EP1932793B1

EP1932793B1 - Device and process for preparing bobbins to feed to an automatic winder

Info

Publication number: EP1932793B1
Application number: EP20070122361
Authority: EP
Inventors: Roberto Badiali; Giorgio Colomberotto; Luca Guarda; Luciano Bertoli; Sergio Zanini; Mauro Gobbato; Roberto Zoccarato
Original assignee: Savio Macchine Tessili SpA
Current assignee: Savio Macchine Tessili SpA
Priority date: 2006-12-13
Filing date: 2007-12-05
Publication date: 2011-07-27
Anticipated expiration: 2027-12-05
Also published as: EP1932793A3; EP1932793A2

Description

The present invention refers to a device and process for preparing bobbins to feed to the automatic winder.
In industrial practice, the prevailing yarn production technique consists of in a first spinning stage - typically ring spinning which produces bobbin yarn - followed by a second winding stage in which the yarn is unwound from its bobbin, cleaned of its defects and rewound onto a package, which contains a much greater yarn quantity and which corresponds to a considerable number of processed bobbins. The winding processing is much faster than the spinning and thus a small quantity of winding units or stations, approximately several dozen, is capable of completing the production of a great number of yarn units, on the order of several thousands. The transfer between the two processing sessions, of the bobbins full of yarn to the winder and their empty tubes to the spinning machine, can occur "en masse" or by means of movable bins, or - in the so-called "spin-winders" - directly and individually transferring the bobbins to the winder. Generally, the bobbins arriving from the spinning machine have the terminal part of their yarn wound a specific number of turns around the bobbin pack or the base of its tube.
In the most recent automatic winders, the prevailing technique of moving the bobbins and tubes is that which employs plate supports to be placed on conveyor belts or similar moving service members of the machine - for example rotating discs or belts - to individually bring said bobbins and tubes to and from the winding units.
Generally, said plates consist of a disc base which bears a central, vertical pin, on which the bobbin tube is inserted. This pin allows maintaining the bobbin in upright position not only during the transport but also in the preparation and winding phases, in such a manner transferring and processing the bobbins practically without touching them. In fact only the plates are handled, without the bobbins being touched and scraped against, becoming dirtied or damaged in contact with the machine.
The present invention is aimed for the preparation of the bobbin, maintaining it upright on its plate. Before being fed to one of the winding stations which make up the automatic winder, the bobbin to be wound must be prepared, with a processing which is carried out in several steps. The terminal part of the yarn on the bobbin must be freed from the base of the tube, or from the body of the bobbin, and unwound from the outer surface of the bobbin for a certain length. The yarn is then cut to size and inserted in the upper end of its tube, from which the winding station - at the beginning of the winding of the new fed bobbin - can draw it, splice it with the skein end available on the package and restart the winding. Such preparation is required both for the new bobbins coming from the spinning machine and for the not completely wound bobbins which - in the automatic winder - are generally recovered and recycled in order to use up the residual yarn still wound thereon.
As regards the preparation of the bobbins by finding the end of the yarn to be unwound DE 4434304 discloses to control the air current flowing along the surface of the bobbin by a hollow tube surrounding the bobbin and movable up and down with respect to a yarn finding position. DE 4025003 discloses a yarn end catching device consisting of a sucking slot vertically movable up and down along the spool to be prepared.
DE 4424462 discloses devices for guiding and retaining the yarn end in its prepositioning in the upper part of the cop to be unwound. The yarn is cut, wound on the nose of the cop, and then unwound and inserted into the tubular interior of the cop. DE 3444821 discloses devices for the recovery of the reserve turns of the yarn wound on the tip of the cop by a pair of clamping jaws that can lowered and lifted by telescopic means. The so recovered yarn end is cut and inserted into the cop, determining its length by a pair of swinging rods that deviate the captured end of the yarn from the vertical direction before its cutting and suction into the cop sleeve.
US 4,595,152 discloses a pick finding process in which the end of the yarn is detached by a vertically movable brush, cut and simultaneously inserted by suction into the central hole of the cop. US 4,619,416 discloses to release the end of the yarn from the bobbin by a vertical air current flowing along the surface of the bobbin within a hollow tube surrounding the bobbin and movable up and down with respect to a yarn finding position. The yarn is then clamped and cut at a predetermined distance from the clamping device. A reverse flow of air directs the remaining length of yarn into the hollow bobbin core.
The invention is described here with reference to a typical embodiment thereof in an automatic winder. Generally, such winder type is composed of a plurality of winding stations or units aligned along the front of the machine and equipped with common service equipment for their management, among which the bobbin preparation unit is also comprised. In the prior art, the sequence of the bobbin preparation operations is generally carried out with separated members and/or by transferring the bobbin to be prepared from one member to the other, with a complex procedure and with costly and bulky devices.
The present invention, in its most general definition as bobbin preparation device, is defined in the first claim. Its preferred variants or embodiments are defined in the dependent claims 2-14.
The present invention, in its definition as bobbin preparation process before its winding in a winding station, is defined in claim 15. Its preferred variants or embodiments are defined in the dependent claims 16-27.
The characteristics and advantages of the bobbin preparation device and process according to the present invention will be clearer from the description of a typical exemplifying and non-limiting embodiment thereof, illustrated in figure 1.
In figures 2 - 5, an embodiment variant of the invention is illustrated, of which:

Figure 2 shows the plate with its bobbin to be prepared, in order to illustrate the further technical problem confronted with such embodiment variant,
Figure 3 shows an embodiment of the invention with pressing spindle,
Figure 4 shows an embodiment with skein end finder brush,
Figures 5 A-I show the bobbin preparation process steps with the spindle of figure 3.

In the exemplifying embodiment shown in figure 1, the following components are found with the related numeric references:

1) Bobbin to prepare on its plate and spaced with the
1A) Stop, in order to retain it while waiting in position A,
2) Bobbin on its plate in the preparation position P,
3) Motorised roller for rotating the bobbin 2,
3A) Idle rollers for positioning the bobbin being processed,
4) Centring spindle of the bobbin 2,
4A) Approaching/distancing control of the spindle 4,
5) Suction mouth which, in its generatrix line closest to the bobbin (preferably concave progression as in the detail to the left), is equipped with a
5A) Slit which is extended from its base over its entire concave generatrix line, up to its curved top which joins it with the shutter.
6) Skein end finder element of mechanical type for separating the skein end of the yarn from its winding on the bobbin 2, which in the embodiment of figure 1 is composed of a skein end finder hook 6, while in the embodiment of figure 4 it is composed of a brush element 50. In figure 1, such hook-shaped element is actuated by an
6A) Actuation device of the hook-shaped element 6 which brings such element 6 closer to and away from the generatrix line of the bobbin and makes it slide from the top towards the bottom and vice versa in order to remove the skein end from the rotating bobbin. In figure 4, such actuating device for drawing in the brush element 50 has the reference number 50A.
7) Presence sensor of the yarn picked up by the mouth 5.
8) Shutter of the suction air of the mouth 5, shown in detail with regard to the "open" and "shut" positions.
9) Presence sensor of the yarn in the scissors 15.
10) Suction mouth under the bobbin 2 being processed.
11) Conveyor belt, always in motion.
12) One or more Venturi nozzles for the insertion of the skein end in the bobbin.
13) Photocell sensor of the presence of the awaited plate with bobbin.
14) Photocell sensor of the presence of the plate with bobbin being processed.
15) Scissors, shown open in the enlarged detail on the left, and with
15A) Movable cutter in intermediate position.
16) Bobbin yarn.
17) Plate, preferably (see figure 2) equipped with through holes 20 from its lower abutment face to the top of its upper pin 21.
18) Stop of the plate for stopping and maintaining the bobbin being processed in the preparation position P.
19) Bobbin fastening.

The preparation cycle is carried out, for example, as follows. The system is provided - for example - to always keep the processing position occupied with a bobbin ready for preparation or being prepared, and the waiting position always occupied by a bobbin to be prepared. The cycle execution is governed by a governing unit (not indicated in the figures for the sake of simplicity) dedicated to the preparer device which receives the signals from the sensors present in the various parts composing the device and sequentially sends the commands for carrying out the various operations of the cycle.

Step A): When the winder draws the bobbin 2 prepared on its plate, the work position is freed of such plate, by opening the stop 18 and allowing the plate to be carried away by the conveyor belt 11. In the absence of a bobbin, the photocell 14 is thus deactivated, signalling that a new bobbin to be prepared must be drawn into such position. The stop 18 is re-closed in order to stop the new bobbin arriving for processing.
Step B): There is a bobbin in the waiting position, and the photocell 13 is then activated; the stop 1A is removed and the conveyor belt 11 brings the plate with its bobbin into work position, substituting the prepared and unloaded bobbin.
Step C): The waiting position is now free, the photocell 13 is deactivated, and the governing unit requests a new plate with the bobbin to be prepared and closes the stop 1A: the conveyor 11 brings the new bobbin, which activates the photocell 13 and is ready for the next step B.
Step D): Upon the arrival of the new bobbin 2 to be prepared into the work position, and once locked against the stop 18, the photocell 14 is activated and the idle centring rollers 3A are controlled to abut against the plate 17, pushing it against the motorised roller 3, which serves to drive the bobbin being prepared into rotation.
Step E): The control 4a brings the spindle 4 close to the top of the bobbin, so to centre the bobbin 2 in vertical position.
Step F): The shutter 8 is opened to the maximum flow rate of the mouth 5.
Step G): The roller 3 is activated, making the bobbin 2 rotate a specific number of turns in the unwinding direction of the yarn reserve placed around the bobbin or its base. Due to the strong suction inside the mouth 5, the slit 5A has a considerable suctioning effect towards the skein end of the yarn 16 of the bobbin being processed, which it draws from the bobbin itself inside the mouth 5. The signal of the sensor 7 is awaited, signalling the presence of the yarn 16, which oscillates and vibrates inside the upper part of the mouth 5.
Step H): Upon yarn detection, the shutter 8 is re-closed, maintaining the "shut" flow at a low flow rate and the rotation of the bobbin 2 is stopped; with such operation, the yarn 16 is still taut, it can exit from the slit 5A and enter the opening of the scissors 15.
Step I) : The scissors 15 are activated for cutting the yarn 16 which is brought outside the slit, optionally waiting for the presence sensor 9 of the yarn in the scissors 15 to give a positive signal of the yarn presence.
Step J): The cutting is carried out, maintaining however a strong air flow towards the interior and bottom of the bobbin tube, so to draw the skein end of the cut-to-size yarn therein by means of the suction mouth 10 placed under the bobbin 2, which draws the yarn through the holes 20 and/or the Venturi nozzle 12 placed on the spindle 4. Such Venturi nozzle is supplied with pressurised air, and draws air from the upper part of the spindle 4 towards the interior of the tube of the bobbin 2 being processed, bringing therewith the skein end of the cut-to-size yarn 16. According to a preferential embodiment of the present invention, the length of the cut skein end, to be inserted at the top of the tube, is adjusted by placing the scissors 15 on a support 15B with adjustable height with respect to the top of the tube of the bobbin being processed 2, the adjustment means of the support 15B not being indicated in the figure for the sake of simplicity.
Step K: The control 4A takes the spindle 4 away from the top of the bobbin 2 and frees the bobbin.
Step L: The idle centring rollers 3A are controlled to move away from the plate 17, freeing it.
Step M: The bobbin 2 is ready to be drawn by the winder.

When the yarn on the bobbin to be processed has a hard time being freed from the surface of the bobbin itself, whether because the yarn is "hairy" and/or because it was wound with a considerable tension, a modified cycle is preferable and more reliable. In such a cycle, with respect to the previously exemplified cycle, a step E* is inserted between step E and step F of the preceding cycle, such step E* employing the device 6A, which brings the skein end finder hook 6 against the bobbin 2. The device 6A brings the skein end finder hook 6 towards the bobbin 2, it makes it slide along the generatrix line of the bobbin itself in order to lift or remove the skein end of the fastening 19, possibly pulling it free. For such a purpose, the roller 3 for rotating the bobbin 2 being processed is equipped with actuation in the two rotation directions, clockwise and anticlockwise.
Step E* is executed as follows. A first slow, descending movement of the hook 6 drawn near is carried out, and while the bobbin 2 is made to rotate in its winding direction, the hook finds the wound yarn, which surmounts it, freeing its skein end from the body of the bobbin 2. Or, if the skein end resists since it is held at the base of the tube, the hook pulls free the yarn. There is not yet need to activate the maximum suction with the mouth 5. At the end of such descent, the governing unit of the preparer controls the separation from the bobbin 2 and the ascension of the skein end finder hook 6.
The preceding cycle is restarted with steps F-M, with the difference that, due to step E*, there is a loose spiral of the freed yarn on the generatrix line of the bobbin 2, such yarn not being constrained to the bobbin or the tube base. As said, during step F the suction with the mouth 5 is activated to the maximum level, the yarn drawn from the bobbin enters the mouth 5 and affects the yarn presence sensor 7 in the mouth itself.
The additional step E* of picking up the skein end of the bobbin 2 with the skein end finder hook 6 of figure 1 or brush element 50 of figure 4 can be carried out in a conditional or unconditional manner.
In the conditional manner, which can be programmed for all types of yarn being processed, the above-described base cycle is carried out up to the end of step G, and if at the end of said step G the sensor 7 signals the taking of the skein end with the mouth 5, the cycle continues normally and without said step E*. On the other hand, if the sensor 7 does not signal the "successful result" of the skein end being picked up only by suction, the bobbin preparation governing unit commands the interruption of the base cycle carried out up to step G, it makes it go back to step F and then commands the restarting of the cycle from step F, preceding such step however with the additional step E* for finding and separating the skein end with the mechanical hook device 6 or brush device 50.
In the unconditional mode, preferable when the yarn being processed is more "difficult", the work cycle is programmed in the governing unit with the step E* already stably inserted before step F, avoiding cycle interruption after step G and avoiding returning back, after a skein end pick-up attempt only by suction with the mouth 5.
An improved embodiment of the device according to the invention is described below with reference to figures 2-5; such device allows working with greater output and reliability.
In the prior art, which employs the plate 17 as vehicle and support of the bobbin being processed, as in the present invention, the rotation of the bobbin is carried out by also making the plate rotate with the roller 3: the plate transmits the rotary motion to the bobbin by friction. The pin 21 of the plate 17 is necessarily made with a slightly smaller diameter than the inner diameter of the tube 23 of the bobbin 2, in order to allow the easy insertion and extraction of the bobbins respectively on and from the plate 17. The transmission of the rotary motion therefore occurs by the frontal friction between the circular base rim of the tube 23 and the upper annular surface of the collar 24 of the plate 17.
In order to increase the transmittable rotary torque between these two elements 23,24, the improvement consists in the modification of the spindle centring system 4 of the bobbin 2 and its control 4A for approaching/moving away from the top of the tube 23 of the bobbin 2, as illustrated in figure 1, so to centre the bobbin 2 on the plate 17 and to press it against its collar 24 in order to increase the transmittable torque to the desired level.
As illustrated in figure 3, the centring spindle 30 of the bobbin is made with two separate and coaxial elements 31 and 41, equipped with means for approaching/moving away from the top of the tube 23 of the bobbin 2, until they are brought into abutment against the tip of the tube 23, said means also allowing reciprocal movements between such elements 31,41 in the axial direction.
The first element 31 has the form of a frustoconical funnel, with a side cleft 32 to direct towards the slit 5A in order to permit the entrance of the yarn suctioned by the mouth 5 and a narrow side opening 34, lateral and opposite to the cleft 32, in which the support arm of the second element 41 moves. Such element 41 is moved inside the cavity and funnel which composes the first element 31.
The second element 41 is composed of an idle rotating spindle 42 mounted on watertight bearings 43 and supported by a support arm 44 which is raised and lowered with means 45, for example with a pneumatic cylinder system which in turn supports the outer funnel-shaped element 31, which is shown in figures 5A, B. As shown in figure 3, the idle spindle 42 is axially perforated with a duct 46 and supplied with compressed air by means of the connector 48, in order to act as injector for the insertion of the end of the cut-to-size yarn inside the tube 23, entirely analogous to that of the previously described Venturi 12.
Both the first element 31 and the second element 41 are equipped with lifting and lowering means, analogous to those previously indicated like 4A in the exemplifying embodiment of figure 1. Such means, which in the following figures were shown as an example as a pneumatic piston 35 for the funnel-shaped element 31 and a pneumatic piston 45 for the idle spindle element 41.
In order to obtain the desired torque transmission between the plate and tube, the governing unit of the winder preparation station can be prearranged to adjust the supply pressure of the compressed air to such pneumatic pistons as a function of the processing work to be completed.
The spindle 30 thus formed by the two parts 31 and 41 accomplishes the functions of:

centring the upper part of the tube 23,
pressing the tube 23 against the plate 17,
seizing the yarn prepared between the top of the tube and the spindle 30,
inserting the prepared skein end in the tube.

In figure 4, an embodiment of the device according to the invention is illustrated in which the skein end finder element is achieved with a brush 50 which is supported by a device 50A which supports the brush with an arm 51 capable of moving parallel to the axis of the bobbin 2, elastically pressing the skein end finder brush 50 against the bobbin 2. In order to pick up the skein end from the bobbin, the device 50A extends the arm 51 and brings the brush 50 against the bobbin, making it slide along the generatrix line of the bobbin itself in order to lift the skein end of the fastening 19. During the movement of the brush-like skein end finder element 50 against the bobbin, the roller 3 is actuated in the bobbin unwinding direction.
The elastic support of the brush 50 by the arm 51 permits the brush itself to be moved along the line 52, consistent with the profile of the bobbin generatrix line, also faithfully following the terminal frustoconical parts. The brush 50 can be made with normal natural or synthetic bristles, with small, thin cylinders of natural or synthetic rubber.
The processing steps and movements of the spindle 30 describe above with reference to figures 3,4 are described below with reference to figures 5A-5I.
In figure 5A, the bobbin 2 is shown in a preparation position with the spindle 30 still raised. In figure 5B, the extension of the piston 35 is shown with the descent of the funnel-shaped element 31 against the tip of the tube 23, in order to centre it and push the tube against the collar 24 of the plate. The second spindle element 41 remains raised.
In figure 5C, the retraction of the piston 45 is shown along with the descent of the spindle 41 with the partial insertion of its conical end in the tip of the tube 23. Due to the pressure exerted by the piston 45, the tube is pushed against the plate, in order to ensure that the rotation impressed on the plate is transmitted by frontal friction also to the bobbin 2. There follows the lifting of the funnel-shaped element 31, retracting the piston 35 and leaving only the spindle 41 to act as centring and thrust member.
In the position shown in figure 5C, the bobbin preparation steps E-H are carried out as described above, and in particular the rotation of the bobbin, with the possible step E* for removing the skein end by means of the skein end finder hook 6 of figure 1 or the skein end finder brush 50 of figure 4, suctioning the skein end into the mouth 5, inserting the skein end of the yarn 16 into the scissors 15 and into the cleft 32 of the funnel-shaped element 31, as shown in the configuration of figure 3 and 5D.
As shown in figure 5E, the spindle 41 is raised by driving the piston 45 upward. As shown in figure 5F, the piston 35 is extended and the funnel-shaped element 31 of the spindle 30 lowered so to seize the skein end of the yarn 16 between the lower frustoconical face 36 of the funnel 31 and the tip of the tube 23. Figure 5G shows the cutting of the yarn 16 with the scissors and figure 5H shows the effect of the air blowing through the axial duct 46 in the spindle 42 of the element 41. The cut skein end is inserted in the cavity of the tube 23: the quantity of yarn inserted in the tube is controlled, since the additional yarn winding by the bobbin is blocked by the engagement of the skein end between the funnel 31 and the tip of the tube 23. Figure 5I shows the final lifting of the funnel element 31 for the release of the bobbin 2 prepared for winding processing.
When working with yarns that are very resistant to unwinding, which require the transmission of even higher torques, a further improvement of the present invention provides for increasing the friction between the surface of the upper rim of the collar 24 of the plate 17 and the bottom of the tube 23 of the bobbin 2. Such friction increase is obtained as shown in figure 2, by interposing an annular insert 60, for example fixing it on the collar 24, such insert 60 made of a material which offers a high friction coefficient, for example soft rubber. Alternatively, in order to increase the grip between the two surfaces in contact - the upper rim of the collar 24 and the bottom of the tube 23 - one or both of such surfaces can be processed to make them rougher, or separately-prepared rough inserts 60 can be attached thereto.
In comparison with the bobbin preparation systems in the prior art, the package bobbin preparation process and device of the present invention offers considerable advantages. Several of these benefits are worth a brief mention below.
With respect to the currently used technical solutions which divide the operations between several work stations, all of the preparation operations are carried out with the bobbin in the same position, with savings of the transfer spaces from one station to another, and avoiding any duplication of the members which make up such stations. The execution of the bobbin preparation cycle is carried out with a sequence of steps, in which subsequent steps are each carried out upon the reception of the "successful result" signal of the preceding step. The governing unit of the preparation device allows adapting the cycle and its operations to the production needs. Any step which does not have a good end result can be repeated a predetermined number of times, even varying its parameters, in order to achieve a flexible preparation cycle of the bobbin.
The bobbin preparation device according to the present invention moreover allows adapting the preparation operations as a function of the bobbins to be worked, for example according to the type and count of the yarn, as well as the manner of its winding on bobbins in the preceding spinning, stably or conditionally inserting the supplementary step E* for finding the skein end and separating it from the mechanical hook or brush skein end finder element, adapting the reduced suction pressure value of the mouth 5, the rotation speed of the bobbin 2 - both in winding and in unwinding - with the roller 3, as well as the transmittable torque with said roller, the modality of drawing near and moving the skein end finder element, whether hook 6 or brush 50, the length of the skein end inserted inside the tube 23, and so on.

Claims

Device for preparing bobbins fed to an automatic winder, which comprises means for freeing the skein end of the yarn reserve wound on the bobbin (2), which is borne by a plate carrier (17) thereof, means for its suction inside a mouth (5), means for positioning the yarn (16) thus picked up in a scissors (15), means for cutting the yarn (16) to size in the scissors (15), and means for inserting the skein end of the bobbin thus cut from above and into the tube (23) of the bobbin (2), said processing means being all grouped together in a single work station (P) and coordinated in their operations sequence by a governing unit dedicated to the bobbins (2) preparation device,
characterised in that the preparation means of the bobbin comprise means for increasing the rotary torque transmittable between the tube (23) of the bobbin (2) and the collar (24) of the plate (17) which transports the bobbin (2), and in that said means for increasing the rotary torque comprise a bobbin centring spindle (30) which is made with two separate and coaxial elements (31) and (41), equipped with means (35,45) for their approaching/moving away from the top of the tube (23) of the bobbin (2), as well as reciprocal and axial movement with respect to each other, said elements (31, 41) being able to be brought into abutment against the tip of the tube (23), and in that the spindle (30) is formed with a first element (31) of frustoconical funnel form and a second element (41) which is moved inside the funnel-shaped cavity of the first element (31) and comprises an idle rotating spindle (42).
Device for preparing bobbins according to claim 1, characterised in that the means for increasing the rotary torque transmittable between bobbin and plate consist of placing an annular insert (60) made of a material which has a high friction coefficient, interposed between the surface of the upper rim of the collar (24) of the plate (17) and the bottom of the tube (23) of the bobbin (2).
Device for preparing bobbins according to claim 1, characterised in that the means for increasing the rotary torque transmittable between bobbin and plate consist of processing the surfaces of the upper rim of the collar (24) and/or bottom of the tube (23) in order to make them rougher.
Device for preparing bobbins according to claim 3, characterised in that the means for increasing the rotary torque transmittable between bobbin and plate consist of attaching rough inserts (60) to the surfaces of the upper rim of the collar (24) and/or bottom of the tube (23).
Device for preparing bobbins according to claim 1, characterised in that the means for freeing the skein end of the yarn reserve wound on the bobbin (2) comprise a motorised roller (3) for rotating the bobbin (2) in its winding and unwinding direction, a suctioning mouth (5) equipped with a slit (5A) which extends from its base over its entire concave generatrix line up to its top, as well as a skein end finder element (6, 50) of mechanical type for separating the skein end of the yarn from its winding on the bobbin (2), actuated by means (6A,50A) capable of bringing it close to and away from the bobbin generatrix line, and to make it slide up and down, so to remove the skein end from the bobbin (2) placed in rotation.
Device for preparing bobbins according to claim 1, characterised in that the mouth (5) is equipped with a concave sector which borders the generatrix line of the bobbin (2) being processed and which bears the slit (5A) in the centre line of its recess.
Device for preparing bobbins according to claim 1, characterised in that the means for suctioning the skein end of the yarn inside a mouth (5) comprise a shutter (8) of the suction air of the mouth (5), capable of two positions, "open" at maximum flow rate and "shut" at low flow rate.
Device for preparing bobbins according to claim 1, characterised in that the means for cutting to size the end skein of the yarn (16) in the scissors (15) comprise, in addition to said scissors, also adjustment means of the support level (15B) of the scissors (15) with respect to the top of the bobbin tube (2) being processed.
Device for preparing bobbins according to claim 1, characterised in that the means for inserting the skein end of the bobbin thus cut comprise a suction mouth (10) placed below the bobbin (2) being processed.
Device for preparing bobbins according to claim 1, characterised in that the means for inserting the skein end of the bobbin thus cut comprise a Venturi 5 nozzle (12) placed on a spindle (4).
Device for preparing bobbins according to claim 1, characterised in that the funnel-shaped first element (31) has a side cleft (32) corresponding with the slit (5A).
Device for preparing bobbins according to claim 1, characterised in that the idle spindle (42) of the second element (41) is axially perforated with a duct (46) and supplied with compressed air, serving as means for inserting the cut-to-size skein end of the bobbin.
Device for preparing bobbins according to claim 1, characterised in that the spindle (12) comprises pneumatic piston (35) lifting and lowering means for the funnel-shaped element (31) and pneumatic piston means (45) for the idle spindle element (41).
Device for preparing bobbins according to claim 13, characterised in that the pneumatic piston means (45) in turn support the external funnel-shaped element (31) with the related lifting/lowering means (35).
Process for preparing bobbins fed to an automatic winder which comprises the operations of freeing the skein end of the yarn reserve wound at the base of the bobbin (2), suctioning such skein end inside a mouth (5), positioning the yarn (16) thus picked up in a scissors (15), cutting the yarn (16) to size in the scissors (15), and inserting the skein end of the bobbin thus cut from above and into the tube of the bobbin (2), said operations being carried out in sequence, without moving the bobbin (2), and in a single work station (P), such sequence of operations being coordinated by a governing unit dedicated to the bobbin (2) preparation device, characterised in that the operations of freeing and preparing the skein end from the bobbin (2) being processed, in which the bobbin is placed in rotation, are carried out by holding said bobbin pressed against the plate (17) which supports it by means of a centring spindle (30), of which an element (41) with idle spindle (42) is lowered to press against the tip of the tube (23) of the bobbin (2), and in that the cutting to size of the skein end of the yarn (16) is carried out with the funnel-shaped element (31) of the spindle (30) which is lowered so to seize the skein end of the yarn (16) between it and the tip of the tube (23).
Process for preparing bobbins according to claim 15, characterised in that before proceeding with 5 picking up the skein ;end from the bobbin (2) by suctioning, there is a supplementary step (E*) for finding and separating the skein end with the mechanical skein end finder device (6,50).
Process for preparing bobbins according to claim 16, characterised in that the insertion of step (E*) is dependant on the failure to pick up the bobbin (2) skein end by suctioning only.
Process for preparing bobbins according to claim 16, characterised in that the insertion of step (E*) is unconditional, the work cycle being already programmed with the step (E*) stably inserted before proceeding with the skein end pick-up by suctioning.
Process for preparing bobbins according to claim 16, characterised in that the freeing of the skein end of the yarn reserve wound at the base of the bobbin (2) is carried out by alternately rotating the bobbin (2) in its winding and unwinding direction, suctioning its end with a suctioning mouth (5) equipped with a slit (5A) which is extended from its base up to its top, and searching for the yarn of the fastening (19) with a skein end finder hook (6), brought close to the bobbin and made to slide up and down in order to detach the yarn from the rotating bobbin (2).
Process for preparing bobbins according to claim 16, characterised in that the freeing of the skein end of the yarn reserve wound at the base of the bobbin (2) is carried out by rotating the bobbin (2) in its unwinding direction, suctioning the end with a suctioning mouth (5) equipped with a slit (5A) which is extended from its base up to its top, and searching for the yarn of the fastening (19) with a skein end finder brush (50), brought close to the bobbin and made to slide up and down in order to detach the yarn from the rotating bobbin (2).
Process for preparing bobbins according to claim 15, characterised in that the suction inside a mouth (5) of the yarn from the bobbin (2) being processed is carried out by alternating the flow of the mouth (5) suction air between a period of maximum flow rate and one of low flow rate.
Process for preparing bobbins according to claim 15, characterised in that the cutting to size of the skein end of the yarn (16) in the scissors (15) also comprises the adjusting the support (15B) level of the scissors (15) with respect to the top of the tube of the bobbin (2) being processed.
Process for preparing bobbins according to claim 15, characterised in that the insertion of the skein end of the bobbin thus cut is carried out by means of a suction mouth (10) placed under the bobbin (2) being processed.
Process for preparing bobbins according to claim 15, characterised in that the insertion of the skein end of the bobbin thus cut is carried out with a Venturi nozzle (12) placed on the spindle (4).
Process for preparing bobbins according to claim 15, characterised in that the insertion of the skein end of the bobbin thus cut is carried out by means of an air blow supplied by means of the axial duct (46) in the spindle (42).
Process for preparing bobbins according to claim 15, characterised in that the preparation operations are modified as a function of the bobbins to be processed, adopting the reduced suction pressure value of the mouth (5), the rotation speed of the bobbin (2) with the roller (3), the torque transmittable with said roller, the modality of drawing near and moving the skein end finder element, hook (6) or brush (50), the length of the skein end inserted inside the tube (23).
Process for preparing bobbins according to claim 15, characterised in that the cycle of the preparation operations is adapted to production needs, wherein every step which does not have a successful result is repeated a predetermined number of times, even varying its parameters, in order to achieve a flexible' bobbin preparation cycle.