Field of Invention:

The invention relates to a winding apparatus for winding the yam or the slit film tapes that continuously arrive from a feeding apparatus. It also relates to a method for controlling winding tension in a winding apparatus during winding of continuously arriving slit film tape or yam (1). More particularly, it relates to an apparatus and a method for controlling yarn winding tension in a winder system. Even more particularly, it relates to an apparatus for reducing variations or fluctuations in thread tension during winding operations.

Background of Invention:

A yarn winder is used for winding of continuously arriving yarn of polyolefin — flat/fibrillated or any similar type — onto a bobbin. Here, yarn defines flat tapes, multifilament and monofilament yarns or any similar type of yams or tapes. In general, bobbin holders, also known as mandrel cores, are mounted on spindles of each winder head that are in turn assembled on a winder machine frame. Each spindle needs precisely controlled rotation, so may be driven independently by an electric motor through a suitable mechanism such as a belt and pulley arrangement or with a direct driving system. Conventionally, the encoders or other similar devices for pulse generation are mounted on the motor for monitoring the motor revolutions, and the signal therefrom is communicated to the electronic controller with the help of suitable cable. The controller further sends the electrical signals to the inverter/drive of the active motor which determines the power to be given for the motor driving the spindle.

The conventional winders of the above type are widely used. Some of these are disclosed in the US Patent Nos. 5228630, 4765552 and DE 3723593. In winding operations, it is essential that the thread or other material being wound is maintained at a substantially constant tension in order to achieve a uniform product. It is, therefore, necessary to monitor and control thread tension and to make adjustments when the tension varies from some predetermined value. Obviously, it is most desirable to have the monitoring and regulation of thread tension accomplished automatically during the winding process.

In conventional winders, yam winding tension is controlled by regulating tightening of the oscillating arm tensioning spring (hereinafter referred to as a, dancing arm resistance for onwards references). The to and fro motion of dancing arm is monitored electronically to keep yam delivery at nearly uniform tension with constant linear speed to bobbin spindle.

Also in conventional winders, winding tension of yarn is maintained by providing resistance to the motion of the dancing arm by adjusting spring attached to it. Position feedback of dancing arm is routed to the control logic of winders, which in turn rotate the bobbin mandrel (also known as bobbin spindle) such that a position of dancing arm is maintained consistently with least oscillation. To maintain the winding tension for various types of yarn of different properties (such as denier, width etc.), the spring attached to the dancing arm is adjusted such that its variation is minimized as much as possible to achieve good quality of produced bobbins. Conventionally, spring associated with dancing arm is set once at the start of the winding process, which remains constant throughout build of the bobbin as product, however, this is not compatible with the yarn tension which varies with the package size during the unwinding process.

Further, on any given slit film manufacturing machine generally known as tape extrusion lines, there are multiple winders, their numbers ranging from 50 to 500, all working at same linear speed as tape extrusion line. However, it is laborious to precisely adjust each winder head dancer arm spring position and tension, which is conventionally done manually.

The dancer arm is influenced by a spring force or gravitational force, in order to produce a thread tension which must be applied on the other hand over the bobbin spindle during the winding operation by controlling the winding motor speed. This thread tension can be very small or very high in the specific cases. As the bobbin diameter increases, the winding/spindle motor has to be controlled with reducing speed for keeping same linear speed. For this, the winding/spindle motor is provided with a known phase angle control. In order, to control the lowering of speed of the winding motor, the angular position of the dancer arm is used by a correction voltage generator according to the respective angular position. In this case, a center position of the dancer arm of the correction voltage value of zero is assigned, being followed in opposite direction correction voltages to both sides.

This scheme has the disadvantage that for the derivation of the correction voltage, the current angular position of the dancer arm must be detected. A change in angle of the dancer arm is thus a necessary condition for generating the correction voltage and thus the functioning of the control device. At each variation of the angular position of the dancer arm from the central position, the yarn tension changes, depending on the deflection of, the dancer arm spring loading at an angle change of the dancer arm and thus a different spring force is required for different tension values. This has a disadvantageous effect as a given spring will be able to create certain range of spring force which then generates tension for particular linear density (denier) range of yarn being wound. So if there is an increase or decrease in yarn denier beyond the given range then spring has to be changed which is not only laborious but also not feasible.

Another possible problem associated with spring-loaded dancer arms is the fact that the nominal position of the dancer arm tends to be quite different during different phases of the operation of the winder. Even at constant thread tension unwinding during weaving, thus different moments arise depending on the diameter of the bobbin, may cause variation in fabric width.

Even with the pneumatic piston used in place of spring, causes variation in unwinding tension due to friction (stick-slip) effect of pneumatic cylinder and its maintenance.

Further, there is constant increase in demand for winding of sensitive lighter denier yarn material and also, coarser denier yam on same winding system, which makes difficult for conventional tensioning system like spring, due to space constraints and limited range of tension/force.

Thus, there is a requirement for a winding apparatus for overcoming above stated issues of dancer arm on winding machine.

Objects of Invention:

The main objective of the present invention is to provide a winding apparatus/device which has overcome the inherent drawbacks of spring loaded dancer arm yarn tensioning system in winder at one hand and provides a smooth tension mechanism on the other hand.

Another objective of the present invention is to provide a winding apparatus/device which is independent of friction/stick slip effect of conventional pneumatic cylinder.

Yet another objective of the present invention is to provide a compact apparatus/device compact yam tensioning system to overcome space constraint.

Further objective of the present invention is that apparatus/device system is capable of handling lighter to coarser denier yarn. Further objective of the present invention is ease setting of tension on plurality of winder heads through centralized system.

Another objective of this invention is to control winding tension such that there is almost constant unwinding tension in subsequent operation like weaving.

Brief Description Of Figures:

Figure 1 shows a general set-up of a winding apparatus

Figures 2, 2A, 2B, 2C shows the tensioning device of the invention in its various embodiments

Figure 3 shows a schematic of the man machine interface (MMI), parent controller and winder head controllers

Summary Of Invention:

A winding apparatus is disclosed for winding continuously arriving yam (1) or slit film tapes. The invention relates to slit film tape or yam winding type device and a process to control yarn tension during winding. More particularly, it relates to an apparatus and a method for controlling yarn tension using fluidic tension actuator (8) in a winder system. Even more particularly, it relates to an apparatus for reducing variations or fluctuations in yarn tension during winding operations.

The present invention also relates to a winding machine for winding up bobbin with yarn (1) or slit film tape material arriving from a plurality of feeding apparatuses. The winding machine includes a plurality of winding heads/winders each having at least one winding spindle (2), each being designed and arranged to be rotated by a drive. A plurality of traversing apparatuses are designed and arranged to cooperate with one of the winding spindles (2) to wind up the material onto bobbins. The plurality of dancer arms (3) have each provided with a tensioning device, which in turn has at least one tension actuator (8) which serves to determine an instantaneous signal which is approximately proportional to the required tension of the continuously arriving yarn (1).

The winding apparatus of the invention for winding continuously arriving yarn or slit film tapes in a winder system has at least one winder controlled by an individual winder head controller (13) which are controlled by a parent controller (12), a dancing arm (3) associated with each of the winders and provided with a tensioning device, wherein the instantaneous angular position (3F) of said dancing arm (3) is variable during the yarn winding operation, a man machine interface (MMI - 11) interacting with the parent controller (12). The key aspect of the invention is that the tensioning device consists of at least one sealed polymeric fluidic tension actuator (8) which is attached to dancer arm (3) unit with a rotatable mechanism to create required resistance to the movement of the dancer arm (3). A lever (9) and a link (20) are used to connect the tension actuator (8) to the dancer arm (3). The tension actuator (8) generates required resistance on the dancer arm (3) in proportion to the required tension (or winding tension) in the winding yarn. The change in said instantaneous angular position (3F) of said dancer arm (3) is monitored and used to regulate winding tension by changing rotational speed of spindle (2) through the individual winder head controller (13) in required proportion.

Another embodiment of the present invention provides a method for controlling winding tension in a winding apparatus during winding of continuously arriving slit film tape or yam (1) on winder. In particular, a method for controlling winding tension in a slit film tape or yam (1) during its winding process is also disclosed. The method comprises using the apparatus disclosed herein, using which the method determines the winding tension dependent on yarn denier or tape size running on individual winders. The key aspect of the method of invention is that generation of the winding tension is carried out using a sealed polymeric fluidic tension actuator (8), which is controlled either manually or through an electro pneumatic regulator valve (17). List of parts:

Slit film tape/yarn (1) 25 Second end of tension actuator

Spindle with Bobbin (2) (8B)

Dancing Arm (3) Lever (9)

Dancing Arm Rollers (3 A) Third rotatable connection (10) Tensioning device (3B) MMI (ll)

Dancing Arm Movement 30 Parent Controller (12) Delimiter (3C) Winder Head controller (13)

Dancing Arm in optimal operating Pressure line (14) Position (3D) Position sensor (15) Dancing Arm in End Position (3E) Angular arm (16) Dancing arm at instantaneous 35 Electro-pneumatic regulator valve angular position (3F) (17)

Lower end of dancing arm (3G) Pneumatic connector (18) Tensioning Bow (4) Pneumatic pipe/ hose (19) CAM Box (5) Link (20); hole (20A)

Pressure Roller (6) 40 Encoder (21)

Traverse Guide (7) First angle (22)

Tension actuator (8) First rotatable connection (23)

First end of tension actuator (8A) Second rotatable connection (24) Detail Description Of Invention

The general set-up for a winding apparatus is shown figure 1 which includes set of rollers for delivering continuously arriving yam (1) onto the winding spindle mounted with bobbin (2) through the pressure roller (6) mounted with cam box (5) having traverse guide for laying of yarn and dancer arm with roller for regulating the yarn winding tension. In the conventional apparatus for regulating winding tension, a spring based tension setting device (3B) is used for changing the resistance/tension of dancer arm as function of linear density of slit film tape or yarn (1) which is being wound on bobbins (2) to form packages.

Typically, in conventional winders, the resistance of the dancing arm (3) to its oscillating movement during the winding process is controlled by settings of a knob (3B - see figure 1) which can be set at various positions by adjusting torsion of the spring that is provided in the knob, which effectively increases stiffness of the dancing arm (3) system according to yam (1) properties.

In Figures 1, yam (1) is delivered continuously from direction ‘a’ from a feeding apparatus such as stretching and conditioning rollers of a tape line machine. The continuously arriving yarn (1) passes through a dancing arm roller (3 A) onto winding spindle (2) fitted with a bobbin. A winder starts winding as the running yarn (1) passing through dancing arm (3) roller (3 A) causes the dancing arm (3) to assume its instantaneous angular position (3F) due to the yarn tension required for winding. As shown in Figure 1, the position 3E represents the limit of the angular movement of the dancer arm (3)

Also as shown in Figures 1, a to-and-fro traverse assembly or a cam box (5) constitutes a pressure roller (6), a traverse guide (7), and a tensioning bow (4) along with other assembly parts as the arriving yarn (1) it winds onto the bobbin. The yam (1) travels over the tensioning bow (4) before passing through the split film tape traverse guide (7).

The pressure roller (6) presses the spindle (2) to maintain winding tension in the yarn (1). The spindle rotational speed is electronically controlled in a closed loop as per feedback provided on the dancing arm (3) deflection - i.e. information on the instantaneous angular position (3F) of the dancing arm (3) is monitored using a position sensor (16) or an encoder (21), relative to its optimal operating position (3D) during the winding operation) so as to provide optimal winding tension in the yam. The optimal operating position (3D), as the name indicates, is the target position of the dancing arm (3) during the winding operation to achieve optimal package characteristics. However, during the winding operation, depending on the winding process parameters, the dancing arm (3) typically deviates from its optimal operating position (3D). The dancing arm (3) is arranged or designed such that as it is deflected angularly from its optimal operating position (3D) position, the spindle (2) starts rotating and thus yarn winding starts on spindle (2). The extreme positions (3E) which the dancing arm (3) is allowed to assume during a winding operation are facilitated by provision of a dancing arm (3) movement delimiter (3C - not shown).

Typically, in the conventional devices, the setting of the tension setting knob (3B) is not changed during entire winding process. As a part of the closed loop, a position sensor (16) which is mounted on dancing arm (3) regularly transmits details of the instantaneous angular position (3F) of dancing arm (3) to a winder head controller (13) which controls the speed of spindle motor.

During the winding operation on conventional winder with a spring based dancer arm, the machine operator can make a decision regarding manually tightening or loosening of the yarn (1) based on his observation. For instance, if the instantaneous angular position (3F) of the dancing arm (3) is such that the dancing arm (3) deflects from its optimal operating position (3D) towards the winding bobbin (2), then yarn (1) is travelling in a looser-than-desired state. On the other hand, if the dancing arm deflects away from its optimal operating position (3D) in a direction away from the winding bobbin 2), then yarn is traveling in a tighter- than-desired state. According to the instantaneous position (3F) of the dancing arm (3) deflection, positional details of the dancing arm (3) are communicated to the winder head controller (13) and thus the rotational speed of spindle (2) is regulated to control yam tensioning/yarn winding tension.

As stated earlier, a major disadvantage of conventional spring-based dancer tension/resistance setting, are non-consi stent settings of individual winder heads, ultimately resulting in necking or shrinkage of the fabric produced due to varying resultant winding tension, and sometimes in undesired frequent weft breakages.

As an alternative to the fluidic muscle, the tension actuator (8) may be an electric actuator, a hydraulic actuator, a link motion system, and/or so-called “smart materials”, including piezo-electric materials, magnetostrictive and electrostrictive materials, i.e. materials with a capability to change viscosity, e.g. from liquid to almost solid state, shape alloy materials (SMA), thermo-responsive materials and/or conducting polymers.

The tension actuator (8) used in the winding apparatus of the invention for winding continuously arriving yam or slit film tapes is shown in Figures 2, 2 A, 2B, and 2C in its various embodiments. The tension actuator (8) is connected to the dancer arm (3) using a rotatable mechanism.

Specifically, the tension actuator (8) used in the present invention is a fluidic muscle or a sealed polymeric fluidic tension actuator which are also commercially available. In general, a fluidic muscle is a linear member which may be constructed by wrapping a synthetic or natural rubber tube with a woven sheath. This forms an expansible chamber. When a pressurized fluid is applied to the chamber of the fluidic muscle, the chamber expands radially and is accompanied by a corresponding contraction in its length, resulting in linear motion. Metallic or plastic fittings may be secured at both ends to transmit the resultant motion.

The tension actuator (8) is typically a linear element having a first end (8A) and a second end (8B). It is provided with a pneumatic connector (18) at its first end (8A) through which a pneumatic pipe/hose (19) supplies pressure generated by the pressure line (14) which is connected to an electro-pneumatic regulator valve (17).

At its second end (8B), the tension actuator (8) is connected to the lower end (3G) of the dancer arm (3). In order to generate resistance to the movement of the dancer arm, it is important that the connection between the tension actuator (8) and the dancer arm is constructed in a specific manner while allowing the free rotational movement of the connection itself. For this purpose, a lever arm (9) is provided at the second end (8B) of the tension actuator (8) which is connected with a first rotatable connection (23) to a link (20). Both the lever arm (9) and the link (20) are freely rotatable with respect to each other at the end of the link (20) that is close to the lever arm (9). The other end of the link (20) is connected to the lower end (3G) of the dancer arm (3). There is a first angle (22) formed between the link (20) and the lower end (3G) of the dancer arm (3), the value of which is dependent on the design of the winder system. The junction of the link (20) and the lower end (3G) of the dancer arm (3) is rotatable through a second rotatable connection (24) as a unit around a fulcrum or a pivot point. Thus, the junction itself is freely rotatable around a fulcrum point while the first angle (22) between the link and the dancer arm (3) is constant. Because the first angle (22) is constant, the tension generated by the action of the tension actuator (8) is transferred to the dancer arm (3) as resistance to its angular movement. The tension actuator (8) is connected to the winder surface or optionally on the winder frame using a third rotatable connection (10).

The first, second, and third rotatable connections (23, 24, and 10) can be done by any of mechanical joints such as screw-nut arrangement, bush pin arrangement or bearing pin arrangement. In one embodiment, there is multiple tension actuators (8) connected to any single winder head. To facilitate this, there are provided multiple locations on the link (20) where the respective first rotatable connections (23) may be provided. In one embodiment, (see Figures 2B and 2C), the link (20) comprises of multiple holes (20A) which can be provided for the respective first rotatable connections (23). The provision of multiple connection points on the link (20) also allows changing the position of the connection between lever (9) and link (20) from one hole to another for any given tension actuator (8), which permits changing the applied pneumatic pressure, which in turn causes increase or decrease in tension transferred to the dancer arm (3).

The common state of art term for sealed polymeric fluidic tension actuator is “fluidic muscle”, as it is commonly termed (along with pneumatic artificial muscle), is in part the progeny of an invention by Richard Gaylord. Gaylord, in 1955, received U.S. Pat. No. 2,844,126 for a “Fluid Actuated Motor System and Stroking Device.”

In general, a fluidic muscle may be constructed by wrapping a synthetic or natural rubber tube with a woven sheath. This forms an expansible chamber. When a pressurized fluid is applied to the chamber of the fluidic muscle, the chamber expands radially and is accompanied by a corresponding contraction in its length, resulting in linear motion. Metallic or plastic fittings may be secured at both ends to transmit the resultant motion.

In the simplest possible embodiment of the invention, a single fluidic muscle/ sealed polymeric fluidic tension actuator is used to replicate the restoring force provided by the spring.

The sealed polymeric fluidic tension actuator is reinforced resilient bladder having a shape which changes in a predetermined way under variations in its internal pressure. Fluid muscles are available commercially, and may be operated using pressurized air, other gases, or hydraulic fluid.

For the purpose of this disclosure the terms ‘tension actuator’ or ‘sealed polymeric fluidic tension actuator’ (8) will be used interchangeably. A pneumatic hose (19) supplying pneumatic pressure is connected to the tension actuator (8) so as to create required resistance onto the rotational movement of the dancer arm (3) in proportion to the fluidic pressure supplied to said tension actuator (8). The source of pressurized fluid is housed in a reservoir kept at distant location. The generated resistance in turn controls the uniformity of tension applied by the dancer arm (3) on the continuously arriving yam or tape for winding. Any change in the tension of incoming yarn/tape results in swinging of dancer arm (3) to a position depending on difference between arriving yarn tension and required/set winding tension. Thus change in the instantaneous angular position (3F) of dancer arm (3) (indicated by various positions of the dancer arm (3) in Figure 1) - the change being monitored by encoders (21) which can be optical type, magnetic based or other similar device for pulse generation - is communicated to the individual winder’s head controller (13) for changing the motor speed of the spindle (2) in required proportion such that the dancer arm (3) remains in steady condition near the optimal position (3D), thereby maintaining a constant winding tension across the winding system. The steadying of dancer arm (3) at said optimal operational position (3D) is carried out by communicating the data gathered by sensor (15) or the encoder (21) to the individual winder’s head controller (13) on the basis of which the motor speed of the spindle (2) is adjusted.

In another embodiment, a cost effective angular position monitor through position sensor (15) and angular arm (16) can be used for determining instantaneous angular position (3F) of dancer arm (3) which is communicated to the individual winder’s head controller (13). The unique feature of the invention is that generated resistance on dancer arm/winding tension can be controlled through pneumatic/fluidic pressure applied to the tension actuator (8) without any friction or stick slip effect. Also, the tension in more than one winder head can be set through single a control point such as a parent controller (12). Further, as the tension actuator (8) used in the invention does not have any moving part like piston, there no friction effect and at the same time very precise setting of required tension/force can be done. Another, important factor is that sealed polymeric fluidic tension actuator (8) has comparative smaller space requirement than equivalent force pneumatic cylinder used in the conventional winders.

The sealed polymeric fluidic tension actuator (8) is housed on the winder compartment, preferably on back-side. The sealed polymeric fluidic tension actuator (8) is in close proximity of dancer arm (3) such that it can be accessed easily for maintenance purpose.

The first end (8A) of sealed polymeric fluidic tension actuator (8) is connected with winder body surface.

The sealed polymeric fluidic tension actuator (8) can be arranged in required orientation with dancer arm based on the actual yarn path in winder and space availability. The sealed polymeric fluidic tension actuator (8) can be in parallel to dancer arm or can be perpendicular. As shown in figure 2, in one of embodiment, the sealed polymeric fluidic tension actuator (8) is connected below dancer arm

(3)·

In an embodiment, yarn braids are used in polymer tension actuator (8). The dimension of said polymeric tension actuator (8) is directly governed by applied pneumatic pressure which in turn cause increase or decrease in tension transferred to the dancer arm roller (3 A), through a parameter such as the deflection resistance/force of dancer arm (3).

The pneumatic pressure settings of the polymeric tension actuator (8) can be changed manually or automatically through the parent controller (12) according to the required pressure adjustment suitable for proper bobbin/package winding. The pressure settings of the tension actuator (8), which are proportional to the yarn winding tension, depend on yam properties particular yarn denier, thickness, type of yam, required for optimal winding. Preferably, the pressure settings, the package cutoff size, and the final package size, are input using the suitable input interface to system controller prior to starting the winding operation. However, the settings may be adjusted during the winding process, without halting the winding operations.

In fig 3, the functional diagram with preferred embodiments is described. A Man machine interface (MMI) (11) is provided for entering the desired machine/process related parameters of the winder machine (such as yarn, denier, weight, speed, the tube outer diameter), which is known to person skilled in art. The MMI (11), a parent controller (12) and winder head controller (13) communicates with each other either over serial or parallel bus backbone. The parent controller (12) is a channel for data-entering-point into an assembly of such winder units, whereas a winder head controller (13) (or simply a head controller) is a controller for each winder unit. There may be more than one winder unit/head in a winder family.

The parent controller (12) is provided to transfer data to all winder head controllers (13) for their operational requirements and functionality. Parent controller (12) thus transfers process data such as the line speed, winding recipe, etc. from each winder to respective winder head controllers (13) are connected to single ‘parent’ controller (12) (also termed as the ‘gateway’ controller). In one embodiment of the invention, the man machine interface (11) is capable of changing the pressure of supplied fluid to the tension actuator (8) at a pre determined time interval by manual input or inputting pre-programmed values in the parent controller (12) optionally during course of winding operation.

As an illustration, Figure 3 shows a pressure line (14). According to the invention, pressure line (14) from electro- pneumatic regulator valve (17) is connected to the tension actuator (8) of the dancer arm (3) of individual winder unit. The pressure line (14) thus replaces the conventional torsional spring force for adjusting oscillating resistance of the dancing arm (3).

In case of electro-pneumatic regulator valve (17), using the parent controller (12), directly a voltage or current base signal value can be used for precise controlling of applied pneumatic pressure to at least one tension actuator (8).

The invention also discloses a method for controlling winding tension in a winding apparatus during winding of continuously arriving slit film tape or yarn (1). The method uses the apparatus that has been described in detail in the foregoing description. As a part of the method, the winding tension dependent on yarn denier or tape size running on individual winders is determined. The required winding tension is generated using the tension actuator (8) of the sealed polymeric type as described. The value of the pressure supplied to the tension actuator (8) is adjusted centrally using the parent controller (12) to match the winding tension value that has been determined. The method also allows that the pressure supplied to the tension actuator (8) is controlled through the electro-pneumatic regulator valve (17).

The pressure setting of pressure line (14) or pressure at the tension actuator (8) can be changed according to the required pressure adjustment suitable for proper winding through MMI (11). For example, the inventive winder set values can be defined as for denier range 200 - 6000, pressure can varies from 0.5 - 7.5 bar. Thus, said pressure variation changes the dimension of said tension actuator (8) and required resistance is created on dancer arm (3).

In working comparative example (prior art), for the winding of continuously arriving slit film tape yarn of 850 denier at speed of 450 m/min, on conventional winder with spring base dancer arm system, the winding tension was set at around 75 gram. The resultant yarn bobbins showed normal winding shape and during subsequent usage as weft yarn on circular fabric of 500 mm tube, showed width variation along the tube length by ±10 mm.

On the same extrusion line, on other position the inventive winder with sealed polymeric fluidic tension actuator (8) were used for winding of continuously arriving slit film tape yam of 850 denier at speed of 450 m/min, the winding tension was precisely set to around 75 gram. The resultant yarn bobbins showed normal winding shape and during subsequent usage as weft yam on circular fabric of 500 mm tube, showed width variation along the tube length by ±6 mm. The pressure applied was set at 0.8 bars.

Further, on same inventive winder was used for winding of continuously arriving slit film tape yarn of 450 denier at speed of 550 m/min, the winding tension was precisely set to around 25 gram. The resultant yam bobbins showed normal winding shape and during subsequent usage as weft yarn on circular fabric of 500 mm tube, showed width variation along the tube length by ±3 mm.

A person skilled in the art would understand that such reduction in fabric width variation (from ±10mm to ±6mm to ±3 mm) enhances the quality of winding significantly. It is evident from the foregoing discussion that there are a number of embodiments of the invention.

In the preferred embodiment, a winding apparatus for winding continuously arriving yam (1) or slit film tapes is disclosed having at least one winder having a spindle, and controlled by an individual winder head controller (13); a parent controller (12) to control said individual winder head controllers (13); a dancing arm (3) associated with each of said at least one winder and provided with a tensioning device, wherein the instantaneous angular position (3F) of said dancing arm (3) is variable during the yarn winding operation; and a man machine interface (11) interacting with said parent controller (12). The key aspect of this embodiment is that the tensioning device is in the form of at least tension actuator (8) having a first end (8A) and a second end (8B) and which is attached to said dancer arm (3) at its second end (8B) using a rotatable mechanism.

In another embodiment the aforementioned rotatable mechanism is formed by providing a first rotatable connection (23) between a lever (9) provided at said second end (8B) and a link (20), and a second rotatable connection (24) formed between said link (20) and the lower end (3G) of said dancer arm (3).

In a further embodiment, a first angle (22) is formed between said link (20) and the lower end (3G) of said dancer arm (3), said first angle (22) being constant.

In a yet further embodiment, the tension actuator (8) is connected with a third rotatable connection (10) to the winder frame on which said apparatus is mounted.

In a still further embodiment, the first, second, and third rotatable connections (23, 24, and 10) are of the type selected from a group comprising screw-nut arrangement, bush pin arrangement or bearing pin arrangement, or a hinge. In another embodiment, the tension actuator (8) is a fluidic muscle or a sealed polymeric fluidic tension actuator (8).

In still another embodiment, near the first end (8A) of said tension actuator (8), a pneumatic connector (18) is provided to which a pneumatic pipe/ hose (19) is attached to supply pressure from a pneumatic pressure line (14).

In a further embodiment, the tension actuator (8) is configured to generate resistance to rotational movement of said dancer arm (3) in proportion to required winding tension in said arriving yarn (1).

In a still further embodiment, the dancer arm (3) is provided with an angular arm (16) whose instantaneous position is monitored using a positional sensor (15).

In one more embodiment, the instantaneous angular position (3F) of said dancer arm (3) is monitor by an encoder (21) based system mounted on individual winders.

In a further embodiment, the winding tension in more than one winder head is set through a parent controller (12).

In a still further embodiment, the pneumatic pressure applied to said tension actuator (8) through said pressure line (14) is controlled manually or automatically with an electro-pneumatic regulator valve (17).

In another embodiment, the encoder (21) is of a type selected from a group consisting of optical type, magnetic type, or other similar pulse generation type.

In yet another embodiment, the pressure setting of pressure line (14) or pressure at the tension actuator (8) is set through said man machine interface (11). In a still another embodiment, the link (20) has a plurality of locations said lever (9) of any tension actuator (8) is connected to said link (20).

In a further embodiment, at least one hole (20A) is provided on said link (20) where said lever (9) of any tension actuator (8) is connected to said link (20).

In a still further embodiment, the man machine interface (11) is capable of changing the pressure of supplied fluid to the tension actuator (8) at a pre determined time interval by manual input or inputting pre-programmed values in the parent controller (12).

In a yet further embodiment, the number of tension actuators (8) provided on any winder head is more than one.

In one more embodiment, the first rotatable connection (23) is formed at one of said holes (20A) provided in said link (20).

In another embodiment, a method for controlling winding tension in a winding apparatus during winding of continuously arriving slit film tape or yarn (1) on winder is disclosed. It comprised the steps of: a. providing an apparatus as has been disclosed herein; b. determining the winding tension dependent on yam denier or tape size running on individual winders; c. generating said winding tension using said sealed polymeric tension actuator (8); d. centrally adjusting pneumatic pressure value proportionately to said winding tension; and e. optionally controlling the tension actuator pressure through the electro pneumatic regulator valve (17). In another embodiment of the method of invention, the adjustment of pneumatic pressure of step d is made by making dancer arm position steady at optimal operation position (3D) which regulates the rotational speed of said spindle in proportional to the tension generated in the aforementioned step c.

In a further embodiment, the steadying of dancer arm (3) at said optimal operational position (3D) is carried out by communicating the data gathered by sensor (15) or the encoder (21) to the individual winder’s head controller (13) on the basis of which the motor speed of the spindle (2) is adjusted.

In yet another embodiment of the method disclosed here, the pressure the centrally adjusted pneumatic pressure is adjusted without halting the winding operation of said apparatus.

While the above description contains much specificity, these should not be construed as limitation in the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. It must be realized that modifications and variations are possible based on the disclosure given above without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.