DESC:FIELD OF THE INVENTION

The present invention relates to an improved drive arrangement for drafting rollers of textile ring spinning machine. More particularly, the invention relates to drive arrangement for the drafting rollers in long spinning machine with more number of spindles.

BACKGROUND OF THE INVENTION

Textile ring spinning machines comprises drafting arrangement for imparting a predetermined draft on the roving material before transforming into yarn. The said drafting arrangement generally comprises three-over-three / four-over-four drafting rollers in spinning machines. The bottom drafting rollers in a ring spinning machine is arranged such that it comprises front, middle and rear rollers extending along the entire length of the machine and are supported in bearings at spaced intervals. These bottom rollers are connected at one end by a gear train which is driven by a motor. Further, an additional delivery drafting roller (fourth roller) is provided in front of the above said drafting rollers in ring spinning machines for compact spinning.

The middle drafting roller rotates at a greater speed than rear drafting roller. The front drafting roller rotates at a greater speed than the middle drafting roller. The delivery drafting roller rotates at a greater speed than the front drafting roller. The ratio of the rotational speed of a drafting roller with respect to the preceding drafting roller called as ‘draft’ plays an important role in imparting twist to the fibres in ring spinning machines. The draft selection varies for different types and counts of fibres. The main drawback in the existing arrangement is that, for changing the draft between the bottom drafting rollers, gears have to be changed manually at the drive portions which is highly labour-intensive. This results in increased stoppage time of the machine for changing the gears. The gear inventory in mill sites is higher.

Another drawback is that, upon lengthening the machine with more number of spindles, say 2000 and above, excessive twisting of the rollers occurs due to torsional force applied to them. The degree of twist exhibited by these rollers varies from the driven end to free end.

Due to the aforementioned drawbacks, efficiency of the machine is greatly reduced. The present invention provides an improved drive arrangement for drafting rollers of ring spinning machine with more number of spindles, eliminating the above drawbacks.

OBJECTS OF THE INVENTION

It is an object of this invention to provide an improved drive arrangement for the drafting rollers of textile ring spinning machines.

It is another object of this invention to reduce the stoppage time of ring spinning machines.

It is another object of this invention to eliminate the gear inventory in mill sites of ring spinning machines.

It is yet another object of this invention to reduce the torsional force applied to the drafting rollers of long spinning machines.

It is yet another object of this invention to improve the performance of the textile ring spinning machines.

It is yet another object of this invention to provide a drive arrangement which is simple in construction.

SUMMARY OF THE INVENTION

According to the present invention an improved drive arrangement for drafting rollers of textile ring spinning machine is provided comprising at least four drafting modules provided between headstock and endstock wherein each module has a front roller, a split two-part middle roller and a split two-part rear roller, wherein an electric motor drives first part of the rear drafting rollers of the first and third modules at the headstock side; an electric motor drives first part of the rear drafting rollers of the second and fourth modules at the endstock side; an electric motor drives second parts of the rear drafting rollers of the each module; an electric motor drives first part of the middle drafting rollers of the first and third modules at the headstock side; an electric motor drives first part of the middle drafting rollers of the second and fourth modules at the endstock side; an electric motor drives second parts of the middle drafting rollers of the each module; an electric motor drives the front drafting rollers of the first and third modules at the headstock side; and an electric motor drives the front drafting rollers of the second and fourth modules at the endstock side.

According to another embodiment of the present invention, each of the drafting modules further includes a delivery drafting roller driven by the front drafting rollers through gear arrangements.

According to yet another embodiment of the present invention, each of the drafting modules further includes delivery drafting rollers driven by electric motor at the headstock side and delivery drafting rollers driven by electric motor at the endstock side.

According to yet another embodiment of the present invention, the electric motors are servo motors connected to one or more servo drives/frequency convertors.

According to yet another embodiment of the present invention, the servo drives/ frequency convertors are connected to a control unit.

According to yet another embodiment of the present invention, the electric motors are servo motors or induction motors or synchronous motors or asynchronous motors or a combination thereof.

According to yet another embodiment of the present invention, wherein the drafting rollers are supported at free ends by end bearings mounted on the brackets of machine roller stand.

According to still another embodiment of the present invention, the rear and middle drafting rollers are split into two shafts.

According to still another embodiment of the present invention, the shafts are split into two equal halves or at any point across the length.

According still another embodiment of the present invention, the modules at the headstock side are mirror symmetric arrangement of modules at the endstock side.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constitute a part of the description and are used to provide further understanding of the present invention. Such accompanying drawings illustrate the embodiments of the present invention which are used to describe the principles of the present invention together with the description.

Figure 1 illustrates schematic view of the drive arrangement for bottom drafting rollers in a textile ring spinning machine according to the present invention.

Figure 2 illustrates schematic view of the drive arrangement for bottom drafting rollers in a textile ring spinning machine with compact spinning arrangement according to the present invention.

Figure 3 illustrates schematic view of the drive arrangement for bottom drafting rollers in a textile ring spinning machine with compact spinning arrangement according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention may be better understood and further advantages and uses thereof more readily apparent, when considered in view of the following detailed description of exemplary embodiments, taken with the accompanying drawings. These embodiments describe only a few of the various ways in which the principles of various other embodiments may be realized and the described embodiments are intended to include all such embodiments and their equivalents and the reference numerals used in the accompanying drawings correspond to the like elements throughout the description.

The drafting arrangement of ring spinning machine according to the present invention is shown in Figure 1, wherein at least four drafting modules (A, B, C & D) are provided in between the headstock and endstock (not shown) of the machine frame. The headstock comprises the driving and transmission mechanism for spindles and ring rails, whereas the endstock comprises the suction and cleaning arrangements. The bottom drafting rollers (1, 2 & 3) are supported by end bearings mounted on the brackets of machine roller stand on both sides and along the entire length of the machine frame at regular intervals (not shown). The drafting arrangement with additional roller (4) for compact spinning arrangement according to the present invention is shown in Figures 2 & 3.

The modules (A & C) comprise either three or four bottom drafting rollers (1, 2, 3 & 4) on right row (A) and either three or four bottom drafting rollers (1’, 2’, 3’ & 4’) on left row (C) respectively. The rear drafting rollers (3 & 3’) are split into two equal length shafts as shown in figure 1. The rear drafting rollers (3 & 3’) are driven by a common motor (M3) at the headstock side. The rear drafting rollers (3 & 3’) are driven by another motor (M5) at the other side. The free ends at the center of the rear drafting roller shafts (3 & 3’) are mounted in end bearings (not shown). The rear bottom roller shafts (3 & 3’) are preferably split into two equal length shafts. The shafts can be split anywhere across the length as an embodiment. Further, the motor (M5) drives the rear drafting rollers (3’’ & 3’’’) at one side of modules (B & D), which is a mirror symmetric arrangement of modules (A & C).

Similarly, the middle drafting rollers (2 & 2’) of modules (A & C) are split into two equal length shafts. The middle drafting rollers (2 & 2’) are driven by a common motor (M2) at the headstock side. The middle drafting rollers (2 & 2’) are driven by another motor (M4) at the other side. The free ends at the center of the middle drafting roller shafts (2 & 2’) are mounted in end bearings (not shown). The middle bottom roller shafts (2 & 2’) are preferably split into two equal length shafts. The shafts can be split anywhere across the length as an embodiment. Further, the motor (M4) drives the middle drafting rollers (2’’ & 2’’’) at one side of modules (B & D), which is a mirror symmetric arrangement of modules (A & C).

The front drafting rollers (1 & 1’) of modules (A & C) are driven by a common motor (M1) at the headstock side and the other ends are freely mounted on end bearing (not shown). In compact spinning arrangement as shown in figure 2, the front drafting rollers (1 & 1’) drives the delivery drafting rollers (4 & 4’) through gear arrangements (5 & 5’) on right (A) and left (C) row of the machine frame respectively at the headstock side. The other ends of the delivery rollers (4, 4’) are freely mounted on end bearings (not shown).

Corresponding to the modules (B & D) which are symmetric to the modules (A & C), the rear drafting rollers (3’’ & 3’’’) are split into two equal length shafts as shown in figure 1. The motor (M5) is common for the rear drafting rollers (3, 3’, 3’’ & 3’’’) of modules (A, B, C & D). The rear drafting rollers (3’’ & 3’’’) are driven by another motor (M8) at the endstock side. The free ends at the center of the rear drafting roller shafts (3’’ & 3’’’) are mounted in end bearings (not shown). The rear bottom roller shafts (3’’ & 3’’’) are preferably split into two equal length shafts. The shafts can be split anywhere across the length as an embodiment.

Similarly, the middle drafting rollers (2’’ & 2’’’) of modules (B & D) are split into two equal length shafts. The motor (M4) is common for the middle drafting rollers (2, 2’, 2’’ & 2’’’) of modules (A, B, C & D). The middle drafting rollers (2’’ & 2’’’) are driven by another motor (M7) at the endstock side. The free ends at the center of the middle drafting roller shafts (2’’ & 2’’’) are mounted in end bearings (not shown). The middle bottom roller shafts (2’’ & 2’’’) are preferably split into two equal length shafts. The shafts can be split anywhere across the length as an embodiment.

The front drafting rollers (1’’ & 1’’’) are freely mounted on end bearings at one end (not shown). The front drafting rollers (1’’ & 1’’’) are driven by a common motor (M6) at the endstock side. In compact spinning arrangement as shown in figure 2, the front drafting rollers (1’’ & 1’’’) drives the delivery drafting rollers (4’’ & 4’’’) through gear arrangements (5’’ & 5’’’) on right (B) and left (D) row of the machine frame respectively at the endstock side.

According to another embodiment as shown in figure 3, for compact spinning machine, the delivery drafting rollers (4 & 4’) of modules (A & C) are driven by a common motor (M9) at the headstock side instead of gear drive from front drafting rollers (1 & 1’). The other ends are freely mounted on end bearings. Similarly, the delivery drafting rollers (4’’ & 4’’’) of modules (B & D) are driven by a common motor (M10) at the endstock side. The other ends are freely mounted on end bearings.

The electric motors (M1, M2, M3, M4, M5, M6, M7, M8, M9 & M10) are preferably servo motors. As an embodiment, the electric motors include induction motors, synchronous motors and asynchronous motors. The above arrangement is very advantageous for ring spinning machines with more number of spindles, i.e. long spinning machines with upto 2400 spindles and above.

The drafting roller drives (M1 to M10) are connected to one or more servo drives/frequency converters (not shown). The said servo drives/frequency converters are connected to a control unit with Man-Machine interface, i.e. display. The draft change according to the requirement can be entered at the display unit thereby precise draft is achieved in a user-friendly manner.

The above drive arrangement for drafting rollers in ring spinning machine eliminates large numbers of gears for different draft ratio. Thereby, inventory of gears in spinning mill sites is considerably reduced. Since the four drafting modules are separated from each other in between the machine frame, uniform torsional force distribution is achieved over entire length of the bottom drafting rollers in long spinning frame for approximately 2400 spindles. Preferably, the application of servo drives for the drafting rollers in ring spinning paves way for increasing the number of spindles without torsional disturbances. This is trouble-free in operation and simple in construction. Thereby, performance of ring spinning machines is improved.

In view of the present disclosure which describes the present invention, all changes, modifications and variations within the meaning and range of equivalency are considered within the scope and spirit of the invention.

,CLAIMS:We claim:

1. An improved drive arrangement for drafting rollers of textile ring spinning machine comprising at least four drafting modules (A, B, C, D) provided between headstock and endstock wherein each module has a front roller, a split two-part middle roller and a split two-part rear roller,
characterized in that

an electric motor (M3) drives first part of the rear drafting rollers (3, 3’) of the first and third modules (A, C) at the headstock side;
an electric motor (M8) drives first part of the rear drafting rollers (3’’, 3’’’) of the second and fourth modules (B, D) at the endstock side;
an electric motor (M5) drives second parts of the rear drafting rollers (3, 3’, 3’’, 3’’’) of the each module (A, B, C, D);

an electric motor (M2) drives first part of the middle drafting rollers (2, 2’) of the first and third modules (A, C) at the headstock side;
an electric motor (M7) drives first part of the middle drafting rollers (2’’, 2’’’) of the second and fourth modules (B, D) at the endstock side;
an electric motor (M4) drives second parts of the middle drafting rollers (3, 3’, 3’’, 3’’’) of the each module (A, B, C, D);

an electric motor (M1) drives the front drafting rollers (1, 1’) of the first and third modules (A, C) at the headstock side; and
an electric motor (M6) drives the front drafting rollers (1”, 1’’’) of the second and fourth modules (B, D) at the endstock side.

2. The improved drive arrangement as claimed in claim 1 wherein each of the drafting modules (A, B, C, D) further includes a delivery drafting roller (4, 4’, 4’’, 4’’’) driven by the front drafting rollers (1, 1’, 1’’, 1’’’) through gear arrangements (5, 5’, 5’’, 5’’’).

3.The improved drive arrangement as claimed in claim 1 wherein each of the drafting modules (A, B, C, D) further includes delivery drafting rollers (4, 4’) driven by electric motor (M9) at the headstock side and delivery drafting rollers (4”, 4’’’) driven by electric motor (M10) at the endstock side.

4. The improved drive arrangement as claimed in any of the preceding claims wherein the electric motors are servo motors connected to one or more servo drives/frequency convertors.

5. The improved drive arrangement as claimed in claim 4 wherein the servo drives/frequency convertors are connected to a control unit.

6. The improved drive arrangement as claimed in any of the preceding claims, wherein the electric motors are servo motors or induction motors or synchronous motors or asynchronous motors or a combination thereof.

7. The improved drive arrangement as claimed in any of the preceding claims, wherein the drafting rollers are supported at free ends by end bearings mounted on the brackets of machine roller stand.

8. The improved drive arrangement as claimed in any of the preceding claims, wherein the rear (2, 2’, 2”, 2’’’) and middle drafting rollers (3, 3’, 3”, 3’’’) are split into two shafts.

9. The improved drive arrangement as claimed in claim 8, wherein the shafts are split into two equal halves or at any point across the length.

10. The improved drive arrangement as claimed in any of the preceding claims, wherein the modules at the headstock side (A, C) are mirror symmetric arrangement of modules at the endstock side (B, D).