US2418874A

US2418874A - Apparatus for drawing flat metal blanks into shells

Info

Publication number: US2418874A
Application number: US540110A
Authority: US
Inventors: Jr Hartwell H Gary
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-06-13
Filing date: 1944-06-13
Publication date: 1947-04-15
Anticipated expiration: 1964-04-15

Description

April 15, 1947. H. H. GARY, JR 2,418,374

APPARATUS FOR DRAWING FLAT METAL BLANKS INTO SHELLS Filed June 13, 1944 INVENTOR, HarZwelZfi. Gary, 72:,

ATTORNEY.

Patented Apr. 15. 1941 PATENT oFncr:

APPARATUS FOR BLANK DRAWING FLAT METAL S INTO SHELLS Hartwell H. Gary, (in, Norfolk, Va.

Application June 13, 1944, Serial No. 540,110

- 1 Claim. 1

My invention relates to the plastic deformation of metals and more particularly to the deep drawing of fiat metal blanks into shells or cups, and it has for its object the development of a new and improved apparatus for producing deep drawn shells in fewer operations than has been possible under methods hitherto in use.

In order that there may be no misunderstanding as to the nomenclature used in the specification and in the subsequent claims, I shall refer to the work piece as it is received into the press, and whether or not it is flat or has been previously deformed, as the blank"; to that part of the work piece which has not entered the die as the flange; to that part of the work piece which has entered the die as the shell; and to the work piece as a whole, including the flange and the shell, as the work" or the "work Piece."

My new and improved apparatus provides a means of drawing in one operation and with one set of dies, a shell which is very deep as compared to its diameter.

Generally my apparatus involves the preliminary cooling of the center of the hot blank as the punch descends and forces the metal through the die and to continue cooling the metal adjacent the punch as it passes into and through the die.

It is well known that the resistance to deformation of metals, particularly ferrous metals,

varies according to their temperature. and that this resistance, both in tension and in compression of such metals, becomes less as the temperature increases above ordinary atmospheric temperature. It is the purpose of my invention to utilize this phenomenon to the end that the flange or perimeter portion of the work may be hot, making it easier to overcome the compressive resistance of the metal in thi portion and that the shell portion may be cooler and therefore possess greater tensile strength and be more able to resist the tensile strains which are set up in this portion.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment of the aforesaid objects and ends the invention still further resides in those novel method features and apparatus details of construction and operation, all of which will first be fully described in the following detailed description and then be specifically pointed out in the accompanying drawings in which:

Fig. 1 is a central vertical section and Part elevation of a hydraulic press adapted to carry out 5 my invention.

Fig. 2 is a plan view of the same. 1

Figs. 3 and 4 are schematic detail vertical sections showing respectively a shell about to be formed (Fig. 3) and a completed shell (Fig. 4).

In the drawings in which like numerals of reference indicate like parts in all the figures, i represents the bolster or stationary platen of a hydraulic punch press, 2 the movable platen, 3 the standards on which the movable platen slides up and down, 4 the passage through the stationary platen and 5 the punch. The die through which the metal of the heated blank 8 is drawn is indicated by the numeral 6 while I designates the blank holder, and ii represents the blank holder platen, I! the cylinders, l3 the pistons and it the piston rods for operating the blank holder.

The movable platen 2 with its punch is operated by hydraulic fluid. admitted and controlled in the usual way, via a port l5 in the cylinder i6, and acting on the piston ii that carries the platen 2. The blank holder cylinders I! with their platen and blank holder may be operated by compressed air or otherwise, or springs may 80 be substituted in place of cylinders for exerting I pressure on the blank holder. As the details of the punch press per se are well known further description thereof is unnecessary. While the drawings of my apparatus show a "down mov- 3 ing" press; that is, one with the cylinder at the top and its working stroke taking place in a downward direction, it is perfectly obvious that an up moving" press or even a horizontal or inclined press may be used.

In the embodiment illustrated the cooling of the metal takes place on its top face by means of .a coolant admitted into the space l8 through a. pipe '9 and withdrawn through a pipe I0 by a 45 suction pump (not shown).

From the foregoing description taken in connection with the accompanying drawings it is thought the construction of the apparatus. and the methods. employed will be clear to those 50 skilledinthe art.

What 1 claim ia: In apparatus-tor forming elongated shell: a stationary laten having a passage; a movable platen; a punch carried by themovable platen;

means for lowering and raising the movable 5 platen toward and from the stationary platen; a die on the stationary platen to receive a flat hot blank thereon; a blank holder over the die and having a passage for the punch; said blank holder having a central opening constituting a chamber whose bottom is constituted by the blank and through which the punch passes: and means for admitting acoolant to and withdrawing the same from said chamber for purposes described.

HARTWEIL H. GARY, Ja.

REFERENCES CITED The following references are of record in the file of this patent:

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