US3402587A

US3402587A - Wire drawing apparatus

Info

Publication number: US3402587A
Application number: US540286A
Authority: US
Inventors: Philip E Lawler
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1966-04-05
Filing date: 1966-04-05
Publication date: 1968-09-24
Anticipated expiration: 1985-09-24

Description

Sept. 24, 1968 P, E.LAWI ER 3,402,587

WIRE- DRAWING APPARATUS Filed April 6. 1966 3 Sheets-Sheet 1 s: 240.. 28 a6 27 f 7 Bin. 34 -F/c; E

p 56 w a g 3 24 a6 a? 36 J lNVENTOR I F .E.\.AW\.EE

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ATTORNEY P. E. LAWLER WIRE DRAWING APPARATUS Sept. 24, 1968 Filed April 1966 3 Sheets-Sheet? Filed April 5, 1966 7 Sept. 24, 1968 P. E. LAWLER 3,402,587

' WIRE DRAWING APPARATUS 3 Sheets-Sheet 5 United States Patent 3,402,587 WIRE DRAWING APPARATUS Philip E. Lawler, Papillion, Nebn, assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed Apr. 5, 1966, Ser. No. 540,286 4 Claims. (Cl. 72-285) ABSTRACT OF THE DISCLOSURE Wire drawing apparatus includes a die support slidable laterally with respect to an advancing wire and a wire drawing die mounted in a spherically shaped seat of the die support and universally movable in response to lateral forces exerted on it by the wire as the wire passes through a bore in the die. The universal mounting of the die in the spherically shaped seat is such that the initial point of contact of the advancing wire with the die is below a plane defined by transverse swivel axes of the die. Thus, the wire continually passes through the die coincident with the longitudinal axis of the bore and in a smooth and uniform manner.

This invention relates to wire drawing apparatus, and more specifically to wire drawing apparatus in which a wire drawing die is capable of universal movement during a Wire drawing operation.

In the manufacturing of wire for communication purposes, it is standard practice to advance wire continuously from a source of supply into a wire drawing machine which reduces the wire to a desired diameter. In the wire drawing machine, the wire passes around a plurality of idler sheaves and associated capstans, passing substantially vertically through a wire drawing die positioned between each idler sheave and a respective one of the capstans as it travels from the idler sheave to the capstan. As the wire passes through successive ones of the wire drawing dies, however, its diameter is progressively decreased and it becomes progressively elongated. Accordingly, successive ones of the capstans are of increased diameters to accommodate the elongating wire, and thus the paths of travel of the wire through the dies do not lie in the same plane, but extend in directions which are at various angles relative to one another.

Heretofore, since the optimum condition for proper drawing of the wire is for the wire to pass axially through each of the wire drawing dies, each wire drawing die has been slidably mounted on a support surface extending perpendicular to a line extending tangent to the idler sheave and the capstan that the die was located between. Each die was slidable on its support surface so that it could adjust to lateral forces being exerted on it by the wire as the wire travelled through the die, as for example, as a result of outward looping of the wire due to inertia as the wire came off the associated idler sheave, thereby to reduce the tendency for the wire to wear the die unevenly.

In addition, however, the capstans must be reground periodically because they wear unevenly, and when they are reinstalled in the wire drawing machine the directions of the paths of wire travel are changed. To compensate for these changes in the past, suitable shims have been provided on the die support surfaces to change the directions of sliding movement of the dies corresponding amounts.

The above-described arrangements have not proved to be satisfactory for providing proper passage of the wire through the wire drawing dies, thereby producing various undesirable results. For example, in addition to the dies still wearing unevenly, the dies tend to draw the wire unevenly, to make the wire brittle, and to sear the wire,

Patented Sept. 24, 1968 causing the formation of rough spots, such as barbs, in its surface. These various defects in the wire frequently produce Wire breakage and/or make the Wire unsuitable for communication purposes. The uneven wearing of the dies also increases the difficulty of reconditioning the dies for reuse. In this regard, frequently a die is worn so unevenly that reconditioning is impossible and the die must be discarded. Where a die is capable of being reconditioned, generally this can be accomplished only by enlarging and reforming its bore to a larger gage size, and then reinstalling the die in the wire drawing machine in the larger gage position. The net result is a substantial increase in manufacturing costs due to scrapped wire and dies, wire line maintenance, and down time of the wire drawing lines, which normally operate at speeds of several thousand feet per minute.

Accordingly, an object of this invention is to provide new and improved wire drawing apparatus in which uneven Wear of a wire drawing die is substantially elimi nated.

Another object of this invention is to provide new and improved wire drawing apparatus in which certain undesirable features, such as uneven wire drawing, wire brittleness, searing of the wire, wire surface irregularities, and wire breaks, are substantially reduced.

A further object of this invention is to provide new and improved wire drawing apparatus in which a wire drawing die readily can be reconditioned.

A still further object of this invention is to provide new and improved wire drawing apparatus in which a wire drawing die automatically adjusts to a change in the direction of wire travel through the die.

Another object of this invention is to provide new and improved wire drawing apparatus in which the amount of wire which can be drawn with a wire drawing die before reconditioning of the die is necessary, is substantially increased.

In accordance with the invention, a wire drawing die is movable universally in response to lateral forces exerted on the die by a wire as the wire passes through a bore in the die, so that the wire continually passes through the die coincident with the longitudinal axis of the bore and in a smooth and uniform manner.

In a preferred embodiment of the invention, wire drawing apparatus includes a die support slidable laterally with respect to an advancing wire. A wire drawing die is mounted in a spherically-shaped seat of the die support and is universally movable in respone to lateral forces exerted on it by the Wire as the wire passes through the die, and the universal mounting of the die in the spherically-shaped seat is such that the initial point of contact of the advancing wire with the die is below a plane defined by transverse swivel axes of the die.

This invention, together with further objects and advantages thereof, will best be understood by reference to the following detailed description, taken in connection with the accompanying drawings, in which:

FIG. 1 is an elevational view of wire drawing apparatus incorporating the subject invention, in cross section;

FIG. 2 is an enlarged, partial plan view of a part of the wire drawing apparatus, as viewed substantially along the line 2-2 of FIG. 1;

FIG. 3 is a further enlarged, cross-sectional view taken along the line 3-3 of FIG 2;

FIG. 4 is an enlarged partial plan view, similar to FIG. 2, of a modified form of apparatus;

FIG. 5 is a further enlarged, cross-sectional view taken along the line 5-5 of FIG. 4;

FIG. 6 is an enlarged, partial plan view, similar to FIG. 2, of another modified form of apparatus; and

FIG. 7 is a further enlarged, cross-sectional view taken along the line 7-7 of FIG. 6-.

Referring to FIG. 1 of the drawing, it is seen that the illustrated embodiment of the invention is designed for use in a wire drawing machine 11 for reducing the diameter of a wire 12 to a preselected size. Subsequently, the wire 12 is insulated to form an electrical conductor suitable for communication purposes.

The wire 12 is advanced into the wire drawing machine 11 from a suitable source of supply 13 by a plurality of capstans 14 secured to a shaft 16, the shaft being journalled adjacent its ends in side walls of a machine cabinet 17 and being rotatably driven by a suitable power source, not shown.

Upon entering the Wire drawing machine 11 the wire 12 passes over a first one of a plurality of idler sheaves 18 secured to a horizontal shaft 19 journalled adjacent its ends in the side walls of the cabinet 17, and then travels downward through one of a plurality of wire drawing die assemblies 21 to a first one of the capstans 14. After passing about the first capstan 14 the wire 12 travels vertically upward, about a second one of the idler sheaves 18, and then downward through a second one of the die assemblies 21 and about a second one of the capstans 14. The wire 12 continues about additional idler sheaves 18 and their respective capstans 14, and through additional die assemblies 21 in the same manner. Finally, the wire 12 is advanced from the last capstan 14 about an idler sheave 22 and to the right, as viewed in FIG. 1, to a next wire drawing stage (not shown) by a series of capstans in this stage. A flooding mechanism 23 maintains the die assemblies 21 continuously submerged in wire drawing compound during the wire drawing operation, and the capstans 14 continuously pass through a lubricating bath in the lower portion of the machine cabinet 17, in a manner well known to those skilled in the art.

As the wire 12 passes through successive ones of the die assemblies 21, its diameter is progressively decreased and it becomes progressively elongated. Accordingly, as is shown in FIG. 1, the capstans 14 are of progressively increased diameters so as to accommodate the elongating wire 12. Thus, the wire 12 travels through the die assemblies 21 along paths which do not lie in a common plane, but which extend in directions which are at various angles with respect to one another,

As is shown in FIGS 2 and 3, each of the wire drawing die assemblies 21 includes a wire drawing die 24 having a wire receiving bore 24a extending therethrough. The die 24 is retained in a circular recess in a die holder 26 by a clip-type retaining ring 27. Each die assembly 21 also includes an annular seat member 28 having an internal spherically-shaped seat 29 (FIG. 3) in which a spherically-shaped peripheral surface of the die holder 26 is received so that the die holder is swivelly mounted in the seat member for universal movement. Thus, the die 24 is universally movable in response to lateral forces exerted on the die by the wire 12 due to changes in the direction of travel of the wire as it passes through the bore 24a of the die, whereby the wire continually passes through the die coincident with the longitudinal axis of the bore and in a smooth and uniform manner.

In the illustrated embodiment of the invention, the die holder 26 and the seat member 28 are a ball member and an outer member, respectively, of a commercial spherical bearing of a type in which the outer member is a one-piece member swaged or otherwise suitably formed about the ball member, such as the Unibal two-piece spherical bearing manufactured by The Heim Universal Corporation of Fairfield, Conn, with the ball member being suitably modified to receive the die 24 and the die retaining ring 27. In the alternative, the seat member 28 may be of a two part, split construction in which the two parts are held together by suitable securing means, in a well known manner.

The wire drawing die assemblies 21 are carried on a horizontally extending die shelf '31 which is fixedly mounted in the wire drawing machine cabinet 17, and upon which the above-mentioned flooding mechanism 23 is mounted in a well known manner. The seat member 28 of each die assembly 21 is secured by suitable screws 32 (one shown in FIG. 3) to a circular slide 33 which is slidably received in a respective one of a plurality of elongated guideways 34 in the die shelf 31, with the bottom of the slide resting upon an upwardly facing support surface 36 defining the bottom of the guideway. The die holder 26 and the slide 33 of each die assembly 21 are provided with

apertures

26a and 33a (FIG. 3), respectively, and the die shelf 31 includes a plurality of elongated slots 31a opening through respective ones of the support surfaces 36, through which apertures and slots the wire 12 passes as it travels from the dies 24 to the capstans 14.

The slidable mounting of each die assembly 21 provides additional freedom of movement of the die 24 of the assembly in response to lateral forces exerted on the die by the wire 12 as it changes direction during a wire drawing operation, particularly in those instances where the increment of change is relatively great. Further, the circular construction of the slide 33 of each die assembly 21, whereby the slide is free to rotate in its respective guideway '34, also provides additional freedom of movement of the die 24 of the assembly about the axis of the bore 240: of the die.

The seat member 28 of each die assembly 21 is provided wit-h a grease fitting 37, which at an inner end thereof communicates with an annular groove 29a in the spherical seat 29 of the seat member, for lubricating the swivel mounting of the die holder 26 of the assembly in the seat. Preferably the lubricant used for this purpose is relatively viscous and non-Water soluble in nature, so that it will not be washed out of the swivel mounting by the wire drawing compound.

As is shown in FIG. 2, the slide 33 of each of the di assemblies 21 is slidable in its respective guideway 34 in relatively close-fitting relationship with respect to side walls of the guideway, and as is illustrated in FIG. 3, each of the support surfaces 36 extends perpendicular to a line which extends between the respective idler sheave 18 and capstan 14 tangent to the sheave and the capstan. However, the die assemblies 21 could be slidable laterally in the guideways 34, to provide additional freedom of movement of the dies 24, and the support surfaces 36 could extend horizontally, if so desired, as in the embodiment of the invention shown in FIGS. 6 and 7, which subsequently is to be described.

The mounting of each wire drawing die 24 in its die holder 26, and the configuration of the wire receiving bore 24a of the die, is such that the initial point of contact of the wire 12 with the die is below a plane 38 (FIG. 3) defined by the transverse swivel axes of the die. More specifically, depending on the gage size of the die 24 involved, the moment arm between the swivel plane 38 and the initial point of contact of the wire 12 with the die 24 should be such that the die swivels readily in response to lateral forces exerted on it by the wire. For example, with a fourteen gage die 24 and a wire drawing speed of sixtyfive hundred feet per minute, favorable results have been achieved with the initial point of contact between the Wire and the die three sixteenths of an inch below the swivel plane 38. In contrast, when the initial point of contact of the wire 12 with the die 24 is above the swivel plane 38, the wire tends to jam up in the die, instead of the die adjusting itself in response to the lateral forces being exerted on it by the wire as the wire changes its direction of travel during the wire drawing operation.

Operation In operation, the wire 12 is advanced into the wire drawing machine 11 by the power driven capstans 14, passing about the idler sheaves 18 and the capstans, and through the wire drawing die assemblies 21 in succession. Finally, the capstans in the above-mentioned next Wire drawing stage advance the wire 12 from the last capstan 14 about the idler sheave 22 and to the right, as viewed in FIG. 1, to the next wire drawing stage.

As the wire 12 passes through the die 24 of each of the Wire drawing assemblies 21 during a wire drawing operation, the path of travel of the wire changes in direction for various reasons, as for example, as a result of outward looping of the wire due to inertia as it comes off of the respective idler sheave 18, variations in wire line speed, or the wearing of grooves in the respective capstan 14, with the wire becoming entrenched in one of the grooves in the capstan. However, as a result of the swivel mounting of the die holder 26 of the die assembly 21 in the seat 29, together with the slidable mounting of the circular slide 33, the die 24 automatically adjusts in its position in response to the forces exerted on it by the wire 12 as a result of these changes in direction, such that the wire always passes through the die coincident with the longitudinal axis of its bore 24a and in a smooth and uniform manner. Accordingly, various undesirable factors which are prevalent in prior known wire drawing apparatus, such as uneven die wear, uneven wi-re drawing, wire brittleness, searing of the wire 12, and the formation of surface irregularities on the wire, are substantially reduced.

More specifically, it has been found that with the dies 24 mounted for universal movement during the wire drawing operation as above-described, the only affect of the wire 12 on each of the dies is the formation of a uniform pressure ring at the point that the wire initially engages the die, and all that is necessary for reconditioning the die is to polish out this pressure ring, whereupon the die can be replaced in the wire drawing machine in the same or next gage position for reuse. Further, not only is the finished wire 12 of superior quality as compared to that produced by prior known apparatus, but the amount of Wire which can be drawn before the dies 24 must be removed for reconditioning, is substantially increased.

FIGS. 4 and 5 illustrate a modified form of the invention which is useful in instances where a sufiiciently great moment arm between the initial point of contact of a wire 112 with a wire drawing die 124, and a swivel plane 138 of the die, cannot be attained with the embodiment of the invention shown in FIGS. 2 and 3.

In the embodiment of the invention of FIGS. 4 and 5, the wire drawing die 124 forms a part of a wire drawing die assembly 121 and is secured by suitable screws in a recess adjacent the lower end of a vertically extending die holder 126. The die holder 126 is suspended adjacent its upper end in a seat member 128 for universal movement and projects vertically downward through an elongated relatively wide slot 131a in a die shelf 131. The universal mounting of the die holder 126 includes an annular ball member 126' which is force fitted on the die holder and received in a spherically shaped seat 129 of the seat member 128. The seat member 128 is force fitted in a recess in a circular slide 133, and the slide is mounted for sliding movement on a bottom surface 136 of an elongated guideway 134 in the die shelf 131. A grease fitting 137 on the slide 133 extends through the slide and the seat member 128 such that an inner end of the fitting communicates with an annular groove 129a (FIG. 5) in the seat member, for lubricating purposes.

The die holder 126 is provided with a wire receiving passageway 126a in axial alignment with a wire receiving bore 124a of the die 124, and also is provided with a plurality of inclined flushing passages 12611, which extend outwardly and downwardly from adjacent the lower end of the passageway 126a, as shown in FIG. 5. Thus, wire drawing compound applied to the die assembly 121 by a flooding mechanism (not shown) of the same type as the flooding mechanism 23 (FIG. 1), can continuously wash residue material, such as wire particles, from the passageway 126a through the flushing passages 126b, thereby to prevent accumulation of the residue material in the passageway and clogging of the bore 124a of the die 124.

FIGS. 6 and 7 illustrate another modified form of the invention in which each of a plurality of wire drawing die assemblies 221 includes a wire drawing die 224 mounted in a recess in a die holder 226, the die holder having a spherically shaped bottom surface received on an upwardly facing spherically shaped seat 229 of a circular slide 233. The slide 233 is supported in an elongated guideway 234 in a die shelf 231, on a guideway bottom surface 236 which extends horizontally, rather than perpendicularly to a line tangent to the respective idler sheave 18 (FIG. 1) and capstan 14, as in the embodiments of the invention in FIGS. 2-5, and the width of the guideway is such that the slide is capable of lateral sliding movement, as well as longitudinal sliding movement, during a wire drawing operation.

The supporting of the slide 233 on a horizontal surface, rather than a surface extending perpendicular to a line tangent to the respective idler sheave 18 and capstan 14, while placing greater reliance on the swivel mounting of the die holder 226 to maintain proper alignment between the die and a wire 212, is advantageous in that the weight of the die assembly thus does not exert any lateral force on the wire which might have an adverse aifect on the wire drawing operation, as for example, the wire causing uneven wear of the die. Further, the embodiment of the invention in FIGS. 6 and 7, as in the case of the embodiment of the invention in FIGS. 4 and 5, is useful where it is desired to provide a greater moment arm between the initial point of contact of the wire 212 with the die 224 and a swivel plane 238 of the die, than can be attained with the embodiment of the invention in FIGS. 2 and 3. In utilizing the embodiment of the invention in FIGS. 6 and 7, however, before the wire drawing machine 11 is restarted after having been stopped for any reason, care must be taken to insure that the die holders 226 have not become un seated from the slides 233 because of Wire backlash when the machine stopped.

While several embodiments of the invention have been disclosed, many other modifications will be apparent and it is intended that the invention be interpreted as including all modifications which fall within the true spirit and scope of the invention.

What is claimed is:

1. In apparatus for drawing wire and including spaced members between which the wire travels so as to form an advancing continuous length of the wire between the members, the improvement which comprises:

a wire drawing die mounted between said spaced members for universal movement such that the initial point of contact of the advancing wire with said die, as measured in the direction of advancement of the wire, is beyond a plane defined by transverse swivel axes of said die, said die being movable universally in response to lateral forces exerted on said die by the wire as the advancing continuous length of wire passes through said die.

2. Apparatus for drawing wire, which comprises:

spaced members between Which the wire travels so as to form an advancing continuous 'length of the wire between said members;

support means mounted between said spaced members adjacent the advancing continuous length of the wire for slidable movement laterally with respect to the advancing continuous length of the wire, said support means including a spherically shaped seat;

a wire drawing die; and

means for mounting said wire drawing die in the spherically shaped seat of said support means for universal movement, said die being movable universally in response to lateral forces exerted on said die by the wire as the advancing continuous length of the wire passes through said die, and the construction of said mounting means and said die being such that the initial point of contact of the advancing wire with said die, as measured in the direction of advancement of the wire, is beyond a plane defined by transverse swivel axes of said die.

3. Apparatus for drawing wire, as recited in claim 2, in which said mounting means includes an elongated substantially tubular member through which the advancing continuous length of the wire passes, said tubular mernf her being mounted adjacent a wire entrance end thereof for universal movement in the spherically shaped seat of said support means, and said wire drawing die being mounted on said tubular member adjacent a wire exit end thereof in spaced relationship withrespect to the spherically shaped seat of said support means.

4. Apparatus for drawing wire, as recited in claim 3,

passage therethrough from the interior to the exterior die.

thereof adjacent the wire entrance to said wire drawing References Cited UNITED STATES PATENTS Rapp 72467 Todt 72467 Walker 72467 See 72468 See 72.-467 Coan 72468 CHARLES w. LANHAM, Primary Examiner. in which said tubular member has at least one flushing 15 E. M. COMBS, Assistant Examiner.