GB2069548A - Thread Guidance System for Winding Machines - Google Patents

Abstract

A thread guidance system for a winding machine for producing parallel-wound bobbins includes thread guides (15) which press against the surface of wound packages on bobbin sleeves (11) with a pressure derived from piston/cylinder drive units (29) jointly connected to a source (35) of compressed air which is maintained at constant pressure by a valve (37) and a pressure equalisation chamber (59). The thread guides (15) can be lifted off the fully wound packages by the action of a pneumatic cylinder (34) which actuates lift arms (33). The traverse movements of the thread guides (15) are effected by reciprocating a common traverse frame (26) driven by a reversible roller ring transmission (41). <IMAGE>

Description

SPECIFICATION Thread Guidance System for Winding Machines This invention relates to a thread guidance system for winding machines for producing parallel-wound bobbins, the system comprising a thread guide arranged to make pressure contact with the peripheral surface of a package as it is wound on a bobbin sleeve, and a thread guide carrier relative to which the thread guide is movable and which is driven in reciprocatory manner parallel to the longitudinal axis of the bobbin sleeve.

In one known thread guidance system of this type, as described in West German published patent application 1 5 60 499, cross-wound or parallel-wound bobbins are produced. Sloping ends are formed on the wound packages as the' thread guide has to perform an axial displacement in its thread-laying traverse stroke in dependence on the increasing package diameter. This is achieved by virtue of the fact that the thread guide slides on guides which are set at an angle corresponding to the angle of slope of the wound package, and the contact of the thread guide against the peripheral surface of the wound package is effected by spring force. However, this known thread guidance system is not suitable for producing parallel-wound bobbins with precision and particularly is not suitable for winding speeds up to 10,000 rpm.This is because, among other things, the thread guide cannot be held precisely enough on the peripheral surface of the package by its thread guide carrier. There are many factors which play a role in this. In particular, the spring which is used does not enable a constant pressure to be exerted as the package diameter increases. Particularly with the bobbins with inclined flanges at the ends of the sleeve the contact force of the thread guide depends upon the angle of inclination of the flanges since the springs acting on the thread guides are compressed to a greater or lesser extent depending upon their sloping disposition.

Moreover, a spring does not have the ability to hold the thread guide in contact with the peripheral surface of the package without flutter when the spring produces vibrations at high winding speeds, since the spring lacks any damping.

In contrast to this, it is an object of the present invention to provide a thread guidance system of the type first mentioned above which is suitable for producing high-precision parallel-wound packages on bobbin sleeves with inclined flanges, i.e. so-called diabolo sleeves, at high winding speeds.

This is achieved in accordance with the present invention by such a system in which the pressure with which the thread guide contacts the package is derived from piston/cylinder drive means connected to a source of compressed air supplying compressed air at constant pressure, the piston/cylinder drive means also being in communication with pressure equalisation means which is operative in the event of an increase in pressure as a result of the thread guide moving away from the bobbin sleeve as the diameter of the wound package increases.

It is of importance that the thread guide is pneumatically powered so that even at high winding speeds it rests in contact with the peripheral surface of the package without flutter.

It is also important that the pressure can always be maintained exactly the same independently of the package diameter. The thread guidance system of the present invention makes it possible to retain the principle of enabling the thread guide to back off from the bobbin sleeve with increasing circumference of the package being wound, which is important on account of the tolerances in the thread to be wound.

It is true that it is known in a machine for producing high-precision parallel-wound bobbins at high winding speeds to provide for the thread guide to contact the peripheral surface of the wound package with an adjustable pressure in order thus to influence the wound structure by the effect of the pressure. However, in this arrangement the thread guide is lifted at each end of a traverse stroke and of a wound layer by a complex device, the lifting being through a distance corresponding to the thread diameter.

However, since this includes tolerances, it results in inaccuracies in the wound structure. Also, with this well known machine, the thread guide is powered by a spring and at high winding speeds does not contact the peripheral surface of the package with freedom from flutter.

In a thread guidance system with a plurality of winding heads at each of which there is a thread guide it is advantageous if each thread guide is provided with its own exclusive piston/cylinder drive means, and if the piston/cylinder drive means of all the winding heads are connected in common to the same source of compressed air.

By individually driving each thread guide, each winding head is independent of the occurrences at another winding head, for example in relation to the adjustment. The common powering of all the piston/cylinder drive means from one and the same compressed air source ensures comparatively the same behaviour of all the thread guides, e.g. with regard to the uniformity of the contact pressure of the thread guides against the peripheral surface of the packages.The pressure equalising means, a chamber in a preferred embodiment of the invention, is preferably connected into a connecting pipe provided between the compressed air source and the piston/cylinder drive means and has a volume which is large in relation to the connecting pipe, so that any pressure increase arising as a result of the backing off movement of the thread guide as a result of increasing package diameter can be better controlled.

Preferably, the or each thread guide is powered not only by the piston/cylinder drive means but also by a compressed air cylinder which provides for the lifting of the thread guide away from the peripheral surface of the package. This is arranged to be actuated only when the piston/cylinder drive means is switched off. With the help of the compressed air cylinder the thread guide can be moved sufficiently far from the surface of the package that it is possible to exchange the bobbin. In addition, this means that several processes relevant to the setting up or the raising of the thread guide can be accomplished under compressed air actuation.

All the reciprocatingly driven thread guide carriers and the piston-cylinder drive means are preferably secured jointly to a traverse frame.

Movement of this frame is powered by a roller ring transmission which is reversible to two end stops. This provides the necessary precise movement of the thread guide relative to the bobbin which, particularly at the reversal points, ensures an immediate delay-free reversal of the direction of traversing movement. The end stops are preferably movable to different positions each corresponding to the angle of inclination of the end flanges of the bobbin sleeve, so that as a result of this one can even wind sleeves whose end flanges have angles of inclination which differ from one another. The flatter the angle of inclination the easier it is to effect overhead withdrawal of the thread from the bobbin when the bobbin is suspended overhead.

In order that the invention may be fully understood a preferred embodiment of thread guidance apparatus in accordance with the invention will now be described by way of example and with reference to the accompanying drawings, in which: Fig. 1 is a schematic perspective view of the thread guidance system; and, Fig. 2 shows the mechanical construction of that part of the system which is in the region of the thread guides.

The winding machine shown in the drawings has four winding heads 10 at which bobbin sleeves 11 are positioned each of the sleeves 11 being provided with end flanges 12 having sloping inner faces 13 so as to form a so-called diabolo bobbin. A thread 14 which is drawn from a feed supply bobbin (not shown) is wound on each of these bobbin sleeves with the aid of a thread guide 15. The driving of the bobbin sleeves 11 is effected by way of winding spindles 1 6 which are driven either directly or by way of toothed belts 19 from a drive shaft 18. The drive shaft 1 8 is itself driven by an infinitely variable speed transmission 20 which is powered by a main drive motor 21.

As is shown in Fig. 2, each thread guide 1 5 is secured to a pivotable lever 22 by a screw fastening. Consequently, it can easily be exchanged for a different thread guide, as is necessary if the gauge of the thread 14 which is being wound is altered. The contact surface 23 of the thread guide 1 5 which contacts the wound package is provided, as shown in Fig. 1, with thread guidance and/or pressing grooves 24 running in the direction of travel of the thread.

These grooves 24 press against the on-running thread 14 and smooth out the turns of the wound package which have been wound on shortly before and which are immediately adjacent to the current on-running position of the thread. If the grooves, which are matched in size to the dimensions of the thread, have a slightly smaller spacing from each other than the diameter of the thread, then the grooves exert pressure on the thread turns in the direction of the bobbin sleeve axis. In this way the appearance of the wound bobbin can be favourably influenced with allowance for variations in the thread.

Each pivotable lever 22 is mounted for pivotal movement on an arm 25 of a traverse frame 26.

Moreover, adjacent to this bearing position of the pivotable lever 22, there is clamped a thread guide carrier 27 which is attached to a crosspiece 28 which carries a piston/cylinder drive unit 29 for the respective thread guide 1 5. A piston rod 30 of the piston/cylinder drive unit 29 is connected to the pivotable lever 22 by way of a shackle joint 31 so that longitudinal displacements of the piston rod 30 produce corresponding pivotal movements of the lever 22.

Each pivotable lever 22 has an angle arm 32 which can be rotated in the clockwise direction by a lifting rod 33 actuated from a compressed air cylinder 34, so that the thread guide 1 5 thereby executes a corresponding movement. The compressed air cylinder 34 is able to drive the respective lifting rods 33 of all the thread guides 1 5 from a piston rod 34'. By raising the thread guide 1 5 from the fully wound bobbin it is then possible to exchange bobbins.

The piston/cylinder drive units 29 and the compressed air cylinder 34 are connected to a compressed air supply 35. A pressure regulating valve 37 which can be adjustably set by means of a handle 36 ensures that the pressure at the output side of the valve is kept constant. A pressure indicating instrument 38 provides for the visual setting and supervision of the desired pressure at the output side of the valve. A connecting pipe 39 is connected to the output of the pressure regulating valve 37 and is connected' to a pressure chamber (not shown) of each of the piston/cylinder drive units 29. Moreover, a feed pipe 40 for the compressed air cylinder 34 is also connected to the compressed air supply 35 and to the pressure regulating valve 37. The connection is so arranged that the compressed air cylinder 34 only receives compressed air from the remotely controllable pressure regulating valve 37 if the piston/cylinder drive units 29 are pressureless, so that one does not have the two drive systems acting on the pivotable levers 22 in opposing senses.

In the connecting pipe 39 there is fitted a pressure equalising chamber 59 whose volume is determined in relationship to the volume of the connecting pipe 39 and the volume of the pressure chambers of the piston/cylinder drive units 29. Thus, the volume of the pressure equalising chamber 59 is chosen to be so large that the backing-off movement of the thread guides 1 5 with increasing size of the wound bobbin packages does not lead to any noticeable increase in the contact pressure of the thread guides 15 against the periphery of the wound packages. If the pressure chambers of the piston/cylinder drive units 29 together with the connecting pipe 39 have a sufficiently large volume, then this may make it unnecessary to fit a special pressure equalising chamber in the connecting pipe 39.

The thread guides 1 5 are secured, together with their respective piston/cylinder drive units 29 by way of the thread guide carriers 28, to the arms 25 of the traverse frame 26, so that they can be driven in a reciprocating manner in unison and thus traverse the bobbin sleeves as the thread is wound. The drive motion is effected by means of a roller ring transmission 41 which converts the rotary movement of a friction shaft 42 into a reciproating movement of the traverse frame 26.

The friction shaft 42 is for its part driven from the main drive motor 21 by way of the variable speed transmission 20 and appropriate drive belts 43.

In such roller ring transmission the roller rings each consist of an outer ring and an inner ring which are supported spaced from one another by means of roller bearings. The inner rings are brought into force-transmitting engagement with the outer surface of the friction shaft 42. In Fig. 1, three such roller rings are shown provided in a common housing with each ring having an angular setting which is at an angle to the plane perpendicular to the axis of the friction shaft 42.

The angular setting of the central roller ring is reversible so that the transmission 41 moves either to the right or to the left along the shaft 42.

The roller ring transmission 41 has a reversing lever 44 for reversing the roller ring 41', the lever causing the reversal when it strikes against respective end stops 45 and 46, so that there is an immediate reversal of the movement of the roller ring transmission 41 which leads to a correspondingly prompt reversal of the traversing movement of the thread guides 15. This is of particular significant at high winding speeds in order to achieve an accurately wound end product.

The end stops 45, 46 are mounted on respective adjustable spindles 47 which are threaded over part of their length, the stops being secured against rotation with the spindles, so that rotation of the spindles 47 by one or two setting drives 48 leads to horizontal displacement of the end stops 45, 46. The setting drive 48 includes a drive motor 49 which effects the driving of the spindles 47 by way of a worm gear 50, an electric clutch 51, an electric brake 52 and a drive belt 53. A perforated disc 54 is provided within this drive system so that the end stops 45, 46 can be accurately positioned. By photoeiectric sensing of holes 55 in the perforated disc 54 by means of photoelectric cells 56, count pulses are fed to a counting device which initiates corresponding switching commands.For example, the magnetic clutch is actuated for sufficiently long until the counting device reaches a predetermined count of light pulses which corresponds to a particular setting of the end stop 45. During this time the electric brake 52 is freed, but the brake is applied immediately the desired position of the end stop 45 has been achieved in order to avoid errors in positioning as a result of inertia of the components. The positioning of the end stops 45 and 46 during the course of a winding operation is carried out by using the outer ring of holes 55 in the perforated disc 54, so that the thread guides are moved outwardly in stepwise manner in their traverses, in matched relationship with the angle of inclination defined by the end flanges of the diabolo-shaped bobbins.Two inner holes in the perforated disc 54, only one of which is visible in Fig. 1, enable one to move the thread guides into their initial settings. In order to monitor the actual position of the end stop 46 there is mounted on the end stop a signal transmitter for the traverse changes, while on the traverse frame 26 there is mounted another signal transmitter, as a result of which the thread guides can be moved into their initial positions. The roller ring transmission 41 includes a positional counter. The initiation of the application of the rotary force from one of the setting drives 48 to one of the setting spindles 47, or by way of an intermediate shaft to both setting spindles with a common setting drive, is effected by way of a further electric clutch 58 or by way of a disengageable intermediate shaft which causes an increase or a reduction in speed as required, as a result of which the rotation of the perforated disc 54 can take place without adjustment movement of the setting spindles 47, or a manual adjustment of the end stops 45, 46 is possible by turning the spindles through knobs 57 provided at their ends. With the manual adjustment the end stops 45, 46 can be set to the minimum spacing which corresponds to the basic traverse stroke which the thread guides 1 5 have to make in order to wind the cylindrical portion of the bobbin sleeve.

Claims (1)

1. Claims

   1. A thread guidance system for a winding machine for producing parallel-wound bobbins, the system comprising a thread guide arranged to make pressure contact with the peripheral surface of a package as it is wound on a bobbin sleeve, and a thread guide carrier relative to which the thread guide is movable and which is driven in reciprocatory manner parallel to the longitudinal axis of the bobbin sleeve, in which the pressure with which the thread guide contacts the packages is derived from piston/cylinder drive means connected to a source of compressed air supplying compressed air at constant pressure, said piston/cylinder drive means also being in communication with pressure equalisation means which is operative in the event of an increase in pressure as a result of the thread guide moving away from the bobbin sleeve as the diameter of the wound package increases.

   2. A system as claimed in claim 1, having a plurality of winding heads at each of which there is a thread guide, in which each thread guide is provided with its own exclusive piston/cylinder drive means, and in which the piston/cylinder drive means of all the winding heads are connected in common to the same source of compressed air.

   3. A system as claimed in claim 1 or 2, in which the pressure equalisation means comprises a chamber connected into a feed pipe provided between the source of compressed air on the one hand and the piston/cylinder drive means on the other hand, the chamber having a volume which is large in comparison to the volume of said feed pipe.

   4. A system as claimed in any preceding claim, in which the source of compressed air includes an adjustable pressure regulating valve and means to indicate the pressure.

   5. A system as claimed in any preceding claim, in which the or each thread guide is subject not only to the force of the piston/cylinder drive means but also to the action of a pneumatic cylinder which is arranged to lift the thread guide away from the peripheral surface of the package and can only be actuated when the piston/cylinder drive means is inoperative.

   6. A system as claimed in any preceding claim, in which the or each thread guide is pivotally movable transversely to the longitudinal axis of the bobbin sleeve, and in which its contact surface with which the thread guide makes contact with the peripheral surface of the wound package is provided with thread guiding and/or pressure grooves matched to the thread dimensions and extending in the direction of travel of the thread.

   7. A system as claimed in claim 5 or claim 6 when dependent on claim 5, in which the or each thread guides is secured to a pivotable level connected to the thread guide carrier, and in which said lever is connected to the piston/cylinder drive means by way of a movable joint and/or is coupled to a piston rod of the pneumatic cylinder.

   8. A system as claimed in any preceding claim, having a plurality of said thread guide carriers arranged to be driven in a reciprocating manner and all secured to a common traverse frame.

   9. A system as claimed in claim 8, in which the traverse frame carries the thread guides and the piston/cylinder drive means and is powered by a roller ring transmission which is reversible by two end stops.

   10. A system as claimed in claim 9, in which the end stops are each movable to different positions corresponding to the angles of inclination of sloping faces of the end flanges of a bobbin sleeve.

   11. A system as claimed in claim 9 or 10, in which each end stop has a separately controllable setting drive.

   12. A system as claimed in any of ciaims 9 to 11, in which the end stops are mounted on respective adjustment spindles and are connected to a setting drive, the end stops being manually adjustable to a minimum distance setting corresponding to the basic traverse stroke of the thread guide, and/or in which the two setting spindles are in rotational engagement by way of an intermediate shaft which provides different settings for the end stops.

   13. A system as claimed in claim 12, in which a friction shaft of the roller ring transmission and all the winding spindles at the winding heads are connected to a main drive motor by way of an infinitely adjustable speed transmission.

   14. A thread guidance system for a winding machines substantially as hereinbefore described with reference to the accompanying drawings.

   New Claims or Amendments to Claims filed on 27/3/81.

   Superseded Claim 1 New or Amended Claims:

   1. A textile thread guidance system for a winding machine for producting parallel-wound bobbins wound with textile thread, the system comprising a thread guide having a contact surface which is arranged to slide over the peripheral surface of a package as it is wound on a bobbin sleeve and which presses the on-running textile thread, and a thread guide carrier relative to which the thread guide is movable and which is driven in reciprocatory manner parallel to the longitudinal axis of the bobbin sleeve, in which the pressure with which the thread guide contact surface contacts the package is derived from piston/cylinder drive means connected to a source of compressed air supplying compressed air at constant pressure, said piston/cylinder drive means also being in communication with pressure equalisation means which is operative in the event of an increase in pressure as a result of the thread guide moving away from the bobbin sleeve as the diameter of the wound package increases.