US2958116A - Method of and means for tapering shells - Google Patents

Description

Nov. 1, 1960 G. A. LYON METHOD OF AND MEANS FOR TAPERING SHELLS s sheets-sne'z 1 Filed June 16, 1954 3 FE I1 I13 T Gearye A beri Lyon 4M vgwm flm v Nov. 1, 1960 e. A. LYON 2,958,116

METHOD OF AND MEANS FOR TAPERING SHELLS Filed June 16, 1954 a Sheets-Sheet 2 Pic-6L2 E7 IE 7:: Z a T George A/berz L 5 012 Nov. l, 1960 G. A. LYON 2,958,116

METHOD OF AND MEANS FOR TAPERING SHELLS Filed June 16, 1954 5 Sheets-Sheet 3 E7215. TIZQT Gggrye A/blf LyQ Z W, y Z 1775 METHOD 013 AND MEANS FOR TA'PERING SHELLS George Albert Lyon, 13881 W. Chicago, Blvd., Detroit 28, Mich.

Filed June 16, W54, Ser. No. 437,250

Claims. (Cl. 29-121) The present invention relates to the tapering of ordnance shells such as bomb head and art-illary shells.

In the manufacture of ordnance shells, and more particularly in the larger sizes of such shells, such as may be used as the nose components of' bombs of the low drag type which are transported to and dropped upon targets by bombing planes, tapering of not only the nose ends of the shells but also of the base end portions of the shells presents substantial problems. One such problem arises from the necessarily thin wall throughout the major extent of the shells, so that caving-in buckling or collapsing of the thin wall incident to a nosing or backtapering operation must be avoided. A second problem that arises concerns the necessarily heavy or substantial base wall structure of the shell resisting compression or contraction as an incident to the back-tapering operation.

It is therefore an important object of the present invention to provide improvements not only in the method but also in the apparatus for nosing and back-tapering shells, and particularly applicable to large size shells such as thin wall bomb head shells.

Another object of the invention is to provide an improved method of back-tapering bomb head shells wherein a substantial collar of material must be provided at the base end of the shell for subsequent heading or machining for reception of other bomb components.

A further object of the invention is to provide improved apparatus for efiectuating the method of the present invention.

Still another object of the invention is to provide for the back-tapering of ordnance shells following tapernosing of the shells.

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 conjunction with the accompanying drawings, in which:

Figure 1 is a more or less schematic vertical sectional view through a nosing die apparatus showing the same in operative relation to a shell taper nosed thereby;

Figure 2 is an enlarged vertical sectional view through the nosed shell showing how a core member utilized interiorly of the shell during the nosing operation, is re moved therefrom;

Figure 3 is a vertical sectional view through a more or less schematically illustrated back-tapering apparatus, showing the nosed shell associated therewith in preparation for back-tapering of the shell; and

Figure 4 is a view similar to Figure 3 but showing the apparatus following completion of the back-tapering operation upon the shell. 7

According to the present invention, a shell that has, for example, .been drawn into elongated cylindrical shape with an open upper end and a closed lower or base end is first nose-tapered and subsequently back-tapered. During both of the tapering operations, the elongated thin tubular side wall of the shell is supported against buckling distortion. Since the nose-tapering involves a subt nt ov- 1, 9 0

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stantial length of the upper end portion of the shell, the side wall is supported not only externally of the shell but also internally of the shell. During the back-tapering operation, the lower end portion involvement in the backtapering is moderate and substantially less than the nosetapering involvement of the shell side wall, and since there is little likelihood of inward buckling or caving of the side wall, merely external support is supplied for the shell wall. During the back-tapering, moreover, substantial strain upon the side wall of the shell is avoided by relieving the compression resistance of the shell base by removal of the major portion of the base wall of the shell so as to leave but a limited annular collar of the base wall material.

Having reference to Figure l, a shell 5 having a thin tubular cylindrical wall 7 and a substantially thicker lower end or base wall 8, is open at its upper end and is adapted to be nose-tapered throughout a substantial extent of the upper end portion of the wall 7, as shown at Nosing of the shell 5 is effected prior to backtapering.

Nosing apparatus 10 may be utilized to accomplish nosing of the upper or open end portion of the shell 5. To this end, the apparatus 10 comprises a base portion or supporting block 11 having a cavity 11a opening upwardly therein and complementary to the cylindrical lower end or base portion of the shell 5. When the base portion of the shell 5 is seated within the cavity 11:: the major portion of the shell projects upwardly above the supporting block 11. Within a reduced diameter downwardly opening extension of the cavity bore 11a, is accommodated a stripper or ejector plunger 12 having an operating rod 13 working through a base plate or block 14 upon which the supporting block 11 is mounted and against which the stripper 12 rests solidly in the inactive position wherein the upper end of the stripper provides a solid bottom wall for the cavity 11a.

cooperatively related to the shell supporting base block 11, in relatively vertically reciprocable fashion is a nosing die block 15 having therein a nosing cavity 17 opening downwardly and shaped to provide the symmetrical tapered contour desired in the finished nose of the shell. A head plate or block 18 supports the nosing die 15 and may be mounted upon or operatively carried in association with the ram of a suitable press. Nosing of the shell 5 is effected by driving the nosing die 15 axially toward the base block 11 with the shell 5 disposed co- :axially within the supporting cavity 11a.

For lubricating the nosing cavity 17 during the nosing operation so as to facilitate operation of the die and to reduce frictional losses and heating incident to the nosing action of the die, means are provided for supplying the nosing cavity 17 with a coolant and lubricating fluid. Accordingly, a hydraulic fluid supply duct 19 is secured into the top of the plate 18 concentrically relative to the nosing cavity 17 to discharge thereinto. A packing 26 secured in place by gland nut 21 secures the end of the duct 19 against leakage thereby. When the nosing die 15 is brought into shell nosing relation to the shell 5, hydraulic fluid, preferably comprising a lubricating oil or at least having lubricating qualities, is introduced through the duct 19 into the nosing cavity 17 and into the shell under pressure so as to positively tend to leak past the shell downwardly through the nosing cavity. As the nosing operation progresses, the nosing die 15 may be successively backed off from the shell 5 and returned to the nosing engagement therewith so that as contraction of the nose portion 9 of the shell progresses the lubricant will be worked in the successive backing off and nosing pressure stages in the operation between the outer surface of the nose portion 9 on the shell and the nosing cavity wall. During this, pressure of the hydraulic fluid is preferably maintained high enough to have an ejecting or stripping action on the shell when the nosing die 15 is backed off. As a safety measure, the duct 19 is provided with a relief valve 22 which may be mounted in a branch exhaust or spill-off duct 23 leading from the main hydraulic supply duct 19.

To promote lubricating leakby of hydraulic fluid between the shell and the nosing die cavity, a suitable series of leakby or metering orifices 24 may be provided through the wall of the die 15 leading from the cavity 17 to the exterior of the nosing die. Hydraulic fluid that leaks from the nosing die and after the nosing operation spills therefrom is received in a container or sump 25 supported by the base block or plate 14 and surrounding the die assembly to a suitable height.

Means are provided for supporting the thin shell wall 7 not only against inward buckling or caving but also against outward buckling or distortion during the severe axial thrust imposed upon the shell wall incident to the nosing operation. For internal support, a body of a suitable low melting point, malleable material such as lead is filled into the shell 9 to a height adequate for affording internal anti-buckling support for the shell wall 7, as indicated at 27. For reducing the volume of lead required for this purpose, a filler core member 28 is provided which may comprise a solid cylindrical elongated member of appropriately smaller diameter than the inside diameter of the shell wall 7 and of a length approximately as long as the extent of the shell wall requiring internal support. This mandrel or core member 28 is provided with a downwardly directed small diameter base stem 29 which is engageable in a central complementary bore 30 in the base wall 8 of the shell. After the core member 28 has been introduced into the unnosed shell 5, the lead body 27 in molten condition is poured into the shell and engages solidly against the thin shell wall 7 to support the same.

External support for the shell wall 7 during nosing is rovided by an annular series of narrow spaced upstanding fingers 31 on the base block 11 cooperating with complementary downwardly projecting annular series of similar supporting fingers 32 on the nosing die block 15. In operation, the fingers 31 and 32 mesh fairly closely slidably to provide a substantially solid annular supporting ring about the approximately midsection of the shell side wall 7. Support against possible radially outward spreading of the retaining fingers 31 and 32 is afforded by an annular ferrule or sleeve 33 which is carried by the nosing die 15 and encircles the retaining fingers 32. Fluid pressure relief through the ferrule 33 is afforded by vent ports or orifices 34 therethrough at the base ends of the spaces between the fingers 32 which accommodate the upstanding fingers 31 in operation.

Following completion of the nose tapering of the shell 5, the internal anti-buckling core 28 is, of course, trapped inside the shell cavity. For releasing the core 28, therefore, the lead body 27 is melted out by heating the nosed shell and pouring the lead out of the constricted nose opening in the shell. The core 28 will then drop away from the base Wall 8 in the inverted position of the shell 5. Then the central portion of the base wall 8 is cut out to provide an opening 35 (Figure 2) somewhat larger than the diameter of the core 28 and the core member 28 can then be removed from the nosed shell as by dropping it out through the opening 35. The internal collar of material left after the cutting of the opening 35 provides a ring of material integral with the base end of the shell wall 7 sufficient for subsequent machining and use in attachment of other components of a projectile assembly such as a bomb assembly.

By removal of the substantial material in providing the base hole 35 and thereby substantially reducing resistance to radially inward compression of the remainder of the base wall 8, back-tapering of the shell 5 is substantially facilitated. Such back-tapering is accomplished A. in a back-tapering die assembly 40 (Figures 3 and 4). This die assembly includes an upper vertically reciprocably operable driving block member 41 and a lower back-tapering die block member 42 operatively related thereto.

A head member such as a plate 43 carries the driving block 41 and is adapted to be mounted upon or carried as a part of a press ram (not shown). For engaging the nose portion 9 of the shell 5, the driving block 41 is provided with a downwardly opening axially disposed cavity 44 complementary to the generally ogival nose taper shape of the nose portion 9 of the shell and with the lower end portion of the shell 5 to be back-tapered projecting an ample distance below the lower end portion of the driving block. It will be understood, of course, that the internal dimension of the cavity 44 will be such as to accommodate the shell nose portion 9 without substantial binding. However, in order to enable positive stripping or kickout of the shell from the cavity 44, a kickout or stripper plunger 45 is mounted reciprocably in the head plate 43 and the upper end portion of the cavity 44 to engage the nose tip of the shell 44 to dislodge the shell from the cavity 44 should it stick therein following the back-tapering operation.

Support for the back-tapering die 42 is provided by a base member or plate or block 47 upon which the block 42 is mounted fixedly. It will be understood that the base plate 47 is adapted to be mounted upon a press bed or anvil so that the back-tapering die 42 will be supported rigidly in operation to withstand the substantial down ward thrust thereupon during the back-tapering operation.

Opening upwardly from the back-tapering die member 42 is a back-tapering cavity 48 having the wall thereof shaped to the desired final tapered shape of the base end portion of the shell 5. Thus, when the shell 5 is driven base end down into the back-taper cavity 48 by axial compression force exerted by the driving block 41, the base end portion of the shell working against the tapered cavity wall 48 will be contracted uniformly radially inwardly to the desired shape.

Within a downward extension of the cavity 48, is reciprocably mounted a stripper plunger 49 resting normally at its lower end against the base plate 47 and pro viding the bottom or stop wall defining the back-tapering cavity 48. For reciprocating the stripper plunger 49, it may be provided with a downwardly extending operating rod 50 projecting through the base plate 47. In other words, when the back-tapering operation has been completed, the stripper plunger 49 is operated to move upwardly in the back-tapering cavity 48 to eject the backtapered shell therefrom.

In order to facilitate the back-tapering operation within the cavity 48, a lubricant bath is maintained about and within the back-tapering die block 42 as by means of a container or sump 51 extending about and to a suitable height above the back-tapering die, and a body of suitable lubricating fluid 52 is maintained in the container 51. Communication between the back-tapering cavity 48 and the interior of the container or sump 51 for free interflow of the lubricant is provided for by ports 53 extending through the wall of the die block 42. These ports 53 must necessarily be small so as to avoid interfering with proper wiping compression of the base end portion of the shell and therefore a substantial number of the ports 53 is provided. As herein shown, a plurality of annular series of such ports is provided. Thus, as the shell 5 is driven down into the back-tapering cavity 48, a maximum supply of lubricant fluid therein assists in the back-tapering operation by reducing friction between the surface of the shell and the surface of the cavity 48 to a minimum. During such back-tapering operation, the shell may be backed out and rammed down into the back-tapering cavity 48 several times as the base end portion is gradually contracted to the back-tapered shape. The ports 52 therefor enable free flow of the lubricating fluid into and out of the cavity 48. Some of the lubricating fluid may, of course, be accommodated inside the base portion of the shell 5 as seen in Figure 4, in the final phase of the back-tapering operation. Therefore, although most of the fluid may be displaced from the cavity 48, any undesirable pressure of the fluid is avoided.

In order to avoid possible outward buckling of the thin wall 7 of the shell between the base end portion that is to be back-tapered and the nose portion 9 of the shell during the back-tapering operation, cooperatively related means are provided on the adjacent end portions of the driving block 41 and the back-tapering die block 42 to afford lateral support for the shell wall 7. To this end, the driving block 41 is provided with a depending skirt portion 54 which engages about the thin shell wall adjacent the nose 9, and the die 42 is provided with an upstanding collar 55 above the back-tapering cavity 48 to support the wall 7 above portion being back tapered. As the drive block 41 drives downwardly to ram the shell 5 into the back-tapering cavity 48, the encircling portions 54 and 55 firmly support the thin side wall 7 of the shell against outward buckling.

It will be appreciated, of course, that by the substantial reduction in the material of the base wall 8 of the shell prior to the back-tapering operation, contraction of the base end portion of the shell is substantially facilitated. During the back-tapering contraction of the base of the shell and thus reduction in both inside and outside diameters of the remaining portion of the shell base wall 8, the thickening of such base wall portion is useful in providing an adequate annular collar or mass of material for subsequent machining preparatory to assembly of the base end portion of the shell with other components of the projectile unit.

It will be understood that modifications 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 nose-tapering and back-tapering an originally cylindrical shell having a closed base wall, filling a rore and a solidifiable mass of malleable low melting point metal into the shell adjacent to the base portion and along the inside of the sidewall of the shell, supporting the shell in a rigid base support and nosetapering the shell while afiording external support for the side wall in cooperation with the internal support therefor, after the nose-tapering melting out said low melting point metal, cutting out a central portion of the base wall of the shell and removing the core, and thereafter back-tapering the base portion of the shell.

2. In apparatus for back-tapering shells, a driving member having a shell nose receiving cavity therein, and a back-tapering member having a back-tapering cavity therein into which the base portion of a shell is driven by the driving member, said driving member and said back-tapering cavity member having cooperating means thereon for supporting the side wall of the shell against buckling.

3. In apparatus for back-tapering shells, a shell driving ram member having a shell nose cavity therein for receiving the nose portion of a shell to be back-tapered, a back-tapering die having a back-tapering cavity into which the base portion of a shell is adapted to be driven by said ram member, and means for maintaining a lubricating bath within the back-tapering cavity.

4. In apparatus for back-tapering shells, a shell dr'i ing ram member having a shell nose cavity therein for receiving the nose portion of a shell to be back-tapered, a back-tapering die having a back-tapering cavity into which the base portion of a shell is adapted to be driven by said ram member, and means for maintaining a lubricating bath within the back-tapering cavity, said means comprising a container about the back-tapering die member and the die member having openings therefrom through which lubricant fluid is adapted to flow from a body of the fluid within the container about the die member.

5. A method of making a large size thin walled elongated ordnance shell comprising the steps of supporting a cylinder open at one end and having a base wall at its other end on its base wall and along its outer wall for a portion of the length thereof, partially filling the cylinder with a low melting point internal metal filler having a cylindrical wall engaging the inner wall of the cylinder for a portion of the length thereof, contracting the open upper end of the shell into tapered nose form, then cutting out a portion of the base and removing the filler by melting, and then back-tapering the shell while supporting its outer wall against buckling.

References Cited in the file of this patent UNITED STATES PATENTS 772,940 Humphrey Oct. 25, 1904 887,950 Lindenborg May 19, 1908 1,016,507 Lewis Feb. 6, 1912 1,286,384 Mezger. Dec. 12, 1918 1,773,741 MoNiff Aug. 26, 1930 1,891,304 Everett Dec. 20, 1932 2,202,042 Blount May 28, 1940 2,387,692 Sundstrom Oct. 23, 1945 2,404,304 Layton July 16, 1946 2,407,855 Stephens Sept. 17, 1946 2,522,915 Woods Sept. 19, 1950 2,688,297 Livermont et al. Sept. 7, 1954 2,735,389 Wurzburger Feb. 21, 1956 FOREIGN PATENTS 2,466 Great Britain Jan. 31, 1884

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