US3001241A - Drafting train on continuous spinning machines - Google Patents

Description

Sept. 26, 1961 J. COMERMA AYMERICH 3,001,241

- DRAFTING TRAIN ON CONTINUOUS SPINNING MACHINES Filed May 2. 1958 Fig. 1

Zzz (1 6121501 all United States arena one Patented Sept. 26, 1961 3 001 241 DRAFTING TRAIN Oil (IONTINUGUS SPINNING MACHINES The present invention relates to a drafting train on continuous spinning machines of the type comprising two flexible aprons which retain the textile roving between them and accompany it to a point near the point of contact of the drafting rollers.

It is the main object of the invention to permit the application of the above-mentioned type of drafting train on continuous spinning machines to the rovings obtained by carding from waste or rte-manufactured textile fibres such as cotton, viscose fibres, wool, etc. Hitherto, it has not been possible, in the spinning of waste or re-rnanufactured material on continuous spinning machines equipped with a drafting rotor or with devices producing false twist, to obtain drafts better than With the improvements according to the present invention, drafts are obtained of between and and it is furthermore made possible to construct continuous spinning machines wherein there operate in tandem a drafting train of flexible aprons and a train having a drafting rotor or a false twist device, so that, in addition to the 40 to 60% draft effected by the first train, the draft effected by the second train is also obtained.

Another object of the invention is to provide a drafting train on a continuous spinning machine having two flexible aprons retaining and accompanying the textile roving between them to a point near the point of contact of the drafting rollers, wherein one of the aprons in its path in which it accompanies the roving forms a reentrant angle due to the forward guide member of the second apron, and said first apron has its forward end substantially nearer to the opposite drafting roller than the second apron, in such a manner that, before leaving the first apron, the roving surrounds the said first apron, in its forward part, over a path describing a convex pronounced arch, the roving departing from the apron at a point positioned nearer to the opposite drafting roller than to the other drafting roller and travelling over an arch-shaped path supported on the said opposite drafting roller.

Due to this manner of positioning the aprons of the drafting train, the result is achieved that one of the aprons ends at a point very near to the drafting rollers and that the path over which the roving travels without being accompanied by an apron is reduced to a considerable degree. In this manner, despite the fact that the roving contains a considerable proportion of short fibres, the number of fioating fibres is at a minimum, so that it becomes possible to subject the roving to a greater degree of drafting than would be possible if the said path over which the roving travels without accompaniment were to be longer.

In order to facilitate the understanding of the ideas underlying the invention and simultaneously to provide a practical example of the manner in which the invention may be realised, reference will be made below to the sheet of drawings accompanying this specification, which should be considered as being non-limitative vw'th regard to the scope of the invention. In the drawings:

FIGURE 1 is a front view of a drafting train according to the invention;

FIGURE 2 is a view in cross-section along the line 11-11 of FIGURE 1;

FIGURE, 3 is a, partial view, in an enlarged scale, of

preceding figure, showing the drafting rollers and the portion of the aprons nearest the said rollers.

In the various drawings, reference numeral 1 designates the textile roving which is being spun, reference numerals 2 and 3 represent the aprons retaining and accompanying the said roving, 4 and 5 designate the two drafting rollers, P is the point of contact of the said rollers 4 and 5, 6 and 7 are the forward guide members-revolving rollers in this examplerespectively guiding .the aprons Zand 3, and 8 and 9 are the rearward guide members for the aprons which, in this example, consist of a number of rollers having furthermore the function of feed rollers.

As will be seen in FIGURES 2 and 3, the apron 2 moves superposed on the apron 3 over the whole of the path section extending between the radius 8' of the roller '8 and the radius 7 of the roller 7. The pathover which the roving 1 is accompanied by the apron 2 extends from the said radius 8 to the radius 6 of the forward guide member 6 and consists of two parts, the said section of the path 8'7" over which the roving is doubly accompanied, due to the superpositioning of the two aprons, and the section of the path 7"-6 where the roving is accompanied by only a single apron. According to the invention, the forward guide member 6 forwardly guiding the apron 2 is nearer to the point of contact P than the for- Ward guide member 7 forwardly guiding the apron 3, the position of the said forward guide member 6 being such that the roving 1, before reaching the said point P, travels over a path bearing on the drafting roller 5; this path is the path lying between the radii 5 and 5" of the drafting roller 5. The difference in the distance of the forward guide members 6 and 7 from the point 1? makes it possible to move the forward guide member 6 to a point very near the said point P and the drafting roller 5, without the forward guide member 7 hindering it. In this manner, the path over which the roving travels after leaving the apron 2 at 6" and before reaching the point P, at which it is received by the two drafting rollers 4 and 5, may be made extremely short, and the path over which the fibres travel without being accompanied from the radius 6" as far as the radius 5 is still shorter. (In the drawings, the separating distance has been shown greater than is necessary, for the sake of greater clarity.)

According to the invention it is further proposed that the apron 2 shall, in its path wherein it accompanies the roving 1i.e. in the path extending from the radius 8' to the radius 6form a re-entrant angle due to the projecting position of the roller 7 which forwardly guides the apron 3. This re-entrant angle is designated A and the two sides of the said angle are the two portions ofthe apron 2 extending from 8 to 7 and from 7 to 6. In the example illustrated, it will moreover be seen that the relative position of the two aprons 2 and 3 is such that, due to the projecting position of the cylinder 8 acting as a rearward guide member of the apron 2, a second reentering angle B is produced in the apron 34.

With the aid of the re-entrant angles A and B there is obtained the mutual adaptation of the aprons, due to the fact that they partially surround each other. This adaptation has the advantage of improving the retaining and accompanying effect exerted by the aprons on the fibres and it helps to increase the drafting effect to an extent greater than that conventionally achieved. It should, however, be stated that, although there are two reentrant angles in the example illustrate-d, i.e. one reentrant angle for each apron, this does not prevent the provision, in other variants of embodiment of the invention, of two re-entrant angles on one and the same apron or of only one re-entrant angle on one of the aprons.

The guide members for the aprons 2 and 3, i.'e. the forward rollers 6 and 7 and the rearward rollers 8 and 9 are mounted in lateral support means, such as indicated by reference numeral 10 in FIGURES 1 and 2, the said support means being mounted in articulated form on a pivot 11 parallel to the rollers of the drafting train. In this manner, by rotation about the said pivot 11, the distance between .the point of contact P of the drafting roll- 'ers 4 and 5 and the forward guide member 6, which in this example is the one nearest the said point of contact P, may be adjusted at will. This measure provides a simple means of giving to the said distance a value proportional to the average length of the component fibres ofthe roving 1 which is being spun.

Having described the ideas underlying this patent of invention, it should be pointed out that the said inventionmay be put into effect with all those variants which practice may show to be advantageous in respect of dimensions, number of elements, materials used in construction, mode of interengagement and further accessory features, provided that the spirit of the invention is not contravened thereby and provided that the essential aprons, rearward and forward rollers for each apron with the aprons passing about the rollers, the rollers being so arranged that run sections of the aprons are adjacent each other between the rearward roller of one apron and the forward roller of the other apron, the forward roller of said other apron coacting with said one apron to provide a re-entrant angle, the forward roller of said one apron being substantially closer to one of said drafting rollers than the forward roller of said other apron so that the textile roving prior to leaving said one apron travels applied against said one apron at its forward roller over a path defining a pronounced convex arch and with the textile roving leaving said one apron at a point closer to said one drafting roller than to the other drafting roller so that the roving prior to reaching the point of contact of the drafting rollers travels along an arch-shaped path on said one drafting roller.

2. A drafting train as claimed in clainr 1 further including support means in which said rearward and forward rollers for said aprons are mounted, and means pivotally mounting said support means for movement about an axis parallel to said drafting rollers whereby the length of the path over which the textile roving travels may be adjusted.

References Cited in the file of this patent UNITED STATES PATENTS 2,675,585 Naegeli Apr. 20, 1954 2,695,428 Naegeli Nov. 30, 1954 2,926,393 Gardella Mar. 1, 1960 FOREIGN PATENTS 16,297 Great Britain of 1898 359,837 Great Britain Oct. 29, 1931

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