Wire containment apparatus for wire drawing machines
A wire drawing machine is provided with a pressure roller in the form of a roller sized to extend substantially across the width of the capstan and engage multiple turns of wire thereon in a lower quadrant on the exit side of the capstan. The pressure roller is mounted for pivoting about a horizontal axis parallel to the axis of the capstan, and for automatic angular positioning and alignment as contact is made with the wraps of wire on the capstan.
 This application claims priority to U.S. Provisional Patent Application S/N 60/193,996, filed April 1, 2000.BACKGROUND OF THE INVENTION
 1. Field of Invention
 The present invention relates to wire containment apparatus suitable for use on conventional in-line wire drawing machines.
 2. Description of Prior Art
 Prior wire containment apparatus for in-line wire drawing machines utilizing a non-tapered capstan include a final contact pressure roller that is adapted for engaging the last wrap of wire on the capstan in order to clamp the wire in position on the capstan and develop traction between the capstan and the wire to draw the wire through the die. However, there are several drawbacks and disadvantages associated with such prior final contact wire containment rollers.
 Such rollers must apply a substantial pressure onto the last wrap to firmly hold the wire on the capstan and develop the necessary traction therebetween for pulling the wire through the draw die. Consequently, these rollers must be changed when running wire of substantially different sizes in order to precisely match the roller size with the wire size, and to develop and maintain the desired wire position and pressure. This results in substantial expense for changing and setup time for each different size wire run on the machine. In an effort to minimize this setup time, and to provide for operator safety, these final contact rollers are positioned in an upper quadrant of the capstan to provide ease of operator viewing and alignment with the last wire wrap on the capstan. Consequently, the wire tends to sag or drop substantially as it exits from the lower quadrant of the capstan. This results in an associated wire length and weight that the speed compensating arm must accommodate in controlling the operation of the capstan.Summary of the Invention
 The general aim of the present invention is to provide a new and improved wire containment apparatus for in-line wire draw machines utilizing non-tapered capstans which eliminates the aforementioned drawbacks and disadvantages or prior wire containment final contact rollers.
 An objective of the invention is to provide apparatus which reduces the pressure needed to develop the necessary traction between the wire and the capstan in order to assist in avoiding flattening or deformation of the drawn wire, and which reduces the operating pressures in the apparatus therefor.
 Another objective of the invention is to reduce the need for changing the final contact rollers of prior machines for different wire sizes, thereby reducing the expense of the machine and setup time when changing from running different wire sizes.
 A more detailed objective is to achieve the foregoing by providing final contact wire containment apparatus that is self-adjusting and adapted for use with wire of different sizes.
 Yet another objective is to provide wire containment apparatus which reduces the sagging of wire as it exits the capstan, to reduce the length and weight of the wire reflected to the speed compensating arm. This enables the compensating arm to operate at lower pressures, and with increased sensitivity.
 These and other objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.Brief Description of the Drawings
 FIG. 1A is a front view of one-type of in-line wire draw machine showing a conventional prior art final contact wire containment apparatus.
 FIG. 1B. is a front view of the wire draw machine of FIG. 1A but showing a unique wire containment apparatus according to the present invention.
 FIG. 2 is a top view of the machine of FIG. 1B taken along the line 2-2 of FIG. 1B with portions of the housing shown removed.
 FIG. 3 is a right side view of the wire draw machine of FIG. 1B taken along the line 3-3 of FIG. 2.
 FIG. 4A is a rear view of the back wall of the capstan housing and certain components thereof including components of the prior art wire containment apparatus of FIG. 1A
 FIG. 4B is a rear view of the back wall of the capstan housing and certain components thereof including components of the improved wire containment apparatus of the present invention of the embodiment of FIG. 1A as seen substantially along the line 4-4 of FIG. 3.
 FIGS. 5A and 5B are top and side views, respectively, of the capstan and certain other components, including the wire containment apparatus of the prior art configuration of FIG. 1A and the present invention embodiment of FIG. 1B.
 FIG. 6 is an enlarged perspective view of the wire containment apparatus embodiment of the present invention shown separate from the wire draw machine for purpose of clarity of understanding.
 FIGS. 7, 8 and 9 are rear, right side and top plan views, respectively, of the separate wire containment apparatus shown in FIG. 6.
 FIG. 10 is a cross-sectional view taken along the line 10-10 of FIG. 9.
 While the invention is susceptible of various modifications and alternative constructions, a certain illustrated embodiment has been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention.DETAILED DESCRIPTION OF THE INVENTION
 For purposes of illustration, the present invention is shown in the drawings as wire containment apparatus 200 (see FIGS. 6-9) in connection with a wire drawing machine 10B (FIG. 1B) equipped with an integral turntable. As will be apparent, the wire containment apparatus of the present invention is equally suitable for use an other types of wire draw machines.
 Also shown in the drawings is an inline wire drawing machine 10A (FIG. 1A) which is substantially similar to machine 10B except as described further below in connection with the wire containment apparatus of the present invention; the machine 10A being provided with a conventional prior art wire containment apparatus for purposes of comparison and contrasting with the present invention; with the same numeral identifiers being used for the same parts, components, assemblies, etc. for the machines 10A and 10B.
 The basic structure, function and operation of the wire draw machine 10A, and therefore machine 10B with the exception of the wire containment apparatus, has been fully explained and described in U.S. Pat. No. 6,125,675; a the copy of which is attached hereto and incorporated herein and made a part hereof herein by reference.
 Briefly, electric motor 22 (FIG. 2) power rotates capstan 20 with wire 11C wrapped therearound to draw the wire from the coil of wire 11 and through the draw die 12. From the capstan, the wire is pulled around a speed compensating roller/arm assembly 36, and is drawn into a wire using machine or station (not shown) via power rotated rollers 38.
 In accordance with the present invention, the wire containment apparatus 200 includes a roller assembly 210 (FIG. 1B) adapted for automatic position adjustment and self-alignment of a roller 222 against the wire 11C wrapped around the capstan 20. As a result, and as further described below, the wire containment apparatus 200 of the present invention is less expensive than conventional prior wire containment apparatus, is more easily positioned by the machine operator, and results in a wire draw machine that can operate at greater efficiency and with improved capacity.
 Briefly, the wire containment apparatus 200 comprises an actuator 220 that is operatively connected to the roller assembly 210 for swinging the roller 222 about an axis “AA” (FIG. 1B) that is parallel to the rotational axis of the capstan, and into and out of engagement with the wire 11C on the capstan 20. The roller is mounted in the roller assembly for pivoting about orthogonal axes “BB” and “CC” to effect automatic angular position adjustment and selfalignment into pressure engagement with the wire wrapped on the capstan as the roller swings upwardly (as viewed in FIG. 1B) toward the capstan. Thus, the freedom of movement of the roller assembly automatically compensates for tapering of the capstan resulting from wear, and for dimensional and angular deviations in size and positioning of the capstan and the wire containment apparatus resulting from normal manufacturing tolerances.
 In carrying out the invention, the actuator 220 is mounted to a stationary frame or structural member of the machine 10B, and is operatively connected to the roller assembly 210 through a linkage assembly 230. The actuator assembly shown comprises a conventional-type actuator having an actuator housing connected to extension member 224 of the back wall 18 of the capstan housing via threaded fasteners 226, an internal piston (not shown) operative for linear movement between two stroke ends in response to regulated actuating pressure supplied through hose 228 from, and a piston rod 232 connected thereto for linear movement as indicated by arrow EE (FIG. 7) between the two stroke ends with the actuator piston. In the present instance, the actuator is a single-acting pneumatic actuator which is spring biased in one direction, such as for disengagement between the roller and the wire on the capstan, and is provided with a conventional elastomer diaphragm (not shown) connected to the piston, the diaphragm and piston being pressure responsive in the other direction to overcome the spring bias and stroke the piston.
 The linkage assembly 230 includes a torque transfer stepped shaft 234 extending through back wall 18 and tube 235 and rotary supporting bushing 236 or bearing fixed therein, and a lever 238 connected to the rear end of the shaft via fastener 240 extending through aligned openings in bearing washer 242 and the lever and threaded longitudinally into the end of the shaft. The lever extends radially from the shaft and is pivotally connected to clevis 244 mounted to the free end of the piston rod with a pivot pin 246 for establishing a pivoting connection therebetween. With this arrangement, the lever swings about axis AA as indicated by arrow FF in FIG. 7, as the piston and piston rod stroke linearly along EE in the actuator, in turn causing the shaft 234 to turn through an angular rotation within the limits established by the geometric parameters of the piston stroke length and radial distance between pivot pin 246 and axis AA.
 The forward end of the torque transfer shaft 234 is connected to a support block 250 of the roller assembly 210 for pivoting of the support block about axis “AA” with the shaft. In the embodiment shown, the shaft extends substantially through the support block and is secured therein with fastener 240 extending through bearing washer 242 and threaded longitudinally into the forward end of the shaft. In this instance, the shaft and support block are further secured for torque transfer purposes via key 252 located in keyway 254 extending radially and longitudinally into the shaft and support block.
 The roller 222 is mounted in bearings 258 located in support arms 260 for freely rotating about rotational axis DD extending longitudinally therethrough. To effect 2-degree of freedom of roller angular positioning on orthogonal axes, the arms 260 are connected with a center brace 262 that is in turn pivotally connected to a center block 264 via pivot pin 266. The center block is in turn pivotally connected to the support block via pivot pin 268 in an arrangement commonly known as a pivoting knuckle. These pivot pin installation arrangements may take any of a number of suitable embodiments, such as shown in FIG. wherein pin 268 is pressed into an interference-fit opening 270 in the support block, with the pin pivotally extending through an optional bushing 272 pressed into the center block and a retaining ring 274 or other suitable arrangement maintaining the center block in position on the pin. Similarly, the pin 266 is held in position with retaining rings 281 for a free-floating pivot pin connection, or alternately may be pressed though interference-fit openings 276 extending through the center block and through an optional bushing 278 in the brace. In any event, the particular pivot pin arrangement utilized permits such two degree of angular freedom of movement.
 In preferred embodiments, limitations are established for the two-degree of freedom angular movement of the roller. In the embodiment shown, the dimensional clearance between the floor and the capstan limit free rotation about the CC axis. Alternately, positive angular stops are established between the support and center blocks. Limitation of rotation about the BB axis is established by a pair of threaded fasteners 291 and associated jam nuts, located on each side of the center block, and threaded through ears welded thereto.
 With this arrangement, the roller freely rolls about its axis of rotation DD, and is pivotally moveable within established limitations about the pin 266 along the BB axis and the pin 268 along the CC axis, for automatic alignment and engagement with the wire on the capstan.
 As shown in FIG. 5B, the width of the roller 222, along its longitudinal axis DD, is sized at close to the inside width of the capstan 20 for engaging either all of the wraps 11C of wire on the capstan, or for engaging all but one or two wraps of wire, and for maintaining even pressure on such wraps of wire. In the latter instance, provision is made for adjusting the position of the roller assembly for indexing of the roller on the wraps of wire; such as is sometimes useful when running wire of substantially different sized on the same machine, and in instances when the wire tend to not index on the capstan. Provision for indexing or adjusting of the position of the roller along the AA axis with respect to the sides of the capstan can be accomplished with any suitable arrangement such as simply with slots through which fasteners 226 extend, or repositioning of the support block on the shaft 234.
 Advantageously, maintaining an even pressure on all wraps of the wire, as opposed to maintaining pressure of the last wrap as conventional prior wire containment apparatus, permits the use of less pressure for maintaining the wire sufficiently snugly against the capstan for drawing the wire through the die. In other words, the wire is maintained snugly against the capstan for a substantially greater distance (measuring the wrapping length of the wire around the capstan) as compared with prior wire containment apparatus. As a result, the wire containment apparatus 200 results in greater traction developed between the capstan and the wire.
 In further keeping with the invention, the wire containment apparatus of the present invention is preferably located in the quadrant proximate the exit point of the wire from the capstan. To this end, in the embodiment shown, the wire containment apparatus is located in the lower quadrant opposite the speed compensating arm. As a result, the wire is held firmly against the capstan until just prior to unwrapping from the capstan.
 Those skilled in the art will appreciate alternate embodiments that fall within wire containment systems of the present invention. By way of example only, it will be understood that the actuator may be of any suitable type operatively connected to the roller assembly with a suitably designed linkage assembly for controlling position of the roller assembly with regard to the capstan as described. By way of example only, a double-acting actuator responsive to pressure applied from both sides of the piston, a piston-seal actuator (as opposed to a diaphragm-type actuator), a hydraulic actuator, a mechanical or electromechanical actuator provided with electric motor, and other types of actuators and associated linkage assemblies may be substituted and used with in the scope of the invention.
 Wire containment system of the present invention may be used on other conventional and non-conventional wire drawing machines having a capstan, and in which there is a need to hold the wire against the capstan to develop the necessary traction for drawing the wire through one or more draw dies.
 With the foregoing wire containment system, less pressure is applied to each wrap of wire, while developing the same or greater traction of conventional prior roller arrangements that engage the last wrap of wire. Positioning the roller proximate the speed compensator arm reduces the “free drop” of the wire as it exits the capstan, allowing the capstan to be positioned closer to the floor, and reduces the drag on the speed compensating arm since it does not need to carry as much wire weight or hold the wire off the floor, permitting to operate with less air pressure and at greater sensitivity. Such reduced wire drop also allows for lower wire entry and exit on the machine, reducing the overall height of the machine. Wire of substantially different sized can be run on the machine without having to change the roller. And the roller hereof eliminates the task of aligning the prior roller with the last wire wrap prior to engaging the pressure roller, by virtue of being adapted for pivoting about orthogonal axes as it is brought into engagement with the wire on the capstan resulting in automatic alignment of the roller 222 along the entire width of the capstan.
1. A wire drawing machine comprising:
- a draw die;
- a capstan mounted for rotation about a horizontal axis and positioned for drawing wire through the draw die, the capstan having an upper wire-entry side and a lower wire-exit side; and
- a roller connected for pivoting about a horizontal axis parallel to the axis of the capstan and about a second axis orthogonal thereto for engaging wire on the lower exit side of the capstan, the roller being sized to substantially overlap the width of the capstan and engage the wire wrapped thereon.
International Classification: B21C001/02;