WIRE DRAWING MACHINE

Abstract: A wire drawing device for drawing a plurality of strands (a-g) simultaneously in a downstream direction through a plurality of groups of dies (10a-10g), there being one die (10) for each strand. Each group of dies (10a-10g) is held in a retaining means (16) comprising first and second portions (15, 17) adapted for movement toward and away from one an­ other. When the retaining means (16) is in the open position, wherein the portions (15, 17) have been moved away from each other, any one of the plurality of dies (10a-10g) may be removed without removing or displacing other dies in the same group. when the portions (15-17) are moved toward each other, they overlie at least partially the dies (10a-10g) in the group and thereby retain them in position.

Description: The present invention is directed to a wire drawing device according to claim 1 and a method for replacing broken strands which break during drawing, according to claim 8. Wire drawing devices of the general type disclosed herein have been known for many years. They comprise a plurality of capstans over which the wire being drawn passes. Normally, the wire loops at least once around each capstan and the dies are located between these capstans. Since a plurality of strands is drawn at the same time, the capstans are relatively long in the axis direction and often 7 or 8 such strands are wrapped around each capstan. Between the capstans there is a group of dies, each group containing a plurality of dies between the capstans, the number of which corresponds to the number of strands being drawn. As is frequently the case, one or more strands break during the drawing operation. When a strand breaks, the operator must take the end of the strand and pass it through the opening of the corresponding die. He then must wind it around the next capstan and rotate the capstan by causing the machine to move slightly. He then must perform the same steps on the next die and capstan, and so on until he has completely rethreaded the broken strand. Then, the machine may be restarted and normal operation resumed. If the broken strand happens to be other than the outermost one, the operator must work with his arms substantially extended. This creates a great strain on him and makes the job quite awkward. This is especially true when the wires are very fine and threading is difficult. Moreover, such fine wires might easily be broken by the movement of the operator's arms in the course of trying to thread a previously broken strand through the various dies and capstans. It is an object of the present invention to provide a means and method, whereby the operator of the machine may easlily replace and rethread a broken strand, no matter where it is, without having to strain his arms and without danger of breaking other strands. Solution of this object is achieved by what is claimed in claims 1 and 8. In essence, the invention consists of providing means, whereby the broken strand and its corresponding die, may be easily moved to the front of the device for ready access by the operator. In its broadest aspect, the present invention comprises a filament drawing device having a source of a plurality of strands to be drawn. There is at least one die group, there being one die in the group for each strand. Means for drawing the strands through the die group or groups is also provided. Each group of dies is held in a retaining means which comprises first and second portions; these portions are capable of movement relative to one another between an open position and a closed position. In the closed position, the portions at least partially overlie the dies and retain them in position. When the portions are moved to their open position, sufficient space between them is provided so that one or more dies can be removed therethrough. Preferably, each portion has a recess therein, into which a part of each of the dies fits. Thus, when one of the plurality of strands breaks, the operator stops the machine. He then proceeds to the die group furthest upstream and moves the portions to their open position. The die corresponding to the broken strand is then removed through the opening formed, the remaining dies are slid in a direction transverse to the direction of movement of the strands away from the operator, and the removed die is placed in the outermost position which is nearest to the operator. By this movement the strand is carried along, so that it now becomes the outermost strand. If necessary, the broken strand is then passed through the moved die, looped around the downstream capstan, and the same procedure repeated for each die group. Thereafter, the machine can be restarted. Because the operator is working primarily on dies and strands which are closest to him, the possibility of breaking other strands is minimized. Moreover, the strain of working with arms extended is eliminated. The following is a more detailed description of the present invention, taken in conjunction with the accompanying drawings, in which: Fig. 1 is a schematic view, partly in section, of a prior art device; Fig. 2 is an enlarged perspective view of a group of dies and a capstan in accordance with the prior art; Fig. 3 is a plan view, partly schematic, partly in section, of a device in accordance with the present invention; Fig. 4 is a view similar to that of Fig. 3, but in elevation; Fig. 5 is a partly schematic, partly sectional view of two capstans and an intermediate group of dies in accordance with the present invention; Fig. 6 is a sectional view along line A-A of Fig. 5; Fig. 7 is an end view of the device as shown in Fig. 6 with the movable projection in open position; Fig. 8 is a view similar to Fig. 7 with the movable projection in closed position; and Fig. 9 is a sectional view along line B-B of Fig. 5. The device and method according to the present invention will be described in terms of the drawing of wire. However, its scope is substantially broader than that and, in fact, will include the drawing of any ductile material. Referring particularly to Fig. 3 and 4, the device of the present invention comprises wire supply reels 1, a housing 25, capstans 24, and dies 10-a to 10-g. Input guide roller 8 and input spacing rods 91-98 aid in distributing wires over the surfaces of the capstans. Exit spacing rods 100 and exit capstan 24 perform substantially the same function at the point at which the drawn wires leave housing 25. Exit capstan 24 may also function as a means for drawing wires. Tensioning means 6 and a take-up reel 5 are provided for completion of the drawing operation. Drawing stages 30 to 39 are each comprised of capstan and dies. There is one die for each wire. In Fig. 6 a detail of a die holder 11 for the dies 10 is shown. There is one die 10 for each wire 6 arranged substantially in a line adjacent to one another. They are held in place by a stationary projection 15a on a stationary portion 15 and a movable projection 17a on a movable portion 17. Movable portion 17 is positioned by securing nuts 18 in elongated slots 19. As is shown in Fig. 7 and 8, a first holder member 16a carries stationary portion 15 and a second holder member 16b carries movable portion 17. A locking plate 21 is mounted on stationary portion 15 at a pivot 22. A locking screw 23 (see Fig. 5) is actuated by locking nut 18. In Fig. 7, movable portion 17 is shown in its open position, wherein any one of the dies 10 may be removed from the die holder 16. In Fig. 8, movable portion 17 is shown in its closed position, wherein dies 10 are retained against removal or inadvertent movement. Obviously, although the specific embodiment recites portion 15 as being stationary and portion 17 as being movable, the reverse could be true or both could be made movable. It is only necessary that there be provision for relative motion between portions 15 and 17 such that, when the portions are at their maximum distance apart, there is sufficient room for removing one or more of the dies 10. In normal operation of the device, wires are drawn off supply reels 4 and pass over input guide roller 8. They pass through the passages formed by adjacent input spacing rods 90 through the first of dies 10 and are looped at least once around the first of the capstans. Wires then proceed serially through successive drawing stages 30 and exit housing 25 through the passages between adjacent exit spacing rods 100, pass over exit capstan 24, and are looped therearound at least once. Wires then pass over tensioning means 6 and are wound onto take-up reel 5. When one of the wires breaks, as commonly happens during operation of the device, the operator stops the machine and loosens locking nut 18 on the die holder 11 which is furthest upstream. Locking plate 21 is pivoted to the position shown in Fig. 8. Securing nuts 18 are loosened and movable portion 17 is slid away from stationary portion 16 to the position shown in Fig. 7. The one of dies 10, through which the broken strand passes, is removed and the remaining dies slid to the right as shown in Fig. 6. Die 10 containing the broken wire is moved to the position at the extreme left of Fig. 6, a point which is convenient to the operator. Wire passing therethrough is moved to the corresponding position on capstan, which is not difficult, since the surfaces are preferably smooth. Movable portion 17 is then slid toward stationary portion 16 so that the position shown in Fig. 8 is achieved. Dies 10 are securely held in stationary groove 15b and movable groove 17b. Locking plate 21 is then swivelled around pivot 22 to its closed position and locking nut 18 is tightened to securely hold dies 10 in place. The foregoing procedure is repeated for each of stages 9. In those stages downstream of the actual break, the operator must also thread wire 6 through die 10 before replacement thereof; otherwise, the steps are substantially the same as previously described. In the embodiment of the device wherein input spacing rods 90 and/or exit spacing rods 100 are provided when a break occurs, the operator must first move wires, so that the broken wire is in the passage between the outermost two rods. At the same time, the remaining wires are moved inwardly to take up the passage vacated by the broken wire. A similar procedure is followed for the passages between exit spacing rods 100. It can be seen from the foregoing that the present invention provides a device and method whereby the broken wire can be rethreaded at the points on the device which are closest and most convenient to the operator. This not only makes the task easier, but also minimizes the chances of breaking other wires, while rethreading the one which has already broken. Grooves 15b and 17b are, of course, preferred to the same length. This length is advantageously in accordance with the formula L = D (N + 1), wherein L is the length of grooves 15b and 17b, N is the number of dies 10 (corresponding to the number of wires) and D is the diameter of one of dies 10. The arrangement of supply reels 1 can be varied considerably, but it is advantageous to prevent contact between wires after they are drawn from supply reels 1. One suitable arrangement is shown in Fig. 3 and 4. Supply reels 1 are arranged on stand 7 spaced apart in a line which is perpendicular to their respective axes. This provides a series of angles at which wires are drawn so that they do not contact one another at any point once they have left their respective supply reels. Similarly, in Fig. 2, it can be seen that the spacing as provided by rods 90 also serves to separate wires from one another and aids in preventing contact.

Claims: A wire drawing device comprising: a source of a plurality of strands (a to g) to be drawn in a downstream direction; at least one die group (30) comprising a plurality of seperate dies (10a to 10g), there being one die (10) in said group for each of said strands and each die (10a to 10g) being movable in a transverse direction to said downstream direction, whereby, when one of said dies is removed, the remaining dies may be moved in the transverse direction such that they abut each other; means (5, 6, 24) for drawing said strands through said die group; and retaining means (16a, 16b) for each said die group, each said retaining means (16) comprising a first portion (15) and a second portion (17) adapted for movement relative to one another between an open position and a closed position, said retaining means (16), when in its open position, having its first and second portions (15, 17) spaced apart a greater distance than in said closed position such that when said retaining means (16) is in said closed position, they at least partially overly said die group (30) such that said die group (30) is positively held in said wire drawing device, and, when said retaining means (17) is in said open position, any of said die (10a to 10g) in said group (30) is arbitrarily removable without removing any other die (10a to 10g) in said group (30). The device of claim 1, characterized in that said first portion (15) comprises a first recess (15b) which opposes a second recess (17b) in said second portion (17), said recesses (15b, 17b) extending in a transverse direction to said downstream direction and adapted to receive said die group (10) when said retaining means (16) is in said closed position. The device of claim 1 or 2, characterized in that a plurality of said die groups (10) is provided and said means for drawing is adapted to draw said strands through said plurality of die groups serially. The device of anyone of the preceeding claims, characterized in that said means for drawing comprises a power driven capstan (12) downstream of at least one said die group (30), said capstan (12) is adapted to receive a loop of each of said strands (a to g). The device of anyone of the preceeding claims, characterized in that a plurality of rods (91 to 98, 101 to 108) is located upstream of said die group (30), said rods (91 to 98, 101 to 108) having axes substantially perpendicular to a plane substantially passing through said strands, said rods (91 to 98, 101 to 108) being spaced apart in a direction parallel to said plane to form passages therebetween, each of said passages adapted to have one of said strands pass therethrough. The device of claim 4, characterized in that said capstan (12) is provided with a surface which permits said strands (a to g) to slide axially thereover. The device of of anyone of the preceeding claims, characterized in that said strands (a to g) are metallic wires. A method of replacing a broken strand in the wire drawing device of anyone of claims 1 to 7, said method comprising the steps of: stopping said means for drawing (5, 6, 24); moving said retaining means (16) retaining a first die group (30) which is furthest upstream into said open position; removing a die (10) having said broken strand (a to g); moving the remaining dies (10a to 10g) in said first die group (30) in a transverse direction to said downstream drawing direction away from an operator; passing said broken strand through said removed die (10); inserting said removed die together with the inserted strand back into said die group (30) at a position nearest to said operator; connecting said broken strand to said means for drawing (5, 6, 24); moving said retaining means (16) retaining the first die group (30) into said closed position; and repeating the above steps for each said die groups following in downstream direction. The method of claim 8, characterized in that said inserting step comprises opening a locking means (18, 21, 23) at an end of said first die group (30) nearest said operator, inserting said removed die, and closing said locking means (18, 21, 23). The method of claim 8 further characterized by moving said broken strand to a passage between two adjacent rods (90, 100) which is nearest said operator and having axes substantially perpendicular to a plane substantially passing through said strands (a to g).

Inventors: IURA, KAZUO, YAMAMOTO, AKIRA, YOSHIDA, KINZI
Applicants: SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1988
Main classification: B21C1
IPC codes: B21C3, B21C1