Title of Invention	SUCTION TUBE FOR COLLECTING BROKEN ENDS OF FIBERS AT THE OUT LET OF DRAFTING ARRANGEMENT OF A TEXTILE MACHINE
Abstract	The present invention provides a suction tube (1) for collecting broken ends of yarn in suction chamber of a textile or ring spinning machine. The suction tube (1) is constructed with an angular neck portion (1b) and provided with a progressively decreasing inner diameter (D1 & D2)from the suction end towards the collection end for an effective suction of the broken ends.

Full Text

SUCTION TUBE FOR COLLECTING BROKEN ENDS OF FIBERS AT THE OUT LET OF DRAFTING ARRANGEMENT OF A TEXTILE MACHINE Technical Field The present invention relates to textile machines and more particularly to a suction tube of a textile ring-spinning machine, for collecting broken ends of yarn at the front bottom drafting roller zone of drafting arrangement. Background of the Invention The fibers emerging from the drafting arrangement are incorporated with twist by the ring and ring traveler assembly and yarn is formed and wound on the conical tubes fixed on the respective rotating spindles of the Ring spinning and twisting machine and the cop is formed. In the event of the breakage of the yarn, the fibers emerging from the front bottom-drafting roller of the drafting zone are sucked to the suction chamber through the suction tubes. Conventional suction tubes are straight and provided with suction ends with round configuration and positioned beneath the front bottom-drafting roller of the drafting arrangement. Since, suction tubes of straight configurations are used , the broken ends assume about 90° bend while the same being collected by the suction system. Such suction tubes are not effective to suck the broken ends since the suction is not confined to only the path of the yarn, but the air is drawn from all direction in to the opening provided in the suction tube. In order to ensure necessary suction to suck the broken ends from the periphery of the front bottom fluted roller, the conventional system requires substantially greater suction capacity than what would be necessary where the suction is confined to the yarn path and the periphery of the front bottom fluted roller. Means provided for generating such greater suction capacity is very expensive. In most of the cases even with the enhanced suction capacity, the broken ends are not effectively sucked. More over due to ineffective suction the danger of frequent lapping of the broken end on the front bottom fluted roller is always present, which is undesirable. In ring spinning machine majority of breaks of the fiber assembly occur at the twist threshold i.e., in the zone of contact of fiber with the front bottom fluted roller of the drafting system. The force of cohesion in the fiber causes the broken end to adhere to the surface of said front bottom fluted roller and to move along with it. The rotating bottom fluted roller carries the broken end to the immediate vicinity of the plane of the opening present in the suction tube from where it is sucked in to a suction chamber. US patent 4175371 describes a broken end-collecting device for the drafting systems of the spinning machines. The device comprises a suction head for each drafting system connected with an air pressure sink and having a slot-shaped suction opening associated with a delivery or feed roller of each drafting system. US Patent 4825634 describes a suction tube for collecting broken ends of the yarn at the outlet of the textile machine. The suction tube is connected to a collection chamber through a flexible sealing sleeve that permits the suction tube to pivot between its operative and inoperative positions. The suction tube comprises a suction end disposed under the bottom roller of the outlet rollers that has a body portion formed with a suction opening, an opposite end connected to the flexible sealing sleeve and a pair of side walls projecting upwardly from the suction end body portion toward the bottom roller and longitudinally beyond the suction opening on opposite sides of the yarn for confining the suction substantially to the bottom roller and the yarn path. US patent 4845938 describes a means for mounting a suction tube on a textile machine. The suction tube has a suction end and opposite end connected to a collection chamber. A mounting rod is secured to and extends between the mounting stanchions of the machine frame intermediate the collection chamber and the outlet rollers. A support arrangement is mounted on the rod and includes a retaining mechanism for positioning the suction tube and releasably retaining it in an operative position in which the suction end is proximal to the outer rollers and an inoperative position in which the suction end is spaced from the outlet rollers. Objects of the present invention The main object of the present invention is to provide a suction tube for textile ring spinning machine with a suitable suction end profile and an inner diameter to collect broken ends of yarn effectively. Yet another object of the present invention is to provide a suction tube with a broader inner diameter in proximity to the drafting roller and gradually reducing inner diameter at the end portion for effective suction of the broken ends. Another object of the present invention is to provide a suction tube having an angular profile for effective collection of broken ends of yarn. Summary of the invention The present invention provides a suction tube for collecting broken ends of yarn at outlet drafting rollers of drafting arrangement and collecting the broken ends in suction chamber of a textile or ring spinning machine, said suction tube comprising; a suction end disposed beneath the front-bottom end of the outlet drafting roller, and having a hollow and preferably a substantially elliptical opening to provide a guided suction path for collecting the broken ends of the yarn, an angular neck disposed in close proximity to said suction end acting as a funnel, an intermediate straight body extending from the neck and terminating in a relatively narrow end portion, and said narrow end connected to the to the suction chamber. In the present invention, a more effective suction of the broken ends is achieved, since the suction opening of the suction tube is located immediately beneath the front bottom drafting. Further, the suction tube is constructed with progressively decreasing diameter from the suction end towards the collection end to provide more effective suction of the broken ends, since the suction pressure inside the suction tube progressively increases towards the suction chamber. The placement of the suction end of the suction tube disposed under the front bottom drafting roller ensures that the velocity of air in the suction tube is greater than the delivery speed of the fiber from the front bottom fluted roller zone for positive conveyance of the broken ends into the suction tube. Also the suction end of the suction tube is constructed with suitable contour such that the tension force exerted on the fiber strand is not disturbed by the airflow in the suction tube to damage or break the fiber strand being twisted for yarn forming Brief Description of the accompanied drawings Fig 1 partially illustrates the drafting arrangement of a textile machine along with a suction tube of the present invention. Fig 2 is a schematic representation of the suction tube of the present invention depicting its angular shape and the geometry of the inner diameter. Detailed description of the invention Accordingly the present invention provides a suction tube (1) for a textile ring-spinning machine. Now by referring now to the accompanying drawings Fig 1 & 2, the embodiments of the present invention are explained. The drafting arrangement of a textile machine comprises a set front bottom drafting rollers (3). A strand of yarn runs over the front bottom drafting roller (3) before it is wound on a bobbin to form a cop. In an embodiment of the present invention the suction tube (1) of the present invention is disposed just below the bottom of the front drafting roller (3) and the yarn path is generally tangential to the front bottom drafting roller for enabling the suction of broken ends of yarn. The suction tube (1) is fitted to the textile ring spinning machine by means of a holder (5). In another embodiment of the present invention, the suction tube (1) primarily comprises four sectors with variable inner geometrical and outer angle dimensions. The first sector of the suction tube (1) having an opening of suitable profile (la) at one end, said opening (la) disposed in proximity to the front bottom drafting rollers (3). The profile of the opening is substantially elliptical. However, it is understood by a person skilled in the art that other suitable geometrical shapes including rectangular, round, square and triangular shapes can also be suitable adapted to the suction tube of the present invention. The second sectored portion of the suction tube (1) is in the form of a neck (lb), which is in flow communication with the opening (la). The opening (la) and the neck (lb) together form a receptacle or a funnel to provide an effective suctioning of broken ends of the yarn. The neck (lb) having is provided with a uniform wall thickness and with bigger inner diameter. A cylindrical straight body (lc) extending from the neck (lb) acting as a third sector, said third sector terminating in a narrow end (le), thereby constituting fourth sector of the suction tube (1). Accordingly, the suction tube of the present invention is a single unitary structure including above-mentioned sectors for an effective suction of broken parts of the yarn. In yet another embodiment of the present invention, the opening (la) of the suction tube (1) is provided with minor axis (MA) in the range 14-17 mm, preferably 16mm, which is in close proximity to the front bottom drafting roller (3). The neck (lb) of the suction tube is provides with a bend having a radius (R) to provide a curvature for an optimum location of the suction tube opening (le) in proximity to the front end drafting roller (3). The cylindrical straight body (lc), is provided with an increasingly reduced inner diameter from Dl to D2 to appropriately adjust the suction power inside the cylindrical straight body (lc). The angular dimension A between the neck-shaped hollow sector (lb) and the straight body (lc) is in the range of 15-25°, preferably 25°. This angle is optimized to provide an efficient yarn path to enable the opening of the suction tube to suck more effectively the broken ends of the yarn. Further, an angle B is provided between the face of the opening (la) and the straight body (lc), which is in the range 10-20°, preferably 13°. The angle (B) and the radius (R) determine the relative position of the opening (le) of the suction tube with respect to the front drafting roller (3). The fourth sector is in the form of a narrow end (le) with inner diameter (D2). The narrow end (le) of the suction tube is fitted to the suction chamber in a known manner and guided by the tube holder (5) and held at a predetermined location, in coordination with the tube rib (Id) to further prevent the rotary movement of the suction tube during operation. For effective suction, the suction tube is positioned in the machine in a manner such that suction opening (la) is almost parallel to horizontal axis of front bottom drafting roller (3) and kept at a distance of about 0.5 to 1.5 mm to the periphery of said front bottom drafting roller (3). The placement of the suction end (la) of the suction tube (1) with an opening (le) disposed under the front bottom draft roller (3) ensures that the velocity of air in the suction tube (1) is greater than the delivery speed of the yarn from the front bottom drafting roller zone for positive conveyance of the broken ends into the suction tube (1). The suction end (la) of the suction tube (1) is constructed with suitable contour such that the tension force exerted on the yarn strand is not disturbed by the air flow in the suction tube (1) to damage or break the yarn strand being twisted for yarn forming. The angle A and B determines proper positioning of the suction opening of the suction tube with respect to the bottom drafting roller. Plurality of suction tubes (1) and tube holders (5) of equal number as that of the number of spindles are arranged on the ring spinning and twisting machines. Suction tube is constructed with progressively decreasing diameter from the suction end towards the collection end to provide more effective suction of the broken ends, since the suction pressure inside the suction tube progressively increases towards the suction chamber- this is already covered. Advantages 1. In the present invention, a more effective suction of the broken ends is achieved, since the suction opening of the suction tube is located immediately beneath the front bottom fluted roller. 2. The suction tube of the present invention, wherein the suction tube is constructed with progressively decreasing diameter from the suction end towards the collection end to provide more effective suction of the broken ends, since the suction pressure inside the suction tube progressively increases towards the suction chamber. We claim: 1. A suction tube for collecting broken ends of yarn at outlet drafting rollers of drafting arrangement and collecting the broken ends in suction chamber of a textile ring spinning machine, said suction tube comprising; a suction end with a hollow opening disposed beneath the front-bottom drafting roller, to provide a guided suction path for collecting the broken ends of the yarn, an angular neck disposed in close proximity to said suction end acting as a funnel, an intermediate straight body extending from the neck and terminating in a relatively narrow end portion, and said narrow end connected to the suction chamber. 2. The suction tube as claimed in claim 1, wherein the hollow opening is selected from elliptical, square, rectangular, triangular or round shapes, preferably elliptical shape. 3. The suction tube as claimed in claim 1, wherein the face of the opening makes an angle relative to the intermediate straight body is in the range of 10-20°, preferably at 13°. 4. The suction tube as claimed in claim 1, wherein the angle of the angular neck relative to the intermediate body is in the range 15-25°, preferably at 22°. 5. The suction tube as claimed in claim 1, wherein the suction tube having a broader inner diameter in proximity to the drafting roller and having a reduced inner diameter for the straight body and the narrow end. Dated: 28th day of July 2005.

Documents:

745-che-2004 abstract.pdf

745-che-2004 claims granted.pdf

745-che-2004 description (complete) granted.pdf

745-che-2004 drawings.pdf

745-che-2004 form 1.pdf

745-che-2004 form 13.pdf

745-che-2004 form 5.pdf

745-che-2004-abstract.pdf

745-che-2004-claims.pdf

745-che-2004-correspondnece-others.pdf

745-che-2004-correspondnece-po.pdf

745-che-2004-description(complete).pdf

745-che-2004-description(provisional).pdf

745-che-2004-drawings.pdf

745-che-2004-form 1.pdf

745-che-2004-form 18.pdf

745-che-2004-form 26.pdf

745-che-2004-form 3.pdf

745-che-2004-form 5.pdf