FIELD OF THE INVENTION

[0001] The present invention generally relates to textile machinery and embodiments of the invention particularly relates to combing cylinder and combing segment of a textile fibre comber.

BACKGROUND

[0002] In the textile combing machines, textile fibres for example cotton fibres are fed in the form of lap sheets. During combing operation, the lap sheet is fed by way of feed roller in to the combing section through nipper assembly. In combing section, a combing segment is fitted on the combing cylinder which is mounted below nipper assembly. The fed fibre lap is combed by combing segment by continuous rotation of combing cylinder. After combing has been done, the noil-free cotton is collected in the form of fibre web by a pair of detaching roller arrangement. The noil removed by the combing cylinder is taken by the brush roller and collected through suction. The fibre web delivered from detaching roller arrangement is converted as sliver by a trumpet and moved to the further drafting process.

[0003] The combing cylinder is driven by a driving means and nippers are oscillated by means of an oscillating nipper shaft. Said oscillating nipper shaft is mounted on the machine frame and driven by a slider crank mechanism. For each revolution of combing cylinder, the oscillating shaft makes one to and fro motion to the bottom nipper and this movement of nipper is so called as nipping speed.

[0004] A nipping speed up to 500 nips per minute is achieved in the machines known to be in operation. However, in the combing technology present in the machines available in the art, moving the nipper frame at higher velocity creates considerable vibrations in the machine. When the nipper velocity increases correspondingly the detaching roller velocity also increases. The increase in the velocity of the detaching roller increases the acceleration and deceleration of detaching rollers as well as the cotton fibres, which results in poor web and quality of the fibres combed.

[0005] It is known that the nipping speed of combing machines is directly related to moving distance of nippers. Decreasing the moving distance of nippers is not possible due to the diameter of existing combing cylinder. If the nipper movement decreased than certain extent, the nipper hinders with combing cylinder and damages the wire points of combing segment. Also, the clearance between combing segment and nipping point cannot be maintained uniformly throughout the combing circle which has considerable influence on the output quality of the fibre which is disadvantageous.

[0006] There has thus been a persistent need to develop a combing cylinder that would increase nipping speed of the combing machine without compromising the output quality. The present invention would provide an improved combing machine that would overcome all disadvantages present in the existing combing machines.

OBJECT OF THE INVENTION

[0007] It is thus the basic object of the present invention to provide a combing cylinder which avoids aforementioned disadvantages of the conventional combing cylinder in the existing combing machines.

[0008] Another object of the present invention is to provide a textile combing machine with improved combing cylinder that will improve the nipping speed and out put quality compared to the existing combing machines.

[0009] Still another object of the present invention is to provide a textile combing machine with improved top nipper driving mechanism that will improve the nipping speed and out put quality compared to the existing combing machines.

SUMMARY OF THE INVENTION

[0010] One aspect of the invention includes combing assembly of a textile fibre lap comber having a combing shaft configured for unidirectional rotation. A combing cylinder is mounted on the combing shaft, a combing segment having a plurality of saw toothed wires is mounted on the combing cylinder and the radius of said combing cylinder is less than 62.7mm.

[0011] In accordance with the aspect of the invention, the radius of the combing cylinder is in the range of 30mm to 60mm and the combing angle of said combing segment is in the range of 111° to 180°.

[0012] In accordance with another aspect of the invention, the ratio of combing angle of the combing segment to the radius of the combing cylinder is varied to achieve better nipping speed. The radius of the combing cylinder is reduced from 62.7 mm and the combing angle is increased from 111 ° to achieve the required ratio. The ratio of combing angle of the combing segment to the radius of the combing cylinder is preferably in the range of 1.8 to 4.0.

[0013] In accordance with still another aspect of the invention, to achieve the desired opening and closing movement and the clamping time of the top nipper, said top nipper is directly and separately operated by a driving arrangement with a four bar link mechanism anu gearing arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to various embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

[0015] FIG. 1 illustrates a schematic view of combing assembly according to an embodiment of the invention.

[0016] FIG.2a illustrates a schematic view of combing assembly according to one example of the invention.

[0017] FIG.2b illustrates a schematic view of combing assembly according to another example of the invention.

[0018] FIG.2c illustrates a schematic view of combing assembly according to yet another example of the invention.

[0019] FIG - 3 illustrates a schematic view of top nipper drive arrangement in accordance to an embodiment of the invention.

DETAILED DESCRIPTION OF INVENTION

[0020] Various embodiments of the invention describe a combing cylinder of a textile combing machine. FIG. 1 illustrates a schematic view of combing assembly 1 according to an embodiment of the invention. The combing assembly 1 includes of a combing cylinder 2 mounted on a combing shaft not shown in the figure. A combing segment 3 having plurality of saw tooth wires 4 is mounted on the combing cylinder 2. The combing segment 3 is mounted along a portion of the peripheral surface concentric with the combing cylinder 2. The combing segment 3 mounted concentric to the combing cylinder 2 forms a combing surface which includes a combing starting point A and a combing ending point B. The angle suspended between the combing starting point A and the combing end point B is referred to hereinafter as combing angle β. The distance between rotational axis O of the combing cylinder 2 to the combing starting point A of the combing segment 3 is hereinafter referred to as radius R. The choice of the radius R of the combing cylinder and the combing angle |3 determines the efficiency of the fibre combing. In an embodiment of the invention, the ratio of the combing angle β to the radius of the combing cylinder R is chosen to determine combing efficiency.

[0021] The fibres to be combed are gripped between a top nipper 5 and a bottom nipper 6 operably mounted above the combing segment 3.The top nipper 5 and the bottom nipper 6 are included in a nipper drive arrangement, the arrangement of which shall be described in detail in the description to follow. The top nipper 5 and the bottom nipper 6 are configured to execute a reciprocating motion in conjunction with the movement of the combing segment 3. The reciprocating motion of the top nipper 5 and the bottom nipper 6 in conjunction with the movement of the combing segment 3 initiates a combing action. The combing action of a combing segment 3 is influenced by a clearance gauge S between the nip portion 7 and the projections 4 on the combing segment 3. The clearance gauge S is relatively narrow as 0.3 - 0.5 mm in the known art.

[0022] Figs 2a, 2b and 2c generally illustrate a schematic view of the combing assembly according to various embodiments of the invention. More particularly, Figs 2a, 2b and 2c illustrate the choice of the radius R of the combing cylinder and the combing angle (3, according to various examples of the invention. In an embodiment of the invention, the ratio of the combing angle (3 to the radius of the combing cylinder R was chosen preferably in the range of 1.8 to 4.0. The above ratio can be arrived by using the following formula.

In order to satisfy the ratio range referred to herein before, the radius R can be preferably chosen in the range of 30mm to 60 mm and the combing angle (3 of combing segment 3 can be preferably chosen in the range of 1110 to 180°.

[0023] In one example of an embodiment of the invention, for a ratio of 2.0, the combing angle (3 was chosen to be at 120° and the corresponding radius R of the combing cylinder was chosen to be at 60mm. Similarly, according to another example of the embodiment of the invention, for a ratio of 3.0, the combing angle (3 was chosen to be at 150° and the radius R of the combing cylinder was chosen to be at 50mm. In an alternate example of the invention, for a ratio of 3.91, the combing angle β was chosen to be at 180° and the corresponding radius R of the combing cylinder was chosen to be at 46mm.

[0024] FIG - 3 illustrates a schematic view of top nipper drive arrangement in accordance to an embodiment of the invention. In an embodiment of the invention, the nipper drive arrangement includes a nipper shaft 11 having a first end 11a and a second end 1 lb. The nipper shaft is operably coupled to a circular comb shaft 12. A first eccentric disc 15 with a connecting arm 16 is rotatably mounted onto the circular comb shaft 12. The trailing end of connecting arm 16a is coupled to a gear arrangement. The gear arrangement includes a gear shaft 18 mounted to the frame 21 of the textile fibre comber. A quadrant gear 17 is rotatably mounted on the gear shaft 18. The quadrant gear 17 drives a gear 20 mounted on the first end of nipper shaft 11 a through an intermittent gear 19. The top nipper 5 is mounted on the second end of the nipper shaft 1 lb through a second eccentric disc 10. The nipper drive arrangement as described hereinabove converts the unidirectional rotation of circular comb shaft 12 into an opening and closing movement of top nipper 5 and the desired clamping time is achieved by altering the above described four bar link mechanism F and gearing arrangement G.

[0025] The invention allows the following advantages to be obtained. The moving distance of bottom nipper is minimized and by this collision between bottom nipper and combing cylinder is avoided. Advantageously, combing surface can be increased and the clearance between nip portion and combing segment is minimized and maintained uniform while combing. The nipping speed can be increased up to 700 nips per minute and the feed lap weight can be increased up to 100 gms per metre. By maintaining desired clearance, higher lap weight with desired quality is achieved. Advantageously, overall productivity is improved. The described combing cylinder facilitates increase in nipping speed and level of combing and results in higher productivity and improved quality of delivered fibre material.

[0026] The invention, as described herein and as illustrated by diagrams provides a combing assembly for a textile machine such as a fiber lap comber. The foregoing description of the invention has been set for merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

CLAIMS:

1. A combing assembly for a textile machine such as a fibre lap comber comprising of

a combing shaft configured for unidirectional rotation;

at least one combing cylinder with a predefined radius rotatably mounted on the combing shaft;

a combing segment having a plurality of projections on the combing cylinder describing a predefined combing angle; and

a nipper drive arrangement configured for driving a top nipper through the combing shaft.

Characterized in that the ratio of combing angle of the combing segment to the radius of the combing cylinder is in the range of 1.8 to 4.0.

2. The combing assembly according to claim 1, wherein the radius of the combing cylinder is in the range of 30mm to 60mm.

3. The combing assembly according to claim 1, wherein the combing angle of the combing segment is in the range of 110° to 180°.

4. The combing assembly according to claim 1, wherein the nipper drive arrangement comprises of

a first eccentric disc with a connecting arm rotatably mounted on the combing shaft; a gear arrangement coupled to the connecting arm;

a nipper shaft having a first end and a second end coupled to the gear arrangement.

5. The gear arrangement according to claim 4, wherein the gear
arrangement comprises of

a gear shaft mounted to the frame of the textile fiber comber;

a quadrant gear rotatably mounted on the gear shaft; and

a gear mounted on the first end of the nipper shaft wherein the gear is operably coupled to the quadrant gear through an intermediate gear.

6. The nipper drive arrangement according to claim 4, further comprising of the top nipper operably coupled to the combing segment through a second eccentric disc mounted on the second end of the nipper shaft.

7. The gear arrangement according to claim 4, wherein the gear arrangement converts the rotational movement of the combing shaft into an open and close movement of the top nipper.

8. A combing assembly for a textile machine such as a fiber lap comber as illustrated in the accompanying drawings and as described in the specification.