US2804744A - Supervision and control of textile manufacturing processes - Google Patents

Description

Sept. 3, 1957 E. BREUNING 2,804,744

UPERVISION AND CONTROL OF TEXTILE MANUFACTURING PROCESSES iled Nov. 10, 1952 lNmcA'rmc OR. con-ram. WENT DEVICE souacs 1n 2 INVENTOR j ERNST BREUN/NG E ATTORNEYS I SUPERVISIQN AND CONTROL OF TEXTILE MANUFACTURENG PROCESES Ernst Breuning, Stuttgart, Germany Application November 10, 1952, Serial No. 319,707

Claims priority, application Germany November 19, 1951 8 Claims. (CI. 57-81) This invention relates to improvements in the supervision and control of textile manufacturing processes.

In many textile manufacturing processes, even when using the most modern machines, a continuous supervision and control of the process is indispensable.

Thus, for example, in a cotton spinning mill many operations require this supervision. In the so-called drawing frames where the sliver is drawn through several pairs of rolls rotating at difierent speeds in order to equalize the cross-section of the sliver and pull all the top fibers straight, devices have been in use for a long time which will automatically shut the machine down in case of a breaking of the sliver. These conventional devices were always of either a mechanical or electrical nature. When of an electrical nature, the cotton of the sliver would act as a current interrupter to set the shut-off device in operation.

In the roving process, which is carried out by means of the so-called fiyer, there is eifected a continuous drawing of the sliver and a slight twist of the roving which is wound on a bobbin. Both on the path from the cans to the drawing rolls and between the drawing rolls and the spindles a breaking of the sliver or roving easily occurs. Inasmuch as such a break will disturb the course of the entire operation of the machine to an extremely great extent, the operation of the machine must be carefully watched, particularly with regard to sliver or roving breaks.

In order to remedy this drawback, there have been proposed mechanical and electrical control devices. These devices, however, have the great drawback that the sliver or roving is always mechanically stressed or contacted by the control device. In the mechanical control devices, in principle, a movable feeler is controlled by the sliver, the movement of the feeler being utilized for the mechanical actuation of control members connected therewith. In the known electrical control devices, contact between a pair of electric contacts is mechanically prevented and controlled by the sliver. In this connection, devices have become known in which the sliver is passed directly between the contact surfaces as an insulating intermediate body under the pressure of the contact members which may be developed in the form of contact rolls. There are also known contact members which are developed, for example, as rings, which contact an opposite contact by action of their weight as soon as they are no longer held by the sliver passed below them.

There is characteristic of this prior art on the one hand with mechanical devices, the continuous mechanical strain of the sliver and on the other hand with the electrical control devices the utilization of the insulating properties of the material to prevent current passage.

There are, furthermore, known devices in connection with which the sliver is supervised by means of photoelectric cells. In these devices, to be sure, the sliver is not mechanically loaded, but substantial other disadvantages exist. Aside from the break down sensitivity of such devices, they are very prone to failure due to dirt atent ice A and, therefore, require continuous attendance. Furthermore, special measures are necessary in order to exclude the eifect of daylight or artificial illumination. Finally, these devices are relatively expensive.

It has also been proposed to utilize the possibly varying resistance of a continuously moving textile sliver to supervise and/ or control the textile production.

In these known processes, the textile sliver is controlled with regard to any differences in resistance which may occur by being passed between two contact devices as, for example, rollers which are connected in the circuit of one part of a Wheatstone bridge and the current variations brought about by the variations in resistance are used to control the textile manufacturing process.

This method fails in very many cases inasmuch as many materials cannot be subjected to a mechanical contact pressure or else the arrangement of contact devices onthe prescribed path of the material makes the operating of the machine difficult.

One object of this invention is to overcome the above mentioned disadvantages and efiect the supervision and control of textile manufacturing processes without any contacting of the material such 'as the sliver or roving during normal operations. This and still further objects will become apparent from the following description read in conjunction with the drawing, in which:

Fig. 1 diagrammatically shows an embodiment of an apparatus in accordance with the invention for indicating breaks in a roving or the moving of the roving out of a predetermined path of travel.

Fig. 2 diagrammatically shows an embodiment or an arrangement in accordance with the invention for operating a control device.

In accordance with the invention, in direct contrast to the prior known electrical control devices and methods, the material is not used as an insulator between electrodes or for continuously passing current between contact electrodes, but is used as a conductor to close a normally open circuit.

In accordance with the invention, as long as the material such as the sliver or roving moves along its normal predetermined path, it will not contact an electrode or any other contact member. The electrode contact member in accordance with the invention is positioned at the limits of this normal path so that the material, such as the sliver or roving will come in contact therewith when the same breaks or passes out of the predetermined path. This contacting will then serve to close a normally open circuit which has a source of current and the source of current will pass through the circuit and may be utilized to give an electrical indication or for control actuation.

It, therefore follows, that in accordance with the invention, the material is not contacted or influenced in any way during normal operation and the contacting with the electrode or contact member only occurs when the normal operation is interrupted, i. e. when the material passes out of the predetermined or desired spacial limits or breaks.

Thus, for example, a source of current may lead through an indicating device to a contact member positioned below a roving or sliver. As this is an open circuit, no current will pass. When the sliver or roving breaks or becomes too loose it will contact the contact member. The sliver or roving must be connected to ground, as for example, by means of a machine through which it passes or by means of another grounded member which it will contact when breaking or passing out of the desired path. In the same manner, the sliver or roving may be connected to a lead which leads back to complete the circuit. When the sliver or roving contacts the contacting member, the circuit is completed by the current passing through the sliver or roving through ground or through the re- 3 turn circuit. The current thus passing will actuate the indicating device such as a light, hell or the like. The place of the indicating device is, of course, possible to have a control actuation device for shutting ,down the machine or the like.

Ina-series of investigations it was-found that the electric resistances of cotton, staple fiber or wool at the custornary sliver roving "or yarn cross-sections amount to about 10 ohms/cm. -length. By utilizing electric indicating and/or relay means which have an electrical internal resistance which is at least of the same order of magnitude as that indicated above, it is possible to utilize the electric currents brought about by the materials to be worked, particularly when using relatively high operating voltages, to supervise the material "being worked. If, for instance, a cotton sliver is passed over or between two contact electrodes which are insulated from'each other,-and.spaced lcm'apart'in such a manner that the sliver touches them, an operating voltage of 1090 volts-applied to the contactelectrodes brings about a current of about l lamperes through the sliver and electrodes. This current can readily be used for indicating and control purposes.

'In accordance with the present invention, it is possible to maintain the material within a desired path of travel by positioning contact electrodes so that the material only comes into galvanic contact therewith or acts capacitatively thereon when the material leaves the desired path. This contacting of the material with the contact electrodes serves to'clos'e the open circuit with the use of the material itself asthe conductor. The closing of the circuit allows the passage of current from a continuously available current source which inturn effects indication or control actuation.

In this manner, it is possible in accordance with the present invention to supervise the material without any mechanical contact aslongas the operation is carried out without defect.

itis apparent that the invention-is not only applicable for electrically supervising textile manufacturing processes and maybe used for the supervision and control of other similar processes.

In Fig. l the roving 1 moves in aiiyer from the drawing rolls '2- and 3 to the spindle 4. Directly below the path of the roving at a distance of a few centimeters from the axes of the drawing-roll and parallel to same there is arranged aconductive body 5 supported on highquality insulators 6. Theconductive body 5 is connected by a wire 7 with the electric observation or control instrumcnt'S. The instrument =8 has .a hi'girq-uality duct insulator 9, an indicator instrument 10 0f known design and a ground connection 1-1. As soon as the roving 1, due to a break leaves its normal path, it contacts the conductive body 5 and thus biingsabout an electric connection between the wire 7 and the grounded drawing rolls 2 and 3. Due to thiscurrent, an indication will flow through the indicator; the body 5; the roving'l; rolls 2 and 3 to ground, thus causing an indication on'the indicator E0 of the instruments. In order to increase the indication sensitivity or speed, aconductive grounded body 12 can be provided below the roving 1 at a distance of a few centimeters from same, said body considerably shortening the current path through the overlying part of the roving.

In Fig. 2 there is shown an arrangement which opcrates not only as indicating apparatus but also as control apparatus. 'In'this connection, an electrostatic relay is used. The wire 7 is connected with the high-quality insulated conductive stationary-body 16; opposite it, the conductive'body 17 is movablyarra'nged, said body being able to move towards 'the body '16 around a supporting point 18. At thefree end of the body '17 there-is a contact 1i9 which is opposite 'a stationary,preferably adjustable conta'cfi-ZO. -As soon as a voltage drop-takes place on fthe high ohrnic i esistance 14, the body 17 is electrostatically attracted by body 16. In this way, contacts 19 and 20 come into contact with each other. A source of current 21 which is conductively connected on the one hand with the body 17 via the pin 18 and on the other hand with an electrostatic indicating or control device 22 brings about in this case an actuating current in apparatus 22.

The speed of response of the supervisory or control apparatus can, in accordance with a further feature of the invention, ee brought to a desired amount in the manner that the electric time constant which is determined essentially "by the capacitance of the contact electrode, the connecting line of same to the indicating or control apparatus and the electrometer arrangement and also by the resistance or the material and of the high ohmic resistance is brought to the desired value by suitable dimensioning of the measuring length of the material and/or suitable dimensioning of the high ohmic resistance and/or by the connection of high quality insulated condenser.

In accordance with a'further feature of the invention, the contact electrode can be developed as a hollow body and'provided with gas passage openings. In that way, it is possible by using gas under pressure to prevent the depositing of particles of material on the contact electrode or when using suction to draw the particles of material otf above the contact electrode.

Instead of elcctrornete'r arrangements, there can be used in accordance with a further feature of the invention an electron tube having a high input resistance. Known bridge circuits c'analso be used.

In order to keep'the necessary equipment at a minimum, itis advisableinacco'rdance with a further feature of the invention in case of simultaneous supervision of a'plurality of similaror different processes to use the high voltage genera-tor 'and/ or the clectrometer arrangement and/or the contact electrodes and/or connected control devices jointly in a manner known for a plurality of observation and/or control stations.

The term control supervision, as used in this applica-tion 'isi'ntended to designate use of the current for at least one of-electrical indication and of control actuation.

Iclaim:

1. In a method for electrically supervising textile manufacturing'processes' in which a continuously moving length of textile material which has not been pretreated for increasing the electrical conductance thereof is passed "along a-predetermined path'of travel, the improvement which comprises maintaining an electrical contact out of said predetermined path positioned for con tact with'said textile material passing out of said predetermined path, 'maintaining a continuously available source of current .tosaid contact to form an open circuit to be'close'd through said textile material uponcontact thereof withsaid contact said source of current being of sufiicient voltage to flow through said textile material upon the closing of said circuit thereby, and utilizing current-passing throughsaid circuit when closed for control supervision.

2. Improvement according to claim 1 in which an electrical contact .is maintained below said predetermined path for contact'with said textile material upon breaking thereof. 7

3.. Improvement-according to claim 1 in which said textile .material is connected to ground and in which said open circuit -is closed :upon'contact of said textile material with said contact forming 'an electrical connection tosground.

4.4Apparatus f0r the'supervision of textile manufacturing 'processes in whicha continuously moving length often-tile material which has not been pretreated for increasing the-electrical conductance thereof is passed along a"predetennined path oftravehcomprising electrical contact means, a continuous current source of sufiicient volttage to pass through textile material which has not been treated for increasing the electrical conductance thereof, an open circuit from said continuous .current source terminating at said electrical contact means said contact means being positioned outside said predetermined path for contact with textile material passing out of said predetermined path, and means for completing said circuit through said textile material upon contact of said textile material with said electrical contact means and control supervision means positioned for actuation by current flowing through said circuit.

5. Apparatus according to claim 4 in which said last mentioned means comprise grounded means contacting said textile material.

6. Apparatus according to claim 4 which includes indicator means positioned in said open circuit.

References Cited in the file of this patent UNITED STATES PATENTS 2,330,212 Hayes et a1. Sept. 28, 1943 2,371,110 Searles et al. Mar. 6, 1945 2,400,837 Nesterowicz May 21, 1946 2,542,331

Hiensch Feb. 20, 1951

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