US3839895A

US3839895A - Method of drawing wire and apparatus therefor

Info

Publication number: US3839895A
Application number: US00313686A
Authority: US
Inventors: H Akachi; T Abe
Original assignee: Oki Electric Cable Co Ltd
Current assignee: Oki Electric Cable Co Ltd
Priority date: 1972-07-04
Filing date: 1972-12-11
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08
Also published as: GB1418677A; DE2300516C3; IT974173B; DE2300516B2; FR2190538B1; FR2190538A1; CA971910A; JPS4926170A; DE2300516A1

Abstract

A wire drawing die is maintained horizontally in a floating condition by the aid of fluid pressure which is constantly imparted to a pressure-receiving member carrying the die so that the die is horizontally movable together with the pressurereceiving member when subjected to a force exerted in a horizontal direction. The wire is thus drawn constantly in a perfectly straight vertical path so that the die is subject to friction and load which are uniform throughout a circumference of the die and that the resultant drawn wire is free from curls and kinks that would otherwise result from irregular stress produced in the wire.

Description

United States Patent [191 Akachi et a1.

[ 1 OCL8,1974

[ METHOD OF DRAWING WIRE AND APPARATUS THEREFOR [75] Inventors: Hisateru Akachi, Yokohama;

Toshlhiro Abe, Kawasaki, both of Japan [73] Assignee: Oki Densen Kabushiki Kaisha,

Kawasaki, Japan [22] Filed: Dec. 11, 1972 [21] Appl. No.: 313,686

[30] Foreign Application Priority Data July 4, 1972 0 Japan 47-67405 [52] US. EL- 72/285 [51] Int. Cl. B2lc 3/12 [58] Field of Search 72/274, 278, 282, 285, 72/291, 465, 467

[56] References Cited UNITED'STATES PATENTS 1,297,825 3/1919 Fuller 72/467- 2,088,040 7/1937 Simons et a1. 72/282 2,580,454 1/1952 Musser 72/465 3,664,169 5/1972 Henrich 72/467 R20,067 8/1936 Busey 72/467 Primary Examiner-Charles W. Lanham Assistant Examiner-M. J. Keenan Attorney, Agent, or Firm-Kurt Kelman; Hans Berman [5 7 ABSTRACT A wire drawing die is maintain-ed horizontally in a floating condition by the aid of fluid pressure which is constantly imparted to a pressure-receiving member carrying the die so that the die is horizontally movable together with the pressure-receiving member when subjected to a force exerted in a horizontal direction. The wire .is thus drawn constantly in a perfectly straight vertical path so that the die is subject to friction and load which are uniform throughout a circumference of the dieand that the resultant drawn wire is free from curls and kinks that would otherwise result from irregular stress. produced in the wire.

17 Claims, 8 Drawing Figures PATENTEU 84974 3.839.895

SHEET 1 0f 5 F lGJa PATENTEB f"Q74 3.839.895

SKEI 30? 5 METHOD OF DRAWING WIRE AND APPARATUS THEREFOR The present invention relates to the manufacture of wire from metals and more particularly to a method of and apparatus for drawing a wire from a rod of metal.

The wire is commonly formed by drawing the metal such as a rolled wire rod through a succession of wire drawing dies, each one progressively smaller than the preceding one, until the wire has been reducedin diameter to the desired final size, although a single draft wire drawingmethod is still in wide use. The die has a die hole which is tapered from the diameter of the supplied wire rod at its entrance to the smaller desired diameter of the drawn wire at an' exit of the die hole. For the purpose that the wire is drawn in a stable condition, it is of crucial importance that the wire rod be fed to and passed through the die and the resultant wire pulled from the die in a constantly straight path which is in strict alignment with an axis of the die hole or, in other words, the load exerted axially on the wire rod entering the die hole and the tension produced in the wire leaving the die hole occur in a direction which is perfectly perpendicular to the direction in which the wire rod is contracted in the die hole. Where the wire is drawn under this optimum condition, the die is subject to load and friction and accordingly to wear and abrasion which are constantly uniform at its entire inner peripheral surface defining the die hole so that a prolonged service life of the die can be eventually assured.

When the wire drawing die is subjected to localized or irregular load and friction on limited areas of its working surface, then serious deformation will be invited at the particular areas and the deformation thus brought about will in turn result in an unusual mechanical resistance or physical interference exerted'on the wire or wire rod which is being passed through the die hole during operation. Such an unusual resistance urges the development of the deformation of the die surface and gives rise to an accelerated wear and abrasion of the die. The application of the localized load and friction to the die surface further tends to cause irregular distribution of a lubricant to be applied to the wire rod entering the die hole and thus results in direct, unprotected contact between the die surface and wire, providing another important source of the wear of the die.

Since, moreover, the wire which has been drawn in the best possible operating condition above described is under tensile strain which is uniform circumferentially of the sectional area of the wire, the wire is not only free from curls in itself but is substantially prevented from being formed with kinks in the subsequent steps of the wire production. This provides utmostease of handling of the wire in the steps which are subsequent to the wire drawing process, especially where those wires which have relatively high elastic modulus such as musical wires and beryllium-copper wires are to be manufactured.

All these prominent advantages which are achievable from the previously described wire drawing condition have long been pointed out by those skilled in the art 2 drawing dies and the dieposition adjusting mechanisms. The use of the rotary wire drawing dies and the dieposition adjusting mechanisms in the actual wire drawing operation is, however, not fully acceptable espeand a variety of devices have thus far been proposed and put on use with a view to realizing such advantages. Typical of these prior art devices will be the rotary wire cially in the continuous wire drawing machines because driving a number of dies results in a considerable loss of power which might be otherwise avoided and because precise adjustment of the die positions during operation results in a considerable decrease in the production efficiency. A comparatively advanced wire drawing arrangement has therefore been proposed wherein awire drawing die is in sliding contact with an underside of a horizontaol member and the wire is drawn vertically upwardly from below the die which is thus urged to bear against the overlying horizontal member. This arrangement appears to have attained a considerable success where the wire is drawn with a ,force which is slightly greater than the weight of the die. Whenthe drawing effort exerted on the wire is thus only slightly greater than the weight of the die, only a minimal amount of frictional force is produced be tween the contacting surfaces of the die and horizontal member so that the wire is allowed to smoothly relocate itself against such a minimal friction by reason of the interaction between the drawing force applied to the wire and the axial load exerted on the wire rod. Where, however, it isrequired that the wire be drawn with a force exceeding the weight of the die, an increased amount of frictional force is built up between the die and the overlying lower face of the horizontal member so that the die is hindered by such a frictional force from accurately moving to a position in which the directions of the axial load on the incoming wire rod and the tension in the outgoing wire are aligned with each other. It may be added that the wire drawing arrangement of the described character is entirely useless for the drawing of wires having extremely small tensile strengths as in drawing an annealed copper wire of 0.025 mm diameter which should be drawn with a force of about 8 grams. The present invention contemplates elimination of all the above mentioned drawbacks that are inherent in the prior art wire drawing techniques, especially in the arrangement using a horizontal member which cooperates with the wire drawing die. The present invention has thus been completedon the basis of a discovery that unobstructed movement of the wire drawing die especially in a horizontal plane can be achieved if the wire is drawn from the die with a force which is appreciably greater than a force opposing the drawing effort in a vertical direction.

It is accordingly an important object of the present invention to provide a new and useful method of drawing a wire in such a condition that the wire rod is fed to and passed through the drawing die and the resultant wire pulled from the die in a substantially straight vertical path throughout the wire drawing operation.

it is another important object of the invention to pro vide a new and useful method of drawing a wire wherein the directions of the axial load exerted on the wire rod entering the drawing die and the tension produced in the wire leaving the die are substantially perfectly perpendicular to the direction in which the wire rod is contracted or compressed when passing through the die hole.

I It, is still another important object of the invention to provide anew and useful methodof drawing a wire cally adjusted to an optimum position without aid of any position-adjusting mechanism.

It is still another important object of the invention to provide a new and useful method of drawing a wire wherein the wire drawing die has its inner peripheral surface subjected to load and friction which are substantially uniform along the entire circumference of the surface.

It is still another important object of the invention to provide a new and useful method of drawing a wire assuring a prolonged service life of the wire drawing die.

Itis still another important object of the invention to provide a new and useful method of drawing a wire which is substantially free from curls and kinks.

It is still another important object of the invention to provide a new and useful method of drawing a wire ,wherein the wire drawing die is allowed to move substantially freely to a position in which the die hole or more exactly a vertical axis of the die hole is accurately aligned with the direction of advancement of the incoming wire rod and the outgoing wire at any instant during the wire drawing operation.

It is still another important object of the invention to provide a new and useful method of forming a drawnwire at an increased production rate and without a substantial loss of power during production.

Yet, it is another important object of the present invention to provide a wire drawing apparatus which is specifically adapted to put the above mentioned new and useful method into practice in a simple and economical construction.

It is a further object of the invention to provide a wire drawing apparatus featuring a versatility of operation which is adaptable to the drawing of wire of any material, mechanical property and size on a large-scale commercial production basis.

The method to achieve these objects of the present .invention comprises the concurrent and continuous steps of advancing a wire rod in a substantially straight vertical path toward a movable constriction or die having a predetermined internal diameter and a central axis which is substantiallyin line with the straight vertical path, forcing the wire rod through the constriction for compressing the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diameter of the constriction, drawing the wire from the constriction with a predetermined force and in a substantially. straight vertical path which is substantially in line with the central axis of the constriction, and directing a fluid vertically and substantially uniformly onto a horizontal pressurereceiving member having a predetermined amount of weight and movable with the constriction in any direc tion for imparting to the pressure-receiving member a vertical force which is substantially equal to the force resulting from the weight of the pressure-receiving member and the drawing force on the wire whereby the pressure-receiving member and constriction are maintained in a substantially floating condition relative to the wire and wire rod.

According to another aspect of the present invention, the method to achieve the previously mentioned objects may comprise the concurrent and continuous steps of downwardly advancing a wire rod in a substantially straight vertical path toward a movable constriction or die having a predetermined internal diameter and a central axis which is substantially in line with the path of the wire rod. forcing the wire rod through the constriction for compressing the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diameter of the constriction, downwardly drawing the wire from the constriction in a substanstially straight vertical path which is substantially in line with the central axis of the constriction, and directing a fluid upwardly and substantially uniformly onto a horizontal pressurereceiving member having a predetermined amount of weight and movable with the constriction in any direction for applying to the pressure-receiving member a lifting force which is substantially equal to the sum of the amount of weight of the pressure-receiving member and the drawing force on the wire whereby the pressure-receiving member is maintained in a substantially floatingcondition relative to the wire and wire rod.

In accordance with still another aspect of the present invention, the method may comprise the concurrent and continuous steps of upwardly advancing a wire rod in a substantially straight vertical path toward a movable constriction or die having a predetermined internal diameter and a central axis which is substantially in line with the path of the wire rod, forcing the wire rod through the constriction for compressing the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diameter of the constriction, upwardly drawing the wire from the constriction in a substantially straight vertical path which is substantially in line with the central axis of the constriction, and directing a fluid under pressure vertically and substantially uniformly onto a horizontal pressure-receiving member having a predetermined amount of weight and movable with the constriction in any direction for imparting to the pressure-receiving member a downward force which is substantially equal to the difference between the amount of weight of the pressure-receiving member and the drawing force on the wire whereby the pressure-receiving member is maintained in a substantially floating condition relative to the wire and wire rod. The downward force applied to the pressure-receiving member may be exerted by ejecting the fluid under pressure downwardly onto the pressure-receiving member for establishing a downward pressure acting on an upper side of the member or by ejecting the fluid under pressure in the vicinityof the underside of the pressure-receiving member for establishing a suction underneath the member.

According to still another aspect of the present invention, the method of drawing a wire may comprise the concurrent and continuous steps of upwardly advancing a wire rod in a substantially straight vertical path toward a movable constriction or die having a predetermined internal diameter and a central axis which is substantially in line withthe path of the wire rod, forcing the wire rod through the constriction for compressing the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diameter of the constriction, upwardly drawing the wire from the constriction in a substantially straight vertical path which is substantially in line with the central axis of the constriction, and directing a fluid upwardly and substantially uniformly onto a horizontal pressure-receiving member having a prede vtermined amount'of weight and movable with the constriction in any direction for imparting to the pressurereceiving member a lifting force which is substantially equal to the difference between the amount of weight of the pressure-receiving member and the drawing force on the wire whereby the pressure-receiving member and constriction are maintained in a substantially floating condition relative to thewire and wire rod.

Where it is desired to have the pressure-receiving member urged upward by the lifting force of the fluid with the wire drawn either upward or downward from the constriction, the fluid may be supplied under pressure and ejected upwardly onto the pressure-receiving member for establishing an upward pressure acting on the underside of the member or the fluid may be stored in a vessel for floating therein the pressure-receiving member and constriction by buoyancy ther'eof.

The apparatus adapted to carry out the above de-, scribed method comprises in combination a die having formed centrally therein a constricted passage having a vertical central axis, a horizontal pressure-receiving member movable with the die and having a predetermined amount of weight, the pressure-receiving member having a horizontal working surface which is substantially symmetrical with respect to the passage in the die, a horizontal fluid circulation chamber which is powith respect to the central axis of the passage in the die,

a horizontal annular fluid circulation chamber posi' tioned vertically adjacent to the pressure-receiving member and having a horizontal annular end wall facing the working surface of the pressure-receiving member and formed with a number of apertures which are distributed substantially evenly throughout the end wall and a vertical bore formed centrally of the fluid circulation chamber and extending substantially in line with the central axis of the passage in the die, the axial bore being sufficiently larger in diameter than the passage in the die, and means for continuously feeding a fluid is positioned to have its horizontal apertured end wall sitioned vertically adjacent to the working surface of 5 the pressure-receivingmember and which has formed substantially centrally thereof a vertical bore extending substantially in line with the central axis of the passage and greater in diameter than the passage, and means to supply a fluid into the fluid circulation chamber for directingthe fluid from the chamber vertically and substantially uniformly onto the working surface of the pressure-receiving member for imparting a predetermined vertical force to the pressure-receiving member.

, second variations are such that the pressure-receiving member and die are urged in a direction opposite to the direction of advancement of the wire, a third variation is adapted to have the pressure-receiving member and die urged upwardly by the action of the fluid' and the wire is also drawn upwardly from the constriction in the die, In any of the variations above mentioned, it is irnportant that the pressure-receiving member and the die are free from an applied force having a horizontal component.

The fluid directed onto the pressure-receiving member may act thereupon in either dynamic or static fashion. Where it is desired that the fluid dynamically act on the pressure-receiving member, the wire drawing apparatus according to the present invention may comprise, in combination, a die having formed substantially centrally thereof a passage having a vertical central axis, a horizontal pressure-receiving member having a predetermined amount of weight and movable with the.

at the top and in oppositely facing relation to the overlying working surface of the pressure-receiving member, whereinthe fluid under pressure emitting from the apertures in the top end wall of the fluid circulation chamber is directed upwardly onto the working surface of the pressure-receiving member. Or. otherwise, the pressure-receiving member may be positioned below the fluid circulation chamber with its working surface at the top. In this instance, the fluid circulation chamber is positioned to have its horizontal apertured end wall at the bottom so as to be in oppositely facing rela' tion to the underlying working surface'of the pressurereceiving member so that the fluid under pressure is emitted downwardly through the apertures in the bottom end wall of the fluid circulation chamber so as to urge the pressure-receiving member and die downwardly.

Where, on the other hand, it is desired that the pressure-receiving member be acted upon by the fluid in the static fashion as previously noted, the wire drawing apparatus according to the present invention may comprise, in combination, a die having formed substantially centrally thereof a constricted passage having a vertical central axis, a horizontal pressure-receiving member movable with the die and having a vertical bore which is substantially in line with the central axis of the constriction in the die, the pressure-receiving member having a substantially uniform density distribution and a 1 working surface which is substantially symmetrical with respect to the central axis of the passage, and a vessel storing a liquid therein for floating the pressurereceiving member and die in the: liquid and having a vertical bore which is substantially in line with the central axis of the passage and the vertical bore in the pressure-receiving member.

While the general features of the method and apparatus according to the present invention have thus far been described, such will be better understood from the followingdescription of the invention taken in conjunction with the accompanying drawings wherein corresponding parts and elements in the several figures are designated by'like reference numeralsand in which:

FIG. In is a cross sectional view of a prefered embodiment of the wire drawing apparatus according to working surface which is subatantially symmetrical the present invention;

FIG. lb is a top plan view of the wire drawing apparatus shown in FIG. la;

FIG. 2 is a graph indicating the relation between the pressure of air emitted through the apertures in the fluid circulation chamber and the suction resulting from a rapid stream of air thus produced between the fluid circulation chamber and the overlying working surface of the pressure-receiving member in the apparatus shown in FIGS. la and lb;

FIG. 3a is a cross sectional view showing another preferred embodiment of the wire drawing apparatus according to the present invention;

FIG. 3b is a bottom end view of the fluid circulation chamber of the apparatus shown in FIG. 3a, the view being taken on line ll of FIG. 3a;

FIG. 4a is a view similar to FIG. 3a of still another preferred embodiment of the apparatus according to the present invention;

FIG. 4b is a top end view of the fluid circulation chamber of the apparatus shown in FIG. 4a, the view being taken on a plane indicated by line llIl of FIG. 4a; and

FIG. 5 is a cross sectional view showing still another preferred embodiment of the wire drawing apparatus according to the present invention.

Reference will now be made to FIGS. 1a and lb, wherein a wire rod which has been previously rolled from a billet in a rod mill (not shown) is fed vertically downwardly in a substantially straight path to the shown wire drawing apparatus and is drawn by a roller 8 into a wire 12 having a reduced desired diameter. A die 14 is securely received in a vertical hole 16 formed substantially centrally of a horizontal pressurereceiving member or die block 18 having a predetermined amount of weight. The die 14 is usually formed of tungsten carbide or diamond to withstand the wear and pull by the wire rod 10 and wire 12 and has a vertical constricted passage or die hole 20 which is formed substantially centrally thereof and concentrically with the central hole 16 in the-die block 18. The die hole 20 is tapered from the diameter of the wire rod 10 at its entrance to the smaller desired diameter of the drawn wire 12 at an-exit of the die hole 20. Likewise, the central hole 16 in the die block 18 is enlarged vertically toward its ends so as not to interfere with the entry of the wire rod 10 into the die hole 20 and the withdrawal of the drawn wire 12 from the die hole as seen in FIG. la. The die block 18 is illustrated in FIG. lb as being in a circular disc form by way of example. Where desired, however, the die block 18 may be shaped in any desired manner insofar as the die block in its entirety is substantially symmetrical with respect to a central axis of the die hole 20L Underneath the die block 18 is positioned a horizontal annular fluid circulation chamber 22 having a central bore 24 extending vertically in line with the central axis of the die hole 20 for passing therethrough the wire 12 emerging downwardly from the die hole. To prevent the wire 12 from being interfered with when passing through this vertical bore 24, it is preferable that the bore 24 in the fluid circulation chamber 22 has a diameter which is larger than the diameter of the central hole 16 in the die block H8. The fluid circulation chamber 22 has a horizontal annular top wall 26 which is positioned in oppositely facing relation to the overlying working surface of the die block 18. The annular top wall 26 has formed therein a number of apertures or nozzles 28 which are distributed substantially uniformly throughout the wall 26, preferably symmetrically with respect to a central axis of the vertical bore 24 in the die block 18, viz., to the center of the overlying die block 18, as better seen in FIG. lb. The fluid circulation chamber 22 has a flange 30 through which the chamber 22 is securely supported on a suitable stationary member 32 by suitable fastening means such as bolts 34 in a manner to hold its annular top wall 26 on a strictly horizontal plane.

The fluid circulation chamber 22 further has a fluid inlet port 36 which is in constant communication with a suitable source (not shown) of fluid under pressure through a conduit 38. This conduit 38 has incorporated therein suitable flow control and pressure regulator means for controlling the rate of flow and the pressure of the fluid to be supplied to the fluid circulation chamber 22 during operation, though not herein shown. The fluid thus directed into the fluid circulation chamber 22 through the conduit 38 at a predetermined rate and under a predetermined pressure is circulated uniformly in the chamber 22 so as to establish a constant and uniform pressure throughout the chamber and is thereafter discharged vertically upward through the apertures 28 in the annular top wall 26. The apertures 28 being uniformly distributed with respect to the working surface of the overlying die block 18 as previously mentioned, the die block 18 is subjected to a constant and uniform fluid pressure from these apertures 28 and is consequently urged upwardly, viz., vertically away from the annular top wall 26 of the chamber 22 while being maintained horizontal. During operation in which the wire 12 is drawn downwardly through the die hole 20 as indicated by arrows in full line in FIG. 1a, the die assembly consisting of die 14 and die block 18 is subjected to two downward forces, namely, the force of gravity and the drawing force exerted on the wire 12 or the axial load on the wire rod 10 at the entrance of the die 14 and to an upward force resulting from the fluid pressure exerted on the working surface of the die block 18. If, thus, the pressure and flow rate of the fluid directed into the fluid circulation chamber 22 are regulated appropriately, the fluid pressure acting on the die block l8 will overcome the combined opposingforces, that is, the force of gravity and the drawing force on the wire 12 or the axial load on the wire rod 10 entering the die 14, thereby maintaining the die block 18 to float over the top wall 26 and relative to the wire 10 and wire rod 12 as seen in FIG. la. In the absence of a horizontal restraint or biasing force exercised on the die block 18 and die 14, the die block 18 is allowed to substantially freely move in a horizontal direction over and relative to the underlying annular top wall 26 of the chamber 22 if and when subjected to a slight horizontal force or a force having a horizontal component by the wire rod 10 or wire 12 which is being pulled through the die 14.

If, therefore, it happens that the central axis of the die hole 20 is vertically misaligned with the direction or directions of either or both of the wire rod 10 and wire 12, then the die block 18 will be moved to a position in which the central axis of the die hole 20 is brought into strict alignment with the directions of advancement of the wire rod 10 and wire 12. The die 14 is in this manner maintained at all times in an optimum position relative to the wire rod Ill and wire 12 insofar as l) the die hole 20 has its central axis exactly perpendicular to the working surface of the die block 18, (2) the die block 18 and the annular top wall 260i the fluid may be compressed air or liquid such as oil which is pumped to the fluid circulation chamber 22. Where the compressed air is tobe utilized, the wire drawing apparatus of the construction shown in FIGS. 1a and 1!) may be modified especially for its arrangement of fluid circulation chamber 22 so that the streamof air Spurting at a high velocity from the apertures or nozzles 28 in the annular top wall 26 of the chamber 22 builds up a suction between the lower working surface of the die block 18 and the upper surface of the annular top wall 26. In this instance, the wire should be drawn upwardly as indicated by arrows in broken line in FIG. Ia and is thus resisted by the combined forces of gravity acting on the die block 18 and the suction urging the die block 18 downwardly toward the annular top wall of the fluid circulation chamber 22. To enable the die block 18 to float over the upper face of the annular top wall 26 of the fluid circulation chamber 22 in a constantly stabilized condition, it is important that the downward forces resulting from the weight of the die block 18 and the suction established between the die block 18 and the underlying annular top wall 26 of the chamber 22 be approximately equal to the drawing force on the wire. The suction built up by the stream of air between the die block 18 and the annular top wall 26 can be varied depending upon the required drawing force by varying the pressure of the air to be directed into the fluid circulation chamber 22 as will be understood from the curve of FIG. 2.

The arrangement of the nature above described will be especially suitable for the drawing of a wire having a relatively small tensile strength because of the limited amount of weight of the die block 18 and because of the fact that the suction acting upon the die block 18 isfar smaller in absolute value than the pressure applied to the die block in the arrangement previously described. The die block'l8 can thus be constantlymaintained in the stabilized condition floating over the upper surface of the annular top wall 26 of the fluid circulation chamber 22 by reason of the limited amount of restriction exercised thereon even though the wire is drawn by an extremely small force. Where the prevention of breakage of the wire being drawn is a serious requirement as in the case of the drawing ofa wire of precious metal, the sum of the amount of weight of the die block I8 and the suction exerted on the die block should be so selected as to be substantially equal to the drawing force on the wire and smaller than a tensile breaking load of the wire. Since, in this instance, the suction can be varied minutely by controlling the pressure of the air to be directed into the fluid circulation chamber as pointed out above, such a requirement will be readily met with for the drawing of wires of any size and material. Where the die block 18 is subjected to a relative to the underlying annular top wall 26 of the fluid circulation chamber 22 and will therefore be free from vibratory actions during operation.

Where desired. the wire drawing apparatus having the construction shown in FIGS. la and llb may be used in a vertically inverted form with its die block posi tioned underneath the fluid circulation chamber. A preferred embodiment of the wire drawing apparatus adapted to achieve this end is now shown in FIGS. 30 and 312 wherein the fluid used is assumed to be a lubrieating oil.

Referring to FIGS. 3a and 3b, the die block I8 having the die 14 embedded centrally therein is carried on a substantially central portion of a lower face of a circular die holder 46 which now acts as a pressure-receiving member having an upper working surface which is substantially symmetrical with respect to the die I4 and die block 18. The die 14 is adapted to draw the wire which is pulled upwardly as indicated by arrows in FIG. 3a. The die holder 40 has formed substantially centrally therein an aperture 42 which is in strict alignment with the vertical axes of the central holes in the die 14 and die block 18. The die holder 46 is positioned below the annular fluid circulation chamber 22 in a manner that the central aperture 42 of the die holder is substantially in line with the central vertical bore 24 in the chamber 22. The fluid circulation chamber 22 has an annular bottom wall 26 which is formed with a number of aper tures 28 distributed substantially evenly throughout the annular bottom wall 26, preferably radially about and equidistantly from the center of the wall as clearly seen in FIG. 3b. The fluid circulation chamber 22 is herein shown as further having an annular top wall 44 which seals the upper end of the chamber 22. The fluid circulation chamber 22 is fastened on a lower face of the stationary member 32 by means of the bolts 34. This stationary member 32 is formed with an aperture 46 which is aligned with the central vertical bore 24 in the fluid circulation chamber 22. The fluid circulation chamber 22 is in communication with a suitable source (not shown) of a lubricating oil through the conduit 38 so that the lubricating oil is pumped into fluid circulation chamber 22 at a predetermined rate and is evenly circulated throughout the chamber, as indicated by reference numeral 52 in FIG. 3a. The lubricating oil is then forced downwardly out of the apertures 28 in the annular bottomwall 26' of the fluid circulation chamber 22 and impinges upon the upper working surface of the underlying die holder 40 for urging the die holder 40 downwardly away from the lower surface of the annular bottom wall 26. The lubricating oil then drops off the outer perimeter of the die holder 40 and is stored in a suitable sump (not shown) as indicated by reference numeral 52' in FIG. 3a. The lower surface of the annular bottom wall 26' of the fluid circulation chamber 22 and the upper working surface of the die holder 40 are mirror finished.

To prevent the drawn wire ll2 leaving the die 14 frombeing exposed to the lubricating oil flowing between the opposite surfaces of the annular bottom wall 26 and die holder 40, the annular bottom wall 26 may be formed with at least one circular channel 48 encompassing the central vertical bore'24 and a plurality of radial channels 50 extending radially outwardly from larger amount of suction for some practical'reason, the

die block will be held in the more stabilized position the circular channel 48 and terminating at the outer perimeter of the wall 26, as seen in FIG. 3b.

During operation, the wire rod lubricated with the oil 52' in the sump positioned below the die holder 40 is upwardly forced into the central hole in the die 14 and the drawn wire 12 is pulled upwardly through the central vertical bore 24 in the fluid circulation chamber 22 and the aperture 46 in the stationary member 32. If, thus, the dynamic pressure applied to the working surface of the die holder 40 by the streams of the lubricating oil spurting out of the apertures 28 in the annular bottom wall 26 is appropriately selected, then the upward force transferred to the die holder 40 from the wire will be substantially equal to the combined downward forces-resulting from the liquid pressure acting on the die holder 40 and the weight of the die assembly mainly consisting of the die block 18 and the die holder maintained in a floating condition below the annular bottom wall 26' of the fluid circulation chamber 22 with its upper working surface held in a horizontal plane which is parallel to and appreciably spaced from the lower surface of the annular bottom wall 26 of the chamber 22. The die holder 40 is consequently substantially freely movable in the horizontal plane below the annular bottom wall 26 in response to a force exerted thereon in a direction transverse to the direction of advancement of the wire rod 10 and drawn wire 12 If, thus, it happens that either or both of the incoming wire rod 10 and the outgoing drawn wire 12 deviate from the vertical direction aligned with the axis of the central hole in the die 14 during operation, then the die holder 40 and accordingly the die 14 and die block 18 will spontaneously move to a position in which the axis working surface. The die holder 54 has formed therein a horizontal cavity 56 and a central vertical bore 58. The horizontal cavity 56 is larger in diameter than the die block '18 so that the die block 18 is horizontally of the die hole is in strict alignment with the directions 7 of advancement of the wire rod 10 and'drawn wire 12.

positioned over the fluid circulation chamber which i now has an annular top wall as in the case 'of the embodiment shown in FIGS. 1a and lb. In this instance, the wire may be drawn either upwardly or downwardly but, if it is preferred to draw the wire downwardly, a suitable lubricant may be applied to the wire rod before the wire rod enters the die hole.

The embodiments of the wire drawing apparatus thus far described are all arranged in a manner that the wires are drawn against the actions such as pressure or suction of the fluid discharged from the fluid circulation chambers. FIGS. 4a and 4b now illustrates an embodiment of the wire drawing apparatus which is adapted to draw the wire in a direction in which the wire drawing die is urged to move by the action of the fluid from the fluid circulation chamber.

The embodiment shown in FIGS. 4a and 4b uses a vcrtically inverted version of the fluid circulation chamber 22 used in the embodiment shown in FIGS. 3a and 3h so that corresponding members of the chamber 22 in both embodiments are designated by like reference numerals. Thus, the fluid circulation chamber 22 in the embodiment shown in FIGS. 40 and 4b has an annular top wall 26 having a number of apertures 28 which are evenly distributed in a radial pattern throughout the wall 26 as seen in FIG. 4b. The die block 18 carrying the wire drawing die 14 therein is supportedby a die holder 54 which serves as a pressure-receiving member having a mirror finished lower movably received therein. The die holder 54 is positioned over the annular top wall 26 of the fluid circulation chamber 22 with its central vertical bore 58 aligned with the vertical bore 24 in the chamber 22. The lubricating oil directed into the fluid circulation chamber 22 as indicated by reference numeral 52 is forced upwardly from the apertures 28 in the annular top wall 26 and impinges upon the lower working surface of the overlying die holder 56, urging the die holder 56 upwardly away from the annular top wall 26. The lubricating oil then flows outwardly from between the annular-top wall 26 and the lower surface of the die holder 54 partly through the central vertical bore 24 in the chamber 22 and partly along the outer peripheral wall of the chamber. Since, in this instance, the wire rod 10 to be drawn is fed upwardly through the central vertical bore 24, the wire rod 10 can be lubricated with the oil while it is being passed through the vertical bore 24.

The die holder 54 carrying the die block 18 and die 14 is maintained in a floating condition over the annular top wall 26 of the fluid circulation chamber 22 when the combined upward forces of the liquid pressure acting on the lower working surface of the die holder 54 and the drawing force on the wire are equal to the downward force of gravity resulting from-the weights of the die assembly, that is, essentially the die block 18 and die holder 54. The wire is therefore drawn against the weights of the die block 18 and die holder 54 and,

for this reason, it is necessary that the aggregated amount of weight of the die block 18 and die holder 54 be larger than the drawing force on the wire 12 or the axial load on the wire rod 10. If, in this regard, an annealed copper wire of a 0.08 mm diameter is to be drawn with a force of about grams so as to achieve a reduction in area of 15 percent, the combined weight of the die block 18 and die holder 54 should be larger than 70 grams. In view, moreover, of the fact that the tensile breaking load of the annealed copper wire of the particular gauge is about grams, the sum of the weights of the die block 18 and die holder 54 should be preferably over 150 grams especially where it isdesired that the wire be drawn in a sufficiently stabilized condition. Where the prevention of breakage of the wire during drawing is an important requirement, the total weight of the die block 18 and die holder should be so selected as'to be larger than the drawing force on the wire and smaller than the tensile breaking load of the wire. It will thus be understood that the embodiments illustrated in FIGS. Ia and 1b and FIGS. 3a and 3b are suitable for the drawing of wires having relatively large tensile strengths while the embodiment shown in FIGS. 40 and 4b is suitable for the drawing of wires having relatively low tensile strength.

While the wire rod 10 is forced upwardly into the die hole in the die 14 and the wire 12 is drawn upwardly from the die as indicated by arrows in full line in FIG. 4a, the die holder 54 is maintained in the floating condition over the annular top wall 26 of the fluid circulation chamber 22. Underthis condition, the die block 18 is supported by the die holder 54 in a manner that the axis of the central hole in the die 14 is aligned with the axis of the central vertical bore 58 in the die holder and that the axis of the bore 58 is aligned with the directions of advancement of the wire rod and drawn wire 12. If, in this condition, the wire rod 10 and/or the drawn wire 12 are misaligned with the axis of the central hole in the die 14, then the die holder 54 will move on a horizontal plane relative to the overlying annular top wall 26 of the fluid circulation chamber 22 while the die block 18 is moved on a horizontal plane within the cavity 56 in the die holder 54 so that the axis of the central hole in the die 14 is brought into strict alignment with the directions ofadvancernent of the wire rod 10 and drawn wire 12. The wire rod 10 and wire 12 can be fed in this manner in a perfectly vertical path throughout the'wire drawing operation even though an appreciable amount of force directed transversely of the wire or wire rod is applied to the wire or wire rod or to the die block 18 or dieholder 54.

The die block 18 has been herein assumed to be movable relative to the die holder 54 carrying the same, but the die block may be securely fitted in the cavity 58 or integral with the die holder, where preferred.

It is, furthermore, apparent that the wire drawing apparatus of the construction shown in. FIGS. 4a and 4b may be used in a manner that the wire is drawn downwardly as indicated by arrows in broken line in FIG. 4a. In this instance, the weights of the die block 18 and die holder 54, the pressure of the lubricating oil to be imparted to the die holder 54 and the drawing force on the wire should be so selected that the downward forces resulting from the weights of the die block 18 and die holder 54 and the drawing force on the wire are balanced by the liquid pressure acting upon the die holder 54 and that the weights of the die block 118 and die holder 54 are smaller than the liquid pressure on the die holder 54. Since, moreover, the drawn wire is fed downwardly through the vertical bore- 24 in the fluid circulation chamber 22, means may be provided to apply a lubricant to the wire rod entering the die hole and to prevent the drawn wire from being exposed to the lubricating oil spurting from between the lower working surface of the die holder 54 and the annular top wall 26 of the fluid circulation chamber 22. Thus, the annular top wall of the chamber 22 may be formed with at least one circular channel encircling the inlet of the vertical bore 24 and a multiplicity of radial channels extending from the circular channel and terminating at the outer perimeter of the wall 26 as is the case with the annular bottom wall 26' of the embodiment shown in FIGS. 3a and 3b.

FIG. 5 illustrates still another preferred embodiment breaking load of about 15.7 grams is drawn to achieve a reduction in area of about 10 percent, then it is necessary that a drawing force of about 6 to 7 grams be applied to the wire. If, in this instance. a die assembly having an overall weight of about 100 grams is to be used in drawing the wire, a force of about 2.5 grams will be imparted to the die assembly in a horizontal direction provided the die assembly has laterally moved appreciably from its proper position for exerting on the wire approximately one fortieth of the overall weight of the die assembly. The horizontal force of 2.5 grams may be negligible where the wire is drawnwith a force of more than 100 grams but, in drawing the wire withthe force of 6 to 7 grams, the die assembly subjected to the horizontal force of the order of 2.5 grams will no longer be able to relocate itself to the position aligned with the wire and wire rod. The embodiment illustrated in FIG. 5 is adapted to overcome this particular difficulty of the wire drawing apparatus.

Referring to FIG. 5, the die block 18 carrying the die 14 is supported on a die holder 60 which is formed of a foamed plastic or any other material having a relatively small specific gravity. The die holder 60 has formed centrally thereof upper and

lower holes

62 and 64, respectively, with which the central hole in the die 14 is strictly aligned in a vertical direction. The die block 18 is fastened on the die holder 60 by means of a retainer 66 which is screwed to orotherwise tightly of the wire drawing apparatus according to the present invention. The apparatus herein shownuses a wire drawing die whichis maintained in a horizontally movable condition by the static pressure of a liquid and is adapted for the drawing of wireswith extremely small vancement of-the wire rod. If, for example, an annealed copper wire of 0.025 mm diameter having a tensile fitted on a top wall of the die holder 60. The retainer 66 is also formed with a central hole 68 which is aligned with the central holes in the die 14 and die holder 60. Though not seen in FIG. 5, the die 14, die block 18, die holder 60 and retainer 66 have substantially circular cross sections which are concentrical with respect the axis of the central hole in the die 14. The holes 62 and 68 in the die holder 60 and retainer 66, respectively, should have diameters which are large enough to permit unobstructed movements of the wire rod 10 and wire 12. A fluid circulation chamber or vessel 70 carries a guide piece 72 extending vertically through a bottom wall of the vessel 70 and having an upper end which is lower than the rim of the vessel as illustrated. The guide piece 72 has a vertical bore 74 which also is so sized as to allow unobstructed passage of the wire rod 10 or drawn wire 12. The vessel 70 is in communication througha conduit 78 with a source (not shown) of a suitable liquid such as a lubricating oil so that the lubricating oil is constantly fed into the vessel 70 as indicated by reference numeral 80. The die asssmbly including the die block 18 and die holder 60 thus floats on the lubricating oil 8(lconstantly stored in the vessel '70 in a manner that the guide piece '76 projects at its upper portion into the lower hole 64 in the die holder 60. Where the wire is drawn upwardly as indicated by an arrow in full line, a piece of cloth 76 or any other meshed member may be immersed in the lubricating oil 80 so that the wire rod 10 to be drawn extends through the cloth 76 and oil is thus applied thereto by the capillary action of the cloth before the rod reaches the die I4. The wire rod 10 is prevented from being directly exposed to the lubricating oil by not only this cloth 76 but the bored guide piece 72 which is isolated from the lubricating oil 80 with its top end closely wrapped by the cloth 76 as seen in the drawing. Provision of the guide piece 72 and cloth 76 is thus useful for preventing the wire rod 10 from being supplied with an excess amount of lubricating oil. An excess amount of lubri- -cating oil would be passed along the drawn wire 12 to guide pulleys and draft rollers and cause the wire to be broken as it is pulled away from the die 14. The lower hole 64 in the die holder 60 should thus be so sized as to allow unobstructed movement of the die holder in a horizontal plane and to readily receive therein the top and portion ofthe guide piece 72 and the cloth 76. The quantity of the lubricating oil applied to the wire rod 10 may be controlled by varying the mesh size of the cloth 76 or any meshed member.

The vessel 70 is fast on a suitable stationary member 32 in a manner that the guide piece 72 is maintained in a vertical direction. 1

Where the wire rod 10 is upwardly fed to the die 14 through the vertical bore 74 in the guide piece 72 and the drawn wire 12 pulled upwardly from the die 14,

. indicated by the arrow in full line, the die assembly is subjected to upward forces resulting from the drawing force on the wire 12 or the axial load on the wire rod 10 and the buoyancy of the die holder 60 and to a downward forceresulting from the total weight of the die assembly, viz., the weights of the die 14, die block 18, die holder 60 and retainer 66. If, in this instance, the buoyancy of the die holder 60 is balanced with the upward drawing force on the wire minus the downward force resulting from the total weight of the die assembly, then the die assembly will be maintained at a standstill with the central hole in the die 14 aligned with the direction of advancement of the wire rod 10 and drawn wire 12. In this condition, the die holder 60 serving as the pressure-receiving member and accordingly the die 14 are constantly maintained perfectly horizontal even if the vessel 70 is not positioned horizontal. If it happens that the wire rod 10 or wire 12 deviates from the predetermined vertical direction in which it is being fed upwardly, then the die assembly floating on the lubricating oil 80 in the vessel 70 is ready to move to a position bringing the axis of the die hole into alignment with the directions of advancement of the wire rod 10 and wire 12.

The amount of weight of the die assembly and the buoyancy of the die holder 60 should be so selected that the former is larger than the latter insofar as the wire is drawn upwardly as discussed above. Where, however, it is desired that the wire is drawn downshould be smaller than the buoyancy of the die holder .60 so that the buoyance of the die holder is substantially equalized with the downward forces resulting from the drawing force on the wire and the weight of the die assembly. In this instance, the wire drawing apparatus may preferably be provided with suitable means for lubricating the wire rod entering the die hole from above the die assembly.

In whichsoever manner the wire drawing apparatus of the construction above described may be used, the die assembly is capable of sensitively responding to a horizontal force applied thereto because thedie assembly is maintained in the balanced position by means of the buoyancy of the die holder 60. The wire drawing apparatus shown in FIG. 5 is therefore adapted especially for the purpose of drawing wires with limited forces and preventing the wires from being broken as they are being pulled from the wire drawing die.

It will now be appreciated from the foregoing description that the method andapparatus herein proposed are of significant advantage for the production of drawn wires which are free from curls and kinks and for preventing the wire drawing die from being subjected to irregular or localized friction and load during operation. If, moreover, the weight and dimensions ofthe die assembly in the embodiment shown in FIGS. 4a and 4/1 or in FIG. 5 are so selected as to produce in the drawn wire a tension which is to be produced in subsequent production steps such as enamel coating or electroplating, then the existence of foreign substances or cavities in the wire may be detected through breakage of the wire during the drawing operation so that troubles that would be encountered in the subsequent production steps can be avoided.

Where it is strongly desired to prevent breakage of a wire during drawing operation, an appropriate arrangement may be added to the wire drawing apparatus according to the present invention so that the wire drawing operation is terminated in an automatic fashion in the event the die assembly has moved excessively away from the fluid circulation chamber.

We claim:

1. A method of drawing a wire, comprising the concurrent and continuous steps of downwardly advancing a wire rod' in a substantially straight vertical path toward a movable constriction having a predetermined diameter and a central axis which is substantially in line with said path of the wire rod, forcing the wire rod through said constriction for contracting the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diameter of said constriction, downwardly pulling the drawn wire from said constriction in a substantially straight vertical'path which is substantially in line with the central axis of said constriction, and directing a fluid upwardly and substantially uniformly onto a horizontal pressure-receiving member having a predetermined amount of weight and movable with said constriction in any direction for imparting to the pressurereceiving member a lifting force sufficient to maintain the pressure-receiving member in a substantially float ing condition.

A method of drawing a wire, comprising the concurrent and continuous steps of upwardly advancing a wire rod in a substantially straight vertical path toward a movable constriction having a predetermined amount of weight and a central axis which is substantially in line with said path of the wire rod, forcing the wire rod through said constriction for contracting the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diforce applied to the wire rod whereby the pressure-' receiving member is maintained in a substantially floating condition relative to the wire and wire rod.

3. A method as set forthin claim 2, in which said fluid under pressure is ejected downwardly onto said pres sure-receiving member for establishing a downward pressure acting on an upper face of the pressurereceiving member so that said downward force is imparted to the pressure-receiving member.

ter and -a central axis which is substantially in line with said path of the wire, forcing the wire rod through said constriction for contracting the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to said diameter of the constriction, upwardly pulling the drawn wire from the constriction in a substantially straight vertical path 3 whichis substantially in line with the central axis of the constriction, and directing a fluid upwardly" and substantially uniformly onto a horizontal pressurereceiving member having a predetermined amount of weight and movable with said constriction in any direction for imparting to the pressure-receiving member a lifting force which is substantiallylarger than a differential between the amount of weight of the pressurereceiving member and a drawing force applied to the wire rod whereby the pressure-receiving member is maintained in a substantially floating condition relative to the wire and wire rod.

6. A method as set forth in claim 5, in which said fluid is supplied under pressure and ejected upwardly onto the pressure-receiving member for establishing an up ward pressure acting on a lower face of the pressurereceiving member whereby said lifting force is imparted to the pressure-receiving member.

7. A method as set forth in claim 5, in which said fluid is stored in a vessel for floating therein said pressurereceiving member and said constriction by a buoyancy of the pressure-receiving member whereby said lifting force is imparted to the pressure-receiving member.

8. A method of drawing a wire which comprises: v

a. advancing an elongated wire rod in a substantially straight and vertical path longitudinally toward a freely movable die assembly formed with a passage of a cross section smaller than the cross section of said wire rod, I. said passage having an axis substantially in line with said path; b. forcing said wire rod through said passage in a vertical direction while the force of gravity acts on said die assembly in a vertically downward direction, whereby the wire rod is reduced in cross sectional area to a wire having a cross section substantially equal to the cross section of said passage, and a vertical wire drawing force is exerted on said die assembly; c. withdrawing said wire from said die assembly in a substantially vertical direction; and cl. directing a fluid against said die assembly in a direction to exert a vertical fluid force on said die as sembly, a v I l. at least one of said .wire drawing and fluid forces being opposed to said force of gravity,

2. the magnitude of said at least one opposed force being sufficient to keep said die assembly freely floating while said force of gravity, said wire drawing force, and said fluid force are exerted on said die assembly.

9. A method as set forth in claim 8, wherein the other one of said wire drawing and fluid forces is also opposed to said force of gravity.

10. A methodas set forth in claim 8, wherein the other one of said wire drawing and fluid forces is opposed to said one force.

11. Apparatus for drawing wire which comprises:

a. a stationary support;

b. a die assembly freely movable relative to said support under applied forces and subject to the-vertical force of gravity, said die assembly including l. a wire drawing die formed with a passage therethrough, said passage having an axis, and

2. a pressure receiving face perpendicular to said axis;

. b. wire drawing means for axially moving a wire rod through said passage in a substantially vertical direction and for therebyexerting a substantially vertical, associated wire drawing force on said die assembly;

d. nozzle means for discharging fluid toward said face and for thereby exerting an associated vertical fluid force on said face,

1. said nozzle means including; a plurality of nozzles fixedly mounted on said support and directed to ward said face in a vertical direction,

2. at least one of said wire drawing means and nozzle means including means for exerting the respective associated force in a direction opposite to said force of gravity.

12. Apparatus as set forth in claim 11, wherein said wire drawing means include means for moving said wire rod in a substantially vertical upward direction, whereby said wire drawing force opposes said force of gravity.

13. Apparatus as set forth in claim 11, wherein said nozzles are directed toward said face in an upward direction, whereby said fluid force opposes said force of gravity.

14. Apparatus for a. a vessel;

b. a body of liquid in said vessel;

c. a die assembly floating in said liquid, a lifting force being exertedby said liquid on said die assembly and opposing the force of gravity acting on said die assembly,

1. said die assembly including a wire drawing die formed with a passage therethrough, said passage having a substantially vettical axis; and

d. wire drawing means for axially moving a wire rod drawing wire which comprises:

through said passage and for thereby reducing the cross section of said wire rod, whereby a wire drawing force is exerted on said die assembly and op poses one of said lifting and gravity forces.

15. Apparatus as set forth in claim l4, wherein said 5 wire drawing means includes means for moving said wire rod upward through said passage, whereby said wire drawing force opposes said force of gravity.

16. Apparatus as set forth in claim 14, wherein said wire drawing means includes means for moving said wire rod downward through said passage, whereby said wire drawing force opposes said lifting force.

17. Apparatus as set forth in claim 14, wherein the specific gravity of said die'assembly is smaller than the specific gravity of said liquid.

Claims

1. A method of drawing a wire, comprising the concurrent and continuous steps of downwardly advancing a wire rod in a substantially straight vertical path toward a movable constriction having a predetermined diameter and a central axis which is substantially in line with said path of the wire rod, forcing the wire rod through said constriction fOr contracting the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diameter of said constriction, downwardly pulling the drawn wire from said constriction in a substantially straight vertical path which is substantially in line with the central axis of said constriction, and directing a fluid upwardly and substantially uniformly onto a horizontal pressure-receiving member having a predetermined amount of weight and movable with said constriction in any direction for imparting to the pressure-receiving member a lifting force sufficient to maintain the pressure-receiving member in a substantially floating condition.

2. A method of drawing a wire, comprising the concurrent and continuous steps of upwardly advancing a wire rod in a substantially straight vertical path toward a movable constriction having a predetermined amount of weight and a central axis which is substantially in line with said path of the wire rod, forcing the wire rod through said constriction for contracting the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to the diameter of the constriction, upwardly pulling the drawn wire from said constriction in a substantially straight vertical path which is substantially in line with the central axis of the constriction, and directing a fluid under pressure vertically and substantially uniformly onto a horizontal pressure-receiving member having a predetermined amount of weight and movable with said constriction in any direction for imparting to said pressure-receiving member a downward force which is substantially larger than a differential between the amount of weight of the pressure-receiving member and a drawing force applied to the wire rod whereby the pressure-receiving member is maintained in a substantially floating condition relative to the wire and wire rod.

2. a pressure receiving face perpendicular to said axis; b. wire drawing means for axially moving a wire rod through said passage in a substantially vertical direction and for thereby exerting a substantially vertical, associated wire drawing force on said die assembly; d. nozzle means for discharging fluid toward said face and for thereby exerting an associated vertical fluid force on said face,

3. A method as set forth in claim 2, in which said fluid under pressure is ejected downwardly onto said pressure-receiving member for establishing a downward pressure acting on an upper face of the pressure-receiving member so that said downward force is imparted to the pressure-receiving member.

4. A method as set forth in claim 2, in which said fluid under pressure is ejected in the vicinity of a lower face of said pressure-receiving member for establishing a suction underneath said member so that said downward force is imparted to the pressure-receiving member.

5. A method of drawing a wire, comprising the concurrent and continuous steps of upwardly advancing a wire rod in a substantially straight vertical path toward a movable constriction having a predetermined diameter and a central axis which is substantially in line with said path of the wire, forcing the wire rod through said constriction for contracting the wire rod about the central axis of the constriction into a wire having a diameter which is substantially equal to said diameter of the constriction, upwardly pulling the drawn wire from the constriction in a substantially straight vertical path which is substantially in line with the central axis of the constriction, and directing a fluid upwardly and substantially uniformly onto a horizontal pressure-receiving member having a predetermined amount of weight and movable with said constriction in any direction for imparting to the pressure-receiving member a lifting force which is substantially larger than a differential between the amount of weight of the pressure-receiving member and a drawing force applied to the wire rod whereby the pressure-receiving member is maintained in a substantially floating condition relative to the wire and wire rod.

6. A method as set forth in claim 5, in which said fluid is supplied under pressure and ejected upwardly onto the pressure-receiving member for establishing an upward pressure acting on a lower face of the pressure-receiving member whereby said lifting force is imparted to the pressure-receivIng member.

7. A method as set forth in claim 5, in which said fluid is stored in a vessel for floating therein said pressure-receiving member and said constriction by a buoyancy of the pressure-receiving member whereby said lifting force is imparted to the pressure-receiving member.

8. A method of drawing a wire which comprises: a. advancing an elongated wire rod in a substantially straight and vertical path longitudinally toward a freely movable die assembly formed with a passage of a cross section smaller than the cross section of said wire rod,

10. A method as set forth in claim 8, wherein the other one of said wire drawing and fluid forces is opposed to said one force.

11. Apparatus for drawing wire which comprises: a. a stationary support; b. a die assembly freely movable relative to said support under applied forces and subject to the vertical force of gravity, said die assembly including

14. Apparatus for drawing wire which comprises: a. a vessel; b. a body of liquid in said vessel; c. a die assembly floating in said liquid, a lifting force being exerted by said liquid on said die assembly and opposing the force of gravity acting on said die assembly,

15. APparatus as set forth in claim 14, wherein said wire drawing means includes means for moving said wire rod upward through said passage, whereby said wire drawing force opposes said force of gravity.

17. Apparatus as set forth in claim 14, wherein the specific gravity of said die assembly is smaller than the specific gravity of said liquid.