This invention relates to the preparation of fibres for spinning.

In the preparation of fibres for spinning it is necessary to straighten and align the fibres to a certain extent. In the production of woollen yarn it is conventional to card the fibres to disentangle them. This produces a thin web of fibres which is split into strips. The strips are fed to rubbing aprons which consolidate the strips into slubbings. The consolidation process is slower than the carding one and is a bottleneck in the process. A large investment in rubbing aprons is needed to maximise the use of a card. The slubbings are often too thick for a required yarn fibre count so they have to be divided again, particularly for ring spinning which is a preferred system for spinning the longer fibres of woollen yarns.

US-A-3 358 432 proposes a technique for spinning yarn from sliver with a ring spinner in which drafting problems are reduced by supporting fibre being drafted on card-clothing covered rollers.

It is an object of the invention to improve the process of spinning yarns, particularly long fibre woollen yarns, by removing or reducing the need for rubbing aprons in the preparation of the fibres for the spinning stage.

According to the invention there is provided a fibre preparation apparatus including means to receive sliver from a card, means to both open the sliver in to fibres and direct the fibres on to a moving elongate surface, means to exert suction to collect the opened fibres on said elongate surface, control means urged against the surface to hold collected fibres to the surface, means to withdraw collected fibres from between the control means and the surface as a continuous strand and supply the strand to a ring spinning arrangement.

The means to withdraw collected fibres may include means to draft the strand to a required count. The means to withdraw collected fibres may include means to apply a false twist to the strand.

Suction may be applied to hold the collected fibres on the surface. The surface may be the peripheral curved surface of a hollow disc. The surface may have a groove to receive the fibres.

According to the invention there is also provided a method of preparing a sliver of fibres for spinning including:
   opening fibres from the sliver on to a surface,
   collecting opened fibres on said surface by suction,
   moving collected fibres on the surface past a control means urged against the surface,
   withdrawing collected fibres from between the surface and the control means as a continuous strand and supplying the strand to a ring spinning arrangement.

According to the invention there is further provided a method of preparing fibres for spinning including
   carding fibres to a state to be suitable for rubbing into slubbings,
   presenting the carded fibres as slivers,
   opening fibres from the sliver,
   directing fibres by said opening action on to a collecting surface,
   holding fibres on the collecting surface,
   moving collected fibres held on the surface past a control means urged against the surface,
   withdrawing collected fibres from between the surface and the control means as a continuous strand and supplying the strand to a spinning arrangement.

The method may include the introduction of a core yarn and wrap spinning the fibres onto the core yarn.

Embodiments of the invention will now be described with reference to the accompanying drawing which shows in schematic form a fibre preparation apparatus according to an aspect of the invention.

In the drawing a generally conventional opening wheel is indicated at OW. A collecting device CD is conveniently of hollow disc form with the peripheral curved collecting surface CS perforated to permit suction to be exerted through the surface by means not shown but indicated by arrow SU. Over part of the periphery suction is obstructed by a suitable plate or like device OB inside the disc. The disc is arranged to rotate in the direction indicated. The opening wheel OW is arranged to direct fibres F opened from a sliver S from a supply SC, in conventional manner, onto the collecting surface CS. The opening wheel rotates past the surface CS in the direction shown by the arrow. Other relative rotations are possible. A control means, such as a rubber control roller CR, is urged against the collecting surface e.g. by spring SP, to provide a "nip" and revolves with the rotation of the disc CD. Over the greater part of the surface CS, between opening wheel OW and control roller CR, the collected fibres are held by the suction SU. Suction is obstructed elsewhere, as mentioned above.

In operation of the apparatus, as described so far, the individual fibres F opened from the sliver S by the opening wheel OW are moved directly onto the collecting surface CS, partly by the action of the wheel and partly by the suction through the perforated surface. The fibres can be held to the surface by the suction as the disc rotates although in any cases suction only at the initial approach to the surface is enough to ensure that the fibres stay in place on the disc surface. The pressure produced by suction can of course be produced in other ways if preferred, as stated below, the present embodiment being only an example. The opened fibres are not allowed to "float" or form a cloud, being under control throughout the movement between the opening device and the collecting surface. On the surface the fibres have the general appearance of the fibres in a card web. As the disc CD rotates the fibres are carried into the "nip" between the control roller CR and the disc.

From the "nip" the fibres, which now are a loosely-formed fibre strand FS, are drawn through a pair of parallel friction-twisting belts TB and a pair of drafting rollers DR. The belts apply a false twist and the rollers draft, i.e. draw out, the strand to a required count. The strand is then supplied to a conventional ring-spinning arrangement RS. The false twisting operation can be omitted. The drafting operation can be omitted. The degree of false-twisting and/or drafting, if any, is adjusted as required. Preferably the strand prepared as described produces the same surface structure in the spun yarn as does the slubbing which has been treated by the rubbing aprons of the conventional technique. When long fibres are used, for which condenser technique is appropriate in the present art, the yarn surface structure preferably emulates that of condenser produced yarn.

Typically the opening wheel is about 100 millimetres in diameter. The collecting device disc is conveniently about 160 millimetres in diameter with a curved surface about 30 millimetres wide. The perforated area is about 10 to 20 millimetres wide along the middle of the surface. Lips are provided at each side of the surface and the "nip" control roller fits between the lips to hold the fibres against the surface. The surface may be flat or shaped but the control roller must be shaped to fit. The surface can have a V-groove about 10 millimetres wide, provided with perforations, to receive the fibres. The control roller is arranged to exert a "nip" similar to that in conventional processes.

As distinct from the conventional preparation of wool fibres for ring spinning, which requires extensive carding, splitting of the web and slubbing using rubbing aprons before spinning a sliver produced by less-extensive carding and without the need for slubbing can be readily and economically prepared and supplied to a ring spinner using the apparatus embodying the invention.

The techniques described are particularly suitable for the longer fibres, about one hundred millimetres or more, of wool for which ring spinning is preferred but the techniques are suitable for shorter fibres. Wool fibres range from twenty to four hundred millimetres in length. A further gain in efficiency is possible as the capacity of a slubbing bobbin is generally much less than that of a sliver can, so when fed from slivers a ring frame can run with much less down-time. Also the transport of sliver In cans is simpler than that of slubbing bobbins.

The dimensions, speeds and pressures given by way of example are those for a typical arrangement embodying the invention and suitable ranges for these will be readily apparent to those skilled in the art, having regard to the nature and length of the fibres to be handled and the yarn required. For example a core yarn could be wrapped with the fibres by introducing the core yarn into the arrangement.