Patent Application
20170166414
The present invention relates to automatic turret type winders and more particularly to devices used in transferring of continuous advancing yarn onto empty bobbins during bobbin changeover operations.
In the following description, the term “yarn” is intended to include the threads, tapes, profile tapes, fibrillated tapes and slit-film bands of various linear mass density, diameter, width and thickness. The term ‘yarn’ is also used to describe yarn with multiple threads or ends that a single winder might receive. The term “bobbin” is intended to include any metallic or non-metallic tubes on which the yarn is wound to form a suitable package.
Automatic turret type winders are used in production or take-up process of continuously advancing yarn, for example, in yarn extrusion machines or in rewinding process for making plurality of small size yarn packages from a large yarn package. In general, the turret type automatic winders are positioned side by side in the horizontal direction and stack one above the other in vertical direction. The number of winding positions is exemplary both in horizontal row and vertical row.
The yarn transfer operation is important in the automatic yarn winding operation. If the yarn is not transferred in the first attempt, the continuously advancing yarn gets wasted until it is rethreaded. Worse still, the continuously advancing yarn, if not controlled properly in case it fails to transfer onto the empty bobbin, may interfere with the other yarn winders on the same machine and cause the entire machinery to stop which results in a huge amount of wastage, machine downtime and economic loss. In the worst situations, some parts of the machinery may get damaged.
In automatic turret type winders, a continuously advancing yarn is generally wound on an initially empty bobbin to form a suitable yarn package. When the pre-determined package size (length/diameter/time) is achieved on a bobbin installed on one of the bobbin holders, generally known as a spindle, the continuously advancing yarn is transferred to an empty bobbin installed on another spindle to make a new yarn package. The yarn transfer is carried out by an automatic transfer device and without interrupting the winding operation.
Some of the known devices for transferring the yarn to the grasping device, such as the one disclosed in EP 03725171, involve complex mechanisms. The yarn transfer is achieved by a movement of the entire swivel box that houses the traversing mechanism. This type of movement, which involves the axial displacement of a large mass, requires a complex and expensive device for its execution. Another device, disclosed in the U.S. Pat. No. 8,267,342, uses a mechanical system with special traverse guide mechanism of introducing advancing yarn into a grasping device during the bobbin changeover operation in automatic winder. However, there are a few drawbacks in this system: precision required in the setting of links and limitation in separating yarn from traverse guide and precise, consistency required in re-insertion of yarn back into traverse guide.
One key drawback of prior art systems where the winding operation needs stopping of traverse device during the changeover process is that it reduces the speed and efficiency of the winding operation. The conventional systems that allow yarn transfer without the stoppage of the winding operation are bulky and complex.
There is therefore a need to provide a simple mechanism of achieving the yarn transfer to the catchment area of an empty bobbin followed by returning the yarn to the winding area without stopping the traverse device.
The present invention provides a simple mechanism to achieve the movement of the yarn to the catchment area and to return yarn back into the traverse area without any stoppage of the traverse device.
Accordingly, one object of the invention is to provide a device to shift the advancing yarn from the bobbin traverse area onto to catchment area (or grasping area) of the spindle of an empty bobbin.
A further object of the present invention is to provide a device to return the advancing yarn, from catchment area onto yarn traverse area.
Another object of the present invention is to enable shifting of yarn from the traverse area to the catchment area without separation of yarn from traverse guide.
A further object of the present invention is to allow the yarn shifting from the traverse area to the catchment area without stopping the traverse guide movement.
The present invention is a part of a yarn transfer system used for transferring yarn from a full bobbin to an empty bobbin typically fitted on a winder frame. The invention broadly comprises a yarn traverse device used in transferring a continuously arriving yarn onto an empty bobbin for commencing of winding process during bobbin changeover process in automatic turret winder without any stoppage. This is achieved with the provision of an actuation device that facilitates axial movement of the yarn traverse device. In the present invention, during the bobbin changeover operation, the yarn traverse device is moved axially through the actuation device and allows the traverse guide—while maintaining its normal traverse speed at all times—to move beyond the normal yarn winding zone such that the advancing yarn is within the reach of the yarn grasping device of the ready-to-be-wound empty bobbin. After the yarn transfer is completed, the traverse device moves back to the normal winding zone.
The present invention is a part of a yarn transfer system (1) used for transferring yarn from a full bobbin to an empty bobbin typically fitted on a winder frame (1A). The invention broadly comprises a yarn traversing device (2) (also termed as a yarn traverse device or simply a traverse device) used in transferring a continuously arriving yarn (or simply yarn) (3) onto an empty bobbin (4) for commencing of winding process during bobbin changeover process in automatic turret winder without any stoppage. This is achieved with the provision of an actuation device (5) that facilitates axial movement of the yarn traverse device (2).
The conventional automated turret type yarn winders have a traverse mechanism for laying yarn along the length of spindle on which the yarn gets wound, generally with help of a traverse guide. They also have a system with which the spindles shift into and away from winding positions, and rotate during the winding operation, and a system to transfer yarn onto an empty bobbin during changeover from full bobbin to the empty bobbin. In winder systems, the traverse mechanism lays yarn linearly onto the bobbin throughout the normal running conditions, which represents the winding operation. During the bobbin-changeover stage, the traverse guide (7), which is a part of the traverse device (2), typically positions itself at the end of its own movement span and helps the advancing yarn (3) to get grasped into a grasping device (14) of an empty bobbin (4). The traverse mechanisms would be selected from cross spiral shaft type mechanisms, or a groove drum or stepper motor-belt type mechanisms, or other known mechanisms depending on requirement.
All conventional yarn transfer systems require the traverse guide to come to a momentary standstill at the time of bobbin changeover.
The present invention, however, provides an improved turret type automated yarn winder, wherein provided is a yarn traversing device (2) which incorporates an actuation device (5), in aiding transfer of the arriving yarn (3) onto an empty bobbin (4) during a bobbin changeover process without requiring the traverse guide (7) to come to a halt. The traverse guide (7) thus operates at its normal operating speed at all times. The normal operating speed of the traverse guide (7) is controlled by an electronic control device not shown in figures. The yarn transfer system (1) is adapted to be compatible with depending on the traverse device (2) employed.
In the present invention, during the bobbin changeover operation, the yarn traverse device (2) is moved axially through an actuation device (5) and allows the traverse guide (7)—while maintaining its normal traverse speed—to move beyond the normal yarn winding zone (6) such that the advancing yarn (3) is within the reach of the yarn grasping device (14) of the ready-to-be-wound empty bobbin (4). Regardless of the type of traverse mechanism employed, the yarn transfer device (1) of the invention allows the axial movement.
The yarn transfer system along with the present invention is now illustrated.
The actuation device (5) is powered by various modes of energy such as pneumatic or hydraulic pressure, electricity or their combination. A traverse housing (13) encloses the traverse device (2), actuation device (5), and some other standard operating assemblies used in the yarn winder.
The cross-spiraled shaft (11) (as shown in
It is important to note that the during normal yarn winding (yarn-laying) in the conventional yarn winding apparatuses, the traverse guide (7) traverses within the zone termed as the winding zone (6). During the winding operation, it is important that the traverse guide (7) does not travel beyond the limits of the winding zone (6) as otherwise it will destroy the consistency of winding of the arriving yarn (3) over the winding bobbin (9) and the finished package will be of non-uniform thickness over its winding zone (6).
At the same time, once the winding operation is complete, the arriving yarn (3) needs to be transferred to an empty bobbin (4). To achieve this, the arriving yarn (3) needs to be positioned near the yarn grasping devise (14) of the empty bobbin (4). For this purpose, the traverse guide (7) needs to move out of the winding zone (6) and into the zone or area termed as the catchment area (16) (indicated in
The bobbin tube is driven by and supported on a winding spindle (driving of spindle has not been shown in the figures). During the winding operation, an empty bobbin (4), which constitutes a second winding spindle with an empty tube supported thereon, is provided in a standby position (see
When the pre-determine size (length/weight/time) of package is achieved (see
Further, without stopping the normal movement of the traverse guide (7), the cam box (10), and consequently the cross-spiraled shaft (11) of the yarn traversing device (2), is internally (i.e. completely inside the traverse housing (13)) axially shifted by the actuation device (5) such that the arriving yarn's (3) ‘transfer point’ (a point from where the arriving yarn (3) is transferred by the traverse guide (7) to the grasping device (14)) is positioned within the catchment area (16) (also termed as the grasping area). This is seen from
During the bobbin changeover operation, the turret (8) would rotate around its axis, with or without any swivel (or backward) movement of the traverse housing (13). Then, as soon as the spindle of the empty bobbin (4) is placed at the winding position, the cross-spiraled shaft (11) of the traverse device (2) is pneumatically shifted in forward axial direction (See
Simultaneously with the severance of the arriving yarn (3), the cross-spiral shaft (11) is pneumatically (or by any other means) retracted back axially (reverse axial movement) to normal traverse zone or winding zone (6) of the empty bobbin (4), and normal winding of continuously arriving yarn (3) resumes (see
The internal axial shifting of traverse device (2) is achieved using the actuation device (5). The working of the actuation device (5) is shown in
The invention thus ensures that the cam box (10) moves or slides axially forward and backward completely inside the traverse housing (13).
Inside the dual acting actuating cylinder (17), the first pressure chamber (19) and the second pressure chamber (20) are formed on either side of the piston rod (18) (see
To facilitate the forward movement of the piston rod (18), the second inlet (22) acts as an air intake(or a fluid intake as fluid of any type in general may be used) leading to a pressure build-up in the second pressure chamber (20), and a simultaneous pressure relief in the first pressure chamber (19). The simultaneous pressure relief and pressure build-up pushes the piston rod (18) in the forward direction. Once the yarn transfer operation is complete, the piston rod (18) moves back in a direction towards the turret plate (8). To facilitate this, the first inlet (21) now acts as a fluid intake and the second inlet (22) as the exhaust port, leading to a pressure build-up in the first pressure chamber (19), and a simultaneous pressure relief in the second pressure chamber (20). The piston rod (18) thus returns to its normal running condition position. The actuating piston rod (18) is thus reciprocally moved by alternatively supplying air (or any suitable fluid) into the pressure chambers (19, 20) formed on either side of the piston rod (18).
An electro-mechanical control system may be used to govern the activation of actuation device base on signal from controller.
The actuation device (5) may be located non-axially with the cam box (10), or the cross-spiraled shaft (11), or traverse device (2) as a whole. In this case, the actuation force (the force required to cause the axial movement of the cross-spiraled shaft (11) or the cam box (10)) is transferred to the cross-spiraled shaft (11) using a link mechanism.
In another embodiment, the axial movement of said traverse device (2) is facilitated using a hydraulic system, or a magnetic solenoid type actuator with a return spring, or a rack-pinion system and an electric motor. In the case of any axial movement facilitated by fluids, the movement is aided by the pressure build-up and relief as explained earlier. There are other alternative mechanisms, such as magnetic solenoid based system or mechanical systems involving return springs or rack or pinions, or electric systems, to effect linear axial movement of the traverse device (2). In these alternative mechanisms, there's no need for a double acting actuating cylinder (17).
In the present inventive method, as there is only axial shifting of traverse guide (7) out of the winding zone (i.e. the zone covered by the yarn during traversing), the advancing yarn (3) remains intact and engaged in the traverse guide (7) of any given design during the bobbin changeover operation. Further, as the yarn transfer method involves only fluid pressure, there are no complicated mechanical linkages or parts involved and the response is quick, accurate and consistent.
Thus, with present inventive method and device, the bobbin changeover with advancing yarn (3) is achieved without stoppage of the movement of the traversing guide (7) and also by keeping the advancing yarn (3) intact and engaged, at all times, with the yarn traverse guide (7).
The swivel movement of the traverse housing (13) during the yarn transfer process is viewed as an additional and undesirable step—it not only adds to the time of bobbin changeover operation but it also undesirably affects the consistency of the winding (particularly in the context of yarn tension).
In another embodiment of the invention, the swivel movement of the traverse housing (13) at the time of the bobbin changeover is eliminated, in the case where the package diameter is equal to or greater than a pre-decided value. The swivel action is generally necessitated by the fact that a pressure roller (13A) (also termed as contact roller; not shown in figures) and the traverse housing (13), which lean on the winding bobbin (9), obstruct the rotational movement of the turret (8) which is required to bring the empty bobbin (4) into the winding position. Then, as soon as the empty bobbin (4) spindle is placed at winding position, the cross-spiral shaft (11) is pneumatically shifted in axial direction such that the advancing yarn (3) comes onto the catchment area (16). With the rotation of spindle the yarn grasping device (14) mounted on spindle would catch the yarn (13) in its grasping element and the yarn (3) gets severed from the winding bobbin (9) mounted on other spindle. Simultaneously, the cross-spiral shaft (11) is retracted back to normal traverse zone, pneumatically, and normal winding of continuously arriving yarn (3) takes place.
In another embodiment, the entire axial movement of the cam box (10) occurs inside the traverse housing (13).
Based on the foregoing discussion, it is evident that the invention has the following embodiments:
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 3253/DEL/2013 | Feb 2014 | IN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2015/050776 | 2/2/2015 | WO | 00 |
