DESC:F O R M 2
THE PATENTS ACT, 1970
(39 of 1970)
The Patent Rule, 2003

COMPLETE SPECIFICATION
(See section 10 and rule 13)
“NIPPER DRIVE ARRANGEMENT FOR A TEXTILE COMBING MACHINE”
BY
LAKSHMI MACHINE WORKS LIMITED
AN INDIAN COMPANY
PERIANAICKENPALAYAM, COIMBATORE – 641020,
TAMILNADU, INDIA

The following specification particularly describes the invention and the manner in which it is to be performed
FIELD OF THE INVENTION
The present invention relates to a drive arrangement for the textile spinning preparatory machines. In particular the invention relates to a top nipper drive arrangement for a textile combing machines.
BACKGROUND OF THE INVENTION
Textile spinning preparatory combing machine comprises a plurality of combing heads. In general, there would be eight combing heads. Each combing head has a nipper unit, a circular comb and a pair of detaching rollers. Said nipper unit have two swinging plates, top nipper plate and bottom nipper plate both plates are moved relatively to close and clamp the fibers while combing which are moved for a predetermined length by each feed before combing sufficiently while detaching. The circular comb combs the end of the fiber lap and the combed web is moved towards the pair of detaching rollers by forward movement of the nipper unit. In accordance with the forward movement of the web, the pair of detaching rollers is rotated in reverse direction to move back the previously drawn web. Thus, the rear end of the previous web and the front end of newly combed web are overlapped. When the pair of detaching rollers is rotated in forward direction, the web is drawn from the nipper unit and the rear end of the said web is combed by the top comb which pierces in the web. While such operation is repeated, the web fed by the respective combing heads are bundled and drafted. Calendar rollers compress the bundled and drafted web thereby to form combed sliver.

The speed of the combing machines are measured by number of nipping motions done per minute, said combing machine speed are in the range of 500 to 600 nips/min. Whenever the machine operated beyond this speed, the combing quality deteriorates because of high combing velocity, imperfect piecing in detaching rollers and mechanical vibrations of the machine. Above said causes are primarily related to the bottom nipper, top nipper, detaching roller displacement, velocity and accelerations. These effects can be reduced when all the nipper part movements are kept as minimum as possible. Reducing nipper movement for operating at higher speed will require precise timing of desired opening and closing in nipper mechanism. But with the existing mechanisms, while reducing the bottom nipper shaft motion, precise timing of desired opening and closing of bottom and top nipper cannot be achieved with the existing mechanism.
In the known arrangement, as nipper movement is more to achieve the nipper closing and opening, the bottom nipper shaft and top nipper shaft are oscillated in same direction. If the nipper movement is small, this oscillation of same direction will not give desired opening and closing timings in nipper mechanism. Even though if these shafts are rotated in opposite direction by using gear drive, the angular displacements are proportionate with constant ratio and therefore nipper opening and closing timing cannot be achieved with the proper feed roller movement.
OBJECTIVE OF THE INVENTION
These objectives are provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This objective are not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
An important object of the invention aims at providing a compact solution for the shortcomings of the above-mentioned mechanisms.
Another main object of the invention is to provide a top nipper drive arrangement, which provides gripping for perfect combing and releasing of the fibers at precise time intervals for optimum piecing of fibers at the detaching rollers and reduced machine vibrations even operated beyond 600nips/min.
Yet another object of the invention is to provide the desired angular velocity to top nipper drive from the oscillating nipper shaft.
Further object of the invention is to provide the desired angular velocity of top and bottom nipper shafts during opening and closing of nipper shaft from top nipper drive.
SUMMARY OF THE INVENTION
According to an aspect of the invention, a nipper drive arrangement for a textile combing machine adapted to drive the top nipper shaft of a combing machine comprising at least an anti-parallelogram linkage mechanism.
According to another aspect of the present invention, the anti-parallelogram linkage mechanism comprises a nipper crank, a coupler link, a top nipper connecting link and a virtual linkage – I (VI).
According to yet another aspect of the invention, the nipper crank having a first nipper crank end and a second nipper crank end, coupled to the nipper drive shaft at the first nipper crank end, and the second nipper crank end is pivotally connected to the first end of the coupler link at a first pivotal point (P1). The top nipper connecting link having a first end and a second end, wherein the first end of the top nipper connecting link is connected to the second end of the said coupler link at a second pivotal point (P2) and coupled to the top nipper shaft through the second end of the top nipper connecting link. A flexible link having a first end and a second end connected to the top nipper shaft through its first end at third pivotal point (P3) and to the top nipper plate at the second end of the flexible link at pivotal point (P4).
In a further aspect of the invention, the drive arrangement further comprising a bottom nipper plate coupled to the nipper shaft and to a circular comb shaft, wherein the bottom nipper plate is coupled to the nipper shaft through a linkage, and a rocking lever, whereas the bottom nipper plate is coupled to the circular comb shaft through a connecting lever; and an additional link having a first end and a second end, wherein the first end of the additional link connects the flexible link at the fourth pivotal point (P4) and the second end of the additional link connects the linkage at the fifth pivotal point (P5), such that the nipper drive shaft upon oscillation drives the top nipper plate and the bottom nipper plate, thereby moving the nipper plates to either closing or open position at precise time interval.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
Figure1 illustrates nipper drive arrangement for a textile combing machine, according to an embodiment of the present invention; and
Figure2 illustrates the linkage arrangement as preferred according to the present invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, and features.
DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
As shown in figure-1, the nipper drive arrangement for a textile combing machine comprising of a top nipper plate (7) connected to a nipper drive shaft (1) through a link arrangement comprising of a nipper crank (2), a coupler link (3), a top nipper connecting link (4), a top nipper shaft (5) and a flexible link (9). The nipper crank (2) having a first nipper crank end and a second nipper crank end, coupled to the nipper drive shaft (1) at the first nipper crank end, and the second nipper crank end is pivotally connected to the first end of the coupler link (3) at a first pivotal point (P1). Similarly, the top nipper connecting link (4) having a first end and a second end, wherein the first end of the top nipper connecting link isconnected to the second end of the said coupler link (3)at a second pivotal point (P2) and coupled to the top nipper shaft (5) through the second end of the top nipper connecting link. Thus, the first and second ends of coupler link (3) connected to first pivotal point (P1) and second pivotal point (P2) respectively and thereby the nipper crank (2), the coupler link (3), the connecting link (4) and a virtual linkage-I (VI) forms an anti-parallelogram four bar linkage (2-3-4-VI). The said virtual linkage-I (VI) is an imaginary ground link between the bottom nipper drive shaft (1) and the top nipper shaft (5). Further, the flexible link (9) having a first end and a second end connected to the top nipper shaft (5) through its first end at third pivotal point (P3) and to the top nipper plate (7) at the second end of the flexible link. The top nipper shaft (5) drives the top nipper plate (7) through the flexible link (9). Said flexible link (9) is provided with a spring arrangement whose length can be changed when a force acting on it.
The drive arrangement further comprising of a bottom nipper plate (8) coupled to the nipper shaft (1) and to a circular comb shaft (6), wherein the bottom nipper plate (8) is coupled to the nipper shaft (1) through a linkage (12), and a rocking lever (13), whereas the bottom nipper plate (8) is coupled to the circular comb shaft (6) through a connecting lever (11). The connecting lever (11), the linkage (12), the rocking lever (13), and a virtual linkage-II (VII) forms a four-bar linkage mechanism (11-12-13-VII). Virtual linkage-II (VII) is an imaginary ground link between the bottom nipper drive shaft (1) and the circular comb shaft (6).
Further the drive arrangement includes an additional link (14) having a first end and a second end, wherein the first end of the additional link connects the flexible link (9) at the fourth pivotal point(P4) and the second end of the additional link connects the linkage (12) at the fifth pivotal point(P5), such that the angular velocity of the top nipper plate (7) dependent on the acceleration and velocity of both top nipper shaft (5) and bottom nipper plate (12). Thus, the top nipper plate with the help of fourth pivotal point(P4) on flexible link (9) and the fifth pivotal point(P5) provides the necessary gripping force on the bottom nipper plate(12) for gripping the fibers while being combed.
The nipper drive shaft (1) is continuously oscillated in a rocking manner by any preferred drive arrangement (not shown in fig), to drive the top nipper shaft (5). Hence the top nipper connecting link (4) which linked to top nipper shaft (5) moves with respect to the angular velocity and acceleration of the drive shaft (1). There by top nipper plate (7) and bottom nipper (8) operatively comes to closing position at precise time interval as illustrated by dotted lines in Figure -1 and to open position illustrated as solid lines.
The top nipper shaft’s (5) instantaneous varying angular velocity oscillatory motion is the output of the anti-parallelogram four bar linkage mechanism (2-3-4-VI). And the motion of the bottom nipper (8) depends on the four-bar linkage (13-12-11-VII) which is driven by oscillating nipper shaft (1). The linkage of the said nipper crank (2), coupler link (3), and top nipper connecting link (4) are mounted in Z type manner by which said nipper crank (2) in the operating zone is always at the third quadrant (Q3) with reference to its drive center as shown in Figure-2.
The adjustment of nipper movement is a requirement in combing machine, and hence the opening (Position-1) and closing (Position-2) of top and bottom nippers (7, 8) will be changed according to the nipper movement. For varying distances of detaching roller nipping point to bottom nipper feed roller nipping distance, the graduation marks (G) are provided on the top nipper connecting link (4). Also, an indication mark is provided on the top nipper shaft (5) to align the orientation of the top nipper connecting link(4) with respect to said graduation marks (G). According to the invention this improved nipper drive mechanism provides the minimum nipper movement with optimized closing and opening of top and bottom nippers. Thereby a control on nipper opening and closing with less nipper movement is achieved which results good quality piecing and detaching of the fibers without any higher vibration even while the machine operated in a speed, more than 600 nips/min.
Moreover, the better control on nipper opening and closing time with less nipper movement, provides a continuously changing ratio between said nipping cycles. In the represented figure-1 & 2, the angle (?8) between the virtual ground link (VI) and the nipper crank (2) is approximately between 70° to 140° and preferably between 90°-110° during nipper open condition. Whereas at nipper closing condition / backward most condition, the angle (?8) will be approximately between 40° to 110° and preferably between 60°-90°. Thus, the angular movement (?3) of the top nipper shaft (5) changes the angle of the top nipper with respect to the bottom nipper during nipper closing (?4) and nipper opening (?5). And therefore, the ratio of peak angular velocity during the nipper closing motion and nipper opening motion is approximately in the range of 1.5:1. Thus the driven link of the four bar is operated with the angular velocity of 7-8 rad/s from nipper opening to closing and whereas at 4.5-5.5 rad/s during nipper closing to opening motion. Moreover, the ratio of peak angular velocity and average angular velocity during the nipper closing motion is approximately in the range of 1.6:1 to 1.7:1 and the top nipper driven link is operated at more than its mean angular velocity which is greater than 40% of the nipper closing motion.
And the ratio of peak angular velocity and average angular velocity during the nipper opening motion is approximately in the range of 1.5:1 to 1.6:1 and the top nipper driven link is operated at more than its mean angular velocity which is greater than 50% of the nipper opening motion.
For exemplary the embodiment of this invention employs an anti-parallelogram four bar mechanism. Various modifications to these embodiments are apparent to those skilled in the art from the description and drawings herein. Therefore, the description is not intended to be limited to the embodiment shown along with the accompanying drawings but is to be provided broadest scope consistent with the principles and novel and inventive features describe/disclosed or suggested herein. Any modifications, equivalent substitutions, improvements etc. within the spirit and principle of the present invention shall all be included in the scope of protection of the present invention.
,CLAIMS:I/we claim,
1. A nipper drive arrangement for a textile combing machine adapted to drive the top nipper shaft (5) of a combing machine comprising at least an anti-parallelogram linkage mechanism.
2. The nipper drive arrangement as claimed in claim 1, wherein the anti-parallelogram linkage mechanism comprises a nipper crank (2), a coupler link (3), a top nipper connecting link (4) and a virtual linkage – I (VI).
3. The nipper drive arrangement as claimed in claim 2, wherein the nipper crank (2) having a first nipper crank end and a second nipper crank end, coupled to the nipper drive shaft (1) at the first nipper crank end, and the second nipper crank end is pivotally connected to the first end of the coupler link (3) at a first pivotal point (P1);
the top nipper connecting link (4) having a first end and a second end, wherein the first end of the top nipper connecting link (4) is connected to the second end of the said coupler link (3)at a second pivotal point (P2) and coupled to the top nipper shaft (5) through the second end of the top nipper connecting link (4);
a flexible link (9) having a first end and a second end connected to the top nipper shaft (5) through its first end at third pivotal point (P3) and to the top nipper plate (7) at the second end of the flexible link (9) at pivotal point (P4).
4. The nipper drive arrangement as claimed in claim 2, wherein the drive arrangement further comprising a bottom nipper plate (8) coupled to the nipper shaft (1) and to a circular comb shaft (6), wherein the bottom nipper plate (8) is coupled to the nipper shaft (1) through a linkage (12), and a rocking lever (13), whereas the bottom nipper plate (8) is coupled to the circular comb shaft (6) through a connecting lever (11); and
an additional link (14) having a first end and a second end, wherein the first end of the additional link connects the flexible link (9) at the fourth pivotal point(P4) and the second end of the additional link connects the linkage (12) at the fifth pivotal point(P5), such that the nipper drive shaft (1) upon oscillation drives the top nipper plate (7) and the bottom nipper plate (8), thereby moving the nipper plates to either closing or open position at precise time interval.
5. The nipper drive arrangement as claimed in claim 2, wherein said virtual linkage-I (VI) is an imaginary ground link between the bottom nipper drive shaft (1) and the top nipper shaft (5).
6. The nipper drive arrangement as claimed in claim 2, wherein the nipper crank (2) in the operating zone is always at the third quadrant (Q3) with reference to its drive center.
7. The nipper drive arrangement as claimed in claim 2, wherein the top nipper connecting link (4) further comprises embossed graduation marks (G).
8. The nipper drive arrangement as claimed in claim 7, wherein said top nipper shaft (5) includes an indication mark to align the orientation of the top nipper connecting link(4) with the graduation marks (G).
9. The nipper drive arrangement as claimed in claim 2, wherein the angle (?8) between the virtual ground link-I (VI) and the nipper crank (2) in nipper open position is in the range of 70° to 140° and preferably in the range of 90°-110°.
10. The nipper drive arrangement as claimed in claim 2, wherein the angle (?8) between the virtual ground link-I (VI) and the nipper crank (2) in nipper closed position is in the range of 40° to 110° and preferably in the range of 60°-90°.
11. The nipper drive arrangement as claimed in claim 4, wherein the ratio of peak angular velocity during the nipper closing motion and nipper opening motion is in the range of 1.5:1.
12. The nipper drive arrangement as claimed in claim 4, wherein the driven link of the four bar is operated with the angular velocity of 7-8 rad/s from nipper opening to closing motion, whereas at 4.5-5.5 rad/s during nipper closing to opening motion.
13. The nipper drive arrangement as claimed in claim 4, wherein the ratio of peak angular velocity and average angular velocity during the nipper closing motion is in the range of 1.6:1 to 1.7:1.
14. The nipper drive arrangement as claimed in claim 4, wherein the ratio of peak angular velocity and average angular velocity during the nipper opening motion is in the range of 1.5:1 to 1.6:1.

(MANOJ KUMAR D) \

Agent for Applicant
Krishna & Saurastri Associates LLP
Registration No. IN/PA - 2110