According to one aspect of the present invention a carding element includes a plurality of teeth along an edge, each tooth being at least partly defined by an edge that faces the intended direction of carding and that is inclined rearwardly from the tip of the tooth with respect to the intended direction of carding, the element being characterised in that the depths of recesses formed between at least some adjacent teeth vary along the length of the element.

The depth of the recess between each adjacent pair of teeth may vary. Alternatively, the depth of the recesses between at least some of the adjacent teeth may be substantially identical. For instance, the depth of the recess between at least three adjacent teeth or at least four adjacent teeth may be substantially the same and that depth may a relatively shallow depth.

The element may include a plurality of relatively shallow recesses and a plurality of relatively deep recesses. The depth of each of the relatively shallow recesses may be substantially the same and, alternatively or additionally, the depth of each relatively deep recess may be substantially the same.

The edge that faces the intended direction of carding that defines the relatively deep recess may extend at an angle

to the intended direction of travel of more than 30 or more than 40 or less than 70 or less than 60 or in the region of 50°. The angle of the edge that faces the intended direction of carding that defines a relatively shallow recess may be inclined with respect to the intended direction of carding for each shallow tooth by an angle of more than 50 or more than 60 or more than 70 or less than 85 or less than 80 or in the region of 75°. The edge that faces the direction of carding for the relatively deep recess may be at less of an angle than the angle of the corresponding edge for the deep shallow and may be less than 90% or less than 80% or more than 30% or more than 45% or in the region of 65%.

The rearmost part of a deeper recess with respect to the intended direction of carding may be on substantially the same line as a line perpendicular to the intended direction of carding as the adjacent rearmost point of a trailing shallow recess. The deepest part of a deeper recess may be on substantially the same line that is perpendicular to the intended direction of carding as the deepest part of a trailing shallow recess.

The distance between adjacent teeth may be substantially constant along the extent of the carding element.

The ratio of the depth of the deeper recess to the depth of a shallow recess may be less than 4: 1 or more than 2: 1 or in the region of 3: 1.

The element may be arranged to undergo a change in its angle along an elongate extent of the element, for instance at a mid region of the element.

The present invention also includes a carding member incorporating a plurality of side-by-side carding elements as herein referred to. The elongate extent of each carding element may be arranged to extend in substantially the intended direction of carding or at an angle to the intended direction of carding. Each carding element may be arranged to undergo a change in direction along its elongate extent. That change in direction may be arranged to be at a mid point of each carding element.

The present invention also includes a method of carding using a plurality of carding elements with each carding element being arranged to remove, from a carding fibre cylinder, a greater amount of short fibres from deep recesses in each carding element than in shallow recesses in each carding element with the recesses of the carding element being defined by edges that face in the intended direction of carding and that are inclined rearwardly with respect to the direction of carding.

The method may comprise each carding element having at least two teeth that move through the same line of carding. The method may comprise causing each carding element to include at least two teeth that move in the same line of carding with teeth located between those two teeth carding in a different line. The method may comprise teeth from adjacent carding elements carding in the same line.

The present invention includes any combination of the herein referred to features or limitations.

The present invention can be carried into practice in various ways but one embodiment will now be described, by way of example, and with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of a carding arrangement; Figures 2,3 and 4 are side views of part of different types of carding element ; Figures 5,6, 7 and 8 are side views showing how different carding elements can be attached to a carding member ; Figures 9,10 and 11 are schematic plan views showing the different arrangement that side-by-side carding elements can take in a carding element; Figure 12 is a sectional view from the front of one end of a carding element; Figures 13 and 14 are side views of part of different types of carding element; Figures 15,16 and 17 are end, plan and side views respectively of a further carding element 100; Figure 18 is a schematic view of a manufacturing line for the elements 100; Figure 19 is a side view of a pair of rollers for forming the element 100;

Figure 20 is a side view of a rib mounting orientation different from that shown in Figure 15; Figures 21,22 and 23 are side views of a first element, second element and the first and second elements side-by- side respectively; Figure 24 is a side view showing the elements mounted in a carrier ; Figure 25 is a schematic side view of a carding machine; Figure 26 is a side view showing the relative movement that occurs in a carding action, and Figures 27, 28 and 29 show alternative combinations of the carding element.

As shown in Figure 1, textile fibres are laid onto a rotating cylinder 10 provided with saw tooth clothing 12 from a licker 14. Fibres that have been carded are removed from the cylinder by a rotating doffer 16. Whilst the fibres are travelling around the cylinder 10 they are carded by flats 18 including metallic toothed strips or elements 20. The flats 18 are moved in the same direction as the rotational movement of the cylinder 10 at a slower speed. Consequently the elements 20 remove the short fibres, neps and seed fragments from the fibres on the cylinder 10. A rotating cleansing brush 21 cleans the elements 20 when they have left the surface of the cylinder 10 and the short fibres, seed fragments and neps are taken away through a suction duct 22. The action of

the elements 20 on the fibres remaining on the cylinder serves to align those fibres on the cylinder.

The flats 18 are guided by supporting bends at each side and are driven by a powered roller 26 that drives a chain 28 to which each flat is connected.

Figures 2,3 and 4 show alternative shapes that can be provided to the elements 20.

In Figure 2 the element is provided with alternate deep 30 and shallow 32 recesses between the points 34 of the strip. In Figure 3 two shallow recesses 32 are provided between each deep recess 30 and in Figure 4 three shallow recesses 32 are located between each deep recess 30. In each embodiment the recesses 30 and 32 includes a surface 34 that tapers downwardly and rearwardly with respect to the intended direction of movement 36 of the elements on the trailing side of the recess. A surface 38 on the forward side of each recess also tapers downwardly and rearwardly.

The rearmost portion 40 of the recesses 30 may be located substantially vertically below the rearmost portion 42 of the adjacent trailing recesses 32 (when viewed in the figures, which may be substantially on the same radius of the cylinder 10), and the lowermost part 44 of the recesses 30 may be located in advance of or substantially vertically below the lowermost part 46 of a trailing recess 32. In some instances, the leading part of an element may be located further from the cylinder than the trailing part in what is termed a heel and toe effect.

With this effect, the carding action is greater at the trailing part of the element than at the leading part.

The angle 48 of the deep recess may be, on the trailing edge of the order of 50° to the horizontal and the corresponding angle 50 of the shallow recesses may be of the order of 75°.

In Figure 13 the angle 48 may be of the order of 50°and the angle 50 may be of the order of 70°. The angle of a trailing edge of a shallow recess to the angle of intended direction of travel is of the order of 70° and the angle of the leading edge of the shallow recess 92 is of the order of 32°.

The angle 94 of a leading edge of a deeper recess is of the order of 42°. The radius 96 at the bottom of the deep recesses is of the order of 0.25 mm and the radius 98 at the bottom of the shallow recesses is of the order of 0.15 mm. The spacing between adjacent points along the element is of the order of 1.50 mm.

In Figure 14, the corresponding angles are, for the angle 48, 50°, for the angle 50, 70°, for the angle 92, 31° and for the angle 94, 42°. The radius 96 is 0.31 mm and the radius 98 is 0.25 mm. The spacing between adjacent points along the element is 1.40 mm.

Figures 13 and 14 are side views of part of different types of carding element.

The depth of the deep recess compared to the depth of the shallow recess may be in the ratio of 3: 1.

In use, both the trailing edges of the shallow and deep recesses"attack"the fibres on the cylinder. The short fibres, seed fragments and neps become trapped in the deep recesses. Longer fibres are carded and generally become more aligned on the cylinder.

The exact action is not fully understood in the art. It may be that the long fibres are unable to be trapped by the strips as all that each individual strip is able to do is to push a partially circumferentially aligned long fibre more in line with the circumferential direction. It may be that the short fibres and other contaminants will tend to be less circumferentially aligned with the cylinder 10 and therefore more prone to being trapped by the elements. It may be that the shallow recesses are substantially full of fibres thereby causing the short fibres to enter the deep recesses. It may be that the air current in the deep recesses tend to draw the short fibres into those recesses. It may be that the short fibres tend to be located more radially outwards than the long fibres on the cylinder. Any one of the above possibilities or other factors may cause the short fibres to tend to be located in the deep recesses.

Figures 5,6, 7 and 8 show different ways of fastening the elements 20 to the flats 18. In each embodiment the elements are provided with a lower rib 52 that extends along the length of the element with the ends 54 of the ribs diverging downwardly and outwardly. In each embodiment the elements are slid along a guide 56 which has inwardly and upwardly tapering opposed ends 58 that the ends 54 cooperate with to retain the elements. The

guide also has a base support 60 which the lower side of the ribs 52 cooperate with.

The guide 56 shown in Figure 5 includes a central elongate slot 62 which houses a series of threaded nuts 64 along its length. A bolt 66 extends through a series of openings 68 in a supporting flat 70. Access to the bolts to screw them into the nuts or detach the bolts from the nuts is gained through a series of openings 72 that lead to an elongate channel 74 formed between spaced walls of the flat 70.

In Figure 6 the flat includes bolts 66 located on either side of a central rib 76. The bolts 66 cooperate with threaded openings 78 spaced along a cover plate 80. Each side of the plate 80 cooperates with inwardly facing walls 82 of the guide 56 such that tightening of the bolts causes the plate 80 to bear against the walls 82 to hold the guide against the top of the flat 70.

In Figures 7 and 8, the guide 56 includes elongate recesses 84 along each side in which mounting clips 86 are located. The ends 88 of the clips 86 are bent inwardly towards each other to hold the guide against the flat 70.

Figures 9,10 and 11 show, in plan view, how the elements may be alternately configured as are Figures 27,28 and 29. In Figure 9 the elements extend in a generally circumferential direction. In Figure 10 the elements are at a slight angle to the circumferential direction. In this angled configuration, in the direction of relative movement of the flats and the cylinder, the trailing point of at least one element may pass through the same axial

position as the point of a leading point of an adjacent strip. In Figure 11 the elements are each bent about what may be a central region 89 such that a leading part of the strip is angled in one direction of relative movement and the trailing point is angled in the opposite direction.

In this way the same teeth of angled element may pass through the same circumferential position and it may also be that teeth of adjacent elements will also pass through the same circumferential position.

Figure 12 is a part cross sectional view of an end of a flat showing how one side of an end element 20 is abutted by an angled member 90 to hold the strips in position on the mounting member.

As shown in Figures 15 to 17, in an alternative element 100, includes a base rib 102 with the teeth 105 extending to either side of a centre line, when viewed in plan. The teeth are bent about a deep recess 106 such that, going along the length of the strip, there are two narrow recesses 108 at a first side and then a deep recess defined, at its forward most part, by an edge at that side and then by an edge at the other, second side and then two further shallow recesses to the second side. Figure 15 shows how the teeth of one rib project above an adjacent rib on the first side and over their own rib on the second side.

The embodiments shown in Figures 15 to 17 may have any of the features of the previous embodiments including, for example, the angles.

Figures 18 and 19 illustrate how the elements 100 are formed. Firstly the wire is taken off a roll 110 from where it passes through a punching section. The punching section forms the recesses between the teeth. Then the wire passes between two pairs of driven rollers 112 that deflect the teeth to one or the other side before passing through a heat treatment section 114 before being wound up on a spooler 116.

All of the rollers 112 are driven at the same speed and are coordinated with the speed of supply of the wire. In this way the rib 118 on the roller that extends across the peripheral surface of the roller is able to pass into a similarly extending recess 120 of the other roller with that operation causing the teeth to be bent in opposite directions.

In Figure 20, the teeth extend in a common direction.

However, two elements 122, are mounted side-by-side such that the side surface of the teeth abut each other. To either side of the elements shown in Figure 20 there will be further pairs of back to back elements with the teeth of each pair abutting each other.

As seen in Figures 21 and 22, the teeth of a first element 124 are at a steeper angle of attack in the intended direction of travel than the teeth of element 126. Thus when the elements are located side-by-side they, together, form shallow recesses 128. and deep recesses 130. Whilst the depth of each recess in the elements 124 and 126 are shown as extending to the same extent it will be appreciated that they may have different depths and indeed

the depth of the recess in one or more elements may vary along the length of the element.

Whilst different configurations of deep and shallow recesses have been shown, it will be appreciate that any of the embodiments may have different configurations such as, for example, any combination of one or more depth followed by one or more shallow teeth or, alternatively or additionally, in one or more teeth with a depth between deep and shallow such as a half depth recess. Thus, for example, the element may have, along its length, two shallow recesses, then a half depth recess and then two full depth recesses with that sequence being repeated.

It will also be appreciated that, where the term element has been used it is intended to cover two strips that act together as an element.

Figure 25 shows a carding machine 132. Material is led from a relatively slowly rotating lickerin 134 and is transferred onto a cylinder 136 that rotates very fast.

Then a pair of stripper and worker rolls 138 and 140 (only one such pair being shown) act on the fibres to strip and card the fibres. The stripping roll 138 rotates fast as compared to the worker roll. Instead of or in addition to the stripping and worker rolls, stationary or revolving flats may be used. Finally a slowly rotating doffer roll 142 removes the carded fibre from the cylinder. Figure 25 also shows the direction that the teeth point in with respect to the direction of travel.

Figure 26 illustrates the relative'movement that occurs during stripping with the lower element 144 having its

teeth facing the direction of travel and stripping fibre of the upper element 146 whose teeth face rearwardly with respect to its direction of travel.

It will be appreciated that any of the elements or teeth configuration referred to herein could be used on any carding surface that requires card clothing including, but not limited to rotary drums or cylinders, stationary or revolving flat surfaces or any type of carding machine.

Whilst Figures 9,10 and 11 show parallel, angled and chevron arrangements, Figures 27, 28 and 29 show different arrangements. In Figure 27, the carding is first of all in line with the direction of movement over a length 148 and then at parallel but at an angle to the direction of movement over a length 150. In Figure 28 the carding elements extend over an arc of the same radius with the start and finish of each element being in line with the direction of carding. In Figure 29 the elements are each bent around an arc of a common radius over a section 152 with the remainder of the elements extending in line with the direction of carding which line is also a tangent of the arcs.

The elements may be made from any suitable material such as plastic, which may be reinforced with a ceramic filler, steel which may be hardened and tempered or an alloy steel or a steel with a hard, wear-resistant coating such as ceramic or tungsten carbide.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and

which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least. some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.