US3646798A

US3646798A - Wire drawing apparatus and method

Info

Publication number: US3646798A
Application number: US9669A
Authority: US
Inventors: Richard A Alcock
Original assignee: FASTENER ENG Inc
Current assignee: FASTENER ENG Inc; FASTENER ENGINEERS Inc
Priority date: 1970-02-09
Filing date: 1970-02-09
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

A drum-type wire drawing apparatus and method wherein an intermediate coil of wire is wrapped in a single layer on a drawing drum assembly having inlet and outlet portions, the inlet portion is drivingly rotated with a sufficiently high torque to pull the wire through the die and wrap the drawn wire on the inlet portion, and the coil of wire is forced axially along the inlet portion onto the outlet portion where it is unwrapped from the drum assembly, and the wraps of wire on the outlet portion of the drum assembly are driven in the same direction and relative to wraps of wire on the inlet portion of the drum assembly to maintain the coil of wire tightly wrapped around the drum assembly.

Description

United States Patent Alcock Mar. 7, 1972 [54] WIRE DRAWING APPARATUS AND 3,099,412 7/1963 Mystrom ..242/47.0l

METHOD FOREIGN PATENTS OR APPLICATIONS hard k [72] Invent A l,067,760 10/1959 Germany ..72/289 [73] Assignee: Fastener Engineeis, Ine, Rockford, Ill.

Primary Examiner-Richard J. l-lerbst [22] Flled' 1970 Assistant Examiner-Michael J. Keenan [21] App]. N0.: 9,669 Attorney--McCanna,Morsbach,Pillote& Muir s21 u.s.c1 ..72/289, 72/288 [571 ABSTRACT [51] '1- B219 1/02 A drum-type wire drawing apparatus and method wherein an [58] Fleld of Search ..72/287, 288, 289; 242/25,47.0l, intermediate coil f wire is wrapped i a Single layer on a 242/1161 203 drawing drum assembly having inlet and outlet portions, the inlet portion is drivingly rotated with a sufficiently high torque [56] References to pull the wire through the die and wrap the drawn wire on UNITED STATES PATENTS the inlet portion, and the coil of wire is forced axially along the Inlet portion onto the outlet portion where 1t 1s unwrapped 3,402,588 9/1968 Guthrie ..72/289 from the drum assembly, and the wraps of wire on the outlet 1,973,596 9/ 1934 Y0usey...- -.72/ portion of the drum assembly are driven in the same direction 3,058,631 10/1962 ClaIkSOn-- 242/47139 and relative to wraps of wire on the inlet portion of the drum 3,402,589 9/ 1958 Lathom "72/289 assembly to maintain the coil of wire tightly wrapped around 2,669,347 2/1954 Mcllvried ..72/2s9 the drum assemb1y 3,280,611 10/1966 Lathom et al... .....72/289 2,237,371 4/1941 Simons ..72/289 19 Claims, 6 Drawing Figures 45 O 9/ 25 I I, I I/ I I 9 I II I e \l I 25 E v I l l x 81 ,1 \X a s I y/ 7/ 88 c 1 58 L IO 12 a 53 t e I -s K 73 55 5-4 we a f 77977737777 24 PAIENTEDMAR 7 I972 SHEET 2 [IF 3 1%; J. 41mg,

WIRE DRAWING APPARATUS AND METHOD BACKGROUND OF THE INVENTION The force required to pull a wire through a drawing die, commonly referred to as the draw box pull," varies as a function of wire size and wire hardness or tensile strength. In a drum-type wire drawing apparatus it is necessary to maintain the coil of wire wrapped sufficiently tightly around the drum to provide the requisite tractive force between the drum and the coil of wire to pull the wire through the drawing die. With increases in wire size and wire hardness or tensile strength, the problem of maintaining adequate tractive force between the drum and coil is increased not only due to the increase in draw box pull, but also due to the increased tendency of the wire to uncoil and loosen on the drum.

It has heretofore been the common practice to maintain sufficient tension on the wire as it leaves the drum to prevent loosening of the coil on the drum. However, maintaining the exiting tension on the wire sufficiently high to enable handling of large size and/or high tensile strength wire presents further problems. Thus, when the wire from the drawing apparatus passes to a subsequent wire processing machine, it has been found that the high exiting tension which had to be maintained on the wire often exceeded the capacity of the feed mechanism on the subsequent processing machine and resulted in improper feeding of the wire.

In order to minimize or even eliminate the necessity of maintaining high exiting tension on the wire as it leaves the drum, it has heretofore been proposed, as disclosed in the U.S. Patent to Guthrie U.S. Pat. No. 3,402,588, to utilize a plurality of clamps mounted on the drum for rotation therewith and which are sequentially operated to clamp an outlet wrap of wire to the drum during a portion of each revolution and to disengage the wire as the clamps rotate through a selected sector of each revolution to allow unwrapping of the wire at the outlet end of the coil from the drum. Such apparatus has operated satisfactorily for drawing large size wire as well as wire of high tensile strength. However, a number of clamps must be provided on the drum and sequentially operated once during each revolution of the drum between clamp and release position. The necessity of operating the clamps between clamp and release positions during each revolution limits the speed at which the drum can be rotated and hence the speed at which wire can be drawn. Moreover, this clamp mechanism is relatively complex in construction and operation and contains a number of parts which are subject to wear.

It is an object of the present invention to overcome the dis advantages of the prior art by providing a method and apparatus for drawing wire wherein the coil of wire is maintained tightly wrapped around the drum during operation of the drawing apparatus without requiring a high exiting tension on the wire leaving the drum or sequentially operated clamps on the drum.

Accordingly, the present invention provides a method for drawing wire in which an intermediate coil of wire is wrapped around a wire drawing drum assembly and the outlet portion of the coil is driven in a direction to angularly advance the same relative to inlet portion of thecoil in a manner to effect tightening of the coil of wire on the drum assembly sufficient to provide the requisite traction between the drum assembly and coil.

The present invention also provides a drum-type wire drawing apparatus having an auxiliary wire drawing drum coaxial with a main drum and arranged to receive the wraps of wire as they are moved axially off the main drum, and wherein the main drum is drivingly rotated to pull the wire through the draw die and the wraps of wire on the auxiliary drum are driven to angularly advance the same relative to those on the main drum and tighten the coil of wire on the wire drawing drum.

In a drum-type wire drawing apparatus, the tension in the several wraps of wire which make up the coil on the drum assembly decreases from a value equal to the draw box pull at the inlet end of the coil to a low or even zero tension at the outlet end. The traction between each of the wraps of the coil and the drum assembly correspondingly decreases with decreasing tension in the wraps of wire in a direction from the inlet to the outlet end of the coil. Accordingly, the present invention also advantageously includes a drive for the main and auxiliary drums which isso arranged as to limit the torque applied to the auxiliary drum to a value substantially less than that applied to the main drum and such as to minimize slippage of the auxiliary drum relative to the wraps of wire thereon when the coil is tightened on the drum assembly sufficient to provide the necessary traction to overcome the draw box pull.

These, together with other objects and advantages of this invention will be more readily appreciated as the invention becomes better understood by reference to the following detailed description when taken in connection with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a wire drawing apparatus embodying the present invention;

FIG. 2 is a partial plan view of the wire drawing apparatus 'of FIG. 1;

FIG. 3 is a vertical sectional view through the wire drawing drum, taken on the plane 3-3 of FIG. 1;

FIG. 4 is a schematic diagram illustrating the electrical and fluid controls for the wire drawing apparatus;

FIG. 5 is a fragmentary sectional view through the wire drawing drum taken on the plane 55 of FIG. I; and

FIG. 6 is a fragmentary side elevational view illustrating a modified form of the wire drawing apparatus.

The drum-type wire drawing apparatus and method of the present invention is generally useful for drawing wire and is particularly adapted for drawing wire which, by reason of large size and/or tensile strength tends to loosen and slip on a conventional wire drawing drum. The wire drawing apparatus and method may, moreover, be utilized to feed the drawn wire directly to a wire processing machine, or may be utilized to recoil the drawn wire for subsequent processing.

In accordance with the present invention, a coil including a number of wraps of wire in a single layer is formed around a drum assembly having coaxial inlet and outlet portions. The inlet portion of the drum assembly is drivingly rotated in one direction with a torque sufficiently high to pull the wire through the drawing die and cause the drawn wire to wrap on the inlet portion of the drum assembly. The coil of wire is forced axially along the inlet portion of the drum assembly and onto the outlet portion and wire is removed from the outlet portion of the drum assembly as it wraps on the inlet portion of the drum assembly. A portion of the coil at its outlet end is maintained in frictional contact with the outlet portion of the drum assembly and the wraps of wire on the outlet portion of the drum assembly are rotated in the same direction as the inlet portion of the drum assembly and relative thereto to angularly advance the wraps of wire on the outlet portion of the drum assembly relative to the wraps of wire on the inlet portion of the drum assembly and thereby tighten the coil on the drum assembly. The tension in wraps of wire which make up the intermediate coil on the drum assembly decreases from a value equal to the draw box pull at the inlet end of the coil to a low or even zero tension at the outlet end of the coil. The traction between each of the wraps of the coil and the drum assembly correspondingly decreases with decreasing tension in the wraps, in a direction from the inlet to the outlet end of the coil. Accordingly, the driving torque applied to drive the wraps on the auxiliary drum is advantageously limited to a value substantially lower than that applied to the main drum, yet sufficient to tighten the coil around the drum assembly and provide the necessary traction to overcome the draw box pull.

The wire drawing apparatus in general includes a wire drawing die 11 and a wire drawing drum assembly 12 for receiving an intermediate coil of wire composed of a plurality of wraps of wire. and having an inlet end where the wire from the die means begins to wrap on the drum means and an outlet end where the wire is removed or unwraps from the drum. The wire drawing drum assembly includes a main drawing drum 13 mounted for rotation about its axis and an auxiliary drawing drum 14 coaxial with the main drum and mounted for rotation relative thereto. The main drum has an annular main wire engaging surface l3a, the axial width of which is sufficient to receive a number of wraps of wire which form a portion designated C1 of the intermediate coil, and the auxiliary wire drawing drum has an annular wire engaging surface designated 14a that merges with the outlet end of the main wire-engaging surface 13a and forms a continuation thereof. A number of wraps of wire which form the outlet portion designated C2 in FIG. 3 of the intermediate coil are disposed around the auxiliary drum. A flange 13b is provided adjacent the inlet end of the wire drawing drum assembly for forcing the wraps of the intermediate coil axially along the main wireengaging surface 13a and onto the auxiliary wire-engaging sur face 14a as the wire wraps onto the wire drawing drum as sembly. A main drive mechanism 15 is provided for drivingly rotating the main drum 13 in one direction about its axis to draw the wire W through the draw die 11 and wrap the same on the drum assembly adjacent the inlet end thereof, and auxiliary drive mechanism 16 is provided for driving the portion C2 of the intermediate coil in the same direction as the main drum and C1 to thereby tend to tighten the intermediate coil about the drum assembly. In the preferred embodiment illustrated, the auxiliary drive 16 is arranged to drive the auxiliary drum and to limit the torque applied to the auxiliary drum to a value substantially lower than that applied to the main drum and such as to minimize slippage of the auxiliary drum relative to the wraps of wire thereon, when the coil is tightened on the drum assembly sufficient to overcome the draw box pull. This is advantageously achieved by an auxiliary drive motor 160 of a type which can be driven to a stall condition and wherein the torque output under stall conditions can be adjusted to provide the desired torque for driving the auxiliary drum. A wrap of wire at the outlet end of the coil is held in frictional contact with the auxiliary drum so that rotation of the auxiliary drum is effective to urge the wraps of wire on the auxiliary drum in a direction to angularly advance the same relative to the wraps on the main drum. While the outlet wrap of wire can be held in frictional contact with the auxiliary drum by maintaining tension on the wire as it leaves the drum, the exiting tension can be reduced or even eliminated by radially pressing an outlet wrap of wire against an auxiliary drum by a roller assembly 18.

In the embodiments illustrated, the wire drawing drum assembly 12 is mounted for rotation in a vertical plane, it being understood that the wire drawing drum means could be otherwise mounted for rotation for example in a horizontal plane if desired. As best shown in FIG. 3, the drum has a hub 21 which is nonrotatably connected as by a key 22 to a shaft 23. The shaft 23 is rotatably supported on a base 24 as by stanchions 25 attached to the base and bearing blocks 26. The main drum drive means 15 can be of any suitable type capable of driving the main drum with sufficient torque to overcome the draw box pull on the wire and includes ameans for varying the speed at which the main drum is rotated. In the form shown, the main drum drive apparatus includes a drive motor 28 and a variable speed mechanism 29 having its output shaft 290 connected as through a belt or chain drive 31 to the drum drive shaft. The variable speed mechanism 29 may, for example, be of variable speed mechanical drive; a fixed speed mechanical drive with a selectively controlled variable slip clutch; or a variable speed hydraulic drive such as an hydrostatic transmission. Alternatively, if a variable speed drive is not required for the purpose of synchronizing the wire drawing machine with a subsequent wire processing'machine, then the drum drive can be controlled by a control relay which is operable to start and stop the drive motor.

The wire W from the drawing die wraps on the main drum 13 as the latter rotates and the drum flange 13b is inclined as shown in FIG. 3 so that the wire, as it wraps on the main drum, forces the previous wraps of wire which form the intermediate coil axially along the main drum and onto the auxiliary drum. The circumferential slippage and axial movement of the wire along the drum tends to cause wear of the wire-engaging surface, particularly in the region adjacent the inlet end of the drum. For this purpose and to also enable changing of the axial width of the wire-engaging surface on the drum, if desired, the main wire drawing drum is advantageously formed with a demountable rim (FIG. 3) which is mounted on the main drum as by fasteners 13d, in a manner more fully disclosed in US. Pat. No. 3,280,61 l.

The auxiliary drawing drum 14 is supported for rotation relative to the main drive drum 13 and in the form shown in FIG. 3, the auxiliary drum has a hub portion 34 which is rotatably supported as by roller bearings 35 and thrust washers 36 and 37 on the outer end portion 21a of the main drum hub 21. A means such as split collar 38 is provided for retaining the auxiliary drum on the main drum.

The wire-engaging surface 13a of the main drum is preferably generally cylindrical and the wire-engaging surface 14a of the auxiliary drum is also preferably cylindrical and of substantially the same diameter so that the wire-engaging surface 144 of the auxiliary drum effectively forms a continuation of the surface 13a to allow the wraps of wire to move axially off the main drum and onto the auxiliary drum. The auxiliary drum drive means 16 is arranged to rotate the auxiliary drum relative to the main drum in a direction to tighten the intermediate coil of wire on the main drum. As will be understood, rotation of the auxiliary drum relative to the main drum can be effected by a drive which is independent of the drive for the main drum and which is capable of rotating the auxiliary drum relative to the main drum to effect tightening of the intermediate coil of wire. It is preferred, however, that the drive means for the auxiliary drum be arranged to drivingly interconnect the main and auxiliary drums so that the auxiliary drive means operate at a low speed correlative with the difference in speeds between the main and auxiliary drums, in order to drive the auxiliary drum relative to the main drum. In the form shown in FIGS. 1-5, the auxiliary drum drive apparatus includes the aforementioned auxiliary drive motor and a speed reducer mechanism 16b mounted on one of the drums at a point radially spaced from the axis of rotation of the drums. The motor 16a is herein shown mounted on the auxiliary drum 14 as by fasteners 41 and has a drive pinion 42 that meshes with a gear 43 secured as by fasteners 44 to the main drum 13. The gear 43 is disposed concentric with the axis of the drums and, when the drive pinion 42 is rotated, the auxiliary drum is rotated relative to the main drum at a speed proportional to the speed of rotation of the pinion 42 about its axis. Thus, when the pinion 42 is stationary about its own axis, the auxiliary drum will rotate at the same speed as the main drum, and when the pinion 42 is rotated in a counterclockwise direction as viewed in FIG. 1, it will rotate the auxiliary drum in a counterclockwise direction relative to the main drum. While it is necessary to maintain the intermediate coil wrapped sufficiently tightly around the drum to provide the requisite traction for drawing the wire through the die means 11, it is desirable to avoid excessive tightening of the coil around the drum since this inhibits axial movement of the wraps of wire which form the intennediate coil along the drum. The auxiliary drum drive means is accordingly arranged to limit the torque applied to rotate the auxiliary drum to prevent excessive tightening of the coil on the drum and to also limit slippage of the auxiliary drum relative to the wraps of wire thereon. While limiting of the torque for the auxiliary drum drive can be effected by a torque limiting clutch, it is advantageously effected by utilizing an electric or fluid motor 16a of a type which can be driven to stall conditions and the torque output of which can be selectively adjusted. In the preferred form, the motor 16a is of the positive displacement fluid type and may, for example, be a gear, vane, or pistontype fluid motor and a means, described hereinafter, is provided for regulating the pressure applied to the fluid motor to thereby regulate the torque output. The piston-type fluid motor is presently preferred since such motors generally have a high volumetric efficiency and consequently relatively low leakage, even at stall conditions.

In order for the rotation of the auxiliary drum to be effective to tighten the coil, it is necessary to maintain at least the outlet wrap of the intermediate coil in frictional contact with the periphery of the drum. The force required to maintain the outlet wrap of the intermediate coil against the wire-engaging surface on the auxiliary drum can be provided by maintaining a tension on the wire as it leaves the drum. However, in the preferred embodiment, a roller assembly 18 is provided to radially press the outlet wrap of wire against the auxiliary drum so as to minimize and even avoid the necessity of maintaining exiting tension on the wire. As best shown in FIG. I, the pressure applying roller assembly 18 is located at the portion of the drum opposite the side from which the wire exits from the drum. Thus, in the form shown wherein the wire exits adjacent the bottom of the drum, the pressure applying roller assembly 18 is located-angularly in advance of the bottom of the drum. The roller assembly shown in FIGS. 1-5 comprises a pair of rollers 51 mounted at opposite ends of a link 53 which is pivotally supported intermediate its ends on the outer end of an arm 54. The arm 54 is nonrotatably attached to a shaft 56 which is rotatably supported in brackets 57 on the base 24. A lever 58 is attached to the shaft and a means such as a fluid actuator 59 (HO. 4) is provided for yieldably urging the rollers into engagement with the wire to radially press the outlet wrap of wire against the auxiliary drum. As shown in FIG. 5, the rollers are formed with a concave periphery 51a to receive the outlet wrap of wire and center the rollers therewith. In order to minimize the circumferential drag which the rollers might impose on the outlet wrap of the wire, and which would tend to cause loosening of the outlet wrap, the rollers are preferably formed with a contour of a shape to provide substantially line contact with the outlet wrap. Thus, as shown, the arcuate periphery of the rollers 51 are formed with a radius of curvature greater than that of the wire being drawn.

The

pressure applying rollers

51, 52 described in connection with FIGS. 15 are idler rollers driven by engagement with the wire. However, it is contemplated that the pressure applying rollers could be driven to not only overcome any circumferential drag which the rollers might otherwise impose on the wire, but to also aid in driving the outlet wraps of wire and the auxiliary drum in the direction to tighten the coil on the drum assembly. In the embodiment shown in FIG. 6, like numerals are used to designate parts corresponding to those described in the embodiment of FIGS. 1-5. In FIG. 6, a pressure applying roller SI is mounted on arm 54 carried by the shaft 55. The roller 51 is yieldably urged into engagement with the end wrap of wire on the auxiliary drum by the aforedescribed actuator 59. The roller 51, however, is driven in a direction as shown by the arrow in FIG. 6, and at a peripheral speed sufficiently higher than that of the main drive to aid in driving the outlet wrap of wire and the auxiliary drum in a direction to tighten the coil on the drum assembly. This is advantageously achieved by a drive motor 131 mounted on arm 54 and drivingly connected to roller 51. The motor 131 may be an electrical or fluid type which can be driven to stall conditions and, as shown, is of the fluid type such as a positive displacement gear, vane or piston air motorv Fluid such as air is supplied to the motor 131 from a source 132 under the control of a pressure regulator 133 and valve 134. The pressure regulator is of the adjustable type which can be adjusted to regulate the pressure supplied to the motor 131 and hence adjust the torque output of the motor. When the drive motor 16a is used to drive the auxiliary drum, the peripheral speed of the pressure applying roller 51 can be equalized with the peripheral speed of the wire on the auxiliary drum by regulating the pressure applied to the motor 131 such that the torque applied to the roller is grater than that required to drive the roller, but insufficient to cause the roller 13! to slip on the wrap of wire which it engages. In this manner, the speed of the wire on the drum will control the speed at which the roller 131 is driven. However, it is contemplated that, in some applications, the drum drive motor 16:: may be placed in neutral condition under control of valve 91 and that the motor R31 for the roller 51' used to drive the outlet wrap of wire and the auxiliary drum. This can be achieved by adjusting the pressure regulator 133 to a value such that the output torque of motor 13] applied to roller 51' is sufficient to circumferentially drive the outlet wrap of wire on the auxiliary drum and by adjusting regulator 83 to a value such that the force applied by actuator 79 to pressurize the roller 51' against the outlet wrap of wire on the drum is sufficient to prevent excessive slippage between the roller 51' and the outlet wrap and between the outlet wrap and the auxiliary drum. Under these conditions, the roller 51 can function to drive the auxiliary drum with the wrap of wire thereon.

As previously described, the wire can be removed axially from the end of the drum, for example onto a coil frame, or can pass laterally off the drum to a subsequent wire processing machine or rewind apparatus. A means is advantageously provided for sensing any difference in the speed at which wire is drawn by the drawing apparatus and the speed at which wire is consumed by the subsequent processing machine and for automatically controlling the speed of the drawing apparatus to compensate for the difference. In the embodiment shown, this means includes a compensator roll 61 mounted on a swingable arm 62. The roll 61 is arranged to engage the slack loop L of wire after it leaves the wire drawing apparatus and the roll 61 is yieldably urged in a direction to increase the size of the slack loop as by a fluid actuator 63. As diagrammatically shown in FIG. 4, a means 65 is provided for sensing the position of the compensator arm 62 and for operating the speed control mechanism of the main drive apparatus. For example,

if the variable speed drive apparatus includes a variable slip clutch, the sensing apparatus can be utilized to control the clutch to control the speed of the drum drive; if the variable speed drive apparatus is of the hydrostatic transmission type,

the sensing apparatus 65 can be utilizedto adjust the hydrostatic transmission to control its output speed; and if the variable speed drive 29 is of the mechanical type wherein the speed is adjusted manually, then the speed of the drum drive can be adjusted so as to be slightly greater than that at which the wire is consumed by the subsequent processing machine and the sensing apparatus 65 can operate a control mechanism to start and stop the drum drive motor 28 as may be required to equalize the average rate at which the wire is drawn and the rate at which his fed to a subsequent wire processing machine.

The wire wrapped around the drum tends to uncoil quite violently when the tension on the incoming wire is suddenly released, as occurs when the end of the wire passes through the die means. In addition, if the drum is stopped, or if the rate of drawing of the wire exceeds the rate at which the wire is processed by the subsequent machine sufficient to cause a backup of wire, the intermediate coil can become loosened on the drum and the individual wraps displaced. In order to prevent rapid uncoiling or displacement of the wrap of the in-.

terrnediate coil on the drum under the above conditions, a selectively operable clamp shoe 71 is provided for clamping the wires to the periphery of the drum. As shown, the clamp shoe 71 is supported for movement into and out of engagement with the wire on the drum and is mounted on an arm 72 attached to a shaft 73 which is rotatably supported on the base. A lever 74 (FIG. 2) is connected to the shaft 73 and a clamp shoe actuator 75 is provided for operating the clamp shoe 7]. During normal operation, the clamp shoe 71 is positioned adjacent to, but out of clamping engagement with, the wraps of wire on the drum and a means, described hereinafter is provided for automatically moving the clamp shoe into clamp position in the event the compensator means senses an excessive slack in the loop L of wire exiting from the drum.

Reference is now made more specifically to the diagrammatic electrical and fluid control circuit shown in FIG. 43. Fluid such as air under pressure is supplied to the auxiliary drum drive motor from an air supply 81 to a filter 82, regulator 83 and lubricator 84 to a line 85. The line 85 is connected through a rotary gland 86 (FIG. 2) to a passage 87 (FIG. 3) in the main. drum drive shaft 23, the outlet end of which is connected through a rotary gland 88 to a line 89 leading to a control valve 91. The control valve 91, as shown in FIG. 1, is conveniently mounted on the auxiliary drum for rotation therewith and has an inlet port 91a, an exhaust port 91b, and controlled outlet ports 91c and 91d. The valve is preferably of the manually operable three-position flow reversing type as diagrammatically shown in FIG. 4 and has a midposition in which the inlet port is blocked and the controlled outlet ports 91c and 91d are intercommunicated with each other and with the exhaust port 9112 so as to place the auxiliary drum drive motor in a neutral position. Valve 91 is selectively movable to a forward and reverse position to selectively drive the auxiliary drive drum either forward in the same direction as the main drive drum, or in reverse. The valve is preferably of a type which is spring loaded out of its reverse position to the neutral position and which is arranged to be held as by a detent in its forward position. The regulator 81 is selectively adjustable to regulate the pressure applied to the fluid motor 160, and to thereby regulate the torque applied by the fluid motor to the auxiliary drum. A pressure gauge 92 may be provided to give visual indication of the regulated pressure applied to the auxiliary drive motor to facilitate adjustment of the output torque.

Fluid pressure from the air supply 81 is also applied through a line 95 and regulator 96 to the actuator 63 for the compensator mechanism. The regulator 96 is also preferably of the type which is adjustable to adjust the pressure applied to the compensator and a gauge 97 is provided to indicate the regulated pressure applied to the compensator.

Fluid pressure is further supplied through a line 101 and regulator 102 and control valve 103 to the clamp roller actuator 59. The clamp roller actuator is of the double-acting type and valve 103 is preferably a manually operable two-position valve having an inlet port 103a, an exhaust port 10311 and controlled

outlet ports

1030 and 103d which are connected through lines 104 to the actuator 59. The valve is normally positioned as shown in FIG. 4 to supply fluid pressure to the actuator in a direction to urge the clamp rollers into wire-engaging position and the valve 103 can be manually moved to its other position to shift the clamp rollers away from the drum during start of a wire drawing operation.

The clamp shoe actuator 75 is also of the double-acting type and is controlled by a valve 108 having a supply inlet 108a, and exhaust outlet 108k and controlled outlets 108c and 108d.

'Fluid under pressure is supplied to the inlet 1080 through a line 111 conveniently connected to the outlet of the regulator 83, or to a separate regulator if desired. The controlled outlets 1080 and 108d are connected to the actuator 75 and valve 108 is preferably the three-position flow reversing type which is spring urged to its neutral position in which the controlled outlet ports are connected to each other and to the exhaust line to allow the actuator 75 to float while the inlet port 108a is blocked. Electroresponsive actuators 112 and 113 are provided for moving the valve 108 respectively to its clamp and release position. As previously described, the'clamp shoe 71 is provided for holding the clamps of wire on the drum when it is stopped or when the wire becomes slack and is preferably automatically operated to its clamp position as by a switch 115 operated from the compensator arm 62. As schematically illustrated in FIG. 4, power is supplied to the valve actuator 112 from an electric supply source 121 through

conductors

122 and 123 and normally open switch 115. In the event the compensator lever 62 swings to the right as viewed in FIG. 4, incident to excessive slack in the loop L of wire exiting from the drawing drum, the switch 115 is operated to complete a circuit through the actuator 112 and move the valve 108 to its forward position to thereby operate actuator 75 and press the clamp shoe 71 against the wire on the drum to hold the same in position. Valve 108 is spring returned to its neutral position and can be selectively operated to its reverse position under the control of a manually operable switch 124 which is connected through the conductors 125 and 126 to the other electroresponsive actuator 113.

OPERATION In order to start a drawing operation it is necessary to first draw a length of wire at least sufficient to form the intermediate coil. The end of the wire which has been pointed, either by grinding down the end to allow insertion through the die means or which has a reduced diameter leader welded thereto, is first inserted through the die means. The end of the wire is then secured to the drum assembly by a conventional wire gripper and chain anchor arrangement. During the startup operation, the auxiliary drive motor control valve 91 is positioned in its neutral position shown in FIG. 4 and the auxiliary drawing drum 14 is preferably nonrotatably connected to the main drum. For this purpose a removable locking pin is provided and arranged to be inserted through aligned

openings

136 and 137 in the auxiliary and main drums respectively as shown in FIG. 3. The main drive motor is then operated to rotate the drum through a number of revolutions sufficient to form the intermediate coil comprising a number of wraps C I on the main drum and the further wraps C2 on the auxiliary drum and rotation of the drum is continued to draw an additional length of wire sufficient to pass over the compensator roller 61. The brake shoe can be held in its release position during startup, by operation of switch 124. The roller clamp 51 is then moved to its operative position in engagement with a wrap of wire on the auxiliary drum by operation of the valve 103 to its forward position. The additional length of wire referred to above can then be separated from the drum and passed over the compensator roller 61.

The drawing apparatus of FIGS. 1-5 can thereafter be put in automatic operation by removing the locking pin and by moving valve 91 to its forward position so as to drive the auxiliary drive motor in its forward direction and begin rotation of the auxiliary drum in the direction of the main drawing drum so as to tend to angularly advance the portion C2 of the intermediate coil relative to the portion C1 and thereby tighten the coil on the drawing drum. The main drive motor operates to rotate the main drawing drum and pull the wire through the die and the drawn wire wraps on the main drum at its inlet end. As the wire wraps on the main drum, it is forced by the flange 13b axially along the main drum and onto the auxiliary drum where the wire unwraps from the drum assembly. The main drive apparatus applies sufficicnt torque to the main drum to pull the wire through the die means and the auxiliary drive apparatus applies sufficient torque to the auxiliary drum to effect tightening of the coil without excessive slippage of the auxiliary drum relative to the wraps of wire thereon. The torque applied by the auxiliary drive apparatus is selectively adjusted by the adjustment of regulator 81 to apply a pressure to the auxiliary drive motor such that, when the auxiliary drive motor is stalled, it applies at least sufficient torque to the auxiliary drive drum to tighten the coil on the drum assembly. In practice, the torque which must be applied to the auxiliary drum is small as compared to that which is applied to the main drum. For example, in drawing carbon steel rod identified by AISI number C1039 from 41/64 to 0.610 inch diameter at approximately l0 feet per minute using a drawing drum having a 3 foot diameter with 10 wraps of wire on the main drum and about 3% wraps of wire on the auxiliary drum, about 100,000 inch pounds of torque were required to drive the main drum while about 400 inch pounds of torque were found adequate to drive the auxiliary drum without causing excessive slip of the auxiliary drum relative to the wraps of wire thereon and while yet maintaining the coil sufficiently tight on the main drum to prevent slipping of the main drum. The auxiliary drive motor was a piston-type fluid motor having a three-stage speed reduction and capable of producing about 1,300 inch pounds of torque under stall conditions at 90 p.s.i. and engaged at 2 foot diameter ring gear on the maindrum. Only slight slippage between the auxiliary drive drum and the wraps of wire thereon occurred when the auxiliary drive motor was operated at about 50 p.s.i., producing about 500 inch pounds of torque output (about 400 inch pounds on the auxiliary drum), and substantially no slip occurred between the main drum and the coil of wire. When the air pressure to the auxiliary drive motor was increased to 80 p.s.i., somewhat greater slipping of the auxiliary drive drum relative to the coil of wire was observed.

The pressure applied to the roller clamp is adjusted to a value greater than that necessary to overcome the tendency of the wire to radially expand and separate from the drum so that the roller clamp is effective to hold the wire in frictional contact with the drum. In the form shown in FIGS. 1-5, the roller clamp only operates to circumferentially advance the outlet wraps of wire. In the embodiment of FIG. 6, the roller clamp 51' is driven and not only radially presses the outlet wrap of wire against the drum, but also operates to drive the outlet wrap of wire circumferentially in a direction to tend to advance the outlet wraps of wire relative to the wraps on the inlet section of the drum. In practice it has been found that outlet wraps of wire and the auxiliary drive drum can be driven relative to the main drum to maintain a coil of wire wrapped sufficiently tightly around the drum so that it is unnecessary to maintain any tension on the wire leaving the drum, and that the wire can even be positively forced from the drum and fed to the subsequent feed apparatus. However, in some applications, a slight or moderate tension on the wire leaving the drum may be useful or desirable, and it is contemplated that the apparatus can be used to advantage in such applications.

The number of wraps of wire which must be provided on the intermediate coil varies with the wire size and/or hardness or tensile strength. In any event, in order for the apparatus to operate it is necessary to provide intermediate coil having at least some wraps on the main drum and at least one and preferably several wraps on the auxiliary drum. If it is desired to increase or decrease the width of the wire drawing surfaces on the main drum, to accommodate coils of greater or less axially widths, it can be achieved by utilizing difi'erent rims 130 or by utilizing a spacer as disclosed in the aforementioned patent.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a wire drawing apparatus including wire drawing die means, wire drawing drum means for receiving an intermediate coil of wire composed of a plurality of wraps of wire and having an inlet end where the wire from the die means begins to wrap on the drum means and an outlet end; the improvement wherein said wire drawing drum means comprises a main drawing drum mounted for rotation about its axis and an auxiliary drawing drum coaxial with the main drum and mounted for rotation relative thereto, said main drum including an annular main wire engaging surface having an axial width sufficient to receive a number of wraps of wire which is less than said plurality of wraps that make up said intermediate coil, said auxiliary drawing drum including an annular auxiliary wire-engaging surface merging with the outlet end-of the main wire-engaging surface and forming a continuation thereof, means adjacent the inlet end of the wire drawing drum means for forcing the wraps of said intermediate coil axially along the main wire-engaging surface and onto said auxiliary wire-engaging surface as the wire wraps onto the wire drawing drum means, main drive means for drivingly rotating said main drum in one direction, and auxiliary drive means for rotating said auxiliary drum and the wraps of wire thereon in said one direction and relative to the main drum to tighten the intermediate coil of wire on the drawing drum means.

2. A wire drawing apparatus according to claim I wherein said auxiliary drive means for rotating said auxiliary drum includes means for limiting the torque applied to the auxiliary drum to a value substantially lower than force required to pull the wire through said drawing die means.

3. A wire drawing apparatus according to claim 1 wherein said main drive means for drivingly rotating said main drum includes a main drive motor drivingly connected to the main drum and operative to apply torque to the main drum suffrciently high to pull wire through the die means, said auxiliary drive means for drivingly rotating the auxiliary drum including an auxiliary drive motor means drivingly connected to the auxiliary drum to rotate the latter and operative to limit the torque applied to the auxiliary drum to a value substantially lower than that applied-to the main drum.

4. A wire drawing apparatus according to claim 3 including means for selectively regulating the torque applied by said auxiliary drive motor to said drum.

5. A wire drawing apparatus according to claim 3 wherein said auxiliary drive motor is a positive displacement-type fluid motor and means is provided for adjustably regulating the pressure applied to the fluid motor to regulate the torque applied to the auxiliary drum.

6. A wire drawing apparatus according to claim 1 wherein said means for drivingly rotating said auxiliary drum relative to said main drum includes a first gear means rotatable with one of said drums and coaxial therewith, a second gear means meshing with said first'gear means and rotatably mounted on the other of said drums, and means for drivingly rotating said second gear.

7. An apparatus according to claim 1 including means engageable with a wrap of wire on said auxiliary drum for radially pressing the same into contact with the auxiliary drum as the latter rotates.

8. An apparatus according to claim 7 wherein said last-mentioned means includes a roller disposed in rolling engagement with the outlet wrap of wire on the auxiliary drum, and means for pressing said roller toward the drum to press the outlet wrap of wire against the auxiliary wire-engaging surface.

9. An apparatus according to claim 8 including means for driving said roller in a direction to aid advancement of the wire with the auxiliary drum.

10. In a wire drawing apparatus including wire drawing die means, wire drawing drum means for receiving an intermediate coil of wire composed of a plurality of wraps of wire and having an inlet end where the wire from the die means begins to wrap on the drum means and an outlet end; the improvement wherein said wire drawing drum means comprises a main drawing drum mounted for rotation about its axis and an auxiliary drawing drum coaxial with the main drum and mounted for rotation relative thereto, said main drum including an annular main wire-engaging surface having an axial width sufficient to receive a number of wraps of wire which is less than said plurality of wraps that make up said intermediate coil, said auxiliary drawing drum including an annular auxiliary wire-engaging surface merging with the outlet end of the main wire-engaging surface and forming a continuation thereof, means adjacent the inlet end of the wire drawing drum means for forcing the wraps of said intermediate coil axially along the main wire-engaging surface and onto said auxiliary wire-engaging surface as the wire wraps onto the wire drawing drum means, means for drivingly rotating said main drum in one direction at a selected rotational speed with suffrcient-torque to pull the wire through the drawing die means, means including roller'means engaging a wrap of wire on the auxiliary drum for pressing the wrap of wire against the wireengaging surface on the auxiliary drum, and auxiliary drive means operable to drive one of said items comprising the roller mean and said auxiliary drum in said one direction at a rotational speed sufficiently higher than the rotational speed of said main drum to tighten the intermediate coil of wire on the drawing drum.

1]. A wire drawing apparatus according to claim 10 wherein said auxiliary drive'means includes means for limiting the torque applied to said one of said items to a value which is substantially less than the force required to pull the wire through the drawing die means.

12. In a wire drawing apparatus including wire drawing die means, wire drawing drum means for receiving an intermediate coil of wire composed of a plurality of wraps of wire and having an inlet end where the wire from the die means begins to wrap on the drum means and an outlet end; the improvement wherein said wire drawing drum means comprises a main drawing drum mounted for rotation about its axis and an auxiliary drawing drum coaxial with the main drum and mounted for rotation relative thereto, said main drum including an annular main wire-engaging surface having an axial width sufficient to receive a number of wraps of wire which is less than said plurality of wraps that make up said intermediate coil, said auxiliary drawing drum including an annular auxiliary wire-engaging surface merging with the outlet end of the main wire-engaging surface and forming a continuation thereof, means adjacent the inlet end of the wire drawing drum means for forcing the wraps of said intermediate coil axially along the main wire-engaging surface and onto said auxiliary wire-engaging surface as the wire wraps onto the wire drawing drum means, main drive means including a main drive motor operatively connected to said main drawing drum for drivingly rotating the main drum in one direction to pull wire through said drawing die means, and auxiliary drive means including an auxiliary drive motor operatively connected to said auxiliary wire drawing drum to rotate the auxiliary drum in said one direction about its axis and relative to the main drum to tighten the intermediate coil of wire on the drawing drum means.

13. A wire drawing apparatus according to .claim 12 wherein said auxiliary drive means includes for limiting the torque applied to said auxiliary wire drawing drum to a value substantially less than the force required to pull the wire through the die means.

14. A wire drawing apparatus according to claim 12 wherein said auxiliary drive motor is a positive displacementtype fluid motor, and said auxiliary drive means for regulating the pressure applied to the fluid motor to limit the torque applied to the auxiliary drawing drum.

15. A wire drawing apparatus according to claim 12 wherein said auxiliary drive motor is mounted on one of said drums and has a drive pinion rotatable about an axis parallel to and radially spaced from the axis of said drums, said auxilia- I I ry drive means including an annular gear on the other said drums concentric with the axis of said drums and meshing with said drive pinion.

16. A wire drawing apparatus according to claim 15 wherein said auxiliary drive motor is a positive displacementtype fluid motor, said auxiliary drive means including means for regulating the pressure applied to the fluid motor to limit the torque applied to the auxiliary drawing drum.

17. An improved method of drawing wire through a drawing die comprising, forming a coil including a number of wraps in a single layer on a drawing drum assembly having coaxial inlet and outlet portions of like outer diameter rotatable relative to each other and forming an axially continuous drive surface, drivingly rotating the inlet portion of the drum in one direction with a torque sufficiently high to pull the wire through the drawing die and cause the drawn wire to wrap on the inlet portion of the drum assembly, forcing the coil of wire axially along the inlet portion of the drum assembly and onto the outlet portion of the drum assembly and removing wire from the outlet portion of the drum assembly as the wire wraps on the inlet portion of the drum assembly, and drivingly rotating the outlet portion of the drum assembly in said one direction and relative to the inlet portion of the drum assembly to tighten the coil on the drum assembly.

18. The method of claim 17 including limiting the torque applied to drive the outlet portion of the drum assembly to a value which is substantially lower than that applied to the inlet portion of the drum assembly and sufficient to maintain the wire coil tightly wrapped around the drum assembly.

19. An improved method of drawing wire through a drawing die comprising forming a coil including; number of wr a in a single layer on a drawing drum assem ly having coax: inlet and outlet portions of like outer diameter rotatable relative to each other and forming an axially continuous drive surface, drivingly rotating the inlet portion of the drum in one direction with a torque sufficiently high to pull the wire through the drawing die and cause the drawn wire to wrap on the inlet portion of the drum assembly, forcing the coil of wire axially along the inlet portion of the drum assembly and onto the outlet portion and removing wire from the outlet portion as the wire wraps on the inlet portion of the drum assembly,

pressing a roller against an outlet wrap of wire on the outlet portion of the drum assembly, and drivingly rotating one of the items comprising the roller and the auxiliary drum as sembly with a torque sufficient to drive the outlet wrap of wire in said one direction and relative to the wraps of wire on the inlet portion of the drum assembly to tighten the coil on the drum assembly,

H050 UNITED STATES PATENT OFFICE 569 CERTIFICATE OF CORRECTION Patent No. 3,6 16 ,798 I Dated March 7, 1972 Inventor(5) Richard A. AlCOCk It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 10, line 67, "mean" should be means Column 11, line 30, after "includes" should be inserted means Column 11, line 44, after "other" should be inserted of Signed and sealed this 12th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

1. In a wire drawing apparatus including wire drawing die means, wire drawing drum means for receiving an intermediate coil of wire composed of a plurality of wraps of wire and having an inlet end where the wire from the die means begins to wrap on the drum means and an outlet end; the improvement wherein said wire drawing drum means comprises a main drawing drum mounted for rotation about its axis and an auxiliary drawing drum coaxial with the main drum and mounted for rotation relative thereto, said main drum including an annular main wire engaging surface having an axial width sufficient to receive a number of wraps of wire which is less than said plurality of wraps that make up said intermediate coil, said auxiliary drawing drum including an annular auxiliary wire-engaging surface merging with the outlet end of the main wire-engaging surface and forming a continuation thereof, means adjacent the inlet end of the wire drawing drum means for forcing the wraps of said intermediate coil axially along the main wire-engaging sUrface and onto said auxiliary wire-engaging surface as the wire wraps onto the wire drawing drum means, main drive means for drivingly rotating said main drum in one direction, and auxiliary drive means for rotating said auxiliary drum and the wraps of wire thereon in said one direction and relative to the main drum to tighten the intermediate coil of wire on the drawing drum means.

2. A wire drawing apparatus according to claim 1 wherein said auxiliary drive means for rotating said auxiliary drum includes means for limiting the torque applied to the auxiliary drum to a value substantially lower than force required to pull the wire through said drawing die means.

3. A wire drawing apparatus according to claim 1 wherein said main drive means for drivingly rotating said main drum includes a main drive motor drivingly connected to the main drum and operative to apply torque to the main drum sufficiently high to pull wire through the die means, said auxiliary drive means for drivingly rotating the auxiliary drum including an auxiliary drive motor means drivingly connected to the auxiliary drum to rotate the latter and operative to limit the torque applied to the auxiliary drum to a value substantially lower than that applied to the main drum.

6. A wire drawing apparatus according to claim 1 wherein said means for drivingly rotating said auxiliary drum relative to said main drum includes a first gear means rotatable with one of said drums and coaxial therewith, a second gear means meshing with said first gear means and rotatably mounted on the other of said drums, and means for drivingly rotating said second gear.

10. In a wire drawing apparatus including wire drawing die means, wire drawing drum means for receiving an intermediate coil of wire composed of a plurality of wraps of wire and having an inlet end where the wire from the die means begins to wrap on the drum means and an outlet end; the improvement wherein said wire drawing drum means comprises a main drawing drum mounted for rotation about its axis and an auxiliary drawing drum coaxial with the main drum and mounted for rotation relative thereto, said main drum including an annular main wire-engaging surface having an axial width sufficient to receive a number of wraps of wire which is less than said plurality of wraps that make up said intermediate coil, said auxiliary drawing drum including an annular auxiliary wire-engaging surface merging with the outlet end of the main wire-engaging surface and forming a continuation thereof, means adjacent the inlet end of the wire drawing drum means for forcing the wraps of said intermediate coil axially along the main wire-engaging surface and onto said auxiliary wire-engaging surface as the wire wraps onto the wire drawing drum means, means for drivingly rotating said main drum in one direction at a selected rotational speed with sufficient torque to pull the wire through the drawing die means, means inclUding roller means engaging a wrap of wire on the auxiliary drum for pressing the wrap of wire against the wire-engaging surface on the auxiliary drum, and auxiliary drive means operable to drive one of said items comprising the roller mean and said auxiliary drum in said one direction at a rotational speed sufficiently higher than the rotational speed of said main drum to tighten the intermediate coil of wire on the drawing drum.

11. A wire drawing apparatus according to claim 10 wherein said auxiliary drive means includes means for limiting the torque applied to said one of said items to a value which is substantially less than the force required to pull the wire through the drawing die means.

13. A wire drawing apparatus according to claim 12 wherein said auxiliary drive means includes for limiting the torque applied to said auxiliary wire drawing drum to a value substantially less than the force required to pull the wire through the die means.

14. A wire drawing apparatus according to claim 12 wherein said auxiliary drive motor is a positive displacement-type fluid motor, and said auxiliary drive means for regulating the pressure applied to the fluid motor to limit the torque applied to the auxiliary drawing drum.

15. A wire drawing apparatus according to claim 12 wherein said auxiliary drive motor is mounted on one of said drums and has a drive pinion rotatable about an axis parallel to and radially spaced from the axis of said drums, said auxiliary drive means including an annular gear on the other said drums concentric with the axis of said drums and meshing with said drive pinion.

16. A wire drawing apparatus according to claim 15 wherein said auxiliary drive motor is a positive displacement-type fluid motor, said auxiliary drive means including means for regulating the pressure applied to the fluid motor to limit the torque applied to the auxiliary drawing drum.

19. An improved method of drawing wire through a drawing die comprising forming a coil including a number of wraps in a single layer on a drawing drum assembly having coaxial inlet and outlet portions of like outer diameter rotatable relative to each other and forming an axially continuous drive surface, drivingly rotating the inlet portion of the drum in one direction with a torque sufficiently high to pull the wire through the drawing die and cause the drawn wire to wrap on the inlet portion of the drum assembly, forcing the coil of wire axially along the inlet portion of the drum assembly and onto the outlet portion and removing wire from the outlet portion as the wire wraps on the inlet portion of the drum assembly, pressing a roller against an outlet wrap of wire on the outlet portion of the drum assembly, and drivingly rotating one of the items comprising the roller and the auxiliary drum assembly with a torque sufficient to drive the outlet wrap of wire in said one direction and relative to the wraps of wire on the inlet portion of the drum assembly to tighten the coil on the drum assembly.