US2114632A - Wire drawing machine - Google Patents

Description

Fild Feb. 27,- 1936 3 Sheets-Sheet 1 WWW,

w. Otho L. Giffi w, C-1W April 19, 1938. o. L. GIFFIN 2,114,632

W'IRE DRAWING MACHINE 7 Filed Feb. 2'7, 1936 3 Sheets-Sheet2 0x110 L. Giffin April 19, 1938. Q G|FF|N 2,114,632

' WIRE DRAWING MACHINE Filed Feb. 27, 1936 3 Sheets-Sheet 5 Patented Apr. 19, 1938 UNITED STATES PATENT OFFICE 12 Claims.

This invention relates to wire drawing machines and more particularly to apparatus comprising a seriesof alternately arranged drawing blocks and dies which are employed for drawing the wire to successively smaller sizes in a continuous operation.

In such an operation, the wire is drawn through a series of dies of successively smaller diameters by means of drawing blocks or drums arranged one for each die and about which several turns of wire are wound so as to give the desired traction. As the wire becomes reduced in diameter and consequently elongated, it must be moved at an increased speed by each successive block in the series. Owing, however, to variations in the dies due to their becoming worn, or to changes in the physical characteristics of the wire itself, it is diillcult to rotate the drawing blocks atspeeds pre-calculated to maintain the wire under a uniform tension between the successive dies. An oversized die will not deliver wire fast enough for the later drawing blocks and may cause breakage of the wire, while an undersized'die will produce wire of greater elongation than required by the next die and block set. The turns of wire about a block will grip it tightly and cause the wire to move forward only if the wire coming off the block is held under tension; but if a given block tries todeliver wire to the next die faster than the die can take it, this tension lets up and the block slips within the turns of wire. The standard practice, necessitated by variations in die size,

has been to rotate each successive block in the series slightly slower than will ever be required and thus to cause the wire to slip on each preceding block to that extent which is needed to keep the wire moving continuously and without accumulating between the blocks. Each of these drawing blocks has several turns of wire around it and the slippage of wire on the block serves to flatten the wire on its under side and to create a high frictional heat, as well as to cut the drum and to remove the lubricant from the wire which is required in the next drawing operation. Owing tothese unfavorable conditions and particularly to the high frictional heat, the speed at which wire can be drawn is materially limited.

Numerous attempts have been made to overcome these diificulties. For example, it has been proposed to drive each rotating drum by a separately controlled electric motor in which the tension of the wire serves to regulate the speed of the motor; but this requires the use of a direct current in a plant which may be equipped only with an alternating current, and it is diilicult to regulate the motors with sufllciently fine accuracy for the purpose. It has also been proposed to accumulate an increasing number of turns of wire on the drawing drum and to pull this wire 5 off the drum in an axial direction as. it is r6- quired by the next drawing die in the series. This wire is coiled in a helical form and when pulled off axially it is necessarily twisted, once for each turn of the wire on the drum. For the softer wires, such as copper, this twist may not be detrimental, but for high carbon steel wire this twist may be highly objectionable and seriously affect the physical characteristics of the product. Other disadvantages are inherent in such prior art constructions.

It is the primary object of this invention to provide a continuous wire drawing machine in which the wire does not slip on the drawing drums and is not flattened thereby and the excessive heat heretofore produced by such slippage is minimized, so that the wire may be drawn at a much higher rate than heretofore feasibleior a given type and size of wire.

A further object is' to provide an accumulator for use between two drawing dies in a series which permits the wire to be delivered by one block at a rate in excess of the requirements of the next die and block set and serves to take up all wire slack between the dies and maintain the wire under proper tension at all times.

A still further object is to provide wire drawing apparatus comprising a series of dies, drawing blocks, and accumulators which will serve in a high-speed continuous wire drawing operation to reduce a given wire or rod to a desired wire size and which will compensate fully for all variations in the die sizes and prevent slippage of the wire on the drawing blocks, although each succeeding block in the series is rotated to draw the wire through a die at a rate which is slower than the rate of supply of wire to its cooperating die. Further objects will be apparent in the following disclosure.

In accordance with this invention, I have provided a wire drawing apparatus in which the wire is moved positively by the drawing blocks or drumsand is. not permitted to slip materially thereon while the wire is drawn through a suecession of dies in a continuous operation. In this series, each block is so rotated by. a positively acting driving mechanism that it delivers the wire to the next die and block set at a rate which is faster than the take-up rate required by that "serves to hold the wire taut.

without it becoming twisted. Moreover, the wire is always held under that tension which is required to maintain the turns of wire tight on the preceding drawing block and thus prevent the wire from slipping thereon. This tension is provided preferably by means of a friction driving mechanism which tends to reel up the wire faster than it is received and thus through slippage The accumulator reel is preferably so constructed that the wire may be continually wound in an increasing number of turns at a rate which depends upon the difference in the rates of delivery of the wire thereto and its being paid out to the next die.

In the preferred embodiments of this invention, the reeling mechanism comprises a series of rotatable rollers and a leading roller whichare revolved axially concentric with a drum about which the wire passes. The drum may be a drawing block, or a freely rotatable drum, as preferred; and the parts are so constructed and arranged that as the reeling mechanism is revolved with its rollers, the leading roller tends to wind the wire on both the outer series of rollers as well as upon the inner drum. During this reeling operation, the wire is permitted to travel freely but under a proper tension at whatever rate is required by the next drum in the series. This tension is furnished preferably by a friction driving mechanism which tends to reel the accumulated wire at a rate faster than it is delivered thereto, and the tension may be regulated as desired. Consequently, the wire may be prevented from slipping on the drawing blocks, although they deliver the wire to the accumulator faster than required by the next die and block sets in the series.

Referring to the drawings which illustrate two embodiments of this invention:

Fig. '1 is a fragmentary perspective and somewhat diagrammatic view of one formof wire drawing machine;

Fig. 2 is a vertical elevation, partly in section and broken away, of a series of two dies and two drawing drums associated with an accumulator for taking up the excess of wire delivered to the second die by the forward drawing drum;

Fig. 3 is a top plan view, partly in section, taken substantially on the line 2--2 of Fig. 2, which is intended primarily for illustrating the operation of the device;

Fig. 4, is a vertical elevation, partly in section, of a modified form of device in which the first 4 drawing drum and accumulator reeling mechanism are combined;

Fig. 5 is a view taken substantially on the line 5--5 of Fig. 4, which shows'the essential parts of the construction and its operation;

Figs. 6 and '7 are respectively a top plan view and section of the friction driving device shown in Figs. 1 and 2; and

Figs. 8 and 9 are respectively a top plan and section of the driving plate which is connected to rotate the accumulator reel.

Referring now to Figs. 1 to 5 inclusive, the wire Hi to be drawn is carried forward through a series of dies II and I2 of any 'suitable construction and mounting by means of two drawing blocks or drums l3 and it, it being understood that this arrangement may be duplicated as many times as is desired and that other apparatus may be readily combined with the parts here shown as is needed in a wire drawing mill. The forward drum l3, which may be considered as a feeding drum, is rotated by any suitable mechanism, such as a power shaft l6 connected through beveled gears l1 and I8 with a shaft l9 keyed to the drum. Similarly the other drum H, or receiving drum is driven by another shaft 20 and a suitable gear mechanism. The speed ofthe second drum I4 is slightly less than that required to take up all of the wire fed to its associated die l2 by the first drum l3. That is, the rate of wire movement at A is always a little less than the rate of wire movement at B. This means that an excess of wire is being fed into the space in advance of the die l2 and must be taken up by some suitable device. For that purpose, I provide the special accumulator reeling mechanism which is the primary feature of this invention.

This accumulator reel may be defined simply as comprising a series of freely rotating rollers 25 which form an outer peripheral surface on which loops of wire may be wound, together with a leading roller 21 which serves somewhat as a finger to so move a loop of the wire that one branch goes around the imaginary cylinder formed by the rollers 25 and the other about an inner drum 28 located axially concentric with the path of revolution of the. rollers. By means of a friction driving mechanism, the leading roller 21 together with all of the' smaller rollers 25 are revolved in the direction of the arrow C so that as this roller 21 moves along its path, it wraps the portion D (Figs. 3 and 5) of the moving wire about the inner drum 28 while it wraps the portion E of the wire about the assembled rollers 25. These rollers and drums may be tapered just as are the drawing drums and I4, in accordance with standard practice, so that the wire may readily slip sideways as is required for continuously winding an increasing number of loops of wire on the accumulator reeling members. The path of wire travel, is shown diagrammatic in the drawings, but it will be appreciated that several turns of wire may be placed about a drawing drum and that the reeling mechanism will start first with but a single loop of wire as indicated in Fig. 5 and then gradually wind up the excess wire in a plurality of turns as indicated in Fig. 3.

The inner drum 28, shown in Figs. 1, 2 and 3, is mounted on ball bearings and rotates freely so as to permit a free forward movement of the wire as required by the next drawing block in the series. In the modification shown in Figs. 4 and 5, the forward drawing block I 3 and the freely rotatable drum 28 of Figs. 1, 2 and 3 are replaced by a single drawing drum 30 which serves the double function of both drawing the wire through the forward die II and feeding it forward to the receiving drum l4 and its die and of providing a surface above which coils of wire may be continuously wound as the accumulator mechanism takes up the slack of wire. In the modification of Figs. 4 and 5, the drum 3!] carries initially a suflicient number of turns of wire thereabout to give the necessary frictional grip and draw the wire through the die H, but, as the leading roller 21 revolves around the draw- 7 features of the invention, it will now be appreciated that many details of construction may be adopted within the scope of this invention. The

drawing drums, dies and accumulator reeling mechanism may be suitably mounted on a support 35 which determines the proper location and alignment of the wire drawing parts. The drums l3 and it will, of course, be suitably supported in bearings (not shown) and the-drums may comprise the usual flanged and tapered con-' struction as is well known in the art, whereby the wire will engage each drum adjacent to the flange portion it and, as it continually wraps about the drum, the loops of wire will be moved laterally across the slightly tapered surface thereof.

The accumulator reeling mechanism may comprise, as shown in Figs. 1, 2 and 4, an annular roller support it carried by arms dd which are in turn integral with a central hub it mounted loosely on but concentric with the shaft iii. The rollers 25 and. it are rotatably mounted on antifriction ball bearings so as to spin freely under the impulse given by the moving wire. One simple form. of construction for this purpose involves providing a lower ring-shaped member it having a set of arms db (Fig. 2) integral therewith and suspended from. the ring dd by means of cap-screws it arranged to secure the parts tostruction. The rollers are shown as having reduced ends mounted within the inner race member of each of the ball bearings. It will also be observed that the ball bearings are mounted in the sockets in the ring'members it and id and that the ends of the rollers likewise project into these soclrets so that the inner faces of the rings will act as ilanges for the rollers and prevent the wire from slipping oil the ends thereof. The larger roller til may be provided with a flange at its lower end to aid in leading the wire around the rollers it. This roller it is preferably mounted with its axis so located that its outer side lies substantially in the circle defined by the loop of wire around the rollers 25 so that the wire will not be bent at this point.

in the modification shown in Figs. 1 and 2, the inner drum it is mountedior tree rotation about the shaft t2. To this end, the 'drum may be mounted on ball bearings bill and. it by means of any suitable construction. For example, the shaft it may be slightly reduced in size, as shown, so as to provide a shoulder forsupporting the lower bearinglii, and this in turn carries the hub iii (Fig. l.) of the drum it which supports the upper set of bearings 50. It will be understood that the inner race member of the ball bearings is mounted on the shaft 42 while the outer member revolves freely with the hub and drum 2d.

The drum 28 is located partly below the rollers 25 and 2? so that it may receive the line of wire coming thereto from the drawing drum l3, as indicated in Fig. 2, without interference from the ring N of the reeling device. This drum is also provided with an upper flange 54 which insures that the turns of wire will not slip ofi the upper end of the drum during the reeling-operation. The accumulator is so constructed and arranged that the wire coming from the first drum. It, as

shown in Figs. 1, 2 and 3, may be mounted by being first wrapped around the freely rotatable drum 2B and then passed up through slot 41 after which it is passed, as indicated by the arrows,

around the leading roller 21 from the inside toward the outside of all of the rollers25 and then back to a pulley or drum 56 which serves to lead the wire to the next drawing die l2 and from which it again passes tothe next drawing block it of the series. The arrows on the wire indicate its direction of movement through the machine while the other arrows indicate the directions of rotation and revolution of the rollers and inner drum during the drawing operation.

As above stated, the rate of wire movement at A is less than the rate of movement at B on the opposite side of the accumulator, so as to take care of any variations in size of the die it and insure that there is always sufiicient wire available for the die as is required by the particular rate of speed given to the drawing block it. The speed of the drawing blocks it and Hi will be, of course,

predetermined in accordance with wire-drawing requirements, it being customary to have the second drum it rotating faster than the drum id because of the further elongation of the wire produced by the die it. But, it is essential in this particular machine that the drum it does not move the wire through the die it as fast as it is delivered by the first drum iii. The gear ratios of the various drawing drums are therefore fixed at such rates that there will always be continuous accumulation of wire on the accumulator reeling mechanism as the wire passes freely through this mechanism from one drawing block to the next. As a specific example of rates of movement of the wire which rates are, of course, to be taken as merely illustrative of the invention, the rate of movement at B may be 240 feet per minute and at A 200 feet per minute. The speed of the wire receiving drum it is predetermined to draw through the die it the wire which is delivered thereto by the feeding drum it at about this speed of 200 feet per minute. These rates serve to deliver 40 feet of wire per minute to the accumulator mechanism,

and the latter must not only reel up that excess of wire but it must also hold the wire under that tension which is required to prevent slippage on the drawing block iii. It is not feasible owing to variations in die sizes and other conditions in the wire drawing operation to rotate this reeling mechanism at that particular speed which would just take up the 40 feet per minute. It is, therefore, desirable that this reeling mechanism comprise a friction drive which tends to wind up the wire faster than it is delivered and so through the slippage of the driving mechanism keeps the wire under a desired but adjustable tension.

This friction driving mechanism may comprisemany embodiments of construction. A simple one is illustrated in Figs. 1 and 2. As there indicated diagrammatically, the shaft it may be rotated by reduction gears 5i and 5d at a much slower speed than the shaft it, but more than suflicient to wind up the accumulated wire. The power from this shaft if is conveyed through a friction drive to the reeling arms 39 and rings 38.

This friction drive may comprise, as indicated in able friction driving material, such as an asbestos lining used for standard friction brakes, is suitably fixed on the inside of these arcuate members 6| and 62. A bolt and spring 65 serve to hold these friction driving members under an adjustable pressure against the drum surface of the plate 60, whereby the tension on the wire may be varied as desired. The driving member 6| has a slot 61 in its periphery (Fig. 6) arranged to receive a post 68 (Fig. 9) on a driven plate 69 located therebeneath. This driven plate is provided with bosses having flat surfaces 10 adapted to support the friction driving members GI and 62 in proper position. The plate 69 is secured by screws or other suitable devices to the hub 40 which is integral with the arms 39 and rings 38 the shaft 42.

of the reeling mechanism. This hub 40 is provided with a bushing and is freely rotatable about It will, therefore, be appreciated that the driving force of the shaft 42 is transmitted through the friction driving band 64 to the plate 69 and thence to the reeling mechanism. Hence, the slow speed shaft 42, which tends to rotate the reeling mechanism too fast to take up the wire slack, serves through the friction drive to revolve the rollers and keep the wire under tension as it moves freely through the accumulator.

In the simplified construction shown in Figs. 4 and 5, the rollers 25 and 21 may be mounted as above described, but the drawing drum 30 is keyed to the shaft 42 so as to be rotated at that speed which is required for drawing the wire through the drawing die ll of the series.

That is, this drum 30 replaces the drum l3 of the construction shown in Figs. 1, 2 and 3. In the form shown'in Fig. 4, the hub 40 of the reeling mechanism is supported on a collar carried by the central hub 15 of the drum 30. The latter is in turn supported on a shoulder on the shaft 42. Various constructional details may be employed for this arrangement.

In the device shown in Fig. 1, the shaft 42 rotates at a comparatively slow speed, while in the modification of Figs. 4 and 5 the shaft 42 must have the speed required for the drawing drum 36. Hence, I have provided a double reduction gear to impart a slow motion drive to the friction driving plate. For this purpose, the upper reduced end of the shaft 42 carries a small gear 16 meshing with a larger driven gear 11 which is keyed on a shaft I8. This shaft is mounted in bifurcated arms 19 of the standard suitably supported on the bench and arranged to hold the shaft 18 and its gears in a definite position. Keyed to the shaft I8 is a further small gear 82 which drives a larger gear 83. The latter is provided with a bushing and is mounted for free rotation about the shaft 42. The gear 83 is shown as integral through an intermediate hub with the driving plate which serves to rotate the driven plate 69 through a friction drive of the same constructional details as are shown in Figs. 6 to 9 inclusive. The gear ratios will, of course, be such as to provide the necessary speed of rotation for the reeling mechanism without too much slippage by the friction driving band, it being understood that the gear ratios shown in the drawings are merely diagrammatic and intended simply to illustrate the principles of the invention.

It will now be understood that as the leading roller 21 moves in the direction of the arrow C, it takes the single loop of wire (Fig- 5) and gradually winds turns of wire about the inner drum 28 or 30 and another set of turns about the outer rollers 25; but owing to the free rotation of all of these rollers and to the movement of the drum 28 or 30, the wire will continue to pass freely through the accumulator mechanism as it is required for the next drawing die l2. Thus the wire goes at a high speed through this reeling mechanism all the while that turns of wire are being wound in duplicate on the inner drum and the rollers 25. Owing to the friction drive, the reeling mechanism is trying to wind the wire faster than it is received and so places a definite but adjustable tension thereupon and holds the turns of wire tight on the preceding drawing drum l3 and will not permit them to slip as would be the case if the wire at any time became loose at the point B. It will also be appreciated that by inter-' posing accumulator devices alternately with the drawing dies in a long series of drums and dies, all of the excess wire between the dies will be taken up and the wire may be drawn continuously within the capacity of the reeling mechanism to accumulate the excess of wire fed thereto.

It is also to be observed that, as the wire passes freely through the reeling mechanism, it is not twisted as would be the case if it were pulled axially off a winding drum and that the wire is not obliged to take any sharp-angled turns in its movement. The leading roller 21 as well as the path of the rollers 25 may be made as large as may be required by the particular type of wire being drawn. It is furthermore to be emphasized that the wire is passing freely through this reeling mechanism all of the time and that it is not wound up in stationary coils on a drum, nor is it restrained in its forward travel by the reeling mechanism. The excess of wire delivered by the first drawing block is reeled onto the accumulator gradually as the wire drawing continues. Then, when the rear end of the wire has passed the first block, it gradually unwinds from the first accumulator and so is drawn through the next die and on through the series.

It will also be appreciated that the mechanism of Figs. 4 and 5 may be applied directly to a drawing block of the type which is standard in commercial use and with but few changes in the existing set-up, except as is required to provide the connections from the shaft 42 to the accumulator reel gear mechanism. In the standard methods as heretofore practiced, each drawing block I4 is always rotated at too slow a rate to take up the wire delivered thereto by the previous drawing block, hence it requires a constant slippage of wire back through the series of drawing blocks from the final block to the first one used in the operation. By incorporating the accumulator reeling mechanisms in that series, the wire is kept tight and there is no slippage on any of the blocks. Consequently, the blocks are not overheated by the frictional slippage, nor is the wire flattened thereby. Hence, it is possible now to draw wire at a much more rapid rate than was heretofore permitted because of that excessive frictional heat. Many other advantages in this construction will be apparent to one skilled in the art.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A wire drawing machine comprising a series of dies and drawing drums arranged alternately for drawing wire in a continuous operation,

' means for rotating the drums in the series at such rates that each drawsthe wire through its associated die at a slower rate than that at which the wire is fed thereto by the preceding drum and causes an accumulation of wire, an accumulator having a reel and mechanism arranged for winding the accumulated wire thereon and paying it out freely as required by the next die, and means including a friction driving device and a reduction speed mechanism driven by the drum rotating means which serves to drive the reeling mechanism and to hold the wire under tension while permitting free longitudinal movement thereof.

2. A wire drawing machine comprising a series of dies and drums arranged alternately for a continuous drawing operation, driving mechanism for the drums which causes an accumulation of wire in advance of a given die in the series, a wire accumulator having a reel mechanism including an inner drum and an outer support for turns of wire axially concentric with the drum which are arranged to receive the accumulated wire and permit a free forward movement thereof as required by the next drawing drum, and means including a friction driving device tending to reel the wire on the drum and the support and hold the wire tight and thus prevent longitudinal slippage of the wire on the next preceding drum of the series.

3. A continuous wire drawing machine comprising a series of dies and positively driven drawing drums arranged alternately as feeding and receiving drums for drawing the wire in a continuous operation, mechanism for rotating the drums at rates which cause each feeding drum to deliver wire faster than the receiving drum requires it and results in an accumulation of wire in advance of a given die, and an accumulator arranged to take up the excess of wire including a reel revoluble to wind wire on both itself and a feeding drum and means including a friction device and a slow speed driving mechanism to revolve the reel and place the wire under tension as it moves freely forward, thereby prevents slippage of the wire on the next preceding drawing drum in the series.

4. In a wire drawing machine having a series of dies and drawing drums arranged for a continuous wire drawing operation which provide an accumulation of wire in advance of a die, an accumulator for the excess of wire comprising an inner drum on which the wire is wound and an outer series of rollers revoluble about the axis of the inner drum which are arranged to receive coils of wire thereon and permit free forward movement thereof, and means including a leading roller revoluble about the drum which is arranged to wind wire on the inner drum and the rollers and thereby continuously accumulate turns of wire as it moves freely forward.

5. A wire drawing machine comprising a series of dies and drawing drums arranged alternately, mechanism for driving a drum in the series which serves to draw the wire through its associated die at a slower rate than that of the wire fed thereto, an accumulator mechanism arranged to take up the excess of wire fed to said die having an inner drum and a series of wire supporting rollers and a leading roller mounted to revolve about the axis of said drum, which are so arranged that the leading roller serves to Wind turns of wire about the inner drum and the outer rollers while the wire is permitted to move freely through the machine, and a friction driving mechanism adapted to revolve said leading roller and the supporting rollers at a rate required to form said turns of wire and to hold-the wire under tension and prevent slippage on a drawing drum in advance thereof.

6. In a wire drawing machine having a series of alternately arranged dies and drawing blocks, an accumulator interposed between two dies comprising a rotatable inner drum, a support revoluble about the axis of the inner drum, a series of wire supporting rollers, including a leading roller, mounted for free rotation on and revolving with said support, which are so arranged that wire received from a die may be wound around the inner drum and then around the leading roller and in a reverse direction about the supporting rollers and thence passed to the next die in the series, and friction driving mechanism adapted to revolve the leading roller and the roller support and wind the wire slowly on the inner drum and about the inner rollers while the wire travels freely around the drum and rollers to the next die.

'7. A machine of the type covered by claim 6 in which the inner drum is positively rotated and serves as a drawing block, comprising driving mechanism for revolving said drum and reduction gear mechanism 'and a friction drive associated therewith which are connected with said driving mechanism and revolve the roller support at a slower rate than the rotational rate of the drum.

8. A machine of the type covered by claim 6 in which the inner drum is freely rotatable independently of the roller support and the wire is fed thereto from a positively rotated drawing block arranged independently of the accumulator.

9. An accumulator for use in a wire drawing machine comprising a shaft, a rotatable drum mounted thereon, a, support mounted to revolve about the drum axis, a series of freely rotatable rollers, including a leading roller, which are mounted on and revolve with the support concentricaily about the drum axis and are so arranged that the leading roller may serve to wind turns of wire on the other rollers and the drum, a friction driving device connected to revolve said support, and means to rotate the driving device.

10. A device of the type covered by claim 9 in which the drum is positively connected to and rotated by the shaft, and reduction speed mechsion on the wire.

OTHO L. GIFFIN.

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