DESC:FIELD OF THE INVENTION
The present invention relates to a cleaning arrangement in textile machines and more precisely the invention relates to cleaning stripper for top drafting rollers present in textile spinning preparatory machine such as card, draw frame, comber, lap former and the like.

BACKGROUND OF THE INVENTION
Textile Spinning preparatory machines such as card, draw frame, comber or lap former includes the plurality of pair of drafting rollers. The objective of the drafting unit in such machines is drafting and doubling the fiber strand by way of stretching and make them more parallel, straight and even. Meanwhile this process subsequently reduces the linear density of the said fiber strand to make it suitable for next spinning operation. The drafting unit or drafting zone comprises plurality of pair of top and bottom rollers which are arranged successive to one another. Several configurations of drafting units are known in said preparatory machines such as 4 over 4, 4 over 3 , 3 over 3 and 2 over 2. For example, a 4 over 3 drafting unit meant for 4 top drafting rollers loaded over the 3 bottom drafting rollers.

Drafting action takes place between the two successive pair of drafting rollers when the material passes through. During drafting process, dirty materials and/or loose fiber deposits are accumulated over the surface of top and bottom drafting rollers which affects the quality of fiber strands that are being processed. To eliminate such undesirable quality effect, removal of those accumulated material from the corresponding roller surface is required. This is practically carried out with the help of cleaning strip or scrapper arrangement in said drafting zone. Scrapper/stripper is fixedly arranged in the drafting zone in such a way that the tip of said stripper/scrapper touches on outer surface of each top and bottom drafting rollers. When the roller rotates, the stationary cleaning strip scraps the dirt from the surface of the roller. The dirt then falls off the cleaning strip, and is captured and transported away by the negative air stream of the suction duct provided above and/or below the drafting zone. Such stripper arrangement is already disclosed in DE10207255.

In said arrangement, all the dirt particles are not wiped out or not fully sucked from respective roller surfaces. It has been found that part of the dirt is trapped between the stripper edge and the outer surface of the upper roller. This trapped particles need more attention during cleaning action.

To solve the above problem, a dirt removing device was attempted through an arrangement which is disclosed in patent publication DE102005010769 in which the existing suction duct along with the stripper arrangement is lifted periodically from the drafting roller surface for sucking the struck particles from stripper surface. The stripper device is connected to at least one suction channel wall of the suction device, and at least one wiping device together with at least one of the suction channels of the suction device can be lifted and sunk back. A major disadvantage of the said known device is when lifting the suction duct along with stripper, an increased air circulation passage area is created between roller outer surface and tip of the stripper. Due to this broad void or air passage area, a velocity loss of suction is created. This loss in airflow velocity creates a trouble in sucking action of dirt and fluff of sticky or unscraped material on the top roller surface. This insufficient sucking action results in further staying of said dirt material in between stripper edge and top rollers surface. This causes inefficiency in further cleaning and after some time, more dirt gets accumulated in the trapped area. Since these dirt becomes heavy and hard in nature over the time, the given suction force is not sufficient to suck out this dirt material mass which then falls over the running fibre web due to own weight and gravity. This fallen dirt mass goes along with the processing material and thereby creating undesirable quality issues and thick places. Moreover the prolonged trapping materials affects the service life of both stripper and cot of upper rollers thus leads to uneven fibre web surface as well as roller lapping. Moreover an unwanted machine down time occurs for cleaning and maintenance requirement which thereby creates production loss in textile mills. There has thus been a need to develop a cleaning arrangement for drafting rollers to achieve more production with preferable quality that would overcome the disadvantages present in the existing machines.

OBJECTS OF THE INVENTION
Primary objective of the present invention is to provide an oscillating stripper arrangement which offers efficient cleaning in a textile spinning preparatory machine.

Another objective of the present invention is to provide a centralized stripper position actuation arrangement and adjustment mechanism for cleaning the drafting rollers of textile spinning machine

Yet another objective of present invention is to provide an effective suction arrangement to enhance the quality of sliver web in textile spinning preparatory machine.

SUMMARY OF THE INVENTION
According to the present invention, the textile spinning preparatory machine comprises a drafting zone in which plurality of top rollers and corresponding bottom rollers are provided; a top arm loading arrangement for providing necessary load on the each top rollers with respect to their corresponding bottom rollers; a suction hood extending the entire width of said drafting zone; at least a cleaning stripper assembly for scrapping the top roller surface; wherein a stripper swinging mechanism is provided to adopt at least a cleaning stripper assembly; and an actuating device is provided to drive the said stripper swinging mechanism. The front end of said suction hood opened towards the upper part of the drafting zone whereas the rear end is connected to a suction source of the spinning machine. Said stripper swinging mechanism is operatively hinged to side walls of said suction hood. Thus the stripper swinging mechanism operates without modifying the home position of suction hood and therefore the scrapping action takes place effectively without any suction loss. Said cleaning stripper assembly comprises at least a stripper blade in the form of flexible member made up of polymeric compounds. The stripper swinging mechanism according to the invention comprises plurality of links which can lift-off and lower the stripper blade with respect to top/upper roller surface. The actuating device for driving the stripper swinging mechanism according to the invention is selected from either pneumatic actuator and/or a solenoid actuator and/or electrical actuator and/or prime mover depending upon the requirement.

The primary object of the invention is achieved by lifting/lowering the cleaning stripper assembly alone without disturbing the home position or closed position of suction hood. In a preferred embodiment of the present invention, stripper swinging mechanism comprises a common linkage mechanism which is hinged to suction hood.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure-1 shows the drafting zone of textile spinning preparatory machine according to the present invention.

Figure-2 illustrates the side view of drafting top roller stripper swinging mechanism of textile spinning machine according to the present invention.

Figure-3 shows the isometric view of drafting top roller stripper swinging mechanism along with suction hood of textile spinning machine according to the present invention.

Figure-4 shows the cleaning stripper lifting position of Figure-2.

Figure-5 shows the cleaning stripper lifting position from the Top roller with a distance “X”.

DETAILED DESCRIPTION OF THE INVENTION
According to one of the preferred embodiment of the invention, a drafting zone with 4 over 3 drafting rollers of textile spinning preparatory machine is shown in Figure-1. Said drafting zone comprises 4 top rollers (1,2,3,4) over 3 bottom drafting rollers (5,6,7). These rollers are arranged successive to one another in drafting zone in such a way that the fibre web (8) passes though each pair of rollers. The top drafting rollers (2,3,4) provided with their dedicated cleaning stripper assembly (9,10,11) for cleaning the dirt particles adhered over the peripheral surface of rollers. Said cleaning stripper assembly comprises a stripper blade in the form of a flexible member made up of polymeric compounds. Normally the edge portion of each cleaning stripper assembly (9,10,11) pressingly touches the peripheral surface of top rollers (2,3,4) while said rollers are running.
Figure-2 illustrates the stripper swinging mechanism and its drive arrangement according to present invention. At the time of drafting, the accumulated dirt deposits on the corresponding roller surface in drafting system. These dirt particles are being cleaned or continuously scrapped by the cleaning stripper assembly (9,10,11). A top arm loading arrangement (18) is provided to offer necessary load on to the each top rollers (2,3,4) with respect to their corresponding bottom rollers. Over the drafting rollers assembly, a suction hood (12) is provided which is extended to the entire width of said drafting zone. The front end of said suction hood opened towards the upper part of the drafting zone whereas the rear end (13) is connected to a suction source of the spinning machine. A cleaning stripper swinging mechanism (14) is provided to adopt at least a cleaning stripper assembly (9,10,11). The stripper swinging mechanism (14) according to the invention comprises plurality of links and/or gears (not shown) which can lift-off and lower the stripper blade with respect to top/upper roller surface. Said stripper swinging mechanism (14) is operatively hinged to both side walls present in the front portion of the suction hood (12). The stripper swinging mechanism (14) is operated by a suitable drive or actuating device (15) provided in the bottom portion of the said suction hood (12). The actuating device (15) according to the present invention is selected from either pneumatic actuator or a hydraulic actuator or a solenoid actuator or an electrical actuator or a prime mover depending upon the requirement. Said actuating device (15) is actuated periodically at a predetermined time interval based on dirt accumulation frequency for specific fibre. Said predetermined time interval is programmed and controlled through main controller (not shown) of the textile machine.

Since the stripper assembly (9,10,11) is connected to the actuating device (15) through a swinging mechanism (14) hinged to suction hood (12), only the stripper assembly (9,10,11) is lifted-off and lowered with respect to top rollers (2,3,4) to suck out the trapped dirt particles. At all the time, the suction hood (12) is kept at the home position ie. in closed position. Normally the actuating device (15) is in extended position, to keep the said stripper assembly (9,10,11) in lowered position and therefore the stripper blades touches and scraps their corresponding top/upper roller surface as shown in Figure-2. Whereas while the actuating device (15) contracts, the stripper assembly (9,10,11) is lifted-off and therefore the associated stripper blades also lifted up from their corresponding top roller surface as shown in Figure-4. In this lifted condition, an increased air velocity develops around the edge portion of stripper blades and carry away the trapped dirt particles into suction duct. The Distance “X” between the top rollers and the stripper edge during the lifted condition is maintained as 0.5mm to 20mm, preferably around 3 to 10mm as shown in Figure-5.

In this arrangement, the stripper swinging mechanism (14) operates without modifying the home position of suction hood and therefore no extra air circulation passage area is created between roller surface and tip of the stripper assembly. Therefore the air entry area (16) between top roller’s outer surface and suction hood position remains same at all the time. Hence the scrapping action takes place effectively without any suction loss. Moreover, because of this arrangement, a constant suction velocity is maintained which ensures smooth absorption of trapped dust and dirt into the suction hood from the strippers.

According to Figure-3 of the invention, the stripper swinging mechanism (14) and its mounting arrangement is illustrated as isometric view. Said stripper swinging mechanism (14) comprises plurality of linkage rods as a network which forms a kinematic chain to adopt each stripper assembly (9,10,11). Said plurality of linkage rods along with corresponding stripper assembly (9,10,11) are hinge centered at their respective pivot points (100, 200, 300). The stripper swinging mechanism (14) is operatively hinged to both side walls present in the front portion of the suction hood (12). The stripper assembly (10) of the middle top roller (3) is positioned in such a way that the stripper will be in contact with the middle top roller for all it’s possible nip distance setting. When the middle top roller is moved based on the nip distance setting, the point of contact between the top roller and it’s stripper will change but the stripping action is ensured. This is possible due to the optimized position and length of the middle top roller stripper (10). Thereby a centralized stripper position actuation and adjustment mechanism is integrated to the suction hood (12).

The whole swinging mechanism (14) is connected to at least an actuating device (15) provided in the bottom portion of the suction hood (12) and thus makes the linkages to pivotably operate outside of suction hood (12). To facilitate the opening of suction hood, the rear end (13) of suction hood (12) is pivoted at a hinge point (17) and further connected to a suction source (not shown). While opening the suction hood (12) during maintenance operation, said actuating device (15) along with stripper swinging mechanism (14) goes off altogether with suction hood (12). The stripper swinging mechanism (14) according to the alternate embodiment of the invention may comprise plurality of links and/or chain wheels and/or gears which are suitably connected to respective stripper assembly (9,10,11). The same kind of stripper swinging mechanism and the drive arrangement is additionally or alternatively extended and applicable to bottom drafting rollers (5,6,7) also.

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. It is to be understood that the aspects and embodiment of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiment may be combined together to form a further embodiment of the disclosure.
,CLAIMS:1. A drafting roller cleaning arrangement for a textile spinning preparatory machine, comprising:
a drafting zone comprising a plurality of top rollers (1, 2, 3, 4) and corresponding plurality of bottom rollers (5, 6, 7);
a top arm loading arrangement (18) for providing necessary load on each of said plurality of top rollers (1, 2, 3, 4) with respect to their corresponding bottom rollers (5, 6, 7);
a suction hood (12) having a front end and a rear end and enclosed by a plurality of side walls, extending the entire width of said drafting zone; said front end of said suction hood (12) being opened towards an upper part of the drafting zone and the rear end (13) being connected to a suction source of the spinning machine; and
at least a cleaning stripper assembly (9, 10, 11) for scrapping said plurality of top rollers (2, 3, 4) surface;
wherein a stripper swinging mechanism (14) driven by an actuating device (15) is operably hinged to said plurality of side walls of said suction hood (12), and
wherein the stripper swinging mechanism (14) comprises plurality of links to lift-off and lower said cleaning stripper assembly (9, 10, 11) with respect to said plurality of top rollers (2, 3, 4).

2. The drafting roller cleaning arrangement as claimed in claim 1, wherein said stripper swinging mechanism (14) comprises plurality of gears and/or chain wheels to lift-off and lower said cleaning stripper assembly (9, 10, 11) with respect to said plurality of top rollers (2, 3, 4).

3. The drafting roller cleaning arrangement as claimed in claim 1, wherein said cleaning stripper assembly (9, 10, 11) comprises a stripper blade in the form of a flexible member made up of polymeric compounds and an edge portion of each cleaning stripper assembly (9, 10, 11) pressingly touches the peripheral surface of top rollers (2 ,3, 4) while said rollers are running.

4. The drafting roller cleaning arrangement as claimed in claim 1, wherein the actuating device (15) is selected from either pneumatic actuator or a hydraulic actuator or a solenoid actuator or an electrical actuator or a prime mover depending upon the requirement.

5. The drafting roller cleaning arrangement as claimed in claim 4, wherein said actuating device (15) is adapted to be actuated periodically at a predetermined time interval based on dirt accumulation frequency for specific fibre and said predetermined time interval is programmed and controlled through a main controller of the textile machine.

6. The drafting roller cleaning arrangement as claimed in claim 1, wherein a distance of 0.5mm to 20mm, preferably 3 to 10mm, is maintained between the top rollers (2, 3, 4) and the stripper (9, 10, 11) edge during the lifted condition.

7. The drafting roller cleaning arrangement as claimed in claim 1, wherein said stripper swinging mechanism (14) comprises plurality of linkage rods as a network which forms a kinematic chain to adopt each stripper assembly (9, 10, 11).

8. The drafting roller cleaning arrangement as claimed in claim 7, wherein said plurality of linkage rods along with corresponding stripper assembly (9, 10, 11) are hinge centered at their respective pivot points (100, 200, 300).

9. The drafting roller cleaning arrangement as claimed in claim 1, wherein the stripper assembly (10) of the middle top roller (3) is positioned in such a way that the stripper will be in contact with the middle top roller for all it’s possible nip distance setting.

10. The drafting roller cleaning arrangement as claimed in claim 1, wherein the rear end (13) of suction hood (12) is pivoted at a hinge point (17) and further connected to a suction source.