Technical field.

The invention is in the field of textiles and particularly relates to carding and f ibre opening machines and to rollers for use in such machines.

Bncl-gQund arJ .

The background art comprises two main groups viz. conventional carding machines hereinafter referred to as the prior art and Robert's specifications US.4,090,276, GB.1,412,109 and GB 1,075,444 which particularly concern the present invention and are hereinafter referred to as the relevant prior art. These latter speci ica ions may briefly be described as providing a carding machine incorporating a train of at least three adjacent co-operating rollers, each roller of which has a first set of effective teeth which are angled forwardly (with respect to the direction of motion) and a second set of effective teeth which are angled rearwardly and which may also incorporate a roller having threaded-on rings of teeth; further, the teeth co-operate in point to point fashion and further, each of the said adjacent rollers in the train runs at a faster surface speed than its predecessor.

In the parts of this specification and claims relating to the present invention, certain words and expressions have special meanings ascribed to them as follows: -

A 'carding machine' is a machine used for the opening of staple fibres and in this specification may include machines used for attenuating, aligning and combing fibres and other related operations.

A 'roller' is a part of a carding machine in which teeth are incorporated. In this specification, when referring to the relevant prior art, the roller is made up in two parts, the core and its separate card clothing which is usually wound on to the core. In one instance, however, the card clothing is

SUBSTITUTE SHEET (ΛULE26)

made up of endless rings which are threaded on to the core.

Two iaportant distinctions between the prior art, the relevant prior art and one preferred fora of the present invention is that in one section of the latter rings of teeth are interleaved and are, for this purpose, secured in precisely predetermined positions on the roller.

In one preferred form of the present invention, a roller consists of a roller bearing means and a special outer part in which the teeth are rooted.

'Special outer part ' is the rigid outer part of a roller used in one preferred fαra of the present invention and is preferably made of steel. It may be integral with the roller bearing means or be a thick metal sleeve which is secured to the roller bearing means.

'Teeth' are projections attached to rollers said teeth acting on the fibres to card, open, attenuate and/or comb them.

'Circumferential' describes a feature in a roller which runs around the circumference of a roller substantially at a right angle to the axis.

'Axial' describes a feature in a roller which runs along the perimeter of a roller substantially in the direction of the axis.

' A ring of teeth' is a circle of teeth at a right angle to the axis of a roller.

'The base of a tooth' in one preferred form of the present invention is that part of a tooth by which it is attached to the special outer part of a roller. Preferably the teeth, the base and the special outer part are integral with each other.

Alternatively, 'The base of a tooth' might include the flexible wire base of metallic wound-on teeth if the said base were integral with the said teeth and, for instance, swaged into jrooves machined in the said special ^■ outer part. The criterion for the said preferred form is that the bases must be secured in predetermined positions in relation to the axis of the roller, nevertheless, in one form of the invention

the base of a tooth is the flexible wire base of wound-on teeth.

An 'angled forward' tooth has an effective leading edge inclined in the direction of rotation.

An 'angled rearward' tooth' has an effective trailing edge inclined in the direction opposite to that of rotation.

An ' orward-rear ard tooth' combines the features of the above teeth and has effective leading and trailing edges.

An 'angled forward-backward facing tooth' is a tooth in which the leading edge is inclined in the direction of rotation and the trailing edge is backward facing but is also inclined in the direction of rotation.

The 'trailing edge' is the backward facing edge of a tooth when the roller is rotating in its normal direction. It is not necessarily 'angled rearwardly' as in the relevant prior art.

The 'height' of a tooth is the distance between its outside edge and its base where it ceases to be effective as a tooth.

A 'blade' is a circumferential edge connecting the points on the trailing and leading edges of a single tooth. '

'Surface teeth' are adapted to card in point to point fashion with teeth in a co-operating roller across a small gap between the outermost parts of said teeth as distinct from interleaved teeth..

'Vound-on teeth' are surface teeth attached spirally by wrapping around a conventional carding machine roller as distinct from being made spirally, for instance by machining, in the special outer part of a roller.

Rings of teeth in the same family* are related to each other by, for instance, there being a regular mathematical connection with rings of teeth on a co-operating roller even though the rings are not necessarily the same distance apart on both rollers. Related teeth may also share a distinctive shape; such rings irs not necessarily the saas height above their base as those on the co-operating roller.

'Swaged' means fixed in position, for instance in a τroov . by an ODβration such as rollinr or hammeriar.

'Rooted' aeans that the base of a teeth is either integral with the special outer part of a roller or is secured in a predetermined position, far instance by swaging in a groove. in the special outer part cf a rolier.

'Co-operating rollers' are adjacent rollers the teeth of which are working on fibres passing between the said rollers.

'Zone of co-operation' means the area between two co-operating rollers where at least some carding takes place.

In this specification the phrase' interleaved rings of teeth* means that such rings have the following characteristics:-

1 Each ring of teeth is secured in the direction of the axis of its roller in a precisely predetermined position relative to a datum point so that rings of teeth on one co-operating roller may rotate and continue to rotate between rings of teeth similarly constructed on an adjacent co-operating roller without interference between the teeth on any co-operating rollers. 2. There is a predetermined distance between the walls of all interleaved teeth so that there is maintained a substantial clearance between the walls of said teeth so that a) there is no scissor action between teeth which could cause fibre breakage and b ⁾ sufficient room is left between teeth to allow carding to proceed smoothly.

A 'lifting surface' is a part of a tooth which is adapted to urge the fibres towards the outside edges of the teeth, to reduce the tendency of fibres to be drawn between the rings of teeth thus reducing fettling and to allow more tolerance in adjustment so that teeth in a succeeding roller can engage the fibres.

A 'tuft' is a small easily carded bunch of fibres.

A 'wad' is a larger bunch of fibres which needs to be broken up before being carded. ???????

Interstices' are small spaces in the component parts cf a roller in which fibres are trapped accidentally.

The 'take-off is the finai removal of the fibres from the doffer.

Disciosure, p inveation

In accordance with the invention. these objects are accomplished by providing a carding machine which includes a train of successive co-operating rollers in which each roller rotates in the opposite direction to and with a surface speed substantially faster than, its predecessor thus causing in said train at least one slower input section and a faster output section, said rollers incorporate teeth which are angled forward in the direction of rotation and teeth which are angled rearward relative to the direction of rotation, and in that at least some of the said teeth an the co-operating rollers incorporate a lifting surface on their leading edges to increase their fibre carrying capacity so that the feed of fibres may be increased to take advantage of the (potentially) faster output of fibres by the faster output section of said train.

The inventuion is developed in that at least some of the teeth on the said rollers incorporate a lifting surface an their trailing edges.

The invention is developed in that there are at least two successive co-operating rollers incorporating interleaved rings of teeth in the said slower input section of the said train, each of said interleaved rings of teeth being precisely secured in the direction of the axis of its roller in a precisely predetermined position relative to a datum point the arrangement being such that rings of teeth on one co¬ operating roller may rotate freely between rings of teeth on adjacent co-operating rollers without interference between the teeth on any co-operating rollers and with a predeteraiaed clearance maintained between the wails of the said tseth.

The invention may be developed in that the said train is in at least three sections, two slower input sections and one

- o - faster output section, the said slower input sections bringing the fibres from the slower entry end cf the said train and both said slower input sections having a substantially similar degree of carding as they converge on each other to meet at a common roller in the body of the said train, the said common roller collecting fibres from the said slower input sections and delivering those fibres to the faster output section, the arrangement being such that the feed of fibres from the slower entry end of said train is substantially balanced by the faster output of fibres at the exit end of said train.

The invention is developed in that at least two co-operating rollers incorporate roller bearing means, a special outer part and rings of teeth with integral bases, the said bases being rooted in the said special outer part of the said roller; in that the said bases are integral with the said special outer part; in that the said rings of teeth are parallel to each other and at ninety degrees to the axes of said rollers.

The inventiuon is developed in that the said train is in at least two sections, a slower input section which includes rollers incorporating interleaved rings of teeth and a faster output section which includes rollers incorporating surface teeth.

The invention is further developed in that the said carding machine includes rollers which incorporate one or more of the following , rings of teeth which each incorporate forward- rearward teeth; in that it includes rollers which incorporate angled forward- ackward facing teeth; in. that the height of the teeth in one said co-operating roller is uniformly less than the height of the teeth in another co-operating roller; in that at least some of the teeth incorporate blades circumferential!'/ connecting the outer edges of said teeth ; and in that some of the said teeth incorporate a lifting surface.

The invention is developed in that, the said carding machine incorporates rollers in which there are no interstices between the bases of rings incorporating teeth.

The invention is developed in that the said carding machine incorporates at least two co-operating rollers on which the distance between interleaved rings of teeth differs; in that at least some of the rings of teeth are offset in relation to the cicuaferential centreline of the said ring; and in that rings cf teeth are offset in relation to the centreline between the rings of teeth on a co-operating roller.

The invention is further developed in that there are made co¬ operating rollers for a carding machine; each said roller incorporating in its said special outer part a plurality of axial grooves along the length of and spaced around the perimeter of the said rollers, said grooves incorporating at least angled forward and aagled rearward facing surfaces. And there being made a plurality of circumferential grooves, said grooves being in precise predetermined positions relative to a datum point. The said circumferential grooves crossing the said axial grooves thus making a multiplicity of rings αf teeth secured in the direction of the axis of each said roller in a precisely predetermined position, each said ring incorporating at least fαrward-rearward teeth integral with the said special outer parts.

The invention is further developed in that in the said special outer part the said teeth are separated by spaces having forward and backward facing edges, the outer part of said edges being the edges αf the said forward-rearward teeth and the inner part of said edges being lifting surfaces adapted to lift fibres from the inner part of the said spaces adjacent the base towards the outer oart of the said teeth.

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The invention is further ieveloped in that carding aachine includes a device to rsmcvs the fibres at hijh speed from the exit end cf the train the said device incorporating a doffer adapted to remove fibres from the previous adjacent co¬ operating roller, a first take-off roller adjacent the doffer and with its surface direction (where adjacent in the same direction as that of the doffer, a second take-off roller adjacent the said first take-off roller and with its surface direction ⁽ where adjacent ^' in the same direction as the said first take-off roiier; further, an automatic means to compress the fibres as they pass between the said first and second take-off rollers may be incorporated preferably on the said second take-off roller and further, at least one air tube is pierced to direct a plurality cf jets of air between the doffer and the said second take-αff roller. A feed conveyor may be provided which will slightly compress the fibres before entry into the slower input section of the said train.

Advantageous Effects..

A carding machine made according to the invention seeks to increase the output cf carding machines relative to their size and weight; to minimize fettling, flying fibres and small entanglements in the wool (naps) and to produce a carding machine in which the fibres flow in a substantially rectilinear manner through the machine to the exit end where the fast flowing fibres are removed at high speed from the dαffer.

Brief iescriptiαn cf the drawings.

Figure i is a graph showing the relationship of distance between co-opera ing rollers and fibres transferred.

Figure 2 is a diagrammatic view of the passage cf a bunch αf fibres between three co-operating rollers, the teeth of which are interleaved according to the invention.

Figure 3 is a diagrammatic side view cf a train of rollers embodying a fora cf the invention.

Figure 4 is a diagrammatic side view cf a train cf roiiers some of which incorporate interleaved teeth and some surface teeth in a form cf the invention.

Figure 5 is a diagrammatic view on an enlarged scale cf a side elevation of fragments of co-operating rollers in which the distance between interleaved rings αf teeth differs..

Figure 6 is a diagrammatic view on a enlarged scale of a side elevation of fragments of rollers 12 and 13 showing rings of interleaved teeth.

Figures 7 and 8 are diagrammatic views of teeth in use in various forms of the invention.

Figure 9 is a diagrammatic view of a rciler with grooves to take interleaved wound-on teeth.

Figure 10 is a diagrammatic section through teeth in Figures 7 and 3.

Figures 12, 13, and 14 illustrate angles referred to in -ae specification.

Figures 15 and 16 illustrate steps in the method of making rollers in accordance with one form ai the invention.

Figure 17 is a diagrammatic view of the take-off assembly.

Figures lδ and 15 are diagrammatic views of an alternative second take-off roller.

Figure 20 is a diagrammatic view o a feed compression assembly.

Xodes for carrying out the invention.

Figure 1 illustrates a problem inherent in known carding machines and paints to a solution. The bottom line 1-2-3-4 indicates in a comparative way, the number of fibres transferred during carding between one co-operating rciiar and another: i indicating many fibres, 2 indicating fewer fibres, 3 indicating still fewer fibres and 4 indicating almost no fibres. The vertical line indicates the clearance between the rollers, 5 being a clearance so large that carding is negligible; 0 being almost nil clearance with good transfer of fibres and good carding; this is the position with ideal point to point conditions between the rollers; 6 is negative clearance i.e. the rollers are interleaved and the transfer of fibres is very good.. The curve 7-0-8 gives an indication of quantity of fibres transferred against clearance.

Little carding is done not only when the clearance 5 is too large even when a proper flow of fibres is available but also when too many fibres are packed into the said too large clearance 5. The same applies when too many fibres are packed into otherwise ideal point to point conditions at 0; the latter feature limits the thickness of fibres which can usefully be fed into the early more slowly rotating rollers

in trains in which succeeding rollers have a progressively faster surface speed than preceding rollers: this leads to a much lesser input than is desirable in this type of machine. A solution is to increase the input beyond the amount possible with conventional carding. This is achieved ia the preferred form of this invention by incorporating rollers with interleaved rings cf teeth and preferably teeth with lifting surfaces.

Fig. 2 illustrates diagramaticaily a train of three co¬ operating rollers 30, 31, and 32 incorporating interleaved rings of teeth in the slower input section of a carding machine made according to the invention.

The arrows indicate the direction αf rotation of the rollers and the increase in number cf arrow-heads indicates that the surface speed of each roller is faster than that cf its predecessor. The rings of teeth of roller 31 are interleaved with the rings of teeth of preceding slower moving roller 30 and also with the rings teeth cf succeeding faster moving roller 32. The rollers have been precisely manufactured according to the invention so that the rings of teeth on each roller will interleave with rings of teeth on related co-operating rollers. This interleaving is similar to the interleaving between the rings cf teeth on rollers 30 and 31 of which teeth 28 and 36 are representative and the rings of teeth on rollers 31 and 32 of which teeth 29, 37 and 38 are representative.

The teeth on roller 30, of which 28 and 36 are examples are integral with its special outer cart 25; the teeth on roller 3i, of which 29 and 38 are exaaplas are integral with its special outer part 26 and the teeth on roller 32, of which tooth 37 is an example are integral the its special c:_ter part 27. There are a plurality of teeth 28 and 36 on ro, er 30, 29 and 38 on roller 31 and 37 on roller 32. As ae

teeth are interleaved they are considered in pairs. The sweep cf the teeth is shown by the dashed lines 33: the small circles 39 represent fibres and a row of small circles 39 represents fibres being carded. The siopes αf the outer part of the teeth and the position αf the small circles relative to the face of the teeth indicate whether the teeth work on the fibres with their front or back faces. and, therefore, whether, in this example, the teeth are angled forward or angled rearward. Interleaving is taking piace where the dashed lines may be presumed to overlap.

Angled forward teeth 29 on roller 21 will pass between, for instance, angled forward teeth 28 and angled rearward teeth 36 on roller 30 taking some of the fibres from teeth 28 on roller 30 to teeth 29 on roller 31. Carding is taking place between the back face σf tooth 36 and the front face of roller 29. Vhen tooth 29 has moved round to be in the zone cf co-operation between the rollers 31 and 32, teeth 29 will pass between angled forward teeth 37 on roller 32. These faster moving teeth 37 will immediately transfer some of the fibres from the angled forward teeth 29 to the adjacent angled rearward teeth 38 on roller 31.

For simplicity, only the active effective function of the teeth has been shown, ignoring a different function of that particular tooth in another part αf the carding operation. Teeth which have two effective functions are shown elsewhere in the specification. Further, the passage will be considered of oniy one substantial bunch of fibres 39 shown as a series of small circles as it is carded by attenuation and opening.

Initially, the bunch of fibres 39 is brought forward on the front faces of angled forward teeth 28 on the slower moving roller 30. As the teeth 28 and 29 pass each other interleaving in the zone cf co-operation between the rollers

30 and 31, the faster moving front faces cf angled forward teeth 29 on roller 31 catch part of the bunch, thus reducing its size, and immediately move it across the small ssace between the front faces of angied forward teeth 28 and the back faces of angled rearward teeth 36 on roller 30.

The remainder of the bunch is carried forward by the faster moving front faces αf teeth 29, the reducing size of the bunch being carded between the slower moving back faces of teeth 36 on roller 30 and the faster moving front faces of teeth 29 on roller 31.

As teeth 29, shown advancing ia four positions, rotate with roller 31 and teeth 36, shown advancing in two positions, rotate with roller 30, the fibres are released automatically in a partially carded state from the back faces of teeth 36 and continue on the front faces of teeth 29 into the zone of co-operation between rollers 31 and 32 The same sequence is followed between rollers 31 and 32. In this case the faster moving front faces αf angled forward teeth 37, shown advancing in three positions on roller 32, pick up the fibres 39 from teeth 29 on roller 31 and immediately transfer some of the fibres from the front faces αf teeth 29 across the small space between the front faces of teeth 29 on roller 31 and the back faces of angled rearward teeth 38 shown advancing in two positions on roller 31.

Carding then continues between the back faces of angied rearward teeth 38 on roller 31 and the front faces of angled forward teeth 37 on roller 32. Additionally, as the faster moving teeth 37 carry some of the fibres past other teeth 38 on the slower rotating roller 31 further carding takes place. The arrangement of interleaved teeth has caused the substantial bunch of initially slow moving and virtually uncarded fibres 39 to flow through the train gradually reducing them in density and increasing taam in speed so

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that they reach the raster output section of the train ia an increasing!v carded rendition. The fibres are thus prepared so that ia due :ourse they will pass through rollers iacαrporatiag surface teeth.

Figure 3 illustrates a diagrammatic side elevation of a train αf co-operating rollers embodying a form of the invention and comprising one faster output section incorporating rollers 49,50,51, a first slower inout section incorporating rollers 46,47.48 with interleaved teeth and a second slower input section incorporating rollers 45, 52, 56 also with interleaved teeth. Without the said second slower input section 45. 52 56 the train comprising six rollers, would be basically similar to a six roller train embodying features of the invention. Assuming the input X from arrow 53 is the maximum that can be carded only X could then be delivered at the exit 55 by the faster output section 49, 50, 51. However, the three rollers 45, 52, 56 make up a second slower input section which brings the input Y from arrow 54 and converges on the said first slower input section to meet at a common roller 49 in the body of the train. The speed cf roller 49 is much increased. Thus the input Y from 54 joins the input X at roller 49 so that the output at 55 = X + Y. By adding three rollers to a six roller train the output at the exit end cf the train is doubled.

Figure 4 illustrates a diagrammatic side elevation of a form of the invention including a train of rollers, comprising one slower input section comprising rollers 40, 41, 42, 43, 44, 72, shown with a double circle and which incorporate interleaved teeth and one faster output section incorporating rollers 73,74,75,76 of which 73, 74, 75 incorporate surface teeth. The height of the interleaved teeth on rollers 40 and 41 is, in this instance, the same but the height of the teeth from roller 41 through rollers

42,43,44, to 72 is gradually reduced as the speed of the rollers increase.At roller 72 the height of the teeth is such that the fibres will transfer from roller 72 tc surface teeth on roller 72. Thereafter the fibres will be further refined through passage through surface teeth.

It is preferred that the rollers 73 and 74 are made to a basic design siailar to that of the rollers incorporating interleaved teeth, but with the height of the teeth and the distance between the rings cf teeth being reduced to become surface teeth. If desired rollers 75 and 76 may be clothed with a modified form of wound-on teeth which will aisc be surface teeth. They will be described later with reference to figure 8. Alternatively, roller 76 may be a doffer or have a doffer immediately associated with it. Other rollers may be added as required. A limitation is speed.

The distance between interleaved rings of teeth and the height αf the teeth must be decided with reference to the thickness αf the fibres. If the distance is too great the carding effect will be negligible, if too little, fibre breakage will be caused. By way of indication and not limitation the distance between rings of teeth on a roller to card wool at the entry end αf a train covered by this specification cculd be 12mm with teeth 6mm high; at the fastest end αf the slower input section the distance between rings cf teeth could be 3mm with teeth 1.5mm high. Vhen carding cotton fibres the figures may be less; with thicker fibres the figures may be more. The diameter of the rollers may be substantially changed. An arrangement of the feed at the entry end 19 and the take-off at the exit end 21 will be described with reference to separata drawings.

Referring now to figure 5, a fragmented enlarged view of parts of rollers 15 and 16 illustrates the case in which the distance between interleaved rings cf teeth differs. The

rings αf teeth 21 which are, as normal ia this specification, spaced along the roiier 15 ia the direction αf its axis, are twice as far apart as the rings of teeth 22 on roiier 16. Rollers 15 and 16 accept fibres in a coarse condition and attenuate and align them as they pass through the zone of co-operation between these rollers. The fibres are then raady for further refining by succeeding rollers. Such rollers would preferably be included in the slower input section of a train.

A further feature αf the invention is illustrated in figure 5 in which the teeth 22 on roller 16 are slightly offset in relation to the centre-line 23 between the rings of teeth 21 on co-operating roller 15. Such an offset may be varied at succeeding rollers to blend the fibres. The essential clearance between the walls of the teeth is shown at 95.

Referring to figures 4 and 6, typical rollers 42 and 43 illustrate in diagrammatic fragmented view interleaved rings of teeth 9 and 14 in yet another feature of the invention. The height 10 of the teeth 9 on one co-operating roller 43 is uniformly less than the height 11 of the teeth 14 on roller 42. 3y gradually reducing the height of the teeth an succeeding rollers, preferably combined with lifting surfaces, the fibres are brought closer to the surface αf succeeding rollers in the train so that eventually the fibres will readily pass to rollers adapted to carry fibres on surface teeth.

Moreover, it is essential that the rings cf teeth 5 on roiier 43 are secured in the direction αf the axis of the roller 43 in a precisely predetermined position in relation to a datum point 150 an roiier 43. It is equally essential that the completed rings of teeth 14 on roller 42 are secured in the direction of the axis αf roller 42 in a precisely predetermined position in relation to a datum

V

point 151 on roller 42. It is also important that the datum points on each roller should be maintained in relation to each other during the manufacture of the machine. The same remarks apply to all interleaved rings of teeth on this type of machine. As the rings of teeth 9 and 14 are integral with the special outer part of the rollers 43 and 42 there are no Interstices adjacent the bases of the rings of teeth and the special outer part of the rollers 43 and 42.

Referring now to figures 4, 7, β, 9, 12, 13, 14. In figures 7 and 8 teeth are illustrated which have some similar relationships in accordance with the invention, The teeth are shown in profile. The normal direction of rotation of the rollers to which the teeth are attached is shown by the arrow 127 at the lower part of each diagram. The bases 124, 125 and 126 are, in practice, tangents to the circumference.

The teeth in figures 7 and 8 are integral with the special outer part of the roller but similar teeth may be integral with or otherwise firmly attached to the base which forms part of the flexible wire base of wound-on teeth as shown in section in figure 10; short lengths of such teeth can be swaged as shown at 146 into parallel grooves 147 cut at predetermined distances from the datum point 149 along a roller in the direction of its axis and be interleaved or, in a much smaller size, be wound-on without grooves in the conventional manner to be used as surface teeth.

The teeth in figure 7 have an angled forward leading edge 118 inclined at an angle 128 (figures 7 and 12) in the direction of rotation and, in this case, a much smaller trailing edge 119 Inclined at an angle 129 (figures 7 and 13) in the direction opposite to rotation. In this instance, angle 128 would be about 60 degrees and angle 129 about 75 degrees. This combination would form forward-rearward teeth. Also shown are lifting surfaces 112 and 115. these teeth

are currently preferred for rollers in the slower input section of a train.

The teeth in figure 8 have an angled forward leading edge 120 inclined at an angle 128 In the direction of rotation and a backward facing trailing edge 121 inclined at an angle 130 also in the direction of rotation. These are angled forward-backward facing teeth according to the invention. In this instance the angle 128 would be fifty five degrees amd angle 130 would be about one hundred degrees. This arrangement allows the fibres to be attenuated and opened but with a less retarding effect than when the angle 130 is 90 degrees or less. The criterion is that the angle (in this instance 55 degrees) of the leading edge must be substantially less than the complementary angle (80 degrees) to the angle (in this instance 100 degrees) of the angled forward backward facing trailing edge, otherwise no carding can take place.The angles quoted are by way of indication and not limitation.

Lifting surfaces 112, 113, 115 and 116 may be provided; it will be noticed that because part of tooth 121 is angled forward it is itself a lifting surface. The reasons for the lifting surfaces are a) to urge the fibres on the teeth towards the outside edges of the teeth; b) to reduce the tendency of fibres to be drawn between the rings of teeth by faster moving teeth on a co-operating roller and c) to allow more tolerance in adjustment so that teeth in a succeeding roller can engage the fibres.

Referring now to figures 6, 7, 8, 15 and 16, the teeth In figures 7, 8 and 15 are typical of those used in the rings of teeth 9 and 14 -in Figure 6 and 92 in figure 16. Such teeth in some cases incorporate an angled forward leading edge 118 with an angled rearward lifting surface 115. Similar teeth in some cases incorporate, for example, an

angled rearward trailing edge 119 with an angled forward lifting surface 112.

Referring to figures 15 and 16, there is now described a method of making a roller suitable for co-operating v/ith other rollers in a carding machine made according to the invention. Λ steel roller 79 has its special outer part 81 sleeved on to its roller bearing means 80; the dotted lines on figures 15 and 16 give an indication of the joint line.

Using a dividing head, a plurality of axial grooves 87 amd 88 are milled lengthwise along the roller in the said special outer part with cutters 83 and 84 which are offset in relation to the centreline 82 of the said roller 79. The shaped cutter 83, correctly offset to the right of the centreline, will produce a backward facing surface 86 (if the roller Is rotating in the direction shown by the arrow 98) with a lifting surface 89. Vith the same direction of rotation the shaped cutter 84, correctly offset to the left of the centerline will produce an angled forward surface 93 with a lifting surface 90.

When the axial grooves 87 and 88 are amalgamated, (as shown by the dotted line adjacent to groove 88) by continued revolution of the dividing head, the grooves will be shaped as shown at 85.

Further, there is machined, along the length of the roller, a plurality of circumferential grooves 91, said grooves being in precise predetermined positions relative to a datum point 96, for instance, the end of the special outer part 81 of the roller 79. The said circumferential grooves 91 cut across the said amalgamated axial grooves 85 thus making a multiplicity of rings of teeth 92, secured in the direction of the axis αf its roller in a precisely predetermined

posi ion each said ring incorporating forward-rearward teeth 97 integral with the said special outer part 81.

If more teeth are required in a roller of the same diameter smaller teeth must be made; larger diameter rollers may be made to Incorporate more teeth or larger teeth but fibre length is a factor to be considered. By changing the angles on the cutters 03 and 84 teeth may be made to meet different requirements to be served by the invention.

A cutter similar to cutter 83 but offset slightly to the left of the centre line 62 is used, when necessary, to produce angled forward backward facing teeth integral with the special outer part as distinct from as metallic wire wound-on to a plain roller. Proper arrangements are made to assemble a train σf carding machine co-operating rollers made in the above manner. The rings of teeth on the said rollers will interleave without any interference.

Referring now to figure 17, the roller 76 in figure 4 is now shown as a doffer 152 rotating in the direction of its arrow and with angled rearwardly teeth 155.

A first take-αff roller 153 has a plain surface preferably polished, is adjacent to, has its surface direction (where adjacent) in the same direction as and preferably has its surface speed slightly faster than, the doffer 152,

A second take-off roller 154 also has a plain surface preferably polished, is adjacent to, has its surface direction (where adjacent ⁾ in the same direction as and has a substantially similar surface speed to, the said first take-off roller 153. The single headed arrows show the relative directions of the rollers 152, 153 and 154.

An air tube 156 is pierced to direct a plurality of jets of air betwen the doffer 152 and the said second take-off rollei 154 and between the rollers 153 and 154. The fibres are urged by the air between rollers 153 and 154. The clearances between the doffer 152 and the roller 1 4 ami the rollers 153 and 154 may be fixed or adjusted by automa ir means such as springs, especially If the rollers 153 and 154 nre positioned beneath the doffer 152 to take advantage of gravity to clear the fibres. Such an automatic adjustment may be substantially in the directions of the double headed arrow 138.

By way of indication and not limitation the clearance between the doffer 152 and the first take-off roller 153 is less than one millimetre, the clearance between the doffer 152 and the second take-off roller 154 is between four and six millimetres and the clearance between the first take-off roller 153 and the second take-off roller 154 is four millimetres. If required, a second air tube 157 may be pierced to allow a plurality of jets of air to play on the surface of the said first take-off roller 153 to prevent the fibres encircling the roller 153. The air jets are shown by arrowed lines directly connected to the circle representing the air tubes 156 and 157.

Referring now to figures 18 and 19, in an alternative method of making the second take-off roller ⁽ here called 158) a series of rings 159 are made along the length of the roller in the direction of its axis.

Referring now to figure 20. It is permissable In a carding machine made according to this invention that fibres may be compressed into the rollers incorporating interleaved teeth. Rollers 140 and 141 represent rollers 10 and 11 in the train shown in figure 4. The feed conveyor 142 brings the fibres in uncarded condition; the small idler rollers 144 which may

be made of nylon, stroke the fibres into an approximately level surface. It is desirable that the fibres should not be rolled; to this end a compressor conveyor 143 travels at substantially the same speed as the feed conveyor 142 and the roller 140. As the fibres approach the rollers 140 and 141 they are gently compressed thus increasing the feed of fibres into the slower entry end of the carding machine.

By way of indication but not limitation the diameter of the rollers 30,31,32 In figure 2, and rollers 40,41,42,43 in figure 4 used in the prototype machine which has been used as a guide for this specification is about ten centimetres; the interleaved teeth gradually reduce in height from about 4.5mra on roller 40. The roller 152 on figure 17 is about 200mm; rollers 153 and 154 are about 50mm.

The first roller at the entry end of a train of eleven rollers could be 6 r.p.m. and the last roller 750 r.p.m. Different diameter rollers and different speeds between co¬ operating rollers and dfferent heights of interleaved teeth are factors which may, with advantage, be changed to suit the length and characteristics of the fibres being carded. It is desirable that all the teeth be hardened and tempered.

It is preferred that the speeds of rollers should be independently adjustable so that the passage σf the fibres may be adjusted to obtain the maximum output from the machine. It is also preferred that at least the first pair of rollers (for example those shown at 40 and 41 on figure 4) should be provided with a safety device in case a foreign body attempts to enter the machine.

Industrial applicability.

The invention seeks to improve the overall efficiency of carding machines.