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(11) | EP 1 243 543 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Device for controlling yarn unwound from a reel |
| (57) The device comprises a plurality of flexible linear units (17) hanging and subjected
to the force of the weight of at least one gravity body (18) and which surround at
least in part the windings of yarn on a reel (R) and docilely contain the windings,
without obstructing unwinding of the free end of the yarn, which is pulled by a machine
or loom supplied by the reel, said at least one gravity body (18) being mobile and
suspended so to ensure the constant containment of windings of yarn of the reel (R)
progressively as the diameter of the reel is reduced, keeping constantly the correct
tension of said flexible hanging units (17). |
[0002] The device according to the invention can be applied to textile machines, knitting machines, looms and the like, which during operation require unwinding of yarn collected in the form of a reel.
[0003] A reel consists of a tube, which can be either cylindrical or conical, on which a thread or yarn is wound forming windings in the form of a cylinder or frustum of a cone. The surface windings tend to loosen and slip downwards, falling in part also under the base of the reel during pauses when unwinding the yarn from the reel. This obstructs the regular unwinding of the yarn. The unwound yarn is subjected to irregular tension, which determines incorrect supply, and - in some cases - breaking, whereby causing manufacturing defects in the products made with the yarn, particularly when the reel looses its regular winding configuration.
[0004] On the other hand, the yarn accumulated at the bottom of the reel tends to get twisted, whereby causing additional problems in supplying the textile machine, knitting machine, loom or the like. This invention intends to solve such shortcomings.
[0005] Consequently, the main object of the invention is to provide a device for controlling yarn unwound from a reel which prevents the loosening and downwards slipping of superficial windings, with consequent irregular tension and possible twisting of the yarn which is unwound from the reel.
[0006] An additional object of the invention is to provide a device for controlling the yarn unwound from a reel whose application is universal in relation to the shape and size of the reels of yarn, whose structure is simple and whose operation is safe and effective.
[0007] According to the invention, these objects are achieved thanks to a device for controlling yarn unwound from a reel having the essential characteristic specifically recited in the main claim.
[0010] The invention will now be described, by the way of example only, with reference to the accompanying drawings wherein:
- figure 1 is a perspective view of the device for controlling yarn unwound from a reel according to a simplified embodiment of the invention;
- figure 2 is a view similar to that of figure 1 with reel of yarn and flexible wires partially wound on the reel omitted for the sake of illustrative clarity;
- figures 3 and 4 are perspective details on a larger scale of detail III in figure 2 in which a support for flexible wires partially wound on the reel is shown fitted in the position of use (figure 3) and disassembled for replacing a reel of yarn, respectively, in the device according to the invention (figure 4);
- figures 5 and 6 are perspective views, from the top and from the bottom, respectively, of a removable support for centering and fastening a reel of yarn in the device according to the invention.
[0011] In the drawings, numeral 10 (figures 1, 2) generally indicates a device for controlling yarn unwound from a reel according to a simplified embodiment of the invention.
[0012] Said device 10 essentially comprises a pedestal 11, for example a metal plate, from which a tubular column vertical support 12, for example made of metal, rises. A supporting arm 13, essentially shaped as an reversed "L", for example made of metal, is with its vertical arm 13.1 inserted and telescopically sliding in said tubular column support 12. Removable fastening means (pressure screw) 14 is provided to fasten the branch 13.1 of the arm 13 in different positions of telescopic extension with respect to the column 12, so to arrange the other horizontal branch 13.2 of said arm 13 at different heights with respect to the pedestal 11.
[0013] A supporting ring 15, for example made of plastic material, overhangs from the free end of said branch 13.2 of the support arm 13, the axis of the ring being essential vertical and falling substantially in the center of said pedestal 11. Said ring 15 centrally supports a coaxial ceramic material thread guide bushing 15.1. Furthermore, the upper face of said ring 15 is concave, with a pattern which is considerably slanted from the edge to the center (figures 3, 4). Radial slots 15.2 are provided in said ring 15 at regular intervals, for example eight slots at intervals of approximately 45°.
[0014] A supporting plate 16, for example metallic, is arranged in raised position by means of an axial column 16.1, also metallic, on a pedestal 11, coaxially with respect to said supporting ring 15, which hangs over said plate 16 at a distance which is higher than the height of a reel of yarn.
[0015] Said plate 16 is provided with a plurality of radial bored grooves 16.2, open on the edge of the plate in an arrangement which substantially corresponds, by number and position, to that of the slot 15.2 in the supporting ring 15.
[0016] An essentially cylindrical axial body 16.3, for example metallic, raises from the center of the plate 16. Said body 16.3 and said plate 16 are removeably fastened to the top of the column 16.1.
[0017] A plurality of flexible hanging wires 17 (figure 1), for example made of synthetic resin, hang at regular intervals with respect to the supporting ring 15, one for each slot 15.2 in the ring, and support a common gravity ring 18 in the lower part, for example metallic, hanging under the supporting plate 16, which is slidingly and coaxially arranged with respect to the column 16.1.
[0018] Each hanging wire 17 is arranged through a respective groove 16.2 in the plate 16 and tends to act as a plumb by effect of the weight of the gravity ring 18.
[0019] Each hanging wire 17 is also arranged through the corresponding slot 15.2 in the supporting ring 15. A retaining body (not illustrated) is fastened to the upper end of each hanging wire 17, for example a lead ball, which prevents pulling out from the slot by effect of gravity. By effect of this arrangement, each hanging wire 17 can freely move in a radial direction of the supporting ring 15 for the entire length of the respective slot 15.2 and in the corresponding radial direction of the plate 16 along the respective groove 16.2.
[0020] A reel of yarn R (figure 1) is removeably fastened on the supporting plate 16 by means of a fastening and centering support 19 (figures 5, 6).
[0021] Said support 19 comprises a plate base 19.1, for example made of plastic material, for supporting the reel R. Said plate base 19.1 is provided with a plurality of bored radial grooves 19.2, open in correspondence to the external circumferential edge and corresponding, by number and arrangement, to the bored grooves 16.2 in the supporting plate 16. Specifically, said plate base 19.1 presents an inferior axial cavity 19.3, in which an axial body 16.3 over said plate 16 is coupled by shape and/or force. In the coupled condition, a number of external radial teeth of said axial body 16.3 engage corresponding radial grooves in said axial cavity 19.3 so to prevent the rotation of said plate base 19.1 with respect to the supporting base 16, whereby also identifying a correct relative position of said plate base 19.1 in which the grooves 19.2 correspond to the grooves 16.2 in said plate 16.
[0022] A plurality of flat springs 19.4, for example essential V-shaped whose branches are specularly symmetric with respect to the axis of the plate base 19.1 and acting by expansion, stretch upwards from the central zone of said base 19.1. The branches of said flat springs 19.4 are inserted in the tube (not illustrated) of the reel R to be arranged on the plate 16 so to ensure the reel itself in correctly centered position, regardless of the dimension, shape and type of tube on which the reel is wound.
[0023] As clearly apparent in figure 1, in the device 10 according to the invention, the arrangement of flexible hanging wires 17 uniformly surround the windings of yarn on the reel R and docilely contain the windings, without obstructing the unwinding of the free end of the yarn (indicated with a dotted line in figure 1), which passes through the thread guide bushing 15.1 and is pulled by the machine or loom supplied by the reel. The gravity ring 18 is suspended and free to slide axially with respect to the column 16.1, ensuring the constant containment of the windings of yarn on the reel R, progressively as the diameter of the reel is reduced, keeping the correct tension of the hanging wires 17 correct at all times. In this way, said flexible wires 17 are automatically adapted to the radial dimension of the reel R being used, each running with its upper end along the respective radial slot 15.2 in the supporting ring 15 and, on the base of the reel R, the respective radial grooves 16.2 and 19.2 in the supporting plate 16 and in the fastening support 19, in a centripetal direction and correctly guided.
[0024] On the other hand, such radial mobility of the flexible hanging wires 17 with respect to the supporting ring 15 and to the supporting plate 16 is exploited to adapt the wires 17 to the different types and dimensions of the new reels to be arranged in the device 10.
[0025] According to an advantageous characteristic of the invention, the supporting ring 15 is formed by two half rings 15.3, 15.4 (figures 3, 4), which are removeably coupled, in order to facilitate assembly of a new reel R on the supporting plate 16. One half ring 15.3 is fastened on the end of the horizontal branch 13.2 of the supporting arm 13 and carries the thread guide bushing 15.1. The other half ring 15.4 is mobile and carries a pair of permanent magnets, which are partially housed in the respective seats 15.5 and which co-operate with corresponding permanent magnets partially housed in the respective housings 15.5 in the fixed half ring 15.3, when the two half rings 15.3, 15.4 are reciprocally and correctly arranged, so to removeably fasten said mobile half ring 15.4 with respect to the fixed half ring 15.3. Some reference pins 15.6, projecting from the fixed half ring 15.3, co-operate with the corresponding housing holes 15.7 in the mobile half ring 15.4 to identify the correct coupling position of said parts.
[0026] By means of said arrangement, when a new reel of yarn is to be arranged in the device 10, the mobile half ring 15.4 is preliminary separated from the fixed half ring 15.3. At the same time, the respective flexible hanging wires 17 are removed from the supporting plate 16 along with the mobile half ring 15.4, whereby freeing access for the new reel to the supporting plate.
[0027] Furthermore, the arrangement of the flexible wires 17 hanging from the supporting ring 15 can be adjusted in height by telescopic sliding of the vertical branch 13.1 of the L-shaped support 13 with respect to the column support 12 so to adapt to reels of yarn of different heights.
[0028] Furthermore, the device 10 according to this embodiment of the invention is provided with braking means 20 of the yarn being coming out from the thread guide bushing 15.1 (figures 1, 3, 4). Said braking means 20 are fixedly supported on the upper free end of the horizontal branch 13.2 of the supporting arm 13 in a position over the thread guide bushing 15.1. The breaking means comprise a pair of thread braking plates 21, reciprocally opposed and rotating on an axis which is substantially horizontal while they are yieldingly pressed one against the other by means of a coaxial elastic unit 22. The yarn coming out from the thread guide bushing 15.1 passes between said opposed plates and its tension is controlled by regulating the elastic load applied to the plates by means of the elastic unit 22.
[0029] Moreover, the device 10 comprises means 30 for controlling the presence/lacking of yarn from the reel R. Said controlling means 30 comprise a detecting arm 31, over said braking means 20 and pivoting, for example under elastic load, with respect to an essentially horizontal axis. Said detecting arm 31 is held normally in sliding contact with the yarn coming out from the thread guide bushing 15.1 and said braking means 20. If the yarn is missing, the detecting arm 31 is no longer contrasted by the yarn and is induced to pivot on said horizontal axis whereby determining a respective electric switch-over of a corresponding electric/electronic position detector (for example, an electric switch), so to signal the lack of yarn to a convenient electric/electronic control unit of the machine or loom supplied with the yarn from the reel R arranged in the device 10. In this way, the machine or loom can be timely stopped if the yarn breaks or ends.
[0030] As results from the description above, the device according to the invention prevents the windings being unwound from a reel of yarn from loosening and slipping downwards and getting caught in part also under the bottom of the reel in a simple and effective way. Consequently, the device according to the invention reduces machine or loom stops due to breaking of the yarn and also ensures correct and constant tensioning of the yarn, preventing undesired twisting during unwinding from the reel. This increases productivity and manufacturing of the machine or loom as well as the quality of the products.
[0031] Naturally, numerous changes can be implemented to the invention herein envisaged without departing from the scope of the present invention and consequently the industrial property domain.
[0032] Consequently, for example, each flexible hanging wire can carry a respective gravity body on its lower end.
[0033] Also only two flexible hanging wires, for example arranged on opposite bands with respect to the reel of yarn, can be sufficient to ensure correct winding of the yarn on the reel, both while unwinding the yarn and during pauses in unwinding.
1. Device for controlling yarn unwound from a reel characterised in that it comprises a plurality of flexible linear units (17) hanging and subjected to the
force of the weight of at least one gravity body (18) and which surround at least
in part the windings of yarn on a reel (R) and docilely contain the windings, without
obstructing unwinding of the free end of the yarn, which is pulled by a machine or
loom supplied by the reel, said at least one gravity body (18) being mobile and suspended
so to ensure the constant containment of windings of yarn of the reel (R) progressively
as the diameter of the reel is reduced, keeping constantly the correct tension of
said flexible hanging units (17).
2. Device for controlling yarn unwound from a reel according to claim 1, characterised in that it comprises a supporting ring (15) over and essential coaxial with respect to a
reel of yarn (R) arranged on a supporting plate (16) raised over a base (11), and
in that a plurality of flexible hanging linear units (17) hang from said supporting ring
(15) and inferiorly support at least a gravity body (18), suspended and mobile under
said supporting plate (16), and in that each flexible linear unit (17) is arranged through in a respective radial groove
(16.2) of said plate (16) and tends to behave as a plumb by effect of the weight of
at least one gravity body (18).
3. Device for controlling yarn unwound from a reel according to claim 2, characterised in that the upper face of said ring (15) is concave and radial grooves (15.2) are arranged
in said ring (15), and in that each flexible hanging linear unit (17) is arranged through a corresponding slot (15.2)
in said supporting ring (15) and carries a retaining body fastened to its upper end
which prevents pulling out by effect of gravity with respect to the slot, while it
permits to said linear unit to translate freely in a radial direction of the supporting
ring (15) for the entire length of the respective slot (15.2) and in the corresponding
radial direction of said supporting plate (16) along a respective through groove (16.2),
so that the flexible hanging linear units (17) are automatically adapted to the radial
dimension of the reel (R) being used, each running with its upper end along the respective
radial slot (15.2) in the supporting ring (15) and the respective radial groove (16.2)
in the supporting plate (16) at the bottom of the reel (R), in a centripetal direction
and correctly guided, said radial mobility of the flexible hanging linear units (17)
with respect to the supporting ring (15) and to the supporting plate (16) permitting
to adapt the units (17) to different types and dimensions of the new reels arranged
on the supporting plate (16).
4. Device for controlling yarn unwound from a reel according to claim 1, 2 or 3, characterised in that said supporting plate (16) is supported by an axial column (16.1) and in that said at least one gravity body (18) consists of a common gravity ring (18), suspended
with respect to the lower ends of the flexible hanging linear units (17) under the
supporting plate (16) and is coaxially sliding with respect to the column (16.1).
5. Device for controlling yarn unwound from a reel according to any claim above, characterised in that said supporting ring (15) centrally supports a coaxial thread guide bushing (15.1),
for example made of ceramic material.
6. Device for controlling yarn unwound from a reel according to any of the claims from
2 to 5, characterised in that said supporting ring (15) is formed by two half rings, one of which is fixed (15.3)
and the other is mobile (15.4), reciprocally and removeably coupled, so that when
a new reel of yarn is to be arranged on said supporting plate (16), the mobile ring
(15.4) is preliminarily separated from the fixed half ring (15.3) along with the respective
flexible hanging linear units (17) which are removed from the supporting plate (16),
whereby freeing the access to the supporting plate for the new reel.
7. Device for controlling yarn unwound from a reel according to any claim above, characterised in that said plurality of flexible hanging linear units (17) is supported so to be adjustable
in height by a support (12, 13, 13.1, 13.2) which is telescopically extensible and
retractable in the vertical direction to adapt to the reels of yarn of different heights.
8. Device for controlling yarn unwound from a reel according to any claim above, characterised in that a reel of yarn (R) is removeably fastened on said supporting plate (16) by means
of a fastening and centering support (19).
9. Device for controlling yarn unwound from a reel according to claim 8 and to any claim
from 2 to 4, characterised in that said support (19) comprises a plate base (19.1) to support the reel and which is
provided with a plurality of through radial grooves (19.2) open in correspondence
to the circumferential external edge and corresponding by number and arrangement to
the through grooves (16.2) of said supporting plate (16), said plate base (19.1) presenting
an inferior axial cavity (19.3) in which an axial body (16.3) projecting over said
plate (16) is coupled by shape and/or force, said axial body prevents the rotation
of the plate base (19.1) with respect to said supporting plate (16), whereby identifying
a correct relative position of said plate base (19.1) in which the grooves (19.2)
correspond to the grooves (16.2) in said plate (16).
10. Device for controlling yarn unwound from a reel according to claim 8 or 9, characterised in that said support (19) comprises a plurality of flat springs (19.4) acting by expansion
and protruding upwards in a symmetric arrangement with respect to the axis of said
base (19.1), said flat springs (19.4) being inserted in the tube of a reel (R) to
be arranged on the plate (16), so to ensure the correct centered position of the reel
itself.
11. Device for controlling yarn unwound from a reel according to any claim above, characterised in that it comprises means (20) for braking the yarn supplied by said reel (R).
12. Device for controlling yarn unwound from a reel according to any claim above, characterised in that it comprises means (30) for controlling the presence/lacking of yarn supplied by
said reel (R).