Apparatus and method for winding threads onto a former

Abstract

An apparatus for winding a plurality of threads onto a former, wherein the apparatus has at least one ring traverse that at least partly surrounds the former. Via the ring traverse, threads are fed to the former from a plurality of different feed directions. With each feed direction there is associated at least one transfer element, from which the at least one thread is taken up on the former. The distance to the former axis is adjustable at least for some of the transfer elements.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for winding a plurality of threads onto a former. The invention further relates to a method for winding the threads onto the former. The threads may include at least one fiber and/or two or more fibers which are fed and wound together.

2. Description of the Related Art

From practical experience it is already known how to wind fibers or fiber strands onto a former. The threads or fiber strands can be impregnated beforehand with a resin, after which the impregnated fiber strand is wound onto the former. The former is in particular a cylindrical hollow body, such as a blow-molded plastic container. The resulting end product can be used, for example, as a tank for liquids or gases or similar substances. In principle, it is also known from practical experience how to feed at least one fiber to a former from each of a plurality of different feed directions. This feed of fibers from different directions is accomplished by what is known as a ring traverse. The ring traverse is provided with a plurality of transfer elements distributed around the former. During operation of the apparatus, at least one thread is taken up on the former from a transfer element. In the process, the thread can be brought up to the former tangentially, for example. The apparatuses known from practical experience have the disadvantage that the working technique that can be achieved therewith is poorly flexible and poorly variable.

SUMMARY OF THE INVENTION

In contrast, the technical problem underlying the invention is to provide an apparatus of the type mentioned hereinabove, with which a very flexible and variable working technique with high functional reliability and high precision in applying the starting turns is possible. A further technical problem underlying the invention is to provide a corresponding method.

To solve the technical problem, the invention includes an apparatus for winding a plurality of threads onto a former,

• • wherein there is provided at least one ring traverse, which surrounds the former at least partly, with which ring traverse at least one thread can be fed to the former from each of a plurality of different feed directions,
  • wherein at least one transfer element from which the at least one thread is taken up on the former is associated with each feed direction
  • and wherein the distance to the former axis or to the former can be adjusted at least for some of the transfer elements.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail hereinafter on the basis of a drawing, which illustrates merely one practical example that is not intended to limit the claimed invention and in which, in schematic diagrams:

FIG. 1 shows a perspective view of an inventive apparatus,

FIG. 2 shows a top view of an inventive ring traverse in a first embodiment,

FIG. 3 shows the object according to FIG. 2 in a second embodiment,

FIG. 4 shows the object according to FIG. 2 in a third embodiment,

FIG. 5 shows the object according to FIG. 2 in a fourth embodiment,

FIG. 6 shows the object according to FIG. 2 in a fifth embodiment,

FIG. 7 shows an inventive ring traverse in a sixth embodiment, and

FIG. 8 shows a schematic diagram of an inventive distance adjustment means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The term thread in the context of the invention means in particular at least one fiber or two or more fibers. The at least one fiber, preferably two or more fibers, is taken up on the former from a transfer element. The fibers can be, for example, glass fibers, carbon fibers, aramide fibers or even plastic fibers.

In one embodiment, the former can be what is known as a liner, or in other words a former that remains in the product and becomes a part of the product. In other embodiments, the former can be a mandrel, which is withdrawn from the product after a winding operation, and which is available once again for further winding operations. It is within the scope of the invention for a former to be driven in rotation during a winding operation.

The ring traverse is expediently provided with an opening for the former. This means that the former axis passes through a central opening of the ring traverse. At least one thread or at least one fiber, preferably two or more fibers, is fed from each of several feed directions with the ring traverse. For example, there can be eight feed directions, and one or more fibers can be fed from each of these feed directions. The number of feed directions may be less than eight (for example 1, 2, 3, 4, 5, 6, 7) or greater than eight if necessary. A transfer element is associated with each of these feed directions. It is at the transfer element that the fibers/threads being fed have their last contact with the ring traverse, after which they are taken up on the former. Several configurations are possible for the transfer element. In the simplest case, the transfer element can be a deflecting pin, a deflecting rod or a roll or the like. According to a preferred embodiment of the invention, a transfer element is designed as a thread guide eye. This is a ring-shaped element with preferably circular cross section. Other shapes such as open ring, square or polygonal may be used. The thread is fed to the former through the ring opening of the thread guide eye. Expediently, a thread guide eye is provided at the end of a transfer arm or transfer lever. Relative to the circumference of the former, the transfer elements are disposed around the former with a distance to the former.

It is within the scope of the invention for at least some of the transfer elements to be disposed with equal distance to the former axis. According to a particularly preferred embodiment of the invention, all transfer elements are disposed with the same distance to the former axis.

In a very preferred embodiment the distance to the former axis can be adjusted together or simultaneously or synchronously for at least some of the transfer elements. Preferably, the distance to the former axis can be adjusted together, simultaneously or synchronously with a single adjusting means (e.g., an adjuster). The approach movement of the transfer elements relative to the former expediently takes place linearly, especially radially or tangentially relative to the former. However, the approach movement of the transfer elements relative to the former can also follow an arcuate path. Preferably, the distance to the former axis can be adjusted together or simultaneously or synchronously for all transfer elements of the ring traverse. In principle, however, it is also within the scope of the invention for the distances to the former axis to be adjustable independently of one another for at least some or for all transfer elements.

According to a particularly preferred embodiment of the invention, transfer elements that are adjusted together or simultaneously or synchronously are always disposed with the same distance to the former axis. The transfer elements are expediently disposed on a circle around the former or around the former axis.

According to one embodiment of the invention, the thread guide of the transfer elements has the shape of an arc or of a ring segment. The threads or the fibers then run over a curved guide surface of the transfer element. According to another embodiment, a transfer element is designed as a thread guide eye. In this case the threads or fibers run through the opening of the thread guide eye, which has circular shape, for example.

According to one embodiment of the invention, the adjusting means and/or adjuster is designed with the criterion that the distance of the transfer elements from the former axis be adjustable in the manner of an iris aperture. As an example, the adjustment of the distances of the transfer elements can be achieved by operating with a closed-track cam plate, to be explained in more detail in the description of the figures.

According to a very preferred embodiment of the invention, a suitable motor, especially a servo motor or stepping motor, can be used for the drive of the adjusting means. However, driving or actuation of the adjusting means for adjustment of the distance of the transfer elements can also be accomplished pneumatically or servo-pneumatically or hydraulically or servo-hydraulically.

As an example, a crown gear in which toothed gears mesh or a bevel crown gear with associated bevel gears can be used for adjustment of the distances of the transfer elements together. The adjustment of the distances of the transfer elements can also be accomplished via a lever mechanism. Furthermore, a plane spiral, for example, can also be used for adjustment of the distances of the transfer elements. The use of pinions meshing with a toothed belt or with a cylindrical crown gear is also possible for bringing about adjustment of the transfer-element distances. Moreover, the adjustment of the distances of the transfer elements can also be achieved via a wedge-bar mechanism.

Also included in the invention is a method for winding a plurality of fibers onto a former, wherein at least one thread is fed to the former from each of a plurality of different feed directions by the transfer elements associated with the feed directions, and wherein the distance to the former axis is adjusted for at least some of the transfer elements. According to a particularly preferred embodiment of the inventive method, the distance is adjusted simultaneously or synchronously for at least some of the transfer elements and preferably for all transfer elements.

The invention permits a very flexible, variable and at the same time functionally reliable working technique via the inventive adjustment of the distances of the transfer elements. In particular, shorter movement paths can be achieved during winding. Because of the flexible adjustment of the distances, a high working speed and thus a high productivity can always be achieved. Nevertheless, threads can be laid down more precisely than is possible in the arrangements known from the prior art. The products produced with the inventive method are therefore distinguished by flawless quality. It can be further emphasized that the inventive apparatus is of less expensive and less complex construction and therefore can also be made easily.

The figures relate to an apparatus for winding fibers 1 onto a former 2. In the practical example according to the figures, there is provided a ring traverse 3 that completely surrounds former 2. In other words, former 2 or its former axis F passes through an opening 4 of ring traverse 3. Via ring traverse 3, fibers 1 can be fed to former 2 from a plurality of different feed directions. Expediently two or more fibers 1 can be fed from one feed direction. Associated with each feed direction is a transfer element 5, from which fibers 1 are taken up on former 2. In other words, the last contact of fibers 1 with ring traverse 3 takes place at transfer element 5, before fibers 1 are taken up on former 2. According to the invention, the distance a to former 2 or to former axis F can be adjusted at least for some, preferably for all transfer elements 5. FIGS. 2 to 7 show several adjustment options or several adjustment means for this purpose. Preferably, the distance a of all transfer elements 5 to former axis F is adjusted together or synchronously. In principle, however, the distances of the individual transfer elements 5 to former axis F could also be adjusted independently of one another. Hereinabove and hereinafter, distance a of a transfer element 5 means in particular the distance a from former axis F of the last point of contact of a fiber 1 on transfer element 5.

FIG. 2 illustrates a ring traverse 3 with three transfer elements 5. In this case, therefore, fibers 1 are fed to former 2 from three feed directions. Transfer elements 5 in this case are designed as thread guide eyes 15, which are attached to transfer arms 16 functioning as lever elements. Each of these transfer arms 16 can be swiveled around a swivel shaft 6. Otherwise, each transfer arm 16 is provided with an oblong hole 7, in which a pin 8 fixed to a drive ring 9 engages. During rotation of drive ring 9, transfer arms 16 are swiveled in the direction of the two-headed arrows and in this way the distance a of thread guide eyes 15 to former axis F is varied. In this embodiment, distance a is adjusted simultaneously or synchronously for all transfer elements 5 or thread guide eyes 15 and all transfer elements 5 always have the same distance a to former axis F.

The embodiment according to FIG. 3 operates with a bevel gear mechanism for adjustment of distance a. In this case, a bevel gear 10 meshing with a bevel crown gear 11 is associated with each transfer element 5. During rotation of bevel crown gear 11, bevel gear 10 also rotates, as does the spindle 12 or screw attached to it. A nut 13 seated on the male thread of spindle 12 is displaced on spindle 12 when bevel gear 10 and spindle 12 rotate. Thereby the distance of transfer element 5 from former axis F is varied. In this case also, transfer elements 5 are designed as thread guide eyes 15, each of which is attached to a nut 13. In this embodiment also, the distances a are varied simultaneously or synchronously for all transfer elements 5 and all transfer elements 5 always have the same distance a to former axis F.

The embodiment according to FIG. 4 also operates with a bevel gear mechanism. In this case also, a bevel gear 10 meshing with a bevel crown gear 11 is associated with each transfer element 5. During rotation of bevel crown gear 11, each bevel gear 10 also rotates, and thereby an adjusting screw 14 engaging in bevel gear 10 is displaced. For this purpose, the male thread of each adjusting screw 14 cooperates with a female thread of associated bevel gear 10. To each adjusting screw 14 there is attached a transfer element 5 designed as a thread guide eye 15. In this case also, fibers 1 are fed to former 2 through the openings of thread guide eyes 15. In this embodiment, the distances a of transfer elements 5 or thread guide eyes 15 are adjusted simultaneously or synchronously and all transfer elements 5 or thread guide eyes 15 always have the same distance a to former axis F.

In FIG. 5 also, transfer elements 5 are designed as thread guide eyes 15, each of which is attached to a transfer arm 16. During rotation of a pinion 17 having eccentric disk 24, a cam acts on transfer arm 16, in such a way that this can be displaced in the direction of the two-headed arrow. Pinions 17 are expediently driven via a circulating traction mechanism, for example via a toothed belt 18 or via a chain. In the practical example according to FIG. 5, toothed belt 18 is also guided over deflecting pulleys, of which one deflecting pulley 19 expediently drives toothed belt 18 at any given time.

FIG. 6 shows an embodiment similar to that of FIG. 5. In this case, however, pinions 17 mesh with a cylindrical crown gear 20. During rotation of cylindrical crown gear 20, therefore, transfer arms 16 together with their attached thread guide eyes 15 are moved in the direction of the two-headed arrow. In the embodiments according to FIGS. 5 and 6 also, distance a of transfer elements 5 or of thread guide eyes 15 to former axis F is adjusted simultaneously or synchronously and all transfer elements 5 or thread guide eyes 15 always have the same distance a to former axis F in any given adjusted functional position.

The embodiment according to FIG. 7 operates with a closed-track cam plate 21. To each transfer element 5 designed as a thread guide eye 15 there is attached a transfer arm 16, on which there is disposed an engagement element 22, such as an appropriate pin. Engagement element 22 engages in an arcuate or curved elongated hole 23. During rotation of closed-track cam plate 21, transfer arms 16 are displaced in this way in the direction of the two-headed arrow and in this way distance a of thread guide eyes 15 to former axis F is varied simultaneously or synchronously.

A method for adjustment of distance a in a manner analogous to that of the embodiment according to FIG. 7 is indicated very schematically in FIG. 8. In the embodiment according to FIG. 8, distance a of transfer elements 5 is varied or adjusted in the manner of an iris aperture.

It remains to be mentioned that former 2 or the mandrel can be removed axially through ring traverse 3 after the end of the winding process. According to another embodiment, however, former 2 can also be removed radially through corresponding openings in ring traverse 3.

European application 04005981.8, filed on Mar. 12, 2004 is incorporated herein by reference in its entirety.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

1. An apparatus for winding a plurality of threads or fibers onto a former, comprising:

at least one ring traverse which may at least partly surround the former, wherein the ring traverse is configured so that at least one thread can be fed to the former from each of a plurality of different feed directions, and

at least one transfer element adjustably connected to ring traverse, wherein at least one transfer element is associated with each feed direction and is configured to guide at least one thread onto the former,

wherein the distance between one or more of the transfer elements and the longitudinal axis of the former is adjustable.

2. The apparatus according to claim 1, wherein two or more of the transfer elements are of equal distance to the axis of the former.

3. The apparatus according to claim 1, further comprising an adjusting means connecting one or more of the transfer elements and the ring traverse, wherein the adjusting means is configured to adjust the distance between the one or more the transfer elements and the axis of the former and the one or more the transfer elements are adjusted together.

4. The apparatus according to claim 3, wherein the adjusting means is a closed-track cam plate.

5. The apparatus according to claim 3, wherein the adjusting means is a servo or stepping motor.

6. The apparatus according to claim 3, wherein the one or more transfer elements configured to adjust together are always disposed with the same distance to the former axis.

7. The apparatus according to claim 1, wherein at least one of the transfer elements has a thread guide having the shape of an arc or of a ring segment.

8. The apparatus according to claim 1, wherein a transfer element is configurable as a thread guide eye.

9. The apparatus according to claim 1, wherein the distance between the transfer elements and the axis of the former is adjustable with an iris aperture present in the adjusting means.

10. A method for winding a plurality of fibers onto a former, comprising:

feeding at least one thread to the former from each of a plurality of different feed directions with one or more transfer elements associated with each of the feed directions, and

adjusting the distance between the transfer elements and the axis of the former for at least some of the transfer elements.

11. The method according to claim 10, wherein the distance is adjusted simultaneously or synchronously for at least some of the transfer elements.