US2208735A - Method and mechanism for drawing wire - Google Patents

Description

y 3,1940. L. SIMONS 2,208,735

METHOD AND MECHANISM FOR DRAWING WIRE Filed Dec. 7, 1939 2 Sheets-Sheet l INVENTOR. F| 3.2. flan/- @am BY WG 'Q MIA/ KATTWORNEYS July 23, 1940. 'SIMONS METHOD AND MECHANISM FOR 'DRAWING WIRE Filed Dec. 7, 1939 2 Sheets-Sheet 2 VINVEIQVTOR. eon .fmafls MJ ga -M ATTORNEYS Patented July 23, 1940 UNITED STATES METHOD AND 2,208,735 I MECHANISM FOR. DRAWING WIRE Leon Simons, New York, N. Y., assignor to Texteel Wire Strip Company, Inc., Bronx, N. Y., a corporation of New York Application December 7, 1939, Serial No. 308,025

I 12 Claims. My invention relates to a new and improved method of wire-drawing and a new and improved mechanism for drawing wire.

One of the objects of the invention is to provide an improved method and an improved mechanism for drawing wire, which can be used in connection with dry drawing or wet drawing, whereby the wire can be drawn in a multiple pass through a gang of dies, the wire being maintained continuously under tension, while it is being pulled through the dies of the gang.

Another object of the invention is to provide an improved method and an improved mechanism for use in wet drawing, whereby a pullmember is located after each die in the gang, while preventing slipping between the wire and the pull-member.

Another object .of the invention is to provide an improved method and an improved mechanism whereby the wire is subjected to a regulated back-pull, during each pass.

Another object of my invention is to provide an improved method and an improved mechanism for drawing fine wire made of stainless steel, and also for drawing the so-called music wire which is used for making springs for valves and for other purposes. I

While the invention applies generally to continuous wire-drawing in a multiple pass through all the dies of a gang, it also applies to drawing the wire through any two adjacent dies of a gang, or through more than twoadjacent dies of a gang. r

Other objects of my invention will be set forth inthe following description and drawings which illustrate a preferred embodiment, it being understood that. the above statement of theobjects of my invention is intended to generally explain thesame without limiting itin anymannerrv Fig. ,1 is a diagrammaticirqn elevation of the improved mechanism. E f 321 -13 29139 w r 3 is a diagrammatic, f ianinstallation which can be used according tomy method. The numerals ;.whic l 1 indicate"th elf. respective torques, and tensions, corre nd to the static equilibrium of the system If 1 i Fig. 4 is a diagrammatic v wwhich shows the common, control, valve' means' fprthe, respective nozzles w i lib r p iv bvdiel 91 01" dies are thus lubricated, the process-is known in the trade as dry" drawing. It is also well-' known to lubricate the dies by means of 3a liquid lubricant and when this type of lubricant is used, the process is known as wet drawing.

In dry drawing, the wire is drawn in a series of single passes. After being pulled through each die, the wire is accumulated upon a reel from which the wire is continuously drawn off, to enter the next die of the gang. The wire is therefore not maintained under tension at the outlet side of each die and it is drawn in a series of single passes.

In the so-called wet drawing, the wire is pulled through each die by means of a pull-drum around whose periphery several turns of the wire are helically wound, so that the pull-drum has a firm frictional grip on the wire. The wire is continuously takenup on each pull-drum and it is continuously drawn off said pull-drum to enter the next gang of the series. In commercial practice, these pull-drums are connected by gears or belts which compel the respective pull-drums to move in absolute unison with each other and at certain relative predetermined speeds. As the 25 wire is reduced, said wire is elongated and the succeeding pull-drums; must therefore have successively greater peripheral speeds. The elongation of a wire as it-lis pulled through a die depends upon the condition of the die., If it has 30 not been made accurately, or if it has become I worn, the reduction of the wire and its elongation will change.

It is impossible to make. practical allowance for this variationin actualpractice, so that when a series of pull-drums are used in fwet. draw ing, the wire .must slip relativeto the'peripheries of the pull-drums. r This slip'is-objectionable' be-L cause it produces objectionable l flats on" the wire;

and to wet drawing. According to my invention, each of the pull-drums is operated by a turbine or turbine wheel. The take-up reel of the system, which can also be considered as a pull-drum, is also driven by an individual turbine wheel. The respective turbine wheels are driven by jets of water or of other liquid, or by jets of gas. Each turbine is driven by its own jet of fluid and these jets preferably have the same velocity. However, the velocities of the respective jets may vary without departing from the invention. The power supply to each turbine is regulated by regulating the volume of fluid which is delivered by each jet, or the velocity of the jet, or by varying both the velocity and volume of the jet.

Figs. 1 and 2 show the last two dies l and 2 of a gang or series of five dies. The entire gang of five dies is shown diagrammatically in Fig. 3. The wire is pulled through the third die lc of the gang by means of the pull-drum 3 which is mounted on the shaft 6, which is driven by the turbine 9. The pull-drum 3 has a sufficient number of turns of the wire W helically located thereon in a layer of single thickness, so as to provide a firm frictional grip between the periphery of the pull-drum 3 and the wire W, so as to eliminate slipping, or at least any substantial slipping of the wire relative to the pulldrum. Whenever I refer to a pull-drum, I include every other type of pull device. The wire W is pulled through the fourth die I by means of the pull-drum 4, whose shaft I is driven by means of the turbine ID. The wire is pulled through the fifth die 2 by means of the reel 5, whose shaft 8 is provided with a turbine H. Each of the pull-drums has the wire located thereon helically and in a single layer and with a sufiicient number of turns, so as to prevent slipping of the wire, or any substantially slipping. The reel 5 has a draft-periphery on which the wire is located as above mentioned, in a helical layer of single thickness. The wire is accumulated above said draft-periphery in the usual manner.

The turbines 9, l0 and H are supplied with respective jets of actuating fluid through the respective nozzles l2, l4 and I5. The fluid may be water or any other liquid, or any gas. As a practical example, the fluid may be water which has a nozzle velocity of substantially 1000 feet per minute. Each of the pull-drums of the entire gang or series has its individual turbine wheel. The respective jets of water may have the same velocity and diiferent volumes, or they may vary in velocity and have the same volume, or they may vary both in volume and velocity. The turbines are of equal pitch diameter and the rims of the pull-drums are of equaldiameter. These factors may be varied. The draft portion of the periphery of the reel 5 preferably, but not necessarily, has the same outer diameter as the rims of the pull-drums. The wire is preferably, but not necessarily, maintained in straight form while it is being reduced, save where the wire is wound helically in a plurality of turns around the respective pull-drums and the draft-periphery of the reel. The wire is maintained under tension continuously from the outlet side of the first die to the reel.

The theory of the invention is best explained by reference to a practical example, which is given merely by way of illustration, and without" limiting the invention.

The pitch diameter of each turbine wheel is nine (9) inches and the outer diameter of the periphery of each pull-drum and of the draftperiphery of the reel 5 is six (6) inches. It is assumed that the invention is applied to reducing wire from an initial diameter of 0.018 inch (18 mils) to a final diameter of 0.010 inch (10 mils). This can be done by a gang of dies which may vary in number from five dies to ten dies. It will be assumed that five dies are used in the gang. The first die la will reduce the wire from an initial diameterof 0.018 inch (18 mils) to 0.0159 inch. The second die lb will reduce the diameter of the wire from 0.0159 inch to 0.0141 inch. The third die lc will reduce the diameter from 0.0141 inch to 0.0126 inch. The fourth die I will reduce the diameter from 0.0126 inch to 0.0112 inch. The fifth die 2 will reduce the wire to its final diameter of 0.010 inch or ten mils.

This is according to the Browne 8; Sharp (B & S) reduction gauge.

The above wire is stainless steel wire and the .respective pulls which are exerted at theoutlet ends of the respective dies are about 1 lb. per mil of diameter of the wire which leaves the respective die, if the wire is stainless steel or the like.

In drawing. the so-called .music wire which is not made of stainless steel and which is made of material which is harder and stronger than stainless steel, the percentages of reduction will differ from those above given. In drawing music wire, the reduction would beaccording to the standard gauge of the American Steel and Wire System. Likewise, in drawing music wire or similar material, the respective pulls which are exerted at the outlet ends of the respective dies are about 1.5 lbs. per mil of diameter of the wire at the outlet side of the respective die.

As an illustration, and taking the example above given with reference to stainless steel, the respective pulling forces which must be exerted at the outlet sides of the respective dies in order to overcome their internal resistances are respectively about sixteen pounds, fourteen pounds, twelve pounds, eleven pounds, and ten pounds. These figures are not exact as they may vary in accordance with the character of the wire, whose hardness and composition may vary from point to point. Likewise, one bundle of wire will differ from another bundle of wire, even though they are supposed to be of the same composition. Therefore, the figures above given are only approximate and the invention is not limited thereto. Likewise, there are numerous different draft systems which are in use by various mills, so that the above example is given only by way of illustration.

The system stated in the above example would have four pull-drums and a reel, which operates as a fifth pull-drum.

Each of the nozzles l2, l4 and I5 has its own regulating valve, which can regulate the pressure and velocity of the respective jet of liquid, gas. steam, etc. Likewise, each turbine can have a pair of nozzles, so that the nozzle l5 has a companion nozzle lie, the nozzle H has a companion nozzle Ha, and the nozzle l2 has a companion nozzle 12a, etc. The jets which are delivered by the associated nozzles 15 and We may strike vanes or blades of the turbine II which are apart. The angle between the points at which said jets operate may be varied as desired. The

companion nozzles Ha, Ma and l2a preferably have no regulating valves, so that the regulation of the power which is supplied to each turbine is adjusted by regulating one of the nozzles of each associated pair. Each turbine may have only one nozzle or it may have more than two nozzles.

In drawing finestainless steel wire of the type above mentioned,the wire is pulled through the last die 2 at a rate of about 300 feet per minute. In drawing music wire, which is a high-carbon steel wire, the wire is drawn through the last die 2 at a speed of about .100 feet to 200 feet per minute. Since the draft-peripheries of the drums and of the reel are of equal diameter, the shaft of the reel 5 will turn at higher angular velocity than the shaft of the pull-drum 4. Likewise, each pull-drum will turn at higher angular velocity than the preceding pull-drum, since the wire is successively elongated as it is pulled through the respective dies.

The back-pull which is exerted at the inlet side of each die may vary as desired, but ordinarily it should be from about 25% to 50% of the forward pulling force which is exerted at the outlet side of the respective die.

The sum of the back-pull and of -the die pull which is exerted upon the wire in a respective die, should not exceed 75% of the breaking force of the wire at the outlet side of the respective die. The forward pull is equal to the sum of the back-pull and the die pull.

During the operation of the mechanism, part of the torque which is applied to each pull-drum which is anterior the reel, results from the pulling force which is exerted through the wire by the next succeeding drum. Therefore, the wire will not slip relative to the draft-devices, either in Wet drawing for fine stainless steel wire and other fine wire, including music wire. Dry drawing is used in drawing heavier wire.

The improved mechanism and method also make automatic allowance for the wear of the dies. As a die becomes worn, it will deliver wire of a heavier gauge and of less elongation. The next succeeding drum or drums will therefore turn more slowly and the circumferential velocity of the respective turbine will be simultaneously diminished. The turbine or turbines whose speed has been diminished will then take up more power or force from the associated jet or jets, even though the regulation of the supply of fluid is not changed. Since the driving force is applied by the last drum or capstan E, the increased force thereon will speed up'all the capstans and their turbines, thus simultaneously diminishing the force applied on each turbine.- The improved mechanism and method will also make automatic allowance for variations in the composition of the wire.

The weight of each drum, including its turbine and other rotating parts, preferably depends upon the thickness of the wire. In the practical example above given, in which stainless steel wire was drawn to a final diameter of 0.010 inch, and

where the pull on the wire at the outlet side of the last die 2 is about ten pounds, the weight of a draft-drum, including its shaft, turbine, etc., will be about ten pounds, although this may vary. If heavier wire is being drawn, the weight of each rotating draft-device will be increased, and finer wire will require the use of lighter draft-devices. Theoretically, the draft-drums should be of minimum weight, so as to have a minimum flywheel effect, and to have maximum sensitiveness Likewise, the wire may be kinked in spots, so

that the pull which is required to pull the wire through a die may vary at spaced points.

I therefore provide just enough fiy-wheel effect to take care of these hard or kinked spots, and

said fly-wheel effect is preferably a minimum.

The valves which are usedin the respective nozzles l2, I4 and I5 can be pressure-reduction valves of any suitable type, so as to control the pressure and velocity of the liquid or gas or vapor which is delivered from said nozzles.' Said reduction valves can be of the familiar needlevalve type. The main valve which regulates the supply of liquid or gas to all the respective nozzles can also be of any familiar pressure-reducing type, so as to control the pressure of the fluid' which is delivered to the nozzles. When the main valve is opened, the water or other fluid, such as air, steam, etc., is supplied under greater pressure and at higher velocity to the turbines, thus increasing the power which is delivered by each nozzle. The force which is actually applied to the turbine by each jet depends upon the velocity of rotation of the turbine.

A turbine which is actuated by a jet of fluid is much superior for the specific purposes of this invention, than any other type of motor. The

. regulation of the jets of fluid can be very precise tion, if the volume and pressure of the respective jet of fluid is maintained constant.

The wire is wound in a sufiiciently large number of turns around each drum, so that a very slight tension of the wire in advance of'the drum will be sufficient to bind the wire frictionally to the drum, thus preventing slipping.

Whenever I refer in the claim or claims to the use of the improved method or mechanism in a connection with a pair of dies, the invention ap-' plies to a system which includes more than two dies. As previously stated, the invention may be used in connection with all the dies of a gang or series, or in connection with only two of said dies, or more than two dies. For convenience, reel 5 may be designated as a pull-drum or draftdevice.

Whenever I refer to independent forces being exerted upon the respective drums, I refer to individual drives for the respective drums, preferably by turbines, in distinction to mechanical driving: interconnection by means of belts or gears or the like.

The shafts 6, I, and 8 are mounted in bearing Ba.

The principle of the invention is explained with reference to the foregoing example, although the percentage of reduction may'vary, and said percentage-may differ from pass to pass.- The'invention is therefore not limited in any manner to the disclosure of said example. In" the foregoing example, the percentage of reduction in the diameter of the wire is about ten percent in each step. The cross-section of the wire is decreased about twenty percent in each pass, and the wire is elongated about twenty percent in each pass.

For convenience, the four pull-drums and the reel of the apparatus are designated in Fig. 3 as members A, B, C, D, E. The. pull-drums 3 and l back-pull of one pound is desired at the inlet end of the finishing die 2, the torque of the turbine of member A is adjusted until the turbine of member A exerts a pull of only twelve pounds on the wire. A pull of four pounds on the wire after member A, plus the pull exerted by the turbine of member A, will exactly balance the internal re- I sistance of sixteen pounds of the first die. After reaching a very low speed, which is about twenty feet per minute, the force which is required to pull a wire through a die does not increase when the speed of the wire is increased, within commercial limits. Likewise, when the device is operating,'aback-pull reduces the effective internal resistance of a die. The wire is now led through the second die lb, wound around member B, and the torque of the turbine of member B is adjusted until member B exerts a pull of fifteen pounds upon the wire. The turbine torque of member A is less than the internal resistance of the first die la, and the turbine torque of member B exceeds the internal resistance of the second die lb, especially since said internal resistance is diminished by the back-pull, when the apparatus is operating at commercial speed.

If the wire in rear of member B is subjected to a pull of three pounds, the wire can be pulled through the first two dies by very slight additional force so as to start the apparatus.

While the apparatus is stationary, the wire between member A and the inlet side of the second die is under a tension of four pounds. The three-pound pull on the wire behind member B and the turbine torque of memberB exert a total pull of eighteen pounds, fourteen pounds of which is taken up by the internal resistance of the second die lb, when the apparatus is stationary. This tension-of four pounds betweenmember A and the second die lb, plus the twelve pound turbine pull of member A, balances the internal resistance of the first die la, when the device is stationary. The wire is under a tension of sixteen pounds between member A'and the first die la, and under a tension of fourteen pounds between member B and the second die lb.

The wire is now led throughcthe third die la and said wire is wound helically around member C (pull-drum 3). The turbine torque of member C is adjusted to produce a pull of thirteen pounds, which exceeds the internal resistance of twelve pounds of the third die lc, when the device is stationary. If the wire behind member C is subjected -to a pulling force of two pounds, as

for example by hand, the mechanism will be in unstable staticequilibrium, because said pull of two pounds, plus the sum of the three respective turbine torque pulls of twelve pounds, fifteen pounds,fand thirteen pounds, will balance the sum of the three internal'die-resistances of sixteen pounds, fourteen pounds and twelve pounds.

'Thewire between member B and'the third die lc will be under a tension of three'pounds. The

wire is now led through the fourth die I, and

and the reel correspond respectively to memwound around member-D (pull-drum 4). The turbine torque of member D is adjusted to exert a pull of 12 lbs. If it is assumed that the wire behind member D is subjected to a pull of one pound, as for example by hand or any suitable 5 mechanism, the mechanism will be in unstable equilibrium and the wire between member C and the fourth die I will be under a tension of two pounds.

The wire is now led through the fifth die 2, and it is wound around the draft periphery of member E (reel 5). The turbine torque of member E is adjusted to produce a pull of eleven pounds. The system is now in unstable static equilibrium. The wire between member D and the fifth die 2 is under a tension of one pound.

The sum of the pulls of the respective turbines balance the sum of the rated internal resistances of the respective dies. Each turbine, with the exception of the first turbine of member A, exerts back-pulls at the inlet sides of the respective dies,

with the exception of the first die, and beginning at the last die 2, are one pound, two pounds. three pounds, and four pounds. The thicker parts or runs of the wire have the greatest backpulls. The back pulls are thus secured before starting the apparatus, by regulating the torques of the respective turbines.

These figurescan be greatly varied, and they are given only by way of illustrating a broad general principle.

The turbine torques of members AE are adjusted by regulating the velocity of one or more jets which strike the blades of the respective turbines. Each turbine can be driven by one jet or by any number of jets, and one or more jets of each group can be provided with pressure regulating valves. As shown diagrammatically in Fig. 4, the nozzles l2, l4 and I5 are connected to a pipe l9, by means of respective. valves l6, l1 and I8. The nozzles l2a, Ma and l5a are connected to a pipe l9a by means of respective valves l6a, l'la and Illa. The pipes l9 and I90 are connected to a common inlet pipe 20, through a common valve 2].

In order to start the mechanism, the turbine torque of member E is slowly increased until member E exerts a small additional pull,'such as an additional pull of one pound for example. This can be done accurately and slowly. The power regulation of the turbines of members AD remains unchanged while the torque of member E is thus increased.

This additional pull will increase the backpulls behind the fifth, fourth, third and second dies, respectively to two pounds, three pounds, four pounds and five pounds.

This excess pull of member E is transmitted by the wire to all the members AD. The members AE will rotate at increasing speed, until their respective turbine torques have diminished due to their rotation. The sum of the torques of members A--E will move the wire at low constant speed through the gang of dies. Since member E will rotate most rapidly, it will suffer the greatest loss of turbine torque, and the loss of turbine torque will diminish successively in members D, C, B, A.

The main valve 2| which simultaneously controls the supply of fiuid through the common inlet 'pipe 20 to all the nozzles is then opened to increase the pressure of the driving fluid, and

each of the other turbines in increased by the same percentage. Before the system is operating at commercial speed, or while it is operating at commercial speed, the power supply to the respective turbines may be adjusted, in order to regulate the back-pull in each run.

The jets can be precisely and accurately regulated so as to vary the back-pull as desired.

Since part of the power of each pull-device is supplied by the succeeding pull-device through the wire, each pull-device must turn in absolute unison with the wire, thus preventing or diminishing any objectionable slipping. This causes self-regulation of the speeds of the drums, if one or more of the dies wear, thus diminishing the reduction and consequent elongation of the wire.

Prior to starting the apparatus, the pull of the turbine torque of each pull-member, with the exception of the first member A, exceeds the rated internal resistance of the respective preceding die. The total pull which is exerted by the members AD inclusive is insufficient to pull the wire through the dies la, lb, lo and I.

The starting force is secured by giving the last pull-member E sufiicient force in excess of the internal resistance of the fifth die 2, said excess force being transmitted through the wire to the anterior pull-members. When the apparatus is operating at commercial speed, the same conditions prevail, and the apparatus is maintained in operation by the excess pull which is transmitted through the wire from the last pull-mem- 'ber E, substantially equally to the preceding pullmembers.

While the forces which operate the respective turbines are controlled by a common valve, said forces are designated as independent, forces, in distinction from forces which are applied by gears, belts, and other forms of mechanical connection between the pull-devices.

The speed of rotation of each pull-drum is governed wholly by the elongation of the wire which is produced by the preceding dies, when the last run of the wire is moving at a constant speed:

Each pull-device is subjected to a direct torque by its own turbine. Each turbine which succeeds the first turbine, exerts'a pull on'the wire, so as to exert a second torque directly on the next preceding pull-device.

The wire in front of the first die la is not subjected to a back pull.

The invention is not limited to any particular type of turbine. While the apparatus is running, the back pull in each run of the wire can be readily measured, and said back-pull can be easily and simply regulated while the apparatus is running, by adjusting the velocity of the jet or jets.

in thespecific disclosure herein, without departing from the spirit of the invention.

The jet or jets preferably have high velocity in comparison withthe velocityof the turbine blades, when the apparatus is running at commercial speed. 5

If water jets are used, they may have a velocityof one thousand feet per minute or even higher. If the wire is pulled through the last die at a rate of 300 feet per minute, the blades of the Numerous changes and omissions can be made last turbine will move at a velocity of 450 feet per minute, since the pitch diameter of the tur-' bine exceeds the diameter of the respective draft periphery by fifty percent. This may be taken as one working example, but the invention is not limited to any particular relation between the velocity of the jet or jets and the velocity of the turbine blades.

Whenever I refer in the claims to a series of dies, I include every system in which the capstans or other pull-members are operated according to the invention, to supply back pull at the inlet ends of two or more dies of the gang of dies.

I claim:

1. A method of starting wire-drawing apparatus which comprises a series of dies and a rotatable frictional pull-device which is located after each die, which consists in applying a torque to the first pull-device which is insufficient to pull the wire through the first die when the wire is stationary, applying respective torques to the other pull-devices in excess of the respective forces required to pull the wire through the respective dies when the wire is stationary, the sum of the pulling forces exerted by the respective torques being insufficient to start the apparatus when the wire is stationary, and supplying excess torque to the last pull-device to start the apparatus.

2. A method of starting wire-drawing apparatus which comprises a series of dies and a rotatable frictional pull-device which is located after each die, which consists in applying torques to said pull-devices so as to produce a back-pull on the wire in front of each die with the exception of the first die while the wire is stationary, said back-pulls decreasing from" the second die to the last die while the wire is stationary, the torques of the pull-devices anterior the last pull-device being insuificient to pull the wire through the corresponding dies; and then applying sufiicient torque to the last pull-device to start the apparatus.

3. A method according to claim 1 in which the torques are produced by the impact of jets of fiuid.

4. A method according to claim 2 in which the torques are produced by the impact of jets of fluid.

5. A method of drawing wire through a series of dies under back-pulls which are applied to the wire anterior the inlet ends of said dies, which consists in applying said back-pulls by exerting the impact forces of moving bodies of fluid upon turbine members which are coupled to the wire and which are actuated by said impact forces together with the wire, topull the wire.

6. Wire drawing apparatus comprising a series of dies, capstans located between the dies and respectively frictionally coupled to the wire between successive dies, said capstans having respective actuating turbine motors, said capstans and their turbine motors having sufficiently low moments of inertia to remain frictionally coupled to the wire without substantial slip under a change in the speed of movement of the wire.

7. Wire drawing apparatus comprising a series stan located after the last die, said capstans being frictionally coupled to the adjacent portions of the wire, said capstans having respective actuating turbine motors, said motors having respective means for supplying bodies of motive fluid thereto, said turbine motors having a common control for-their. respective bodies of motive fluid, the

respective turbine motors also having individual.

controls for their respective supplies'of motive fluid.

8. Wire drawing apparatus comprising a series of dies, turbine-driven capstans adapted to apply respective back-pulls to the wire at the inlet ends of the dies, means for applying torques by motive fluid to saidturbine-driven capstans, said torques increasing when the speeds of rotation of said capstans are decreased, said torques decreasing when said speeds are increased, said capstans being frictionally coupled to respective adjacent parts of the wire.

9. A method of drawing wire which consists in pulling said wire through a series of dies by means of respective turbine-actuated capstans which are frictionally coupled to the adjacent parts of the wire and which are located respectively behind the respective dies, and while maintaining the wire under back-pull between each capstan and the next succeeding die by regulating the torque on each capstan, which consists in turning said capstans by the impact of motive fluid on the respective turbines of said motors so as to apply respective torques to said capstans which increase when the rotative speeds of said capstans are lowered and which torques decrease when the rotative speeds of said capstans are increased.

10. A method of drawing wire through a series of dies under back-pulls which are applied to the wire anterior the inlet ends of said dies, which consists in applying said back-pulls by exerting the impact forces of moving bodies of fluid on turbine-actuated members which are coupled to the wire, causing each said member to change in speed in substantial unison with the respective coupled portion of the wire, pulling the wire through the last die by a last turbine-actuated member which is operated by the motive force of a moving body of fluid, and causing said last member to move in substantial unison with the respective coupled portion of the wire, all said members being free to change in speed in unison with changes in the speedof the wire which is fed thereto.

1 1. Wire-drawing apparatus comprising a series of dies, a pull-member located between each pair of succeeding dies, a final pull-member located after the last die, each said pull-member being coupled to a respective adjacent portion of the wire, turbine-actuated means operated by the impact'of moving fluid and adapted to operate all said pull-members, each pull-member being free to vary in pulling speed in unison with the speed at which the respective portion of the wire is fed'to the respective pull-member, the total force on said actuating means varying inversely to the speed of movement of the last pull-member.

12-. Wire-drawing apparatus comprising a series of dies, turbine-actuated pull-members located between each pair of succeeding dies, 9. final turbine-actuated pull-member located after thelast die, each said pull-member being coupled to a respective adjacent portion of the wire, the pulling force of the first pull-member being less than the internal resistance of the first die, the pulling force of every other pull-member exceeding the internal resistance of the next preceding die, said relation between said pulling forces and said in-' ternal resistance being in effect when the wire is stationary and also when the wire is moving, said forces on the pulling members being. regulated to produce successive anterior back-pulls on the wire anterior the respective dies, with the exception of the first die, said anterior back-pulls decreasing 'from anterior the second die to anterior the last die.

LEON SIMONS.

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