US1494423A - Method of drawing metal shells - Google Patents

Description

May 20, 1924.

c. c. JESSEN METHOD OF DRAWING METAL SHELLS Filed July 28 1922 2 so i punch below the die.

Patented .May 20, 1924.

UNITED STATES 1,494,423 PATENT OFFICE.

CHARLES G.- JESSEN, Ol' WILMINGTON, DELAWARE, ASBIG-NOR. TO ATLAS POWDER COMP-ANY, OF wmumeromnnmwm, A CORPORATION OI DELAWARE mission or maawme METAL exams.

Application fled. July 28 1922. Serial K0. 578,098.

To all whom it may concern:

Be it known that CHARLES C. J ESSEN, citizen of the United States, residing at Wilmington, in the county of New Castle and State of Delaware, has invented certain new and useful Improvements in Methods of Drawing Metal Shells, of which the following is aspecification.

This invention relates to a method of drawing metal shells. The method constituting the subject matter of the resent invention is not limited to use in t e roduction of shells of any given kind since by this method a wide variety of articles may be manufactured. However for purposes of illustration I will describe it in con unction with the manufacture of the shells used in the manufacture of blasting caps or primers for the explosives commonly used in blasting and like work.

In making shells it is customary to start with a cup-like piece of metal and to elongate this and reduce it to the desired thicknes by successively forcing it through a number of dies by means of a punch, the thickness of the metal being reduced and the length of the shell being increased each time that it is forced through a die.- Heretofore the material of the shell after being forced through the die has been stripped from the punch upon upward movement of the punch by engagement of the upper end of the shell with the lower side of the die, thus causing the shell to drop from the Since in drawing shells it is necessary to subject them to a series of drawing operations in order to bring them to the desired length and thinness it follows that it is of advantage to have the shell stripped from the plunger above the die or work-table where they may be readily grasped and carried on to the next operation. Where the shells have been stripped from the plungers below the die they have ordinarily been caused to fall into suitable receptacles and must then be lifted above the work-table and brought into position to be operated upon by the succeeding die and plunger. Since, under conditions such as these, the o erator must select one shell after the other rom a number of shells,'q it follows that the amount ofwork that can be accomplished in a day is considerably less than would be the case where the shell is delivered above the work table ready for the operator to grasp it.

It is a primary object of the present invention to provide a method whereby the shell will be caused to adhere to the punch during the time that the punch is being returned through the die so that the shell will be carried back through the die with the punch, the shell being thereafter stripped as indicated at 10, and this cutting away or relieving of the lower part of this opening constitutes an important feature of the invention. The punch 8 travels through a stripper element 11 and upon upward 1110".8- ment of the punch 8 and shell 7 the upper end of the shell engages the lower end of the stripper element 11 and is stripped from the unch.

en the shell 7 is forced downwardly through the di 5 by the punch 8 the heat generated expands the metal of the shell at the drawing point but as soon as the shell leaves the die on its downward movement it shrinks onto the punch as it rapidly cools, with enough hold to allow the punch to pull it back through the die it was forced through, provided the die be relieved or rounded out, as indicated at 10. The shrinking of the shell onto the punch in this manner causes the shell to grip the punch so tightly that upon the upward movement of the punch the shell will be carried back through the die and it is in this method of shrinking the metal of the shell onto the punch that the present invention particularly resides since as a result of this I am able to avoid the ob'ections of those machines where the shell is stripped from the punch below the die.

Having described my invention what I claim is:

1. The herein described method which consists of forcing a shell entirely through a die by a punch of uniform diameter throughout its length to a considerable distunee below said die expanding the metal of the shell by the act of forcing the same through the die, the cooling of the metal of the shell as it passes below the die contracting the same upon the punch and then withdrawing the punch and shell through the die while the punch is gripped by the shell under such contraction.

2. The herein described method which consists of forcing a shell entirely through a die by a punch of uniform diameter throughout its length to a considerable distancebelow said die expanding the metal of the shell by the act of forcing the same through the die, the cooling of the metal of the shell as it passes below the die contracting the same upon the unch and then withdrawin the punch an shell throu h the die whi e the punch is gripped by t e shell under such contraction and thereafter ati-ripping the shell from the punch above the die opening formed therein provided with 'fiaring mouths both at its upper and lower edges in combination with a unch of uniform diameter throughout its operating length adapted to be, passed through said opening and to exert a drawing action upon a shell as it is forced through said 0 ening, the lowermost flaring mouth facilitating the entrance of the upper edge of the shell into said die upon upward movement of the plunger, said shell being held upon said I plunger by its contraction after being forced entirely through the die. In testimony whereof he aifixes his signature in the presence of two witnesses.

- CHARLES C. JESSEN.

Witnesses: FREDERIO Boomer, J r.-, JEAN MoGAUeHAN.

3: In combination a die plate having 'a p

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