EP0843642B1

EP0843642B1 - Device for guiding thread during unwinding from spools or bobbins

Info

Publication number: EP0843642B1
Application number: EP97922022A
Authority: EP
Inventors: Dante Zambelli
Original assignee: Tessilgraf Srl
Current assignee: Tessilgraf Srl
Priority date: 1996-05-17
Filing date: 1997-05-02
Publication date: 2002-08-07
Anticipated expiration: 2017-05-02
Also published as: AU2787497A; EP0843642A1; DE69714550D1; WO1997044271A1; ITMO960061A1; IT1287432B1

Abstract

The device aims to reduce the bulk and the complexity of creels, i.e., of the supports of the spools (12) which are specifically installed proximate to weaving machines, caused by the path of the thread unwinding longitudinally from the spool (12) and subjected to tension variations and to lateral flapping; to shorten the path of the thread (14); to facilitate changing the spool (12); and to allow a wider range of coupling possibilities between te pivot and the core (13) of the spool; the device consisting in replacing the supporting pin of the spool (12) with a sleeve (2) wherein the thread (14) is passed in the opposite direction with respect to the direction wherein it unwinds longitudinally from the spool (12) and is tensioned by means of tensioner means (16) and locked by locking means (17) as soon as it leaves the sleeve (2), which is supported directly on the framework (1) of the weaving machine; a ring (4) allowing to adjust the diameter for the coupling of the elastic laminae (8) to the core (13) of the spool.

Description

Technical Field

The present invention relates to a device for guiding thread during unwinding from spools or bobbins, i.e., to a set of elements which are adapted to orientate the thread that unwinds from supports or cores in order to assume a new preset direction, both to simply transfer the thread for example from a spool to one or more bobbins and to feed the thread to the weaving loom or to any machine adapted to manufacture fabrics, materials, knitted products, and the like, more briefly referenced to as weaving machine hereinafter.

Background Art

The prior art includes supports known as creels for supporting, often rotatably, the spools and/or bobbins in a position which is spaced from the point of use: the core of the spools or bobbins, i.e., the hollow tubular support whereon the thread is wound, is inserted on a pin or pivot which is rigid or provided with an elastic expandable element to adapt, albeit not adjustably, to the hole of cores having different diameters.
The thread can unwind transversely, i.e., tangentially with respect to the axis of the spool or bobbin, or longitudinally, around the imaginary continuation of the axis of the spools or bobbins.
In the first case, since the diameter of the spool or bobbin gradually decreases as the thread unwinds, undesirable tension variations occur in the thread and must be eliminated by means of another device, particularly to avoid rewinding defects or defects in the feeding of the loom or weaving machine in general: for example, by resorting to a braking drum coupled to the core of the spool or bobbin in order to correct the variations in the rotation rate of the spool or bobbin during thread unwinding as the unwinding diameter gradually decreases; the single term "spool" is used hereinafter, instead of "bobbin", to indicate the mass of thread wound around a core or support in general, regardless of its shape or dimensions.
In the second case, the longitudinal unwinding of the thread allows to reduce the tension variation caused by the decrease in the unwinding diameter: this, however, is achieved along a rather long thread path which sometimes occupies an unacceptable amount of space, over which the thread is subjected to tension variations and to flapping: in any case, it is necessary to adopt auxiliary devices for the elastic tensioning and locking of the thread, such as the so-called thread clamps, distributed downstream of the feeder or accumulation device.
In any case, the need to use particular braking devices or, respectively, to have large spaces equipped so as to allow the thread to unwind without significant tension variations, without the damaging effects of flapping, and without twisting is a considerable economical burden.
In fact, in addition to having to interpose a considerable distance, for example even more than one meter, between the creel supporting the spools and the weaving machine in the preferred longitudinal unwinding of the thread from the spool, it is also necessary to provide, laterally with respect to the path of each thread, vertical partitions adapted to prevent interference between adjacent threads, caused by the transverse flapping whereto they are subjected when traction varies; it is also necessary to provide the tubular guide for the entry of the thread into the weaving machine with a peripheral shield, shaped for example like a convex annulus, to prevent twisting of said thread around the guide; this not only entails a considerable bulk but also leads to a significant increase in costs and to considerable difficulty for the operator, who is forced to manually change the spools by inserting his hands and arms between the vertical partitions affected by the flapping of the threads, with the risk of interfering therewith and of causing breakages and downtimes.
Moreover, in the feeding of a weaving machine requiring spool replacement to allow working continuity, the presence of the operator becomes indispensable when the trailing end of the spool about to be emptied must be tied to the end of the still-intact spool, and this entails particular scheduling of the operator's presence and the commitment of said operator in order to avoid interrupting the work of the weaving machine, leading to an increase in costs.
Moreover, difficulties are observed in adapting the outside diameter of the supporting pin or pivot of the spool and the inside diameter of the core with respect to each other, these difficulties being caused by the fact that it is not possible to set the maximum diameter of said elastic element, leading to instability in support and considerably limiting the range of interchangeability of the spools on a same pivot or pin.
This prior art is susceptible of considerable improvements and changes as regards the possibility of eliminating or considerably reducing the above-described drawbacks.
Examples of prior art devices are available from the documents US-A-1 962 681 and WO 92-13123.

DISCLOSURE OF THE INVENTION

A principal aim of the present invention is to provide a device adapted to guide single- or multiple-filament thread during its unwinding from the spools in such a direction as to allow the minimum bulk and means for its unwinding and for reaching the weaving machine; another first aspect of the same problem is the use of a limited number of means for locking and tensioning the thread, arranging said means compactly and efficiently and so as to have a minimum bulk; a further second aspect of the same problem is to continuously feed the weaving machine by passing the feed from one spool to another spool, operator intervention being allowed over a wide time interval prior to the last moment wherein the trailing end of one thread can be tied to the leading part of the next thread; a further final aspect of the same problem is to ensure that the cores of the spools have a better elastic support on the pivot or pin about which the thread is unwound by pulling, over a wider range of interchangeability of the spool cores on said pivot or pin.
The present invention solves the above problem by adopting a thread unwinding path which lies substantially along the axis of the spool but in an opposite direction with respect to the conventional longitudinal unwinding direction, said path being provided by a guide constituted by a tubular through element, which is supported in any manner and is adapted to constitute a rotational support for said core, the thread to be unwound being inserted in said tubular element from its front opening so as to exit from its opposite opening: a thread guiding rod being provided for this purpose, said rod having, in a front region, a hook for engaging the thread and optionally a rear grip when it is necessary to manually insert said hook into said tubular through element so as to move beyond its opening and pull the thread backwards beyond the exit opening; as regards solving the further first aspect of the problem, means for tensioning and locking the thread being advantageously provided which are supported where said thread exits from said opening upstream of the user; as regards solving the second further aspect related to feeding the weaving machine with spool changing, a guided path of the thread is provided which is parallel to the axis of the spools but lies outside the spools, advantageously in an intermediate position between their axes, by means of a fixture-equipped tubular element; as regards solving the further last aspect of the same problem, a set of convex elastic laminae for the adjustable support of the spool core is inserted around the spool supporting pivot or pin.
The advantages achieved by the present invention are: simplification of the devices required to unwind the thread from the spools; reduction of the space required for the unwinding of the thread; elimination of thread flapping; elimination of the specifically-provided creels near the weaving machine; accordingly, the spools can be supported directly on the machine, consequently reducing manufacturing, installation and operating costs and bulk; compactness of the thread tensioning and locking means; more uniform tension of the thread; more practical thread locking for the operator and better position and use of the operator during spool changing; higher productivity; the possibility to perform fine adjustment of the support for the spool core and to provide a wider interchangeability range both in case of fixed coupling and in case of rotary coupling between the spool core and the supporting pivot or pin.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiment of the present invention is illustrated in figure 11, the further drawings are merely for explanation, wherein:
figure 1 is a partial side view of a support advantageously belonging to the weaving machine and provided with spools or bobbins of thread which have, for example, a cylindrical or frustum shape and are arranged for example horizontally;
figure 2 is a partial enlarged-scale and partially sectional view of figure 1;
figure 2a is a side view of an extractor or thread guide adapted to engage the end of a portion of thread freshly unwound from the bobbin in order to insert it in the front end of a tubular element which constitutes a support for the corresponding spool and to extract it from the rear end of the tubular element;
figure 3 is a partial plan view of figure 1;
figure 4 is a partial left view of figure 1;
figure 5 is a partial view of figure 1, wherein the spools are arranged in a vertical alignment merely by way of example;
figure 6 is a partial side view of a supporting element with spools having parallel vertical axes;
figure 7 is a vertical sectional view of the embodiment of the present invention in the case in which the thread is unwound from a large primary spool, generally installed in the upper part of a support so as to directly feed the machine without dividing the thread among a plurality of smaller spools;
figure 8 is an elevation view of a set of large primary spools used as in figure 7;
figure 9 is a partially sectional side view of the direct feeding of the thread unwound from a spool according to the present invention to a weaving machine preceded by an accumulation device to prevent jerks every time the thread is pulled;
figure 10 is a side view of a set of accumulation devices fed according to figure 9;
figure 11 is a plan view of a device using the present invention to feed, for example, the accumulation device of a weaving machine by taking the thread uninterruptedly from a plurality of spools;
figure 12 is a sectional view, taken along the plane XII-XII of figure 11, illustrating the path of the threads through guiding elements interposed between the spool and the tubular guiding element during operation and before the emptying of one spool and the activation of the next spool.

WAYS OF CARRYING OUT THE INVENTION

The reference numeral 1 designates a framework supporting sleeves 2, i.e., tubular elements advantageously provided with a cylindrical axial hole 2a which are fixed for example to the framework by means of nuts 3; the reference numeral 4 designates a retention means, for example a ring, adapted to provide an abutment which is axially adjustable, for example by means of a threaded coupling on the sleeve 2 through an elastic means 5, for example a helical spring, which acts against a pusher disk 6 provided, in a front region, with a groove 7 to accommodate, in the groove, the rear ends of a set of elastic laminae 8 which are arranged circumferentially with respect to the sleeve 2 in a convex configuration and the opposite end whereof is correspondingly inserted in a groove 9 wherewith a front collar 10 is provided, the collar being coaxial to sleeve 2 and resting on an abutment element 11 which is fixed on the sleeve 2; the assembly constitutes an elastic expandable and contractible support for the spool 12; the reference numeral 13 designates the core for winding thereon the thread 14a so as to constitute the spool, the core being provided in a rear region with an open bottom 15 for the advantageous insertion of the disk 6 therein; the reference numeral 16 designates elastic tensioners for tensioning the thread 14, which are supplemented by an underlying means 17 for locking, advantageously on the extension of one of the elastic tensioners 16, the end of the thread, which is waiting to be inserted in a weaving loom; these means, known as thread clamps, being fixed on brackets 18 which are supported in any manner on the framework 1 and are advantageously located proximate to the exit hole of the sleeve 2, thus allowing to reduce bulk; the reference numeral 19 designates pairs of disks of the thread clamp, which elastically lock the thread 14 through the pushing action of an elastic means 20, for example a conical spring belonging to one of the thread clamps; the reference numeral 21 designates bushes for guiding the thread 14 that leaves the brackets 18; the reference numeral 22 designates the reed of the weaving loom or generally a part of the generic weaving machine; the reference numeral 23 (figure 3) designates a roller provided with grooves 24 for guiding and spacing the set of threads 14; the reference numeral 25 designates the hook of the thread guide rod, provided with a grip 26 for the optional manual insertion of the thread in the front part of the sleeve 2, 38 and for its extraction from the rear part thereof; the reference numeral 27 (figure 7) designates a large primary spool, which already constitutes a reserve for forming smaller spools, for directly dispensing the thread 14 to the weaving machine, supported on a part 28 of the frame of said machine or connected thereto; the reference numeral 29 (figure 11) designates a device for accumulating the thread arriving from the spool 12 by means of a cantilevered support 30 provided with tensioning means 31, advantageously taking up the thread along a zigzag path, in order to tension the thread 14, preventing its lateral flapping during unwinding before it enters the accumulation device; the reference numeral 32 designates a bridge between the plate 33 for supporting a sleeve with an corresponding through hole and at least one spool, and an annular flange 34 for connection to the rear part of the body of the accumulation device 29, which is in turn supported on a part 35 of the frame of the weaving machine or is connected thereto: the bridge, which is advantageously short, can also be curved and/or inclined in any way according to the preferred orientation of the axis of the spool with respect to the hole for entering the weaving machine; the reference numeral 36 (figure 11) designates a base for supporting two spools 12a and 12b which may have elastic adjustment means for insertion on the respective pivot or pin 37a and 37b which is fixed to one end of the supporting base 36 inside the core 13; since it is convenient to make the axes of said pivots or pins converge slightly, said base is accordingly constituted by two arms converging slightly at the center; the reference numeral 38 designates a fixture-equipped tubular element or sleeve which is fixed to said supporting base 36 in an intermediate position, conveniently at the centerline; the reference numerals 39 and 40 designate two arms which are opposite to each other and protrude from the middle-upper part of said sleeve 38 in order to respectively support the eyelets 41 and 42, which have (figure 12) a central hole 41a and 42a and a peripheral hole 41b and 42b connected to the central hole: the first one is central in order to guide the thread 43a unwinding from the spool 12a which is active, and the second one is eccentric in order to guide the thread 43b constituting the trailing end of the thread 43a, the latter being advantageously located in the lower position wherein the respective thread arrives; the reference numerals 44a and 44b respectively designate the thread which unwinds (when delivery occurs) from the spool 12b, passes through the central hole 42a, and the trailing end 44b of the thread 44a, which passes through the eccentric hole 42b; the reference numerals 45 and 46 designate two curved prongs which are opposite to each other and are fixed to the sleeve 38 in its lower part and are advantageously co-planar with respect to the arms 39 and 40 in order to redirect the trailing ends 43b and 44b of thread while waiting for complete unwinding from the respective spool, which is followed by the automatic extraction thereof; the reference numerals 47 and 48 designate two elastic flaps which are fixed laterally to the sleeve 38 in a position corresponding to the position of the two curved prongs 45 and 46, the free ends whereof, despite being slightly spaced from the sleeve, fit between the free ends of the prongs; said elastic flaps having the purpose of temporarily anchoring the trailing end 44b of the thread 44a during standby, the trailing end being then manually released when it must be manually tied to the thread of the spool which will replace the depleted one, in order to achieve uninterrupted feeding of the weaving machine; the reference numeral 49 designates a lower thread clamping element for anchoring thereto the trailing end 44b of the spool 12b which is standing by to replace the depleted spool 12a; the reference numeral 50 designates the knot formed between the thread 43b of the spool 12a during unwinding and the thread 44a of the spool 12b which is standing by; the reference numeral 51 designates an elastic flap fixed to the sleeve 38 in its upper part in order to anchor thereto the continuous thread generated by the tying of the end 43b together with the end 44a; the reference numeral 52 designates the curved front along which the thread having ends 43a and 43b advances before passing through the respective holes 41a and 41b, followed by the front 53, which forms the active thread 44a that replaces the depleted thread 43a, in order to be guided into the hole of the sleeve 38 and be tensioned by the tensioning means 31.
In the practical embodiment, the materials, the dimensions, and the constructive details may be different from those described but technically equivalent thereto without thereby abandoning the scope of the present invention.
The tubular element or sleeve 2 can also be rotatably coupled to the support 1, instead of being fixed thereto, and act as a pivot or pin if the thread unwinds tangentially with respect to the spool.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A device for guiding thread during unwinding from spools or bobbins, comprising an element (1, 36) for supporting the pivot or pin (2, 37, 37a) whereon, either directly or indirectly by means of an interposed elastic element, the core (13) of the spool or bobbin (12, 12a, 12b) from which the thread (14) unwinds is supported, said thread being subsequently tensioned by elastic tensioners (16, 31) for tensioning said thread and being lockable through elastic locking means, characterized in that the path of the thread (14) unwinding from said spool (12) is guided outside said spool (12, 12a, 12b) and substantially in the direction of the spool axis, inside a tubular element (38) supported so as to be parallel to the supporting pivot or pin (2, 37, 37a) of said spool (12, 12a, 12b).
A device according to claim 1, characterized in that the direction of the path of the thread (14) inside said tubular element (38) is opposite with respect to the direction of the longitudinal unwinding of said thread from the spool (12, 12a, 12b).
A device according to claim 2, characterized in that said tubular element is constituted by a cylindrical sleeve (38) which is also equipped with fixtures (45, 46, 47, 48) to allow to handle the ends of the threads.
A device according to claim 3, characterized in that it is externally equipped with at least one means (38, 39, 41a, 42a, 41b, 42b, 47, 48) for guiding, redirecting, locking at least one thread (14) which unwinds from a spool (12, 12a, 12b) during the transfer of said thread from said spool to said sleeve (38) and at the exit thereof.
A device according to claim 3, characterized in that said sleeve (38) is externally equipped with at least one means (41a, 42a, 41b, 42b, 45, 46) for redirecting the path of the trailing end of the thread (43a, 43b) of at least one spool (12, 12a, 12b).
A device according to claim 3, characterized in that said sleeve (38) is externally equipped with at least one means for locking (47, 48) the trailing end (44b) of the thread (44a) of the spool (12, 12a, 12b) ) proximate to the leading part of the thread of a second spool (12b) so as to subsequently tie said leading part to said trailing end (44a).
A device according to claim 3, characterized in that said sleeve (38) is externally provided with at least one means (49) for locking the trailing end (44b) of the thread of the spool (12b) which is standing by to be used.
A device according to claim 3, characterized in that if two spools (12a, 12b) are used to ensure uninterrupted feeding of at least one thread to the weaving machine, the sleeve (38) is fixed to a base (36) for supporting the two spools which advantageously passes in the central region of said base.
A device according to claim 8, characterized in that it comprises means for ensuring uninterrupted feeding of the at least one thread, which are constituted by two arms (39, 40) opposite to each other and protruding laterally from said sleeve (38), each arm being provided with an eyelet (41, 42) for guiding said at least one thread.
A device according to claim 5, characterized in that the means for redirecting the path of the thread trailing end of the second spool (44b, 43b) are constituted by two curved prongs (45, 46).
A device according to claim 6, characterized in that the means for anchoring the trailing end (43b) of the thread of the spool (12a) proximate to the leading part (44a) of the thread of the second spool (12b) so as to form the knot (50) are further provided which are constituted by an elastic flap (51).
A device according to one or more of the preceding claims, characterized in that at least one means (31) for tensioning the thread passing through the sleeve (2, 38) is arranged proximate to the outlet of said sleeve.
A device according to one of claim 3, characterized in that a rod (26) is associated with the sleeve (2, 38) and is provided with at least one hook (25) for guiding the insertion and extension of the thread (14, 43a, 44a) inside said sleeve.