DESC:FIELD OF THE INVENTION

The present invention relates to textile spinning preparatory machine and more specifically the invention relates to the drive mechanism for detaching rollers of a textile combing machine.

BACKGROUND OF THE INVENTION

The spinning preparatory machines like carding, combing machines are used to process the fiber and optimize them for further spinning machine. Combing machine is one of the quality improving spinning preparatory machines, wherein the main objective of the combing machine is to remove the short fibers. Known textile combing machine has eight combing heads; each combing head comprises nipper unit, combing unit and detaching roller unit. Every combing head processes separate fiber lap rolls. Fibers of predetermined length are fed to the nipper unit where the nipper unit has two oscillating nipper plates namely top nipper plate and bottom nipper plate. The said nipper unit clamps the fed fibers during every forward movement of its oscillations in such a manner that one side of fiber bunch is hanging outside. Meanwhile the continuously rotating circular comb / cylindrical combing unit combs out the short fiber from hanging fibers. Then the combed fibers are further moved towards the pair of detaching rollers by the forward movement of nipper plates. During this forward movement of the web, said pair of detaching rollers rotates 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. Subsequently, when the pair of detaching rollers is rotated in fast forward direction, the web is drawn from the nipper unit and the rear end of the said web is combed by the top comb then pieces into the web. While such operation is repeated, the web fed by the respective combing heads is bundled and drafted. Subsequently, the calender rollers arrangement compresses the bundled and drafted web to form a combed sliver.

Generally, the detaching roller pairs are driven through a known six bar mechanism disclosed in application no: 2688/CHE/2009 as shown in Figure-1. This drive arrangement consists of an oscillating bottom nipper shaft (1) with a rocker (1a); a rotating main drive shaft (2) with a first crank (2a); and a detaching roller (3) arrangement with a second crank (3a); wherein said first crank (2a) and second crank (3a) are hinged to the same point on the rocker (1a) by means of couplings (4, 5) respectively. Hence the aforementioned rocker (1a), first crank (2a) of main drive shaft, second crank (3a) of detaching roller couplings (4), (5) and virtual links (VL) forms a differential six bar mechanism to drive the detaching roller (3). This differential six bar mechanism is used to drive the detaching rollers for a machine speed up to 600 Nips per minute. Thereof it becomes difficult to optimize the detaching roller motion curve for further higher machine speed with lesser acceleration/deceleration (approx<300m/s2) for better quality of combed fleece.

When the machine speed is increased more than 600 nips per minute, the mechanical forces are increased which results in increase of bearing load, power, vibration, noise and heat to an unacceptable level. Hence to achieve higher machine speed it becomes necessary to reduce the bearing load and machine vibration and the same can be achieved by optimizing the detaching roller motion curve. The known detaching roller drive mechanism fails in easy optimization due to complicated linkage assembly and flexibility. So, an alternate detaching roller mechanism which overcome the said disadvantages need to be invented.

OBJECTS OF THE INVENTION

The object of the present invention is to provide an improved linkage mechanism for driving detaching rollers and achieve higher speed by simplified linkages.

Another object of the present invention is to provide an optimized setting angle range for detaching roller motion.

Yet another object of the present invention is to minimize size of working components thereby reduce the machine vibration and power consumption.

SUMMARY OF THE INVENTION

The following disclosure presents a simplified summary of the invention in order to provide a basic understanding of some features of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

One aspect of present invention is to provide a drive mechanism for detaching rollers of a textile combing machine comprising:
an oscillating bottom nipper shaft with a rocker arm;
a rotating main drive shaft with a first crank; and
a detaching roller drive shaft with a second crank;
characterized in that said first crank of said rotating main drive shaft and said second crank of said detaching rollers mechanism are hinged respectively to two different pivotal points on said rocker arm by means of a connecting member and a pair of coupling links respectively, thereby forming a ternary linkage between nipper drive shaft and detaching roller drive shaft and differentially transferring the oscillation drive from the nipper shaft to the detaching roller drive shaft through the said coupling links.

In a preferred embodiment of present invention, said ternary linkage comprises three pivotal joints such that the angle between at least two pivotal points of said three pivotal joints is 3º to 8º.

In another preferred embodiment, said angle between at least two pivotal points of said three pivotal joints is 6º with radial centre point of nipper drive shaft as an angle of centre.

In a preferred embodiment, the pivotal points or nodes and radial centre of nipper drive shaft make a ternary link region having three sides of unequal lengths wherein the shortest length side of said ternary link region is adapted to determine the distance between said two pivotal points or nodes.

In another preferred embodiment, the ratio of the lengths of remaining two sides of said ternary link region is in the range of 0.5-1.

In a more preferred embodiment, the ratio of the lengths of remaining two sides of said ternary link region is in the range of 0.5-0.9.

In a most preferred embodiment, the ratio of the lengths of remaining two sides of ternary link region is 0.75.

Other salient features and advantages, of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING 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:

Figure 1 shows existing six bar mechanism of detaching roller drive.

Figure 2 illustrates the ternary link detaching roller drive mechanism according to the present invention.

Figure 2a shows another preferred embodiment according to the present invention.

Figure 3 shows the drive linkage mechanism of 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, features, and structures.

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. 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 of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

The terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

The subject invention lies in a drive mechanism for detaching rollers of a textile combing machine comprising:
an oscillating bottom nipper shaft with a rocker arm;
a rotating main drive shaft with a first crank; and
a detaching roller drive shaft with a second crank;
characterized in that said first crank of said rotating main drive shaft and said second crank of said detaching rollers mechanism are hinged respectively to two different pivotal points on said rocker arm by means of a connecting member and a pair of coupling links respectively, thereby forming a ternary linkage between nipper drive shaft and detaching roller drive shaft and differentially transferring the oscillation drive from the nipper shaft to the detaching roller drive shaft through the said coupling links.

In a preferred embodiment of present invention, said ternary linkage comprises three pivotal joints such that the angle between at least two pivotal points of said three pivotal joints is 3º to 8º.

In another preferred embodiment, said angle between at least two pivotal points of said three pivotal joints is 6º with radial centre point of nipper drive shaft as an angle of centre.

In a preferred embodiment, the pivotal points or nodes and radial centre of nipper drive shaft make a ternary link region having three sides of unequal lengths wherein the shortest length side of said ternary link region is adapted to determine the distance between said two pivotal points or nodes.

In another preferred embodiment, the ratio of the lengths of remaining two sides of said ternary link region is in the range of 0.5-1.

In a more preferred embodiment, the ratio of the lengths of remaining two sides of said ternary link region is in the range of 0.5-0.9.

In a most preferred embodiment, the ratio of the lengths of remaining two sides of ternary link region is 0.75.

Combing machine with improved detaching rollers mechanism according to the present invention is shown in Figure-2. The six-bar linking mechanism as described in the present invention comprises, a rocker arm (1a) pivotally fixed on the nipper drive shaft (1); a detaching roller crank (3a) coupled to the detaching roller drive shaft (3) and a main drive crank (2a) coupled to the main drive shaft (2). Both cranks (3a), (2a) are hinged to the rocker arm (1a) by means of coupling links (5) and (4) respectively. This forms a rocking angle (?) for the said ternary link of the rocker arm (1a). The said coupling links (5) and (4) are hinged at pivotal points (6) and (7) respectively provided in rocker (1a). Hence, the oscillation drive from the nipper shaft (1) is differentially transferred to the detaching roller shaft (1) through the said coupling links (5, 4).

As shown in figure-2, the pivotal points or nodes (6), (7) and radial center (8) of nipper drive shaft (1) makes a ternary link region (9) with (9a), (9b) and (9c) as perimeter sides. Thus, according to the invention said ternary link never be an isosceles triangle. And therefore, this ternary link forms a shortest length side (9a) of ternary link which always determines the distance between the said two pivotal points or nodes (6,7). According to the proposed six bar drive arrangement as shown in Figure-2a with shifted up pivotal point (7), to solve the background art problem, the rocking ternary link (9) having an interior angle ?1 formed by the two adjacent sides of the triangle (9b,9c). Said sides joining vertex is connected to the nipper shaft ground through a revolute joint (8) which is preferably in the range of 3º