FIELD OF THE INVENTION

The present invention relates to the flat bar of a textile carding machine. Particularly the present invention relates to the flat end connector provided at the both extreme ends of the said flat bar. More particularly this invention is concerned to the end strip provided at the said flat end connector.

BACKGROUND OF THE INVENTION

In textile spinning preparatory machines, the textile fibres have to be opened and cleaned to remove impurities and to be parallelized to convert into sliver. Carding is the heart of textile yarn spinning both with respect to quality and productivity. In addition to the primary functions of removing the trash, neps and non-useful short fibres, the card converts the physical form of the textile material from that of a wide thick feed sheet to that of a thin rope, called Sliver. The linear density of the feed sheet is reduced from about 300-800 grams/meter to about 3-8 grams/meter of delivery sliver. The rollers of various diameters from about 100 mm to 1250 mm and of different surface characteristics of plain to toothed wire covered, run at various speeds and in very close proximity with each other. In many places it is as close as a fraction of a millimeter. The rate of sliver delivery varies from about 40 to 400 meters per minute. The above details indicate how delicate it is to run the machine and handle a thin sheet of individualized fibers called a 'web'. The web is finally condensed into a sliver.

The primary carding action takes place between the Cylinder and Flats. The fibres carried by the cylinder wire tend to move toward the flats that resist fiber movement. Many of the fibres "float" between the flats and the cylinder wire. This carding action separates individual fibres, opens entangled fibres, separates and retains the neps/trash particles in the flats and finally orients the fibers in the direction of the cylinder movement. The setting of the flats with respect to cylinder is extremely important which implies the importance and precision requirements in flats manufacturing.

The flats as used in the revolving flat cotton type carding machine is conventionally usually made as a casting, and essentially comprises clothing section to receive the card clothing tops, a flat end at each end of the flat for sliding engagement on a respective Flexible bend of the carding machine. The conventional flat is prone to certain disadvantages, some of which have become more acute in modern high production carding.

The flats have to with stand considerable bending load due its self weight, and due to the carding action which tends to pull the flat towards the cylinder, since the flat is a beam simply supported at its ends. In order to with stand these inherent and applied loads, the flats has to have large moment of inertia as much as possible with the limitation imposed by machine construction, and this has played major role in the design and manufacture of flats. Considering the requirement of precision and the complexity in processing, flats are made of aluminium extrusions with uniform cross section and end connectors are fitted in the flats ends which form as a sliding member on the flexible bend. This wear sustaining end connectors can be made in different material which has greater wear resistant properties. One such inversion is disclosed in United States patent application 4300266 by THE ENGLISH CARD CLOTHING COMPANY LIMITED. The disadvantage of this invention is that, the replaceable guide shoe, first of all is made from sheet metal and bent to form the required cross section; second it is difficult to mount the strip into the flat, where in the chance of getting damages to the part and the person who makes the assembly. Thus produced guiding shoe in a stamping and bending method does have large manufacturing variation and hence more variation in the flats leading to loss in precision in addition to the complex manufacturing methods.

Attempts have been made to overcome the above mentioned disadvantages through the Indian patent application 4280/CHENP/2007 of MASCHINENFABRIK RIETER AG, in which a detachable plastic strip which is axially pushed in to the mating groove of the end connector is disclosed. The described invention teaches about a guiding shoe which primarily has a spring section for pressing the contact surface on the supporting surface of the flat end head. The spring section has the shape as hook in cross section. This spring force obtained by the elastic deformation of the round hook section, thus avoids the elastic deformation in other sections in particular sliding surface.

The above referred invention has cumulative variations in the assembly of related parts namely 1) Variation from the clothing seating surface to the contact surface on to which the replaceable end shoe is fixed. This variation is due to the, cumulative tolerance effects in Flat body, the end connector and the assembly error of the same. This will induce variation between the carding element and the cylinder wire 2) Manufacturing variation in the inwardly inclined step of the flat head and the corresponding variation in the plastic strip may affect the fitting and lead to inaccuracies. The invention also discusses final machining process to overcome the above manufacturing and assembly cumulative effects of tolerance in the parts involved. In addition the final machining also corrects the undesirable elastic or plastic deformation caused during assembly. This again increases the manufacturing cost of flats and more importantly replacement of the worn guiding shoe is cumbersome.

The applicant's current design uses a carding flat fitted with end connectors on each side made of non ferrous bearing material or single piece polymer material (Fig 1). The end connectors (2) are assembled by forcing in to the flat profile (1) which is extruded., The extrusion process has limitation in dimensional accuracy and the matting section of the end connector will have moulding drafts. This will lead to clearance in fitment and this will be compensated by applying glue in the contact surfaces (3) in fig.2. Subsequently the height (H) in fig. 3 between the clothing seating surface (4) and the sliding surface (5) which seats on Flexible bend of Card will have variation between flat to flat and correction will be done in the sliding surface by milling or grinding by taking reference of the clothing seating surface. By doing this, all the above discussed manufacturing variations will obviate. But this is an additional machining operation. The real problem is that, the machining is required every time while the worn end connector is replaced or to improve the setting accuracy. The invention disclosed in 4280/CHENP/2007 also requires this final machining process, which makes the replacement process very time consuming.

On the view of above said practical difficulties and disadvantages it is posed to bring the following invention to overcome.

OBJECTS OF THE INVENTION

It is an object of the invention to provide an easy to mount and user friendly carding flat end strip.

Another object of the invention is to provide an easy replacement carding flat end strip that fits precisely with flat end head.

Yet another object of the invention is to provide a carding flat end strip with less manufacturing cost and requires no further machining process.

SUMMARY OF THE INVENTION

According to the present invention, the carding flat assembly comprises two replaceable end strips which are coupled to the flat end connectors of a carding flat by means of at least one connecting pin on each side of the flat. So that the said end strip can be positioned precisely in the flat head and hence the final precision of the flats improved without the final machining correction that usually involved in manufacturing of flat. Said end strip is a wear resistant material such as polymer/plastic/rubber/lubrication incorporated material. While replacement or change over the end strip, it is enough to remove the connecting pins and refit again in position. This method of replacement of worn out or damaged end strip is very easy, less time consuming and user-friendly.

BRIEF DESCRIPTION OF THE DRAWING

Figure -1 schematically illustrates the known carding flat bar with end connectors (2).

Figure - 2 shows the side view of flat bar with its inner surface (3) where the glue is applied for fitting the end connector (2) according to known art.

Figure - 3 shows the side view of flat bar with end connector (2), sliding surface (5) and cloth seating surface (4) according to known art.

Figure - 4 schematically illustrates the known carding flat bar provided with end strip according to the invention.

Figure - 5 shows the isometric view carding flat bar provided with end strip according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to the carding machine flat assembly which is schematically represented in Figure - 4 & Figure - 5. The carding flat bar (1) comprises end connector (2) at both extremes but, only a part of side is shown in Figure - 4. Said flat bar (1) further comprises a clothing seating surface (7) where the flat wires to be mounted. The end connector (2) is provided with end head (10). The end connector (2) is made of ferrous/non-ferrous/polymer material according to the invention. . The bottom portion of said end head (10) is further provided with an end strip (12). Lower contact surface (6) at the bottom portion of end head (10) is mated with said end strip (12) by means of connecting pins (9) through the head pin holes (8). This pin hole (8) of the end head (10) extends along the length of the bottom portion as shown. The end connector along with end strip assembly guides along the arc shaped bow (not shown) of carding machine during flats revolution while carding action taking place.

A further detailed view of the of the carding flat assembly according to the invention is shown in the isometric view through Figure - 5 of the drawings. . The end strip (12) comprises surfaces (13) for providing mating joint with lower contact surfaces (6) of end head (10). There are four legs (14) exists in each end strip (12) wherein each of them is provided with strip pin holes (15). The end strip (12) also comprises sliding portions (16) on bottom. Generally these sliding portions (16) are being guided over the arc shaped bow of carding machine during flats revolution. Said end strip (12) is a wear resistant material such as polymer/plastic/rubber/lubrication incorporated material.

During mounting of the end strip (12), all the mating surfaces (13) are being kept in contact with the lower contact surfaces (6) of the end head (10). Then the pin (9) is inserted through the end strip front pin holes (15) and thereof to the head pin holes (8) then into the end strip back pin holes (15). Since the head pin holes (8) and strip pin holes (15) are collinear with each other while mating, the insertion of pin (9) through them is quiet easy and thereby firmly holds the end strip (12) with the end head (10). Moreover by using this pin fastening method, there is an interference of maximum 0.05mm maintained between the lower contact surface (6) of end head and upper mating surface (13) of end strip (12) which ensures the fit by elastic deformation to the tune of maximum 0.05mm . And also the usage of this pin (9) for holding the end strip (12) with the end head (10) confirms that there is no play between them and assure foolproof connection. A relief given in rear side of the leg (14) of the end strip (12) for removing the pin (9) using a special tool (not shown) during disassembly. The whole assembly of end connector (2), end head (10) and end strip (12) are mounted to flat bar (1) in such a way that the mating surface (11) of flat bar (1) is tightly adjoined with end head (10). This is achieved by providing suitable adhesive on the surface of end connector (2) and inserting into the flat bar contact surfaces (3) and additionally by fastening screws through the holes (17). Since the failure of foolproof connection and elastic deformation to large extent in existing art, this invention overcomes those with less effort and simple construction. Requirement of final machining process is nullified by this invention which will lead to simpler replacement of worn end strip at customer place. The embodiments shown herein are only exemplary. Further embodiments are possible within the scope of the invention.

We claim:

1. Flat end connector of a textile carding machine comprises a flat end head (10) having a replaceable end strip (14), wherein said end strip (14) is mounted with the flat end head (10) by means of at least one connecting pin (9).

2. Flat end connector of a textile carding machine as claimed in claim 1, wherein said replaceable end strip (14) has plurality of legs having surfaces (12).

3. Flat end connector of a textile carding machine as claimed in claim 1, wherein said legs are provided with pin holes (15).

4. Flat end connector of a textile carding machine as claimed in claim 1, wherein said replaceable end strip (14) is made of wear resistant material such as polymer/rubber/lubrication incorporated material.

5. Flat end connector of a textile carding machine as claimed in claim 1, wherein said flat end head (10) is provided with pin holes (8).

6. Flat end connector of a textile carding machine as claimed in claim 1, wherein said flat end head (10) is a metallic or non-metallic material.

7. Flat end connector of a textile carding machine as claimed in claim 1, wherein connecting pins (9) are used to hold the end strip (14) with the flat end head (10) through the pin holes (8,15).