US3739996A

US3739996A - Measuring apparatus of total yarn length wound in package on a yarn winder

Info

Publication number: US3739996A
Application number: US00157935A
Authority: US
Inventors: I Matsui; Y Ueda
Original assignee: Murata Machinery Ltd
Current assignee: Murata Machinery Ltd
Priority date: 1971-06-29
Filing date: 1971-06-29
Publication date: 1973-06-19
Anticipated expiration: 1990-06-19

Abstract

A measuring apparatus of total yarn length wound in package form on a yarn winder including an electric circuit for prescribedly delaying emission of pulses, which correspond to each cycle rotation of a yarn traversing drum rotationally carrying a growing package in contact thereon for winding rotation or its drive motor, to a counter part of the emitted pulses from starting of winding operation.

Description

United States Patent Mat sui et al.

MEASURING APPARATUS OF TOTAL YARN LENGTH WOUND IN PACKAGE ON A YARN WINDER Inventors: Isamu Matsui, Kyoto; Yutaka Ueda,

. Nara, both of Japan Murata Machinery Ltd., Kyoto, Japan Filed: June 29, 1971 Appl. No.: 157,935

Assignee:

US. Cl 242/39, 242/30, 242/36 Int. Cl B65h 61/00, B65h 63/08 Field of Search 242/36, 39, 30, 57,

References Cited UNITED STATES PATENTS 9/1946 Seher 242/39 X 2/1959 Geitenbeek 242/39 1 June 19, 1973 2,969,197 1/1961 Weber et al. 242/39 x 3,251,562 5/1966 Petersen 242/39 3,648,027 5/1972 Ganong et al. 242/36 x FOREIGN PATENTS OR APPLICATIONS 737,687 9/1955 Great Britain 242/39 Primary Examiner-Stanley N. Gilreath Assistant Examiner-Milton S. Gerstein Attorney-Robert E. Burns and Emmanuel .l. Lobato [57] ABSTRACT A measuring apparatus of total yarn length wound in package form on a yarn winder including an electric circuit for prescribedly delaying emission of pulses, which correspond to each cycle rotation of a yarn traversing drum rotationally carrying a growing package in contact thereon for winding rotation or its drive mo tor, to a counter part of the emitted pulses from starting of winding operation.

8 Claims, 5 Drawing Figures PArsunu vm 3.139.996

FREQUENCY CONVERT E MEASURING APPARATUS OF TOTAL YARN LENGTH WOUND IN PACKAGE ON A YARN WINDER The present invention relates to a measuring apparatus of total yarn length wound on a yarn winder, more particularly relates to an apparatus for measuring the total length of a yarn wound onto a package with considerably reduced measuring error on a yarn winder whereon the yarn is wound onto the package through rotational pressure contact of the package with a yarn traversing drum.

Various systems have been developed for measurement of the total length of the yarn which has been wound on the package on the yarn winder of the abovedescribed type. In one system, the total yarn winding length is estimated on the basis of the number of cops wherefrom the yarn is delivered and wound onto the package. This estimation can be carried out with small error in the estimation when there is very small fluctuation in the length of yarns wound on the supply cops. However, in the actual mill process, it is quite usual that the wound yarn length varies considerably from cop to cop and such variation in the yarn length tends to result considerably increased error in the estimation when the estimation is based on the number of cops consumed for building of a complete package.

In another system, the total yarn winding length is estimated on the basis of the diameter of the wound-up package. When the yarn is wound onto the package with constant yarn tension throughout the growth of the package and the complete package is internally uniform as to the yarn density, this estimation can be carried out with small error in the estimation. However, in the actual process, it is almost impossible to maintain the yarn tension constant throughout the growth of the package. Fluctuation in the processing yarn tension naturally lowers the uniformity of the complete package regarding its yarn density. This results in production of enlarged error in the estimation work.

It is empirically known that, in the case of the abovementioned conventional measuring systems, the error in the estimation amounts from 5 to 6 percent of the initially designed total yarn length per a complete package.

When the point of view is changed, the take-up speed of the processing yarn is determined by the peripheral speed of the growing package. So, it may be possible to estimate the total wound yarn length on the basis of the total number of rotation of the package counted for building of a complete package. Further, because the growing package rotates due to a frictional pressure contact with a yarn traversing drum, the total rotation number of the package can be estimated on the basis of the number of rotation of the yarn traversing drum counted for building of the complete package. The yarn traversing drum is connected to a drive motor for rotation thereof. So, it may be also possible to estimate the total rotation number of the yarn traversing drum on the basis of the number of rotation of the drive motor counted for building of the complete package. In conclusion, the total wound yarn length of the complete package can be indirectly estimated on the basis of measurement of the total rotation number of the yarn traversing drum or the drive motor which is needed for building of the complete package. The basic concept of the present invention is related to the above-described idea.

However, when the above-described measuring system is employed, the following drawbacks must be considered carefully.

Firstly, when the total rotation number of the drive motor is to be measured, it must be assumed that the rotation of the yarn traversing drum exactly follows the rotation of the drive motor. Otherwise, difference in the rotation between the yarn traversing drum and the drive motor will result corresponding error in the estimation of the total yarn length on the complete package. However, it often takes place that load of the growing package on the yarn traversing motor causes mechanical slippage or the like troubles in the mechanical connection between the yarn traversing drum and the drive motor. This naturally produces the abovementioned difference in the rotation and the estimation cannot be free from error.

Secondly, when the total rotation number of the yarn traversing drum is to be directly measured, the possible mechanical slippage in the connection between the yarn traversing drum and the drive motor falls out of question. Therefore, this system may be free from the error in the estimation, if the rotation of the growing package exactly follows the rotation of the yarn traversing drum. But, it is also empirically known that the rotational contact of the growing package with the yarn traversing drum cannot be free from slippage between the two. For example, at the commencement of the winding operation, the start of the package rotation cannot follow the start of the drum rotation. Especially when the yarn is broken during the winding operation and the winding operation must be restarted after yarn piecing, the increased mass of the package hinders smooth and instant follow-up of the package rotation to the drum rotation. Poor follow-up of this kind naturally causes production of error in the estimation.

In view of the above-mentioned drawbacks, the principal object of the present invention isto provide a measuring apparatus for estimating total yarn length of a complete package on the basis of measurement of the total number of rotation of the yarn traversing drum or its drive motor with reduced error in such estimation system.

The above-described object is attained by the measuring apparatus of the present invention wherein total rotation number of the yarn traversing drum or its drive motor is measured by counting pulses corresponding to each rotational cycle for estimation of the total yarn length wound on a complete package and emission of the pulses to the counter part is commenced at a moment prescribedly delayed from "the start of the winding operation.

Through employment of the measuring apparatus of the present invention, it was empirically confirmed that the error in the estimation can be reduced down to l to 2 percent of the initially designed total yarn length per a complete package.

Further features and advantages of the present invention will be described in more detail in the following description, reference being made to the accompanying drawings; wherein FIG. 1 is a front view of a yarn winder to which the measuring apparatus of the present invention is to be attached,

FIG. 2 is a graphical drawing for showing time sequential change of the rotation numbers of elements in the first embodiment of the measuring apparatus of the present invention,

FIG. 3 is a circuit diagram for the embodiment of FIG. 2,

FIG. 4 is a graphical drawing for the second embodiment of the measuring apparatus of the present invention,

FIG. 5 is a circuit diagram for the embodiment of FIG. 4.

Referring to FIG. 1, there is shown an example of the yarn winder to which the measuring apparatus of the present invention is attached. In the shown arrangement, a yarn l is advanced from a supply cop to a growing package 3 via a yarn breakage feeler 4 as in the ordinary yarn winder. The growing package 3 rotationally rests on a yarn traversing drum 6 having a yarn guide groove or grooves. A central supporter of the package 3 is upheld by a cradle 7, which is slidably mounted to an upright rod 8 secured to a stationary framework of the yarn winder. With growth of the package 3, the cradle 7 slides upward along the upright rod 8. An arm 9 is fixed to the body of the cradle 7 with its free end being connected to a later described variable resistor (not shown in this drawing) contained in a casing 11 via a suitable connector 12 such as a wire. The yarn traversing drum 6 is rotated by a drive motor not shown in this drawing.

The theoretical background for the first embodiment of the present invention, wherein the rotation of the drive motor is measured, will now be explained in reference to FIG. 2. In the illustrated rectangular coordinate axial graph, time t after the nominal start of the winding operation, that is the start of the drive motor, is taken on the abscissa while momentary number of rotation N of rotating members such as the drive motor is taken on the ordinate. It will be well understood that the time-sequential change of the rotation number of the drive motor is represented by a straight line H; because the drive motor is supposed to run at a constant speed. As mentioned already, actual rotation of the package 3 cannot follow-up that of the drive motor for a certain length of time, the time-sequential change of the actual rotation number of the package is represented by a curve OCB.

From the drawing, it will be mathematically understood that total rotation number of an element at a selected moment is given in the form of the time integral of momentary rotation number from start to the selected time. Therefore, supposing T in the drawing as the selected moment, the total rotation number of the drive motor is given by the area OABT while that of the package is by the area OCBT. When the total rotation number of the drive motor is used for estimation of the actual total rotation number of the package 3, an estimation error represent by the area OAC will result. The situation such as shown in FIG. 2 takes place not only at the initial start of the winding operation but at the possible interception of the winding operation by, for example, yarn breakages and supply yarn consumption.

In the measuring system of the present embodiment, the measurement of the rotation number of the drive motor is commenced at the moment T. Then, the total rotation number of the drive motor at the moment T is represented by the area TDBT, which is smaller than the actual total rotation number of the drive motor represented by the area OABT. This difference is equal to the area OADT'. By this delayed measurement system, the total rotation number of the package 3 represented by the shaded area OET' is disregarded but such disregarded area OET is offset by the other shaded area EDC, which is included in the measured area TDBT. Therefore, if the moment T is adequately se lected, the delayed commencement of the measurement can advantageously exclude the estimation error caused by the delayed acceleration of the package rotation. The basic principle of the present embodiment is based on the above-explained concept of the delayed measurement.

Referring to FIG. 3, an electric circuit for practicing the above-described delayed measurement is shown. In this circuit, a drive motor 13 is provided with a pulse forming network 14 for emitting prescribed number of pulses per each rotation cycle of the drive motor 13. The pulse forming network 14 includes a frequency converter 16, two relay contacts 17a and 17b, a contact 184 of a delay relay (hereinafter referred to as the delay contact 18a), a condenser 19 and a pulse motor 21 for generating pulses according to the prescribed schedule. The pulses generated by the pulse motor 21 is accepted by a counter 22 for integration.

. The counter 22 is related to a self-holding circuit 23, which includes a contact switch 24 (hereinafter referred to as the counter contact 24) to be operated by the counter 22, a fceler contact 26 to be opened upon absence of the yarn l, a self-holding relay 17, a relay contact l7cand a push button switch 27 connected in parallel to a series circuit of the counter contact 24 and the feeler contact 26.

The self-holding circuit 23 is accompanied with a delay circuit 28, which includes a rectifier 29, a variable resistor 31 operated by the displacement of the arm 9 in FIG. 1 with growth of the package 3, a relay contact 17d of the self-holding relay 17, a resistor 32, a condenser 33 and a delay relay 18 operative on the delay contact 18a in the pulse forming network 14 and connected in parallel to the condenser 33.

The measuring apparatus having the above-described structure operates in the following manner.

At the initial starting of the winding operation, the push button switch 27 is manually pushed and the switch 27 closes temporarily. By this temporary closing of the switch 27, current flows through the coil of the self-holding relay l7 and the relay contact 17c is closed. As the two contacts 24 and 26 are already in closed condition at this stage, the self-holding circuit 23 becomes in self held disposition. Further, the

relay contacts

17a, 17b and 17d are closed due to the current flowing through the coil of the self-holding relay 17.

Under this situation, the feeler contact 26 is kept in a closed condition so long as the feeler 4 in FIG. 1 senses the presence of the running yarn 1. Concurrently with the closing of the self-holding circuit 23, the drive motor 13 commences its rotation but the pulse motor 21 generates no corresponding pulses because the delay contact 18a is not yet closed. After a time delay of prescribed length, the delay relay 18 functions to close the delay contact 18a and the pulse motor 21 starts to generate the corresponding pulses. It will be understood that this start of the pulse motor 21 takes place at the moment T in FIG. 2. The length of the delay time is controlled by the variable resistor 31 which changes time-constant determined by the values of the

resistors

31, 32 and the condenser 33 (capacitor) following the growth of the package.

Upon breakage or consumption of the yarn 1, the absence of the yarn 1 is sensed by the feeler 4 in FIG. 1 and the feeler contact 26 in FIG. 3 is opened. Upon this opening of the feeler contact 26, the self-holding circuit 23 is opened and the drive motor 13 ceases its running. After completion of the yarn piecing, the switch 27 is manually closed and the above-explained process is repeated in a similar sequence and fashion.

When the prescribed number of total rotation is counted by the counter 22, all the elements resume their initial condition so as to perform the next cycle winding operation.

The theoretical background for the second embodiment of the present invention, wherein the rotation of the yarn traversing drum 6 is directly measured, will now be explained in reference to FIG. 4, wherein a rotation number-time graph is illustrated in a manner similar as in FIG. 2. In the drawing, a straight line AT is for the drive motor rotation, a curve OCB is for the yarn traversing drum rotation and a curve OC"B is for the package rotation. The difference in the total rotation number at the moment T between the yarn traversing drum 6 and the package 3 corresponds to the area OC'C". This difference, i.e., the estimation error, is caused by possible slippage in the rotational contact of the package 3 with the yarn traversing drum 6 (see FIG. 1). This estimation error can be considerably reduced if the measurement is commenced at the moment T", i.e. the area E"E'C'C" offsets the area OE"T. The basic principle of the present embodiment is based on this concept of the delayed measure ment.

Referring to FIG. 5, an electric circuit for practicing such delayed measurement is shown. In the illustration, elements common to the foregoing embodiment and the present embodiment are indicated by similar reference numerals. Arrangements of the self-holding and the

delay circuits

23 and 28 are the same with ones employed in the first embodiment whereas that of the pulse-forming network 34 is somewhat different from the one employed in the first embodiment.

In the present embodiment, rotation number of the yarn traversing drum 6 must be measured directly. For this measurement, a pulse generator 36 is provided in relation to the rotational shaft of the drum 6 and is connected to the counter 22 via the delay contact 18a which is to be operated by delay relay 18 in the delay circuit 28.

Operational mode of this embodiment is basically similar to that of the first embodiment. Until the delay contact 18a is closed at the moment T" in FIG. 4, the pulses generated by the pulse generator 36 are not given to the counter 22. At the moment T", the delay relay 18 functions to close the delay contact 18a and the counter 22 commences counting of the given pulses for the estimation of the total rotation number.

What is claimed is:

1. A measuring apparatus for measuring the total length of yarn wound into a package on a yarn winder comprising, in combination, a pulse-forming network including a drive motor of a yarn traversing drum rotationally carrying a growing package during use of the apparatus and generating pulses at each cycle of rotation of said drive motor, a counter connected to said pulse-forming network for counting pulses from said pulse-forming network, a self-holding circuit connected to said counter operative to keep said drive motor in running condition during growth of said package, and means including a delay circuit cooperative with said self-holding circuit for placing said pulse forming network in operation at a moment T which is prescribedly delayed from commencement of rotation of said drive motor. I

2. A measuring apparatus as claimed in claim 1, wherein said pulse-forming network includes said drive motor, a frequency converter connected to said drive motor, two relay contacts inserted between said drive motor and said frequency converter and operated by said self-holding circuit, a pulse motor connected to said counter and a delay contact inserted in a circuit connecting said drive motor with said pulse motor and operated by said delay circuit.

3. A measuring apparatus as claimed in claim 1, wherein said self-holding circuit includes a counter contact connected to said counter, a feeler contact to be closed at absence of yarn, a self-holding relay, a relay contact operated by said self-holding relay and a push button switch connected in parallel to a series circuit which contains said counter contact, said feeler contact and said relay contact.

4. A measuring apparatus as claimed in claim 1, wherein said delay circuit includes a delay relay, operative on said pulse-forming network, a condenser connected in parallel to said delay relay, a resistor, a relay contact operated by said self-holding circuit, a variable resistor operated by an arm movable in proportion to said growth of said package and a rectifier connected to said variable resistor.

5. A measuring apparatus for measuring the total length of yarn wound into a package on a yarn winder comprising, in combination, a pulse-forming network including a yarn traversing drum. rotationally carrying a growing package during use of the apparatus and generating pulses at each cycle of rotation of said drive motor, a counter connected to said pulse-forming network for counting pulses from said pulse-forming network, a self-holding circuit connected to said counter operative to keep said drive motor in running condition during growth of said package, and means including a delay circuit cooperative with said self-holding circuit for placing said pulse-forming network in operation at a moment T which is prescribedly delayed from commencement of rotation of said drive motor.

6. A measuring apparatus as claimed in claim 5, wherein said pulse-forming network includes a pulse generator arranged relative to a rotational shaft of said yarn traversing drum, and a delay contact inserted between said pulse generator and said counter and operated by said delay circuit.

7. A measuring apparatus as claimed in claim 5, wherein said self-holding circuit includes a counter contact connected to said counter, a feeler contact to be closed at absence of yarn, a self-holding relay, a relay contact operated by said self-holding relay and a push button switch connected in parallel to a series circuit which contains said counter contact, said feeler contact and said relay contact.

8. A measuring apparatus as claimed in claim 5, wherein said delay circuit includes a delay relay operative on said pulse-forming network, a condenser connected in parallel to said delay relay, a resistor, a relay contact operated by said self-holding circuit, a variable resistor operated by an arm movable in proportion to said growth of said package and a rectifier connected to said variable resistor.

* II 4 t I were starts errant orrict @iiltllltltilt (it tdEtTlGN Patent No. 3 739;; 996 Dated June 19, 1973 Inventor(s) rennin narsur and rurrra urea It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Patent claims 1. and 5 should read as follows:

10 A measuring apparatus of total yarn length wound in a package on a. yarn. winder comprising in combination, a pulseforming network including a drive motor for generating pulses at each cycle of rotation. of said drive motor," a yarn traversing drum driven. by said motor and rotationally carrying a growing package a counter connected to said pulse forming network for counting pulses from said pu.lse-=;Eorming network, a self-holding circuit connected to said counter and keeping said drive motor in running condition during growth of said package, and a delay circuit arranged in combination with said selfholding circuit and placing said pulse forming network in operation at a moment '1 which is prescribedly delayed from commencement of rotation. of said drive motor. y

5.. A measuring apparatus of total yarn length wound in a package on a yarn winder comprising in combination, a drive motor, a pulse forming network including a yarn traversing drum rotationally driven by said motor lor rotationally carrying a growing package and for generating pulses at each cycle of rotation ofsaid yarn traversing drum, a counter connected to said pulse-orming network for counting pulses from said pulseforming networlw a selt' holding circuit connected to said counter and keeping said drive motor in; running condition during growth of said package and a delay circuit arranged in combination with said self holding circuit and placing said pulseforming network operation at a moment T which is prescribedly delayed from commencement of rotation of said drive motor.

Signed and sealed this 12th day of March 1974 (SEAL) Attest: v

EDWARD M.FLETCHER,JR.. V I i C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM F'O-IOSO (10-69) uscoMM-oc 6D376-P69 r U.S. GOVERNMENT PRINTING OFFICE: 1969 0-8664 5

Claims

1. A measuring apparatus for measuring the total length of yarn wound into a package on a yarn winder comprising, in combination, a pulse-forming network including a drive motor of a yarn traversing drum rotationally carrying a growing package during use of the apparatus and generating pulses at each cycle of rotation of said drive motor, a counter connected to said pulseforming network for counting pulses from said pulse-forming network, a self-holding circuit connected to said counter operative to keep said drive motor in running condition during growth of said package, and means including a delay circuit cooperative with said self-holding circuit for placing said pulse-forming network in operation at a moment T which is prescribedly delayed from commencement of rotation of said drive motor.

4. A measuring apparatus as claimed in claim 1, wherein said delay circuit includes a delay relay operative on said pulse-forming network, a condenser connected in parallel to said delay relay, a resistor, a relay contact operated by said self-holding circuit, a variable resistor operated by an arm movable in proportion to said growth of said package and a rectifier connected to said variable resistor.

5. A measuring apparatus for measuring the total length of yarn wound into a package on a yarn winder comprising, in combination, a pulse-forming network including a yarn traversing drum rotationally carrying a growing package during use of the apparatus and genErating pulses at each cycle of rotation of said drive motor, a counter connected to said pulse-forming network for counting pulses from said pulse-forming network, a self-holding circuit connected to said counter operative to keep said drive motor in running condition during growth of said package, and means including a delay circuit cooperative with said self-holding circuit for placing said pulse-forming network in operation at a moment T which is prescribedly delayed from commencement of rotation of said drive motor.