US3080962A - Die drawing of clad rod or wire - Google Patents

Description

March 12, 1963 E. FLEISCHMANN ETAL 3,080,962

I DIE DRAWING OF cum ROD 0R WIRE Filed June 12, 1959 INVENTORS Ernst Fleischmonn 8 Leslie 0. Whitne %M@ drawing thereof.

United States Patent 3,080,962 DIE DRAWING F CLAD ROD 0R WIRE Ernst Flcischmann, Clairton, and Leslie C. Whitney,

Forest Hills, Pa, assiguors to Copperweld Steel Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed June 12, 1959, Ser. No. 819,971 2 Claims. (Cl. 205-16) This invention relates to apparatus and method for reducing the diameter of clad rods and wires by the die More particularly, this invention pertains to dry die drawing of aluminum clad steel rod and wire at practicable production speeds.

The instant invention'make practical the dry die drawing of clad rod and wire such as Alumoweld aluminum clad steel rod and wire at production speeds without scratching, scoring or gelling the cladding surface and without stripping or upsetting such cladding and with concurrent reduction of cladding and core despite the thickness of cladding and its relative softness and Weakness when compared with the core as in the case of such aluminum clad rod and wire, such as that producible by the system disclosed in United States patent application Serial No. 773,125 filed June 16, 1958.

-Other objects, features and advantages of thi inven- .tion will be apparent from the following description and of FIGURE 3; and

FIGURE 5 is a view in section taken along line V-V of FIGURE 4 to illustrate a section through a triple die embodiment of this invention.

Referring to the drawings, a machine is provided with a trunnioned die holder 11, a die assembly embodiment 12 of this invention for dry die drawing of a clad rod or wire 13 such as the aluminum clad steel rod or wire named above and a capstan 14 having wraps of the reduced rod or wire 13a therearound for traction and cooling. In the illustration, the machine is a so-ealled onehole machine and the wraps on capstan 14 as it revolves move up onto coiling posts 15 from which the coil of reduced wire 13a is periodically removed. The wraps on capstan 14- may, instead, be conducted through one or more further die drawing stations or holes in continuous succession for the reduction thereof in successive stages utilizing conventional automatic multihole wire drawing equipment.

Die holder 11 is pivotally supported about horizontal pivots 16 by brackets 16a and comprises an open-top box with a cleamout opening in the bottom thereof normally closed by a pipe plug 17. The front of the box is pro vided with an axial opening 18 in which a guide disc 19 may be seated. Disc 19 may be made of a material like nylon with a central opening 20 therethrough for the rod or wire 13, hereinafter called wire, which is pulled in the direction of arrow 21 by the rotation of capstan 14 at a selected linear speed by power means (not shown) for machine 10. The capstan 14- is preferably cooled interiorly by water or otherwise and air blasts may be provided around its exterior to sweep its wraps of drawn Wire to cool said wire, particularly when the cladding may be a relatively soft metal like aluminum.

At the front of die holder- 11 there is a generally 'U-shaped die clamp 22 bolted thereto. Clamp 22 is provided with vertical guide grooves 23 opposed to one anice other and a swingable locking strap 24 to be closed to lock a die base 25 in place after it has been slid into place in holder 11, the base 25 being provided with vertical side projections which fit in grooves 23. Base 25 is provided with a drilled and tapped opening 26 in which die assembly 12 is rigidly fixed in coaxial position relative to the axis of the path of movement of the wire, which is reduced when it is drawn through die assembly 12. The reduced wire 13a moves on through opening 27 in die holder 11 and engages capstan 14 initially at the bottom of the tier of wraps therearound.

Die assembly 12 in the illustrated embodiment comprised a hollow die mount 28 having a threaded end 29 which screws tightly into the opening 26 in base 25 to rigidly hold the mount without movement during die drawing operations. The other end 30 of mount 28 is also threaded for engagement by an annular retainer nut 31. Further, a boss 32 around the middle of mount 28 has its exterior surfaces in the form of a square for engagement by 'a spanner wrench whenever mount 28 is to be inserted into, or removed from, base 25. Mount 28 is provided with an axial circular bore 33 communicating at the exit end thereof with a smaller diameter opening 34 coaxial with opening 27, the axis and direction of movement of the clad wire therethrough being represented by the arrows 35.

Die assembly 12 utilizes a front or entrance die 36, an intermediate die 37, which dies 36 and 37 act as pressure dams, and a reduction or drawing die 38, although the device of this invention is operative also with but one pres sure dam die and one drawing die. Each die has an outside cylindrical surface which slidably and closely fits in bore 33. In addition, the front face of die 36 projects enough to engage the opposed face of nut 31 to clamp the dies in the mount 28. Such faces are preferably provided with a fine true finish in the mating plane at 39, as is the case also at the rear plane 40 defined by the rear face of reduction die 38 and the bot-tom of bore 33 around opening 34. The directly opposed adjoining faces between each pair of dies are provided with annular grooves'41 which 'have a very superiorfinish to engage the flat faces, with like superior finishes, of sealing rings '42 which may be made of hardened steel, or other sealing means may be provided between the dies so that the pass-age therethrough and through openings 43 in sealing rings constitutes an elongated high pressure space pursuant to which continuous, cold, dry-die drawing is obtainable on clad Wire without impairment of the relation between cladding and core and with proportionate reduction of such cladding and core, even though such two metals may be greatly dissimilar in their respective properties.

In a die drawing operation of this invention, an aluminum clad rod 13 moving toward die assembly 12 is dabbed or wiped with a carrier, such as castor oil or a suitable dag, to provide some surface tackiness. It

may be done manually or from a dabber supply 44 with a rotating wiper 45, or the wiping may be continuous with preferably a sparing application of such carrier material. The wire 13 then passes into the box of die holder 11 and receives a coating of finely powdered conventional soap lubricant represented by a chain line 46 (FIGURE 4), which is compatible with the cladding metal on the clad wire being drawn, before entering a wide angle opening 47 through the center of retainer nut 31. The width of opening 47 and the comparatively short length of die 36 facilitate the feeding of clad wire 13 from a coil into assembly 12 without previous straightening. The clad wire 13 is of a diameter which is somewhat less than the diameter of the bearing 48 of die 36 where central opening 49 through that die is at its narrowest. The same relation exists between the outside diameter of clad rod 13 and bearing 50 of die 37 except that the clearance for the clad wire in bearing 50 preferably is somewhat less. As a consequence, considerable pressure appears to build up in the central space between bearing 48 and passage 51 in the intermediate die 37 with perhaps a still greater pressure between bearing 50 and the approach angle 53 of reduction die 38 which promotes, in the manner of an extrusion effect, the drawing of aluminum cladding so that it takes place in accordance with the elongation of the core while the clad wire is being drawn, without scoring, stripping or upsetting of that aluminum cladding by bearing 54 in the reduction die 38. In the initiation of such an operation, the leading end of the clad rod to be drawn is pointed by tapering of at least the cladding in the direction of intended movement for several inches to facilitate the commencement of such a die drawing operation. As the composite wire passes through the die box, the conventional soap lubricant adheres to the surface of the clad wire. The continuous carrying of soap lubricant into the die assembly builds up a very high pressure in this assembly until the quantity of lubricant brought into the die passages substantially equals the amount of lubricant leaving tungsten carbide reduction die 38 generally in the form of a very thin close coating continuous along and around the reduced wire 13:: which gives it a relatively dark matte finish appearance in the case of aluminum clad steel. Successive such die reduc tion steps may be performed, except that no additional carrier dabbing or wiping normally is desired, on a continuous multihole machine with each of such reduction steps representing as much as one B & S draft at practical wire drawing speeds up to 400 feet per minute and over. In the case of aluminum clad steel wire so drawn the thickness of the aluminum cladding may represent a cross section in the amount of 20% or more of aluminum in the total cross sectional area of the clad wire. The lubricant coating remaining on the wire may readily be removed by a vapor detergent bath or liquid acid cleaning.

Die drawing tests on aluminum clad steel wire at block speeds as high as 400 feet per minute have shown that when the approach angle 52 of the die 36 and the approach angle of the die 37 are from about 12 to 16, they are satisfactory. Further, the respective average radial clearances from the bearings in those dies are preferably about 0.0025 inch and 0.001 inch, representing an average radial distance from the outside of the clad wire to the Wall of the respective bearing portion. A diameter at the bearing in the pressure dies which is not more than 0.010 of an inch larger than the clad wire diameter appears to represent the maximum clearance tolerance for achievement of a suitable pressure extrusion effect with such aluminum clad steel wire. In the case of the drawing die 38, the preferable approach angle 53 should be about 6 with a maximum of about 12 when die 38 is the first reduction die, a somewhat larger approach angle being tolerable in succeeding reduction steps when the clad wire carried the coating of lubricant thereon. All of the dies were flared for relief on the exit side of their respective bearing portions. A carrier, dag No. 200 sold by Acheson Colloids Company, was used just ahead of the first draft and the fine powder soap lubricant used was Standard Industrial Compound No. 55 XXX. And, the resistance to the pulling of the clad wire being reduced appears to be taken up by the reduction die itself.

Various changes may be made in the illustrated embodiment, and other embodiments and materials used, without departing from the spirit of our invention or the scope of the appended claims.

We claim:

1. In die drawing aluminous or the like clad ferrous or the like core rod or wire in which the cladding is a continuous, coherent covering of appreciable thickness bonded to said core, the steps comprising, in combination, applying a tacky substance to said clad rod or wire, pulling it through a fine powder die drawing soap lubricant compatible with said cladding to picl; up a lubricant coating then pulling it through at least one pressure die having a bearing diameter slightly larger than the diameter of said clad rod or wire to prevent counter movement of lubricant, then drawing it through a succeeding coaxial reduction die in sealed relation to the back of said pressure die and having a bearing diameter a draft amount less than the diameter of said clad rod or wire, said dies defining a sealed space between said dies, maintaining a very high pressure of lubricant in said space by movement of said clad rod.or wire therethrough sufiicient to resist formation of a progressively increasing transverse circumferential shoulder in said cladding by said reduction die, and subjecting said clad rod or wire to pressure caused by lubricant carried into said space by said clad rod or Wire sufficient to force said cladding to pass through said reduction die along with said core for drawing of said cladding uniformly with said core and to cover the drawn clad rod or wire during its reduction passage through said reduction die with an enveloping thin layer of lubricant continuous along and around the same, said reduction die having its exit at much lower pressure than said firstnamed pressure, whereby proportionate reduction is provided in the cladding and core of said clad rod or wire without stripping, scoring or upsetting said cladding.

2. A die drawing device for a clad rod or wire having a softer metal cladding and a harder metal core, comprising, in combination, means for lubricating the surface of said clad rod or wire comprising means to apply powder soap lubricant to said clad rod or wire in advance of any pressure die, at least a pair of pressure dies each having a central opening therethrough with a relatively straight-sided approach angle and a cylindrical bearing portion with a diameter slightly larger than that of said clad rod or wire to pass lubricant therewith and prevent countermovement of said lubricant, said pair of such pressure dies being in coaxial succession with the space between them also sealed to provide an operative pressure space, a coaxial reduction die having a smaller central opening therethrough with a generally narrow relatively straight-sided approach angle not to exceed in the neighborhood of from about 6 to about 12 and a cylindrical bearing portion, a sealing ring substantially in engagement with the rear face of the last pressure die and the front face of said reduction die, said sealing ring having a central opening to clear said clad rod or wire passing through from said last pressure die, said reduction die being operative substantially to take up the resistance to reduction offered by said clad rod or wire to being drawn, said dies and ring being in coaxial alignment and the space following said reduction die affording relief for the drawn clad rod and wire, and mounting means for holding said dies axially pressed together to seal the central opening spaces between them and to hold them rigidly against longitudinal and transverse movement, said central opening space between said last pressure die and said reduction die being operative to provide a very high pressure chamber to force said cladding metal to pass through said reduction die without upsetting and concurrently with said core metal with a continuous layer of lubricant on the surface of said drawn clad rod or wire, whereby a clad rod or wire will carry lubricant into the space sealed by said sealing ring to provide a very high pressure in said last-mentioned central opening space operative to promote uniform drawing of said cladding and core in said clad rod or wire by said reduction die.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,080,962 March 12, 1963 Ernst Fleischmann et a1,

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, Times 12 and 13, for "comprised" read comprises line 45, after "in" insert the o Signed and sealed this 17th day of September 1963.-

(SEAL) Attest:

DAVID L. LADD Commissioner of Patents ERNEST W. SWIDER Attesting Officer

Claims (2)

1. IN DIE DRAWING ALUMIOUS OR THE LIKE CLAD FERRROUS OR THE LIKE CORE ROD OR WIRE IN WHICH THE CLADDING IS A CONTINUOUS, COHERENT COVERING OF APPRECIABBLE THICKNESS BONDED TO SAID CORE, THE STEPS COMPRISING, IN COMBINATION,, APPLYING A TACKY SUBSTANCE TO SAID CLAD ROD OR WIRE, PULL: ING IT THROUGH A FINE POWDER DIE DRAWING SOAP LUBIRCANT COMPATIBLE WITH SAID CLADDING TO PICK UP A LUBRICANT COATING THEN PULLING IT THROUGH AT LEAST ONE PRESSURE DIE HAVING A BEARING DIAMETER SLIGHTLY LARGER THAN THE DIAMETER OF SAID CLAD ROD OR WIRE TO PREVENT COUNTER MOVEMENT OF LUBRICANT, THEN DRAWING IT THROUGH A SUCCEEDING COAXIAL REDUCTION DIE IN SEALED RELATION TO THE BACK OF SAID PRESSURE DIE AND HAVING A BEARING DIAMETER A DRAFT AMOUNT LESS THAN THE DIAMETER OF SAID CLAD ROD OR WIRE, SAID DIES DEFINING A SEALED SPACE BETWEEN SAID DIES, MAINTAINING A VERY HIGH PRESSURE OF LUBRICANT IN SAID SPACE BY MOVEMENT OF SAID CLAD ROD OR WIRE THERETHROUGH SUFFICIENT TO RESIST FORMATION OF A PROGRESSIVELY INCREASING TRANSVERSE CIRCUMFERENTIAL SHOULDER IN SAID CLADDING BY SAID REDUCTION DIE, SAID SUBJECTING SAID CLAD ROD OR WIRE TO PRESSURE CAUSED BY LUBRICANT CARRIED INTO SAID SPACE BY SAID CLAD ROD OR WIRE SUFFICIENT TO FORCE SAID CLADDING TO PASS THROUGH SAID REDUCTION DIE ALONG WITH SAID CORE FOR DRAWING OF SAID CLADDING UNIFORMLY WITH SAID CORE AND TO RECOVER THE DRAWN CLAD ROD OR WIRE DURING ITS REDUCTIION PASSAGE THROUGH SAID REDUCTION DIE WITH AN ENVELOPING THIN LAYER OF LUBRICANT CONTINUOUS ALONG AND AROUND THE SAME, SAID REDUCTION DIE HAVING ITS EXIST AT MUCH LOWER PRESSURE THAN SAID FIRST NAMED PRESSURE, WHEREBY PROPORTIONATE REDUCTION IS PROVIDED IN THE CLADDING AND CORE OF SAID CLAD ROD OR WIRE WITHOUT STRIPPING, SCORING OR UPSETTING SAID CALDDING.

2. A DIE DRAWING DEVICE FOR A CLAD ROD OR WIRE HAVING A SOFTER METAL CLADDING AND A HARDER METAL CORE, COMPRISING, IN COMBINATION, MEANS FOR LUBRICATING THE SURFACE OF SAID CLAD ROD OR WIRE COMPRISING MEANS TO AAPPLY POWDER SAOP LUBRICANT TO SAID CLAD ROD OR WIRE IN ADVANCE OF ANY PRESSURE DIE, AT LEAST A PAIR OF PRESSURE DIES EACH HAVING A CENTRAL OPENING THERETHROUGH WITH A RELATIVELY STRAIGHT-SIDED APPROACH ANGLE AND A CULINDRICAL BEARING PORTION WITH A DIAMETER SLIGHTLY LARGER THAN THAT OF SAID CLAD ROD OR WIRE TO PASS LUBRICANT THEREWITH AND PREVENT COUNTERMOVEMENT OF SAID LUBRICANT, SAID PAIR OF SUCH PRESSURE DIES BEING COAXIAL SUCCESSION WITH THE SPACE BETWEEN THEM ALSO SEALED TO PROVIDE AN OPERATIVE PPRESSURE SPACE, A COAXIAL REDUCTION DIE HAVING A SMALLER CENTRAL OPENING THERETHROUGH WITH A GENERALLY NARROW RELATIVELY STRAIGHT-SIDED APPROACH ANGLE NOT TO EXCEED IN THE NEIGHBORHOOD OF FROM ABOUT 6* TO ABOUT 12* AND A CYLINDRICAL BEARING POTION, A SEALING RING SUBSTANTIALLY IN ENGAGEMENT WITH THE REAR FACE OF THE LAST PRESSURE DIE AND THE FRONT FACE OF SAID REDUCTION DIE, SAID SEALING RING HAVING A CENTRAL OPENING TO CLAER SAID CLAD ROD OR WIRE PASSING THROUGH FROM SAID LAST PPRESSURE DIE, SAID REDUCTION DIE BEING OPERATIVE SUBSTANTIALLY TO TAKE UP THE RESISTANCE TO REDUCTION OFFERED BY SAID CLAD ROD OR WIRE TO BEING DRAWN, SAID DIES AND RING BEING COAXIAL ALIGNMENT AND THE SPACE FOLLOWING SAID REDUCTION DIE AFFORDING RELIEF TO THE DRAWN CLAD ROD AND WIRE, AND MOUNTING MEANS FOR HOLDING SAID DIES AXIALLY PRESSED TOGETHER TO SEAL THE CENTRAL OPENING SPACES BETWEEN THEM AND TO HOLD THEM RIGIDLY AGAINST LONGITUDINAL AND TRANSVERSE MOVEMENT, SAID CENTRAL OPENING SSPACE BETWEEN SAID LAST PRESSURE DIE AND SAID REDUCTION DIE BEING OPERATIVE TO PROVIDE A VERY HIGH PRESSURE CHAMBER TO FORCE SAID CLADDING METAL TO PASS THROUGH SAID REDUCTION DOE WITHOUT UPSETTING AND CONCURRENTLY WITH SAID CORE METAL WITH A CONTINUOUS LAYER OF LUBRICANT ON THE SURFACE OF SAID DRAWN CLAD ROD OR WIRE, WHEREBY A CLAD ROD OR WIRE WILL CARRY LUBRICANT INTO THE SPACE SEALED BY SAID SEALING RING TO PROVIDE A VERY HIGH PRESSURE IN SAID LAST-MENTIONED CENTRAL OPENING SPACE OPERATIVE TO PROMOTE UNIFORM DRAWING OF SAID CLADDING AND CORE IN SAID CLAD ROD OR WIRE BY SAID REDUCTION DIE.

Images