FIELD OF THE INVENTION

This invention relates to the drive system of a textile combing machine. More particularly, this invention relates to the nipper drive arrangement to drive the top nipper of a textile combing machine.

BACKGROUND OF THE INVENTION

It is known that textile combing machine employs a nipper unit having top nipper and bottom nipper. The bottom nipper is reciprocated back and forth relative to a comb cylinder and the top nipper is pivotally mounted and connected with the bottom nipper so as to move between an open position and a closed position relative to the movement of the bottom nipper. When in the open position, the fibre tuft is fed between the two nippers whereas in the closed position, the two nippers grasp a leading end of the fibre tuft so that combing action is performed by the comb cylinder.

In the known combing machines, the top nippers are driven by an arrangement comprising drive gear mounted on the reciprocating bottom nipper drive shaft. The drive gear transmits the rotary motion to an idler gear. The idler gear subsequently transmits the rotary motion to a driven gear mounted on the top nipper shaft which incorporates reciprocating motion to the top nipper through an eccentric cam. In this arrangement the angular displacement (velocity and acceleration) of top nipper shaft is proportional to the bottom nipper drive shaft's angular displacement (velocity and acceleration). Since the bottom nipper is also driven by the same nipper shaft, altering the motion of the top nipper shaft in a non-linear fashion irrespective of the motion fashion of the bottom nipper shaft is not possible.

It will be advantageous if the motion of the top nipper shaft is in non-linear relationship with the bottom nipper shaft's motion. Then it will be possible to control the angular displacement (velocity and acceleration) of the top nipper, the closing and opening time of nippers, required nipper opening at certain indices and the piecing time of combed fringe at the detaching nip point. Here the term "linear" represents, in a gear train, motion parameters of one gear is proportional to the other gear which is meshing with it. The proportionality is equal to gear ratio which is a constant depending upon the number of teeth. If a linkage mechanism is employed instead of gear train, the proportionality will not be a constant. It can be varied with input motion and also it can be varied depending upon the linkage lengths.

It is known in the art, the mechanical drive to the eccentric shaft of the top nipper can be replaced by a drive from electric motor. With this mechanism it is now possible to attain different movement curves of the top nippers irrespective of the bottom nippers. Further the top nippers are well balanced and precisely swung even at the higher combing cycles.

Though in the above arrangement it is possible to have motion of the top nipper shaft independent of the motion of the bottom nipper shaft, it involves additional motor, which is expensive. And also it requires synchronisation of two motors of top and bottom nipper drive shafts.

OBJECT OF THE INVENTION

It is an object of the invention to provide a top nipper shaft drive arrangement which is
relatively simple in construction and cost effective which will facilitate the motion of the
top nipper shaft having non-linear relationship with the motion of the bottom nipper shaft.

It is another object of the invention to provide the drive arrangement for top nipper
which permits increased production in a combing machine.

It is yet another object of the invention to provide a drive arrangement for top nipper of
a combing machine which does not require gear transmission.

SUMMARY OF THE INVENTION

According one aspect of the present invention there is provided a nipper drive arrangement of a textile combing machine adapted to drive top nipper drive shaft of a combing machine comprising at least one FOUR bar linkage mechanism:

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1 depicts the system to drive the top nipper drive shaft of the combing machine of known type.

Figure 2 depicts the system to drive the top nipper drive shaft of the combing machine according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF INVENTION

The present invention provides a nipper drive arrangement to drive the top nipper drive shaft of the combing machine with a help of FOUR bar link mechanism which facilitates means for adopting the required motion pattern of top nipper which is having non-linear relationship with the motion pattern of the bottom nipper and the bottom nipper drive shaft.

In a preferred embodiment of the present invention four bar linkage mechanism of the nipper drive arrangement is operatively connected to top and bottom nipper shafts and is adapted to transmit reciprocating motion of the bottom nipper drive shaft to the top nipper drive shaft having non-linear relationship with the reciprocating motion of the bottom nipper drive shaft.

The combing machine comprises a plurality of combing heads. Each combing head is provided with a nipper arrangement comprising bottom nipper and top nipper with means provided for driving them. The combing machine is further provided with continuously rotating circular comb shaft (1) driven by the drive system of the combing machine and provided to carry the circular combs of the plurality of the combing heads.

Referring to figure 1 of the accompanying drawings which depicts the nipper drive arrangement to drive the top nipper drive shaft of a known combing machine wherein reciprocating motion to the top nipper drive shaft (7) is provided by transmitting the reciprocating motion of the bottom nipper drive shaft (2) through gear train comprising drive gear (12) rigidly fitted to the bottom nipper drive shaft (2), idler gear (13) rotatably mounted on an intermittent axis and driven gear (14) rigidly fitted to the top nipper drive shaft (7).

Figure 2 of the drawings accompanying this specification illustrates the nipper drive arrangement adopted to drive the top nipper drive shaft of one of the heads of the combing machine according to the present invention.

A bottom nipper drive shaft (2) which is arranged substantially parallel to the said circular comb shaft (1) and driven by the drive system of the combing machine so as to provide the pre-determined reciprocating motion. The first end of the nipper crank arm (3) is rigidly fitted to the bottom nipper drive shaft (2) and its second end is pivoted to the bottom nipper (4) at its rear end at pivot point (P1). While front end of the said bottom nipper (4) is pivoted to the smaller end of the front nipper support (5) at pivot point (P2), the bigger end of the said front nipper support (5) is pivoted to said circular comb shaft (1) at pivot point (P3). The reciprocating motion of the said bottom nipper drive shaft (2) provides reciprocating motion to the said bottom nipper (4). The top nipper (6) is pivoted to the bottom nipper (4) at its lower end at pivot point (P4) and its upper end is pivoted to the top nipper drive shaft (7) at pivot point (P5) through an eccentric cam (8) and through a flexible link (15). While the reciprocating motion of the said bottom nipper drive shaft (2) provides the back and forth movement to the bottom and top nippers, the reciprocating movement of the said top nipper drive shaft (7) facilitates the opening and closing of the top nipper (6) through the eccentric cam (8) and the flexible link (15).

Figure 2 of the accompanying drawings depicts the nipper drive arrangement to drive the top nipper drive shaft of the combing machine according to the present invention. In the present invention reciprocating motion to the top nipper drive shaft (7) is provided by transmitting the reciprocating motion of the bottom nipper drive shaft (2) by a FOUR bar link mechanism which is having non-linear relationship with the reciprocating motion of the bottom nipper drive shaft (2).

The FOUR bar link mechanism comprises a drive link (9) referred as link 'A', a coupler link (10) referred as link 'B', a driven link (11) referred as link 'C and a virtual ground link (VGL) which connects the axis of the bottom nipper drive shaft (2) and the axis of the top nipper drive shaft (7).

The drive link (9) is provided with passage openings at its bigger and smaller ends. The coupler link (10) and the driven link (11) are also provided with passage openings at their both ends.

Through the passage opening provided at the bigger end, the drive link (9) is rigidly fitted to the bottom nipper drive shaft (2). The smaller end of the drive link (9) and the
first end of the coupler link (10) is pivotally connected at pivot point (P6). The second end of the coupler link (10) and the first end of the driven link (11) is pivotally connected at pivot point (P7). The second end of the driven link (11) is rigidly fitted to the top nipper drive shaft (7).

By varying the distance between the passage openings of the said drive link (9), the said coupler link (10) and the said driven link (11), it is possible to obtain the required motion pattern of said top nipper (6), which is having non-linear relationship with the motion pattern of the said bottom nipper (4) and the bottom nipper drive shaft (2).

Part no Description

1 Circular comb shaft
2 Bottom Nipper drive shaft
3 Nipper crank arm
4 Bottom nipper
5 Front nipper support
6 Top nipper
7 Top nipper drive shaft
8 Eccentric cam
9 Drive link
10 Coupler link
11 Driven link
12 Drive gear
13 Idler gear
14 Driven gear
15 Flexible link
P1 - P7 Pivot points

The invention has been described in a preferred form only and many variations may be made in the invention which will still be comprised within its spirit. The invention is not limited to the details cited above. The linkages as herein described do not limit the scope of the present invention and can be replaced by its technical equivalence and yet the invention can be performed. The structure thus conceived is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence. In practice the materials and dimensions may be any according to the requirements, which will still be comprised within its true spirit.

WE CLAIM

1. Nipper drive arrangement of a Textile Combing Machine adapted to drive top nipper drive shaft of a combing machine comprising at least one FOUR bar linkage mechanism.

2. The drive arrangement as claimed in claim 1, wherein the FOUR bar linkage mechanism is disposed to operatively connect the top nipper shaft (7) and bottom nipper shaft (2) and adapted to transmit reciprocating motion of the bottom nipper drive shaft (2) to the top nipper drive shaft (7).

3. The drive arrangement as claimed in claim 1 or 2, wherein said four bar linkage mechanism comprises drive link (9), coupler link (10), driven link (11) and virtual ground link (VGL).

4. The drive arrangement as claimed in claim 3, wherein virtual ground link (VGL) connects axis of the bottom nipper shaft (2) and. axis of the top nipper shaft (7).

5. The drive arrangement as claimed in claim 3, wherein drive link (9) is rigidly
fitted to the bottom nipper drive shaft (2) through passage opening provided at the bigger end.

6. The drive arrangement as claimed in claim 3 and 5 , wherein the drive link (9)is pivotally connected to coupler link (10) at pivot point (P6).

7. The drive arrangement as claimed in claim 3, wherein the coupler link B (10)is pivotally connected to the first end of driven link (11) at pivot point (P7).

8. The drive arrangement as claimed in claim 3 and 7, wherein one of the ends of the driven link (11) is rigidly fitted to the top nipper drive shaft (7).

9. The drive arrangement as claimed in any of the preceding claim, wherein the distance between the passage openings of the drive link (9), the coupler link (10) and the driven link (11) can be varied.

10. Drive arrangement adapted to drive top nipper drive shaft of a combing machine substantially as herein described with reference to the accompanying drawings.