A PRECISION WINDING APPARATUS
FIELD OF THE INVENTION
[0001] This invention relates generally to devices for winding continuous textile material into a bobbin package, and more particularly to a precision winding apparatus for forming a cross-wound bobbin yarn package.
BACKGROUND ART
[0002] In general, a precision winding apparatus uses a yarn traverse mechanism comprising a grooved drum with a yarn guide for facilitating production of a cross-wound yarn package. A cross-wound bobbin package is placed on a free rotatable bobbin chuck and the thread to be wound along the bobbin package surface is traversed by means of the yarn guide in the grooved drum.
[0003] One such precision winding apparatus is disclosed in US Patent No. 3615060 titled the method and apparatus for winding endless yarn fed at a constant speed onto a spool driven at its circumference by a drive cylinder and assigned to Maschinenfabrik Schweitzer AG, Switzerland. Accordingly, the thread is fed to the spool via a grooved drum. The drive cylinder is driven in known manner at a constant speed. Yet, the grooved drum itself is driven in dependence upon and as a function of the number of rotations of the yarn spool or the diameter of the yarn spool and thus a constant winding ratio is maintained.
[0004] Another winding device is disclosed in United States Patent No. 4049211 assigned to Rieter Machine Works Ltd., Switzerland. Accordingly, the winding apparatus for textile threads comprises a helical grooved shaft for moving the thread guide traversely in drive relation with bobbin chuck to form a cross wound bobbin package, wherein by using an electronic control unit, the rotational speed of frictional drive drum, speed of thread and rotational speed of helical grooved shaft are calculated and controlled in order to maintain a constant winding ratio
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throughout the winding process.
[0005] In the above conventional precision winding apparatus, two separate motors are used for driving the package and the traverse mechanism and the driving is synchronized by means of tachogenerators. In order to maintain a constant winding ratio between the package and the traverse mechanism, an electronic control unit/PLC with higher configuration is normally used.
[0006] The above prior art precision winding apparatuses possesses the following disadvantages:
(i) Chances of pattern formation due to use of grooved drum for traversing the yarn.
(ii) Use of two separate motors, Tachogenerators and electronic control unit/PLC leads to increase the cost the equipment.
(iii) Difficult to maintain constant wind ratio and therefore variation in wind ratio leads to formation of pattern.
SUMMARY OF THE INVENTION
[0007] In an embodiment, a precision winding apparatus comprises a winding unit and a traversing unit. A means is provided for driving the winding unit. The winding unit is in turn configured to drive the traversing unit wherein the winding ratio is maintained constant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a isometric view of the precision winding apparatus according to an embodiment of this invention.
[0009] FIG. 2 shows the front view of the precision winding apparatus according to an embodiment of this invention
[0010] FIG. 3 shows a side view of the precision winding apparatus according to an embodiment of this invention.
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[0011] FIG. 4 shows a isometric view of yarn traversing arrangement of the precision winding apparatus according to an embodiment of this invention.
DESCRIPTION OF THE INVENTION
[0012] Various embodiments of this invention provide a precision winding apparatus for forming a cross-wound bobbin yarn package.
[0013] Fig. 1 Fig. 2 and Fig.3 show the isometric, front and side views of the precision winding apparatus according to an embodiment of this invention. Accordingly the precision winding apparatus (100) comprises a winding unit (110) and a traversing unit (120). The traversing unit (120) is mounted on a cage (9) as seen in Fig. 1. Amotor(1)is provided to drive the winding unit (110). The winding unit (110) is mechanically coupled to the traversing unit (120). As the motor (1) is operated to drive the winding unit (110), the winding unit (110) winds the continuous material (not shown in fig.) into cross-wound package (3). As the winding unit (110) is mechanically coupled to the traversing unit (120), the winding unit (110) during winding also drives the traversing unit (120). The traversing unit (120) traverses the continuous material such that the winding unit (110) produces a cross-wound package (3).
[0014] In an embodiment other known driving sources such as an IC engine may be used for driving the winding unit instead of the motor (1).
[0015] Various embodiments of the winding unit (110), traversing unit (120) and the driving mechanisms will be described in detail in the further part of this description.
[0016] Referring to Fig. 1 ,Fig. 2 and ,Fig. 3 the winding unit (110) comprises a spool (7) mounted on a spool axis (7a). A friction roller (2) is disposed in substantial contact relationship with the spool (7). The friction roller (2) is mounted on an axis (2a) (hereinafter referred to as friction roller axis), which is aligned substantially parallel to the spool axis (7a).
[0017] The friction roller (2) is configured to maintain a predetermined contact pressure with the cross-wound package (3) as the continuous material is wound on the spool (7). In some examples, a pneumatic device such as a pneumatic
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cylinder, a mechanical device such as spring means may used to provide such predetermined contact pressure. It should be noted that the pressure is predetermined to produce a compact package without lose windings. It will be obvious to a person skilled in the art to set and vary the contact pressure is according to the growing diameter of the package.
[0018] In an embodiment a first transmission means (130) is provided for driving the winding unit (110) using the motor (1). In an example the first transmission means (130) is a belt and pulley transmission. Other examples may include a gear drive or any other known transmission mechanisms depending upon the machine assembly layout and related requirements.
[0019] In an embodiment shown in Fig. 1 ,2 and 3 the first transmission means (130) comprises a first belt and pulley arrangement (SI) having pulley (PI) coupled to the friction roller axis (2a) and a second Pulley (P2) coupled to the motor (1). A first transmission belt (B1) is provided to couple the Pulleys (PI), (P2) such that the drive from the motor is transmitted to the friction roller (2) through the belt (B1) and in turn the friction roller (2) drives the spool (7) for winding the continuous material.
[0020] It should be noted that the speed (Ns) of rotation of the motor (1) and in turn the speed of rotation (Ns) of the spool (7) is dependent on the delivery speed at which the continuous material is supplied. It should be noted that during the process of build up of the cross-wound package (3), the diameter of cross-wound package (3) increases while the package winding speed (Ns) decreases with respect to the diameter ratios of the friction roller (2) and cross-wound package (3).
[0021] In an embodiment the traversing unit (120) comprises a pair of discs (10, 10'). The disc (10) is mounted on a hollow shaft (11) which is rigidly and coaxially fitted to an upper bevel gear (G1). A shaft (12) is rigidly and coaxially fitted to a lower bevel gear (G3). The shaft (12) passes through the hollow shaft (11) and the disc (10') is rigidly fitted to the hollow shaft (12). When the traversing unit (120) is driven, the discs (10 , 10') rotate in opposite direction to each other and the continuous material such as yarn passing through the disc
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(10, 10') traverses along the length of the spool (7) to form a cross wound package (3) of continuous material.
[0022] In an embodiment the second transmission means (140) comprises at least one of a belt and pulley transmission, a gear transmission and a combination thereof. In the embodiment shown in Fig. 1-3, the second transmission means (140) comprises a second belt and pulley arrangement (S2) coupled to the spool axis (7a) and a gear arrangement (G) coupled to the traversing unit (120), and a third belt and pulley arrangement (S3) coupling the second belt and pulley arrangement (82) and the gear arrangement (G). This arrangement is clearly seen in Fig. 2.
[0023] In an example the second belt-pulley arrangement (S2) comprises a pulley (P3) and a pulley (P4) wherein a belt (B2) couples Pulleys (P3), (P4). The third belt and pulley arrangement (S3) comprises a pulley (P5) and Pulley (P6) wherein a belt (B3) couples the pulleys (P5) and (P6).
[0024] In an example, the gear arrangement (G) comprises a pair of vertical bevel gears (G1) and (G3) coupled to the discs (10,10') and a Bevel gear (G2) coupled to pulley (P6) of the third belt and pulley arrangement (S3).
[0025] Fig. 4 shows the drive transmission flow diagram of the precision winding apparatus according to an embodiment of this invention. Accordingly the motor (1) drives the friction roller (2) through the first transmission means (S1). The friction roller (2) drives the spool (7) and the cross wound package (3) is built. The spool (7) or the cross wound package (3) drives the traversing unit through the second transmission means (140) comprising a second belt and pulley arrangement (S2), third belt and pulley arrangement (S3) and the gear arrangement (G).
[0026] It should be noted that during winding the diameter of the package (3) increases and as a result the speed of the spool (Ns) decreases relative to the friction roller. Since, the winding unit (110) is mechanically coupled to drive the traversing unit (120) even as the speed (Ns) of the spool (7) decreases ,the speed (Nd) of the discs varies accordingly thereby maintaining a constant winding ratio. Due to the direct mechanical coupling of the winding unit and the
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traversing unit, the winding ratio not only remains constant during the entire winding process, the number of windings is also maintained constant.
[0027] It should be noted that although the embodiment shown in Fig. 1 Fig. 2 and Fig. 3 show the second transmission means (140) comprising a second belt and pulley arrangement (S2), third belt and pulley arrangement (S3) and the gear arrangement (G), the number and type of transmission arrangements can be altered depending upon the machine assembly and layout requirements.
[0028] Thus according to the principles of this invention the winding unit (110) directly drives the traversing unit (120) and therefore the drive synchronization can be achieved to maintain a constant wind ratio. Furthermore, the motor can be driven at constant speed for a particular delivery of the continuous material and therefore the entire process of winding control can be significantly simplified. Moreover, since only one motor is used, expensive electronic circuits/PLC and the like required for drive synchronization are not required and the cost per drum for the winding machine according to the principles of this invention can be significantly reduced.
[0029] Various embodiments of this invention provide a precision winding apparatus for a continuous material, such as yarn. The embodiments are not limited and can be implemented with modifications that are obvious to a person skilled in the art. However, such modifications are deemed to be within the scope of the claims claimed herein under:

We Claim;
1. A precision winding apparatus, comprising:
(i) a winding unit having a spool for winding an endless material to
form a cross-wound package; (ii) a traversing unit having discs for traversing the endless material
during winding; (ili) a motor means for rotatably driving the spool and/or cross
wound package through a first transmission means; and (iv) a second transmission means for receiving the drive from the
spool and/or cross wound package and transferring the
received drive to the traversing discs.
2. A precision winding apparatus as claimed in claim 1 wherein the winding unit comprises a friction roller in substantial surface contact relationship with the spool wherein the motor means is rotatably coupled to the friction roller through the first transmission means.
3. A precision winding apparatus as claimed in claim 1 wherein the first transmission means comprises at least one first pulley coupled to the motor, at least one second pulley coupled to the friction roller, and a first belt coupled to the first and the second pulleys.
4. A precision winding apparatus as claimed in claim 1 wherein the second transmission means comprises at least one of a belt and pulley transmission, a gear transmission and a combination thereof.
5. A precision winding apparatus as claimed in claim 4 wherein the second transmission means comprises at least one belt and pulley transmission coupled to the spool and at least one gear transmission coupled to the discs.
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6. A precision winding apparatus as claimed in claim 1 wherein the
traversing unit is synchronously coupled with cross-wound package drive
to maintain constant winding ratio.
7. A precision winding apparatus, comprising:
(i) a winding unit;
(ii) a traversing unit:
(iii) a means for driving the winding unit;
(iv) the winding unit configured to drive the traversing unit wherein the winding ratio is constant.
8. A precision winding apparatus as claimed in claim 9 wherein the means
for driving the winding unit is a motor.