Winder

Abstract

The invention relates to a winder for winding a thread or yarn to a winded package comprising at least one spindle and a pressure roller. The distance of the pressure roller from the spindle is dependent on the movement of the spindle or the pressure roller along a degree of freedom. The pressure roller is pressed against the outer circumference of the winded package. The spindle or the pressure roller is connected to a drive unit for rotating the same. The thread is supplied to the winded package in a contact area between the pressure roller and the winded package. An actuator is linked with the pressure roller or the spindle such that a force produced by said actuator influences the contact force between the pressure roller and the winded package. The actuator produces a constant force (FN). At least a component (FFHG) of the force (FN) of the actuator is directed along a translational degree of freedom. The relation between the component (FFHG) and the force (FN) depends on the distance between the spindle and the pressure roller. The actuator influences a normal force (FN) in a hinged pillar. The hinged pillar is inclined with an angle α in respect of the translational degree of freedom. The angle α depends on the distance of the spindle from the pressure roller.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending German Patent Application No. DE 10 2006 054 980.5 entitled “Spulmaschine”, filed Nov. 22, 2006.

FIELD OF THE INVENTION

The present invention generally relates to a winder for winding a yarn or thread (in the following “thread”) to a winded package.

BACKGROUND OF THE INVENTION

European Patent No. EP 1 213 246 B1 discloses a winder for winding a thread to a winded package. The winder comprises a turret head rotating around a horizontal axis. The shape of the turret head in a first approximation might be described as disc-like wherein the disc holds two separately driven spindles. A rotation of a spindle is used for winding a thread to a winded package. During winding the thread to a winded package at a rotating spindle located in an upper position a bobbin with the winded package might be removed from the other spindle located in a lower position. Furthermore, the spindle located in the lower position might be prepared for a future winding process, e.g. by passing a core over the spindle. When finishing the winding process for the spindle located in the upper position the turret head is rotated by an angle of 180° and a new winding process is initiated. The thread is delivered to the spool or the winded package in the contact area of a pressure roller and the winding package. The pressure roller is rotatably supported by a frame. The frame comprises a translational degree of freedom directed in vertical direction. For providing such translational degree of freedom the frame is guided by two guiding rods being oriented in vertical direction. An actuator is interposed between the frame and a housing of the winder. The actuator is a pressurized piston-cylinder-unit and produces a force that is directed along the aforementioned translational degree of freedom and acts upon the frame. The contact force of the pressure roller with the winded package results from the superposition of the vectors of the weight of the frame and the pressure roller and the force of the piston-cylinder-unit directed in opposite direction. A change of the diameter of the winded package leads to an increase of the weight of the winded package. By means of a suitable control of the pressure acting upon the piston-cylinder-unit an increase of the weight of the winded package with an increased diameter of the winded package might be compensated such that the contact force between the pressure roller and the winded package is held to be constant. The used control unit comprises an electromagnetic control valve controlling the supply of pressurized air to the piston-cylinder-unit. Furthermore, the control unit comprises a source of pressurized air, a control circuit, an adaptation unit for choosing a suitable constant contact force and sensors for sensing the actual forces. A control of the pressure and the control force holds the contact force within a small tolerance from a fixed value, wherein the tolerance is held below ±3%.

Furthermore, EP 1 213 246 B1 discloses an alternative embodiment wherein the degree of freedom between the spindle with the winded package and the pressure roller is not a translational degree of freedom but a rotational degree of freedom: the pressure roller is rotatably supported by the frame, wherein the frame itself is rotatably supported by the housing so that the frame builds a pivoting arm. The piston-cylinder-unit is linked with the pivoting arm. The lever arm of the force produced by the piston-cylinder-unit is held constant by the pivoting arm being designed and arranged such that an increase of the diameter of the winded package does not result in a pivoting movement of the pivoting arm. For that aim, the turret head is slightly rotated with an increase of the diameter of the winded package. The rotation of the turret head is chosen such that the contact point of the pressure roller with the winded package remains independent on the diameter of the winded package.

German Patent Application No. DE 197 05 262 A1 discloses a method for controlling the contact force under consideration of the relation of the number of revolutions of the pressure roller to the number of revolutions of the winded package. The control minimizes slippage between the pressure roller and the winded package.

German Patent Application No. DE 102 53 489 A1 addresses the shortcoming that a change of the relative position of a winded package from a pressure roller results in a change of the component of the weight acting upon the winded package. DE 102 53 489 A1 intends to minimize such changes of the component of the weight acting upon the winded package. The winder is equipped with complex sensor units for measuring the changing contact forces. The measured contact forces are used for adapting the force of the actuator in order to hold the contact force constant. DE 102 53 489 A1 also suggests an embodiment without any such sensor unit for measuring the contact force: for such embodiment the relationship between the relative position of the pressure roller from the winded package and the effective component of the weight is modeled. By sensing the relative position by a suitable displacement sensor the change of the force of the actuator required for producing a constant contact force might be calculated. Also, these embodiments known from DE 102 53 489 A1 base on the assumption that the actuator has a constant lever arm at a pivoting arm. Changes of the diameter of the winded package are compensated by a movement of the turret head. According to DE 102 53 489 A1 winders having a relative movement between the pressure roller and the winded package, being guided by linear guideways and having only one spindle are only suitable for use for a discontinuous winding of the thread.

Also German Patent Application No. DE 10 2005 005 096 A1 bases on the assumption that the contact force between the pressure roller and the winded package is to be held constant. The patent application suggests providing a manipulable control mechanism. Such manipulable control mechanism is manipulated by a worker for adjusting the contact force.

German Patent Application No. DE 10 2004 032 514 A1 discloses a cross-wound package rotatably supported by a frame. The frame is rotatably supported by the housing. Due to the center of gravity of the frame and the spool being located eccentrically, the frame builds a pendulum wherein such pendulum is supported by a pressure roller in a lying configuration of the pendulum so that the weight of the frame and the spool is counteracted by the contact force of the pressure roller. With an increase of the diameter of the cross-wound package the angle of displacement of the lying pendulum changes. Due to the increasing weight of the cross-wound package the contact force between the cross-wound package and the pressure roller increases. For compensating such changes of the contact force, an actuator acts upon the frame. The lever arm of the actuator changes with an increase of the diameter of the cross-wound package, i.e. with an increase of the angle of displacement of the lying pendulum. The geometrics are chosen such that for a minimal diameter of the cross-wound package the actuator produces a torque that increases the contact force of the cross-wound package and the pressure roller. For a larger diameter the lever arm has decreased to zero. A further increase of the diameter of the cross-wound package leads to a change of the direction of the torque resulting from the actuator so that the actuator leads to a decrease of the contact force of the cross-wound package with the pressure roller. Such counteracting torque might compensate an increase of the weight of the cross-wound package with an increase of the diameter. DE 10 2004 032 514 A1 discloses also a drive unit for changing the geometrics when starting the winding process or during the winding process. The aforementioned actuator is an air spring. The position of equilibrium of the air spring is adjusted by adjusting the pressure in the air spring wherein the pressure is secured to a constant value by a check valve. The pressure might be changed at the beginning of a winding process.

A similar embodiment is known from German Patent Application No. DE 41 21 775 A1, corresponding to U.S. Pat. No. 5,409,173, wherein according to that document additionally to a spring a pressurized piston-cylinder-unit acts upon a frame.

U.S. Pat. No. 3,672,584 and U.S. Pat. No. 3,672,583 disclose a winder with a fixed axis of rotation of the pressure roller. Here, the spindle is supported as a vertical, inverted pendulum. At the beginning of the winding process the winded package is supported approximately in a 1 o'clock-position of the pendulum by the pressure roller. With an increase of the diameter of the winded package the pendulum moves over the unstable position of equilibrium corresponding to the 12 o'clock-position. In the end of the increase of the diameter the pendulum reaches an 11 o'clock-position. The weight of the inverted pendulum provides a maximal force increasing the contact force between the pressure roller and the winded package in the 1 o'clock-position. Such increasing force reduces to zero in the 12 o'clock-position. With a further increase of the diameter of the winded package the weight produces a torque acting upon the inverted pendulum that decreases the contact force between the winded package and the pressure roller. The relationship between the contact force and the diameter might additionally be influenced by a plurality of springs. Such springs are linked at different positions with the housing of the winder. At the opposite ends the springs are linked at different positions of the pendulum. The springs might be oriented under different angles and might also only be effective in a part of the whole movement of the pendulum. The design of the springs and the choice of the linking points with the pendulum and the housing are chosen such that an increasing diameter of the winded package leads to a decreasing contact force between the pressure roller and the winded package.

Further prior art is known from DE 10 2005 003 334 A1 and DE 601 16 243 T2, corresponding to U.S. Pat. No. 6,622,956.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a winder for winding a thread to a winded package, wherein the contact force characteristic between a pressure roller and a winded package is designed for the winding process in a simple, but reliable way.

The novel winder might be designed according to the features of independent claim 1. Further embodiments of the novel winder result from the dependent claims 2 to 6.

The invention bases on the finding that, other than in the prior art summarized above, the assumption that the contact force between the pressure roller and the winded package is held to be constant during the winding process is not suitable for specific winding processes and winded products. Furthermore, it has been discovered that the mechanical properties of the “counter support” for the pressure roller built by the winded package change with an increasing diameter of the winded product, e.g. the stiffness of such counter support decreases with increasing diameter. Furthermore, the application of large contact forces for large diameters of the winded package might lead to an undesired convex outer contour of the winded package. Other embodiments of the invention base on the finding that constructions known from the above prior art for producing a (constant) contact force require a suitable control of the actuator including complex and costly measurement and control systems. These designs increase the complexity of the construction, the sensitivity of the winder to failure, the intensity of maintenance, the expenses for calibrations of used sensors and the overall complexity of the winder.

The present invention might also base on the finding that known winders basically use two general types of techniques:

A. Winders with a Rotational Degree of Freedom Between the Spool or Spindle and the Pressure Roller

For these types of winders the weight of the rotated body (in particular of the spool and the winded package having a weight changing during the winding process or the pressure roller with a suitable holding device or frame) influences the contact force between the pressure roller and the winded package dependent on a trigonometric function of the angle of rotation. Any control of the contact force for winders of such type has to consider a non-linearity. The non-linearity increases the complexity of the design of the winder and/or of the control during the winding process. Winders of that type are disclosed in documents DE 197 05 262 A1, DE 102 53 489 A1, DE 10 2005 055 096 A1, DE 10 2004 032 514 A1, U.S. Pat. No. 3,672,584 A, U.S. Pat. No. 3,672,583 A and DE 41 21 775 A1. In case of the generation of a torque for increasing or decreasing the contact force by an air spring or a combination of a spring with a piston-cylinder-unit according to DE 10 2004 032 514 A1 or DE 41 21 775 A1 the design or prediction of the contact force between winded package and pressure roller requires the consideration of another non-linearity including trigonometric functions of the angle of the force of the air spring and/or the piston-cylinder-unit. Furthermore, a non-linear dependency of the effective lever arm has to be considered. Embodiments of winders with a rotational degree of freedom require the measurement of the angle of rotation along the rotational degree of freedom for a control of the actuator in order to model the transfer of the force of the actuator under consideration of the above trigonometric functions in the control system. In summary, also actuators producing a constant force lead to a changing influence of that force to the contact force which is dependent on the angle of rotation of the frame or pendulum. In case of an optimal design, such dependency might lead to a desired force characteristic. However, such force characteristic depends on the geometry and cannot be changed before or during a winding process. In case of a non-optimal design, such dependency leads to an undesired force characteristic that requires an additional control of the force of the actuator or means for influencing the force transfer from the actuator to the pendulum.

B. Embodiments with a Translational Degree of Freedom

Embodiments with a translational degree of freedom are described in documents EP 1 213 246 B1, DE 10 2005 003 334 A1 and DE 601 16 243 T2. For these embodiments generally the influence of the weight of the winded package or the pressure roller is independent on the displacement along the translational degree of freedom. Accordingly, the consideration of the weight in a control and for the design is quite simple. In particular, the design and the control do not require a consideration of a non-linearity due to a trigonometric function. For embodiments having a rotational degree of freedom, a linear actuator always produces a force component that does not act along the degree of freedom so that there is always produced a force component that does not contribute to the contact force. Instead, prior to the present invention the person with skill in the art for winders for embodiments with a translational degree of freedom always followed the route to align a linear actuator with the translational degree of freedom in order to increase the efficiency of the actuator. On the basis of such alignment the actuator does not produce any force component that does not influence the contact force. The route driven by the person with skill in the art described above leads to the effect that any variation of the contact force between the winded package and the pressure roller has to be caused by a control of the force of the actuator.

The present invention leaves the above described route. For an embodiment with a translational degree of freedom the invention accepts the ostensive disadvantage of only using a component of the force of the actuator for influencing the contact force instead of using the whole force of the actuator. Such ostensive disadvantage is at least partially compensated by using an actuator having a constant force that might be built without any control or might be controlled to a more or less constant value.

Instead of accepting the above described non-linearities in the form of trigonometric functions as an unavoidable negative effect that should be cancelled out by additional measures surprisingly the present invention uses these non-linearities for automatically influencing the transfer path of the force of the actuator. On the basis of such finding the novel winder might be designed in a very simple but effective way.

According to the invention, an actuator might be used that produces (at least for one winding process) a constant force. It is possible that the produced constant force of the actuator varies for different winding processes or winded products. In the sense of the present invention “a constant force” is a force lying within predetermined limits. Examples for such limits are ±8%, in particular ±5%, ±3% or ±1% from a desired value.

A contact force changing during the winding process is produced in spite of using an actuator producing a constant force. This is due to the fact that the force of the actuator is not aligned with the translational degree of freedom but acts under a varying angle. Accordingly a varying component of the force produced by the actuator acts along the translational degree of freedom. The percentage of the force produced by the actuator building this component is not constant during the winding process but varies depending on the distance between the spindle and the pressure roller, so depending on the diameter of the winded package and the movement along the degree of freedom. The aforementioned dependency results in a varying contact force of the pressure roller at the winded package.

The present invention leaves the common approach of the persons with skill in the art of aligning the actuator with the translational degree of freedom for an optimal efficiency of the force and power of the actuator. Instead, only a component of the force is used, whereas another component of the force is ineffective. The division of the force of the actuator into the two aforementioned components provides the possibility of influencing the contact force dependent on the diameter of the winded package and the distance of a spindle from the pressure roller. In some cases, a complex sensor unit for measuring the distance of the spindle and the pressure roller and/or for measuring the contact force as well as a control depending on a measured sensor signal is not necessary.

A “thread” or “yarn” in the sense of the present invention e.g. might be a thread or yarn in the classical sense being a rotated, spun or twinned fabric. For another example, the “thread” or “yarn” might also be any other elongated winding product.

In the novel winder, the translational degree of freedom might be oriented in vertical direction. In case of the translational degree of freedom corresponding to the feeding direction of the thread, a movement of the pressure roller along the translational degree of freedom with an increase of the diameter of the winded product does not change the angle for applying and feeding the thread to the pressure roller. In case of the pressure roller having a traverse mechanism or traverse cam guidance (in the following “traverse mechanism”), the novel design results in constant contact conditions between the traverse mechanism and the thread. In case of the traverse mechanism expanding or fending out the thread, a change of the aforementioned angle might influence the expanding or fending process of the thread so that the thread is positioned on the outer circumference of the winded package in an undesired condition and shape. Furthermore, due to a change of the aforementioned angle the feeding area of the thread at the traverse mechanism might shift. Such shift changes the position and angle under which the thread is positioned at the winded package.

In another aspect of the invention, a simple coupling of the division of the force of the actuator into an effective component acting along the translational degree of freedom and an ineffective component with the movement along the translational degree of freedom is given in case of using a hinged pillar having an inclination angle α in respect of the translational degree of freedom, wherein the angle α depends on the distance of the spindle from the pressure roller or the diameter of the winded package.

A “hinged pillar” according to the invention is a constructive element being subjected only with external forces in its end regions and transferring only longitudinal forces between the end regions with negligible transverse forces.

By use of a hinged pillar under a varying angle α and the resulting transfer path of the force and the resulting geometric properties the force component acting along the translational degree of freedom depends on a trigonometric function of the angle α and the normal force in the hinged pillar. In case of influencing the normal force in the hinged pillar by the actuator, the dependency of the force component acting along the translational degree of freedom on the movement along the degree of freedom might be modeled realized in a very simple manner.

The hinged pillar might also be built by the actuator itself wherein the actuator in a first end region might be linked under a variable angle with the housing of the winder and in as second end region of the actuator might be pivotably linked under an angle α in respect of the translational degree of freedom directly or indirectly with the pressure roller.

It is also possible that one end region of the hinged pillar is guided in a guideway along the translational degree of freedom whereas the opposite end region of the hinged pillar is guided in another guideway that is inclined in respect of the first guideway, e.g. under an angle of 90°.

In another aspect of the invention, the actuator is a pressurized piston-cylinder-unit, e.g. a pneumatically activated piston-cylinder-unit. It is also possible that a plurality of piston-cylinder-units is pressurized from one single source of a pressurized fluid in case that the winder comprises a plurality of winding stations for winding a plurality of threads to a plurality of winded packages. Furthermore, further components for circuits with pressurized fluids, e.g. pneumatic valves, are available at low costs for providing a constant pressure resulting in a constant force of the actuator. Furthermore, such components for circuits for pressurized fluids are reliable also for long terms. In case that the dependency of the force component acting along the translational degree of freedom is to be varied for one and the same winding process or for different winding processes, the location of the link(s) of the hinged pillar with the housing or the pressure roller might be variable. Such variation might be caused manually by the user by choosing one of a plurality of receptacles or bores or under use of a long slot or elongated hole or the like. However, it is also possible that the linking point of the hinged pillar is automatically changed, e.g. under use of a step motor.

Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and the detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention, as defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. In the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 shows a partial sectional side view of a winder according to the invention.

FIG. 2 shows a sectional view II-II of the winder according to FIG. 1.

FIG. 3 shows an actuator building a hinged pillar used for influencing the contact force between the winded package and the pressure roller.

FIG. 4 shows a partial sectional view, the sectional view taken transverse to the longitudinal axis of the spool showing a pressure roller and a traverse mechanism.

FIG. 5 shows a schematic diagram of a pneumatic circuit for providing an (approximately) constant pneumatic pressure for an actuator built by a pneumatic piston-cylinder-unit.

DETAILED DESCRIPTION

Referring now in greater detail to the drawings FIG. 1 illustrates a partial sectional side view of a winder 1. The winder 1 is used for winding a thread or yarn 2 upon a spool 3 to a winded package 4. The winder 1 comprises a turret head 5 (see FIG. 2) built with a disc. The disc holds two spindles 6, 7 being located at opposite positions from the longitudinal axis of the disc. The spindles 6, 7 are separately driven by drive units 8, 9 and might be rotated relative to the turret head 5 around their longitudinal axes. Cores 10, 11 are passed over the spindles 6, 7. On these cores the thread 2 is winded to a winded package 4. On top of the spool 3 a guiding unit 12 for the thread is located wherein the guiding unit 12 builds a traverse mechanism due to the fact that the guiding unit 12 is supported by a guideway 13, e.g. a linear guideway or a plurality of guideways with a degree of freedom 14. The guiding unit 12 comprises a traverse mechanism 15. The traverse mechanism in a section 16 of different angles varies the location of feeding the thread 2 to the winded package 4. Such variation is provided in respect of the longitudinal axis of the spindle 6 as well as the orientation of the thread in respect of the circumferential direction when laying the thread 2 upon the winded package. Furthermore, the guiding unit 12 comprises upper rollers 17 for guiding the thread in the region of the traverse mechanism. The guiding unit 12 serves for aligning the thread to an axis 37 by providing axial guidances on both sides independent on the actual angle in the sectional angle 16. Furthermore, lower rollers 18 for guiding the thread are provided. The lower rollers 18 have contact surfaces oriented parallel to the longitudinal axis of spindle 6 and shifted to FIG. 2. These contact surfaces might be used for dividing or fending the thread 2 and/or for guaranteeing that the thread 2 is fed to the pressure roller 19 in a vertical direction in FIG. 2.

Below the guiding unit 12 a pressure roller 19 is rotatably supported. The longitudinal axis of the pressure roller 19 is directed parallel to the longitudinal axis of the spindle 6. Subsequent to the lower rollers for guiding the thread, the thread is passed around the pressure roller 19 over a specific circumferential angle. At the shell or circumference 32 of the winded package 4 the thread comes in contact with the pressure roller 19.

For the shown embodiment, the actuator 20 is built by a pneumatic piston-cylinder-unit activated via a pressure line 21. The actuator 20 builds a hinged pillar 22. The hinged pillar 22 in its end region 23 is pivotably linked with a rod 24 of the housing of the winder 1, wherein the hinged pillar 22 might be pivoted against an axis oriented vertical to the drawing plane of FIG. 1. The opposite end region 37 of the hinged pillar 22 is directly or indirectly linked with the guiding unit 12, here adjacent to the guideway 13. The hinged pillar 22 is inclined against the translational degree of freedom 14 under an angle α. Due to the chosen linking points 33, 34 of the hinged pillar 22, the angle α changes from a starting angle α₁ to an angle α₂ with an increase of the diameter of the winded package 4, wherein α₁>α₂ holds. F_N denotes the normal force of the hinged pillar 22. For the embodiment shown in the figure, the normal force F_N corresponds to the overall force of the actuator 20. The force component F_FHG acting along the translational degree of freedom 14 is determined via

F_FHG=F_N(cos α).

For the aforementioned change of the angle from α₁ to α₂ a change of the force component acting along the translational degree of freedom 14 results as follows:

ΔF_FHG=F_N(cos α₂−cos α₁).

Accordingly, the force component F_FHG acting upon the guiding unit 12 depends on the movement along the translational degree of freedom 14 and from the distance of the pressure roller 19 from the spindle 6 and the diameter of the winded package. The force component F_H acting transverse to the translational degree of freedom results from

F_H=F_N sin α.

Such force component F_H being not effective for the contact force in the shown embodiment is supported by the guideway 13.

For a predetermined movement of the guiding unit 12 along the translational degree of freedom 14, the change of the force ΔF_FHG might be adapted by changing the basic geometry, so by changing the linking points 34, 33 of the hinged pillar 22 with the surrounding components of the winder 1. In case of the working conditions of the winder 1 being in the neighborhood of an angle α=0°, the dependency of the force component F_FHG from the movement of the guiding unit along the translational degree of freedom is minimized. Instead for the opposite theoretical limit case with the angle α being in the neighborhood of 90°, the change of the force component F_FHG is maximized. Suitable geometrics might be chosen between those theoretical limit cases. For providing the possibility of changing the region of used angles, the rod 24 comprises a plurality of linking points 34 for the hinged pillar 22, e.g. a plurality of bores 25.

The actuator 20 is located at the side of the turret head 5 opposite to the spool 3. It is possible that the actuator 20 is covered by a base plate of the winder. As can be seen from FIG. 2, the translational degree of freedom 14 might be inclined in respect of the vertical axis. Without departing from the inventive base principle, it is possible to direct the angle α in any direction in space (differing from the angle α in FIGS. 1 and 3).

FIG. 5 shows a unit 26 for a pressurized fluid for pressurizing the pressure line 21 for the fluid. The unit 23 is equipped with a fluid 27 under an operating pressure. The unit 26 comprises a control valve as well as a switching element 29 that is controlled by a control unit 30 via a control line 31. Via a bypass line 35 in a selected switching state of the switching unit 29 (that is controlled by the control unit 30) the control valve 28 is bypassed and ineffective for completely lifting the pressure roller 19. Alternative embodiments for providing the pressure medium and for controlling the pressure of the pressure medium can be taken from EP 1 213 246.

The winder is in particular designed and used for manufacturing cross-wound packages, wherein the arriving thread is moved by the traverse mechanism along the longitudinal axis of the spool. The winded thread 2 might be made of a fiber, filament or strand carbon material. For the shown embodiment, the angle of the traverse mechanism does not change during the winding process in respect of the arriving thread.

The contact force of the pressure roller 19 with the winded package 4 results from the superposition of the vectors of the weight of the guiding unit 12 with additional components and the component of the force F_FHG of the actuator 20 in the direction of the translational degree of freedom 14. In case of the translational degree of freedom 14 not being oriented in vertical direction, the influence is decreased by the trigonometric function cos of the angle of the translational degree of freedom 14 in respect of the vertical axis.

Many variations and modifications may be made to the preferred embodiments of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention, as defined by the following claims.

Claims

1. Winder for winding a thread or yarn to a winded package comprising

a) at least one spindle,

b) a pressure roller, the distance of said pressure roller from said spindle being dependent on the movement of one element selected from the group consisting of said spindle and said pressure roller along a degree of freedom, said pressure roller being pressed against the outer circumference of said winded package, wherein one element selected from the group consisting of said spindle and said pressure roller being connected to a drive unit for rotating said selected element,

c) wherein said thread or yarn is supplied to said winded package in a contact area between said pressure roller and said winded package,

d) at least one actuator, said actuator being linked with one element selected from the group consisting of said pressure roller and said spindle such that a force produced by said actuator influences the contact force between said pressure roller and said winded package, wherein

e) said actuator is designed, arranged such that it produces a constant force (FN) and

f) at least a component (FFHG) of said force (FN) of said actuator is directed along said degree of freedom and the relation between said component (FFHG) of said force (FN) which is directed along said degree of freedom and said force (FN) of said actuator is dependent on said distance between said spindle and said pressure roller and

g) wherein said degree of freedom is a translational degree of freedom and

h) said actuator influences a normal force (FN) in a hinged pillar, wherein said hinged pillar is inclined with an angle α in respect of said translational degree of freedom, said angle α being dependent on said distance of said spindle from said pressure roller.

2. Winder of claim 1, wherein said actuator is a pressure activated piston-cylinder-unit.

3. Winder of claim 1, wherein the location of at least one hinged linking point of said hinged pillar is designed and arranged to be changed.

4. Winder of claim 2, wherein the location of at least one hinged linking point of said hinged pillar is designed and arranged to be changed.

5. Winder of claim 2, wherein said actuator is a pneumatically activated piston-cylinder-unit.

6. Winder of claim 2, wherein said actuator is controlled by a control unit, wherein said control unit is configured for controlling said actuator for producing a constant force.

7. Winder of claim 5, wherein said pneumatically activated piston-cylinder-unit is pressurized via a control valve providing a constant pressure for said piston-cylinder-unit.