SA YARN TRAVERSING ASSEMBLY FOR A PRECISION WINDING
APPARATUS
FIELD OF THE INVENTION
[0001] This invention relates generally to devices for winding continuous textile threads into a bobbin package, and more particularly to a Yarn traversing assembly for a precision winding apparatus for forming a cross-wound bobbin yarn package.
BACKGROUND ART
[0002] Conventional precision winding apparatus uses a traverse mechanism consisting of a regulating drive motor, which drives the yarn guide blades. This yarn guide blades/propellers/rotors are used to traverse the yarn along the length of yarn package while yarn winding operation. A yarn traversing arrangement is disclosed in US Patent No.6109558 by Barmag AG wherein a yarn traversing apparatus is provided for reciprocating a running yarn to form a wound yarn package, and wherein the yarn is reciprocated by sequential contact with oppositely rotating rotator blades. The blades can each be driven at a variable rotational speed, so that irrespective of the position of the yarn radially along the length of the rotator blades, the traversing speed of the yarn can be controlled so as to follow a predetermined traversing speed profile, which may be constant or variable. This arrangement uses two separate motors for driving each blade individually. Further a control circuit is required to synchronize the traversing speed with the winding speed.
[0003] Another known arrangement disclosed in United States Patent No. US4646983 by Barmag Barmer Machinenfabrik includes a spur gear drive assembly and eccentric bushing, to transmit the power to the corresponding transmission shaft of the yarn guide rotors. Since there is a backlash between the gears of the drive, a special tool is required to adjust the eccentric bushings for the purpose of avoiding the backlash. This adjustment is done at initial stage. After these adjustments, the traversing assembly operates free of play or backlash. And in some cases, a crossed belt drive system can also be used to

achieve the counter rotation of the blades/rotors. However, this arrangement does not provide sufficient control over the yarn tension, which affects the uniformity of the density of the yarn package, which may lead to improper dyeing and slough-off while unwinding.
[0004] Thus the above disclosed prior art has the following disadvantages:
1. Chances for backlash in the drive assembly.
2. Requires special tool to avoid backlash between the gears at initial stage.
3. Does not provide sufficient control over the uniformity of the density of yarn package.
4. Counter rotation of the blades/rotors need eccentrics and hence the system is a complicated.
5. More number of components such as two motors and control unit are required which in turn makes the system costlier.
SUMMARY OF THE INVENTION
[0005] In an embodiment, a yarn traverse assembly for a precision winding apparatus, comprises at least one yarn traversing unit and at least one drive unit coupled to the yarn traversing unit and accommodated in a cage. The drive unit comprises at least one drive shaft comprising at least one drive gear coupled to a drive source. At least one first driven shaft having at least one first driven gear is configured in meshing relationship with the drive gear. At least one second driven shaft having at least one second driven gear is configured in meshing relationship with the drive gear. The first and the second driven shafts are configured in co-axial relationship with each other and supported on the cage. The yarn-traversing unit comprises at least one first blade member coupled to the first driven shaft and at least one second blade member coupled to the second driven shaft. During operation of the drive unit, when the drive shaft rotates, the first and the second driven shafts rotates in mutually opposite directions, thereby rotating the coupled first and second blade members in mutually opposite directions for traversing the yarn for package formation.

BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows the isometric view of a yarn traverse assembly for a precision winding apparatus according to an embodiment of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0007] Various embodiments of this invention provide a yarn traverse assembly for a precision winding apparatus. However the embodiments are not limited and may be implemented in connection with traversing of any continuous material such as wires, plastics etc.
[0008] Fig. 1 shows the isometric view of a yarn traverse apparatus according to an embodiment of this invention. Accordingly, the yarn traverse apparatus comprises; a first means (10) for traversing a yarn. A drive means (20) is provided for driving the first means (10). The drive means (20) comprises a plurality of bevel gears (3,4) coupled to the first means (10), for driving the first means (10). A second means (30) is provided for driving the bevel gears (3,4).
[0009] In an embodiment shown in Fig. 1, a bevel gear (2) is provided meshing with the bevel gears (3,4) for driving the bevel gears (3,4).
[0010] In an embodiment, the bevel gear (2) may be driven by a motor (not shown).
[0011] Other embodiments may include a precision winding apparatus having a winding unit thereon. In such case, the bevel gear (2) may be driven by the winding unit through a transmission such as belt and pulley transmission. In this case, the traversing speed is synchronized to the winding speed.
[0012] In an embodiment shown in Fig. 1, the first means (10) comprises at least one yarn-traversing unit having a first blade member (6), and a second blade member (6'). The drive means (20) includes at least one drive unit having a drive shaft (201). The bevel gear (2) is mounted on the drive shaft (201). Both the drive shaft (201) and the bevel gear (2) may be mounted using bearings within a cage (1). The bevel gear (3) is mounted on a first driven shaft (5a) and

supported on the cage (1) through a bearing. The first driven shaft (5a) could be a hollow or solid shaft. The fist blade member (6) is mounted rigidly on the first driven shaft (5a).
[0013] In an example the first blade member (6) may be rigidly screwed on to the first driven shaft (5a). Other conventional method may also be used as long as the first blade member (6) rotates integrally with the first driven shaft (5a) wherein the rotation of the first blade member (6) provide for traversal of the continuous material along first direction for package formation by the winding unit of the precision winding machine.
[0014] A second driven shaft (5) is mounted to the cage (1) and the bevel gear
(4) is mounted to one end of the second driven shaft (5). A second blade
member (6') is mounted to the second driven shaft (5). It should be noted that in
the embodiment shown, the second driven shaft (5) is hollow and the first driven
shaft (5a) is coaxial and internal to the second driven shaft .(5) The mounting of
the second blade member (6') over the second driven shaft (5) may be done by
rigidly screwing the second blade member (6') onto the end opposite to that of
the bevel gear
(4). However other conventional methods can be used to ensure that the second
blade member (6') rotates integrally with the second driven shaft (5) and such
rotation of the second blade member (6') causes traversal of the continuous
material in a second direction for package formation.
[0015] When a separate motor or the drive source from the winding unit is used to drive the drive shaft (201), the bevel gear (2) mounted to the drive shaft (201) rotates along with. Since the crown gear (2) is in meshing relationship with the bevel gears (3,4) as shown in Fig. 1 the first and the second driven shafts (5a),
(5) rotate along with the bevel gears (3,4). However in an arrangement shown in
Fig. 1, the first driven shaft (5a) rotates in a direction opposite to the rotation of
the second driven shaft (5). Therefore, the first and the second blade members
(6, 6') respectively attached to the first and the second driven shafts (5a, 5)
rotate in mutually opposite directions for traversing the continuous material such
as yarn for package formation.

[0016] It should be noted that a single drive is required for driving the crown gear (2) and thereby driving the bevel gears (3, 4) for rotating the first and the second blade members (6, 6') in mutually opposite direction for yarn traversal. Since in the arrangement proposed it is possible that the drive can be sourced from the winding unit, there is no need for use of two separate motors, and the winding speed and the traversing speed can be synchronized without use of much complicated control systems.
[0017] 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:

claim:
1. A yarn traversing assembly for a precision winding apparatus, comprising: (i) at least one yarn traversing unit; (ii) at least one drive unit coupled to the yarn traversing unit; (iii) said drive unit, comprising:
(a) a drive shaft comprising one drive gear coupled to a drive source;
(b) one first driven shaft having one first driven gear configured in meshing relationship with the drive gear;
(c) one second driven shaft having one second driven gear configured in meshing relationship with the drive gear;
(d) said first and the second driven shafts configured in co¬
axial relationship with each other.
2. A yarn traversing assembly as claimed in claim 1 wherein the first and the second driven shafts are mounted with first and second blades members that rotate in mutually opposite direction.
3. A yarn traversing assembly as claimed in claim 1 wherein the drive gear is a bevel gear.
4. A yarn traversing assembly as claimed in claim 1 wherein the apparatus comprises a yarn winding unit and the drive source is mechanically coupled to yarn winding unit.
5. A yarn traversing assembly as claimed in claim 1 wherein the driven gear is a bevel gear.
6. A yarn traversing assembly as claimed in claim 1 wherein the second
drivenshaft is hollow.
7. A yarn traversing assembly for a precision winding apparatus, comprising:
a) a first means for traversing a yarn; and
b) a drive means for driving the first means;
c) said drive means comprising a plurality of bevel gears coupled to

the first means; and d) a second means for driving the bevel gears.
8. A yarn traversing assembly as claimed in claim 7 wherein the second means is a motor.