US2175107A

US2175107A - Mechanism for drawing textile rovings

Info

Publication number: US2175107A
Application number: US203415A
Authority: US
Inventors: Casablancas Fernando
Original assignee: Casablancas High Draft Co Ltd
Current assignee: Casablancas High Draft Co Ltd
Priority date: 1937-12-06
Filing date: 1938-04-21
Publication date: 1939-10-03
Anticipated expiration: 1956-10-03
Also published as: GB493180A; FR841939A

Description

Oct. 3, 1939. F. cAsABLANcAs IEGHANISM FOR DRAWING TEXTILE ROVINGS Filed April 2l, 1958 2 Sheets-Sheet 1 Oct. 3, 1939, F. cAsABLANcAs 2,175,107

IBCHANISM FOR DRAWING TEXTILE ROVINGS Filed April 2l, 1938 2 Sheets-Sheet 2 Patented Oct. 3, 1939 PATENT cri-ICE MECHANISM FOR DRAWING TEXTILE ROVIN Manchester, England, as-

Fernando Casablancas,

sign

or to Casablancas High Draft Co., Ltd.,

Manchester, England, an English company Application April 21, 1938, Serial No. 203,415 In Great Britain December 6, 1937 9 Claims.

This invention relates to mechanisms for drawing textile rovings or slivers and more particularly to high draft mechanisms making use of one or more endless belts, and one of its chief objects is to overcome certain objections and limitations which are inherent in mechanisms of this type as at present known and used.

Other objects will be hereinafter set forth and will be apparent from the following description l0 taken in conjunction with the accompanying drawings in which:

Figure 1 illustrates diagrammatically and in section a typical two-belt arrangement of the known and widely used mechanism of the socalled Casablancas system;

Figures 2 and 3 are similar views showing this known mechanism in faulty operation;

Figure 4 shows diagrammatically and in section an improved mechanism in accordance with the present invention, and l Figures 5 to 10 show various modifications according to the invention.

The endless belts of the mechanism shown in Figure.. l give better results than the older method of drafting by rollers only, for the following three main reasons:

(a) The delivery nip N at the front part of the belts I and 2 is set nearer the nip of the drawing rollers 3 and 4 than is possible with a pair of rollers of a practical diameter.

(b) The delivery nip formed by the two belts controls the libres more effectively than would a pair of rollers, on account of the softness of the belts and also of their surface of contact acting on the fibres over a distance preceding the actual delivery nip of the belts.

(c) The fibre-carrying belts are positively driven by means of a pair of rollers 5 and 6, the nip between which is set at a distance from the nip of the front drawing rollers 3 and 4 sufficiently great for the spinning of the longest cotton fibres.

The standard belt arrangement illustrated in Figure 1 may be said to comply with each one of the three points (a), (b) and (c) as much as is possible with this type of mechanism. In actual practice, the closeness of the nip N to the rollers 3 and 4, the softness of the belts, and the separation of the rollers 5 and 6 from the rollers 3 and 4 are factors restricted to certain definite limits` beyond which the arrangement would begin to work in a very unsatisfactory manner. Therefore the scope and the efficiency of present belt mechanisms is directly dependent on the degree to which the three conditions (a), (b) and (c) can be achieved.

The two endless belts l and 2 are set almost touching the front rollers 3 and 4 as shown in Figure 1, the distance between the nip N and the 3 drawing nip of the rollers 3 and 4 being, therefore, the minimum possible with this present arrangement. A nearer nip N could be obtained if the two belts were forced to bend more sharply round the arms of the tensor 1, 8 but, with belts I'10 of the usual thickness and rigidity, this would result in excessive friction against the arms of the tensor and also in excessive tightness on the bres within the nip N. Thinner or otherwise softer belts would give a satisfactory nearer nip 15 N, but these cannot be used because, in practice, they would not work properly over the space between the rollers 5 and 6 and up to the nip N, that is, over the portion which is utilised for the control of the fibres. Owing to the fact that the 20 middle parts of the belts are being pushed along from the rollers 5 and 6 towards the front nip N, they will only travel straight along the desired path if each belt is sufficiently rigid and the opening between the two arms of the tensor 1, 8 is 25 I sufficiently wide.

In addition to these two conditions the length of belt comprised between the rollers 5 and 6 and the nip N must also be sufliciently small. If this is too great, the belts too thin or soft, or the opening of the tensor too narrow, the belts will be deformed out of their straight paths in, for example, the manner shown in Figure 2 or Figure 3.

When this occurs the results are very unsatisfactory and irregularities in the drafting opera- 35 tion are inevitable. The belts in the position shown in Figure 2 will eiect a greatly increased control over the fibres, which are gripped between the belts immediately before the delivery nip N; whereas the position illustrated in Figure 3 will 40 give much less control at the actual nip N and no control at all before it.

It is therefore an object of the present invention to surmount the above-mentioned limitations in a practical manner by means of a draw- 45 ing mechanism in which:

(a) The distance between the delivery nip of the belts and the drawing nip of the front rollers can be smaller than heretofore.

(b) The belts themselves can beI made of a 50 thinner and softer material..

(c) The rollers carrying the belts can be set at a greater distance from the drawing rollers.

It is clear that a mechanism having these three main advantages will be able not only to draw all 55 n endless belts I0, II, I2

propelling element.

u would only increase 55 rollers 3 005and6 65 of rollers 5 and 6 be applied in a kinds of cotton fibres more satisfactorily than the previously known mechanisms, but that it will also be able to deal with those special bres which are either too short or too long for satisfactory 5 treatment with the mechanisms known heretom ing use of one or more endless belts to guide and control the roving, at least one additional belt which supports and guides the outer roving-conf trolling belt along the path of the roving and ensures a sumcient firmness of grip between this u belt and the belt or other means which co-operates therewith to guide and control the roving.

Figure 4 shows one such mechanism provided with endless belts in accordance with the invention. The two rollers 5 and 6 each carry four and I3 and 20, 2|, 22, 23 respectively. Of these, the, pair I and 20 are the only two acting on the fibres; each other additional belt is smaller than the preceding one and acts over its inner surface as a steadying and Without the collaboration of the inner belts II, I2 and I3 and 2|, 22, and 23, the outer belts I0 and 20 would not be able to follow a straight path from the rollers and 6 to the nip N nor would they maintain a steady n contact pressure or grip over the full distance.

The pressure between the two working surfaces of the belts would be at its maximum under the rollers 5 and 6 but would soon decrease to nil or almost nil along most of the distance and again near the nip N.

0n the other hand by the use of the inner belts as in the illustration, the outer belts III and are effectively assisted in their movement from the rollers to the front nip N and they are not allowed to be deflected or become slack. Fur

thermore, the pressure or grip on the libres at N is maintained practically constant over the full distance between the rollers 5 and 6 and the nip N. It may also be so arranged that the dl pressure decreases gradually and uniformly from a maximum between the rollers 5 and 6 to a minimum at N, the desired result being obtainable in diierent ways such as by the use of inner belts of varying thickness or rigidity.

In Besides the steadier and improved fibre control which this mechanism gives were the roving is held between the belts from the rollers 5 and 6 to the nip N, it will be observed that the nip N is now much nearer to the front drawing and I and this is a fact of paramount importance in the treatment of the shorter fibres such as Indian cotton and ,waste iibres of various kinds. Furthermore, since long soft belts It and 20 can be used with the driving rollers very far from the drawing rollers 3 and 4,-exceptionally long bres such as wool, cut rayon, etc. can be successfully worked.

Most important of all is the advantage that, as the large distance between the positive nips and 3 and l is obtained together with the very short distance between nip N and the rollers 3 and l very short and very long fibres may be treated at the same time; in other words, the mechanism is eminently suc- 70 cessful in the drawing of mixtures of very different textile iibres to produce yarns with special eifects or qualities, for which there is an increasing demand at the present time.

'Ihe principle of the invention as described may variety of other ways some of which are illustrated in Figures 5 to 10 of the accompanying drawings.

Figure 5 shows an arrangement in which the inner belts II, I2 and 2|, 22 are made to pass round rods or rollers I4, I5 and 24,` 25 which are placed in suitable positions to increase or decrease the pressure of the belts III and 20 on the roving.

In Figure 6 the arrangement is similar to that of Figure 5 but the inner belts II, I2 and 2i, 22 are pressed towards the roving by means of suitable cross-pieces or plates I6, Il and 26, 21.

Figure 7 represents a belt arrangement with no tensors and using instead two outside plates I8 and 2l which squeeze the belts into a very acute front nip N. This particular example again clearly illustrates the part played by the inner belts II, I2 and 2|, 22, without which the narrow and very sharp front nip formed by the outer belts Il and 2l would be quite unobtainable.

Figure 8 shows an arrangement with inner belts mounted inside only one of the main belts. The inner belt II in the illustration presses the outer belt I0 against the bottom belt 20 and, although owing to the slack of this bottom belt the path of the roving is deflected as shown, the contact between the working surfaces of the top and bottom belts is kept rm and steady owing to the resilient action of the inner belt. A fixed member I6 is shown bearing against the upper side of the belt II.

bottom belt 20 is held cal means such tensioning lever taut by suitable mechanias, for instance, a small pivoted 3U and weight 3l, so that the top main belt III which is provided with two inner belts II and I2 is held in contact along a substantially straight path.

The application of the inner the ways described, can also be carried out in the case of drawing arrangements, with only one acting belt and a stationary plate, or with one belt and one roller, or with one belt and a plate and a roller. TheI single acting belt can then be provided with one or more assisting belts inside it.

The last mentioned arrangement is shown in Figure 10 which shows a drawing mechanism having a fixed plate 32 and additional roller 33 which cooperate with the belt I II to guide and control the roving. Additional belts II and I2 are provided within the belt III.

In all the examples described and in the various possible alternative combinations embodying the principle of this invention, the inner belt or belts may be narrower than the outer belts acting on the roving, and two or more narrow inner belts of the same length may be used side by side in lieu of a single wider belt. Furthermore, the roller or rollers carrying the belts may have suitable recesses or grooves for the inner belts to fit in, so that they do not project above the surfaces of the rollers.

What I claim and desire to secure by Letters Patent of the United States is:

l. In a mechanism for drawing textile rovings the combination of two rollersl at leasttwo endless belts one within the other passing round each of the said rollers, each belt forming a loop extending from its roller and the outermost belts being adapted to guide and control the roving being drawn, tensor means within the loop of each outermost belt and means engaging the outer surface of the loop of at least one of the belts in )any of inner belts to increase the pressure exerted on the roving.

2. In a mechanism for drawing textile rovings the combination of a roller, at least two endless belts one within the other passing round the said roller and extending therefrom in the form of loops, a tensor member within the loop of the outermost of the said belts, means co-operating with one side ofthe loop of the said outermost belt to guide and control the roving being drawn, means engaging at least one of the inner belts within the loop thereof for modifying the pressure between the outermost belt and the co-operating means, and means for drawing the roving from between the said outermost belt and the said cooperating means.

3. In a mechanism for drawing textile rovings the combination of a roller, at least two endless belts one within the other passing round the said roller and extending therefrom in the form of loops, a tensor member within the loop of the outermost of the said belts, means co-operating with one side of the loop of the said outermost belt to guide and control the roving being drawn, means engaging the outer surface of the loop part of at least one of the inner belts for increasing the pressure between the outermost belt and the cooperating means, and means for drawing the roving from between the said outermost belt and the said co-operating means.

4. In a mechanism for drawing textile rovings, the combination of a roller, an endless belt passing round said roller and forming a loop extending therefrom, means cooperating with the said belt to engage and guide the roving being drawn, at least one additional endless belt within the rst mentioned endless belt and passing round said roller, said additional endless belt being adapted to support and guide said first mentioned belt, and means for drawing the roving from between said first mentioned belt and said cooperating means.

5. In a mechanism for drawing textileA rovings, the combination of a pair of rollers, an endless belt passing round each of the said roller each belt forming a loop extending from its roller and adapted to engage the loop of the belt of the other roller and in cooperation therewith to guide and control the roving being drawn, at least one additional endless belt within at least one of the first mentioned belts and passing round the roller thereof, said additional endless belt being adapted .to support and guide said iirst mentioned belt, and

means for drawing the roving from between the belts.

6. In a mechanism for drawing textile rovings, the combination of a pair oi' rollers, at least two endless belts, one within the other passing round each of the said rollers, each inner endless belt being adapted to support and guide its outer belt and each belt forming a loop extending from its roller, the outermost belt of one roller being adapted to engage the outermost belt of the other roller and in cooperation therewith to guide and control the roving being drawn, a pair of front rollers for drawing the roving from between the belts, and tensor means within the loop of each of the said outermost belts, said tensor means being so located relatively to the front rollers that the front nip of the said belts is closely adjacent the nip of said front rollers.

'1. In a mechanism for drawing textile rovings, the combination of a pair of rollers, an endless belt passing round each of said rollers, each belt forming a loop extending from its roller and adapted to engage the loop of the belt of the other roller and in cooperation therewith to guide and control the roving being drawn, tensor means within each of said loops, at least'one additional endless belt within at least one of the first mentioned belts and passing round the roller thereof, said additional endless belt being adapted to support and guide said first mentioned belt, means engaging at least one inner belt to modify the pressure of its outer belt on the roving, and means for drawing the roving from the belts.

8. In a mechanism for drawing textile rovings, the combination of a pair of rollers, an endless belt passing round each of said rollers, each belt forming a loop extending from its roller and adapted to engage the loop of the belt of the other roller and in cooperation therewith to guide and control the roving being drawn, tensor means within each oi said loops, a plurality of additional endless belts within each of the iirst mentioned belts and passing round the rollers thereof, said additional endless belts being adapted to support and guide said iirst mentioned belts, a plurality of members, one cooperating with each o! the said additional inner belts to modify the pressure of said first mentioned outer belts on the roving, and means for drawing the roving from between the belts.

9. In a mechanism .for drawing textile rovings, the combination of a pair oi.' rollers, an endless belt passing round each of the said rollers, each belt forming a loop extending from its roller and adapted to engage the loop of the belt of the other roller and in cooperation therewith to guide and control the roving being dra at least one additional endless belt within and passing round the roller of each said ilrst mentioned belts. said additional endless belts being adapted to support and guide said first mentioned belts, stationary plates mounted outside and in contact with the outer belts to press same towards the path of the roving, and means for drawing the roving from between the belts.

FERNANDO CASABLANCAS.