US3562869A - Textile fibre drafting mechanisms - Google Patents

Abstract

A FIBRE GUIDE IMMEDIATELY PRECEDES THE INTAKE OF A TEXTILE FIBRE DRAFTING MECHANISM AND PROVIDES A CONFINED PASSAGE THROUGH WHICH FIBRE IS FED TO SAID INTAKE AND FROM WHICH FIBRE IS PAID OUT UNDER TENSION, THE GUIDE HAVING FIBRE GUIDE SURFACES THAT MOVE ALONG WITH THE FIBRE CONFINED THEREBETWEEN.

Description

Feb. 16, 1971 J, NOGUERA 3,562,869

TEXTILE FIBRE DRAFTING MECHANISMS Filed Aug. 2, 1968 United States Patent Office 3,562,869 Patented Feb. 16, 1971 3,562,869 TEXTILE FIBRE DRAFTING MECHANISMS Joseph Noguera, London, England, assignor to Casablancas Limited, Manchester, England, a British com- Filed Aug. 2, 1968, Ser. No. 749,789 Claims priority, application Great Britain, Aug. 3, 1967, 35,671/ 67 Int. Cl. D01h 5/72 US. Cl. 19-288 11 Claims ABSTRACT OF THE DISCLOSURE A fibre guide immediately precedes the intake of a textile fibre drafting mechanism and provides a confined passage through which fibre is fed to said intake and from which fibre is paid out under tension, the guide having fibre guide surfaces that move along with the fibre confined therebetween.

This invention relates to textile fibre drafting mechanisms for preparatory or spinning machines and is concerned with facilitating the efficient guiding of textile fibres into the intake in such a mechanism.

As is well known, textile fibres delivered to drafting mechanisms of spinning or preparatory machines may be in the form of coiled sliver accommodated within a container, or in the form of twisted roving wound on to a bobbin. In either case, it is usual practice to provide some form of fork or funnel which is situated in front of a nip of a first pair of drafting rollers to which the sliver or roving is to be delivered and which serves to guide the sliver or roving into the aforesaid nip. Such forks or funnels, commonly known as sliver or roving guides, can be of various shapes and differ from one another mainly in their length and sectional area or aperture size.

In the majority of cases, a relatively long guide with an aperture having a relatively small cross-sectional area is preferred for optimum presentation of the fibres to the drafting mechanism. Unfortunately, however, there are severe limitations upon length and aperture size of the guide arising from various causes. Not least among these causes is that, as a guide acts more tightly upon the sliver or roving passing through it, there is an increased tendency to cause the leading ends of the outer fibres to fold backwards making so-called fibre hooks which is a very troublesome factor in drafting. In addition, the action of a tight guide upon a roving obstructs the free passage of the roving twist, with the result that extra twist accumulates behind the guide until it eventually passes through the guide. This means that, in such cases, there will be lengths of under-twisted roving fed into the drafting mechanism followed by lengths of over-twisted roving. All this is again disadvantageous from the point of view of efficient drafting because the drafting mechanism is alternately presented with a soft and then with an unyielding formation of fibres. Yet another disadvantage of tight guides is that the resistance to be overcome in pulling the fibres through the guide varies with the inevitable irregularities of the sliver or roving and, in consequence, there is a risk of stretching and thereby causing further irregularities.

As distinct from the guides which are too tight or act too strongly upon fibre strands passing therethrough, wider or looser guides have the serious disadvantage of not presenting the fibres to the following drafting mechanism in a sufficiently straightened and well oriented manner. Looser guides also have the disadvantage of not securing a uniform feed since, when the roving or silver happens to be somewhat taut and straight or well directed,

it will be fed into the following drafting mechanism at a slower rate than when it hapeens to be slack or on a bias.

A main object of the present invention is to obviate the various disadvantages and drawbacks of the known sliver or roving guides.

Accordingly, the invention provides a method of guiding textile fibres into the intake of a drafting mechanism wherein the fibres approaching said intake are confined by guide means which immediately precede said intake and from which the fibres are paid out to the intake under tension, said guide means being moved along with the confined fibres.

According to a further aspect, the invention provides a textile fibre drafting mechanism wherein a roving or sliver guide immediately preceding the intake of the mechanism has co-operating guide surfaces which provide therebetween a confined passage through which the sliver or roving is fed to said intake and from which the sliver or roving is paid out under tension, said guide surfaces being arranged to move along with the sliver or roving confined therebetween.

For a better understanding of the present invention and to show how the same may be carried into effect ref erence will now be made, by way of example, to the accompanying drawings, in which:

FIG. 1 is a diagrammatic side view of a first form of roving or sliver guide shown disposed for guiding roving or sliver to a pair of co-operating drafting rollers,

FIG. 2 is a plan view from above of the guide and drafting rollers shown in FIG. 1,

FIG. 3 is a side view, taken in the direction of arrow III of FIG. 1, of the guide of FIG. 1,

FIG. 4 is a diagrammatic plan view from above of a second form of roving or sliver guide shown disposed for guiding roving or sliver to a pair of co-operating drafting rollers,

FIG. 5 is a diagrammatic side view of the guide and drafting rollers shown in FIG. 4,

FIG. 6 is a diagrammatic plan view from above of a first modified form of the guide of FIGS. 4 and 5, and

FIG. 7 is a diagrammatic plan view from above of a second modified form of the guide of FIGS. 4 and 5.

The various forms of roving or sliver guide shown in the figure are for use with a conventional textile fibre roller drafting mechanism composed of a number of consecutive pairs of co-operating drafting rollers. Sliver or roving to be drafted is fed to the intake nip between the first pair of drafting rollers of the mechanism from a container or bobbin as the case may be, the sliver or roving being guided into the nip through a so-called sliver or roving guide. Each such guide shown in the figures is arranged to exert a preferably yielding confining action on the fibre strands forming the roving or sliver, approaching the intake roller nip and right up to a delivery point which closely precedes the nip. In this way, a maximum control can be exerted on the fibres passing through the guide and it is possible to ensure a very high degree of accuracy both in orientation and tautness of the fibres delivered to the nip. At the same time the guide surfaces which actually exert the confining action on the fibres are arranged to move with the fibres so that any twist which may be in the fibres entering the guide remains substantially unchanged when the fibres are paid out at the delivery point. Furthermore the leading fibre ends will have little or no tendency to form fibre hooks. In this way an extremely regular presentation of the fibres to the intake nip of the drafting mechanism can be achieved since the right degree of control can be applied while the risk of producing twist or other irregularities is minimised.

The first form of roving or sliver guide 1 shown in FIGS. 1 to 3 disposed for guiding roving or sliver to one pair of co-operating drafting rollers 2, 2 is formed by a pair of co-operating guide rollers 3, 3 rotatably mounted on upright pins 4, 4 carried by a support bracket 5. This bracket 5 is secured to the traverse rod 6 of a textile fibre drafting mechanism so that the axes of rotation of the guide rollers 3, 3 are at right-angles to the axes of rotation of the drafting rollers 2, 2, and the nip between the guide rollers 3, 3 immediately precedes the intake to the drafting mechanism constituted by the nip between the drafting rollers 2, 2. On the side of the nip between the guide rollers 3, 3 remote from the drafting rollers 2, 2 there is a further guide formed by a funnel 7 (not shown in FIG. 3) disposed for guiding roving or sliver into the nip between the guide rollers 3, 3. The funnel 7 is carried by a bracket 8 that is fast with the traverse rod 6. In modified forms, not shown, the guide rollers 3, 3 are supported for rotation about axes parallel with the axes of rotation of the drafting rollers 2, 2 or for rotation about axes inclined with respect to the axes of rotation of the drafting rollers 2, 2.

In use of the first form of guide, textile fibres formed as roving or sliver drawn into the drafting mechanism by the drafting rollers 2, 2 which are driven, pass to the rollers 2, 2 via the funnel 7 and the nip between the guide rollers 3, 3. The guide rollers 3, 3 are urged towards one another, preferably resiliently, by a mechanism, not shown, so that the nip therebetween forms a confined passage through which the fibres are fed, whereby the fibres experience a resistance to their movement through the nip between the guide rollers 3, 3 and hence are paid out from this nip under tension. The mechanism urging the guide rollers 3, 3 towards one another can be overridden so that these rollers can be moved apart to facilitate insertion of the roving or sliver at the commencement of operation. The passage of the roving or sliver between the guide rollers 3, 3 causes these rollers to rotate and hence the curved surfaces of these rollers form co-operating guide surfaces that move along with the fibres confined therebetween. A mechanism (not shown) may be provided for braking the rotational movement of the guide rollers 3, 3 so that the amount of resistance offered to the passage of the fibres can be selected. Furthermore the guiding surfaces of the rollers 3, 3 may be patterned in any desired way so as to facilitate positive engagement with the roving or sliver and minimize the risk of slipping.

It will be appreciated that the configuration of the funnel 7 is such as not to restrain the fibre strands to any substantial degree.

The second form of roving or sliver guide 1A shown in FIGS. 4 and 5 disposed for guiding roving or sliver 9 to one pair of co-operating drafting rollers 2, 2 includes a pair of co-operating elongated guide sulfaces constituted by co-operating runs of two flexible idler endless bands 10, 10 which are mounted so as to be capable of revolving around support blocks 11. These support blocks 11 for the bands 10 are themselves mounted in a stationary position and at a location such that the co-operating band runs extend parallel to the fibre feed path and over an appreciable length of the path up to a delivery point which closely precedes the nip between the pair of drafting rollers 2, 2. The length of the co-operating band runs will, of course, depend upon the size of the bands 10, 10 employed and the form of the support blocks 11, but are normally chosen so as to provide a confining path of appreciable length for the fibres.

Displacement of the co-operating band runs, and thus also rotation of the bands 10, 10 around their support blocks 11, is brought about by the action of the sliver or roving 9 which passes between the band runs and is itself progressively drawn into the nip between the pair of drafting rollers 2, 2, which are driven as already mentioned. This arrangement tends to ensure that just the right amount of sliver or roving 9 is paid out from the guide 1A. For best results, the two bands 10 must offer a substantial degree of resistance to turning so that the fibre strands will enter the nip of the drafting rollers 32 in a taut condition and consequently at as uniform a rate as is possible. The facing surfaces of the co-operating band runs may also be patterned in any desired way so as to ensure a positive engagement with the fibre strands thereby tending to eliminate the risk of slipping.

Different degrees of grip upon fibre strands passing between the co-operating band runs, and a frictional resistance to movement of the bands 10 themselves, can be obtained in various ways. Thus, for example, bands 10 of different thicknesses may be employed or the size and shape of the band support blocks 11 may be varied. In the first modified form of guide 1A shown in FIG. 6 resistance to band movement is regulated by supplying different shapes or sizes of additional support elements 12 that can be selectively mounted within the forward ends of the band loops. In the second modified form of guide 1A" shown in FIG. 7 resistance to band movement is regulated by providing a band support block 11A with an angularly adjustable member 13 which can be caused to exert varying pressures on the inside surface of the return run of the associated band 10. In yet another arrangement (not shown), instead of providing for frictional resistance to band turning between the bands and their support blocks, the blocks are mounted to revolve and are braked in any desired manner to provide the necessary retarding action on the fibre strands being drawn between the band runs. In a further arrangement, not shown, brake means is applied to the edges of the bands themselves.

With all the forms of guide employing band runs a wide fork guide or very loose round guide may be arranged to precede the intake end of the co-operating band runs, merely to coax the sliver or roving into the bands without constraining the fibre strands to any substantial degree.

Any of the forms of guide that have been described can be covered in any suitable way to prevent the ingress of fly or dust.

I claim:

1. A method of guiding sliver to the feed rolls of a drafting mechanism, said method comprising drawing the sliver from the outlet of a funnel by said feed rolls, interposing idler guiding surfaces between said funnel and said feed rolls, receiving the sliver at the idler guiding surfaces from the outlet of the funnel such that the sliver progressively passes from the funnel to the guiding surfaces and then to the feed rolls of the drafting mechanism, guiding the sliver with said guiding surfaces while applying prescribed resistance to the sliver by said guiding surfaces, moving the guiding surfaces under the drawing action of the sliver and discharging the sliver from said guiding surfaces through said feed rolls and directly into said drafting mechanism with substantially no travel between the guiding surfaces and the feed rolls.

2. Apparatus for guiding sliver to the feed rolls of a drafting mechanism, said apparatus comprising a guide member with an outlet for the supply of sliver to be fed to said drafting mechanism, guide means for receiving the sliver from said guide member and for guiding the sliver to said drafting mechanism, drawing means including said feed rolls for pulling the sliver through said guide means, said guide means being interposed between the outlet of said guide member and said drawing means, said guide means having opposed freely movable cooperating guide surfaces defining therebetween a confined passageway through which the sliver passes from the outlet of said guide member to the feed rolls of the drafting mechanism, and means supporting said guide surfaces for travel with and under the action of the sliver while the surfaces offer prescribed resistance to the travel of the sliver.

3. Apparatus as claimed in claim 2, wherein at least one of said surfaces is round and constituted by a roller.

4. Apparatus as claimed in claim 2, wherein at least one of said surfaces is fiat and constituted by a belt.

5. Apparatus as claimed in claim 2, wherein said means supporting said guide surfaces further comprises means for applying frictional resistance to said guide surfaces to oppose advancement thereof with the sliver.

6. Apparatus as claimed in claim 2, wherein said guide means comprises a pair of cooperating rollers defining a nip therebetween which constitutes said confined passageway, said cooperating guide surfaces being formed by the curved surfaces of said rollers; said rollers being supported for rotation by the action of the sliver drawn through said nip by said drawing means, so that said curved surfaces move along with the sliver confined therebetween, and resist movement of the sliver through said nip whereby the sliver is paid out from said nip under tension.

7. Apparatus as claimed in claim 2, wherein said guide means comprises a pair of belts having cooperating runs, said cooperating guide surfaces being formed by the adjacent surfaces of said cooperating runs, said runs extending along the path along which said sliver is fed to said feed rolls to form said confined passageway, said belts being supported for movement along said path by the action of the sliver drawn therebetween by said drawing means, so that said runs move along with the sliver confined therebetween, and resist movement of the sliver whereby the sliver is paid out from between said runs under tension.

8. Apparatus as claimed in claim 7 comprising means 6 for applying braking movement to said runs along said feed path.

9. Apparatus as claimed in claim 7, wherein said means supporting said guide surfaces comprises a plurality of support elements differing in shape and size from one another about which each of said belts is passed.

10. Apparatus as claimed in claim 7, wherein said means supporting said guide surfaces comprises a member associated with each belt and around which each belt is passed, which member is adjustable in extent to effect variable braking of the movement of the belt.

11. Apparatus as claimed in. claim 2, wherein said guide member is a funnel urging the sliver to enter between said cooperating guide surfaces without itself constraining the sliver to any substantial degree.

References Cited UNITED STATES PATENTS 2,025,394 12/ 1935 Langen 19288X 3,067,471 12/1962 Noda 19243 3,417,436 12/1968 Masurel 19258 2,328,899 9/ 1943 Goodspeed 19-2'86 2,624,074 1/1953 Watson 19-286 3,020,697 2/ 1962 Henry 19-288 DORSEY NEWTON, Primary Examiner

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