US3803823A

US3803823A - Control apparatus for textile machinery

Info

Publication number: US3803823A
Application number: US00200113A
Authority: US
Inventors: G Hoeber; H Niestroj; H Landwehrkamp
Original assignee: Schubert und Salzer Maschinenfabrik AG
Current assignee: Rieter Ingolstadt Spinnereimaschinenbau AG
Priority date: 1970-11-28
Filing date: 1971-11-18
Publication date: 1974-04-16
Anticipated expiration: 1991-04-16
Also published as: IT940792B; GB1346333A; BR7107797D0; ES397065A1; BE775902A; FR2115836A5; CA966910A; AR192329A1; CH528607A; DE2058602A1; NL7116278A; AT313757B

Abstract

The specification describes a control apparatus for textile machinery for the actuation of actuating parts in a timed sequence in accordance with a change in yarn tension. The apparatus comprises a pulse stage, a first operating part arranged to be controlled by the pulse stage, a second operating part, and a delayed action timing stage arranged to actuate the second operating part.

Description

United States Patent [191 Niestroj et a1.

CONTROL APPARATUS FOR TEXTILE MACHINERY [75] Inventors: Heinrich Niestroj, lngolstadt; Hans Landwehrkamp, Gerolfing; Gerhard Hoeber, lngolstadt, all of Germany [73] Assignee: Schubert & Salzer Maschinenfabrik Aktiengesellschaft, lngolstadt, Germany [22] Filed: Nov. 18, 1971 [21] Appl. No.: 200,113

[30] Foreign Application Priority Data Nov. 28, 1970 Germany 2058602 [52] US. Cl 57/34 R, 57/58.95, 57/93 [51] Int. Cl. D0lh 15/00, DOlh l/12 [58] Field of Search.. 57/34 R, 80, 81, 58.89-58.95,

[56] References Cited UNITED STATES PATENTS 3,660,972 5/1972 Neill et a1. 57/34 R [111 3,803,823 [4 1 Apr. 16,1974

3,354,631 1l/1967 Elias et a1. 57/58.95 3,462,936 8/1969 Boucek et al..... 57/80 3,540,201 l1/l970 Susami et al 57/80 3,541,774 11/1970 Sterba et a1 57/58.95 X 3,673,591 6/1972 Schwartz 57/81 X Primary Examiner-John Petrakes Attorney, Agent, or Firm-Robert W. Beach; R. M. Van Winkle 57 I ABSTRACT The specification describes a control apparatus for textile machinery for the actuation of actuating parts in a timed sequence in accordance with a change in yarn tension. The apparatus comprises a pulse stage, a first operating part arranged to be controlled by the pulse stage, a second operating part, and a delayed action timing stage arranged to actuate the second operating part.

18 Claims, 8 Drawing Figures PATENTEDAPR 16 I974 SHEET 1 [IF 5 WMM 7 PATENTED APR 16 I874 sum 3 or 5 A ffd/P/VZ/ PATENTEDAPR 16 I974 sum 5' or 5 ArraeA/i/ CONTROL APPARATUS FOR TEXTILE MACHINERY BACKGROUND OF INVENTION 1. Field to which Invention Relates The present invention relates to a control apparatus for textile machinery, and more particularly to such an apparatus for open-end-spinning machines with differently timed actuation of several switching parts in accordance with a change in thread tension.

2. The Prior Art If in so-called open-end-spinning machinery yarn or thread breakage occurs, the thread end must be introduced into the spinning device again and connected with the fibres deposited in the device on a collecting face, for example the controlling groove of a spinning turbine (U.S. Pat. specification No. 3,440,812) or in a rotating or stationary spinning funnel (Czech Pat. specification No. 87,947 and Japanese Pat. application No. 24.0S1/63). The fibres can, however, be placed directly on the yarn end, which in this case freely rotates (U.S. Pat. specification No. 2,911,783). In order to ensure that the yarn end does not leave the spinning device the control device for dealing with the yarn breakage must respond very rapidly or the draw-off tube of the spinning device. Otherwise automatic piecing-up of the yarn and of the spinning operation would not be possible or would only be possible with the adoption of complicated features and considerable delays. For this purpose a control device has been proposed which is switched on by the control contact of a yarn monitoring device via a control relay, which control device decouples a coupling or clutch operating draw-off mechanism and switches on a coupling bringing about the return of the yarn into the spinning turbine. Simultaneously the supply of fibres is stopped bythe operation of a turbine (see Czech Pat. specification No. 129,441). Simultaneously the supply of fibres is stopped by the operation of an electromagnet. When the thread end has passed through the sensing means or feeler on being returned into the spinning turbine, the feeler switches on a timing device which switches on, via the above-mentioned electromagnet, the supply of fibre when a certaintime has elapsed. Moreover with the help of an electromagnet the feeler ensures that a cam is coupled with a drive device and when a certain angular position has been reached the cam switches off the control relay so that the coupling for the return of the thread or yarn into the spinning device is disconnected and the coupling for restarting of thread drawofi" is switched on again. Simultaneously by the deenergisation of the control relay the timing device or timer is switched off and the cam is disconnected from its drive device so that the cam comes to stop in a certain angular position. Thiscontrol device comprises a large number of mechanical switching parts which mean that a certain delay cannot be avoided. Particularly in the caseof rapidly operating open-end-spinning devices, in which a very rapid response of the return device and a very exact matching of the various control times is necessary, the mechanical control devices and contacts give rise to errors in timing which mean that it is not possible to deal reliably with yarn breakages.

Moreover the mechanical switching or operating parts are liable to wear and therefore bring about a still further reduction in the accuracy of switching and require careful servicing. In order to increase the switching and return speed there has already been a proposal to guide the length of thread or yarn running back into the spinning device so as to take the form of a reserve loop and to actuate a contact by means of the deviated thread which is unloaded when the thread or yarn breaks (German Pat. specification No. 1,288,965). In this case the deviated thread is released via an electromagnet and the thread deviates owing to gravity approaches the draw-off tube opening, into which the thread is sucked owing to the vacuum existing in the spinning device. In order to actuate the switching contact it is necessary, however, in thecase of this arrangement to overcome a comparatively large moment of inertia so that the necessary speed of switching cannot be obtained with this device either. Furthermore, this previously proposed device does not deal with the problem of precise timing in sequence of the various operations.

SUMMARY OF INVENTION One aim of the invention is therefore that of avoiding the disadvantages mentioned above in connection with previously proposed devices and to provide a control device which is practically free of inertia in operation and therefore has as few as possible or no mechanically moving parts and which can operate any desired number of switching parts at the desired time for a period in time to be determined.

The present invention consists in a control apparatus for textile machinery for the actuation of actuating parts in a timed sequence in accordance with a change in yarn tension, comprising a pulse stage, a first operating part arranged to be controlled by the pulse stage, a second operating part, and a delayed action timing stage arranged to actuate the second operating part. With the help of the pulse stage on actuation of the .feeler very rapid control operations are immediately driven, such as for example the release of a thread or yarn reserve of an open-end-spinning machine in accordance with the method of the U.S. Pat. application Ser. No. 93,552 of 30/11/1970, so that the thread reserve can be drawn back into the device owing to the vacuum existing in the spinning device. The second switching part switched on by the timingstage whose actuation is delayed serves in the case of this open-endspinning device for example for stopping the supply of fibres until that point in time at which the feeler registers the presence of a normal yarn or thread tension.

In order in the case of variations in yarn or thread tension to avoid multiple rapidly following responses of the pulse stage it is preferred to provide means to ensure that the capacitor can rapidly be discharged. For this purpose the pulse stage comprises a capacitor which, in accordance with a further feature of the invention, is connected with a diode blocking the flow of current in the discharge direction and with a high resistance discharge resistor in parallel with the diode. In order in every case, independently from any preceding charging operation, to ensure a constant delay in actuation of the timing stage the latter has a capacitor which is connected with a diode blocking the flow of current in the charging direction and, parallel to the diode, a high resistance charging resistor.

In accordance with the construction of the device to be controlled from the control device it may be convenient if a switching pulse is generated with a certain delay. In accordance with the invention with the delayed action timing stage a pulse stage can be connected for controlling a further switching operation. It is also possible to connect the delayed action timing stage with a further delayed action timing stage for controlling a further switching or operating part, for example in order in the case of a spinning machine with a number of spinning stations, to switch off the spinning station when normal yarn draw-off tension cannot be restored even after a certain time has elapsed since switching off the corresponding feeding device.

In order for the pulse stage or stages to be able to become effective on the switching-on operation as well as independently from the instantaneous yarn tension the corresponding pulse stage or stages can be connected with a supply line which can be provided with voltage by means of a manually operated switch, for example via a programming device and the supply line is connected between the base of a transistor and a capacitor of the pulse stage. In order for the switching part connected with this pulse stage only to receive one current pulse independently of the time the switch is actuated, a capacitor is preferably arranged in the supply line and can be connected by the switch selectively on actuation of the switch with the minus pole of a DC circuit, and the switch on being released connects the capacitor with a discharge circuit provided with a resistor.

The control device in accordance with the invention is intended to operate very rapidly. It is therefore not sufficient for the elements operating in accordance with the feeler sensing the yarn or thread to operate rapidly themselves, but the contact or contacts must be actuated very rapidly, too, by the actuation of the feeler. On the other hand slight variations in the yarn or thread tension, which may occur, should not themselves lead to actuation of the switching operation. It is therefore necessary for the control device to be capable of being set very precisely in order to be able to determine the desired limits of switching and thus the response sensitivity. In accordance with the invention the control device can for this purpose comprise a feeler which is constructed as a spring, extends substantially along a straight line and is fixed at one end with a predetermined pretension. Preferably a setting or adjusting screw is provided to the side of the feeler in order to act upon it so that the pretension and thus the response sensitivity of the control contact can be regulated by a simple turning of this adjusting screw. In order to avoid bouncing of the feeler and thus possible multiple response of the pulse stage the contact cooperating with the feeler is preferably arranged on one longitudinal side and a damping device is arranged on the other side of the feeler.

In order to avoid inaccuracy in switching owing to mechanical switching tolerances, a control switching means to be operated by the feeler without touch is preferably provided and this control contact can be operated to pneumatically or optically. Preferably the control switching means is constructed in the form of a proximity switch.

A further increase in switching accuracy can be achieved by guidance at a position adjacent to the feeler of the yarn or thread to be sensed, since in this manner the yarn tension always acts in the same direction with respect to the feeler. In accordance with the invention the part, in contact with the thread or yarn (the feeler) can be arranged between two guide saddles which preferably are attached rigidly on a housing surrounding the control switching means.

Thread or yarn monitoring devices have admittedly already been proposed in which the feeler is in the form of a spring and is fixed at one end (Czech patent specification No. 123,769). However, in that case the feeler does not extend along a straight line but is bent in the form of a semi-circle and its free end closes an electric contact. Such a feeler is, however, very sensitive mechanically and can easily be distorted by bending so that there is a very great danger of the free feeler end guided in the housing becoming jammed. Furthermore, owing to the friction on the housing and the curved form of the feeler the switching speed cannot be precisely set in advance so that this device does not operate with the desired precision either. Furthermore, the curvature of the spring makes a comparatively large operating displacement necessary for closing the switching contact. The device in accordance with the present invention on the other hand is robust and mechanically insensitive so that it does not require servicing and operates extremely rapidly and precisely. Furthermore, it can easily be adjusted. Since, furthermore, there is no attempt to avoid inertia, as is the case with previously proposed devices (German Specification No. 1,560,334, German utility model No. 1,993,869) by using permanent magnets, there is no mistiming owing to hysteresis.

LIST OF SEVERAL VIEWS OF DRAWINGS Further details of the invention are described with reference to the accompanying drawings.

FIG. 1 is a block circuit diagram of the control device in accordance with the invention.

FIG. 2 is a circuit diagram of a first embodiment of a control device in accordance with the invention.

FIG. 3 shows a further embodiment of the subject matter of the invention.

FIG. 4 shows diagrammatically the control device in accordance with the invention in conjunction with an open-end-spinning device.

FIG. 5 shows a feeler in accordance with the invention for actuating the control device, in section.

FIGS. 6 and 7 show further embodiments of the feeler shown in FIG. 5.

FIG. 8 shows a further embodiment of the control device with a feeler in the form of a proximity switch.

DESCRIPTION OF PREFERRED EMBODIMENTS In accordance with the block circuitdiagram of FIG. 1 the control device 1 comprises a feeler 10 which monitors the yarn or thread tension and in accordance with the tension drives both a pulse stage 2 and also a delayed action timing stage 3 operating independently from the pulse stage 2. Each of these two stages comprises a timing

member

20 and 30, respectively, and also a switching

member

21 and 31, respectively. In accordance with the timing

members

20 and 30, respectively, a first switching part 4 and a second switching part 5 are actuated for the desired period of time.

As can be clearly seen in FIG. I the switching member 21 is closed very rapidly for a short period of time so that the switching part 4 connected with it responds for a short period of time as determined by the timing member 20. Unlike the pulse stage 2 the timing stage 3 delays the actuation of the switching member 31 which after responding remains in the closed condition timing stages (not shown) can be driven by the timing stage 3 or can be arranged parallel to the latter,

The circuit of a first embodiment of a control device 1 in accordance with the invention is shown in FIG. 2. In the case of this embodiment the feeler has two

control contacts

11 and 12, of which the control contact 11 is associated with the pulse stage 2 and the control contact 12 is associated with the delayed action timing stage 3. The two contacts are connected mechanically with each other and are thus actuated by the thread or yarn (not shown) in accordance with its tension. Each

control contact

11 and 12 is connected via a

resistor

23 and 32, respectively, with the minus pole 61 of a DC circuit.

The timing member of the pulse stage 2 comprises a resistor 22 which is connected in series with the resistor 23 and in parallel with the control contact 11. Via the two

resistors

22 and 23 the plus pole 60 and the minus pole 61 of the DC circuit mentioned are connected with each other. A capacitor 24 is arranged between these two

resistors

22 and 23 and is connected together with the resistor 22 so as to be parallel to the control contactvll of the feeler 10. A connecting line between the resistor 22 and the capacitor 24 is connected via a resistor 72 with the base of a transistor 70 of the switching member 21. This transistor 70 is connected with a second transistor 71 in accordance with a Schmitt trigger circuit, whose base is connected with the collector of the transistor 70 and whose emitter is connected with the emitter of the transistor 70. The two emitters are connected jointly via a resistor 73 with the plus pole 60, while each collector of the two

transistors

70 and 71 is connected via a

resistor

74 and 75, re spectively, with the minus pole 61 of the abovementioned DC circuit.

Although if it provides sufficient power the switching member 21 can be used directly for controlling the switching part 4, it is preferred to provide a power switch 40. This can for example be made up of a thyristor 41 and a protective resistor 42 in the igniting line of the thyristor 41. In series with the thyristor the switching part 4 to be operated is placed. The switching part 4 is supplied from a source of AC. The minus pole 61 of the DC circuit is simultaneously connected with the AC source, while the other connecting point 62 of the AC circuit is completely separate from the DC circuit. j

In order to protect the thyristor 41 against excess voltage, a varistor 43 is connected in parallel to the switching part 4.

The control contact 12 of the switching feeler 10 is connected via a resistor 32 with the minus pole 61 of the DC circuit and directly with the timing member 30 of the delayed action timing stage 3. This timing member 30 comprises a resistor 33, via which the feeler 10 is connected with a transistor 34 of the switching member 31. The emitter of this transistor 34 is connected via a Zener diode 35 of the timing member 30, which determines the switching point of the transistor 34, with the plus pole 60 of the DC circuit. Between the base of the transistor 34 and the resistor 33 there is a capacitor 37, also connected with the plus pole 60, to provide a connection with. the base line.

The collector of the transistor 34 is connected via a resistor 38 with the minus pole 61 of the DC circuit. For the reasons already given in connection with the pulse stage 2 the transistor 34 does not serve for directly operating the switching part 5 and instead drives a load switch 50 consisting of a thyristor 51 and a protective resistor 52 in its igniting line.

In order to avoid AC ripple a rectifier 53 is provided as a zero diode parallel to the switching part 5.

FIG. 4 shows the control device 1 in accordance with the inventionin conjunction with an open-end-spinning device in accordance with the U.S. Pat. application Ser.

No. 93,552 of 11/30/1970. This device comprises a spinning device 8 operating with vacuum, and from which the spun thread 13 is drawn off by means of draw-off

rollers

81, 82 through a draw-off tube 80. The drawn off thread or yarn 13 is then wound on a bobbin 83. Between the draw-off

rollers

81, 82 and the bobbin 83 the thread or yarn 13 is guided by means of two

yarn guiding parts

14 and 15, between which it is displaced, by means which are not shown, to form a yarn reserve and is held in this condition by a forked deviation 16. The deviation 16 is placed at the end of an am of a three-armed lever mechanism 18, which can be pivoted about a pin or axis 19. On a further arm of this lever mechanism 18 an ejector 17 is mounted, while the third lever arm, not shown, serves for returning the deviation 16 behind a stripping edge 84 and thus for ejecting and releasing the yarn reserve and for pressing the yarn 13 out of the nip line of the draw-off

rollers

81, 82 by means of the ejector 17. The lever mechanism 18 is operated for this purpose by means of a switchingpart 4 driven by the'control device 1. The spinning device 8 is supplied with fibres by a feed device 85. This feed device comprises a switching part 5 for stopping or switching off the supply device 85.

; The control device described above with reference to FIG. 2, and which in FlG. 4 is shown in conjunction with an open-end spinning device in order to make it more readily understandable, operates in the following manner:

In the case of normal yarn tension, as present at the feeler 10 when the yarn or thread 13 is drawn off properly by a spinning device 3, the feeler 10 is held closed by the yarn or thread 13. The two

control contacts

11 and 12 are thus also held in the closed condition. The DC therefore flows from the plus pole 60 via the

closed control contacts

11 and 12 and the

resistors

23 and 32 to the minus pole 61. Since there is no voltage drop between the plus pole 60 and the adjacent ends of the re- '

sistors

23 and 32, no current can flow to the

capacitors

24 and 37 so that the latter can also not be charged. Furthermore, there is no voltage at the bases of the transistors and 34 so that the latter are in the blocked condition. Furthermore, there is no voltage drop at the resistor 74 so that the base of the transistor 71 is negative with respect to the emitter and the transistor 71 is thus in the conducting condition. Therefore DC flows from the plus pole 60 via the resistor 73, the transistor 71 and the resistor 75 to the minus pole 61. Since no current flows through the transistor 70, no igniting current flows to the load switch 40 so that the latter remains in the blocked condition.

Furthermore, no igniting current passes to the load switch 50 since the transistor 34 is in the blocked condition. The switching part is therefore not switched if now owing to a drop in the yarn tension the

control contacts

11 and 12 of the feeler are opened, the DC must flow from the plus pole 60 via the resistor 22 to the capacitor 24 and the resistor 23. Thus, the capacitor 24 becomes charged. The two

resistors

22 and 23 are of low ohmic values and the capacitor 24 has a low capacity so that the capacitor is charged within a very small precisely defined time. During the charging of the capacitor 24 the transistor 70 becomes conducting on achieving the bottoming until the charging operation is finished. During this short period of time a pulse flows from the plus pole 60 via the resistor 73, the transistor 70 and the resistor 74 to the minus pole 61. Therefore, the same voltage is present at the base of the transistor 71 as at its emitter so that it is swung over into the blocking condition. Owing to the voltage pulse, however, the thyristor 41 of the load switch 40 is ignited for a short period of time. Since the thyristor 41 operates like a rectifier, it only allows the passage of the current flowing from the connection point 6 to the minus pole 61 connected with the AC source. The pulse produced by the charging of the capacitor 24 in accordance with the bottoming voltage of the transistor 70 is therefore to be so dimensioned that it lasts longer than an AC half cycle so that even a pulse which begins during the AC half cycle opposite to the conducting direction of the thyristor 41 can ignite the thyristor 41 during the half cycle corresponding to the conduction direction of the thyristor 41.

During the period in which the thyristor 41 is ignited the switching part 4, for example an electromagnet, is switched on. This switching part 4 swings the lever mechanism 18 so that the ejector l7 presses the thread or yarn 13 out of the nip line of the draw-off

rollers

81 and 82. Simultaneously the deviation 16 is drawn back behind the stripping edge 84 so that the yarn reverse is thrown off from the deviation 16. The yarn reserve acted upon by the vacuum present in the draw-off tube 80 is therefore very quickly drawn back into the spinning device 8, in which the yarn end becomes connected with the fibres fed by the feeding device 85. The yarn tension restored, so that the yarn 13 passes into the nip line of the draw-off

rollers

81, 82 again and is drawn out of the spinning device 8 again. The feeler 10 becomes subjected to the normal yarn tension and the

control contact

11 and 12 are again closed. Accordingly the capacitor 24 can discharge via the resistor 22 and the control contact 11.

In order to achieve a rapid response of the switching part 4 this latter is preferably connected with the voltage which is many times greater than that for which it is designed. For example, the switching part 4 is designed for an AC of 24 V but is connected with an AC of 90 V. The electromagnetic action is therefore so great that an exactly determinable slight delay in time occurs, which can be compensated for by a suitable dimensioning of the timing member 20.

When the yarn tension drops opening of the control contact 12 causes the current to flow from the plus pole 60 of the DC circuit via the capacitor 37 and the two

resistors

33 and 32 to the minus pole 61. The resistor 33 has a high ohmic value and also the capacity of the capacitor 37 is large, so that the capacitor 37 requires a fair time to charge. If during this time the normal yarn tension is not restored so that the capacitor 37 is charged up to the blocking voltage laid down by the Zener diode 35, the transistor 34 passes over into its conducting condition.

Thus, current flows from the plus pole 60 of the DC circuit via the diode 35, the transistor 34 and the resistor 38 to the minus pole 61, while at the same time current flows to the power switch 50. Thus, the thyristor 51 is ignited via the resistor 52 so that the switching part 5 is supplied from the connection point 6 and from the minus pole 61 also connected with the AC source. Since the thyristor 51 can only be supplied with current in every second half cycle, a diode 53 is connected in parallel to the switching pan 5 and the diode prevents an excessively rapid decrease in the electromagnetic field and thus ensures stability of the voltage at the switching part 5. The switching part 5 switches off the supply device so that no more fibres are supplied to the spinning device 8.

The switching part 5 remains switched on until the transistor 34 returns into its blocked condition and the thyristor 51 is blocked the next time the AC passes through zero. The transistor 34 is blocked when the control contact 12 comes into the closed condition with sufficient yarn tension, so that the capacitor 37 discharges through the control contact 12 and the resistor 33 and the level sinks to below the switching limit of the transistor 34 determined by the Zener diode 35.

As the above-mentioned description shows it is possible with the control device to actuate differently timed switching operations without it being necessary to use for this purpose any mechanically moved parts apart from the two

control contacts

11 and 12 for the feeler 10. By the construction of the

resistors

22 and 23 as potentiometers or by construction of the

capacitors

24 and 37 as rotary capacitors it is possible to change the time constants of the

timing members

20 and 30 so that matching to individual requirements becomes possible.

The individual components of the control device 1 can also be modified. FIG. 3 shows a modified feeler 10', a modified timing member 20, a modified switching part 21' and a modified power switch 48. The feeler 10' is simpler than the feeler 10 shown in FIG. 2 and both for the pulse stage 2 and also for the delayed action timing stage 3 only has a single common control contact 11. This control contact is connected on the one hand with the positive pole 60 of the DC circuit and on the other hand via a resistor 23' with the minus pole 61 and also with the pulse stage 2 and the time stage 3. Thus, the resistor 23' serves both for charging of the capacitor 24 (with the help of the resistor 22) and also of the capacitor 37 (with the help of the resistor 33).

In certain circumstances short duration tension changes may be registered by the switching feeler 10, which cause a rapid sequence of opening and closing movements of the control contact 11 or the

control contacts

11 and 12. In the case of previously described embodiments of the subject matter of the invention this would lead to a repeated response of the switching part 4, something which, however, should be avoided. lf this control device is used in conjunction with an open-endspinning device in accordance with FIG. 4, such a vibration of the switching pan 4 would certainly lead to a yarn breakage. In order that this switching part is only capable of responding once within certain timing limits, the capacitor 24 is connected via a diode 28 blocking the flow of current from the

control contact

11 or 11, respectively, to the capacitor 24. The diode 28 is connected in parallel to a resistor 29 with a high value. When the

control contact

11 or 11, respectively, is closed, the capacitor 24 can therefore only discharge via the high value resistor 29 and an abrupt discharge of this capacitor 24 is avoided. If the control contact 1 l or 11 respectively, is opened once again after the first opening, the capacitor 24 will not have yet been discharged as far as below the switching level of the transistor 70, so that the load switch 40 is not changed.

Since the current flowing in accordance with the switching limit of the transistor 70 of the switching stage 21 has very steep rising flanks and also comparatively steep trailing edges, it is not necessary to provide a Schmitt trigger in accordance with FIG. 2 for the switching stage 21. In accordance with FIG. 3 the second transistor 71 with the resistor 75 associated with it can be dispensed with. Instead of the resistor 73 a diode 76 is provided which also prevents-a bottoming of the transistor 70 even after a drop-in voltage at the capacitor 24 owing to heating.

The conducting time of the thyristor 41 of the load switch 40 is, as already mentioned, determined by the ignition time, which is determined by the time extend ing from the moment at which the bottoming voltage of the transistor is reached to the complete charging of the capacitor 24 and also by the time during which the AC half cycle corresponds with the conducting direction of the thyristor 41. The ignition time of the thyristor 41 can be substantially shortened when the voltage half cycles, which correspond with the conducting direction of the thyristor, were to follow each other more rapidly. In orderto ensure this, in accordance with FIG. 3, the load switch 48 is provided with a rectifying bridge made up of the diodes 44, 45, 46 and 47, owing to which all voltage half waves correspond with the conducting direction, of the thyristor 41.

If the thyristor 41 and the switching part 4 are connected with mulfi-phase supply a conventional rectifying bridge made up of six diodes can be used to obtain a further increase in the switching accuracy. Also, the delayed action timing stage 3 can be constructed differently. The timing part 30" shown in FIG. 3 has a discharge diode 39, parallel to the resistor 33, in order to make possible a rapid discharge of the capacitor 37 so that the timing member becomes fully functional rapidly. The capacitor can only be charged via the resistor 33 slowly, since the diode 39 blocks the current in the charging direction but discharges very rapidly via the control contact 11' or 11, respectively, and the discharge diode 39.

In the construction described the control device 1 in accordance with the invention serves for controlling a pulse-like switching operation and a long time switching operation. It is also quite possible to arrange several pulse stages and/orseveral delayed action time stages so as to be respectively parallel to each other. Such a further pulse stage is to be connected on the one hand between the resistor 23 and the control contact 11 with the feeler l0 and on the other hand with the plus pole 60 of the DC circuit, while in an similar manner a further delayed action time stage is connected between the resistor 32 and the control contact 12 with the feeler l0 and on the other hand is connected with the plus pole 60. The timing member of the additional pulse stage is set differently to the timing member 20 of the pulse stage 2 and the timing member of the additional delayed action time stage is differently set to the timing member 30 of the timing stage 3 so that the corresponding switching parts respond at different times.

Naturally such an additional pulse stage can comprise an identical circuit like the timing member 20' so that in this case as well rapid discharge of the capacitor is avoided. Owing to the delayed action timing stage-it is not absolutely necessary for a switching part to directly respond and it is quite possible for such a member to control one or more further pulse stages 2'. These pulse stages 2' are constructed so as to be precisely the same as the pulse stage 2. Therefore corresponding parts are denoted by reference numeral with apostrophes in accordance with the pulse stage 2. They correspondto each other: transistor 70 corresponds to transistor 70' and resistor 74 corresponds to resistor 74' etc. In accordance with FIG. 3 a further timing member 25 is connected with the timing member 30. This, like the timing member 20 has a resistor 26 which in the construction shown is constructed as a potentiometer and also has a capacitor 27. The one side of the capacitor 27 is connected with the connecting line between the Zener diode 35 and an additional resistor 36 of the timing member 30 and the other side of this capacitor 27 is connected on the one hand via the resistor 26 with the positive pole of the DC circuit and with a switching part 21' on the other hand.

As long as the transistor 34 is in the blocked condition, no current flows through the resistor 36 so that no voltage drop can occur in this case. Furthermore, accordingly no current can flow through the capacitor 27 so that this latter remains in the discharged condition. If the transistor 34 becomes bottomed, current flows both via the resistor 36 and also via the resistor 26 and the capacitor 27 and the capacitor is charged up. On achieving the bottoming voltage of the transistor connected with the capacitor 27 an ignition pulse is produced which for a short time switches on the switching part 4' connected with this pulse stage 2'.

Instead of a pulse member a further delayed action time stage 3' can be connected withthe timing member 30 as well. The timing stage 3' is constructed like the timing stage 3. The timing member of this additional timing stage is connected in the same manner, as indicated for the timing member 25 of the further pulse stage, with the timing member 30. The additional timing stage can, for example, serve to switch off the spinning unit in question when the thread or yarn tension cannot be restored within a certain period after switching off the feeding device 85.

Although in the embodiment described the various pulse stages 2, 2' and timing stages 3, 3 only control one

respective switching part

4, 4 and 5, 5', it is naturally possible for one of these stages to actuate more than one switching part, if this should be appropriate.

The control device 1 in accordance with the present invention can be used particularly advantageously in dealing with yarn breakage in open-end spinning devices but can also be used successfully in the case of other textile machines in which in accordance with yarn tension changes switching parts are to be actuated at different times. Thus, such a device can be used for monitoring yarn tension of yarn or thread coming from bobbins, warp beams or the like.

It is often desired to cause the pulse stages 2 and 2', respectively, to respond independently of the feeler and 10', respectively. For this purpose the pulse stage 2 and/or the pulse stage 2' is provided with a supply line 63 which is supplied by a hand-operated switch 64 (FIG. 2) with voltage. For example, this switch 64 is actuated by a program drum, which controls the switching-on program of the machine and which on actuation of the machine main switch is switched on by the latter. The supply line is for this purpose at one end connected with the minus pole 61 of the DC circuit and the other end is connected between the base of the transistor 70 or 70', respectively, and the capacitor 24 or 27, respectively, so as to make a connection with the pulse stage 2 or 2', respectively. The diode 25 shown and the resistor 66 only serve for protecting the

transistor

70 or 70, respectively.

If the switch 64 is closed, current flows from the positive pulse 60 of the DC circuit via the resistor 22 and, if provided, the resistor 72 to the supply line 63 and via the resistor 66, the diode 65 and the switch 64 to the minus pole 61. Consequently the base of the

transistor

70 or 70, respectively, is connected with voltage and is switched through so that the thyristor 41 or 41', respectively, is ignited. In order to ensure that this current only acts in the manner of a pulse, a capacitor 27 is connected in series with the switch 64 and the diode 25 and also with the resistor 66. Thus, for the duration of the charging of the capacitor 67 a current can flow and the transistor 70 or 70', respectively, is switched only during this period in time. If the switch 64 is released, the capacitor 67 discharges via a resistor 68 connected in series with the capacitor 67 by release of the switch 64.

Preferably the unit consisting of the switch 64, the capacitor 67 and the resistor 68 is only provided once on a given machine and used with a number of spinning stations, as is indicated by the line 63'.

In order to ensure that precisely timed response of the load switches 40, 40, 50 and 50' occurs, it is not sufficient for'the electronic switching elements of the pulse stages 2 and 2 and the delayed response timing stages 3 and 3 always to work with the same accuracy. Also, the feeler 10 or 10', respectively, must operate with the same degree of accuracy. In this respect if possible it should take up slight yarn tension variations. For this purpose the control device has, in accordance with the invention, a feeler which is in the form of a spring and, with a certain pretension, is held at one end. Furthermore, the feeler extends substantially along a straight line. Such a construction of the subject matter of the invention is shown in FIG. 5. The yarn monitoring device has a holder 91 which is for example attached by means of a screw connection 90 in an adjustable manner on the machine frame. The feeler 9 is held at one end in the holder 91 and consists of a spring wire or piece of sheet metal. The bead 92 provides for pretensioning of the feeler 9 on which it rests. The holder has a plate 93 which on the side opposite to the bead covers the feeler 9. This plate 93 extends over a distance many time the spacing between the position of holding 94 and the head 92 and at its free end carries a contact screw 95 against which the feeler 9 lies as long as the yarn 13 lying against the free end of the feeler 9 has a sufficient tension. The feeler 9 together with the contact screw forms the control contact 11 shown in FIG. 3 and is connected via the

lines

96 and 97 with the pulse stage 2 and the delayed action time stage 3. Since the control contact 11 is closed neither of the

capacitors

24 or 37 is charged, so that none of the

switching parts

4 and 5 responds. If the yarn tension decreases, the feeler 9 is raised from the contact screw 95, so that the control contact 11' is opened.

Advantageously, as is the case with the embodiments described, the control contact 11' or the

control contacts

11 and 12 are always closed, if a sufficient yarn tension is present. This ensures that the control device operates even in the case of damaged

control contacts

11' or 11 and 12 and brings about the switching ofi of the corresponding spinning unit.

The pretensioning of the feeler 9 is intended to prevent an excessively rapid response of the control device 1. Owing to this it is possible with the help of the spring constants to predetermine that point at which the feeler 9 makes contact with the contact screw 95 and the control contact 11' is closed. Since the feeler 9 has only a very small mass, it operates with practically no inertia. Since furthermore it operates without the aid of magnets, it always operates with the same speed.

A similar construction to that of FIG. 5 is shown in FIG. 6. In this case the feeler comprises a strip spring 100, which prevents lateral swinging or vibration of the feeler and cooperates with a spring wire 101, soldered to the feeler, for sensing the thread 13. The strip spring 100 and part of the spring wire 101 are located in a housing 102 whose ends are closed. The end of the housing 102 adjacent to the thread 13 to be sensed has a slot 103 in which the spring wire 101 can move. The strip spring 100 is held fast in the bottom or wall 104, remote from the yarn 13 to be sensed, of the housing 102. In this wall 104 a further strip spring 106 is held whose pretensioning can be set by means of a setting screw 10S acting laterally on the strip spring 106. Thus, by a simple, turning of the setting screw 105 the pretensioning or biasing of the strip spring 106 can be set and thus with it the response sensitivity of the control device 1.

The strip springs 100 and 106 together form the control contact 11' and are connected via

lines

96 and 97 with the pulse stage 2 and the timing stage 3. In order to prevent continued vibration of the feeler on reduction in the yarn tension the feeler is provided with a damping means 107 which is located on the side of the housing 102 opposite to the setting screw 105. In the arrangement shown the damping means 107 is formed by an elastic insert, for exmaple of rubber, in the slot 103.

In order to increase the switching accuracy the yarn 13 is passed before and after passing the feeler through respective guide saddles 108.

The arrangement shown in FIG. 7 is very similar to that shown in FIG. 6. Instead of a strip spring 106 serving as a contact there is in this case, however, a contact screw 95 again, opposite which a screw 109 with a damping means 110 is located. On the same side as the damping means 110, though adjacent to the wall or bottom 104, there is a setting screw 105 for adjustment of the pretensioning of the

feeler

100, 101. In this case as well for guiding the yarn 13 two yarn saddles 108 are again provided, which in the case of this construction are, however, connected with the housing 102.

In order to avoid a mechanical switching contact in the yarn monitoring means, the feeler of the construction in accordance with FIG. 8 is constructed as a twoarmed lever 111 which at its end remote from the yarn 13 to be sensed has a permanent magnet 112. The lever 111 can be swung about a pin 113 extending transversely through the housing 102. The permanent magnet 112 is arranged to cooperate with the proximity switch 114 connected with the housing 102 and arranged between the

lines

96 and 97. This proximity switch 114 is in the closed condition as long as the permanent magnet 112 is immediately adjacent to it. If the permanent magnet 112 is out of the way, that is to say away from the proximity switch 114 on the tension of the yarn decreasing, the proximity switch 1 14 is opened and thus brings about a charging of the

capacitors

24 and 37. t

For setting the response accuracy of the yarn monitoring device means can be provided for relative setting of the permanent magnet 1 l2 and the proximity switch 114. In this case it is of no import whether the proximityswitch 114 is adjusted in relation to the permanent magnet 1 12 or whether the latter is adjusted in relation to 'the proximity switch 114, for example by it being carried by an adjustable eccentrically mounted shaft 113. v

In this case as well guide saddles are provided for guiding the yarn l3-at a position adjacent to the feeler. The guide saddles are, however, in the case of this construction constructed as U-shaped recesses 11S provided in the housing 102.

If two

control contacts

11 and 12 are to be provided in accordance with'FIG. 2, two proximity switches have to be used, between which the permanent magnet 112 can move. Thus, on its swinging movements the permanent magnet 112 actuates both control contacts so that by a suitably offset arrangement of these proximity switches different-actuating times can be attained.

Instead of proximity switch 114 it is also possible to provide another switch operating without mechanical contact, such a switch being actuated for example pneumatically or optically or in a similar contactless manner.

As the above description shows, many modifications of the subject matter of the invention are possible. It is only essential that the control device should not have any factors leading to uncertain operations through mechanical inertia and liability to breakdown. In accordance with the present invention such difficulties are avoided by the use of electronic'switching elements and a feeler which operates practically without inertia.

We claim:

1.; Control apparatus for a textile machine for processing yarn to initiate control of machine operating components in a timed sequence in response to changes in yarn tension, the improvement comprising a first textile machine operating component, pulse means operable to control said first operating component, a second textile machine operating component, delayed action timing means operable to control said second operating component, and yarn tension monitoring means for synchronously actuating independently said pulse means and said delayed action timing means.

2. The control apparatus defined in claim 1, in in which the textile machine is a spinning machine, the yarn monitoring means actuating the pulse means and the delayed action timing means in response to a decrease in yarn tension, the first operating component including yarn reserve release mechanism operated by the pulse means to release the yarn reserve, and the second operating component including sliver supply interrupting means operated by the delayed action timing means to interrupt sliver supply.

3. The apparatus defined in claim 2, in which the yarn tension monitoring means is operable in response to a subsequent increase in yam tension to prevent operation of the sliver supply interrupting means by the delayed action timing means.

4. The apparatus defined in claim 1, in which the pulse means includes a capacitor, a diode for blocking capacitor discharge and a high value discharge resistor connected in parallel with side diode, said diode and resistor being connected in series with said capacitor.

5. The apparatus defined in claim 1, in which the delayed action timing means includes a capacitor, a diode for blocking capacitor charging and a high value resistor connected in parallel with said diode, said diode and resistor being connected in series with said capacitor.

6. The apparatus defined in claim 1, a third textile machine operating component, second pulse means operable to control said third operating component, said second pulse means being connected with the delayed action timing means.

7. The apparatus defined in claim 1, a third textile machine operating component, second delayed action timing means operable to control said third operating component, said second delayed action timing means being connected with the first delayed action timing means.

8. The apparatus defined in claim 7, in which the textile machine is a spinning machine and the third operating component includes spinning chamber actuating means deactuatable by the second delayed action timing means. I

9. The apparatus defined in claim 1, in which the pulse means includes a transistor and a capacitor, voltage supply means, a supply line connected between said capacitor and the base of said transistor and connected to said voltage supply means, and manually operable switch means connected in said supply line between said voltage supply means and said capacitor for actuating the pulse means independently of the yarn tension monitoring means.

10. The apparatus defined in claim 1, the yamtension monitoring means including a switch, a supply line, a capacitor connected to the supply line, a DC circuit, a discharge circuit including a resistor, and means for connecting said capacitor selectively with the negative pole of the DC circuit or with the discharge circuit in response to opening of said switch.

11. The apparatus defined in claim 1, in which the yarn tension monitoring means includes a substantially straight spring sensor, mounting means mounting one end of said sensor for effecting a predetermined spring tension in said sensor, said sensor being movable in response to a change in yarn tension, and switch means actuating the pulse means and the delayed action timing means in response to predetermined movement of said sensor.

12. The apparatus defined in claim 11, and an adjustable screw spaced from the sensor mounting means, the sensor being engageable with said setting screw in response to changes in yarn tension, the sensor and said setting screw cooperating to form the switch means.

13. The apparatus defined in claim 11, and an adjustable screw spaced from the sensor mounting means and engageable with the sensor for adjusting the sensor tension.

14. The apparatus defined in claim 11, a contact on one side of the sensor engageable thereby to form cooperatively the switch means, and damping means on the opposite side of the sensor for damping vibration of the sensor.

15. The apparatus defined in claim 1, and control switch means operable by the yarn tension monitoring means for actuating the pulse means and the delayed being rigidly connected to said housing.

ragga v UNITED STATES PATENT OFFICE CERTIFICATE OF ORECTION Patent No. 3,803,823 Dated April 16, 1974 Inventor(s) Heinrich Niestroi Hans Landwehrkamn. Gerhard Hooher It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 13, line 65, cancel "in" (second instance) Column 14, line 16, cancel "side" and insert -said--.

Signed and? sealed this 29th day of October 1974.

.(SEAL) Attest: McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents

Claims

1. Control apparatus for a textile machine for processing yarn to initiate control of machine operating components in a timed sequence in response to changes in yarn tension, the improvement comprising a first textile machine operating component, pulse means operable to control said first operating component, a second textile machine operating component, delayed action timing means operable to control said second operating component, and yarn tension monitoring means for synchronously actuating independently said pulse means and said delayed action timing means.

3. The apparatus defined in claim 2, in which the yarn tension monitoring means is operable in response to a subsequent increase in yarn tension to prevent operation of the sliver supply interrupting means by the delayed action timing means.

8. The apparatus defined in claim 7, in which the textile machine is a spinning machine and the third operating component includes spinning chamber actuating means deactuatable by the second delayed action timing means.

10. The apparatus defined in claim 1, the yarn-tension monitoring means including a switch, a supply line, a capacitor connected to the supply line, a DC circuit, a discharge circuit including a resistor, and means for connecting said capacitor selectively with the negative pole of the DC circuit or with the discharge circuit in response to opening of said switch.

15. The apparatus defined in claim 1, and control switch means operable by the yarn tension monitoring means for actuating the pulse means and the delayed action timing means, said switch means being operable without mechanical contact.

16. The apparatus defined in claim 15, in which the control switch means is a proximity switch.

17. The apparatus defined in claim 11, and two spaced guide saddles for guiding a yarn stretch to be monitored, the sensor portion engageable with such yarn stretch being located between said spaced guide saddles.

18. The apparatus defined in claim 17, a housing for the sensor and the switch means, the guide saddles being rigidly connected to said housing.