The present invention relates to a tensioner which is adapted to adjust the tension of a filament which is supplied to a drafting stage of a ring spinning machine. Further, the present invention relates to a ring spinning machine in which the inventive tensioner is mounted.

Generally, the production of yarns via ring spinning is a well-known technique. One exemplary arrangement thereof is described in the following with reference to figures 1 to 3.

The prior art technique disclosed in EP 2 371 998 B1 shall be explained with reference to figures 1 to 3. A so-called drafting stage 100 is constituted by an upstream pair of rollers 2, 2’, a first pair of rollers 3,3’, and a second pair of rollers 5,5’. The definition upstream, first and second pair of rollers is only used in view of the present claim language. These pairs of rollers may also be identified from an upstream to a downstream side as first, second, and third pair of rollers.

A so-called roving a’ made of staple fibers is unwound from a first bobbin 107 and supplied to the drafting stage 100. In the example of EP 2371998 B1 as shown in figure 1 , two separate bobbins 107, 109 are provided, each one a respective roving a, a is unwound and feed to a guide 1 , 1’. First, these rovings a, are drafted between the upstream pair of rollers 2, 2’ and the first pair of rollers 3,3’, (e.g. figure 2 showing the top view of the drafting stage of figure 1).

Downstream of the first pair of rollers 3,3’, there is an apron 4 which guides the respective roving a, a to the second pair of rollers 5, 5’. From upstream of the second pair of rollers 5, 5 ^' , there are supplied two filaments b, b’ from respective bobbins 111 , 11 G to the drafting stage 100. Between the second pair of rollers 5, 5 ^' , each one of the respective rovings a, a is drafted together with the respective filament b, b ^' as shown in figure 3.

Due to the rotation of the spinning ring, the respective two strands are wound together to form a yarn Y as shown in figure 3.

Also, the adjustment of the tension of a filament is generally known.

A tension adjuster is generally described in CN 106702558 A. The tension adjuster in this document is constituted by a ring which is moved to adjust the tension of the filament, while the filament is guided through the ring.

A further tension adjuster of filaments is disclosed in CN 102336349 A.

The aforementioned documents CN 106702558 A and CN 102336349 A do not contain any specific description how the respective tension adjuster works. In particular, for ring spinning, when a roving is fed together with a filament to constitute a yarn, it is important to adjust the tension of the filament. The tension needs to be adjusted depending on the filament material type and on the thickness of the filament or the respective properties of the ring spinning machine. In particular, for dual core ring spinning in which it is provided a first and second filament which are fed to the drafting stage, it is important to adjust the tension of at least one or also both of the filaments.

The present invention provides a tensioner to adjust the tension of a filament supplied to a drafting stage of a ring spinning machine, which can be easily mounted on a ring spinning machine and/or which can be easily actuated and/or which has a simple design and/or is easy to assemble during the construction thereof.

According to a first aspect of the invention, this problem is solved with a tensioner having the features defined in claim 1 .

The tensioner has a first part and a second part. The first part has at least a first finger and the second part has at least a second finger. The first part is relatively moveable with respect to the second part. Due to this relative movement of the first and second part, the distance between the first and second finger can be changed. Therefore, it is possible that a tension of a filament, which is guided between the first and second fingers, is increased. This tension is increased because the distance between the first and second finger is increased due to the relative movement of the first part with respect to the second part in a direction perpendicular to the direction in which the filament extends between the first and second fingers. The filament can be easily guided through the fingers in a direction perpendicular to the extension direction of the fingers. By moving the respective fingers in different directions, the tension of the filament can be increased.

This tensioner is in particular provided at a dual core ring spinning machine. One or two of the first and second filament which are drafted together is/are thereby adjusted in its/their tension. It is beneficial, if one filament is an elastic filament and the other filament is an inelastic filament to adjust the tension of at least the inelastic filament and/or only this inelastic filament.

An improved guidance of the filaments can be provided when the first part has a third finger additionally to the first finger and/or when the second part has a fourth finger additionally to the second finger. Thus, the third finger is adapted to move simultaneously in the same direction as the first finger while the fourth finger is adapted to move simultaneously in the same direction as the second finger. Due to the relative movement of the first and third finger, with respect to the second and fourth finger, the tension of the filament, which is guided between the fingers, is increased. According to a further development, the fingers are interdigitating in the sequence of the first, second, third, and fourth finger, one after each other when viewed in the extension direction of the filament between the fingers. The respective filament can thus be guided in a slightly wound shape between the respective interdigitating fingers, such that the filament is guided always on a front side of the fingers, while the font side of the fingers mounted at the respective first and second part are facing each other. When moving the respective fingers, the tension of the filament which is guided through the fingers can be increased. The respective tensioner may also have more than in total four fingers. Any number of fingers, at least more than two fingers can be provided.

It is advantageous that the first part of the tensioner is pivotably mounted via a hinge to the second part. Due to the hinged connection, there is provided one pivot axis about which the first part can be rotated with respect to the second part, such that the respective fingers mounted on the first part are moveable with respect to the fingers mounted on the second part, such that the distance between the fingers mounted at the respective parts is increased at least in a direction perpendicular to the direction in which the filament extends between the fingers.

It may be the case that the second part is fixedly mounted on a base arm. The base arm serves as a means via which the tensioner can be mounted to a frame of the ring spinning machine.

The second part may be fitted to the base arm by a snap fit. This makes it possible to easily exchange the respective tensioner.

According to a further development, it may be the case that the first part has a bent section. This bent section protrudes from the first part at a side of the hinge distant from the side at which the respective fingers are fixed to the first part.

This bent section may have a first urging surface. This first urging surface may face an adjacent second urging surface provided at a second part of the tensioner. This second urging surface may be adjacent to the hinge. The first and second urging surface are facing each other, while an urging means, for example a coil spring, is mounted between the first and second urging surfaces.

Due to this configuration, the respective fingers of the different parts ( first and second part) are pressed by the urging means into a position where they are close to each other, compared to a distance between the respective fingers in a perpendicular direction perpendicular to the direction in which the filament extends between the fingers, when the tension of the filament is increased due to the relative movement of the fingers. Due to this urging, the respective first and second parts may lie flush against each other, such that there is a low tension provided to the filaments. When the respective first part is rotated about the hinge with respect to the second part, against the force of the urging means, the respective tension is increased (compared to the relatively low tension in the starting position).

The tensioner may have an adjusting actuator for adjusting the distance between the fingers, which are mounted at the respective first or second part.

The adjusting actuator may be configured to generate or impart a pressing force to the first part, such that the first part is pivoted via the hinge against the force of the urging means in order to increase the distance between the fingers at least in a direction perpendicular to the direction that the filament extends between the fingers. With this actuator, a simple adjusting of the tension can be provided.

This adjusting actuator may be constituted by a shaft which is rotatably mounted in a through opening, which through opening is provided in the second part. The through opening may extend parallel with respect to the pivot axis of the hinge and off-set therefrom. The shaft may have a cam section interacting with a protrusion of the first part. Due to the interaction of the cam section with the protrusion, upon rotation of the shaft, the cam section forces the protrusion of the first part to retract from the second part, such that the distance between the fingers, at least in the direction perpendicular to the direction which the filament extends between the fingers, increases.

The protrusion of the first part may extend into a hole of the second part, which hole extends orthogonal with respect to the through opening of the second part through which the shaft of the actuator extends. he shaft of the actuator may be provided at a rear side thereof with a manually grippable actuator knob. This actuator knob may have a scale indicating the distance between the fingers, at least in a direction perpendicular to a direction which the filament extends between the fingers and/or may indicate the tension applied to the filament which is guided between the fingers.

The respective actuator knob and/or the cam section may has at least three positions in which the respective distance between the fingers, at least in the direction perpendicular to the direction which the filament extends between the fingers, has a specific value. Between the respective positions, there is no intermediate position in which the knob and/or the cam section can have a steady state.

Therefore, there are distinct positions in which the actuator knob can be rotated or at which the cam section may be brought. At these position, the respective distance between the fingers, which distance determines the tension has a particular predetermined value. As this is indicated at the actuator by e.g. a scale, the user can easily see the respective tension applied. The respective positions may be indicated, when respective distinct values are provided as 1 , 2, 3, 4, 5, 6, and 7. For example, the higher the number, the higher the tension applied.

According to a further development of the invention, the first and third fingers can be formed as a unitary element and may be constituted by a bent metal rod. The respective first and third fingers may be fitted by a snap fit to a first part. The first part may be made of plastic material, e.g. by injection molding.

Additionally or alternatively, the second and fourth fingers may be made as a unitary member and may be made by a bent metal rod and/or may be fitted by a snap fit to the second part. The second part may be made of plastic material, e.g. by injection molding.

Thus, the first part, second part, as well as the base arm of the respective tensioner may be made of plastic material, for example by injection molding. The respective shaft of the actuator may also be made of plastic material or may be made of a metallic material. The respective actuator knob mounted on the shaft may be of plastic material and may be molded together with the respective shaft. If the shaft is made from metal, the metal shaft may be insert molded with the respective knob.

The respective base arm may have at its opposite end, which is opposite from an end at which a second part is mounted, a bracket for being attached to the frame of the ring spinning machine.

According to a further aspect of the invention, a ring spinning machine is provided.

The ring spinning machine has a filament supply for supplying a filament. Further, it is provided a roving supply for supplying a roving. It is additionally provided a drafting stage at which the filament and the roving are combined to form a respective yarn. The drafting stage has at least a first pair of rollers between which a roving supplied by the roving supply is drafted, a second pair of rollers which are downstream of the first pair of rollers wherein the filament from the filament supply is fed to the roving downstream of the first pair of rollers upstream of the second pair of rollers. The filament together with the roving is fed through the second pair of rollers. A spinning ring on which the yarn generated by the roving and the filament is wound is further provided. The ring spinning machine is characterized by comprising the inventive tensioner explained in the foregoing section. The tensioner may be mounted to a frame of the ring spinning machine in a position downstream of the first pair of rollers and upstream of the second pair of rollers.

The ring spinning machine may be a dual or multiple core ring spinning machine. E.g. at least one filament defining the core of the yarn may be an elastic filament and at least one filament defining the core may be an inelastic filament. The roving may define a cover layer of the yarn.

Usually the tension of one or more of the filaments of the dual or multiple core yarn changes during spinning as the diameter of the coil or bobbin from which the filament is fed decreases. To provide a smooth and reliable covering with a cover layer which may be made from staple fibers it is important to adjust the tension of at least one or more or all of the filaments which make up the core of the dual or multiple core yarn. For at least one or several or each filament of the core a respective inventive tensioner may be provided. Each tensioner may adjust independently the tension of the respective filament.

In particular, with the inventive tensioner there may be adjusted the tension of the inelastic filament. Alternatively or additionally the tension of the elastic filament may be adjusted with a respective tensioner. Although the foregoing section a respective tensioner and a ring spinning machine having the inventive tensioner is described, the present invention may also provide a method for adjusting tension of a filament. The aforementioned constructive features of the system can in this case be provided as method feature.

In the following, further details of the invention are explained with the help of the figures, which explain some non-limiting embodiments of the present invention.

Figures 1 to 3 show a conventional ring spinning system as it is disclosed in EP 2 371 998.

Figure 4 shows an example of the inventive ring spinning machine, which comprises the inventive tensioner.

Figures 5 to 13 show different views and parts of the respective tensioner which is mounted to a frame of the ring spinning machine.

Herein, figure 5 is an oblique view from a rear side of the base arm while figure 6 is an oblique view from a front side.

Figure 7 is a plane view from the side where the first part has the bent section.

Figure 8 is a plane view from the side to which the fingers extend.

Figure 9 shows how the respective first and second part is attached to the base arm. Figure 10 shows the respective front part of the base arm on which the respective second part is mounted by snap fit.

Figure 11 shows the respective first part and the actuator having a rod and a knob.

Figure 12 shows the second part and the shaft of the actuator.

Figure 13 shows a part of the second part in figure 12. Figure 14 shows an end part of the actuator shaft with the cam section.

Figures 1 to 3 show a conventional ring spinning system as it is disclosed in EP 2 371 998 B1. The inventive tensioner can also be mounted to a frame of said system to adjust the tension of one or both of the respective filaments b, b ^' . The disclosure of the system disclosed in EP 2 371 998 B1 is incorporated herein by reference.

Roving

Generally a roving is a long and narrow bundle of fiber. Rovings may be produced during the process of making spun yarn from wool fleece, raw cotton, or other fibres.

The roving may be set up of staple fibers. The staple fibers may comprise at least one or a mixture of fibers from the group of: natural, recycled and/or synthetic fibers and/or fibers made of the following materials: cotton, viscose, polyester, wool, linen, alpaca, vicuna, angora, cashmere, kapok, manila, flax, hemp, ramie, hessian, sisal, coir, asbestos, glass, azlon, acetate, triacetate, acrylic, aramid, polyamide, olefin. The respective fibers made of the aforementioned material may be used as a single material fiber mixture or a composition of any one of the aforementioned different material fibers in one of different lengths.

The roving in the ring spinning process forms the cover layer of the yarn. Due to this cover layer, the yarn feels comfortable and natural while it is combined with elastic properties.

Filament

A filament is an infinite fiber which may be used in the ring spinning as core of the yarn.

The inventive ring spinning system may be in particular a ring spinning system for a dual or multiple core yarn. Therefore, there may be provided a first and second filament which are fed to the drafting stage.

One or more of these multiple filaments may be an elastic filament and one or more of these multiple filaments may be an inelastic filament. The inelastic filament can be made from a material chosen from the group of Polyester, Polyamid, Polyether Sulfones , Polybutylene Terephthalate (PBT), Partial Oriented Yarn (POY), and/or a mixture thereof. It is also possible to use as further filament any natural or synthetic filament.

The elastic filament may be filament having any elasticity, for example an elastane yarn. The used elastane filaments may be filaments sold under the trademark from the respective company (e.g. company is given in the following in brackets): LYCRA (DuPont), SPANDEX (Monsanto), CREORA (Hyosung) and filaments from HUAFON which are in the following called HUAFON filaments, the material of the HAUAFON filaments may be sold under the trademark QIANXI.

Elasticity is the ability to deform reversibly under stress. The elasticity may have an elastic modulus, the Young’s modulus (in GPa) of 0.01 to 5, more preferably 0.01 to 0.5 in particular, 0.01 to 0.1 . Alternatively or additionally, the elongation may be in the range of 3 to 22%. Wherein the % value defines the relative elongation from a relaxed state to a state where the yarn is expanded to the maximum where a reversible contraction can still occur. Further preferred elongations are: 4%, 6%, 8%, 10%, 13%, 15%, 18%, 20%. The aforementioned values may each separately serve as lower or upper limits.

It is advantageous to at least adjust the tension of the inelastic filament and/or the elastic filament. It may be beneficial that the tension of both the elastic and inelastic filaments are adjusted independently with a respective tension device which is described in the following.

Dual Core Ring Spinning System

Figure 4 shows an example of a ring spinning machine according to the present invention.

The ring spinning machine has a drafting stage 100. The drafting stage contains three pairs of rollers for using the same terminology as in the claims, the most upstream pair of rollers is identified as the upstream pair of rollers 2, 2 ^' . The most downstream pair of rollers is identified as the second pair of rollers 5, 5 ^' . The pair of rollers the middle are identified as first pair of rollers 3, 3 ^' . A roving 140 is wound about a first bobbin 107. A first filament 106 is wound about a second bobbin 109 and a second filament 106 ^' is wound about a third bobbin 111. The roving 140 is guided through a roving condenser 112 before it is fed to the upstream pair of rollers 2, 2.

After the respective roving is drafted between the upstream pair of rollers 2, 2 and the first pair of rollers 3, 3 ^' it is fed to the second pair of rollers 5, 5.

Simultaneously, the first filament 106 and the second filament 106 ^' are also fed downstream of the first pair of rollers 3, 3 ^' and upstream of the second pair of rollers 5, 5, between the nip of the second pair of rollers 5, 5, such that the respective filaments ^' and the roving 140 is drafted to for the dual core yarn, which is then fed to the spinning ring 141.

In figure 4, the second filament 106 ^' is guided from the third bobbin 111 through a guide element 116 and then through the inventive tensioner which is identified with reference sign 117.

The tensioner is mounted on a frame (which is not visualized in said figure) of the ring spinning machine. This frame may have a rod on which the bracket 136 of the base arm 118 of the tensioner 117, which is explained later, may be mounted.

In the present case the second filament 106 ^' is an inelastic filament and the first filament 106 is an elastic filament. The tensioner may additionally or alternatively be mounted such that the tension is applied to the elastic filament. The invention is however not delimited only to the situation shown in figure 4 and each feature described in throughout the description can be extracted and is thus not inextricably linked to the other features.

The respective inventive tensioner may be mounted downstream of the first pair of rollers 3, 3 ^' and upstream of the third pair of rollers 5, 5 ^' in a region shortly upstream of a location where the first and second filaments are fed together with the roving.

Usually the tension of one or more of the filaments of the dual or multiple core yarn changes during spinning as the diameter of the coil or bobbin from which the filament is fed decreases. To provide a smooth and reliable covering with a cover layer which may be made from staple fibers it is important to adjust the tension of at least one or more or all of the filaments which make up the core of the dual or multiple core yarn. For at least one or several or each filament of the core a respective inventive tensioner may be provided. Each tensioner may adjust independently the tension of the respective filament.

In particular, with the inventive tensioner there may be adjusted the tension of the inelastic filament. Alternatively or aditionally the tension of the elastic filament may be adjusted with a respective tensioner.

Tensioner

Figures 5 to 14 show different views and sections of an exemplary embodiment of the inventive tensioner.

Flowever, the present invention is not delimited to the particular embodiment and also each feature defined in the independent dependent claims is inextricably linked to the further features and, therefore, the invention can be constituted by each feature described in the following separately. Although there may be some technical relation of some of the features in the specific embodiment, it is not necessary to define the relation in the claims because in the broadest sense of the invention, each feature can be claimed alone and/or together with other features.

In figures 5 to 8, there is given a coordination system.

Herein, the x axis corresponds to the axis in which the base arm 118 extends (seen from the second part 119 in the direction to the bracket 136). The z axis corresponds to the direction in which the filament 110 extends and is perpendicular to the x axis. The y axis corresponds to the direction in which the respective arms 126, 127, 128, 129 extend. The respective axis are identified for illustrating purposes.

The respective x-y plane defines for illustrating purposes a horizontal plane. The respective z axis is defined as a vertical direction.

The tensioner 117 comprises a base arm 118. On the base arm there is mounted via a snap fit a second part which has reference sign 119. The second part 119 may be mounted to the (distal) end of the base arm 118 which is shown in figure 7 on the left hand side. The second part can be fitted from the front side to the (distal) end of the base arm 118. The snap fit is constituted due to the snapping protrusion shown in figure 10, which figure shows a part of the base arm. It is not necessary to provide such a snap fit between the second part 119 and the base arm 118. It may also be the case that the second part 119 and the base arm 118 are formed as unitary member or otherwise mounted together.

The tensioner further has a first part which is identified with reference sign 121 and is mounted via a hinge 122 to the second part 119. The hinge is constituted by two hinge ears 123 which are formed as unitary member with the second part 119. The hinge 122 is further constituted by a hinge pin 124, which is mounted on the first part 121.

The first part 121 , the second part 119, and the base 118 may be made from a plastic material, for example by injection molding.

The hinge pin 124 may be made from metal and may be fixed by injection molding to the first part 121.

The first part 121 has a box shape and at a rear side of the box shape there is provided a so- called bent section 125 (e.g. Fig. 5). This bent section 125 protrudes from the first part 121 at a side of the hinge 122 distant from the side at which the first and third finger 126, 127 are fixed to the first part 121 . As derivable from figures 6 and 9, between the bent section 125 and a wall of the second part 119 a coil spring 130 serving as urging means is provided. The respective coil spring 130 is held in place by a protrusion protruding from the second part 119 in the region of an second urging surface 138. The respective coil spring 130 is mounted between the second urging surface 138 of the second part 119 and a first urging surface 137 provided at the bent section 125 of the first part 121 . The respective coil spring 130 urges the first part 121 to pivot with respect to the second part 119 that the first and second part come close together in the region of the fingers 126, 127, 128, 129.

The respective first part 121 has at a side distant from the hinge 122 a first finger 126 and a third finger 127 which protrude in the y direction perpendicular to the z direction and the x direction in the figures. The second part 119 has corresponding fingers identified as second finger 128 and fourth finger 129. The respective fingers 126, 127, 128, 129. are interdigitating with each other in a row in the z direction starting with the first finger 126 at the first part 121 , the second finger 128 at the second part 119, the third finger 127 at the first part 121 and the fourth finger 129 at the second part 119. The respective fingers 126, 127 of the first part are bent at their distal ends in one common direction which is a different direction (opposing direction) in which the distal ends of the fingers 128, 129 of the second part 119 are bent.

The respective filament 110 which is guided as schematically shown in figure 5, extends on a front side of the respective fingers, wherein the front side of the respective fingers are the sides of the fingers at the respective part which face each other in the x direction.

The respective tensioner 117 in the present case has on the second part 119 also a fifth finger 142 which is bent downwardly in the reverse z direction. This finger provides a further guiding of the filament 110 before the respective filament 110 is guided to the drafting stage 100.

As derivable from figure 11 , which shows an inside view onto the actuator 131 which is described later and the first part 121 , the respective first and third finger 126, 127 is constituted by a metal rod which is bent into a general u-form. The respective fingers 126, 127 are held by a snap fit on the first part 121. A corresponding fixation of the second and fourth fingers 128, 129 is also provided at the second part 119 which is not shown in the figures.

On the top side in figures 5 and 7 to 9, there is provided an actuator knob 132. The actuator knob 132 as shown in figure 11 is connected to the shaft 133 which has at a lower side thereof a cam section 134. The cam section is constituted by a groove formed in the shaft 133. When the actuator knob 132 is rotated, the shaft 133 is rotated correspondingly in a through opening provided in a second part 119. Thereby the cam section 134 is rotated. The cam section 134 thereby interacts with a protrusion 135 extending from an inner side of the first part 121 (see figure 11 ). Thereby the first part 121 is rotated about the hinge 122 such that the respective finger distance between the respective fingers 126, 127, 128, 129 is increased in the direction perpendicular to the direction in which the filament 110 extends through the fingers 126, 127, 128, 129 (the distance between the fingers is increased in x direction).

In the particular example, the shaft 133 extends in the z direction.

The respective shaft is mounted parallel to the pivot axis R defined by the hinge pin 124. The respective cam section 134 has four flat faces. Each of these flat faces has a different distance from the outer circumferential surface of the shaft 133 thereby the respective protrusion 135 is pushed at a retracted position at the four specific distances corresponding to the respective flat faces of the respective cam section 134. Due to the constitution of these four faces, the respective knob has four positions indicated by the indices 1 , 2, 3 and 4 in the figures. In each position 1 , 2, 3, 4 , one specific tension value is generated, which is defined by a specific distance between the respective fingers.

In the figures it is shown that the actuator knob 132 has protrusions on which numbers/indices 1 , 2, 3, 4 are given. These numbers give an indication to the operator that he can manually adjust the tension. In the particular example, the increasing numbers 1 , 2, 3, 4 show an increasing tension. The respective four positions of the cam section 134 is only an example. The respective tension can be not only increased in steps but can also be increased constantly. In the specific example, between the respective positions there is not intermediate position in which the actuator knob 132 or the cam section 134 has a steady state.

The respective base arm 118 has on a rear side thereof which is a side distant from the side in which the tensioner 117 is provided a bracket 136. With this bracket 136, the respective tensioner 117 can be mounted on the frame of the ring spinning machine. In the particular case the respective bracket 136 can be snapped to the frame of the ring spinning machine.

Further variants of the invention may be as follows.

Instead of the manually operated tensioner, the respective tensioner may be automatically controlled via e.g. a PC. The respective tension may be adjusted based on a feedback loop in which the actual tension of the filament is measured.

The actuator is not delimited to an actuator having a shaft. Any actuators may be used to adjust the distance between the fingers. Also an electrically controlled actuator may be used.

Instead of the respective two fingers at each of the respective parts, there may be provided only one finger or three or more fingers at the respective part. Although, in the present case it is described that the first part is rotated with respect to the second part (pivoted), it is not necessary to provide a pivotable movement. It can also be provided translational movement wherein the first part is translated with respect to the second part.

Although in the present case, the respective fingers are made from a different material as the respective first and second part, they may be made from the same material as the respective part and may be formed as unitary part thereof. Instead of a finger there may be used any means which allows it to take the filament there between and to adjust the tension by the relative movement of two parts of the tensioner.

The respective embodiment is only described for illustrative purposes and the invention is not delimited to the particular embodiment.

Reference Signs

1 , V Guide

2, 2 ^' upstream pair of rollers

3, 3 ^' first pair of rollers 4 apron

5, 5 ^' second pair of rollers 100 drafting stage a, roving b, b ^' filament 107 first bobbin 106 first filament 109 second bobbin 106 ^' second filament

111 third / fourth bobbin

112 roving condenser twist controller guide element tensioner base arm second part snapping protrusion first part hinge hinge ears hinge pin bent section first finger third finger second finger fourth finger coils spring adjusting actuator actuator knob shaft cam section protrusion bracket first urging surface 138 second urging surface

R pivot axis

139 hole

140 roving

7, 141 spinning ring Y Yarn

142 fifth finger