Yarn storage device for a yarn processing machine

Abstract

The present invention relates to a yarn storage device for a yarn processing machine, a method for supplementing a yarn store in said yarn storage device and a yarn processing machine provided with said yarn storage device, wherein the yarn storage device comprises storage units (2, 7) and loading means (3) in order to add yarn in a selected storage unit, wherein at least one storage unit comprises a winding holder (7) that is provided to keep a yarn store in a state wound round a holder body (7c), and wherein preferably yarn is added in windings with a winding diameter (D.sub.1) that is greater than the radial dimensions (D.sub.3) of the holder body (7c).

Claims

1. Yarn storage device for a yarn processing machine comprising at least two storage units that are provided in order to hold a respective yarn store for the yarn processing machine, and at least one loader that is provided in order to join an end of the yarn of a selected storage unit to an end of an external amount of yarn and to add yarn from the external amount of yarn to the yarn of the selected storage unit, wherein at least one storage unit comprises a winding holder with a holder body that is provided in order to keep the windings of a yarn store in a state wound round this holder body, wherein the loader is provided in order to add yarn from the external amount of yarn to the yarn of the selected storage unit in windings with a winding diameter that is greater than the radial dimensions of the holder body, such that the windings are held as successive windings placed one after another in the state wound round the holder body.

2. Yarn storage device for a yarn processing machine according to claim 1, wherein the holder body of at least one winding holder defines a holder surface for the windings, and in that the respective storage unit comprises at least one guider to lead the yarn away from the yarn store of the yarn storage unit during unwinding thereof from the holder surface.

3. Yarn storage device for a yarn processing machine according to claim 2, wherein the at least one guider is provided in order to unwind the yarn from the holder body with an unwinding diameter that is greater than the radial dimensions of the holder body.

4. Yarn storage device for a yarn processing machine according to claim 3, wherein the at least one guider comprises an unwinding head connected to the holder body, whose radial dimensions are greater than the radial dimensions of the holder body.

5. Yarn storage device for a yarn processing machine according to claim 3, wherein the at least one winding holder comprises a transition part with a first end abutted to the holder body whose radial dimensions are almost the same as the radial dimensions of the holder body, and a second end directed towards the at least one guider whose radial dimensions are almost the same as the unwinding diameter and in that the radial dimensions of the transition part gradually increase from the first end to the second end.

6. Yarn storage device for a yarn processing machine according to claim 5, wherein, seen in a vertical cross-section of the holder body, a first line that extends in the extension of the upper side of the transition part and a second line that extends in the extension of the upper side of the holder body enclose an angle that is not greater than 60°.

7. Yarn storage device for a yarn processing machine according to claim 1, wherein at least one storage unit comprises at least one guider that is provided in order to unwind the yarn from the holder body with an unwinding diameter that is greater than the radial dimensions of the holder body, and in that the ratio of the unwinding diameter to the winding diameter is between 0.99 and 2, inclusive.

8. Yarn storage device for a yarn processing machine according to claim 1, wherein at least one winding holder comprises a winding-up part connected to the holder body, in that the at least one loader is provided in order to add yarn from the external amount of yarn to the yarn of the selected storage unit by winding it onto the winding-up part of the respective winding holder, wherein the windings on the winding-up part are gradually moved towards the holder body, and in that the winding-up part has radial dimensions that are greater than the radial dimensions of the holder body.

9. Yarn storage device for a yarn processing machine according to claim 8, wherein the at least one winding holder is incorporated in a yarn storage space with a supply opening, and is movable between a position of rest wherein the winding-up part is largely located within the yarn storage space of the storage unit and a winding-up position wherein the winding holder extends via the supply opening to outside the yarn storage space and wherein the winding-up part is largely located outside the yarn storage space, and in that the yarn storage device is provided in order to bring the winding holder from a selected storage unit into the winding-up position.

10. Yarn storage device for a yarn processing machine according to claim 9, wherein at least one storage unit comprises at least one guider that is provided in order to unwind the yarn from the holder body, and comprises the winding holder that is incorporated in the yarn storage space with a discharge opening via which the yarn is displaced towards the yarn processing machine, and in that the winding holder extends in the position of rest via the discharge opening to outside the yarn storage space so that the at least one guider is located at least partially outside the yarn storage space.

11. Yarn storage device for a yarn processing machine according to claim 1, wherein at least one storage unit comprises one or more flexible and/or deformable and/or movable supporting elements that support the winding holder, and in that each supporting element is positioned so that at least some supporting elements come in contact with the yarn during unwinding of the yarn, and in that the supporting elements are bent and/or deformed and/or moved by the forces that the yarn exerts directly or indirectly thereon, and thereby allow the yarn to pass through.

12. Yarn storage device for a yarn processing machine according to claim 1, wherein at least one storage unit comprises one or more forcers that are provided in order to exert a contactless force on the winding holder, so that the winding holder is forced by this contactless force to a predetermined operating position.

13. Yarn storage device for a yarn processing machine according to claim 1, wherein at least one storage unit comprises at least one guider in order to lead the yarn away from the yarn store during unwinding thereof from the holder surface, and in that the winding holder and the at least one guider is supported by a common rotatable shaft.

14. Yarn processing machine provided with at least one yarn storage device which comprises at least two storage units that are provided in order to comprise a respective yarn store for the yarn processing machine, and the at least one loader is provided in order to join an end of the yarn from a selected storage unit to an end of an external amount of yarn and to add yarn from the external amount of yarn to the yarn from the selected storage unit, wherein each yarn storage device is a yarn storage device according to claim 1.

15. Yarn processing machine according to claim 14, wherein it is a weaving machine, a tufting machine, a knitting machine or a beaming machine.

16. Method for replenishing a yarn store for a yarn processing machine wherein at least two storage units are provided that comprise a respective yarn store for the yarn processing machine, and wherein a selected yarn store is supplemented by joining an end of said selected yarn store to an end of an external amount of yarn and to add yarn from the external yarn store to the selected yarn store, wherein in at least one storage unit, a winding holder with a holder body is provided, and in that a yarn store is held in a state wound round the holder body, and wherein yarn is added from the external amount of yarn to the yarn of the selected storage unit in windings with a winding diameter that is greater than the radial dimensions of the holder body, such that the windings are held as successive windings placed one after another in the state wound round the holder body.

17. Method for replenishing a yarn store for a yarn processing machine according to claim 16, wherein the holder body of the winding holder defines a winding surface for the windings, and in that the yarn from each yarn store is led away from the winding surface during unwinding thereof.

18. Method for replenishing a yarn store for a yarn processing machine according to claim 16, wherein at least one winding holder comprises a winding-up part connected to the holder body, with radial dimensions that are greater than the radial dimensions of the holder body, and in that the external amount of yarn is added to the yarn of a selected storage unit by winding it onto the winding-up part of the respective winding holder and wherein the windings are then moved to the holder body.

19. Method for replenishing a yarn store for a yarn processing machine according to claim 16, wherein at least one winding holder defines a holder surface for the windings and in that the respective storage unit comprises at least one guider for unwinding the yarn from the yarn store of the respective yarn storage unit with an unwinding diameter that is greater than the radial dimensions of the holder body, so that the yarn is led away from the holder surface during unwinding thereof.

20. Method for replenishing a yarn store for a yarn processing machine according to claim 16, wherein at least one storage unit comprises the winding holder that comprises an unwinding head connected to the holder body, wherein the unwinding head has radial dimensions that are greater than the radial dimensions of the holder body.

Description

(1) In this detailed description, reference numbers are used for referring to the appended figures, where

(2) FIG. 1 is a perspective view of a yarn storage device according to the invention,

(3) FIG. 2 shows a side view of a winding holder of the yarn storage device according to the invention,

(4) FIG. 3 is an enlarged view of the winding holder in FIG. 2,

(5) FIG. 4 shows in perspective the rear of a number of yarn storage tubes of a yarn storage device according to the invention, with a winding holder in the position of rest and another winding holder in the winding-up position,

(6) FIG. 5 shows in perspective the front of the same yarn storage tubes as in FIG. 4, wherein the other ends of the same winding holders are also shown.

(7) FIG. 6 shows a vertical cross-section of the front part of a winding holder supported by a brush element,

(8) FIGS. 7a and 7b show a vertical cross-section of the front part of a magnetically supported winding holder, in the position of rest and in the winding-up position, respectively,

(9) FIG. 7c shows a cross-section according to axis B-B of the winding holder in FIG. 7a,

(10) FIG. 8 shows a vertical cross-section of the front part of a winding holder and an associated yarn guide tube mounted on bearings,

(11) FIG. 9a shows a vertical cross-section of the front part of another embodiment of a winding holder with a rotatable and axially slidable disk with a yarn feed-through eye, and

(12) FIG. 9b shows a cross-section according to axis A-A of the winding holder in FIG. 9a.

(13) The yarn storage device illustrated in FIG. 1 is used for supplying various yarns to a yarn processing machine, for example such as a weaving machine. This device is especially suitable for storing different yarns with unequal consumption in the yarn processing unit. The yarns provided in the yarn storage device are for example the pile yarns for a weaving machine for weaving pile fabrics.

(14) For each different type or colour of yarn, an external yarn store is available, for example in the form of one or more colour bobbins with a large amount of that yarn. For the different yarns (yarn type and/or yarn colours), yarn stores are also continuously available in the respective yarn storage tubes (2). These stores are supplemented automatically, depending on yarn consumption, by means of one or more movable yarn loaders (3).

(15) The number of yarn storage tubes corresponds substantially to the number of colours that one wishes to have available at a certain position viewed in the width in the fabric multiplied by the number of positions where one wishes to add the yarns in this way. For a machine for weaving pile fabrics, this number may normally correspond to the number of bobbin spindles that were traditionally provided for the pile yarns.

(16) The yarn storage device (1) according to the invention shown in FIG. 1 comprises a frame (6), on which a number of hollow yarn storage tubes (2), of equal length with open ends and with an identical square cross-section, are grouped in several horizontal rows above one another into a substantially rectangular assembly. The various yarn storage tubes (2) are adjacent to each other or have common partition walls. Each yarn storage tube (see also FIGS. 4 and 5) has closed side walls that enclose an interior space (2c), and has a supply opening (2b) at the front end, via which the yarn store can be supplemented, and a discharge opening (2a) at the rear end, via which the yarn leaves the yarn storage tube (2) and is led to a yarn processing machine (not shown in the figures). Depending on yarn consumption, the yarn is withdrawn from the yarn store and moved to the yarn processing machine. The yarn storage tubes may be mounted slightly inclined, wherein the discharge opening (2a) is higher than the supply opening (2b). Preferably, however, they are mounted horizontally.

(17) The open ends of these yarn storage tubes (2) lie in each case in one and the same vertical plane. On the side with the supply openings (2b), a yarn loader (3) is mounted on a platform that is movable in a vertical plane by an x-y motion system. The height position of the yarn loader (3) is determined by a first rack-and-pinion drive (4a) wherein the rack is connected to a vertical profile (4b) and the pinion is driven by means of an electric motor-reducer combination. The horizontal position of the whole, including the profile, is determined by means of a second rack-and-pinion drive (5a), wherein the rack is connected rigidly to a horizontal profile (5b) that forms part of the frame (6).

(18) A winding holder (7) is provided in the interior space (2c) of each yarn storage tube (2). The winding holder (7) is an elongated and symmetrical whole that is supported centrally in the yarn storage tube, running along the longitudinal axis of the yarn storage tube (2). A winding holder (7) of this kind is shown in FIGS. 2 and 3.

(19) The winding holder (7) comprises a winding-up part (7a) consisting of a base part (10) that carries a number of spaced-apart arms (11) that extend towards the end in the longitudinal direction of the winding holder (7). The arms (11) are provided on their ends, on the outer sides directed away from each other, with hook-shaped elements (11a). The yarn is wound on the arms (11) by the yarn loader (3), and the hook-shaped elements (11a) ensure that yarn cannot slip off of the arms (11). The arms define a winding-up surface with a diameter (D.sub.1) of about 35 mm.

(20) The winding-up part (7a) undergoes a transition via a conical intermediate part (7b) with a gradually decreasing diameter (D.sub.2), into a long cylindrical part (7c)—the holder body (7c) that is provided in order to carry the supply of yarn in the form of windings that are wound round it. This holder body (7c) has a constant diameter (D.sub.3) that is less than the diameter (D.sub.1) of the winding-up part (7a). This diameter (D.sub.3) of the holder body (7c) is about 25 mm. The yarn windings, which are formed on the winding-up part (7a) with a diameter of roughly 35 mm, are pushed along by the addition of new windings until they leave the winding-up part (7a) via the intermediate part (7b) and arrive on the holder body (7c). The yarn windings, with their original winding diameter of about 35 mm, thus end up on the holder body (7c) with a diameter of about 25 mm, so that they are located round holder body (7c) in a very loose state. The outer surface of the holder body (7c) forms a holder surface (9) for holding the yarn windings.

(21) In the embodiment shown in FIGS. 2, 3, 6, 7a and 7b, there is transition of the other end of the holder body (7c) via a conical transition part (7d) into a cylindrical unwinding head (7e) with a diameter (D.sub.5) that is greater than the diameter (D.sub.3) of the holder body (7c). The diameter (D.sub.4) of the conical transition part (7d) gradually increases towards the unwinding head (7e), from the left-hand end thereof, where the diameter (D.sub.4) is equal to the diameter (D.sub.3) of the holder body (7c) to the right-hand end thereof, where the diameter (D.sub.4) is equal to the diameter (D.sub.5) of the unwinding head (7e).

(22) The surface of the transition part (7d) forms, relative to the surface (9) of the holder body (7c), an angle (α) of about 20°, as indicated in FIG. 3.

(23) As shown in FIGS. 4 and 5, each winding holder (7) can be placed in a position of rest (I) the position of the lower winding holder (7) in FIGS. 4 and 5—wherein the winding-up part (7a) is largely located in the interior space (2c) of the yarn storage tube (2), whereas the unwinding head (7e) is largely located outside the yarn storage tube (2), and each winding holder (7) can also be placed in a winding-up position (II) the position of the upper winding holder (7) in FIGS. 4 and 5—wherein the winding-up part (7a) is largely located outside the interior space (2c) of the yarn storage tube (2), whereas the unwinding head (7e) is largely located within this interior space (2c). If the winding holder (7) is placed in the winding-up position (II), the yarn loader (3) can wind yarn on the winding-up part (7a), in a manner similar to that described in EP 2721204. During winding-up of yarn, supply of yarn to the yarn processing machine can continue without any problems.

(24) In FIG. 6, it is shown how a winding holder (7) is supported at the level of the unwinding head (7e) because a brush element (12) surrounds the unwinding head (7e). The thin hairs of the brush are sufficient to support the winding holder (7) in an ideal operating position, and are also bent very easily through contact with the yarn that is being unwound, so that the yarn can easily be pulled past the brush, since this only requires a very small unwinding pulling force. The brush element (12) can be supported at the level of the discharge opening by the sidewalls of the yarn storage tube (2).

(25) Support may also be contactless (see FIGS. 7a, 7b and 7c), by providing the structures (14), which in the vicinity of the unwinding head (7e) are for example fastened to the side walls of the yarn storage tube (2), with first magnets (13a), and providing the unwinding head (7e) with an elongated cylindrical supporting part (21) extending along the longitudinal axis (8) with respective second magnets (13b), (13c) in two places apart from one another in the longitudinal direction, wherein the first magnets (13a) and the second magnets (13b), (13c) have mutually repulsive poles. The magnetic forces ensure that the winding holder (7) is held in the ideal operating position at the level of the unwinding head (7e). The winding holder (7) is as it were held in a floating position.

(26) Because the winding head (7e) must be adequately supported both in the position of rest (I) the position in FIG. 7a and in the winding-up position (II) the position in FIG. 7b, second magnets (13b), (13c) are provided in two different places on the supporting part (21) of the unwinding head (7e).

(27) To guide the yarn on its unwinding path, a guide tube (15) may also be provided, as shown in FIG. 8. The winding holder (7) does not comprise in this case an unwinding head as in the embodiments described above according to FIGS. 2 and 3, but the holder body (7c) has a transition at the end into a transition part (29) with a symmetrical shape and a first part (29a), the diameter of which is at first roughly equal to the diameter of the holder body (7c), and then gradually increases to a maximum diameter. At the point where the transition part (29) reaches its maximum diameter, it undergoes transition via a rounding (16) to a second part (29b) with gradually decreasing diameter. The yarn is led past the transition part (29) directly via the guide tube (15) to the yarn processing machine.

(28) The guide tube (15) has a horizontal initial part (15a), the open end of which forms the inlet (17). This inlet (17) is located above said rounding (16) of the transition part (29). The initial part (15a) starts from the transition part (29) and then, via a downward bend that makes an angle (β) of about 20°, transitions into a downward slanting straight portion (15b) and finally, via a bend which again makes an angle (β) of about 20°, transitions into a horizontal end part (15c) that extends along a longitudinal axis that coincides with the extension of the longitudinal axis (8) of the winding holder (7). The open end of the horizontal end part (15c) forms the outlet (18) of the guide tube (15).

(29) The yarn runs from the winding holder (7) over the transition part (29) to the inlet (17) of the guide tube (15) and is led away from the holder surface (9). The yarn leaves the guide tube (15) via the outlet (18) and is led further to the yarn processing machine.

(30) The tubular element (15) is fixed on a rotatable shaft (20) that is mounted on bearings at the level of the end of the transition part (29) and at the level of a rigidly mounted component (19), for example connected to the yarn storage tube. This rotatable shaft (20) extends along the longitudinal axis (8) of the winding holder (7). Due to the unwinding pulling force exerted on the yarn, the guide tube (15) and the shaft (20) can be caused to rotate, wherein the inlet (17) of the guide tube (15) describes a turning circle with a diameter (D.sub.6) as indicated in FIG. 8.

(31) To allow the winding holder (7) to slide between the position of rest (I) and the winding-up position (II), the mounting of the guide tube (15) is movable axially at the level of the rigidly mounted component (19), for example using a plain bearing or a needle bush, or by providing an axially slidable connection.

(32) The yarn that is unwound from the holder body (7c) via the transition part (29) and is supplied to the yarn processing machine has, after leaving the transition part (29), a smooth, gradually changing course through the tubular element (15), without abrupt transitions, so that high stress peaks are avoided.

(33) A similar arrangement can be seen in FIGS. 9a and 9b. The holder body (7c) is again connected to a cylindrical transition part (22) with a first portion (22a), the diameter of which gradually increases from the end connected to the holder body (7c)—where the diameters of the holder body (7c) and the transition part (22) are almost identical —to the other end, and with a second portion (22b) connected to that other end, with a constant diameter that is roughly equal to the largest diameter of the first portion (22a).

(34) Beyond the transition part (22), a substantially disk-shaped unwinding element (23) is provided on a shaft (24) that is mounted on bearings so that the unwinding element (23) is rotatable about an axis that coincides with the longitudinal axis (8) of the winding holder (7). The unwinding element (23) comprises a feed-through eye (25) for the yarn in the vicinity of its peripheral edge.

(35) The yarn is moved past the transition part (22) via the feed-through eye (25) to the yarn processing machine. Due to the unwinding pulling force exerted on the yarn, the unwinding element (23) will rotate about the axis (8), wherein the yarn in the feed-through eye (25) describes a turning circle with a diameter (D.sub.7) as indicated in FIG. 9b.

(36) In the yarn storage tube (2), elongated cylindrical guide rollers (27) are provided in respective elongated holders (26), so that the guide rollers (27) are in contact, at different locations distributed over the perimeter of the unwinding element (23), with the outer surface of the unwinding element (23), and wherein these locations are distributed in such a way that seen on a cross-section of the unwinding element (23) as in FIG. 9a two diametrically opposite locations lie on a first centre line of the circular cross-section of the unwinding element (23), and the third location lies on a second centre line that is perpendicular to the first centre line.

(37) The guide rollers (27) extend in the longitudinal direction (8) of the yarn storage tube (2) and the winding holder (7) and are for example fixed to the walls of the yarn storage tube (2). The guide rollers (27) are connected at both ends by means of a small shaft (28) to their respective holder (26), so that the guide rollers (27) are rotatable about their longitudinal axis. Because the unwinding element (23) is in contact with the rotatable guide rollers (27), the unwinding element (23) can rotate more easily about the axis (8). When there is an axial movement of the winding holder (7), the unwinding element (23) slides over the elongated guide rollers (27). As a result, the winding holder (7) is movable axially between a position of rest (I) wherein the winding-up part (7a) is largely located in the interior space (2c) of the yarn storage tube (2) and a winding-up position (II) wherein the winding-up part (7a) is largely located outside the interior space (2c) of the yarn storage tube (2). In both positions, the transition part (22) and the unwinding element (23) are located within this interior space (2c).

(38) In the embodiments presented in FIGS. 6, 7a and 7b and FIGS. 9a and 9b, after leaving the unwinding head (7e) or the unwinding element (23) the yarn preferably follows the same path as in the embodiment according to FIG. 8. For this, the yarn is preferably led in the direction of a point that is some distance from the unwinding head (7e) or the unwinding element (23) and lies in the vicinity of the extension of the longitudinal axis (8) of the winding holder (7), preferably lies on the extension of this longitudinal axis (8), and wherein the yarn is led in such a way that, after leaving the unwinding head (7e) or the unwinding element (23), the yarn has a smooth, gradually changing course on its path to said point. A guide eye, for example, may be positioned at said point.

(39) In some yarn processing machines that are provided, for yarn supply, with a yarn storage device according to the present invention, it may be very advantageous to provide additionally a yarn tension system, wherein the yarn to be supplied is given a certain tension profile, wherein this may or may not be done individually per yarn. A yarn tension system of this kind is for example a system as described in WO 2017/077454 A1.

(40) It may moreover also be very advantageous to combine the yarn storage device according to the present invention with a yarn feeding device, which is provided in order to determine, during weaving, the amount of yarn supplied, in particular the amount of pile yarn supplied, wherein the yarn supply per yarn can be determined individually or for several yarns together.