EP0074932A1

EP0074932A1 - Procedure for locking the torsion in long shafts and device which employs said procedure

Info

Publication number: EP0074932A1
Application number: EP82830220A
Authority: EP
Inventors: Giuseppe Bruni; Vittorio Vernocchi
Original assignee: Officine Savio SpA; Savio SpA
Current assignee: Officine Savio SpA; Savio SpA
Priority date: 1981-09-02
Filing date: 1982-08-02
Publication date: 1983-03-23
Also published as: IT8183454A0

Abstract

A procedure for locking the torsion of shafts in long spinning frames, said procedure comprising:

- start-up of the spinning frame with the device (20) for locking torsion connected up;
- the disconnecting of said devices (20) after a pre-set time long enough to cover the initial transient period;
- re-connection of the device (20) for a long enough time before the spinning frame is stopped;
- the device (20) is kept connected up while the spinning frame remains halted so as to ensure the proper working of said spinning frame when it is next started up again and so as to avoid phase displacement of the cylinders.

The invention also concerns the device (20) for carrying out said procedure and for locking the torsion of the shafts in long spinning frames, said device (20) being characterized by including in cooperation and coordination:

- transmission means (16) connected rigidly to a powered shaft (10) of the spinning frame,
- drivable coupling means (21) connected to said transmission means (16) and cooperating temporarily with at least one other shaft (11) of the spinning frame, and
- control means (22) able to operate said drivable coupling means (21) so as to suit the speed of said powered shaft (10).

Description

This invention concerns a procedure for locking the torsion in long shafts connected together mechanically; the device of the invention is applied advantageously, but not essentially, to the shafts of long ring spinning frames.
To be more exact, the invention has the purpose of pre- .venting the relative movements of two or more shafts in only .one direction of rotation when said shafts are not being rotated.
The invention can be applied to one or more shafts which are or are not parallel to each other.
According to the invention the device can be fitted to at least one end of a shaft located opposite to the end where the input of motion takes place.
Moreover, the device of the invention can be fitted to. shafts which are driven at their end or which are driven at an intermediate position
The invention can be applied in particular, but not only, to ring spinning frames and can be applied wherever conditions exist which can be related to or be likened to those of ring spinning frames.
It is known that in a ring spinning frame the device for drafting the roving consists not only of the organs able to exert pressure on the roving but also of two or more shafts which have a small diameter in relation to their length and which in this case have to rotate at speeds different from each other but having a constant reciprocal ratio.
Owing to the resisting moments acting on the shafts it happens that during the transient period of start-up of the machine the shafts undergo a torsion which grows progressively the further it is from the zone of input of motion and . the nearer it is to the opposite end zone.
This torsion occurring in the shafts becomes consider- . able, above all in especially long machines.
Since the resisting moments vary from one shaft to another, it happens that the relative rotation (that is, the . rotation lag due to the torsion occurring) between the zone of input of motion and the end zone or zones of one shaft . . is different from that of another shaft. Owing to this fact, when the resisting moments are lacking (as happens when the machine stops), the shafts, or cylinders as they are also. called, stay still in the zone where the motive moment is applied but tend, at their other end zone, to recover the angle of torsion which has progressively built up as lag since the machine was started and which exists at the time . when the machine is halted.
. Such angles of torsion are not induced according to a. ratio the same as that existing between the speeds of rotation of the shafts.
Thus, faulty drafting takes place in the phase of recovery of the torsion; that is to say, during the phase of. recovery of the induced torsion the end parts of the shafts .or cylinders can cause faulty drafting and can also lead to the possibility of causing the breakage of yarns at once or when the machine is started up once more. This shortcoming. leads to a considerable burden of work for the machine operatives and an evident lessening of output, yield and quality of the yarn. So as to keep the ratio of the angles of rotation constant even at the end section of the cylinders, some solutions have been put forward, such as those shown in patents DE-AS 26 4I 434. DE-A,S 27 22 532, DE-AS 28 17 162, DE-OS 29 30 327 and DE-PS 94895.
In those patents a system is developed which connects . the end sections of the cylinders themselves with a system of ratios the same as that which transmits the torques in the zones of input of motion of the shafts or cylinders.
Furthermore, it is envisaged in those inventions that . the connection between the cylinders is continuous, that is . to say, it is always working both when the machine is operating and also when the machine is stopped; however, this does not take into account the fact that such a connection .is not needed when the machine is running normally.
According to experiments made we have established that in the long shafts used in modern ring spinning frames the relative distortion in the drafting zone takes place during the start-up and stopping phases of the machine.
Experiments made have shown that it is important to eliminate the torsion related to the start-up of the machine and also to prevent said shafts from recovering the induced torsion whenever the spinning frame is stopped for any reason at all.
According to the invention this purpose is fulfilled .by employing a rigid connection which only works during the .start-up and stopping phases.
. The invention can also be applied where there are one .or more shafts.
Advantages of this invention are the elimination of unnecessary extra consumption of energy and of wear on the pear wheels and on the device itself and also the suppres-. sion of a possible source of unpleasant noise during the working cycle of the machine.
This invention is displayed in a procedure for locking the torsion of shafts in long spinning frames, said procedure being characterized by comprising the following phases:.

- start-up of the machine with the device connected up; - the disconnecting of the device after a pre-set time long enough to cover the initial transient period;
- reconnection of the device for a long enough time before. the machine is stopped;
- the device is kept connected up during the period while. the spinning frame is stopped so as to ensure the proper working of said frame when it is next started up again and so as to avoid phase displacement of the cylinders.

Moreover, the invention is embodied in a device for. carrying out said procedure and for locking the torsion of. .shafts of long spinning frames, said device being characterized by including in cooperation and coordination: .

- transmission means connected rigidly to a shaft of the . spinning frame,
.- drivable coupling means connected to said transmissiong . means and cooperating temporarily with at least one shaft of the spinning frame, and
.- control means able to actuate said drivable coupling means so as to suit the speed of said shaft.

. An embodiment of the device of the invention will be .described hereinafter, as a non-restrictive example, with the help of the tables, wherein:-

Fig.I gives a diagram of a spinning frame fitted with the. device of the invention;
Fig.2 shows diagrammatically the working cycle of the spinning frame and the transient periods of start-up and stopping;
Fig.3 shows the specific make-up of the control means of. the invention.

With reference to Fig.I the spinning frame comprises in its drafting unit three shafts numbered 10 (drafting), II (accompanying) and 12 (feeding) which rotate at the respective angular speeds V₁ , V₂ and V₃ transmitted to said shafts with a constant ratio by the motor 13, which is connected here to the drive shaft 10 with belts, gear wheels or like connecting means.
In particular, so as to obtain drafting of the yarn said ratio has to correspond to the difference V₁> V₂ and is established by the ratios between the pairs of gear wheels 113-110, IIO-I4, 14-111, 111-15 and 15-112, said gear. . wheels 14 and 15 being idler gear wheels, whereas the gear. .wheels 111-112 are solidly fixed to the shafts II and 12 re.- spectively.
As is known, each of said shafts 10, 11 and 12 cooper-. .ates with its relative pressure roller 210, 211 and 212 re-. spectively.
. The device 20 of the invention is fitted to the spin- .ning frame at the end of the latter opposite to the powered. .end thereof.
Said device will be described with reference to the .shafts 10 and II since the shaft I2 can possibly be connect- .ed to the other shafts by means of another device according. .to the invention.
The device 20 of the invention comprises transmission. .means 16 rigidly fixed to a shaft of the spinning frame, in. .this case to the drive shaft 10; said transmission means 16. .consist here of a gear wheel 116 keyed onto said shaft 10. and cooperating through a gear wheel 3I6 with another gear . wheel 216 keyed onto an idler shaft 311, whereby said shaft. 311 is equipped at its end with drivable coupling means 2I . which connect said shaft 311 to the shaft II at least temporarily. Said coupling means 21 consist here of a solenoid. .clutch 121 that is actuated electrically, but could also con- .sist of suitable mechanical coupling means such as clutches, .claw clutches, ratchet gears or like means which can be act- .uated with electromechanical or electromagnetic means or the like.
. Furthermore, the device of the invention comorises con- .trol means 22 able to actuate said coupling means 21 to suit .the speed of the shafts of the spinning frame, said control. .means 22 being connected to the motor 13 of the spinning .frame in this instance.
. The specific make-up of the said control means 22 is .shown diagrammatically in Fig.3.
. The control means 22 for starting and stopping the mot- .or 13, and also the coupling means 21 receive the mains sup- .ply or line supply current 8I, which feeds the motor 13 as well, through a voltage transformer 82 having several out-. puts.
Moreover, the electrical protection of said means 22 . and 21 and of the motor 13 is ensured by magnetic-thermal protective means 83-183-283-383 of a knomn type located in series in the respective supply circuits.
Further thermal protective means 84 are also pre-arranged in the supply connections of said motor 13.
To actuate said motor 13 it is enough to press the key .25, which is of a normally open type, so that the coil 85 of .the remote control switch 185 can be supplied.
Said coil 85 makes the contacts 89 close so that the .motor 13 is started. At the same time said coil 85 makes the contact 87 close, said contact 87 permitting said coil 85 to charge itself, and also makes the contact 88 close so as to connect the circuit 90 to the derived supply 86.
In this way the timer 92 can be supplied through the contact 91, which is of a normally closed type. Being fed, said timer 92 closes the contact 24 and thus enables the coil 93 to be fed.
In its turn said coil 93 closes the self-charge contact 94 and opens the contact 91 so as to start the timing cycle. for the opening of said contact 24 after a pre-set time.
Furthermore, the coil 93 closes the contact 97 of the circuit 95 so that the coupling means 21 are fed with current converted into direct current by the bridge rectifier 96.
The stopping of the motor 13 and the disengagement of . .the coupling means 2I can take place at the time T₂ owing to lack of mains current or owing to the action of the relative protective devices, or can be obtained by pressing the push. .button 23, which is of a normally closed type.
In fact, said push button 23, like the thermal protect- .ive contact 98, is located in series with the coil 85 and is therefore able to cut offi the supply thereto when it is opened.
In this way the contacts 89 can be opened so as to stop .the motor 13 and the contact 88 can be opened so as to cut . .off the supply to the coil 93.
Being no longer fed, said coil 93 permits the contact. 9.1 to close and also enables .the self-charge contact 94 and. .the contact 95 which feeds the coupling means 21, to open. again.
The final stooping of the spinning frame takes place at _.the time T_F.
Let us now see how the invention works. When the starter button 23 of the machine is pushed, the motor 13 of the spinning frcme, together with the coupling means 21 cooper- _ating with the shaft II, is started. After a given time T_I. (Fig.2), which can be regulated with the timer 24, the coupling means 21 are disengaged. When the machine stops owing. to the button 25 being pushed or owing to lack of mains current or because of the action of the protective means included in the circuit, the coupling means 21 are engaged at the time T₂ and remain so engaged until the machine has been started up once again.
It is clear that the procedure of the invention eliminates the development of the relative torsion in the start-. up phase and also the recovery of any relative torsion created between the shafts 10 and II, as said shafts 10 and 11. are connected rigidly together during the initial transient. period, in the phase of stopping the machine and during the. .period when the machine is halted.
We have described here a procedure for locking the tor_- ston of the shafts in spinning frames, and also a preferent_- .ial embodiment of a device to carry out said procedure, but. .other alternative embodiments are possible for a technician. .in this field without departing from the scope of the invent- .ive idea of this invention.

Claims

I. Procedure for locking the torsion of shafts in long spinning frames, said procedure being characterized by in- . cluding the following phases: .
- start-up of the frame with the device (20) for locking torsion connected up;

the disconnecting of said device (20) for locking torsion after a pre-set long enough time (T_I);

- re-connection of the device (20) for locking torsion for a long enough time (T₂) before the spinning frame is stop- . ped; .

- the device (20) for locking torsion is kept connected up . - while the spinning frame is halted so as to ensure the pro- . per working of said frame when it is next started up once again and so as to avoid phase displacement of the cylinders.
. 2. Procedure as in Claim I, characterized by the fact. . that the disconnecting of the device (20) for locking torsion takes place after a time (T_I) long enough to cover the. initial transient period.
3. Procedure as in Claims I & 2, characterized by the. fact that the re-connection of the device (20) for locking. torsion lasts for a period (T₂) before the stopping of the. machine (T_F) long enough to cover the transient stopping period.
4. Device (20) to carry out said procedure and the locking of torsion of the shafts in long spinning frames, characterized by comprising in cooperation and coordination:
.- transmission means (I6) connected riqidlg to a shaft (10). of the spinning frame, .

.- drivable coupling means (2I) connected to said transmission means (I6) and cooperating temporarily with at least . one other shaft (II) of the spinning frame, and

- control means (22) able to actuate said drivable coupling. means (21) so as to suit the speed of said shaft (10).
5. Device (20) for locking torsion as in Claim 4, characterized by the fact that said shaft (10) is the powered shaft of the spinning frame.
6. Device -(20) for locking torsion as in Claims 4 & 5,. characterized by the fact that said drivable coupling means. (2I) consist of an electrically operated solenoid cluich (121).
7. Device (20) for locking torsion as in Claims 4 & 5,. characterized by the fact that said drivable coupling means. (21) consist of claw clutches operated by electromechanical-or electromagnetic means.
8. Device (20) for locking torsion as in Claims 4 & 5,. characterized by the fact that said drivable coupling means. (21) consist of ratchet gears operated by electromechanical. or electromagnetic means.
9. Device (20) for locking torsion as in Claim 4 and. in one or another of the Claims thereafter, characterized by .the fact that said control means (20) are connected to the . .motor means (13) which drive the powered shaft (10) of the. spinning frame.
. 10. Procedure for locking the torsion of shafts in spin- .ning frames, being substantially as described, shown and claimed and for the purposes allowed.
11. Device (20) for locking the torsion of shafts in long .spinning frames, being substantially as described, shown and claimed and for the purposes allowed.