US660221A - Manufacture of ordnance and projectiles. - Google Patents

Description

PatentedI Oct. 23, [900! J. A. P0TT`l ER. MANUFAGTUBE 0F ORDNANGE AND PBJECTILES.

(Apliction mea Apr. 15. 189s.)

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No. 66c,22|. Patented out. 23,19%.- A. POTTER.

MANUFACTURE 0F DRDNANCE AND PROJECTILESV.

(Application le Apr. 15. 189B.)

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v'UM'TED STATES f PATENT OFFICE.

JOHN A. POTTER, OE CLEVELAND, OHIO.

MANUFACTVURE OF ORDNANCE AND PROJECTILES.

S1"ECIIiI-GATIONY forming part of Letters Patent N o. 660,221, dated October 23, 1900.

Applcationviiled April 15, 1898. Serial No. 677,660. (No model.)

To all whom zit may concern:

Be it known that I, JOHN A. POTTER, of Cleveland, in the county of Cuyahoga and State of Ohio, have invented a new and useful Improvementin the Manufacture of Ordnance and Projectiles, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a sectional elevation of one form of press constructed in accordance with my invention. Fig. 2 is an enlarged partial seotion of another form, showing the plungers in depressed position. Fig. 3 is a horizontal section on the line III IlI'of Fig. 2; and Figs. 4, 5, and 6 are partial sectional elevations showing other forms of the press.

My invention relates to the manufactureof ordnance and projectiles, and isdesigned to' provide an improved method therefor, Whereby such articles may be cast without substantial piping or segregation in the interior of the casting.

To that end it consists in subjecting the molten metal to an end pressure until the outer shell is solidified, keeping the end portion hot and then subjecting the central end portion to a further pressure, thus preventing the iiuid interior portion from piping and from internal strains and segregation.

In the drawings, referring to the form of Figs. 1, 2, and 3, 2 represents a mold which is built up of interiitting steel plates, which are preferably water-cooled by pipes or channels 3 and which are bolted together by pins or bolts 4, extending through slots cut in the edges of the sections. These slots are so ar'- ranged that they register in alternate plates, the arrangement of the pins or bolts being clearly shown in Figs. 2 and 3. l show' the mold as resting upon a base 5, carried upon the plunger of a hydraulic ram 6,'carried centrally in the foundation of the machine and arranged to lift the base-plate from the roll-I ers 7 7, upon which the plate and mold are carried into position in the press. 8 8 are the side standards of the press, which form guides for a vertically-reciprocating cross-head 9, secured to the plunger 10 of a hydraulic cylinder 11. This plunger 10 -is hollow and cut out in its lower portion, so as to receive ya steel ring 17, adapted to contain a plug 18 of refractory material,this plug being of about the same diameter as the ram or rod 13. I provide at the sides of the cylinder 11 small lifting-cylinders 19, the rods of whose pistons are connected to the cross-head 9 .and serve to lift the same after the operation is completed. Fluid-pressure is admitted to the interior of the hollow ram 10 through a tubular `extension 20, extending through the top of its cylinder and secured to the ram, the fluid passing through a jointed pipe 21. The smaller ram 12 is lifted by a rod 22, extending upwardly through the tubular extension to a-piston 23 in an upper lifting-cylinder 24.

The operation is as follows: The mold, which has been suitably lined with a refractory material, as shown, being filled with molten steel iiuid pressure is admitted to the larger cylinder 11, thus forcing down the cross-head and pressure block and `subjecting the molten steel to a heavy hydraulic pressure. The inner ram 12 moves down with the plunger 10,

vremaining at the same point in the outer plunger during this operation. the outer shell of metal next to the mold has As soon as chilled so that the metal cannot be further compressed in its outer portions duid-pressure is admitted within the hollow plunger 10, thus forcing down the inner ram 13. This ram acting upon the refractory plug 18 forces this plug through the ring 17 into the central portion of the still liquid metal and subjects the same to a heavy pressure.- In order to prevent the plunger from entering and becoming embedded in the solidifying steel after it has forced down the refractory plug, it is-lifted sufficiently to allow the granular material inthe cavity ofl the pressure-block to feed down into the opening through the botloo tom of the block, and the ram 13 then being forced down again a'cts through this intermediate material upon the interior partiallycooled body of the metal. This operation is repeated as often as desirable. The ring 17 reduces the area upon which the smaller ram operates, and as the top of the ingot chills the ring becomes secured in place and fastened in and sustained by the castings and 1o sustains the intensified pressure upon the small ram and concentrates its power at the desired point. The gases will pass up into the cavity of the pressure-block and thence out through the filling-openings. The refrac- 15 tory plug being of non-conducting material tends to keep the central portion of the metal hot, and thus allows the compressive action of the inner plunger to be exerted thereon. Ihe central piping and segregation of thei 2o casting is thus prevented and an exceedingly y strong homogeneous metal is obtained throughout it. I may obtain this successive` pressure first upon the entire body of the` metal and then upon its inner hotter portion in many other Ways. Thus in Fig. l I show a single ram 25, having secured to its lower end a pressure-block l26, the lower part of which is reduced in` diameter and is surrounded by a series of rings or collars. The

3o lowermost ring 27 is provided with a centrali curved block 28, i of refractory material, against the central partof which the endl: of the pressure block abuts. Above this ring is an inner collar 29, surrounding the reduced portion of the block, and surrounding this collar are two rings 30, the lower of which. is composed of steel, while the upper is composed of zinc or some easily-fusible metal.` The upper face of the zinc ring is in the samef 4o plane as the top of the collar, and covering them both is an annular plate 3l of" steel, lz above which is an inner zinc ring 32 and outer zinc ring 33, the ring 33 being of less thick-` ness than the ring 32. When the ram is forced l down to bring the pressure upon" the molten i steel in the mold in this form, the block of l; refractory material will keep the central part a of the steel hot, and theheat being conducted .l from the metal upwardly :through the rings 5o and collars will gradually soften and `melt the zinc ring 30. The outer shell of the castl ing having cooled during the softening of this ring the whole `pressure of the ram is brought b upon the block and its collar 29, which bearing upon the refractory block will drive it;

down into the hotter metal and compress it. j

As the portions next to the outer shell con- ,1 geal, thus preventing further downwardI` movement of the collar, theheatvwill be cony oo ducted to the zinc rings 32 33, and these rings i will soften and melt, allowing the reduced part of the block to move down within the l1 collar 29 and act upon the central portion of l the molten metal. I am thus enabled to aui tomatically concentrate the pressure which l is first brought upon the entire body of molten metal upon its intermediate'and central por'- tions successively during the congealing of the casting, thus obtaining a solid compact metal.

In the form of Fig. 5 the rings 34 and 35, surrounding the reduced portion of the pressure bl`ocl above the collars 36 and 37, are of steel and are made in two or more parts, so that after the ram is depressed to bring the pressure upon the molten metal the plunger may be lifted and a portion of these rings removed, so as to allow the block and intermediate collar nt'o press upon Athe inner hotter portion of the metal, and when these are cooled it may be again raised and the inner rings removed, after which the plunger'is again de-` pressed, an'd the block sliding down within the collars acts upon the central part only of the cooling metal.

In the form of Fig. 6 I employ in place of the steel pressure-block a block 38 of wood, such a lignum-vitae, which may be provided in its lower face with a block of refractory materialand may be provided withencircling bands or hoops sunk in annular recesses to prevent crushing of the block. When this block is forced down into the steel, its portions around the refractory material will char and gradually burn away, so that the pressure will be applied to the central part of the molten metal, thus concentrating thepressure upon the hotter parts "of the metal, as in the previous forms.

I may carry out my process with ya plain solid steelblock of shape shown in Fig. 6, this block being secured to the lower end iof the plungerand fitting into the upper end of the mold-cavity by feeding in `granular material, such as hot sand, and forcing this material down upon the cooling metal. As the outer shell cools `more material is fed in and will be forced down in' the `central hotter portions, soas to concentrate the pressure thereon, as before- The advantages of my invention will be apparent to those skilled in `the art. Thecompressive force is exerted throughout the entire coolingA and solidifying of the steel, thus obviating the piping and internal strains heretofore caused by the contraction of the interior fluid metal after the `outer shell has solidied. The rapidvcooling of the article is hastened by the great pressure and consequent close contact of the metal with the mold, and a greater pressure maybe exerted upon lthe interior of the article thanfcould be "carriedmby the mold were it not for the solidified shell `surrounding the interior hot metal. The inner `part of the article is kept hot by the refractory plug or material, and the conipressive action may thus be prolonged upon `this part. The gases expelled from the steel `by the great pressure brought thereon will pass into the refractory lining and thence thro ughthe jointsbetweenthe mold-sections.

The invention is applicable also to the mak- IOO IIO

ing of ingots, shafts, and other castings, and I intend to cover the same when used upon any casting apparatus.

Many changes may be made in the form and arrangement of the press and in the means for applying pressure to the inner hotter portion of the metal as the outer parts chill and harden Without departing from my invention,

since What I claim isl. The method of making castings, consisting in subjecting molten metal in the mold to endwise pressure over a'major portion of its area, keeping the central end portion hot, and then compressing this central portion alone by further localized pressure after the har- JOHN A. POTTER.

Witnesses:

J. C. JONES, Jr., F. H. HART.

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