WO2001081222A2

WO2001081222A2 - Method and apparatus of winding a fibrous strand

Info

Publication number: WO2001081222A2
Application number: PCT/US2001/010430
Authority: WO
Inventors: Joseph A. Adcock; Keith B. Richey; Clark T. Forbes; James H. Sears; Eugene V. Galloway
Original assignee: Owens Corning
Priority date: 2000-04-20
Filing date: 2001-04-02
Publication date: 2001-11-01
Also published as: WO2001081222A3; AU2001249713A1

Abstract

A method of winding a fibrous strand (14) includes mounting a first collet (22a) and a second collet (22b) on a rotatable turret (64), and rotating the first collet to wind the strand using a cam (30) to build a first package (20). The stand is transferred from the first collet to the second collet to build a second package on the second collet, and the turret is rotated while transferring the strand from the first collet to the second collet.

Description

METHOD AND APPARATUS OF WINDING A FIBROUS STRAND

TECHNICAL FIELD

This invention relates to the production of glass fibers, and in particular, to winding a glass fiber strand to form packages. More particularly, this invention relates to a method of winding a fibrous strand by automatically transferring the strand from one collet to another collet.

BACKGROUND OF THE INVENTION Mineral fibers are used in a variety of products. The fibers can be used as reinforcements in products such as plastic matrices, reinforced paper and tape, and woven products. During the fiber forming and collecting process numerous fibers are bundled together as a stand. Several strands can be gathered together to form a roving used to reinforce a plastic matrix to provide structural support to products such as molded plastic products. The strands can also be woven to form a fabric, or can be collected in a random pattern as a fabric. The individual strands are formed from a collection of glass fibers, or can be comprised of fibers of other materials such as other mineral materials or organic polymer materials. A protective coating, or size, is applied to the fibers which allows them to move past each other without breaking when the fibers are collected to form a single strand. The size also improves the bond between the strands and the plastic matrix. The size may also include bonding agents which allow the fibers to stick together, thereby forming an integral strand.

Typically, continuous fibers, such as glass fibers, are mechanically pulled from a feeder of molten glass. The feeder has a bottom plate, or bushing, which has anywhere from 200 to 10,000 orifices. In the forming process, the strand is wound around a rotating drum, or collet, to form, or build, a package. The completed package consists of a single long strand. It is preferable that the package be wound in a manner which enables the strand to be easily unwound, or paid out. It has been found that a winding pattern consisting of a series of helical courses laid on the collet builds a package which can easily be paid out. Such a helical pattern prevents adjacent loops or wraps of strand from fusing together should the strand be still wet from the application of the size material. The helical courses are wound around the collet as the package begins to build. Successive courses are laid on the outer surface of the package, continually increasing the package diameter, until the winding is completed and the package is removed from the collet. The waywind is the number of rotations of the collet during the traverse of the cam follower and guide eye from one end of the package to the other (usually a number between 2 and 4). A strand reciprocator guides the strand longitudinally back and forth across the outer surface of the package to lay each successive course. A known strand reciprocator is the spiral wire type strand oscillator. It consists of a rotating shaft containing two outboard wires approximating a spiral configuration. The spiral wires strike the advancing strand and direct it back and forth along the outer surface of the package. The shaft is also moved longitudinally so that the rotating spiral wires are traversed across the package surface to lay the strand on the package surface. While building the package, the spiral wire strand oscillator does not contact the package surface. Although the spiral wire strand oscillator produces a package that can be easily paid out, the package does not have square edges. A known strand reciprocator which produces square edged, cylindrical packages includes a cam having a helical groove, a cam follower which is disposed within the groove and a strand guide attached to the cam follower. As the cam is rotated, the cam follower and strand guide move the strand longitudinally back and forth across the outer surface of the rotating package to lay each successive course. A rotatable cylindrical member, or roller bail, contacts the outer surface of the package as it is being built to hold the strand laid in the latest course in place at the package edges as the strand guide changes direction. The roller bail is mounted for rotation, and bearings are used to reduce the friction between the roller bail and the mounting surface. The collet and package are rotating at high speeds during winding. The contact between the roller bail and the rotating package surface causes the roller bail to rotate, and the speed of the roller bail surface is generally equal to the high rotational speed of the package surface. The roller bail has a fixed diameter which is generally less than the diameter of the collet, and may be only 10% of the collet diameter. Therefore, the roller bail must rotate at higher revolutions per minute (RPMs) to keep the roller bail surface traveling at the same speed as the speed of the package surface. To operate effectively throughout the preferred range of package sizes and preferred collet speeds during winding the roller bail may have to rotate at 70,000 RPMs or higher. Several attempts have been made to provide a method of automatically starting the winding of the strand. For example, U.S. Patent No. 3,408,012 to Smith appears to disclose a strand control member that both rotates toward the collet and shifts axially to move the strand out of engagement with the strand traverse during changeover to a new package. The transfer of the strand from the full collet to the empty collet is effected in part by the indexing of the collets to the new position. This occurs after the control member has rotated toward the collet.

U.S. Patent No. 4,040,572 to Melan et al. appears to disclose a strand deflector on a strand deflector bar. The strand reflector bar is used to guide the strand into engagement with the endcap or starting drum. When the collet starts to rotate, the strand becomes engaged without any lateral movement of the collet, the strand guide or the pull rolls. Subsequently, rotation of the strand deflector bar causes the strand deflector to remove the strand from the strand guide or fmger to allow the packing to begin.

Several attempts have also been made to provide a method for continuous winding of a strand on a tube. U.S. Patent No. 4,050,646 to Burchette appears to disclose a yarn tube with specific yarn receiving areas at the end of the tube. These yarn receiving areas are in the shape of a slot formed by cutting across an arc at the end of the tube. A plurality of such yarn receiving slots can be spaced circumferentially at the edge of the tube. Sloped or tapered sidewalls for the slots are disclosed. Although holes in the tube are disclosed (column 2, line 58), there is no suggestion for there to be holes in the tube that are aligned with strand capturing structures in the underlying collet. Further, there is no disclosure of a strand capturing slot positioned anywhere else but on the end cap.

U.S. Patent No. 4,828,200 to Adams et al . appears to disclose a yarn tube with yarn catching means at the end of the tube. However, it is desirable to provide a method for automatically starting the winding process by moving one or more collets with respect to the strand positioner and pull rolls. It is also desirable to bury or hide the strand of glass inside the strand package during startup so that the tail will not be hanging visibly outside the completed package.

SUMMARY OF THE INVENTION

The above objects as well as other objects not specifically enumerated are achieved by a method of winding a fibrous strand, the method including mounting a first collet and a second collet on a rotatable turret, and rotating the first collet to wind the strand using a cam to build a first package. The stand is transferred from the first collet to the second collet to build a second package on the second collet, and the turret is rotated while transferring the strand from the first collet to the second collet.

According to this invention, there is also provided a method of winding a fibrous strand, the method comprising mounting a first collet and a second collet on a rotatable turret, wherein each of the first and second collets has a strand capture device. A package core is mounted on each of the first and second collets. Each package core has an opening to allow the strand to have access to the strand capture device on the collet. The first collet is rotated to wind the strand to build a first package. The strand is then transferred from the first collet to the second collet to build a second package on the second collet. The transfer of the strand to the second collet includes directing the strand through the opening in the package core and into contact with the strand capture device. According to this invention, there is also provided a method of winding a fibrous strand including mounting a first collet and a second collet on a rotatable turret, and feeding the strand through a pair of pull rolls positioned below the turret. The strand is engaged with a strand positioner, and the first collet is rotated. The strand is transferred into engagement with the first collet by rotating the turret to move the first collet toward the strand. The strand is also transferred into engagement with the first collet by pivoting the strand positioner to move the strand toward the first collet. The strand is also transferred into engagement with the first collet by moving the pull rolls toward the turret to move the stand toward the first collet.

According to this invention, there is also provided apparatus for winding a fibrous strand, including a first collet and a second collet mounted on a rotatable turret. At least one strand capture device is mounted on the second collet. A package core is placed on the second collet. The package core has an opening to allow the strand to have access to the strand capture device. A strand positioner is positioned for removing the strand from the first collet and directing the strand into engagement with the strand capture device on the second collet.

Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic view in elevation of an apparatus for forming, collecting and winding fiber strands according to the principles of the invention.

Fig. 2 is an enlarged, plan view of the strand reciprocator shown in Fig. 1. Fig. 3 is a schematic sectional view in elevation of the apparatus of Fig. 2, taken along line 3-3.

Fig. 4 is an end view in elevation of a portion of the roller bail assembly of Fig. 2, taken along line 4-4.

Fig. 5 is an end view in elevation of a portion of a pair of collets mounted on a rotatable turret, a cam, a strand positioner and a pair of pull rolls.

Fig. 6 is a top view of one of the collets with a strand capture device Fig. 7 is an elevational view of the collet of Fig. 6.

Fig. 8 is a close up cross-sectional view of the strand capture device of Fig. 7. Figs. 9A-9F are schematic views in elevation of a method of automatically restarting and transferring the strand from one collet to another collet according to the method of the invention.

Fig. 10 is a side view of the collet after a few revolutions in which the strand forms a band around the collet.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION

Figs. 1 and 2 show an apparatus for forming, collecting, and winding strands in which fibers 10 are drawn from a plurality of orifices 11 in a bushing 12 and gathered into a strand 14 by means of a gathering member 16. A size suitable for coating the fibers can be applied to the fibers by any suitable means, such as size applicator 18. The strand 14 is wound around a rotating collet 22 to build a cylindrical package 19. The package 19, formed from a single, long strand, has a radially outer surface 20 with edge portions 20a and a central portion 20b between them. The edge portions 20a form generally right angles with the package ends 20c. The outer surface of the cylindrical package 19 is preferably between about 10 cm to about 40 cm long, but may be longer or shorter depending on the application. The collet 22 is adapted to be rotated about an axis of rotation 23 by any suitable means such as a motor 24. Any suitable package core material such as a cardboard tube 26 can be disposed on the collet 22 to receive the strand package 19.

A strand reciprocator 30 guides the strand 14 laterally back and forth across the package surface 20 to lay the strand in courses 44 on the package surface. The strand reciprocator 30 includes a cylindrical cam 32 having a helical groove 34. The cam 32 is adapted for rotation about an axis 33 by any suitable means such as a motor 35. The cam 32 is preferably made of a hard material, such as stainless steel, but any suitable material can be used. The strand reciprocator 30 further includes a cam follower 36 disposed in the groove 34. The cam follower 36 extends outwardly from the cam 32 and a strand guide 38 is attached to the end. The cam follower 36 is preferably made of a plastic or nylon material, but any suitable material can be used. A notch 40 is formed in the strand guide 38 to hold the strand 14. Rotation of the cam 32 causes the cam follower 36 to follow the helical groove, thereby causing the strand guide 38 to move laterally across the package surface. Referring now to Figs. 2 and 3, the strand reciprocator further includes a roller bail assembly 42 for holding the strand courses 44 in place at the edge portions 20a of the package surface 20 as the strand guide 38 changes direction. The roller bail assembly includes a pair of spaced apart, or split rollers 46. The rollers 46 have generally cylindrical edge ends 46a and tapered inner ends 46b. The cylindrical edge ends contact the package surface at the edges 20a. The tapered inner ends extend from the edge ends towards the central portion of the package surface 20b. The rollers 46 do not contact the surface of the package at the central portion of the package 20b. Each of the rollers 46 is independently mounted by mounts 48. One or more bearings (not shown) are located between the roller bails and the mounts to allow the roller bails to rotate freely by reducing friction. The bearings are preferably open, ball bearing type bearings. Although the roller bails are shown as mounted at both the edge ends and the inner ends, the roller bails may be cantilevered, being mounted at only one end. Each roller is made from a hard material, such as stainless steel, but any suitable material may be used. The rollers preferably weigh approximately 50 grams each, but may be heavier or lighter depending on their size and the application. They are preferably hollow to minimize weight and inertia, but may be solid. Each roller is preferably about 2 cm long, but they may be longer or shorter depending on the application. The split roller bails are preferably coaxial, contacting the package surface along a portion of a line 52 which is generally parallel to the package axis of rotation 23, although, any suitable orientation of the roller bails may be used. Using 2 cm long roller bails, the length of contact between the roller bails and the typical package surface will be approximately 10% to 50% of the length of the outer surface of the package. A longer or shorter length of contact between the roller bails and the package surface may be used depending on the application.

During package buildup, the strand reciprocator 30 guides the strand 14 as it is laid on the outer surface of the package. The strand is held by notch 40 in the strand guide 38 and wound around the rotating collet 22 or a package core 26 disposed about the collet. The cam 32 is oriented near the package and rotates about the axis 33 generally parallel to the package axis of rotation 23. The cam follower is disposed within the cam groove 34, but is prevented from rotating with the cam. As the cam rotates, the cam follower is moved laterally by the helical groove in a direction generally parallel to the package axis of rotation 23. The helical groove is continuous, having curved ends 34a that cause the cam follower to move to the end of the package and then reverse direction. The strand guide is attached to the cam follower and it traverses the outer surface of the package, reciprocating back and forth from end to end. The strand guide does not contact the surface of the package. The helical winding pattern of each strand course 44 is formed by reciprocating the strand across the package surface while rotating the package. As the strand guide approaches the edge portions 20a of the package, the strand is laid on the package surface under the roller tapered inner ends 46b. The strand guide continues to move towards the package ends 20c and the strand course, shown in phantom at 44a in Fig. 2, moves between the package surface and the cylindrical edge end 46a of the roller which is in contact with the package surface. When the cam follower travels through the curved end 34a of the groove 34, the strand guide 38 changes direction and moves away from the package end 20c and towards the central portion of the package 20b. The contact between the roller bails and the package surface holds the strand course 44a in place at the edge of the package surface 20a, when the strand guide 38 changes direction. By preventing the strand courses 44a from pulling away from the package edges 20c as the strand guide 38 moves back towards the center of the package 20b, a cylindrical package having square ends 20c is built. It will be appreciated that it is not necessary for the roller bails to contact the package surface for building a cylindrical package having square edges 20c. A preferred method of forming the cylindrical package is to have the strand guide 38 contacting the package surface.

The package rotates during winding as shown by line 53 in Fig. 4. As the package builds, the radius 54 increases. To accommodate the increasing package radius, the strand reciprocator 30 is mounted on an arm 56. To accommodate the increasing package radius, the arm moves away from the collet along line 63 to keep the proper contact between the surface of the rollers and the package surface, and to prevent the strand courses 44 from pulling away from the edge portions 20a of the package surface. Referring now to Fig. 5, the apparatus of the invention includes a turret 64 for housing a two or more collets 22a, 22b. It will be appreciated that the invention is not limited by the number of collets and the invention can be practiced with any desirable number of collets. A drive system 66, such as a servo motor, is operatively coupled to the turret 64 for bi-directional rotation of the turret 64, as indicated by arrow 68. It will be appreciated that the drive system 66 can be operatively coupled to a controller (not shown) for precisely controlling the indexing of the turret 64 and the position of the collets 22a, 22b. A strand positioner 70 may be provided to facilitate the positioning of the strand 14 on each collet 22a, 22b. The strand positioner 70 is capable of lateral movement, that is, toward or away from each collet 22a, 22b, as well as pivotal movement with respect to each collet 22a, 22b. In this manner, the strand positioner 70 can be precisely positioned at any desired position with respect to the collets 22a, 22b. The apparatus also includes a pair of pull rolls, shown generally at 72, positioned below the level (that is downstream) of the turret 64 and the collets 22a, 22b. The pull rolls 72 are capable of moving toward and away from the turret 64 and the collets 22a, 22b, that is, to the left and right as viewed in Fig. 5. The purpose of the pull rolls 72 will be described below.

Referring now to Figs. 6-8, the apparatus of the invention also includes one or more strand capture devices or partial grooves, shown generally at 74, built into each collet 22a, 22b for on-tube-transfer of the strand 14 from one collet to the other collet. The strand capture device 74 is built into the collet in order to hide or conceal the beginning band of the strand 14 under the remainder of the package 20. The strand capture device 74 is provided with a pin 76 and a slanted or beveled edge 78 to help capture the strand 14 when the strand 14 is laid into the strand capture device 74. It will be appreciated that other strand capture methods can be used within the partial grooves. Preferably, the strand capture device 74 is positioned axially between the ends or edges of the package core 26 rather than axially beyond the package core 26. The strand capture device 74 does not extend all the way around the circumference of the collet, but rather extends only around a portion of the circumference of the collet, such as, for example, only a few inches around the circumference of the collet. In a particular embodiment of the invention, the strand capture device 74 extends around an arc of about 20 to 40 degrees of the 360 degrees of the entire collet circumference. Although the invention can be practiced with one strand capture device 74, it has been found that each collet 22a, 22b can include one or more strand capture devices 74. When the cardboard tube or package core 26 is placed on the collet, an opening or cutout (not shown) in the package core 26 is required in order to expose the strand capture device 74 to the strand 14. The opening does not extend circumferentially all the way around the core 26, and therefore, when the core 26 is placed on the collet 22a, 22b the opening must be aligned axially and circumferentially with the strand capture device so that the strand can extend through the core 26 and reach the strand capture device 74.

Referring now to Figs. 9A-9F, the preferred method of automatically restarting and tube-to-tube transfer of the strand in accordance with the method of the invention will be described. As shown in Fig. 9 A, the automatic restart aspect of the invention begins by rotating the turret 64 counterclockwise (as viewed in Fig. 9A) approximately 45 degrees from the winding position such that the two collets 22a, 22b are generally vertical with respect to each other. At the same time, the cam 30 is moved away from the turret 64 and the two collets 22a, 22b. Then, the sliver operator feeds the strand 14 into the pull rolls 72 that are positioned below (that is, downstream) the two collets 22a, 22b.

As shown in Fig. 9B, the strand positioner 70 then pivots about 45 degrees to move the strand 14 towards the collet 22a while the turret 64 rotates clockwise (as viewed in Fig. 9B) to move the collet 22a toward the strand 14. At the same time, the pull rolls 72 move toward the turret 64 and the two collets 22a, 22b to also bring the strand 14 closer to the collet 22a until the strand 14 is transferred onto the end of the tube 26 of collet 22a by using means well known in the art, such as grooves, pins, and the like. At this point, the automatic restart is complete and the package is ready to be built on the collet 22a. Next, the strand positioner 70 rotates back to disengage from the strand 14, and the cam 30 moves back into engagement with the collet to wind the strand, as shown in Fig. 9C.

When package buildup is complete, the tube-to-tube transfer aspect of the invention begins by engaging the strand 14 with the strand positioner 70 and moving the strand 14 off the package 19 and onto the end of the tube 26, as shown in Fig. 9D.

Next, the turret 64 rotates clockwise (as viewed in Fig. 9D) to begin indexing the collet 22b while the cam 30 moves away from the turret 64 and the two collets 22a, 22b, as shown in Fig. 9D. Then, the strand positioner 70 moves to align the strand 14 with the strand capture device 74 while the collet 22b is started up to running speed, as shown in Fig. 9E. At the same time, the turret 64 completes the indexing so that it rotates into the winding position, thereby moving the collet 22b toward the strand 14. Alternatively, the strand 14 can be transferred onto to the collet 22b by using the strand capture device 74, rather than first being transferred onto the end of the tube 26 and then aligned with the strand capture device 74 of the collet 22b. When the strand 14 is captured by the strand capture device 74, the strand 14 wraps around on itself to form an inner band 80 on the collet 22b and breaks off due to the tension from the pull rolls 72 and the rotating collet 22b, as shown in Fig, 10. The next package is then ready to be built on the collet 22b.

Next, the strand positioner 70 is disengaged from the strand 14 and moved out of the way, as shown in Fig. 9F. The cam 30 is advanced toward the turret 64 and the collets 22a, 22b and into place for oscillation of the strand 14 on the collet 22a. The strand guide 38 on the cam 30 intercepts the strand 14 and engages it to move the strand 14 axially along the package 19 for package buildup.

One advantage of the method of the invention is that the startup strand is buried inside the completed package so that the tail of the startup strand will not be hanging visibly outside the completed package. Another advantage of the method of the invention is that the strand is transferred from one collet to another without the need of operator assistance. Another advantage of the method of the invention is that the strand capture device is located axially within the package geometry (that is, axially between the ends of the package), so that the start up band will also be visible when the package is completed. In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.

Claims

WHAT IS CLAIMED IS:

1. A method of winding a fibrous strand, the method comprising the steps of: mounting a first collet (22a) and a second collet (22b) on a rotatable turret (64); rotating the first collet to wind the strand (14) using a cam (30) to build a first package (20); transferring the strand from the first collet to the second collet to build a second package on the second collet; and rotating the turret while transferring the strand from the first collet to the second collet.

2. The method defined in Claim 1, further including the step of moving the cam (30) away from the turret (64) prior to transferring the strand (14) from the first collet (22a) to the second collet (22b).

3. The method defined in Claim 1, wherein the strand (14) is positioned onto the second collet (22b) from the first collet (22a) by using a strand positioner (70) for engaging the strand, wherein the strand positioner pivots towards the turret (64) while positioning the strand on the second collet.

4. The method defined in Claim 3, further including the step of disengaging the strand (14) from the strand positioner (70) once the strand is transferred from the first collet (22a) to the second collet (22b).

5. The method defined in Claim 1, further including the step of moving the cam (30) toward the turret (64) after the strand (14) is transferred from the first collet (22a) to the second collet (22b).

6. The method defined in Claim 1, wherein each of the first and second collets (22a, 22b) has a strand capture device (74), and a package core (26) is mounted on each of the first and second collets, wherein each package core has an opening to allow the strand to have access to the strand capture device on the collet, and wherein the step of transferring the strand from the first collet to the second collet includes introducing the strand through the opening in the package core and into contact with the strand capture device.

7. A method of winding a fibrous strand (14), the method comprising the steps of: mounting a first collet (22a) and a second collet (22b) on a rotatable turret (64), wherein each of the first and second collets has a strand capture device (74); mounting a package core (26) on each of the first and second collets, wherein each package core has an opening to allow the strand to have access to the strand capture device on the collet; rotating the first collet to wind the strand to build a first package (20); and transferring the strand from the first collet to the second collet to build a second package on the second collet, wherein the transfer of the strand to the second collet includes directing the strand through the opening in the package core and into contact with the strand capture device.

8. The method defined in Claim 7 in which the strand capture device (74) extends only around a portion of the circumference of the collet (22).

9. A method of winding a fibrous strand (14), the method comprising the steps of: mounting a first collet (22a) and a second collet (22b) on a rotatable turret (64); feeding the strand through a pair of pull rolls (72) positioned below the turret; engaging the strand with a strand positioner (70); rotating the first collet; and transferring the strand into engagement with the first collet by rotating the turret to move the first collet toward the strand; pivoting the strand positioner to move the strand toward the first collet; and moving the pull rolls toward the turret to move the stand toward the first collet.

10. The method defined in Claim 9, further including the step of moving a cam (30) into engagement with the collet (22) after the strand (14) is transferred onto the collet.

11. An apparatus for winding a fibrous strand, comprising: a first collet (22a) and a second collet (22b) mounted on a rotatable turret (64); at least one strand capture device (74) mounted on the second collet; a package core (26) on the second collet, the package core having an opening to allow the strand to have access to the strand capture device; and a strand positioner (70) for removing the strand from the first collet and directing the strand into engagement with the strand capture device on the second collet.

12. The apparatus according to claim 11, wherein the package core (26) has ends, and the package core is positioned on the collet (22) so that the strand capture device (74) is positioned axially between the ends of the package core.

13. The apparatus according to Claim 11, wherein the strand capture device (74) extends only around a portion of the circumference of the collet (22).

14. The apparatus according to Claim 13, wherein the strand capture device (74) extends around an arc of about 20 to 40 degrees of the 360 degrees of the entire collet (22) circumference.