US2913804A - One step cold nosing of shells - Google Patents

Description

Nov. 24, 1959 w. A. MARTIN ONE STEP com NosING 0F sHELLs Filed July 2, 1956 ZT/ KETNET Wayne A. Marijn wwf/1M, @w/@HUHE y 2,913,804 f oNE STEP COLD NosnvG or sHELLs Wayne A. Martin, Berkley, Mich., assignor to Lyon Incorporated, Detroit, Mich., a corporationl of Delaware Application July 2, 1956, Serial No. 595,540 6 Claims. (Cl. 29--1.21)

The present invention relates to the nosing of shells and more particularly concerns the nosing of drawn steel ordnance type shells. Inthe manufacture of large size steel shells by drawing from a sheet metal blank, the longitudinal shell wall between the base end portion of the shell and the nose end portion of the shell is relatively thin. This is especially true in low drag bomb head shells where the dimensions of one of the smaller sizes such as the 500 pound size is about a foot in diameter atthe largest diameter and about feet in length.` For larger sizes such dimensions are proportionately larger. Such a shell requires the longitudinal wall to be as thin as practicable consistent with functional compression and tensile requirements.

Certain cold workable steels are desirable since they enablerapid manufacture by cold drawing of the shells and thereby the attainment of highly uniform cross and longitudinal sections, grain structure, hardness and strength.

. In the nose extremity portion of a low drag bomb, for example, a substantial thickness of material is required not only to afford necessary mass for mounting tof' a fuse or tip but also to afford adequate impact jcompression resistance to dellection or buckling upon striking and penetrating a target. t

Because of the requirement for relatively large mass of material in the nose portion of the shell, nosing of the shell, that is working the nose end portion of the shell tothe desired taper or ogive presents a substantial problem. In addition to the radial compression and elongation forces required and the liability to distortion of the nose end portion mass incident to nosing, there is also a serious problem in the tendency of the longitudinal thin wall of the shell to buckle as nosing pressure is applied longitudinally of the shell.

Insofar as l am advised, it has been heretofore vconsidered impractical, if not impossible, to effect complete nosing of a steel shell with thickened nose terminus and thin longitudinal walls in anything but a plurality of successive nosing operations whether hot or cold work V techniques are employed.

According to the present invention, it is an important object to provide a new and improved method of cold nosing a steel shell completely in a single nosing operation, that is, in one pass or step in a nosing press.

Another object of the invention is to provide an im proved method of cold nosing steel shells in such a manner that after such nosing substantially uniform hard ness with the remainder of the cold worked shell is attained. j j -A further object of the invention is to provide an improved method of cold worked nosing of steel shells wherein a stepped center bore substantially free from buckling or non-uniformities is attained at completion of the nosing operation.

Still another object of the invention is to provide a novel, inexpensive, efficient method of nosing steel shells.

i United StatesA Patent() annealed.

ice A Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in connection with the accompanying drawing, in

which: y

Figure 1 is a fragmental longitudinal sectional view through a steel shell prior to nosing thereof;

Figure 2 is an enlarged fragmentary sectional longitudinal detail view through the nose portion of the shell of Figure l just before the same is cold nosed; and

Figure 3is a fragmental longitudinal sectional View through the shell after completion of the nosing thereof.

Preliminary vto the one step cold nosing of my invention, a flat or flattened steel blank is drawn into generally the shape of the shell desired both as to maximum diameter and generally the length of the shell desired minus the elongation accruing from the nosing operation. `A shell 5 at this preliminary stage in manufacture is shown in Figure l.. This comprises an elongated generally cylindrical longitudinal wall 7 of thin section provided at one end with a base 8 of substantial mass and with the lower end or 'base end portion of wall 7 and the base 8 back tapered as at 9. Although the back tapering 9 is shown in Figure 1 as provided before nosing, it will be understood that the back taper may be effected as an incident to nosing.

At its upper or nose or open end the shell 5 is provided with a thickened internal collar 10 of material which preferably merges on a generally curvingly tapered shoulder 11 with the inside diameter of the longitudinal or body wall 7 of the shell. Above the shoul.- der 11 the collar portion 19 is preferably provided with a tapered or flaring mouth providing a generally stepped arrangement including an inner tapered portion 12 and an outer counterbore-like offset narrower tapered portion 13. At the upper extremity of the collar portion 10 the tip of the shell is provided with an outside bevel 14 preferably about 10 to a plane, normal to the axis of the shell. At its inner margin the beveled tip 14 merges on a narrow inside bevel or chamfer 15 `with the offset outer mouth portion 13.

It has been found desirable in order to facilitate nosing to relieve the outer end portion of the collar 10 and this is effected by deepening the offset or counterbore groove portion 13 and affording a step or offsetting juncture 17 between the offset 13 and the beveled mouth portion 12 generally normal to the planes of the mouth portions 12 and 13 which are preferably parallel to one another.v p

Before nosing, the `internal collar portion 10 and a predetermined adjacent portion of the wall 7 is soft I have found best results to be obtained where the longitudinal wall 7 of the shell is left in work hardened condition resulting from drawing of the shell, while about the terminal or upper end V3 portion of the total length of the shell to be given the nose ogive is soft annealed at about 1250 F. where SAE 1030 steel is used. For example, where the ogived portion of the shell is approximately 27 inches about the upper or terminal 9 inches'of the shell is subjected to soft anneal- After the annealing the shell is cooled and is then preferably provided with a protective and lubricating coating such as afphoscoat.

Nosing of the shell 5 is elected by placing the shell in a nosing press including a nosing die formed with a nosing cavity of the nal shape yto be imparted to the shell nose. Nosing pressure is then applied longitudinally of the 4shell and the nose portion of the shell contracted in one step to the finished ogive shown in Figure 3. That is, the nose end portion of the shell is contracted and elongated from the full line condi- .Y 3 tion of Figure 2 to the dash outline condition, which is the form shown in Figure 3, in one continuous, uninterrupted application of pressure in the nosing press. It is important to keep the metal in the nose portion of the shell moving to completion of the nosing once the nosing pressure has been started.

I have found that although nosing, after preparation of the shell as described, is effected cold, the results attained are quite uniform. There is no buckling of the wall 7 of the shell nor is there any buckling or distortion of the entire ogived nose portion of the shell. Moreover, the originally flaring mouth end portions 12 and 13 remain in substantially parallel relation and attain a cylindrical condition with proportionate elongation. For example, where the length of the tapered mouth portion including both of the sections 12 and 13 is from 1%@ to 15/6 inch in the unnosed condition shown in full line-in Figure 2, there may be an elongation which results in an overall dimension of about 21/2 inches, wherein the respective sections 12 and 13 are proportionately elongated. The offset relief groove lportion 13 provides in the nosed shell a counterbore at the tip end of the shell. At the same time, due to radially inward displacement and inward tilting, the tip surface 14 which in the unnosed shell is beveled outwardly, assumes in the nosed condition of the shell a. slight inward bevel.

However, possibly the most unusual result attained by this one step cold nosing resides in that in the nosed shell the nose portion throughout shows a hardness that is substantially equal to the hardness in the longitudinal wall 7. In `a typical example, where the longitudinal wall tested from 99.5 to 103 on the Rockwell B hardness scale, the nose portion tested uniformly from 97 to 102 on the Rockwell B scale. Such uniformity in hardness rating throughout the length of a drawn steel shell is quite unusual. In fact by the one step cold nosing an improvement of about fourteen points in hardness has been effected over comparable examples of the shell employing three stage or step nosing.

It will be understood that modications` and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a method of making nosed shells from a cold workable metal, working the metal into the general shell form desired and providing a nose end portion of the shell with a collar of a larger mass of material than in the general longitudinal wall section of the shell, t

soft annealing said nose portion of the shell including said collar, forming a relief groove in the outer extremity portion of the inner diameter of said collar, and finally cold nosing the nose end portion of the shell by subjecting the same to longitudinal nosing compression uninterruptedly until the final nose ogive has been attained.

2. In a-method of making nosed shells from a cold workable metal, working the metal into the general shell form desired and providing a nose end portion of the shell with a collar of a larger mass of material than in the general longitudinal wall section of the shell, soft annealing about the extremity third of the nose portion of the shell that is to be ogived upon nosing and including said collar, forming a relief groove in the outer extremity portion of the inner diameter of said collar, and finally cold nosing the nose end portion of the shell by subjecting the same to longitudinal nosing compression uninterruptedly until the final nose ogive has been attained.

3. In a method of making nosed shells from a cold workable metal, working the metal into the general shell form desired and providing a nose end Portion f the shell with a collar of a larger mass of material than in the general longitudinal wall section of the shell, soft annealing said nose portion of the shell including said collar, forming an outwardly flaring wall relief groove at the inner side of the outer extremity portion of the collar, and finally cold nosing the nose end portion of the shell by subjecting the same to longitudinal nosing compression uninterruptedly until the final nose ogive has been attained and said relief groove wall has been contracted into substantially cylindrical shape.

4. In a method of making nosed shells from a cold workable metal, working the metal into the general shell form desired and providing a nose end portion of the shell with a collar of a larger mass of material than in the general longitudinal wall section of the shell, soft annealing about the extremity third of the nose portion of the shell that is to be ogived upon nosing and including said collar, forming stepped parallel flaring walls on the inner side of said collar and defining a relief groove at the inner side of the outer extremity portion of the collar, and finally cold nosing the nose end portion of the shell by subjecting the same to longitudinal nosing compression uninterruptedly until the final nose ogive has been attained and said walls have been contracted into substantially parallel cylindrical shape.

5. ln a method of making large size steel shells, drawing a cold workable steel piece into shell form having a thin cylindrical wall with an open mouth end portion provided with an internal collar of substantially greater mass than the section of the major `portion of said longitudinal wall, shaping said collar on its inner side with a beveled mouth with an offset pressure relief groove in the axially outer extremity portion thereof, soft annealing the nose portion of the shell including said collar while leaving the longitudinal side wall therebeyond in a work hardened condition, and nosing the nose portion by subjecting the same to axial ogiving compression in a nosing die by uninterruptedly continuing the nosing pressure and keeping the material in the nose portion of the shell moving until the ogiving has been completed and said beveled mouth has been moved to substantially cylindrical form inclusive of said relief groove thereby forming a counterbore at the tip of the nose.

6. In a method of making large size steel shells, drawing a cold workable steel piece into an elongated open mouth shell with a thin section longitudinal wall having at the mouth extremity of the shell an internal collarof substantially greater section and mass, grooving the inner side of said collar at the mouth extremity thereof, forming the tip of the shell wall and outer end of said collar with an outside lbevel, soft annealing a nose portion of the shell inclusive of said collar while leaving the longitudinal wall therebeyond in a hard worked condition, and in one step uninterruptedly nosing the nose portion of the shell including an adjacent portion of the longitudinal wall into final ogive by continuing the movement and working and elongation of the ogived nose portion from the beginning of nosing compression to completion of the nosing and until said groove provides a counterbore at the inner side of the tip of the nose and said outside tip bevel turns to an inside bevel.

References Cited in the file of this patent UNITED STATES PATENTS 2,357,110 Heineman Aug. 29, 1944 2,404,304 Layton July 16, 1946 2,515,841 Stuart .luly 18, 1950 2,736,085 Parre et al. Feb. 28, 1956 2,805,466 Lyon Sept. 10, 1957

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