DE102012012974B4 - Elastic rotary connecting element, in particular elastic torsion coupling or elastic flexible disk, and method for its production - Google Patents

Abstract

Elastic rotary connection element with a) at least two fastening elements which have a tubular bushing; b) on each bushing at least one collar sleeve, each of which has an axially extending region and a radially projecting collar at both ends of this region; c) at least one oval-shaped collar made of one Thread-wound thread package, which in turn comprises two mutually parallel runs and two opposite arcuate deflection areas; whereind) the thread package is guided into the deflection area between the collars of a collar sleeve around its axially extending area; characterized in thate) the axially extending regions of the collar sleeves are shortened in the axial direction compared to an initial state by applying a force which compresses the thread package (6, 7, 8) between the collars of the collar sleeves.

Description

• a) mindestens zwei Befestigungselementen, die eine rohrförmige Buchse aufweisen;
• b) auf jeder Buchse mindestens einer Kragenhülse, die jeweils einen axial verlaufenden Bereich und an beiden Enden dieses Bereichs jeweils einen radial überstehenden Kragen aufweist;
• c) mindestens einem oval geformten, aus einem Faden gewickelten Fadenpaket, das seinerseits zwei zumindest etwa parallel verlaufende Trums und zwei gegenüberliegende bogenförmige Umlenkbereiche umfasst; wobei
• d) das Fadenpaket in den Umlenkbereichen jeweils zwischen den Kragen einer Kragenhülse um deren axial verlaufenden Bereich geführt ist; sowie ein Verfahren zur Herstellung eines elastischen Drehverbindungselements, insbesondere einer elastischen Torsionskupplung oder einer elastischen Gelenkscheibe, bei welchem
• a) mindestens ein Fadenpaket um zwei Kragenhülsen gelegt wird, die jeweils einen axial verlaufenden Bereich und an beiden Enden dieses Bereichs jeweils einen radial verlaufenden Kragen aufweisen;
• b) die aus den beiden Kragenhülsen und dem Fadenpaket gebildete Baugruppe an zwei Befestigungselemente bildenden rohrförmigen Buchsen, die mit parallelen Achsen in Abstand zueinander angeordnete sind, durch Aufschieben der Kragenhülsen montiert wird;
• c) die Buchse, die Kragenhülsen und das Fadenpaket zur Ausbildung eines elastomeren Körpers mit einem entsprechenden Material umgossen werden.

The invention relates to an elastic rotary connecting element, in particular an elastic torsion coupling or elastic joint disk

• a) at least two fastening elements which have a tubular bushing;
• b) on each bushing at least one collar sleeve, each of which has an axially extending region and a radially projecting collar at both ends of this region;
• c) at least one oval-shaped thread package wound from a thread, which in turn comprises two at least approximately parallel strands and two opposite arcuate deflection areas; where
• d) the thread package is guided in the deflection areas between the collars of a collar sleeve around its axially extending area; and a method for producing an elastic rotary connection element, in particular an elastic torsion coupling or an elastic joint disk, in which
• a) at least one thread package is placed around two collar sleeves, each of which has an axially extending region and a radially extending collar at both ends of this region;
• b) the assembly formed from the two collar sleeves and the thread package is mounted on two tubular bushings forming fastening elements, which are arranged at a distance from one another with parallel axes, by pushing on the collar sleeves;
• c) the bushing, the collar sleeves and the thread package are cast with an appropriate material to form an elastomeric body.

Non-switchable elastic rotary connecting elements are installed for the purpose of torque-transmitting connection between two shaft connections. For safe torque transmission, they have thread packages embedded in an elastomeric body, each of which connects two fastening elements that serve as screwing points. In addition to torque transmission, the purpose of these rotary connecting elements is to isolate vibrations and acoustically decouple the two shafts from each other.

Rotary connection elements can be composed of a plurality of individual tabs, each of which has its own elastomeric body. These tabs connect two fasteners together. In this case, a torsion coupling is often referred to.

In another design, a plurality of fastening elements and thread packages connecting them to one another are embedded overall in an elastic body. This is often referred to as an elastic joint disc.

• Bei der Bau- und Verfahrensweise, die beispielsweise in der DE 37 34 089 A1 beschrieben ist, wird das Fadenpaket im Allgemeinen in die Freiräume der bereits auf den rohrförmigen Buchsen befestigten Kragenhülsen eingewickelt. Die Kragenhülsen sind dabei in sich starre Gebilde. Der Vorteil dieser Art von Wickelprozess ist, dass das Wickeln bereits auf demjenigen Bauteil geschieht, welches in das Endprodukt Eingang findet. Dies bedeutet, dass sich der Umschlingungsdurchmesser bzw. die resultierende Fadenlänge während des Fertigungsprozesses nicht mehr ändert. Da bei einem so durchgeführten Wickelprozess von Fadenlage zu Fadenlage im Endprodukt keine Fadenlängendifferenzen entstehen, resultiert eine homogene, gleichmäßige Querschnittsbelastung des Fadenpakets in Betrieb. Außerdem wird verhindert, dass das Fadenpaket aufgrund der Elastizität des Fadens in axialer Richtung aufgehen kann. Auch eine axiale Aufweitung der Fadenpakete unter Last wird vermieden. Ein weiterer Vorteil ist, dass bei diesem Verfahren zum Wickeln der Fadenpakete nicht gummierte oder mit sonstigem klebrigem Überzug versehen Fäden verwendet werden können, da das Fadenpaket in ein geometrisch fest vorgegebenes System gewickelt wird.

The manner in which the various thread packages installed in them were wound and mounted on the bushings of the fastening elements is of great importance for the performance of such elastic rotary connecting elements. Two different procedures are described in the prior art, both of which have their specific advantages and disadvantages:

• In the construction and procedure, for example in the DE 37 34 089 A1 is described, the thread package is generally wrapped in the free spaces of the collar sleeves already attached to the tubular bushings. The collar sleeves are inherently rigid structures. The advantage of this type of winding process is that the winding takes place on the component that will be used in the end product. This means that the wrap diameter or the resulting thread length no longer changes during the manufacturing process. Since a winding process carried out in this way does not produce thread length differences from thread layer to thread layer in the end product, the result is a homogeneous, uniform cross-sectional load on the thread package during operation. It also prevents the thread package from unraveling in the axial direction due to the elasticity of the thread. An axial expansion of the thread packages under load is also avoided. Another advantage is that with this method for winding the thread packages, threads that are not rubberized or have any other sticky coating can be used, since the thread package is wound in a geometrically fixed system.

The disadvantage of this type of winding, however, is that in order to achieve a high specific force transmission cross section, as many threads as possible must be wound into the specified free space of the collar sleeves. This can only be achieved with a high thread tension. Similar to tensile rubber parts, the threads used have an initially degressive and progressive characteristic, i.e. deformation depending on the acting force. This degressive identifier as well as the lower part of the progressive identifier is used when winding with high thread tension destroyed. This affects the lower characteristic curve range of the finished rotary connection element, which should be as soft as possible. The desired decoupling of structure-borne noise between the two shafts connected to one another by the rotary connecting element is not possible or only possible to a limited extent in this way.

In another type of production of the elastic rotary connecting elements, such as those in DE 10 2008 047 596 A1 As described, the thread packages are wound separately before being applied to the socket and then mounted on the sockets. The disadvantage of this method is that the thread packages must first be wound on larger bolt diameters than the final diameters of the bushings or collar sleeves on which the thread packages ultimately have to be attached. Each process step between winding and final assembly on the bushings or collar sleeves must be accompanied by a gradation of the corresponding tool diameter, otherwise trouble-free, reliable production cannot be guaranteed. The result is a change in thread length from thread layer to thread layer. This leads to an inhomogeneous contact pattern of the entire thread package. In order to be able to handle the thread packages, the individual threads in the package must be glued together, which is usually achieved by applying a rubber solution to the thread before winding.

The specific force transmission cross section is lower in this second manufacturing process than in the first one described above. The maximum possible thread package height is determined by the axial length of the bushings or collar sleeves and the elasticity of the threads. The manufacturing process uses an “open” thread package. This must never protrude beyond the part on which it is located in order to avoid thread layers being sheared off during the assembly process. Therefore, only minimal compression (approx. 10%) of the thread packages is possible. With “open” thread packages, axial expansion of the thread packages is possible under load. The couplings manufactured in this way meet the acoustic and vibration requirements placed on them. However, the number of load cycles and the service life are far below those achieved using the first manufacturing process described above.

The object of the present invention is to create an elastic rotary connecting element of the type mentioned at the outset and a method for producing it, in which the described disadvantages of both manufacturing methods are largely avoided.

• e) die axial verlaufenden Bereiche der Kragenhülsen in axialer Richtung gegenüber einem Ausgangszustand durch Aufbringen einer Kraft verkürzt sind, welche das Fadenpaket zwischen den Kragen der Kragenhülsen komprimiert.

This task is solved by the elastic rotary connecting element

• e) the axially extending regions of the collar sleeves are shortened in the axial direction compared to an initial state by applying a force which compresses the thread package between the collars of the collar sleeves.

In the method according to the invention, similar to the second manufacturing method described above according to the prior art, the winding process is carried out separately, in a separate device. The wrapping takes place on those collar sleeves that are later to be installed in the finished product. The collar sleeves are wound in a state in which the two collars are at a relatively large distance from one another; the winding process can be carried out with a low thread tension, so that the disadvantageous consequences of the high thread tension, which are present in the first manufacturing method according to the prior art, do not occur. In order to be able to achieve the high thread density of the thread package, the collar sleeves are shortened in the axial direction after the thread package has been wound up. This is done by applying an axial force. The collars of the collar sleeves approach each other, whereby the thread package lying between them is compressed and thereby compacted.

By winding the thread on the “final” components, i.e. the collar sleeves that will later be found in the elastic rotary connecting element, thread length errors as the thread layer increases are avoided and a uniform contact pattern is achieved across the thread package cross section. The compressed state of the thread package is “frozen” by appropriately fixing the second, smaller distance between the two collars of the collar sleeves from one another. In a rotary connection element according to the invention, the thread package can be compressed by up to 50%; The compression height can be set continuously up to this value. With the rotary connection element according to the invention, the number of load cycles or service life values of the manufacturing method described first are achieved according to the state of the art, but without making any compromises with regard to the acoustic and vibration requirements. The thread packages can be processed easily and cost-effectively in the assembly process. A rubber coating on the thread is not absolutely necessary.

In a preferred embodiment of the invention, at least one collar sleeve is composed of two collar parts, each of which is provided with a collar, the axially extending area of at least one collar part comprises a plurality of spaced apart strips which are connected at one end to the respective collar and are passed through slots in the other collar part at the opposite ends and are fixed to this.

It is particularly preferred if both collar parts have stripes, the strips of one collar part and the strips of the other collar part interlocking like a comb. In this embodiment of the invention, in the compressed state, a closed winding surface is formed in the axially extending region of the collar sleeves, which prevents thread wear.

The collar sleeve can be made of deep-drawn metal or an injection-molded material, in particular plastic.

• d) das Aufwickeln des Fadenpakets auf die Kragenhülsen im Schritt a in einem Zustand geschieht, in welchem der axial verlaufende Bereich der Kragenhülsen eine erste Länge besitzt;
• e) durch Aufbringen einer axialen Kraft unter Kompression des Fadenpaketes zwischen den Kragen die axial verlaufende Bereiche der Kragenhülsen auf eine zweite, kleinere Länge verkürzt wird; wonach die Schritte b und c ausgeführt werden.

As far as the process is concerned, the above-mentioned task is solved in that:

• d) the winding of the thread package onto the collar sleeves in step a occurs in a state in which the axially extending region of the collar sleeves has a first length;
• e) by applying an axial force while compressing the thread package between the collars, the axially extending regions of the collar sleeves are shortened to a second, smaller length; after which steps b and c are carried out.

The advantages of this method result analogously from the advantages of the elastic rotary connecting element according to the invention described above.

• f) der Faden zunächst auf einen kreiszylindrischen Vorsprung eines Wickelkörpers zu einem Zwischenprodukt in Form eines Kreisringzylinders gewickelt wird;
• g) das Zwischenprodukt von dem Wickelkörper abgenommen wird;
• h) in das Innere des Zwischenprodukts zwei Kragenhülsen in ihrem Ausgangszustand mit größerer Länge eingeführt werden;
• i) die Kragenhülsen und das Zwischenprodukt unter Aufbringen einer Kraft komprimiert werden, sodass die Kragenhülsen in axialer Richtung ihre verkürzte Abmessung erhalten;
• k) die Kragenhülsen vor oder nach dem Schritt i auseinander bewegt werden, sodass das Fadenpaket eine ovale Form erhält.

A particularly advantageous type of method according to the invention is characterized in that:

• f) the thread is first wound onto a circular cylindrical projection of a winding body to form an intermediate product in the form of a circular ring cylinder;
• g) the intermediate product is removed from the winding body;
• h) two collar sleeves in their initial state with a greater length are inserted into the interior of the intermediate product;
• i) the collar sleeves and the intermediate product are compressed by applying a force so that the collar sleeves obtain their shortened dimension in the axial direction;
• k) the collar sleeves are moved apart before or after step i so that the thread package has an oval shape.

The advantage of this approach is that the thread tension remains constant when winding the thread package. From thread layer to thread layer, the thread tension can be maintained exactly in the intermediate product initially produced and then also in the final product made from it. The result is an even tension distribution in the thread package that can be easily reproduced even under series conditions.

The compression process can be controlled by both force and distance. The compression can reduce the axial dimension of the intermediate product or the thread package by up to 50%, preferably by about 30%.

• 1 perspektivisch eine elastische Gelenkscheibe;
• 2 einen Axialschnitt durch die Gelenkscheibe von 1;
• 3 bis 5: verschiedene Stadien in der Montage einer Kragenhülse, wie sie in der Gelenkscheibei der 1 und 2 zum Einsatz kommt;
• 6 bis 8: verschiedene Schritte bei einer bevorzugten Art, die Gelenkscheibe der 1 und 2 herzustellen.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawing; show it

• 1 in perspective an elastic joint disc;
• 2 an axial section through the articular disc of 1 ;
• 3 until 5 : different stages in the assembly of a collar sleeve, as in the joint disc 1 and 2 is used;
• 6 until 8th : different steps in a preferred type, the articular disc of the 1 and 2 to produce.

The ones in the 1 and 2 The elastic joint disk shown, which is marked overall with the reference number 1, serves in a known manner for the elastic connection of two shafts. For this purpose, it has six fastening elements 2, which are arranged at the corners of a regular hexagon and each include a socket 3, the axes of which run parallel to one another perpendicularly on the plane spanned by the hexagon. The bushings 3 of the fastening elements 2 protrude at the top and bottom from an elastomeric body 4, which surrounds a central opening 5 in a ring-like manner.

The fastening elements 2 are connected to one another by a large number of thread packages 6, 7, 8. This is done in such a way that on three sides of the hexagon mentioned above, two adjacent fastening elements 2 are connected by a single, relatively wide thread package 6 running in the axial center of the corresponding bushings 3, while on the other three sides of the regular right ckes the adjacent fastening elements 2 are each connected by two narrower thread packages 7, 8, which run at the height of the axial end regions of the bushings 3. In this way, an arrangement is created in which two adjacent fastening elements 3 are alternately connected to one another by a central thread package 6 and two outer thread packages 7, 8.

The thread packages 6, 7, 8 are not wrapped directly around the sockets 3 of the fastening elements 2 but are wound on collar sleeves 9 on a separate device that corresponds to the state of the art and will not be explained further here, the construction of which is explained further below using the 3 until 5 is described in more detail and which are pushed over the bushings 3 and fastened to them during the manufacture of the flexible disk 1. This is particularly clear 2 out.

3 shows how a collar sleeve 9 is composed of two collar parts 9a, 9b. Each collar part 9a, 9b of the collar sleeve 9 includes a radially extending flange 9aa or 9ba, which is referred to here as a “collar”. A plurality of axially parallel and freely ending strips 9ab, 9bb are formed integrally on the inner edge of the annular collars 9aa, 9bb on the collar parts 9a, 9b. The strips 9ab and 9bb have such a width and such a distance from each other that they, like the 3 can be seen, when the collar parts 9a, 9b are arranged in opposite directions, they can be pushed into one another like a comb. This of course requires a corresponding angular orientation of the two parts 9a, 9b.

Like this in particular 3 and 4 As can be seen, the collars 9aa, 9ba of the collar parts 9a, 9b have a plurality of continuous slots 10 in the area of their inner edge, which are dimensioned and arranged so that the free ends of the strips 9ab, 9bb of the other collar part 9a, 9b the collar sleeve 9 can be passed through it, as is the case 4 can be seen.

The different thread packages 6, 7, 8 are placed on two collar sleeves 9 directly or in the form below using the 6 until 8th wound in the manner described in the state of the collar sleeves 9a, 9b, which is in 3 is shown. In this state, a relatively large axial height of the collar sleeves 9a, 9b is available for the resulting thread package 6 to 8. The axial winding height is not as in the DE 10 2008 047 596 A1 determined by the length of the bushing but by the axial dimension of the collar sleeves 9 and the length of the strips 9a, 9b, which extend beyond the length of the bushings 3.

As already mentioned, this winding process can in principle correspond to that which occurs when using conventional bobbins, for example according to the above-mentioned DE 37 34 089 A1 is used. However, it is not necessary here to wind the thread package with high thread tension to achieve a high specific force transmission cross section. In the present case, the high thread density is created by the fact that the collar sleeves 9 are in the state of 3 wound thread package is compressed by axial compression of the collar sleeves 9. This compression can reduce the axial dimension of the thread package by up to 50%.

During compression, the collars 9aa, 9ba of the two collar parts 9a, 9b of the collar sleeves 9 come closer together, with the strips 9ab, 9bb of one collar part 9a, 9b simultaneously pushing through the slots 10 of the other collar part 9b and therefore further survive above. If the desired compression of the thread package has been achieved (state of 4 ), the protruding areas of the strips 9ab, 9bb are folded over as shown 5 can be seen. In this way, the compression of the thread package lying between the collars 9aa, 9ba, which is in the 3 until 5 not shown for illustration reasons, “frozen” without the need for rubber coating or other bonding of the thread layers.

The resulting unit of two collar sleeves 9 with a thread package 6, 7 or 8 connecting these two collar sleeves is now transferred to two parallel bushings 3. This is how step by step the in 1 The structure shown in the front area is made up of bushings 3, collar sleeves 9 and thread packages 6, 7, 8 connecting them. This finished structure is finally cast with appropriate material, as is the case with the prior art, so that the elastomeric body 4 is created.

The winding process of the thread packages 6, 7, 8 and the construction of the collar sleeves 9 were explained above using the example of an elastic joint disk 1. However, they can of course also be used essentially unchanged in elastic torsion couplings.

In 6 The part of a device relevant in the present context is shown schematically, which is used for winding a thread package 6 to 8 in a novel and particularly advantageous manner and is marked overall with the reference number 101. This device 101 comprises a winding body 102, which in turn has a base plate 102a and one with the has a rigidly connected, for example one-piece, cylindrical winding projection 102b. The winding body 102 can be rotated about the axis of the winding projection 102.

On the lateral surface of the cylindrical projection 3 is in 6 an essentially finished intermediate product marked with the reference number 104 'has already been wound up. This intermediate product 104 'was created by guiding a thread 105 provided with a sticky substance around the cylindrical winding projection 102b with the aid of a winding finger 106 by rotating the winding body 102. The winding finger 106 pulls the thread 105, which is wound up to form the intermediate product 104', from a supply spool, not shown.

Since the intermediate product 104 'has the shape of a circular ring in the top view in the winding method shown here, the withdrawal speed of the thread from the supply roll is the same in all angular positions when the winding body 102 rotates. This is equivalent to saying that the thread tension is identical in all winding positions.

After the winding process in the device 101 has been completed 6 the intermediate product 104' can be removed from the cylindrical Wichel projection 102b. It then has the in 7 shown shape of a circular ring cylinder. The cohesion of the individual layers of the intermediate product 104 'is ensured by the sticky coating of the thread 105.

Two collar sleeves 109 of the design described above are then inserted into the interior of the intermediate product 104 'in such a way that the intermediate product comes to rest in the space provided for it between two collars 109aa. This is in 8th shown.

In a next step, which is not shown in the drawing, the intermediate product 104 'and the collar sleeves 109 are 2 compressed by pressurization in the axial direction. The dimension of the intermediate product 104' in the axial direction can be reduced by up to 50 percent, preferably about 30 percent. As a result of this compression, the individual turns of the thread 105 in the intermediate product 104 'move closer to one another, at least in the axial direction, so that the dimension of the intermediate product 104' is significantly reduced while the force transmission capacity remains unchanged.

After reaching the desired degree of compression, the collar sleeves 109 are in the axially shortened state, which is shown in 5 shown, locked.

In a next procedural step, which is in 8th is shown schematically, the intermediate product 104 'now has the desired oval shape. For this purpose, the intermediate product 104 'with the two collar sleeves 109 is inserted into a further device, which overall has the reference number 107. The device 7 comprises two circular cylindrical pins 111, 112, the central axes of which lie on a plane containing a diameter of the intermediate product 104 'and which can be moved towards and away from one another while maintaining their parallelism.

The pins 111, 112 have an outer diameter which corresponds to the inner diameter of the collar sleeves 109. You own in 8th the smallest distance from each other. They are then moved in the direction of arrows 110 with the help of a suitable motor drive 8th pulled apart, with two opposite areas of the intermediate product 104 'flattening accordingly. In this way, the final shape of the thread packages 6, 7, 8 is created, as shown in 1 is shown, in which the thread packages 6, 7, 8 have two opposite arcuate deflection areas and two parallel, opposite straight strands.

In the procedure described above, the intermediate product 104 'is compressed before it is deformed into the final oval shape of the thread package 6, 7, 8. In principle, however, it is also possible to first compress the thread package 6, 7, 8 in the oval shape. In some cases it is also possible to create the oval shape of the thread packages 6, 7, 8 from the circular cylindrical shape of the 2 only produced during the production of the elastic joint disc or the torsion coupling.

Claims (9)

Elastic rotary connection element with a) at least two fastening elements which have a tubular bushing; b) on each bushing at least one collar sleeve, each of which has an axially extending region and a radially projecting collar at both ends of this region; c) at least one oval-shaped thread package wound from a thread, which in turn comprises two mutually parallel strands and two opposite arcuate deflection areas; wherein d) the thread package is guided into the deflection area between the collars of a collar sleeve around its axially extending area; characterized in that e) the axially extending regions of the collar sleeves are shortened in the axial direction compared to an initial state by applying a force which compresses the thread package (6, 7, 8) between the collars of the collar sleeves. Elastic swivel connection element Claim 1 , characterized in that at least one collar sleeve is composed of two collar parts, each of which is provided with a collar, the axially extending region of at least one collar part comprising a plurality of spaced apart strips which are connected at one end to the respective collar and are passed with the opposite ends through slots (10) in the other collar part and fixed to it. Elastic swivel connection element Claim 2 , characterized in that both collar parts have stripes, the strips of one collar part and the strips of the other collar part interlocking like a comb. Elastic swivel connection element Claim 2 , characterized in that the areas of the strips passed through the collars are bent over for fixation. Elastic rotary connecting element according to one of the Claims 1 until 4 , characterized in that the collar sleeves are made of deep-drawn metal. Elastic rotary connecting element according to one of the Claims 1 until 4 , characterized in that the collar sleeves consist of an injection molding material. Method for producing an elastic rotary connection element, in which a) at least one thread package is placed around two collar sleeves, each of which has an axially extending region and a radially extending collar at both ends of this region; b) the assembly formed from the two collar sleeves and the thread package is mounted on two tubular bushings forming fastening elements, which are arranged at a distance from one another with parallel axes, by pushing on the collar sleeves; c) the bushings, the collar sleeves and the thread package are cast with an appropriate material to form an elastic body; characterized in that d) the winding of the thread package (6, 7, 8) onto the collar sleeves in step a occurs in a state in which the axially extending region of the collar sleeves has a first length; e) by applying an axial force while compressing the thread package (6, 7, 8) between the collars, the axially extending regions are shortened to a second, smaller length, after which steps b and c are carried out. Procedure according to Claim 7 , characterized in that f) the thread (105) is first wound onto a circular cylindrical projection (102b) of a winding body (2) to form an intermediate product (104 ') in the form of an annular cylinder; g) the intermediate product (104') is removed from the winding body (102); h) two collar sleeves (109) of greater length are introduced into the interior of the intermediate product (104') in their initial state; i) the collar sleeves (109) and the intermediate product (104') are compressed by applying a force so that the collar sleeves (109) obtain their shortened dimension in the axial direction; k) the collar sleeves (109) are moved apart before or after step i so that the thread package takes on an oval shape. Procedure according to Claim 8 , characterized in that the compression reduces the axial dimension of the intermediate product (104 ') or the thread package (6, 7, 8) by up to 50 percent.

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