US2003438A - Tool for making cartridge shells - Google Patents

Description

, June 4', 1 935. A. GUIGNET TOOL FOR MAKING CARTRIDGE SHELLS Original Filed March 1. 193s 2 Sheets-Sheet l Inventor Z, co/v Ill/ 05 Guignet' June 4, 1935.

| A. GUIGNET TOOL FOR MAKING CARTRIDGE SHELLS Original Filed March 1, 1933 2 Sheets-Sheet 2 fitta r71 ey.

Patented June 4, 1935 UNITED STATES PATENT OFFICE TOOL FOR MAKING CARTRIDGE SHELLS Lon Auguste Gnignet, La Varenne Ste. Hilaire,

France, assignor to Asturienne des Mines, tion of Belgium The Compagnie Royale Paris, France, a corpora- Original application March 1, 1933, Serial No.

659,115, now Patent No. 1,974,270, dated September 18, 1934. Divided and this application September 9, 1933, Serial No. 688,760. In Germany January 17, 193

3 Claims fold in the shell between the base and the tubular part of the shell, the crowns of said. fold having a relatively large radius of curvature so as to readily withstand the internal gas pressure upon firing.

The present invention has for its object a tool for manufacturing shells of this character.

Another object is to provide a tool by which said shells can be manufactured expeditiously and with a minimum number of operations.

Other objects and advantages will hereinafter appear.

The accompanying drawings illustrate, by way of example, a constructional embodiment of the new tool and its operation.

In the drawings Figure 1 is a longitudinal cross section of the lower part of a completed shell having a relatively thick bottom portion and a relatively thin side portion of substantially uniform cross section.

Fig. 2 is a longitudinal section of an intermediate form of a shell during its manufacture and prior to its insertion in the present tool for the finishing operation.

- Fig. 3 is a longitudinal section of the tool while the shell blank illustrated in Fig. 2 is being inserted.

Fig. 4 is a longitudinal sectionof the tool at the end of the forming operation of the completed shell.

Fig. 5 is a detaiLcross section of parts 6, 6 on line 55 in Fig. 3, looking in the direction of the arrows Referring to the drawings, the same illustrate a tool for the final conversion of a unitary shell blank as illustrated in Fig. 2 into a completed cartridge shell as illustrated in Fig. 1, said shell having a tubular side wall I of either constant or of tapered cross section'which is merged into a base 2 of preferably greater thickness than the wall I through a double fold consisting of an outer convolution 4 and an inner convolution 5, the cross section of the connection between the convolution 4 and a bottom rim 3 being preferably tapered and the crowns of both convolutions of tne fold having a; substantial radius in cross section so as not to cause overstraining oi the material during formation and when subjected to internal. pressure upon firing.

The tool consists of two portions, the upper portion A being preferably arranged for mounting on the rain of a drawing or punching press, while the lower portion B is preferably arranged for fastening to the stationary platen of the press.

The portion A is provided with a longitudinalconical central bore adapted to receive a frustated conical liner 6 which is radially divided into two halves as indicated by' Fig. 5. The liner is provided with a central bore l9 approximately corresponding to the outside diameter of the shell blank. Arranged inside of said bore is a mandril I, having a collar 20, said mandril being fixedly attached to the body of the part A.. The axial length of the liner 6 is slightly less than the corresponding bore in the body A'so as to provide a space I! between the upper end of the liner and vthe collar 20, said collar being recessed in the body A so as to form an abutment for the mandril 1 and also for the liner 6 so as to limit the lateral movement of the latter with respect to the body A. Y V

The lower end of the mandril 'l is provided with a bevel H of such shape as to aid in the formation of the inner fold or convolution 5 of the. shell. The mandril 1 has a central bore in which is slidably mounted an ejector pin 9, the upper part of said ejector pin being provided with a I collar which limits its downward movement. The

ejectorpin is urged downwardly by a spring 8. The diameter of the mandril I is such as to correspond to the inside diameter of the shell, thus providing fora space between themandril and the liner for the introduction of a shell blank as illustrated in' Figs. 2 and 3. A recess I0 is provided at the lower end of the bore IQ of the liner 6 of such shape as to facilitate the formation of the outside fold or convolution of the shell. In the downward direction the liner is prevented from sliding out of the body A by means of a collar l8 having a bore 18 of suitable diameter.

The lower part B of the tool is provided with an annular flange or ring I which is slidably guided in said body by means of a number of rods I5. The upward movement of said flange is limited by a number of screws II. The rods list their lower free end abut against a-colllar it which is urged upwardly by means of a heavy spring l3. In a central bore of the flange H is slidably mounted a plunger l2, said plunger being fixedly attached to the body B. The bore I8 of the upper part of the tool is of such diameter as to pass the upper end of the flange I4 and permit it to bear against the liner 5.

The shell consists of a tubular part I and a raise u 2. The blank is first drawn in the usual manner, the bottom having a constant thickness which may be greater than that of the tubular part and the wall of the tubular part may be slightly ta;- pered or may be straight. It will be understood that the portions shownin Figs. 1 and 2 are somewhat exaggerated. As an example, the thickness of the top end of the tubular part may be .23 mm., while the thickness of the tubular part near the base may be .3 mm., and the constant thickness of the base may also be .3 mm., or may have a thickness of as much as .7 mm., the latter proportion approximately corresponding to th proportion shown in paragraph 1. The tool-operates in the following manner: After the shell blank I is inserted in the upper part A of the tool as illustrated in Fig. 3, the ram of the press is lowered and the upper part A moved towards the lower part B. The shell is pushed into the recess l9 approximately to the point where its base 2 abuts against the ejector pin 9. Approximately at the same time the flange l4 touches the lower surface of the liner 6 so that upon further downward movement the flange is urged downward against the pressure of the spring l3. As this spring pressure is relatively high, it resists the downward movement of the flange and causes movement of the liner longitudinally in the part A and thus causes the latter to close in radially on the tubular part of the shell I so as to press it tightly against the mandril I and prevent it from further upward movement. The liner slides in the part A until the air gap I! has been closed, whereupon its turther longitudinal movement is prevented by abutment against the collar 20. Upon further movement of the part A, the spring I3 is compressed by the downward movement of the flange H and ultimately the shell blank makes contact with the plunger I2. This plunger thereupon drives the material of the shell upwardly and causes it to fold, said folding being guided by the recesses l0 in the liner 6 and the bevel ll of the mandril I. The bore Ill also determines the outside diameter of the shell rim. The relative position of the tools is ultimately as illustrated in Fig. 4 in which the shell has its final shape. Thereafter the ram of the machine is raised and the parts A and B separate again. This movement finally releases the upward pressure on the liner 6 and the latter opens up radially and permits the shell to be ejected from the part A by the action of the spring 8 on the ejector pin 9, the spring having been previously compressed by the upward movement ofi the base of the shell and of the ejector pin 9 after contact of the base with the plunger l2.

The described apparatus produces a shell from a blank in a single operation instead of a number of complicated and difiicult operations required by other known means. It further assures a shell,

the material of which has not been subjectedto manufacture of other types of shells than the one herein illustrated and described and I therefore do not wish to limit the appended claims to a tool for manufacturing the shell illustrated herein.

What I claim as new and desire to secure by Letters Patent is:

' 1. A tool for the production of a double fold between the bottom and the side of a unitary cartridge shell, comprising an upper part, said upper part comprising a mandril for said shell, having a beveled lower end adapted to produce the inner convolution of said fold upon application-of an axial thrust upon said shell, a divided liner shaped andadapted to move radially to grip said shell and having a recess adapted to produce the outer convolution of said told upon application of said thrust, and a lower part, the latter comprising a fixed plunger, a relatively movable flange surrounding said plunger, and

adapted'to engage said liner to cause it to move laterally and a biasing spring tending to oppose movement of said flange. I

2. A tool for, the production of a double fold between the bottom and the side of a unitary cartridge shell, comprising an upper part, said upper part comprising a mandril for said shell havinga beveled lower end adapted to produce the inner convolution of said fold, a spring biased element concentric with said mandril tending to push said shell out of engagement therewith, a divided liner shaped and adapted to move radially to grip said shell and having a recess adapted to produce the outer convolution of said fold, and a lower part, the latter comprising a fixed plunger, a relatively movable flange surrounding said plunger, and adapted to engage said liner to cause it to move laterally and a biasing spring tending to oppose movement of said flange.

3. A tool for the production of a double fold between the bottom and the side of a unitary cartridge shell, comprising an upper part, said upper part comprising a mandril for said shell, having a beveled lower end adapted to produce the inner convolutions of said told upon application of an axial thrust upon said shell, a spring biased element concentric with said mandril LEON AUGUS'I'E GUIGNET.

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