US3032831A - Carding machine characterized by selfcleaning rotary flats - Google Patents

Description

M y 1962 c. CARMlNATl 3,032,831

CARDING MACHINE CHARACTERIZED BY SELF-CLEANING ROTARY FLATS Filed Sept. 3, 1959 3 Sheets-Sheet 1 Con-Z O C alrminafl'i y 1962 c. CARMlNATl 3,032,831

CARDING MACHINE CHARACTERIZED BY SELF-CLEANING ROTARY FLATS Filed Sept. 5, 1959 3 Sheets-Sheet 2 fxvVEA Tofi' Carlo Carmina-(T May 8, 1962 CARMINAT] 3,032,831

CARDING MACHINE CHARACTERIZED BY SELF-CLEANING ROTARY FLATS Filed Sept. 3, 1959 3 Sheets-Sheet 3 llll||| IA/VE N70 R h C L Ca inafiz' HTTorI YS 3,G32,831 CARDING MACHINE CHARACTERIZED BY SELF- CLEANING ROTARY FLATS Carlo Carminati, Corso di Porta Nnova 3A, Milan, Italy Filed Sept. 3, 1959, Ser. No. 837,836 Claims priority, application Italy Feb. 26, 1959 4 Claims. (Cl. 19-99) The present invention relates to new and novel improvements in carding machines of the type conventionally employing revolving flats in the nature of flat bars which surround the uppermost portion of the peripheral surface of the carding cylinder.

In the carding of textile fibers, conventional carding machines are used for the purpose of disentangling and separating fibers from the tangled state in which they are when new or partially prepared.

In one type of carding machine, the fibers are fed by the licker-in onto the carding cylinder which has a multiplicity of wires or teeth projecting from the clothing surface and the teeth of the clothing catch the fiber and pull and straighten them while gradually separating them. Sets of workers and stripper rolls are disposed adjacent the periphery of the carding cylinder between the lickerin and the dofier for the purpose of exerting a carding action on the fibers. In such operation, a worker roll lifts fibers from the carding cylinder and thereby cards them while a cooperating stripper roll serves to remove the fibers from the teeth of the worker roll and redeliver them to the teeth of the carding cylinder.

In the type of carding machine, to which the present invention is directed, and which is particularly suitable for carding cotton and similar natural or artificial fibers a series of flats are provided instead of the sets of workers and strippers and are disposed over about one-third of the peripheral surface of the carding cylinder between the feed-in area and the doffing area; such flats being in the form of flat bars having teeth or wires extending laterally from one side surface thereof. The flats have a needle or wire-like surface, similar to that of the carding cylinder, and are moved slowly over the surface of the carding cylinder by means of driving chains to which the flats are connected. The flats are held in spaced, parallel relationship and are moved by a suitable driving connection at varying rates of speed. The flats are moved very slowly in the direction of rotation of the carding cylinder and any fibers clinging thereto are intended to be removed by a stripping means, such as a stripping brush.

The carding cylinder turns at a peripheral speed of 35-55 km./hour, and the set of about 100 flats with plane surface, which are connected ringwise by chains and partly lap the surface of the cylinder, shift parallel thereto with very small speed. The cylinder and the flats are equipped with inclined points, which determine the carding action; the fibers transported by the cylinder come into contact with the nearly stand-still points of the flats, and are retained thereby, while contemporaneously they are pulled by the points which cover the cylinder; the fibers are thus subjected to a force tangential to the cylinder and normal to the line of contact of the cylinder with the flats. Due to the carding inclination of the points, such force is decomposable along a carding component normal to the direction of the points, which tends to disentangle the fibers and along the penetrating component parallel to the direction of the points, which tends to make the fiber penetrate and to retain the fibers between said points.

Although it has been attempted to keep the value of the penetratin component within the smallest possible limits suflicient for said purpose, the flats owing to the prolonged contact with the cylinder, become rapidly saturated With fibers, produce waste and favour the formation of neps and of short fibers.

Patented May 8, 1962 ice The function of the flats is to comb the fibers by arranging them in parallel relation. Such carding action is most eflicient at a point near where the fibers are first in contact with the teeth of the flats, due to the fact that, at such point, the teeth are clean. The flats eventually become clogged with waste and perform very little work after a movement of only one third the full extent over the traversed peripheral portion of the carding cylinder. Since the flats must be perfectly clean to perform an efficient and proper work, whereby the fibers will undergo a maximum carding action, it is obvious that only a small number of flats are effectively operating.

In normal operation only less than one-third of the revolving flats are in contact with the teeth of the carding cylinder at one time and only one-third of such engaging flats are effective. This is so since the remaining twothirds of the flats in engagement with the teeth of the carding cylinder are loaded with waste and cannot perform any worthwhile or practical work.

Not only does the loading of the needles of the flats with fibers result in their ineffective operation so as not to be productive of a carding action but, in addition, such loading of the flats forces the fibers down onto the clothing of the carding cylinder and results in the impacting of the fibers. sliver lacking uniformity and having a number of neps therein.

Among the many systems and devices usedto reduce V the loading of the clothing of such plane flats, no system was found better than the slow displacement or movement of the flats along the surface of the carding cylinder, in

- such a manner as to renew periodically the 30-40 flats in carding contact with the cylinder, and to allow cleaning by suitable means. However, with such system, only the first 10-15 active flats are clean and in condition for carrying out an effective carding action, while the others remain loaded and produce the inconveniences and dei loading; the flats being in the form of cylinders and being formed and mounted to rotate about their own long axes.

Thus, it is a further object of the present invention to provide a carding apparatus wherein the carding cylinder has the upper portion of its peripheral surface, between the licker-in and the dofier, encompassed by a plurality of cylindrical members having wire clothing similar to that of the carding cylinder, the members being termed rotary flats and being self-cleaning without the employment of any wiping or stripping mechanism. Because of such self-cleaning characteristic, the rotary flats are free from loading and prevent the formation of neps and short fibers, consequently producing a more uniform sliver without any appreciable waste.

In accordance with the present invention, a carding flat is provided which has a cylindrical surface and is mounted to turn slowly around its own aXis so that in addition to its carding action, it has the characteristic of being selfcleaning. It has been found that to attain the object of self-cleaning, the points of the clothing of each rotary flat, because of the slow progressive movement past the position of tangency with the carding cylinder, should find themselves in a position in which the following two con ditions take place simultaneously:

A. That in such position the distance between the points of the rotary flat and the points of the carding cylinder is still small enough to permit an action of the latter upon the former;

B. That in the same position the inclination of the points of the flats with respect to the surface of the card- This causes the production of a.

3 ing cylinder becomes such that the aforesaid action of the cylinder upon the flats does not cause any carding action anymore but instead causes a cleaning (stripping) of the cover-of the flats.

The important characteristic is believed to be the relation between (1) the angle of the points of the flats in relation to the radius of-the flats and with respect to a tangential line inserted at the point of contact of the points of the carding'cylinder with the points of the rotary flats;

(2) the distance between the points of the cylinder and the'points of the flats in various successive angular positions of the bodies of the flats to the body of the cylinder and, (3') the relative bodily peripheral speedsibetween the flatsand the carding cylinder.

Thus, the present invention provides flats which have a curved surface instead of the conventional planar flats which are in the form of flat bars. The flats of the present invention are preferably in the form of cylindrical members having wire clothing on their peripheral surfaces and the rotary flats are disposed parallel with the carding cylinder and arranged in spaced, parallel relation around the uppermost portion of the peripheral surface of the carding cylinder. Because of the structural arrangement of the points or needles of the rotary flats relative to the radius of the cylindrical bodies of the rotary flats and relative to the points of the carding cylinder and because of the structural and functional interrelationship of the points of the rotary flats and the carding cylinder, including the relative peripheralspeeds thereof, the effect of selfcleaning of the points of the rotary carding flats is realized.

in order to more fully describe the invention, reference will be-made to one embodiment thereof which has been described below and illustrated in the accompanying drawing, such embodimentb'eing merely exemplary.

"In the drawings: i

FIGURE 1 represents diagrammatically one of the possible arrangements of the self-cleaning'flats on a'card for m.

'FIGURE 2 represents a portion of the cylinder surface and a few of the self-cleaningcylindrical flats; i 7

FIGURE 3 is a diagrammatical enlarged representation'of the teeth or points of the cylinder and of the points of the flats with the indication of the forces which determine the self-cleaning of the carding flats;

FIGURES 456 represent afiber and a point of a flat,"in carding position, in neutral position and in selfcleaning position, respectively; and

FIGURE 7 is a diagram of the values of some elements of the card.

"In FIGURE 1 there is shown the lap roll A, the licker-in B, the carding cylinder C having an overall radius including the points or pins indicated by R the dotfer D and the coiler E, such members being part of a conventional carding 'machine. As indicated in larger scale in FIG- URE' Z, the cylinder C, which turns in the direction indicated by the arrow V,,, has a number of the self-cleaning carding flats F disposed about its upper peripheral surface in the zone betwen the licker-in and the dofler. The tips of the points or pins of the flats F are on cylindrical surfaces of radius R and the flats are mounted on convenient supports'which permit bodily adjustment of the flats around the cylinder. Such cylindrical flats rotate around their own axes in the direction contrary'to the direction of rotation of the cylinder, as indicated by the arrow V,, and with very small speed with respect to that ofthecylinder, for example, lower than one hundredth or on the order of one tenth of a thousandth thereof. The individual rotational movement of each rotary flat is so slow that the flats may practically be considered as stationary as far as the action on the fibers is concerned.

The carding cylinder C is provided with the usual clothing having the wire pins or needles radiating therefrom or is otherwise provided with the usual pins or needles, commonly called points. Similarly, the rotary flats have pins onpoints which cooperate in the carding action with the points of the carding cylinder. The points which cover the rotary flats, have a constant inclination on with respect to the radius of the flats and a variable inclination with respect to a tangential line t-t inscribed at the point of confronting relation of the points of the carding cylinder with the points ofthe rotary flats, as indicated in FIG- URE. 3. In FIGURE 3, T indicates the point of a rotary flat in a position of carding contact with the points of the carding cylinder. The force f that stresses the fiber admits a carding component 0 normalto the direction of the point, and a component of penetration p acting in the axial direction of the point and tending to make the fiber enter between the points that cover the rotary flats, as illustrated in FIGURE 4.

A first feature that characterizes the self-cleaning, rotary carding flat, according to the present invention, is that in the position T of a point of the flat, the point is carding. Thus, the inclination admits a component of penetration. Such component of penetration has a value comprised about between one half and one seventh of the value of the carding component. In practice with self-cleaning, rotary carding flats, according to the invention, the angle is comprised bewveen 8 and 30.

The angle formed by a point or a pin with the tangent tt at the place of confronting relation between the cooperating points of the carding cylinder and the rotary flats and, therefore, with the force f, has a value of 0: at T and a value of 90 at T (FIGURE 5), which is displaced along the curved surface by an angle equal to the inclination of the points of the rotary flats. In the position T the force f has a component of penetration equal to zero and, therefore, the fibers cannot penetrate further between the points of the rotary flats (see also FIGURE 5).

If .the point or pin of a rotary flat, having the radius R, is in'the position T which we shall call neutral, the distance d' between said point or pin and the cylindrical surface that envelope the teeth or points of the carding cylinder, having the radius R is'expressed by the relationship.

or, the second term of the second member being negligible in practice owing to the smallness of the ratio Ji /R the distance d may be expressed with suflicient approximation by the formula:

( d=R(l-cos or) The second feature characterizing the self-cleaning, rotary'carding flat, according to the present invention, is that such distance d in the position T where the component of penetration ceases, is smaller thanthe minimum distance at which the points or pins of the carding cylinder C can exert their own action upon the fibers penetrated between the points or pins of'the rotary flats, in such a way that said action be sensible not only in the neutral position T but also, for instance, on a point in successive position T In the discharge position T the force admits a discharging component P in lieu of a penetrating component andsuch component P tends to extract the fibers that have penetrated between the points of a rotary flat, as is clearly illustrated in FIGURE 6. The distance d should be less than 2 mm. in practice (0.080). With+ in such limit the rotary carding flat will also be a selfcleaning, rotary or cylindrical flat.

The carding cylinder C turns around its own axis with a very high peripheral speed and in the direction indicated by the arrow V in FIGURE 3. The force 1 that stresses the fibers, its components 0 and p and, therefore, the carding effect, are maximal if the rotary flats are completely at "a standstill, and becomes nil if the peripheral speeds of the carding cylinder and the rotary flats are equal. Also, the self-cleaning eifect of the rotary flats diminishes, but in greater proportion, as the peripheral speed of the rotary flats increases because the forces which stress the fibers tend to deviate from the tangent to the carding cylinder and to draw near to the tangent to the curved surface of the rotary flats.

The third feature that characterizes the self-cleaning, carding rotary flats is that the carding and self-cleaning capacity of the flats are maximal if each rotary flat turns at a very small speed, namely, if the relative speed between the rotary flats and carding cylinder is nearly equal to the peripheral speed of the cylinder. A rotation of the curved surface of the rotaryflats in a direction contrary to the direction of rotation of the carding cylinder will result in the desired carding and self-cleaning actions of the rotary flats, if the peripheral speed of the rotary flats is small, and lower than, for instance, a hundredth and even one tenth of a thousandth of the peripheral speed of the carding cylinder.

From all that has been stated, it is obvious that the simultaneous existence of the carding effect and of the self-cleaning eifect of the rotary cylindrical flats with curved surfaces, in accordance with the present invention, is related to the co-existence of suitable values of the inclination a, of the distance d and, consequently, with univocal solution (according to Formula 2) of the radius R which limits the action within the stated and set limitations.

For the sake of greater clarity, attention is directed to the diagram of FIGURE 7, in which on the abscissae there are set up the values of the angle a and on the ordinates the values of R in mm. The values of R for d=2 mm. are given by the curve of the diagram.

The field of R and of a that meet the conditions of the present inventtion is confined by the two straight lines H and K corresponding to the values of a=8, and n=30 and by the curve that represents the values R for d=2.0 mm. A further limitation of practical kind is given by the two straight lines of equations R=8 mm. and R=l mm., because on one side it is not possible in practice to construct and support Without inadmissible inflections rolls with clothing inscribed in a diameter smaller than 16 mm., and On the other hand the use of rolls of a diameter larger than 200 mm. would require space and cost beyond reason and cause the disadvantage of too small a number of carding lines. The field of practical utilization of the invention, therefore, is that marked by the hatching.

Within such field in FIGURE 7, there is indicated by cross-hatching a more restricted field, corresponding to cylindrical flats with radii comprised between and 50 mm. which constitutes the field of most practical application of the present invention.

In FIGURE 7, the point Z represents the values adopted with an operating carding machine according to the present invention, which machine has operated with very satisfactory results. In such practical embodiment R=24 mm. and a=13, while d is 0.06 mm. The carding cylinder has a diameter of 700 mm. and turns at the speed of 325-350 revolutions per minute. There are 18 rotary flats which are cylindrical and which rotate about their axes in the opposite direction from the cylinder, with a speed of 0.25 revolution per minute. Each flat is covered with clothing having a saw-tooth wire, providing 345 points or pins per one square inch.

With these actual constructional figures, which are given purely as an example without limitation, a card with selfcleaning, carding rotary flats has been obtained for the first time.

The practical results have been beyond any expectations. As a matter of fact, with respect to a conventional card, the card with self-cleaning carding rotary flats brings about the following advantages: smaller number of neps and impurities in the product at equal output per hour; an improved fibrous diagram owing to the greater number of long fibers and because of the smaller number of broken fibers; savings of raw material up to 3-6% owing to lack of flat strips which are formed by the fibers loaded between the points of conventional flats; higher yield and lower burden of maintenance because it is not necessary to treat the rotary flats in the conventional way as by sharpening and grinding the points; greater simplicity of construction and, therefore, lower cost.

The values of a and of d may vary, within the limits fixed above,-in relationship with the characteristics of the various fibers, such as length, diameter, elasticity, circumvolution, coeflicient of friction, etc., and in relationship also with the characteristics of shape, of friction, and of the number of points or pins covering the selfcleaning carding flats. For any individual type of fiber and for every individual type of flat clothing with the points, it can be determined what are the most convenient values of a and d and, therefore, it can be deduced What is the consequent value of the radius of curvature of the rotary flats.

In practice, the self-cleaning, rotary cylindrical flats, according to the invention, may be built of cylindrical shape but in any case they have their points or pins arranged around a curved surface instead of a plane surface as in the construction of the flat bars forming the conventional flats. The rotary flats are mounted around the carding cylinder but in the zone where normally plane flats are mounted, with their axes parallel to the axis of the cylinder, on supports which permit strict adjustment up to 0.05 mm. (0.002 inch) of the rotary flats with respect to the cylinder, adjacent to one another or with interposed closing members.

The points or pins may be mounted directly on the peripheral surfaces of the cylinders forming the rotary flats or the clothing may be provided with a metallic, textile, synthetic tape equipped with straight or saw-tooth wire points or pins, in order that the inclination u of the points or pins with respect to the radius of curvature of the rotary flats should meet with the above mentioned relationship.

The means of rotating the rotary flats about their axes is not indicated in the drawings because it may be of any conventional construction, with the important characteristic being that of a very low speed of rotation, which is obtainable by convenient ratios of transmission. The rotation may be not only very slow, but also intermittent, because a certain time may elapse before it becomes necessary to clean each point or pin. As far as the carding action or effect is concerned, the rotary flats are practically stationary.

The completely cylindrical shape of the self-cleaning, carding rotary flats with curved surface is the most practical but not the sole possible shape; in fact, it is possible to make carding flats with curved surfaces which shift by means similar to those already described for conventional cards with conventional flats (revolving flat cards), along the surface of the carding cylinder in the direction indicated by the arrow V in FIGURE 3. If there exists the convenientconsistency of the value of the radius of curvature and of the inclination of the points or pins, and if said flats follow-at the point where they leave the surface of the carding cylinder-a curved path with radius equal to the radius of the curvature of the flats, the selfcleaning effect of said flats will be attained.

I claim:

1. In a carding machine, the combination of a carding cylinder horizontally mounted on rotation in one direction about its axis and provided with outwardly projecting carding points having their tips on a common circle and inclined toward the direction of movement of the surface of said cylinder, a plurality of carding flats arranged around the upper portion of the cylinder and disposed on stationary axes parallel to the cylinder, each of said flats comprising a cylindrical body having a cylindrical peripheral surface and a plurality of carding points projecting outwardly from the surface, each flat being rotated about its axis in the direction contrary to the direction of rotation of the cylinder at a peripheral 7, speedwh ich is very low as compared to the peripheral speed of the cylinder, the carding points of each flat being inclined with respect to the corresponding radial direction oppositely to the direction of their movement, whereby the points of each flat have an inclination constant with respect'to the corresponding radius of said cylindrical body but variable in time with respectto said circle of the points of the carding cylinder, each point of said flats having acarding inclination with respect to said circle of the points of the carding cylinder when passing near the cylinder through the plane containing the axes of the cylinder and the flat, a direction perpendicular to said circle in a subsequent position and a discharging inclination opposite to said carding inclination in a still subsequent position, the distance of the tips of the points of each flat from the axis of the flat expressed in millimeters being smaller than 1--cos a a being the angle of inclination of the points of the flats with respect to the radial direction on the flat, and a being comprised between 8 and 30, the distance of the points of each flat from said circle in all of the aforementioned positions being sufliciently smaller as to cause mutual action of the points of the cylinder-and flats, whereby in said last mentioned position the points of the flats are in a stripping or self-cleaning position.

2. The combination of claim 1, characterized in that each fiat is constituted by a cylinder supported rotatably around an axis thereof and driven to rotate with a pe-. ripheral speed lower than one hundredth of the peripheral speed of the carding cylinder.

3. The combination of claim 1, characterized by the diameter of the flats being comprised between 16 and 200 mm.

4. The combination of claim 1, characterized by the diameter of the flats being, comprised between and mm.

References Cited in the file of this patent UNITED STATES PATENTS 1,737,435 Schofield Nov. 26, 1929 FOREIGN PATENTS 665,892 France May 13, 1929 207,429 Great Britain Nov. 29, 1923 769,264' Great Britain Mar. 6, 1957

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