GB2382355A

GB2382355A - Card clothing

Info

Publication number: GB2382355A
Application number: GB0130213A
Authority: GB
Inventors: Mehul Trivedi; Abhay Dattatraya Hajare; Suresh Shankar Kadu
Original assignee: Indian Card Clothing Co Ltd
Current assignee: Indian Card Clothing Co Ltd
Priority date: 2001-11-21
Filing date: 2001-12-18
Publication date: 2003-05-28
Anticipated expiration: 2021-12-18
Also published as: GB0130213D0; GB2382355B

Abstract

A length of metallic card clothing wire is formed with non-uniform teeth, particularly so that the teeth at the ends of a cylinder are different from those in the middle e.g. to compensate for air currents and give more uniform carding. Adjacent pairs of teeth may have different pitches P or adjacent teeth may have different depths or base, front or back angles or may be of different types. A machine for producing the wire may have individual motors for feeding and punching and a control means to produce varying pitch. It may also have different cutters to produce teeth of different shapes.

Description

Variable Geometry Metallic Card Clothing Wire The present invention is concerned with the geometry of a metallic card clothing wire for use in combination with a card to card cotton.

Conventional metallic card clothing wires are wires formed with an array of similar teeth disposed along their length ready to be wound spirally around a cylindrical organ of a card for carding fibres such as cotton, man made fibres and wool. Figure 1 illustrates a conventional metallic card clothing wire in elevation and section. The wire has distinguishing features including ; the pitch of the teeth, the depth of the teeth, the depth of a tooth base line, the front angle, the back angle and the base angle of the tooth and the type of tooth.

The tooth pitch is the longitudinal distance between similar points of a pair of adjacent teeth on the wire. The depth of the tooth is the distance perpendicular to the longitudinal axis from a tip of the tooth and the point of a cut out between the tooth closest to a rib of the wire. The front angle is the angle made by the front edge of a tooth where it meets the tip, the back angle is the angle made by the back edge of the tooth where it meets the tip. The base angle is the angle made by a root edge of a tooth where it meets the base line. Various common types of tooth are illustrated in figures 2A-2F. The type of tooth describes its profile and includes: Fig 2A landed point tip having a land parallel to the base line behind the tip, Fig 2B cut to point tip, where at the intersection of a front edge and a back edge of the tooth the edges are straight, Fig 2C zero degree cut to point tip having a straight front edge and a CONVEX curved rear edge, Fig 2D curved cut to point tip, where the front and rear edges of the tooth are curved,

Fig 2E diamond point tip, where the back edge is in two portions, a first rising from the base line at a large angle (measured from the rib) and a second straight edge inclined at a lesser angle.

Fig 2F inclined back off point tip, having a straight front edge and a curved back.

Apart from variations within manufacturing tolerances conventional metallic card clothing wire is homogeneous along its entire length with each tooth of similar depth, pitch and type as in fig 1.

Modern high performance cards have cylinder speeds of 600 r. p. m. , such speeds generate significant air currents which have an uncontrolled influence on the carding process. Conventional metallic card clothing wire cannot prevent a fibre being worked on by two teeth of a cylinder simultaneously.

The carding conditions at the axial ends or borders of a carding cylinder are different to those at the middle such that the edge of a web of fibres passing through the carding process is not uniformly carded, the edges being less carded than the centre.

This has an undesirable influence on the quality of the sliver, since the borders of a cotton web cannot be discarded, as is done with a woollen card.

An object of the invention is to alleviate some or all of the aforementioned problems and accordingly there is provided a length of metallic card clothing wire having at least a first tooth, a second tooth and a third tooth and exhibiting at least one of the following distinguishing features: (i) the pitch of the first and second tooth is different to the pitch of the second and third tooth, (ii) the depth of the first tooth is different to the depth of the second tooth, (iii) the type of the first tooth is different to the type of the second tooth, (iv) a base line depth of the first tooth is different to the base line depth of the second tooth (v) a base angle of the first tooth is different to the base angle of the second tooth,

(vi) a front angle of the first tooth is different from a front angle of the second tooth (vii) a back angle of the first tooth IS different to a back angle of the second tooth.

By careful design of the distinguishing features of each tooth of a wire, the wire can be designed to have a favourable influence on the air currents in the carding area of the operating card cylinder. A sequence of tooth depths where a first tooth is separated from the second by a pitch different to the pitch between the second and third tooth may alleviate the problem of a single fibre being worked by two teeth simultaneously The problem of borders may be alleviated by altering the features of the teeth at part lengths of the wire toward each end so that when wound onto a carding cylinder the borders of the cylinder have a different tooth pattern or teeth different from those at the centre.

According to another aspect of the present invention there is provided a machine for punching metallic clothing wire having inhomogeneous distinguishing/characterising features comprising, a CNC controlled draw drive having a first motor, a CNC controlled punching head driven by a second motor and a control unit adapted to synchronise the draw dnve and the punch head to produce and desired tooth pitch in any span of wire as it is drawn through the machine.

Lengths of carding wire embodying the invention will now be described, by way of example only, with reference to the accompanying illustrative drawings, in which: Figure 3 is an elevation of a first metallic card clothing wire embodying the invention, Figure 4 is an elevation of a second metallic card clothing wire embodying the Invention, Figure 5 is an elevation of a third metallic card clothing wire embodying the Invention, Figure 6 is an elevation of a fourth metallic card clothing wire embodying the invention,

Figure 7 is an elevation of a fifth metallic card clothing wire embodying the invention, Figure 8 is a perspective diagrammatic view illustrating a metallic card clothing wire of the invention in combination with a cylindrical organ, like cylinder, doffer, lickerin of a carding machine.

Fig 9 is a diagram of a card clothing wire punching machine according to the invention The metallic card clothing wire illustrated in figure 3 has a cross section similar to that shown in figure 1 and the section is uniform along the length of the wire. In section the wire has a rib 1 of rectangular section. Teeth 2 each of similar type and depth are stamped into the wire at spaced intervals along its length. However, the separation, i. e., the pitch"Pab"between a first tooth 2a and a second tooth 2b is substantially different to the pitch"Pbc"between the subsequent pair of teeth, i. e, the second tooth 2b and third tooth 2c. Each pitch Pab and Pbc is also different to the pitch Pcd between the third tooth 2c and a fourth tooth 2d. This is a deliberate difference and not merely the difference to be found as a consequence of manufacturing tolerances. In this example the difference is of the order of Pab/Pbc = 0.84 and Pbc/Pcd = 1. 34. This difference in tooth pitch may be randomly distributed along the entire length of the wire, alternatively it may be cyclic over any part length of the wire. In particular it may be so distributed that the wire when helically wound onto a carding cylinder or drum C as shown in figure 8 results in the pitch in the border regions R adjacent the ends of the drum being different to the pitch in the middle region M as illustrated by the change in the length of the dashes representing the wire. It will be appreciated that the pitch of the helix is greatly exaggerated in the diagram for the sake of clarity. The carding effect of the cylinder can thus be arranged to be uniform across its entire width (in the axial direction) so that cotton web when carded will be uniformly carded. The number of different tooth pitches

used is not limited to three. Further, although the example shows a distinct discontinuity between the pitches at the junction of the regions R and M, the pitches may change progressively, or once every circumference of the cylinder, to effect a progressive change from the edge of the cylinder to the middle. While this has been explained with reference to the distinguishing feature of tooth pitch any other combination of distinguishing features may be substituted for tooth pitch.

Figure 4 illustrates a second embodiment of the invention. Here a baseline B is shown as a phantom line which passes through the base of each tooth. The depth of the baseline DB is measured from the straight edge 3 of the wire opposite the teeth 2. In this embodiment the depth of the baseline Dba for the first tooth 2a is different to the depth of the baseline DBb for the second tooth 2b. Thus the depth Da of the first tooth is different to the depth of the second tooth Db but the tooth tip depth DT being the distance from the tip to the straight edge 3 remains constant for every tooth 2.

Figure 5 illustrates a third embodiment in which the baseline B has a constant depth DB however, the first tooth 2a has a depth Da different to the depth Db of the second tooth 2b. The tooth pitch and type are constant.

Figure 6 illustrates a fourth embodiment wherein the feature of the base angle a of the first tooth 2a is different to the base angle a* of the second tooth 2b. The features of the pitch, depth front angle ss and back angle f are constant. It may be noted that any of these features may be changed from tooth to tooth. Again there is only a first and second tooth but additional teeth with different features to the first and second teeth may be incorporated in the wire.

Figure 7 illustrates a wire having a first tooth 2a of the landed point tip type, a second tooth 2b is of the cut to point tip type, a third tooth 2c is of the zero degree cut to point tip type a fourth tooth 2d is of the curved cut to point tip type. It will be noted that the base line depth BDd between the third and fourth teeth is increased relative to the rest of the base line depth BDa so relatively reducing the third tooth depth Dd by

comparison with the depth of the other teeth. The fifth tooth 2e is of the diamond point tip type, and the sixth tooth 2f is of the back off point tip type.

Conventionally a machine for forming metallic clothing wire consists of a draw drive to draw a length of wire blank, in the direction of its length through a punching zone and a punch mechanism, mechanically coupled via timing belts and pulleys to the draw drive, whereby the teeth are synchronously punched from the blank. A single motor drive IS provided to power the punch mechanism and the draw mechanism. A single fixed punch head is provided to punch a single type of tooth with a fixed pitch, depth and shape for the entire length of wire.

The present invention further envisages a new machine for punching metallic clothing wire having the distinguishing features of the invention described above and comprising, a CNC controlled draw drive having a first motor, a CNC controlled punching head driven by a second motor and a control unit adapted to synchronise the draw drive and the punch head to produce and desired tooth pitch in any span of wire as It is drawn through the machine.

Further according to the present invention there is provided a machine for punching metallic card clothing wire as defined above and having a punch head with two or more different tooth cutters, each tooth cutter being adapted to cut a tooth of a different shape and capable of being separately selected to a cut a tooth in accordance with control signals form the control unit.

The tooth cutters of the present invention may conveniently be motorised, e. g., driven in rotation or to oscillate whereby the precision and durability of the cutters can be improved An embodiment of a machine wherein the present invention may be incorporate is described hereafter by way of example with reference to the accompanying drawing of figure 9 which shows a machine for punching metallic card clothing wire. The machine compnses a pay off stand 3 consisting of a bobbin of rolled profile blank wire 4. The wire

4 IS drawn from the bobbin 3 by pulling rolls 5 driven at a predetermined rate. The wire than passes to a dancing unit 6 which imposes a constant tension on the wire From the dancing unit 6 the wire is drawn passed a punching head unit 7 by driven draw pulleys 8.

The punched wire is then coiled onto a spooler 9. The speed of the motor driving the driven pulling rolls 5 may be adjusted by a control unit 10 as a long period speed of the wire through the punching head changes, however, short term speed changes are accommodated by the dancer unit which also serves as an accumulator. The speed of the pulling rolls 8 may be varied according to the programming of the control unit 10 by adjusting the speed of an independent motor driving the rolls. This allows the pitch of the wire to be altered without independently of the speed of a punching head 7.

The punching head 7 will consist of at least one tooth punch, and preferably several punches each mounted upon separate heads and able to punch teeth at a rate Independent of the speed of the pulling rolls 8, so that the pitch and type of teeth can be changed according to a control program stored in the control unit 10, without stopping the wire or manually changing the tooth punch.

A non-contact type gauging head (not shown) will preferably be located downstream of the punching head to measure the height of the wire being punched.

A spooler 9 is located downstream of the pulling rolls 8 on to which the punched wire is coiled. The spooler is driven at a steady predetermined rate and its inertia is such that it cannot easily accommodate brief or rapid changes in the speed of the wire being pulled Consequently the machine preferably includes a second dancer/accumulator 6'located between the pulling rolls 8 and the spooler 9 Preferably the spooler 9 has a continuous weighing facility

Claims

1. A length of metallic card clothing wire having at least a first tooth, a second tooth and a third tooth and exhibiting at least one of the following distinguishing features: (i) the pitch of the first and second tooth is different to the pitch of the second and third tooth, (ii) the depth of the first tooth is different to the depth of the second tooth, (iii) the type of the first tooth is different to the type of the second tooth, (iv) a base line depth of the first tooth is different to the base line depth of the second tooth (v) a base angle of the first tooth is different to the base angle of the second tooth, (vi) a front angle of the first tooth is different from a front angle of the second tooth (vii) a back angle of the first tooth is different to a back angle of the second tooth.

2. A length of wire according to claim 1 wherein, over at least a part of the length of the carding wire the teeth exhibit at least one of the distinguishing features of: (i) the pitch between each adjacent tooth is different to the pitch of each other adjacent tooth in the length, or (ii) the depth of each tooth is different to the depth of every other tooth, (iii) the type of each tooth is different to the type of every other tooth, (iv) a base line depth of the each tooth is different to the base line depth of every other tooth, (v) a base angle of the each tooth is different to the base angle of the every other tooth, (vi) a front angle of the each tooth is different from a front angle of the every other tooth

(vil) a back angle of the each tooth is different to a back angle of the every other tooth.

3 A length of wire according to claim 1 or claim 2 in combination with a carding cylinder on which it is wound, wherein the distinguishing features of the teeth of the wire exhibited at each axial end of the carding cylinder are similar to each other but different to the distinguishing feature of the wire wound around the centre portion of the carding cylinder.

4 A length of wire according to claim 3 wherein the distinguishing features change progressively from the axial end of the carding cylinder.

5. A length of wire according to claim 3 wherein the distinguishing features change In steps from the axial end of the carding cylinder.

6. A length of metallic card clothing wire in combination with a cylindrical organ of a carding machine.

7. A length of metallic card clothing wire as herein described with reference to the accompanying illustrative drawings.

8. A machine for punching metallic clothing wire having inhomogeneous distinguishing features according to claim 1 comprising, a CNC controlled draw drive having a first motor, a CNC controlled punching head driven by a second motor and a control unit adapted to synchronise the draw drive and the punch head to produce and desired tooth pitch in any span of wire as it is drawn through the machine.

9. A machine according to claim 8 having a punch head with two or more different tooth cutters, each tooth cutter being adapted to cut a tooth of a different shape and capable of being separately selected to a cut a tooth in accordance with control signals form the control unit.

10. A machine for punching metallic clothing wire having inhomogeneous distinguishing features as herein described.