US2415696A - Extrusion apparatus - Google Patents

Description

Feb. 11, 1947. w, KLOCKE v 2,415,696

EXTRUSION APPARATUS Filed oct.l 23, 194s zsneets-sne'er 1 y, TToRNEYs ExTRus 10N APPARATUS Filed oct. 23,. 1943 2 sheets-sheet. 2

GJM; @22% f ATTORNEYS Patented Feb. l1, 1947 2,415,6s`nsl EXTRUSION APPARATUS William Klocke, Woodhaven, N. Y., assignor to E. W. Bliss Company, Brooklyn, N. Y., a corporation oi' Delaware Application October 23, 1943, Serial No. 507,417

t This invention relates to improvements in eX- trusion apparatus and, more particularly, to apparatus in which a sleeve functions as a sliding die which confines a hot billet` laterally and slides telescopically relatively toa foriming die as the billet substance lis -moved with the sleeve 1 claim. (ci.v 20v-2) and pressed through the said forming die to give it a desired form, such as, for example, that of a rod, tube, rail, strip, or the like.

My United States Patent No. 2,167,845, granted August 1, 1939, discloses telescopically co-actingl sleeveandforming dies of the general character just mentioned and an extrusion method in`which the present invention may be employed; also mechanical die actuating means, including an air cylinder for actuating a sleeve die and a crank mechanism for actuating a cap for pressing billet metal toward and through a forming die, the said pressing cap, at the same time, serving to move the sleeve die, whereby to confine the billet metal against spreading laterally. The several die actuating means disclosed invsaid patent, or other suitable means, may be employed in practising the present invention and, hence, are not disclosed herein.

In forming metal and other substances into desired shapes, it is necessary to heat the substance to give it sufiicient plasticity to enable it Vto be extruded through a forming die. A substantial measure of the heat, of course,y passes into the sleeve die and the forming die, and, as the two said dies may be of different dimensions or composition, they may not expand uniformly; therefore, unless the two said dies are ing means which may conform to sealing surfaces uponeach of the two said dies in response .to a physical condition, such as heat or pressure which may be generated in the substance being extruded These and other objects are accomplished, inl general, according to the present invention, byV

the provision of an expansible sealing member, which may be in the form of a gasket or ring, having a first sealing surface adapted to engage a sealing surface at the input end of the forming die, a second sealing surface adapted to engage the interior surface of the sleeve die,` and a third surface, which, advantageously, may be a diagonal surface, adapted to receive an outwardly directed force `from the extrusion substance, for expanding'the sealing member so that its mentioned sealing surfaces eiect and maintain an electivesealing engagement with both the said dies to prevent extrusion substance from entering the'space between the two said dies.

For illustrative purposes only, and without limiting the invention thereto, the invention is shown in the accompanying drawings-in which Figs. 1, 2, and 3 are somewhat diagrammatic,

substantially central, vertical sectional views of the invention as employed to extrude metal with several dies, showing, respectively, the positions of the dies and the billet metal in first, intermediate, and final parts of a pressing portion of anextrusion cycle; y

erated by the friction of the metal passing over the die surfaces and further aggravated bythe lateral force exerted upon said dies by the billet substance during its extrusion.

The provision of a lloose telescopict between the sleeve and forming dies makes it necessary to provide simple and eiective means for p-reventing the substance being extruded from entering the clearance between the two dies, as, under the latter conditions, such substance itself would cause binding of the dies.

The principal object of the present invention is the provision of effective sealing means for sealing the clearance between the sleeve and forming dies, whereby to prevent ingress of billet metal or other substance into said clearance.

Fig.- 4 is a top plan view of a preferred form of sealing ring;

Fig. 5 is a cross-sectional view of said ring, on the line 5-5 of Fig. 4;

Fig. 6 is an enlarged detail of a portion of the structure as illustrated in Fig. 3, and

Fig. 7 isa View, somewhat similar to Fig. 5, of va, modified form of sealing ring.

Inasmuch vas the functioning of the sealing means, yielding the desired results, occurs during thev pressing portion of an extrusion cycle, Figs. 1, 2, and 3 should afford a clear general understanding of the invention. In these figures are shown a cylindricalfemale forming die Il,

fixed in upright position upon a bolster or bed I2, directly over an opening I2a provided in the latter t'o permit an extruded form to pass downwardly from said die through the saidbed. The die li is provided with an input opening Il denedbby an inwardly enlarged, annular, forming lip Il A cylindrical sleeve die i3 is adapted to be reciprocated vertically in loose telescopic relation- A further object is .the provision of such sealship to the forming die Il, by rods il which are fixed to the lower end of said sleevedie and extend downwardly therefrom through suitable4v openings in the bed I2.

The rods Il may be connected to suitable actuating means (not shown),V as, for example, an air actuated piston, as disclosed in my said patent, adapted to move the said rods and the sleevedie upwardly to bring the upper end of the latter into `engagement with the under-side of a pressing cap I5 which, with the sleeve die I3, defines a chamber It,

adapted to receive a suitably heated billet A '0f l metal to be extruded. 1

The pressing cap I5 may be reciprocated vertically by suitable means (notshown) acting" through a slide Il to the under-side of whichA the' cap I5 is fixed. In apparatus, as illustrated in the accompanying drawings. adapted to extrude metal into tubular form, the slide may be pro" vided with a chamber `I8 within which a plunger I! issuitably adapted to reciprocate and actuate a punch 2|), Vwhich is fixed to the1under-side 'of the plungerv I9 and extends throughlthel pressing cap I5 and is adapted, when moved downwardly, to pass through the billet metal into a central position within the forming lip of the "forming die where it functions as an internal die iny imparting atubular form to the extruded metal. l

The loose relationship-between the forming die I I and the sleeve' I3 is not apparent from Figs.

. `1, 2, and 3: but, in Fig. 6it maybe seen that thelsaid dies are so proportioned as to aiford a clearance 2| therebetween toy allow for unequal expansion of the two said dies. In order to seal `said clearance against the ingress of billet metal thereinto,an expansible sealing member 22, preferably'in the form of a metal ring of triangular crossfsection, is disposed upon the'upper end of 'the forming die ,and is adapted to expand 7 into sealingy and sliding sleeve die |11.

l engagement with the `as bestfseen in Figs. 5 and e the seaungrmg n,

` preferably,'has,a radial sealing surface 22', normalto a'circumferential sealing surface 22 of said`ring, Which surfaces respectively, are adapted `to eect a sealing engagement with an upper end'v surface ||.of theforming die and a sealing and, sliding engagement with the inside surface of the sleeve die, I2, The sealing surface 22, preferably, is of a substantial width, as shown in the drawings, to assure that the ring will. slide smoothly upon the inside surface of the sleeve die YI3: without scoring the latter surface. Also. byprovlding that the angle between thesurfaces l 22f-and 22h cf the sealing ring be identical with `tl'iefan'gle between the inside surface of the sleeve die I3 and the surface of the forming die |I, the sealing rlng22,funder the pressure encounteredin an extrusion"operation,` is forced and held "firmly within the angle between the two last-mentioned surfaces. Thus; the surface 22 isprevented from assuming any angularity with respect toftheinside surface of the sleeve die.

Because of this, the possibility of the latter surface becoming scored is obviated. The ring 22,

'preferablyns also provided with a diagonal surface 22` which faces inwardly and `upwardly and serves two chief purposes, to guide the billet metal 4 The ring 22 may be rendered expansible by splitting it, as by a straight out 22*i (Figs. 4 and 5), which preferably passes diagonally through a section of the ring. The diagonal extension of the cut 22d, as best seen in Fig. 5, may be considered as being helical with regard to the rins's axis. A diagonal cut, as Just described and illustrated, not only permits expansion of the ring, but functions to trap billet metal to prevent its passage through the ring into the clearance 2|. 'I'he split in the sealing ring, instead of being to trap and prevent passage of billet metall@ through the split. -In such a ring structure, the pressure of billet metal, passing through the ringwmay operate to press the split closed at the cut portion 221, or the angular splitmay function as let metal through the split.

Although the ring structures illustrated and ydescribed are preferred, the split may be effected, within the invention, by any Atype of cut which will render the sealing ring expansible, and. prevent material passage of billet metal through the split. Also, within the invention, the sealing ring, insteadof being split torender it. expansible, may be composed of material which. when subjected to the heator pressure of the billet metal, may become extended suiilcientlyzto yield the necessary expansion of the ring. The composition of the ring, also, may be so chosen as to yield a particular function; thus, it may be of a. metal adapted to lubricate `the billet metal as it is` constricted in its passage toward the forming die. or of 'a metal which mayv resist the heat encountered, whereby to assure its proper functioning for the duration of an extrusion cycle. The ring,ordinarily, is intended to be used only ina single extrusion cycle.

At. the beginning of an extrusion cycle, the I A sleeve die II is in its lowermost positionabout the forming die II, as shown in Fig. 3, -and the pressing cap II and the punch 20 are somewhat above their positions as shown in Fig. 1, thus leaving a clearance space above the forming die I The rst step. in the cycle is the placing of the ring 22 inposition'upon the top of the forming' die with the surface 22 facing inwardly and A upwardly, as shown in Fig'. 6. Then the hot metal billet A is placed'upon saidring, the sleeve die I3 is moved upwardly to surround the billet. and the pressing cap I5 is moved downwardly into l engagement with the upper end of thesleeve die.l

Then. with the parts in the positions substantially as shown in Fig. 1, the punch 20 is forced downwardly through the billet metal to its lowermost position relatively to the pressing cap I5,

bringing the lower end of the said punch to aposition within the input opening of thel forming die substantially as shown in Fig. 2, in which the billet metal displaced by the punch l 2B has been extruded into tubular form', as at 65 Thereafter the punch 2|) and the pressing cap I5 are forced downwardly together, to positions sub-y stantially asshown in Fig. 3, pressing most of the plete tubular form, as at AAA; the sleeve I3, meanwhile. being forced downwardly by the cap 5 and serving to conne the billet metal against lateral deformation.

It will be understood that, during thev downward ilow of the billet metal, the latteris under pressure which exerts a force upon the diagonal effected by a straight cut, as Just described,`may have portions 22, 22, and 22' (Fig. 7) which are angular Vto eachV other` and which may function a labyrinth, eifectually preventing passage of bil- I billet metal through the forming die into coinf surface 22 of the ring 22 substantially in the directions indicated by arrows in Figs. 1 and 6, thus operating to expand the said ring outwardly into a firm sealing and sliding engagement with the inner wall of the sleeve die i3, and to press the' said ring downwardly and hold it down into firm sealing engagement with the top surface Ilc of the forming die il. Thus the ring 22 serves as a very eiective means for sealing the clearance 2i against the entry of billet metal thereinto and permits use of the disclosed telescoping die arrangement with its attendant advantages.

After completion of the extrusion of a billet of metal, as hereinbefore described, the several dies may be moved to open positions and the ring 22, together with the adjacent unextruded flashmetal remaining above the forming die II, may be cu-t off in any suitable manner. A new sealing ring may then be inserted in position, as already described, as a preliminary step in a succeeding extrusion cycle.

The present invention, although described and illustrated with reference to the extruding of metal into a tubular form, may be employed in extruding other materials and for producing rods, as disclosed in my mentioned patent, or producing other forms by extrusion.

Inasmuch as the invention may be practiced in ways other than those illustrated and described or mentioned herein, it is not to be considered as limited except as dened'in the following claim.

What I claim is:

In extrusion apparatus, the combination of a die member having an axially extending extrusion aperture and a substantially radially-extending surface at the input end of said aperture; a sleeve member substantially surrounding said die member and being telescopically reciprocable relatively thereto and partially deninga variable-volume billet chamber, the said sleeve memtber having a cylindrical inner surface and sumcient clearance between the latter surface and an adjacent outer surface of the said die member to permit expansion and contraction of said mem- -bers which may modify said clearance without material resultant binding of said members; and

le of this patent:

iii means for diverting billet material in said billet chamber from said clearance andA for guiding such material toward said extrusion aperture, the said means comprising an expansible sealing ring which is substantially non-deformable in radial cross-sectionLand has an outer cylindrical Afirst sealing surface of substantial width in substantially intimate face to face relation with said cylindrical inner surface of the sleeve member, a second sealing surface extending radially inwardly substantially from oneside of said first sealing surface, acrossl said clearance, and into substantially intimate face to face and parallel relation with respect to the mentioned radiallyextending surface of said die member, and a billet-engaging surface within and extending at least partially across the angle formed by the mentioned rst and second sealing surfaces, the said billet-engaging surface being substantially open to the interior of said billet chamber where- 'by to receive pressure directly from a billet in said chamber to forcibly expand said ring into sealing engagement with said cylindrical inner surface of the sleeve member and to urge said ring into. sealing engagement with said radiallyextending surface of said die member whereby to divert billet material from said clearance` and guide it toward said aperture.

WILLIAM- KLOCKE.

REFERENCES crrxmE The following references are of record in the UNITED STATES PATENTs Number Name Date 2,021 Hanson Mar. 29, 1841 493,945 Robertson Mar. 2l, 1893 165,386 Tracy July 6, 1875 571,265 Dick Nov. 10, 1896 2,167,845 Klocke Aug. 1, 1939 `2,033,735 Pack Mar. 10, 1936 Re. 82 Ranson Mar. 14, 1846 FOREIGN PATENTS Number Country Date British 24,9480 Nov. 6, 1906

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