the former method as described and the results were a reduction of 80 per cent. on the cost of production by the latter method. There were no special tools in the latter case, as the swages used are in everyday use for general work in the forge.

The skill of the smith has thus been replaced by means of tools which eliminate all inaccuracy, the necessary handling being done by the operators who are boys and smith's helpers. Figs. 273 and 274 illustrate a time-card for the forgingshop.

Ten Thousand Ton Press at the Dusseldorf Exhibition

The illustration (Fig. 275) shows a steam and hydraulic press, a model of which is exhibited in Dusseldorf, and the original of which exerts the trifling pressure of 10,000,000 kilograms, or 22,000,000 pounds. These presses, which are

made by the Kalker. Werkzeugmaschinenfabrik, are principally for forging and bending armor plates. There are three separate compressors and three separate ram-cylinders; and they are so connected that all three compressors act on all three press-cylinders, or any one or two thereof on all three cylinders. This enables the employment of the entire pressure of 10,000 tons, or of two-thirds or of one-third thereof, according to the need. The stroke is also widely adjustable at will. To give a slight idea of the dimensions of these presses (two such are at work in European shops) it may be said that the rear columns, which are each 17 meters in length, weighs 150 gross tons, and the three hydrauliccylinders, that together with the steel-plate between them make up the upper platen, as much more. The lower platen, which is built up, weighs about 400 gross tons. The platens are held to the columns by sixteen nuts, each of 1,200 mm. (47 inches) diameter, and whose united weight is about 50 gross tons.

« НазадПродовжити »