YARN BOBBIN WINDING MACHINE

Abstract: In a yarn bobbin winding machine, an automatic adjust­ ment mechanism is provided for preventing excessive build-up of the yarn at the two ends of the bobbin. A yarn guide beak is mounted on a holder which is carried on an adjustment rod which in turn is carried by a carriage which is connected to the traverse cam follower for movement therewith. A bell crank mechanism continuously moves the adjustment rod slidingly in a direction opposite to that in which the carriage is moving thereby slowing down the rate at which the yarn guide beak is traversing the bobbin relative to that of the traverse cam follower.

Description: YARN BOBBIN WINDING MACHINE Background of the Invention This invention relates to machines for winding yarns on bobbins. The invention relates particularly to a machine for winding a plurality of yarn ends simultaneously on a bobbin. In winding a plurality, for example, a group of eight ends of yarns on a bobbin, it is important that each yarn end be under the same tension and have the same length as the other ends of yarn in the group. As is well known, in winding the yarn ends on a flanged bobbin, a yarn guide carrying the group of yarn ends is moved by a traverse mechanism back and forth in a reciprocating manner relative to the bobbin axis. In the prior art mechnanism, as the yarn ends reach the bobbin flange and the yarn guide is reversed, the yarn package on the bobbin tends to build up to a greater extent at each end of the bobbin than in the area therebetween, resulting in a yarn package which has an increasingly larger diameter at each end. Conversely, the yarn package on the bobbin may not fill in completely at each end of the bobbin resulting in a yarn package which has a smaller diameter at each end. As viewed in cross section, such a yarn package will be flat in the central portion but will either slope upwardly or downwardly in a curving manner at each end. It will be seen from what has been said above that in a yarn package in which the diameter of the package increases or decreases at its opposite ends, some of the ends of yarn will be longer than the others, and each end of yarn will not have exactly the same length nor exactly the same tension as each other end of yarn. This is an undesirable condition and will show up as a defect in the construction in which the yarn package is being used, such, for example, as the reinforcing for industrial or hydraulic hoses. The undesirable build-up or fall-off at the ends of the yarn package could be avoided by the use of a traverse cam specially designed for that particular package. But it is highly impractical to have a different traverse cam for each yarn package as would be necessary since the package which results from the winding operation depends upon a number of variables, including type and denier of the yarn. Summary of the Invention A principal object of the present invention is to provide an improved machine for winding yarn ends on a bobbin. More specifically, an important object of the invention is to provide, for a yarn bobbin winding machine, a mechanism for avoiding build-up or fall-off of yarn at the opposite ends of the package which, unless avoided, produces a yarn package having a larger or smaller diameter at each of its ends than it has in the areas therebetween. Another object is to provide a traversing mechanism for a yarn bobbin winding machine which will produce a yarn package of constant diameter. The foregoing objects of the invention are achieved by the provision of a slide bracket which is carried by the traverse cam back and forth across the length of the bobbin. The pivot point of a bell crank is connected to and carried by the slide bracket. Supported for sliding movement in the slide bracket is an adjustment rod which is pivotally connected to one end of the bell crank. The other end of the bell crank is provided with a cam follower which rides in a fixed cam tract which is inclined in one direction, for example, upwardly from left to right. A yarn guide beak is mounted on and carried by the adjusting rod. In the preferred embodiment, the yarn guide beak extends all the way to the package so that there is no opportunity for the yarn ends to stray from their intended location on the package. As the slide bracket is moved back and forth in a reciprocating manner, it carries with it the bell crank. As the mechanism traverses, for example, from left to right, the cam follower riding in the fixed upwardly inclined track causes the bell crank to pivot continuously in a counterclockwise direction about its pivot point. This causes the upper end of the bell crank to move continuously to the left, thereby pushing the slidable adjustment rod continuously to the left relative to the slide bracket. This moves the guide beak continuously to the left relative to the slide bracket which is moving continuously to the right. A similar result is obtained when the slide bracket traverses from right to left. The cam follower, moving along the fixed downwardly inclined cam track, causes the bell crank to move continuously about its pivot point in the clockwise direction, thereby pushing the adjustment rod continuously to the right relative to the slide bracket which is moving continuously from right to left. As a result of the action described above, build-up of the yarn ends at the two ends of the bobbin is avoided, and a yarn package is obtained having a constant diameter throughout the length of the package. While the slope of the cam track is fixed for any particularly winding operation, the angle of inclination or slope of the cam track is adjustable so as to accommodate for different winding conditions and resulting yarn displacement behavior. Brief Description of the Drawings Figure 1 is a front elevational view of a yarn bobbin winding machine into which the improvement of the present invention may be incorporated. Figure 2 is a detailed view of a yarn separating device as seen looking in the direction of the arrow at point 2 of Figure 1. Figure 3 is a detailed view of a porcelain eyelet separator, as seen looking in the direction of the arrow at point 3 in Figure 1. Figure 4 is a side elevational view of the winding machine of Figure 1. Figure 5 is a detailed view of the tensioning device for the Godet wheels, as seen looking along the line 5-5 of Figure 4. Figure 6 is a top plan view of the machine of Figure 1. Figure 7 is a view looking in the direction of the arrow at point 7 of Figure 6. Figure 8 is a view looking in the direction of the arrow at point 8 of Figure 6. Figure 9 is a front elevational view showing the inclined cam track used in the adjustment mechanism provided by the present invention. Figure 10 is a detailed view showing the adjustment mechanism, including the cam track, bell crank, slidable adjustment rod, slide bracket, and holder for the yarn guide beak when the cam follower is in an intermediate position in its movement along the cam track. Figure 11 is a detailed view generally similar to Figure 10 but showing the adjustment mechanism when the track cam follower is at the rightmost end of trhe cam track. Figure 12 is a detailed view generally similar to Figure 10 and ll but showing the mechanism when the cam follower is at the leftmost end of the cam track. figure 13 is a detailed view showing the traverse cam, cam shoe, cam roller, guide piece, and slide bracket secured to the guide piece for travel back and forth relative to the bobbin. Detailed Description of the Preferred Embodiments In Figure 1, a plurality of ends of yarn Y, which for discussion will be assumed to be eight ends but which could be some other number, are pulled from a drum or other source of supply (not shown) through a yarn-end separator 11 and under a yarn support pin 12, as shown in detail in Figure 2. The eight ends of yarn Y are pulled in a downwardly inclined direction, protected by a cover or guide 13, and, as shown in Figure 3, pass through a porcelain eyelet separator 14 mounted in a bracket. The yarn ends then pass under, around, and over a pair of Godet wheels 16 mounted for rotation on skewed shafts 17. The Godet wheels are under adjustable tension by a mechanism shown in Figure 5, which will be described later. The eight yarn ends then travel upwardly, protected by a cover or guard 18, to a yarn bobbin 20 which is driven rotationally by a drive mechanism assembly identified generally by reference numeral 21. The bobbin drive assembly 21 includes a drive motor which may preferably be a variable speed DC motor. The drive mechanism, and the manner in which it drives the yarn bobbin 20, is well known and will not described in detail. Figure 4 is a side elevational view of the machine which is shown to be supported on adjustable feet 25. Figure 4 shows in dotted line the pair of Godet wheels 16 about which the yarn ends are drawn and the shafts 17 on which the Godet wheels16 are supported. As indicated, the shafts 17 are mounted in bearing 28 in a plate 27 secured to frame 26. The function of the Godet rolls is to keep the individual yarn ends separate from each other and to provide the desired tension to the yarn ends. Supported at the upper end of frame 26 on a base plate 29 is a housing 30 for the main traverse assembly. Each of the elements of the main traverse assembly shown in Figure 4 are shown and described in greater detail in other figures of the drawing, which will be discussed later. So far as Figure 4 is concerned, it will merely be said that the yarn traverse assembly includes a yarn bobbin 20, a beak guide 70, a beak guide holder 71, a yarn guide roller 61, a bracket 60, a traverse cam shaft 31, a traverse cam 32, and a cam track 54 plate. Figure 5, which is a view along the line 5-5 of Figure 4 looking in the direction of the arrows, shows the means for adjusting the tension on the Godet wheels 16. As there shown, mounted on each Godet shaft 17 is a flat pulley 80 around which a brake band 81, which may be of fabric, or rawhide, or other suitable material, is drawn. The brake band is connected at its two ends to a pair of brackets 82 and is tensioned by means comprising a roller 83, a spring 84, an adjustment stud 85, and an adjustment knob 86. Referring now to Figure 9, secured to fixed support base 29 is a cam track plate 54 having a cam track 53 which is inclined upwardly from left to right. Riding in cam track 53 is a cam-follower roller 52 which is connected to and carried by one end of a bell crank 50. As seen best in Figures 10-12, bell crank 50 is pivoted about a pivot stud 44 located at the lower end of an L-shaped mounting bracket 43, the upper end of which is secured to slide bracket 40. As seen best in Figure 13, slide bracket 40 is secured to a stud 134 which is integral with and projects laterally from a cam shoe 34, which rides in the cam track of the traverse cam 32. Traverse cam 32 is mounted on traverse cam shaft 31 which is driven by the main drive assembly. Mounted on stud 134 is a cam roller 33 and a guide piece 36 which rides in a guide plate 35. It will be seen that when the traverse cam shaft 31 is driven by the drive mechanism, the cam shoe 34, cam roller 33, guide piece 36 and slide bracket 40 are carried back and forth in a reciprocating manner. When slide bracket 40 is carried back and forth in a reciprocating manner, as just described, the bell crank mounting bracket 43 is also carried back and forth, and, since the bell crank 50 is fixed pivotally to mounting bracket 43 at pivot point 44, the bell crank 50 is also carried back. and forth. Supported for sliding movement in slide bracket 4 9 is an adjustment rod 41 which is pivotally connected at 51 to the upper end of bell crank 50. Thus, as bell crank 50 is carried back and forth, as described above, adjustment rod 41 is carried along with it. Secured to and carried by adjustment rod 41 is a bracket 60 on which a guide beak 70 is mounted. This will be discussed in more detail later in connection with the description of Figures 7 and 8. At this time, it will merely be pointed out that the yarn guide beak is secured to bracket 60 which is secured to adjustment rod 41 as a collar 45, the position of which on rod 41 is adjustable as by a set screw 46. In Figure 10, the adjustment mechanism is shown in the condition it assumes when the traverse mechanism is approximately at the center of its travel. Figure 11 illustrates the condition of the adjustment mechanism when the traverse mechanism has reached the right end of its travel. It will be seen that at the right-end limit of its travel, cam roller 52 has reached its most elevated position, i.e., the upper end of the upwardly inclined cam track 53. As a result, bell crank 50 has moved pivotally in a counterclockwise direction about pivot point 44 and has moved adjustment rod 41 to the left to its leftmost position. This may be seen by comparing the position of bracket 60 in Figure 11 with its position in Figure 10. In other words, as slide bracket 40 is carried by the traverse mechanism toward the right end of the bobbin, the bell crank 50 continuously moves adjustment rod 41 to the left, thereby slowing down the rate at which the guide beak 70 is moved to the right relative to the traverse mechanism. In Figure 12, the traverse mechanism and adjustment mechanism have reached the left end of their travel. As cam-follower roller 52 moved down downwardly-inclined cam track 53, bell crank moved continuously in a clockwise direction about pivot point 44, thereby pulling adjustment rod 41 continuously to the right relative to slide bracket 40. Thus, in Figure 12, the cam-follower roller 52 has reached its leftmost limit position, and the adjustment rod 41 has reached its rightmost position. Stated in other words, as the slide bracket 40 is carried to the left by the traverse mechanism, bell crank 50 continuously pulls adjustment 41 to the right, thereby slowing down the rate of travel of bracket 60 and guide beak 70 relative to the traverse mechanism. Reference is now made to Figures 7 and 8 which show how yarn guide beak 70 is mounted on bracket 60 which is mounted on adjustment rod 41. Bracket 60 is a generally triangular bracket having an extension 160 on which a pair of rollers 60 are mounted. Located between rollers 69 is an anti-rotation rod 120, the ends of which are mounted in frame side plates 38, as by screws 39, as seen in Figure 4. Bracket 60 is mounted on and supported by adjustment rod 41 for movement therewith in the axial direction of the bobbin. Mounted at the apex of bracket 60 is a yarn guide roller 61 over which the group of eight yarn ends pass on their way to the channelled front end 170 of yarn guide beak 70, as illustrated in Figure 6. Mounted in bracket 60 is a shoulder screw 90 on which are mounted a full-bobbin stop plate 91 and a holder plate 95 for the yarn guide beak 70. The position of the stop plate 91 is adjustable, as by screw 92 in slot 93. It will be seen that as the end 170 of yarn guide beak 70 rises as the yarn builds up on the bobbin, the apex of the stop plate 91 will come into engagement with stop rod 94 and this will be effective, as by electrical means, to shut off the drive to the bobbin. The yarn guide beak 70 is mounted adjustably, as by screws 74, to the beak holder plate 95 which is an angle plate, as seen best in Figure 8. Mounted in plate 95 is a pivot stud 96 on which is pivotally mounted a spring-biased lock plate 97 haing therein an L-shaped slot 98. A stud 68, mounted in bracket 60, is ordinarily positioned within the longer leg of slot 98. When, during bobbin changes, the yarn guide beak 70 is manually raised to an elevated position, beak holder 95 pivots counterclockwise on shoulder screw 90, as viewed in Figure 8, and stud 68 slides down the long leg of slot 98 and enters the short leg. This locks the spring-biased plate 97 and prevents the guide beak 70 from falling down during bobbin change. In some prior art winding mechanisms, a cam track and bell crank have been used, not for the purpose of assuring a yarn package of constant diameter as is the purpose of the present invention, but rather for the purpose of providing a tapered yarn package, i.e., a package having inwardly inclined edges. Tapered yarn packages have been formed in the prior art by using a bell crank having a cam follower which rides in a cam track, the slope of which is constantly changed during traverse in response to sensing a diameter of the package. In other words, in response to the increase of the diameter of the package, the angle of inclination of the cam track is increased in such manner that traverse of the yarn guide beak is stopped and reversed at a limit position which is constantly changing, such limit occurring at an ever increasing distance from the end of package. While a bell crank and cam track are used in the present invention, they are used for entirely different purpose and in an entirely different manner than in the prior art. As has already been made clear, the purpose in the present invention is to achieve a yarn package of constant diameter. During the winding of any particular bobbin with the yarn selected, the cam track is fixed. Its slope is, however, adjustable manually to accommodate for different yarn winding conditions. It should also be pointed out that in the preferred form of the present invention, the yarn guide beak extends all the way to the package. In this respect, the yarn guide beak is different from that of the usual prior art winding machine. In the ususal prior art machine, the yarn guide beak does not extend inside the imaginary line drawn between the outer edges of the two flanges of the bobbins parallel with the bobbin axis. Where the yarn guide beak does not extend all the way to the package, there is the danger that the yarn ends will stray from their intended location on the package. This possibility is avoided in the mechanism of the present invention by having the yarn guide beak extend all the way to, and ride on, the yarn package as it is built up.

Claims: WHAT IS CLAIMED IS: 1. In a yarn bobbin winding machine having a traverse cam and a traverse cam follower, an adjustment mechanism comprising: a. a slide bracket mounted for traverse movement with the traverse cam follower; b. a bell crank mounted on said slide bracket for pivotal movement relative thereto; c. a cam track fixed to the frame of said winding machine and inclined relative thereto; d. a cam follower in said cam track, said cam-track follower being carried by one of the arms of said bell crank; e. an adjustment rod mounted for sliding movement in said slide bracket; f. means connecting the end of the other arm of said bell crank pivotally to said adjustment rod; g. a yarn guide secured to said adjustment rod for movement therewith; ; h. said cam track being so sloped that said bell crank moves said adjustment rod'relative to said slide bracket in a direction opposite to that in which said slide bracket is being moved by said traverse cam follower. 2. Apparatus according to Claim 1 wherein the angle of inclination of said cam track is adjustable manually for different yarn winding conditions. 3. Apparatus according to Claim 1 wherein said inclined cam track is straight, thereby to cause said bell crank to pivot continuously in one direction during travel of the cam-track follower in one direction, and to cause said bell crank to pivot continuously in the other direction during travel of the cam-track follower in the other direction. 4. Apparatus according to Claim 1 wherein said yarn guide is adjustably secured to said adjustment rod. 5. Apparatus according to Claim 1 wherein said yarn guide extends all the way to the yarn package being formed on the bobbin. 6. Apparatus according to Claim 3 wherein said cam track is inclined upwardly from left to right and said bell crank pushes said adjustment rod leftward as said slide bracket moves rightward and pulls said adjustment rod rightward as said slide bracket moves leftward. 7. In a yarn bobbin winding machine having a traverse cam and a traverse cam follower, an adjustment mechanism for producing a yarn package of constant diameter, said adjustment mechanism comprising: a. a slide bracket mounted on the traverse cam follower for transverse movement therewith; b. a bell crank pivotally mounted on said slide bracket, said bell crank havng upper and lower arms; c. an inclined cam track fixed to the frame of said winding machine; d. a cam follower in said cam track, said cam-track follower being carried by said lower arm of said bell crank; e. an adjustment rod mounted for sliding movement in said slide bracket; f. means connecting the upper arm of said bell crank pivotally to said adjustment rod; and g. a yarn guide secured to said adjustment rod for movement therewith in the transverse direction of said bobbin, whereby said adjustment rod is moved relative to said slide bracket by said bell crank in a direction opposite to that in which said slide bracket is being moved by said traverse cam follower. 8. Apparatus according to Claim 7 wherein said yarn guide is adjustably secured to said adjustment rod. 9. Apparatus according to Claim 8 wherein said cam track is inclined upwardly from left to right and said bell crank pushes said adjustment rod leftward as said slide bracket moves rightward and pulls said adjustment rod rightward as said slide bracket moves leftward. 10. In a yarn bobbin winding machine: a. a traverse cam; b. a traverse cam follower; c. a carriage coupled to said traverse cam follower for movement therewith in the axial direction of the bobbin; d. an element carried by said carriage and mounted thereon for movement relative thereto in the axial direction of said bobbin; e. a yarn guide mounted on said element; and f. means for moving said element relative to said carriage in a direction opposite to that in which said carriage is being moved by said traverse cam follower 11. Apparatus according to Claim 10 wherein said element carried by said carriage is an elongated rod mounted for sliding movement in said carriage. 12. Apparatus according to Claim 11 herein said means for moving said rod relative to said carriage comprises: a. a bell crank pivotally secured to said carriage; b. an inclined cam track fixed to said machine; c. a cam track follower carried at one end of said bell crank; and d. means pivotally connecting the other end of said bell crank to said rod. 13. Apparatus according to Claim 12 wherein means are provided for manually adjusting the angle of inclination of said cam track to accommodate to different yarn winding conditions. 14. Apparatus according to Claim 13 wherein the yarn guide extends all the way to the package being formed on the bobbin.

Inventors: IANNUCCI, VINCENT A.
Applicants: ROCKWELL INTERNATIONAL CORPORATION
Application year: 1983
Main classification: B65H57
IPC codes: B65H54, B65H57