US3522913A

US3522913A - Method for controlling a textile machine,particularly an automatic cross-winding machine,as a function of yarn travel,and apparatus for carrying out the aforesaid method

Info

Publication number: US3522913A
Application number: US760318A
Authority: US
Inventors: Hermann Werffeli
Original assignee: Machinenfabrik Schweiter AG
Current assignee: Machinenfabrik Schweiter AG
Priority date: 1967-09-26
Filing date: 1968-09-17
Publication date: 1970-08-04
Anticipated expiration: 1987-08-04
Also published as: DE1760969C3; GB1239612A; FR1577762A; DE1760969A1; CH467209A; AT291825B; BE720244A; DE1760969B2; JPS4825020B1

Description

Aug. 4, 1970 H. WERFFELI 3,522,913

METHOD FOR CONTROLLING A TEXTILE MACHINE, PARTICULARLY AN AUTOMATIC CROSS-WINDING MACHINE, As A FUNCTION OF YARN TRAVEL, AND APPARATUS FOR CARRYING OUT THE AFORESAID METHOD Filed Sept. 17, 1968 2 Sheets-Sheet 1 INVENTOR #AM4w WFFAZ/ BY 1M ATTORNEYS.

H. WERFFELI 3,522,913

PARTICULARLY AN AS A FUNCTION OF AND APPARATUS FOR CARRYING OUT THE AFORESAID METHOD Aug. 4, 1970 METHOD FOR CONTROLLING A TEXTILE MACHINE.

AUTOMATIC CROSS-WINDING MACHINE,

YARN TRAVEL,

2 Sheets-Sheet 2 Filed Sept 17. 1968 Fig. 4

INVENTOR Maui/w) hitefifzu By W t t Fig. 3

ATTORNEY5 United States Patent 01 3,522,913 METHOD FOR CONTROLLING A TEXTILE MA- CHINE, PARTICULARLY AN AUTOMATIC CROSS-WINDING MACHINE, AS A FUNCTION OF YARN TRAVEL, AND APPARATUS FOR CARRYlNG OUT THE AFORESAID METHOD Hermann Werfieli, Horgen, Switzerland, assignor to Maschinenfabrik Schweiter AG, Horgen, Switzerland, a corporation of Switzerland Filed Sept. 17, 1968, Ser. No. 760,318 Claims priority, application Switzerland, Sept. 26, 1967, 13,405/ 67 Int. Cl. B65h 63/00 US. Cl. 242-36 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for controlling a textile machine such as an automatic cross-winding machine, in dependence upon the path of travel of the yarn is disclosed. Electrical signals are produced as the yarn travels through the machine, a positive voltage peak indicating a section of enlarged yarn thickness, a negative voltage peak indicating the falling out of the yarn from its path of travel. The positive voltage peak is subsequently utilized for triggering a yarn cleaning or cutting mechanism and the negative voltage peak is subsequently utilized for triggering a bobbin exchange operation. However, when a yarn cutting or cleaning operation is being effected, the yarn necessarily would have fallen out of its path of travel, i.e. a negative voltage peak will have been generated in response thereto. Since, in this instance, a bobbin exchange operation is not desired, the subject invention provides means for suppressing or inhibiting the effect of the negative voltage peak produced during the yarn cutting or cleaning operation. Thus, in a simple, electronic fashion, the cleaning and bobbin exchange operations, necessary in textile machines, are accomplished.

BACKGROUND OF THE INVENTION The present invention relates to an improved method of and apparatus for controlling a textile machine, in particular an automatic cross-winding machine, as a function of the movement or travel of the yarn.

As is generally known, and as occurs in automatic winding machines having a plurality of winding stations or locations, the yarn at each winding location is under constant supervision so as to trigger an automatic yarn servicing mechanism, such as an automatic bobbin exchange mechanism and/or an automatic yarn knotting mechanism and the like whenever yarn defects occur, to thus remedy the defect at the particular affected winding location. In order to accomplish this purpose, so-called yarn cleaners are, on the one hand, operably associated with the yarn paths of travel and, on the other hand, drop brackets or lambellae feelers or the like are provided as monitoring elements. In this regard, the so-called yarn cleaners are capable of placing an automatic yarn knotting mechanism into operation in response to yarn defects, whereas the drop brackets or lambellae are utilized to trigger an automatic delivery bobbin exchange mechanism. It has been found, however, that drop brackets, lambellae feelers, and similar monitoring elements of mechanical configuration no longer meet modern requirements resulting from the continually increasing yarns speeds in use, in that such drop brackets, or feelers bear upon the yarn and load the same in an undesirable fashion, and furthermore, the increased inertia upon such mechanical configurations caused by continuous deposits of dirt and dust greatly inhibits an instantaneous or immediate response of the element.

In contrast with the disadvantages of the mechanical drop brackets, lambellae feelers and the like, yarn cleaners have proven to be inertia-free and maintenance free yarn monitoring elements which do not adversely affect the yarn itself. In this regard, yarn cleaners monitor or supervise the yarn within the operating region of an auto matic yarn knotting mechanism whereby the yarn pro duces an electrical signal at the path of travel thereof as defined or limited by a capacitive or photoelectric cell. The electrical signal normally is an AC. signal generated by virtue of fluctuations in the yarn diameter which are subsequently amplified and rectified, the resultant DC. signal thus obtained being evaluated as an indication of the presence of yarn moving in the prescribed path of travel. If the yarn is stopped or if the yarn is entirely absent at such prescribed path of travel, the DC. signal will thus be removed. In consequence thereto, the relevant Winding location is placed out of operation, preferably via relay arrangements or the like and the automatic yarn knotting mechanism is then actuated. On the other hand, if the yarn passing through the prescribed path of travel exhibits an impermissible enlarged or thickened location, then a so-called positive voltage peak results on the electrical signal, this positive voltage peak being utilized for triggering a yarn cutting or cleaning operation and, subsequent thereto, the winding location is made temporarily inoperative and the knotting operation initiated due to the absence of the above-described DC. signal. A yarn cleaner control as generally described above, for example, is known in the art and is depicted in detail in the commonly assigned Swiss Pat. No. 389,470.

Accordingly, the above-described yarn cleaner as utilized with the conventional variety of control techniques serves to control the textile machine as a function of the yarn condition only so long as the yarn remains in the effective or operable zone of the automatic knotting mechanism and can be seized by such knotting mechanism. On the other hand, with such conventional control techniques, if the yarn ruptures outside of this effective or operable zone or if the delivery bobbin becomes depleted, then a mechanical scanner or feeler is placed into operation and initially triggers operation of the automatic delivery bobbin-exchange mechanism.

SUMMARY OF THE INVENTION Accordingly, a primary object of the present invention relates to an improved method of and apparatus for controlling an automatic cross-winder as a function of yarn travel which serves to overcome the aforementioned drawbacks of prior-art techniques and structures.

Another significant object of the subject invention relates to an improved method of and apparatus for controlling an automatic cross-winder or the like as a function of yarn travel by employing only a yarn cleaner as the single yarn monitoring element thus eliminating the use of brackets, feelers or the like and thus eliminating the disadvantages previously described with respect to such mechanical configurations.

Still a further significant object of the present invention resides in the provision of an improved technique and apparatus for supervising yarn travel at a textile machine such as an automatic cross-winder, in a manner which not only is less likely to damage the yarn by avoiding the use of certain prior-art elements such as mechanical feelers or the like which physically contact the yarn and which were previously thought to be necessary for yarn supervisory functions, but also results in a less complicated apparatus structure which is not as subject to malfunction and which requires far less maintenance than was the case with the prior-art.

The above-defined objects as well as others which will become apparent are implemented by the subject invention in that the method thereof is characterized by the fea-- tures that the amplified signal at the output side of the yarn cleaner or measuring cell, in addition to being utilized for triggering a yarn cleaning and knotting operation, also is utilized for actuating the automatic delivery bobbin exchange mechanism and, in so doing, avoids the disadvantages of the bracket-type monitor or feeler or other mechanical devices for this purpose as discussed above. In this respect, a negative voltage peak which occurs on the electrical signal produced by yarn travel represents the falling of the yarn out of its normal path of travel and that this negative voltage is evaluated and utilized, after a threshold value is surpassed, for bringing in a new yarn, i.e. for triggering the automatic delivery bobbin exchange operation. Furthermore, a positive voltage peak appearing on the electrical signal caused by yarn passage which represents an impermissible enlargement or thickness in the yarn and which is normally utilized for triggering a yarn cleaning or cutting operation is utilized also, in accordance with the subject invention, for inhibiting or suppressing the effect of the negative voltage peak signal which causes the new yarn to be brought in. Thus, an automatic delivery bobbin exchange operation is prevented from taking place during periods of operation of the yarn cutter or cleaner.

For purposes of clarity, a positive voltage peak is to be understood to be that voltage produced during the path of travel of the yarn when the diameter of the traversing yarn changes in excess of a predetermined value.

The novel inventive method proceeds from the fact that when the yarn falls out of the measuring zone, a voltage peak also appears prior to the signal falling to a zero or rest level which likewise is indicative of no yarn movement, this voltage peak occurring in a direction opposite to the direction of the voltage peak caused as a result of enlarged yarn thickness. This signal change described as a negative voltage peak in accordance with the above definition not only appears when the yarn supply is exhausted and wherein a new yarn must subsequently be brought in, but also appears or occurs when the yarn is cut because of an area of enlarged thickness. In this latter instance, it will be appreciated that an automatic delivery bobbin exchange operation is not necessary since the yarn only needs to be re-knotted. Therefore, a feedback coupling of the signal resulting from the positive voltage peak is utilized so as to prevent the automatic delivery bobbin exchange operation during such periods.

By virtue of these inventive measures and techniques, it is now possible to effect control of a textile machine in dependency upon the path of travel of the yarn and through the use of a single supervisory monitoring member, that is, a yarn cleaner, the result being a substantially simpler and far safer and faster operation of the textile machine.

The subject invention further relates to a novel, improved apparatus for carrying out the aforesaid method, the novel apparatus having an electric feeler or sensing means, the output of which is, on the one hand, coupled with a first circuit means responsive to certain voltage conditions so as to effect a yarn cleaning or cutting operation. On the other hand, the output of the electric feeler or sensing means is further coupled with a second circuit means responsive to certain voltage conditions for stopping or turning ofi the relevant winding location. The output of the electric feeler or sensing means is connected with an additional evaluation circuit, preferably an integrator circuit, with which a further switch means is associated, the further switch means responding to certain voltage conditions for triggering the automatic delivery bobbin exchange mechanism. A switching element is disposed in the circuit of the delivery bobbin exchange mechanism switch means, the switch element, when actuated, inhibiting operation of the delivery bobbin exchange mechanism. This switch element is itse f contemplated to be actuated by the output circuit of the yarn monitoring, feeling or sensing means.

BRIEF DESCRIPTION OF THE DRAWINGS Additional advantages and features of the invention will become apparent when consideration is given the following detailed description of preferred inventive embodiments, such description making reference to the appended drawings wherein:

FIG. 1 depicts a schematic representation of a winding location of an automatic winding machine;

FIG. 2 depicts a circuit arrangement of a yarn cleaner having an evaluation circuit;

FIG. 3 is a schematic diagram of the voltage variation occurring at the output of the measuring cell of a yarn cleaner under various operational conditions and as a function of the measuring time;

FIG. 4 is an electrical circuit schematic of a control switch operable by the evaluation circuit of FIG. 2;

FIGS. 5 and 6 depict two embodiments of measuring slots found at the yarn cleaner.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1, a winding location 10 is depicted, a plurality of these locations being mounted on a rotating table of an automatic winding machine not depicted in detail in the drawings. A so-called automatic yarn knotting mechanism as well as an automatic delivery bobbin exchange mechanism are disposed, in known fashion, outside the rotary path of the winding locations 10. Each of the winding locations can be brought into operational contact with the automatic knotting mechanism and the automatic delivery bobbin exchange in known fashion. Details of a machine of the type-described are not necessary for an understanding of the subject invention, these details being well-known in the art.

A yarn P is drawn off a delivery bobbin 11 at winding location 10 and is delivered to a wind-up or take-up bobbin 17 via a balloon breaker 12, a brake 13, an electronic yarn cleaner 14, a deflecting plate 15, and a grooved drum 16. The directional movement which the yarn takes is monitored by the yarn cleaner 14 which, in dependence upon the operational condition thereof, brings winding location 10 into operational contact or association with an automatic yarn knotting mechanism and the automatic delivery bobbin exchange mechanism and further serves to trigger the action of one or the other mechanisms as is described below in greater detail.

For example, the automatic yarn knotting mechanism must be initiated into action when the yarn is ruptured in a location between the brake 13 or the yarn cleaner 14, respectively, and the winding bobbin 17 or, alternatively, if the yarn is separated or cut by the yarn cleaner 14. In both instances, the automatic yarn knotting mechanism serves to take up both ends of the yarn and knot them together such that operation of the automatic delivery bobbin exchange mechanism is prevented and the exchange of the delivery bobbin 11 itself is avoided. On the other hand, if the yarn is ruptured below the brake 13 or if the delivery bobbin 11 is depleted or empty, then prior to knotting the yarn ends together, the delivery bobbin 11 must necessarily be replaced.

FIG. 2 depicts a circuit arrangement of a yarn cleaner generally designated 14 having a suitable evaluation circuit for evaluating the occurrence of the above-mentioned disturbances and for triggering the proper disturbanceeliminating mechanism. In accordance with the representation of FIG. 2, the yarn cleaner 14 is seen to comprise a photoelectric measuring cell 18 the output of which is coupled to an amplifier 19. Amplifier 19, amongst other functions, provides a signal to a relay 21 via a threshold value circuit arrangement 20, the relay 21 being operable to actuate a yarn cutting knife 22.

A first evaluation circuit generally depicted by reference numeral 23 is coupled to the output of amplifier 19 and serves to turn off or disable the Winding location of FIG. 1. Evaluation circuit 23 is seen to comprise an amplifier 24, a rectifier 25 and a control relay 26.

As mentioned above, yarn F produces an alternating current signal in the output of the measuring cell 18 as the yarn passes measuring cell 18 by virtue of diameter variations of the yarn. The alternating current has a wave form as depicted by curve 27 of FIG. 3. The alternating current is amplified by amplifier 24 and is then rectified by rectifier 25 of the evaluation circuit 23. The output signal from rectifier 25 is normally a continuous signal which is then applied to the control relay 26. However, when the travelling yarn exhibits a point of enlarged thickness or diameter in the area of measuring cell 18, a positive voltage peak as depicted in curve 28 of FIG. 3 is produced at the output of measuring cell 18. When the yarn falls out of its normal path of travel, a negative voltage peak as depicted by curve 29 of FIG. 3 is produced by the measuring cell. Finally, in the situation wherein the yarn is missing or wherein the yarn is not moving, a zero voltage is illustrated by curve 30 of FIG. 3 is produced by the measuring cell 18. As a result of either the negative voltage peak 29 or of the zero voltage condition 30, the direct current signal at the output of rectifier 25 will be removed and thus result in a switching operation of the control relay 26 which serves to actuate the turn-off of the afiected winding location and further serves to initiate operation of the automatic knotting mechanism unless a signal is present, as will be discussed below, which gives preference to the actuation of the automatic delivery bobbin exchange operation instead.

If an enlarged thickness at the yarn occurs, the output signal from amplifier 19 will change and will take the form of the voltage impulse or positive voltage peak 28 as depicted in FIG. 3. If this voltage peak surpasses a particular predetermined threshold value of the threshold switch 20, then the relay 21 is immediately excited and triggers the cutting of the yarn by knife 22. Reference is made to curve 21' of FIG. 3 wherein the switching time of relay 21 is depicted.

As mentioned above, a voltage peak as illustrated in curve 29 of FIG. 3, that is a negative voltage peak, represents the falling of yarn F out of its normal path of travel through the measuring cell 18. The negative voltage peak of curve 29 serves the purpose of producing a signal which can be utilized for bringing in a new yarn, that is for triggering operation of the automatic delivery bobbin exchange mechanism. For this purpose, a second evaluation circuit generally designated by reference numeral 31 is provided, the second evaluation circuit 31 comprising two

inputs

32 and 33, respectively. One input 32 is connected in parallel with the output of amplifier 19 of a yarn cleaner 14 and is further connected with a first input 132 of an electronic gate or switching means 34. The other input 33 of the second evaluation circuit 31 is connected in parallel to the output side of the rectifier 24 of the first evaluation circuit 23 and is further connected to a second input 133 of the electronic gate 34 via parallely connected timing circuits t and t and a further gate or switch circuit 35 serially connected with the timing uircuits t and t An integrator 36 and a threshold value switch means 37 having a relay 38 associated with the output thereof are connected to the output of gate 34.

If the yarn F falls out of the zone of the measuring cell 18 due to a rupture occurring below the brake 13 of FIG. 1 or because of a depletion or emptying of the delivery bobbin 11, then a signal represented by curve 29 of FIG. 3 would appear at the input 132 of the gate 34. In order to open gate 34, however, a signal at input 133 must also appear. This signal will appear, however, only if timing circuit i generates a signal to gate 35. On the other hand, if a direct current signal is present at the inputs of timing circuits t and t then gate 35 is blocked. Since, however, the direct current signal is removed in the presence of the negative voltage peak 29, the result is that the timing circuits t and t are switched in a manner such that first t and then t temporarily suppress the input signal to gate 35, this operation being achieved, for example, by means of delayed-release relays. In this manner, gate 34 becomes conductive only in the period of time t -t in accordance with FIG. 3, this action overcoming the deleterious effect of any spurious disturbances in the system. Now, if the output signal from integrator 36 surpasses the particular predetermined threshold value of the theshold switch 37, relay 38 will respond and, via contact 38, would initiate the operation of the automatic delivery bobbin exchange mechanism. If, however, the yarn F is ruptured in such a manner that the yarn remains within the measuring zone, gate 34 would still receive a signal via the

inputs

132 and 133 and thus become conductive. During this operation, however, the zero signal level 30 reaches the integrator 36 via the input 132. As a result thereof, integrator 36 cannot produce an output signal which surpasses the particular threshold value of the switch 37 so that relay 38 cannot respond. Curve 38" of FIG. 3 depicts the switching time of relay 38.

As previously explained, the yarn F may fall out of the measuring zone under some conditions without making a delivery bobbin exchange operation desirable. This condition occurs if the yarn F is cut through by the yarn cleaner 14 in the above-described manner upon the appearance of an undesired point or area of thickness or enlargement in the diameter thereof. In such case, the yarn separation signal is used additionally for suppressing the signal serving to actuate the automatic delivery bobbin exchange mechanism. For this purpose, a timing circuit t is provided in parallel circuit arrangement to the relay 21 of the cutting knife 22 of yarn cleaner 14, the timing circuit opening a switch 2" in response to the yarn separation signal at time t pursuant to cover t" of FIG. 3. Time t;; as utilized herein suitably corresponds to the damping time of the negative voltage peak 29 until the occurrence of the resting or no-signal potential voltage 30.

The switch t is disposed in a control circuit as depicted in FIG. 4, switch t being in series with a switch-on relay mechanism 40 for control of the automatic delivery bobbin exchange mechanism and further is disposed in series with a switching contact 38' of relay 38 which actuates the exchange operation.

Now, if the yarn F falls outside of the zone of the measuring cell or sensing means 18 as a result of the cutting or separation thereof by the yarn cleaner 14 actuated by an impulse at the cutting relay 21, an initiating signal for the automatic delivery bobbin exchange mechanism is still given via contact 38 of relay 38. But, in this instance the initiating signal is inhibited or suppressed through the operation of contact 1 of the timing circuit t together with the separation signal since timing contact t opens as can easily be determined by FIG. 4.

It should be mentioned at this point that the scope of the invention is not limited to the switching arrangement as specifically described above. Thus, widely varying switching elements may be thought of as timing circuits t, t, and t or the feedback coupling of the signal from the outlet of the yarn cleaner to the evaluation circuit for the negative voltage peak may be effectuated without contacts in diiferent manners.

It may be mentioned further that the yarn cleaner can suitably be provided with a slot cover so as to prevent the yarn from jumping out of the measuring slot of the yarn cleaner inasmuch as the pre-tension produced as a result of the formerly used drop bracket type monitors or lamellae feelers is absent at the yarn in the subject inventive arrangement.

Pursuant to FIG. 5, this slot cover can be a slide member 50 at the front end of the yarn cleaner 14, the slide member being kept in closed position against the efiect of a spring 52 by an electromagnet 51. The electromagnet 51 is excited for the purpose of emplacing yarn F as a result of which the closure position is opened.

According to FIG. 6, the slot cover is seen to comprise a flap member 53 which may be tilted inwardly for the purpose of inserting yarn F into the measuring slot of yarn cleaner 14.

It should be apparent that the objects set forth at the outset of this specification have now been successfully achieved accordingly, what is claimed is:

What is claimed is:

1. In a method for controlling a textile machine such as an automatic cross-winding machine in dependency upon the traversing yarn wherein the yarn is monitored during its path of travel through the machine and wherein an A.C. electrical signal is produced representing diameter variations of the yarn, the A.C. signal being amplified and rectified, the resultant DC. signal being indicative of yarn presence, and wherein a positive voltage peak of the electrical signal representative of points of enlarged yarn thickness is utilized after surpassing a threshold value for cutting the yarn, the improvement which comprises the further steps of exchanging the yarn delivery bobbin in response to a negative voltage peak of the electrical signal after a threshold value has been exceeded, the negative voltage peak representing the falling of the yarn out of its normal path of travel; and inhibiting the delivery bobbin exchange operation in response to the presence of a prior positive voltage peak which has initiated a yarn cutting operation.

2. The improvement as defined in claim 1 wherein the exchange operation is responsive to an integration of the negative voltage peak as a function of time.

3. An apparatus for controlling a textile machine such as an automatic cross-winding machine in dependency upon the traversing yarn, said apparatus comprising: electrical sensing means having an output for monitoring the yarn and for producing an electric signal in response thereto; yarn cutting means for cutting the yarn; first cir cuit means coupled to said output of said electrical sensing means and responsive to a first voltage condition, said first circuit means including a switch member to actuate said yarn cutting means; second circuit means coupled to said output of said electrical sensing means and responsive to a second voltage condition to render inoperable a given winding location; third circuit means coupled to said output of said electrical sensing means and responsive to a third voltage condition, said third circuit means including a switch member for actuating a yarn delivery bobbin exchange operation; and switch means coupled with said first and third circuit means for inhibiting actuation of the yarn delivery bobbin exchange operation upon actuation of said yarn cutting means.

4. Apparatus as defined in claim 3 wherein said switch member of said third circuit means includes a switching circuit for the actuation of said yarn delivery bobbin exchange operation, and wherein said switch means coupled with said first and third circuit means includes a switch member disposed in said switching circuit of said switch member of said third circuit means and responsive to operation of said switch member of said first circuit means to inhibit operation of said switching circuit.

5. Apparatus as defined in claim 4, wherein said third circuit means includes an integrating circuit for integrating the voltage from said output of said electrical sensing means as a function of time, and wherein said second circuit means includes a rectifier for rectifying the voltage from said output of said electrical sensing means.

6. Apparatus as defined in claim 5, further including a first gate means having first and second inputs, and an output coupled with said integrating circuit, said first input "being coupled with said output of said electrical sensing means, said second input being coupled with an output of said rectifier by coupling means.

7. Apparatus as defined in claim 6, wherein said coupling means between said rectifier and said second input of said first gate means comprises a time limiting circuit means.

'8. Apparatus as defined in claim 7, wherein said time limiting circuit means comprises a second gate means having first and second inputs, and an output coupled to said second input of said first gate means, two parallel connected timing circuits coupled between said rectifier and said respective first and second inputs of said second gate means.

9. Apparatus as defined in claim 5, wherein said switch member of said switch means disposed in said switching circuit of said switch member of said third circuit means and responsive to operation of said switch member of said first circuit means comprises an electrical contact, said switch means comprising a further timing circuit means disposed parallel to said switch member of said first circuit means for operating said electrical contact.

10. Apparatus as defined in claim 9, wherein said switching circuit of said switch member of said third circuit means comprises a series circuit connection of an electrical contact operated by a relay in the output of said third circuit means, said electrical contact of said switch means, and a switching relay for actuating said yarn delivery bobbin exchange operation.

References Cited UNITED STATES PATENTS JOHN PETRAKES, Primary Examiner