Technical Field

The subject invention concerns a package holder, for instance in an installation arranged for the production of the warp and according to which a tube with yarn wound thereon is slid axially onto the package holder, where it is retained in position while the yarn is being unwound from the tube.

Background of the Invention

Warp designates the array of lengthwise extending yarns on a loom that form the base of most textile materials. The production of a warp usually is carried out by unwinding yarns from a plurality of packages and assembling the individual yarns to form the warp. In other words, each yarn is unwound from its individual package. The yarn on the tubes is wound onto a tube having a central hole. The package is applied on a package holder which extends axially into the tube centre hole, and when the yarn on the tube is exhausted, the empty tube is removed from the holder. It is important that application and removal of the package is effected in a simple and quick manner. In one traditional installation for the production of warp, each yarn is carried from an eyelet into the warp. The yarn is supplied to the eyelet from a package from which it is unwound. The package is applied on a holder, the latter usually being an approximately horizontal rod onto which the package thus is pushed axially. Each eyelet has two yarn holders which are directed towards the eyelet in a manner ensuring convenient unwinding of the yarn. Packages are positioned on both holders and the .trailing end of the yarn on the first package is joined to the head end of the yarn on the second package. In this manner, automatic transfer occurs to the second package, and the empty tube of the first package may be removed from its

associated holder.

Since the internal diameter of the packages varies in size depending on the diameter of the tube on which the yarn is wound, it is desirable that the holders are equally effective for all sizes of the tube centre holes. In practice, this is achieved in that the holders are given an external diameter which is slightly smaller than the smallest tube that is useable in a particular appli¬ cation. This means that when packages having a large internal opening, i.e. large centre-hole tubes, are used, considerable play exists between the holder and the tube. When most of the yarn on the package has been unwound and consequently the package is light, problems of vibration may occur, i.e. the package starts to move on the holder during the unwinding procedure. Since tubes having differently sized centre holes are used, the centres of the tubes, and consequently the centre of the entire package, will be positioned at different heights in relation to the holder. However, it is not desirable to have to adjust the vertical position of the holder in relation to that of the eyelet upon tube exchanges, and therefore one has adopted the method of instead adapting the holder setting to a suitable average tube size. This means that when a tube having a larger-than-average centre hole is used, the package will assume a lower position than intended with respect to the eyelet. As a result, unwinding of the yarn in the vertical direction on the lower side of the tube will be more difficult than on the upper tube side with consequential uneveness of unwinding. In order to solve the above problem special tube centering devices have been developped. According to one common method the package holder is provided with a replaceable core which may be exchanged for another, suitably sized core as one changes to a package having a different tube from that of the previous one. However, this method requires that a large number of cores must be kept in stock, and also extra work for core exchanges.

In accordance with another solution, centering devices operating on pressurized air are used. However, in this case access to sources of pressurized air is of course required as well as extensive piping in the frame part for the supply of pressurized air to each individual holder.

Purpose of the Invention

The purpose of the subject invention is to create a package holder of simple construction which is designed to considerably lessen the problems outlined in the afore¬ going. Owing to the simple construction, no access to pressurized air or other similar operative media is require .

Summary of the Invention

The above purpose is achieved by providing the package holder in accordance with the invention with the characteristics appearing from the appended claims. The package holder in accordance with the invention thus is characterized essentially therein that it is composed of a base member having support areas on which the package is gravity-supported by means of the upper part of its internal opening, said base member being provided with means for sensing the diameter size of said internal package opening as also with means arranged, in dependence of the diameter size of the internal opening, to actuate said package support areas to a corresponding degree in order to tip the package vertically to achieve even unwinding. In other words, when a tube having a large centre opening is used, the package is tilted in a vertical direction in a manner ensuring that the package centre is directed essentially towards the eyelet, whereby even unwinding is achieved. Owing to the invention, automatic alignment of the package on the holder thus is achieved, whereby the package will be directed towards the eyelet. The requirement is that the tube positioned inside

the package has an internal diameter within the operative range of the holder. In addition, the means used to detect the internal diameter and to affect the support areas will exert a certain clamping effect radially on the package, obviating the problem connected with vibrations.

In accordance with one particularly simple and efficient embodiment of the invention the sensing of the internal diameter of the package is effected by means of a pivotable flap. A biased spring acutates the flap for pivotal movement outwards transversely from the base member of the package. When a package which is suitable for the holder is applied on the holder the lower part of the flap will move into contact with the lower part of the internal opening of the package and thus sense the internal diameter size of the package opening. The flap is mounted in the base member of the holder at a point remote from its lower part. On the side opposite the mounting shaft the flap is formed with an upper part which, upon pivotal movement of the flap, will project progressively above the upper face of the base member. This pivotal movement outwards will bring the outer end of the package, i.e. the end closest to the eyelet, to be lifted by the upper side of the flap. In a very simple yet reliable manner the corrective means are created that are required to accommodate tubes of different internal diameter sizes. The opposite end of the package abuts against the inner end of the holder, i.e. against the end remote from the eyelet. The spring-biased flap thus will serve to sense the internal diameter of the tube and consequently to a varying degree affect one of the support areas of the package to ensure adequate tilting-up of the package at the outer edge thereof.

Brief Description of the Drawings

The invention will be described in closer detail in the following by way of one embodiment thereof with reference to the accompanying drawings, wherein identical numeral references have been used in the various drawing figures to indicate identical parts, and wherein:

Fig. 1 is a perspective view of one section of an installation for producing the warp.

Fig. 2 is a cross-sectional view of the holder as seen from the side.

Fig. 3 is a view from above of the holder of Fig. 2. Fig. 4 shows the holder of Fig. 2 as seen from the free end thereof.

Fig. 5 is a lateral and partly cut view showing the cooperation of the holder with a package having a compara¬ tively large internal opening.

Fig. 6 is a lateral and partly cut view showing the manner of cooperation of the holder with a package having a comparatively small internal opening, and Fig. 7 is a lateral and partly cut view showing the manner of cooperation of the holder with a heavy-weight package.

Detailed Description of Preferred Embodiments In Fig. 1, numeral 1 designates a package holder in an installation for setting up a warp 2. The warp 2 consists of an array of parallel yarns which are assembled in a yarn assembling device 6. Via an eyelet 5, each yarn 4 is supplied from a package 3 onto which the yarn has been wound. The yarn 4 is unwound from the package 3. The yarn 4 is wound about a tube and the inner end of the yarn 4' projects somewhat externally of the tube. In this manner it becomes possible to join together the yarn of a fresh package with yarn 4' and to place the fresh tube on the adjacent holder 1. When the yarn on the first package is exhausted automatic transfer will take place over to the new package. In Fig. 1 is illustrated precisely this

situation with respect to the second eyelet according to which two packages are in position on adjacent frame parts and they are interconnected by means of a joined-together yarn extending between them. As appears from Fig. 1, the empty holder 1 is directed towards the eyelet 5. In an identical manner the foremost holder supporting a package 3 is directed towards the same eyelet 5. Each pair of holders 1 thus is directed to its respective eyelet 5. For easy package changes it is important that a fresh package may be applied on the holder and that an empty tube may be conveniently removed from the holder.

Figs. 2 to 4 inclusive illustrate the construction of the holder in accordance with the invention. It essential¬ ly comprises a base member 7 over which the package is applied in such a manner that its tube is supported on the base member. In accordance with the embodiment illus¬ trated, one end 13 of the base member 7 is provided with a threaded pin by means of which it is to be secured to the frame part of the installation. At its opposite end 12, i.e. the outer one in relation to the frame part, the base member 7 is provided with a flap 9. The flap 9 is mounted for pivotal movement about an articulation shaft 14. The flap is actuated by a tension spring 10 which is arranged to hold the flap in an outwards directed angular position which is restricted by a stop member 15. In other words, the tension spring is biased in this position. Over the majority of its length the flap 9 has a U-shaped cross- sectional configuration including two parallel side walls 20, 21 with the open side of the U-shape facing the spring, whereby the spring may be accommodated inside the flap in the inner position of the flap. The flap 9, in its turn, then may be housed in the interior of the base member 7. This is possible because the base member essentially comprises two parallel side walls 16 which are interconnected by an end wall 18 facing the frame part, and the stop member 15. The flap 9 may be pivoted upwards between the two parallel side walls 16, 17. By means of

one of its ends, the spring 10 is attached to a hinge-pin 19 extending between the parallel side walls 20, 21 of the flap 9. The opposite end of the spring 10 is attached to a bolt 22 extending between the parallel side walls 16, _. 17 of the base member 7. The attachment loops of the spring thus may turn about the hinge pin and the bolt, respectively.

The flap 9 is oblong and comprises an end portion 23 which is intended to cooperate with the lower part of the internal opening 8 in the package 3. Its opposite end portion 24 is intended to cooperate with the upper part of the internal opening 8 of the package 3. The articulation shaft 14 about which the flap is arranged to pivot, is positioned intermediate these end portions, comparatively close to the upper end portion 24 intended for cooperation with the upper part of the internal opening 8. The tension spring 10 is held between the articulation shaft 14 and the upper end portion 24 so as to pivot the flap outwards. Instead of a tension spring it would also be possible to use a pressure spring. However, the latter should be arranged to act on the opposite side of the articulation shaft 14 in order to pivot the flap outwards. Other types of spring elements could also be used, such as gas- operated springs or an air cylinder or hydraulically operated cylinder. The essentialy feature is that satisfactory spring characteristics for the flap movements are provided. The solution involving a tension spring provides easy attachment of the spring and at the same time little friction during the spring-activated movement. In addition, no access to sources of pressured air or hydraulic fluids is required.

Figs. 5 to 7 inclusive illustrate the manner of operation of the holder in conjunction with various types of packages. The purpose of the present invention is to provide correction for packages of different sizes by means of a simple and reliable holder. The way the holder functions for this purpose is clearly apparent from a

comparison between Figs. 5 and 6. The package 3 of Fig. 5 has a comparatively large internal opening 8. This means that the tube 25 onto which the yarn 4 is wound has a comparatively large internal diameter. As a result, the pivotal movement outwards of the flap 9 will be compara¬ tively large. In fact, it will be positioned almost in abutment against the stop member 15. Upon such pivotal movement outwards, the upper part 24 of the flap will abut against the upper part of the tube 25 and in doing so tilt the outer end of the tube upwards. At the inner end 13 of the holder, on the other hand, the tube 25 will remain in contact with the base member 7. In this manner the package will be tilted up in relation to the holder 1. As a result of this tilting up the unwinding angle Ψ _β at the the upper edge of the package will be equal to the reeling angle Ψ of the yarn 4 at the lower package edge. Owing to the geometry and the dimensions of the flap and to the choice of position of its articulation shaft 14, this correction may be made to function very well with tubes 25 of different sizes.

Fig. 6 illustrates the case when the tube 25 has a considerably smaller internal diameter. In this case, the flap 9 will be pivoted outwards by a small amount only and consequently, less tilting up of the package will occur. As a result, the unwinding angles Ψ„ and Ψ of the yarn 4 at the upper edge and the lower edge, respectively will again be equal. Assuming the border case, wherein the inner diameter of the tube 25 is equal to the largest transverse dimensions of the base member 7 in the holder, the flap 9 will be folded inwards to its innermost position as the package is being applied and there will be no tilting up of the package position. However, also in this case correct unwinding angles are obtained, provided that the centre line of the holder is directed towards the eyelet 5, which is the position in which the holder is normally set.

In the above situations shown as examples, the agree¬ ment between the unwinding angle Ψ„ at the upper edge of the package and the unwinding angle Ψ at the lower edge thus will be satisfactory, resulting in even and well. functioning unwinding conditions.

Fig. 7 illustrates an entirely different situation. In this case, the package 3 is so heavy that the tension spring 10 is incapable of turning the flap 9, since this would have involved lifting the heavy package 3 at the outer end 12 of the holder 1. In this case, therefore, there is no tilting up of the package and thus not either any correction of the unwinding angles. Angle Ψ„ therefore will be larger than Ψ but it should at the same time be understood that in the case of such a heavy and large package 3 the unwinding speed is low and that consequently the unwinding conditions are less critical than in the case of a smaller package. In addition, the package 3 will become lighter when more yarn has been withdrawn, with the result that the spring force will suffice to effect the correction under the more critical unwinding conditions prevailing when the outer diameter of the package 3 is smaller.

It can thus be seen that in order to obtain overall satisfactory function with packages 3 supporting com- paratively moderate amounts of yarn, a spring of a certain spring force is required, a feature which has priority inasmuch as the unwinding conditions are most critical when the diameters of the package 3 are small. Satisfactory correction also in the case of large and heavy packages would have required a considerably more complex solution, taking into consideration also such aspects as the weight of the package and, in dependence thereof, adjustments of air or oil pressures. A solution of this nature would have been a great deal more expensive, and, owing to its complexity, would have increased the risks of faults. If a very rigid spring were to be used under all conditions, application and removal

respectively of packages and tubes would have been made more difficult and the maximum folding-outwards of the flap would have had to be somewhat restricted in order to avoid interference with the tube removal. The configuration of the surfaces of the flap 9 that come into contact with the tube 25 is of utmost importance if the holder is to function satisfactorily. Normally, the lower end 23 as well as the upper end 24 of the flap therefore are well rounded and present a smooth configura- tion in order to reduce friction. In addition, these end portions could be surface-coated in order to reduce friction and wear. When the empty package 25 is to be removed from the holder 1, the frictional force will tend to pivot the lower flap end 23 outwards. The risk is that this locks or stops the unwinding movement. This aspects determines the upper limit of the size of the internal diameters of the tubes 25 before such locking occurs. The reason is, that the risk of blocking increases the more the flap is folded outwards. The ends of the flap should have a well rounded configuration. The material of the flap and that of the base member could be metal or plastics. When the friction at the flap ends is low, particularly at the lower end 23, a comparatively large maximum pivotal movement of the flap is conceivable, and the operative range of the flap will be increased correspondingly.