JPS6218468B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to a yarn tensioning device for tensioning a running yarn, such as a textile yarn or an industrial yarn, and more particularly to a yarn tensioning device that includes adjacent opposed yarn abrasive face members. , electromagnetic means for tension control of the fiber yarns are provided which are electronically controlled to produce an electromagnetic tension force in the yarns from a control device capable of controlling a large group of units tensioning the outgoing yarns substantially at selected tension values. The present invention relates to a thread tension control device.

Quality in most fiber treatments often depends on the accuracy or uniformity of tension in individual threads. Once yarn tension is lost or allowed to change at any point in the process, whether in repetitive operations, beam warping, texturing, knitting or other fabric forming, quality loss can occur. It is difficult or impossible to compensate. Spots, burrs, off yields, excessive knitting defects, and denier variations are common problems and are often caused by incorrect or uncontrolled tension in individual yarns.

Perhaps the most common type of tension device in use today is the post-and-plate tension device, in which thread is passed around a circular post to create friction and tension. The advantages of this type of tensioning device are its simplicity and low cost, but a significant drawback is that the tension generated by the winding depends on the amount of tension present in the thread as it approaches the winding post. There is. Since the tension in the thread exiting such a tensioning device is the tension from the source of the thread multiplied by a constant determined by the wrap angle or the number of columns, and the tension in the thread entering the column and board units is usually uncontrolled. Increasing the supply yarn tension several times merely increases the tension, which is not controlled. For example, considering a common example involving pulling yarn from a package cage for warping, the feed yarn tension to the column and plate tensioners is accelerated after the beam warper is stopped for slab removal. From 1/2 gram to a full package sent at 100 yards/minute,
This varies from 1 gram for a full package at full beam warper speed of 500 yards per minute to 3 grams when the package is nearly empty at full beam warper speed. How many times the tension (for example, 5
When these fluctuations are applied to the column and plate tension devices, the thread tension to the beam warper becomes 21/
The tension varies between 2 and 15 grams, resulting in a 6:1 tension variation, resulting in uneven finish, knitting defects, etc.

It is therefore an object of the present invention to provide a novel control-added system which can be electronically commanded to impart a certain tension value to the yarn being fed, thereby minimizing the disadvantages of uncontrolled input tension. An object of the present invention is to provide a thread tensioning device.

Another object of the invention is that the magnetic field of said electromagnetic coil is controlled by an electronic circuit which allows the tension value applied to the yarn to be easily adjusted to different desired values and provides very precise tension control over a wide range of fiber yarn tensions. It is an object of the present invention to provide a novel yarn tensioning device having an electromagnetic coil for applying a tensioning magnetic force to a yarn abrasive plate or shoe having yarn abrasive flat surfaces located in parallel vertical planes.

Another object of the invention is a novel thread tensioning device of the type immediately described above, wherein an electronic circuit adjusts the voltage level of a control signal applied to the tensioning device to determine the amount of tension applied. means include an operable tension setting potentiometer, and further include a negative voltage level periodically during adjustments of the potentiometer to reduce the voltage level of the tension control signal and thereby minimize residual magnetic effects. A device is provided that includes a degaussing circuit that provides a falling negative pulse to a coil.

Still another object of the present invention is to have a yarn wear surface member and an electronic circuit control device as described in the three paragraphs above, and to provide a control signal in response to yarn feed speed fluctuations to a predetermined level with respect to yarn speed fluctuations. It is an object of the present invention to provide a novel thread tension device having means for automatically changing the relationship between

Objects, advantages, and possibilities of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings that illustrate preferred embodiments of the invention.

The same reference numerals indicate corresponding parts throughout the figures. Referring to the drawings, and in particular to FIGS. 1-5, a preferred form of the thread tension control device of the present invention is designated by the reference numeral 15;
It consists of an electromagnetic coil 16 and an associated core assembly 17, said assembly being arranged to form a rectangular core loop, having a pair of core pieces spaced apart to form a gap, and having a thread 1 to be tensioned.
9 has flat surfaces located in vertical planes with parallel flat yarn abradable plates or shoes 18 located in parallel vertical planes passing between them. The electromagnetic coil 16 and core assembly 17 apply a controlled magnetic force to the abradable plate or shoe to make the permeable or magnetically attractive shoe or plate magnetically attractive with the appropriate force to apply the desired tension to the thread 19. Suction laterally into the shoe or plate.

Although apparatus 15 can be advantageously used in beam creel equipment, circular knitting machines, texturizers, winders, and other equipment where yarn tension control is desired, it will be described in connection with beam warping creel equipment. In a typical beam warping facility, the number of threads 19 drawn out from the creel assembly 21 shown in fragmentary form in FIG.
A number of such yarn tension control units 15 equal to A yarn sheet 26 is formed which passes through the small holes and is taken to a warper or beam warper 27. Each thread 19 from the package 22 has its own associated tension control unit 1.
The tension of each thread threaded through the warp cage 5 and thus exiting therefrom can be set to the desired value, and whether the package cage 22 is full or nearly empty, the warper 27
Substantially uniform tension can be maintained in all of the threads wound around the warper 27, whether the warper 27 is operating at full speed or at an intermediate speed during an acceleration period after stopping. Yarn tension control devices can be used for many other applications, providing tension control for each yarn entering the circular knitting machine, providing tension control for patterns, texture control and variation, uniform tension or pattern effects. will be understood.

In the embodiment of the thread tension control device 15 shown in FIGS. 1-6, the magnetic core assembly 17 is formed from a pair of parallel vertical side plates 30, 31 having upper end portions secured to the lateral support bar and pole piece assembly. It is in the form of a generally rectangular rigid frame consisting of. The support bar and pole piece assembly includes a pair of spaced apart pole pieces 33, 34 secured together by a support bar 32 and spaced apart to form a gap 35, with the ends of the pole pieces opposite the gap Hexagon socket screws 33a, 34
a to the vertical side plate and to the support bar 32 by hexagon socket screws 32a. Each pole piece 33, 34 has a flat front surface 33 adjacent the gap 35 and opposite the support bar 32 as shown.
b, 34b, which are perpendicular to the horizontal top and bottom surfaces and the vertical end surfaces of the pole pieces, and the thread abrasive shoe is mounted so as to be located in a vertical plane parallel to the pole piece front faces 33b, 34b. Ru.

The lower end portions of the vertical side plates 30, 31 of the core have a cylindrical core piece 3 extending through a plastic spool 37.
6 by hexagon socket head screws 30b, 31b, and the spool 37 is wound with approximately 6000 turns of "magnet" wire, e.g. When supplied with current, it produces a magnetic flux that extends through the vertical side plates 30, 31 and the pole pieces 33, 34 to the gap 35.

An abradable plate or tensioning shoe that variably applies tension to the yarn in relation to the force of the magnetic flux is indicated generally at 18 and is shown enlarged in FIG. The tensioning shoe assembly 18 is made of a non-magnetic material, such as non-magnetic stainless steel, and has a dorsal or rear part that is elongated in the direction of yarn travel and of sufficient length to span most of the distance between the vertical plates 30,31. flat rectangular shape 41
including. The back or rear shoe 41 has a pole piece 33,
located in a vertical plane opposite the front surfaces 33b, 34b of 34 and forming a back or rear abrasion plate or shoe for the yarn, indicated at 19, across which the yarn adheres to the holes in the side plates 30, 31. transition between the small inlet and outlet holes 28a and 28b. Directly in front of the back abrasive or tensioning shoe 41 for imparting a friction surface restraint force to the yarn to impart the desired tension, a magnetic metallic front or top abrasive or tensioning shoe 42 is disposed. is also a thin rectangular plate elongated in the direction of yarn migration. A plate or shoe 42 forms an armature bridge across the gap 35;
Also, the gap 3 is generated by the coil 16.
In response to the force of the magnetic flux directed into the plates 30, 31 and the pole pieces 33, 34 through the magnetic flux path across 5, it is drawn towards the shoe 41, imparting a tensioning force to the thread. Both ends of the shoes 41 and 42 are flared or curved around an axis extending perpendicularly to the transverse direction of the yarn path and away from the yarn along the cylindrical path as shown in the figure. are loosely assembled on horizontal support pins 44 which are fixed to the pole pieces and extend along a horizontal axis through holes in the shoes 41, 42, such that the abrasive plates or shoes are suspended on the support pins. In a typical beam creel installation, the opposing abrasive surfaces of the front and rear abrasive shoes 42, 41 coincide with the yarn path and the surfaces 33b, 3 of the pole pieces 33, 34 lie in parallel vertical planes.
It is parallel to 4b. In one satisfactory example, this configuration provides a tension control voltage of approximately 35 volts (current approximately 50 milliamps) supplied to the electromagnetic coil 16 of approximately 24 volts.
It produces a tension of grams.

The coil 16 and the adjacent lower portion of the core may be wrapped with a fixed cover section (not shown) and also include abradable plates or shoes 41, 42 and pole pieces 33,
34 as well as the upper core portion may be enclosed with a removable clip-type or U-shaped cover section, or may be provided with other forms of associated housing sections or the like as desired.

Figures 7A and 7B are schematic diagrams showing an overall electronic control system for remote manual adjustment control of a large number of yarn tensioning devices (for example, about 200 yarn tensioning devices) shown in FIGS. 2-6. be. In particular, Figure 7A,
Referring to Figure B, there is shown a power supply circuit, indicated generally at 50, which carries a three-phase rating of 440 volts to a rectifier 50-2 connected to a three-phase secondary winding 50-3 as shown. The output side includes a three-phase transformer 50-1 that steps down to approximately 26 volts. Additional secondary winding 50
-4 and 50-5 provide 18 volts AC and 30 volts AC as shown. Leads extending from the three-phase secondary winding 50-3 of the transformer 50-1 are connected to rectifier diodes 50-2 of the rectifier network 51, and output leads 51-A, 51-B are connected to unregulated +
Gives 26 volts DC. Lead 51-B is grounded. The +26 volt DC lead 51-A connects a pair of driver transistors 52-T1,5 to the tension adjustment control channel for the entire group of tensioners 15.
Providing a 2T collector power supply, the tensioning devices 15 can be powered by the channel to make up to about 200 tensioning devices. The 30 volt AC transformer secondary winding 50-5 is connected to a diode rectifying bridge 53 with the output side of the rectifying bridge as shown.
Connected to a capacitor 53-C1 to an integrated circuit regulator 53-IC such as the LM317K, and further connected to a resistor 53-C1.
-R1, 53-R2, 53-R3 and capacitor 53-C2, transistor 52-T
+28 volts for collector of 3,52-T4 and top of tension setting potentiometer 52-R1
DC regulated power is provided at 53-A.

The transformer's 18 volt AC secondary winding 50-4 is connected at its output to a diode rectifier bridge 54 coupled to a capacitor 54-C1 to provide -20 volts DC.
An unregulated power supply is provided at terminal 54-C to power a transistor with a degaussing circuit as shown and resistors 55-R1,5 connected as shown.
5-R2 and a capacitor 55-C1 to provide -15 volt regulated DC power to a degaussing circuit shown generally at 56.

As shown in FIG. 7A, the movable contact of tension setting potentiometer 52-R1 is connected to junction 52-J through resistor 52-R2, and potentiometer 52-R1 is connected to ground and to the regulated +28 volt power supply. connected between. Junction 52-J is connected to tension channel control resistor 52-T3 and to silicon diode 52-D1 to degauss control lead 59-1. The emitter of transistor 52-T3 follows the voltage set by the movable contact of 52-R1, and the emitters of driver transistors 52-T1 and 52-T2 follow the voltage set by the movable contact of 52-R1.
Track the voltage at the emitter of T4 and set the voltage supplied at output 58-2 to tensioning device 15. Also, junction point 52-J is ZN-5193 and MJ
-2955 transistor Darliton pair 58-T1,
58-T2 and connected to the first transistor 58-T1 of National Semiconductor Corporation.
Operational amplifier 57- formed from 741 operational amplifiers
is connected to the input network of the OA, which input network is connected to the tension setting potentiometer 52-R.
1 senses the initial decrease in the voltage level of 1 and applies voltage to gate circuit 59-G formed by transistors 59-T1 and 59-T2, causing it to provide a demagnetizing pulse to demagnetizing control line 59-1.

The degaussing circuit shown generally at 56 is associated with an integrated circuit voltage regulator 55-VR, which may be implemented on a Motorola 79MG integrated circuit, which voltage regulator is connected to grounded pin 1 of the integrated circuit 55-VR. Resistor 55 connected between leads from pins 2 and 3
-R2, and a resistor 55-R1 connected between pin 2 and ground. a -15 volt DC regulated power supply is provided across pin 3 of 55-VR to pin 1 of pulse generation integrated circuit 56-IC;
Integrated circuit 56-IC will be National Semiconductor's 555 integrated circuit. Pins 4 and 8 are grounded, resistor 56-R1 is connected between pins 8 and 7, and resistor 56-R2 is connected to potentiometer 56-R1.
In series with R3, this potentiometer serves as a pulse width adjuster and is connected between pin 7 and pins 6,2. Pin 3 is resistor 59-R
4 to the base of gate transistor 59-T1 of gate circuit 59-G, whose emitter is connected to a -15 volt regulated power supply and whose collector is connected to a +24 volt regulated power supply and to the base of gate transistor 59-T1 of gate circuit 59-G.
- connected to the base of T2, this transistor 5
The collector of 9-T2 is connected to the +24 volt power supply through resistor 59-R2. The collector of the gate circuit transistor 59-T2 is connected to the junction 52-
It is connected by a degauss control lead 59-1 to a silicon diode 52-D1 coupled to J.
The +24 volt power supply for gate transistors 59-T1, 59-T2 and operational amplifier 57-OA is derived from the +28 volt regulated power supply at 53-A by resistor 59-R6 and Zener diode 59-ZD as shown.

Since the integrated circuit 59-IC is wired as shown, the 10K pulse width adjustment potentiometer 59
-R3 provides width adjustment of the short duration pulse at output pin 3, and 220K resistor 59-R1 provides 59-
Sets the period of the square wave output produced by the IC. Operational amplifier 57-OA, whose output typically has an upper limit of +24 volts, holds gate transistor 59-T1 on through resistor 57-R1;
On the other hand, the resistor 57-R1 is connected to the gate transistor 5.
9-T2 is held off and this gate transistor connects line 59- to silicon diode 52-D1.
1 at +24 volts and diode 52-D1
to reverse bias. When operational amplifier 57-OA senses the initial decreasing voltage level of the movable contact of tension-setting potentiometer 52-R1, its output drops to -15 volts and gates transistor 59.
-T1 is turned off, which turns on gate transistor 59-T2 and connects line 59-1 to -15
Make it into a bolt. Next, the gate transistor 59
-T1 is turned on and off by the pulse output from pulse generator 59-IC, thus transistor 5
9-Turn T2 on and off at a pulse rate, line 59-
1 pulsates between +24 volts and -15 volts.
Potentiometer 60-R1 is transistor pair 6
0-T1, 60-T2 transistor 60-T1
The collectors of these transistors are connected at 54-C to the -20 volt D unregulated power supply. When line 59-1 goes to -15 volts, Darlington pair transistor 58-T1,5
8-T2 is switched on, causing the degaussing voltage on lead 58-1 to appear on tension voltage output line 58-2;
Turns off transistor 52-T3, which turns off transistors 52-T4, 52-T1 and 52-T3.
- Turn off T2. Gate transistor 52-
Line 59- each time T2 is turned off during the pulse waveform period.
1 returns to +24 volts, Darlington vs. 58-
T1, 58-T2 are turned off and transistors 52-T1, T2, T3, T4 are turned on.
This action causes the capacitor 57-OA to switch to the full discharge point, which is the point where the operational amplifier 57-OA switches to +24 volts and holds the gate transistor 59-T1 on.
This continues until C1 is reached. The emitter of 60-T2 is connected to the base of transistor 60-T3, whose emitter is connected to lead 58-1 to establish a negative level floor or bottom for the degauss signal.
Potentiometer 60-R1 therefore eliminates the floor or bottom of the degaussing pulse applied to tension control output 58-2 to eliminate the residual magnetism in the core of the tensioner, which is typically -2 or -3 volts. allows adjustment to the negative voltage level required.

The normal tension control voltage of the tension device 15 is, for example, 0.1
Generally 52- ohm resistor formed from
The assertiveness control output lead 58-2 is fed through parallel tangential emitter resistors shown as R1, 52-R2, each resistor connected to a driver transistor 52-T.
The base electrodes of these driver transistors are connected through resistor pairs 52-R3, 52-R4 to the emitters of transistors 52-T4, whose collectors are connected to +28 volts. A negative pulse applied from lead 58-1 to mask output lead 58-2 causes the gate formed by transistors 59-T1 and 59-T2 to be applied to master output lead 58-2 when transistor 58-T2 is turned on. connected seventh
Go to each tension device 15 schematically indicated by 15P in Figure B,
The control voltage to the electromagnetic coil is typically pulsed to the negative level of about -2 or -3 volts, while
The normal control voltage is simultaneously removed from master output lead 58-2 for the duration of each pulse via driver transistors 52-T1 and 52-T2. As shown, each tensioning device plug 15P may include a Zener diode as shown to dampen inductive feedback during pulsations.

Other forms of tensioning devices or abrasive surface assemblies for variably tensioning the yarn with respect to the magnetic flux force generated in the tensioning device in response to current supplied to the electromagnetic coil from the master output lead of the channel control circuit. is shown generally at 80 in FIGS. 8-11. In the tensioning device or abradable face assembly 80, the magnetic core assembly 81 is in the form of a rigid cup 82 of E-shaped cross section as shown with circular pole portions 83 spaced apart to form an annular gap 82a. and an annular pole section 84 . The polar portion is a flat front surface 83a located in a single plane adjacent to the gap,
84a, abutting the front surfaces of which a thread-abrasive face member is mounted in a vertical plane parallel to these. The cups 82 forming the pole portions are formed from a low coercivity steel, such as sintered or powdered metal iron, in the preferred embodiment to form a rigid magnetic core assembly.
The tensioning device also includes an electromagnetic coil 85, for example in the form of a "magnet" wire, which is made of approximately
6000 turns, wrapped around a cylindrical plastic spool 86 and attached to the annular wall of the cup 82 surrounding the cylindrical core portion 83, and connected to the tensioning device's remote control circuit (or integrated control circuit). ), the polar portions 83, 8
4 and the gap 82a to generate an appropriate magnetic flux.

A pair of disc-shaped abrasive surface members indicated by 88 and 89 forming the tension assembly 90 are attached to the pole surfaces 83a and 8.
It is supported along and parallel to the plane of 4.
These abrasive face members include an abrasive back surface or backplate 88 of a non-magnetic material such as non-magnetic stainless steel or brass, and in the illustrated embodiment has a diameter of about 1/3/
A Teflon washer 8 having a diameter of 8 inches spans most of the flat pole faces 83a and 84a and is disposed in a vertical plane and abuts the front faces 83a and 84a of the core.
9 abutting 7 and transitioning across the illustrated thread path
Forming an abrasive backside or backside for the yarn shown in 1. Immediately forward of the rear plate 88 or remote from the electromagnetic core and coil is a magnetic metal abrasive front plate 89 of substantially the same diameter as the mating abrasive face member 88; A friction surface restraining force is applied to the thread to add the desired tension. Abradable face plate 89 crosses gap 82a to form an armature bridge, which abradable in response to the magnetic flux force produced by coil 85 directed by the pole piece through a flux path spanning gap 82a. It is pulled laterally towards face plate 88 to apply tensioning force to the thread. The circumferential or edge portions of the abradable face plates 88, 89 are curved or bulged away from the yarn path along a convex curve as shown.

The tensioning device shown in Figures 8-12 is more advantageous than that shown in Figures 1-6 for certain yarns, with an output of 4 rpm for warping machines or 6 rpm for knitting machines.
A positive rotational drive force is applied to the abrasive back plate 88 from a motor 93, such as a low speed 24 volt, 60 cycle electric motor, which provides an output of . motor 93
is supported by a mounting post from a bracket or frame 94 that supports the electromagnet assembly and tension plate, and its output shaft is coupled to a plate drive shaft 95 passing through the center of cup 82 and non-circularly inserted into a non-circular opening in abrasive back plate 88. The circular front end forming part 95b is fitted and rotates the disc 88 in the forward direction relative to the feeding direction of the thread engaged therewith at a speed lower than that of the opposing part of the thread moving along the thread path. be. This creates a wiping action on the thread and in the space between the two opposing abrasive face plates 88, 89, which may adversely affect the proper operation of the tensioning device or cause additional damage to the thread. Prevents the accumulation of contamination or defects in this zone that could disturb the tension levels.

The front end of the disk drive shaft 95 terminates behind or flush with the vertical plane of the abrasive surface of the disk 88, and a ceramic shaft extension 95a is friction fit to the drive shaft 95 and passes through a central hole in the front disk 89. It projects forward and provides support for the disk 89 directly below the thread path. Shaft extension 95a is preferably made from a ceramic material to resist wear due to engagement with threads passing across the top of the shaft extension, avoiding wear of the thread by the shaft that would occur with brass or other materials. .

The front plate 89 is captured on the shaft extension 95a by a plastic cap 96 frictionally engaged with the extension 95a, which in the illustrated embodiment is connected to a coil portion surrounding and gripping the cap 96 and to the short axis of the front plate 89 or It carries a spring member 97 having a projection 98 and an engaged finger portion 97a. This causes the front plate 89 to be driven at a very low rpm of the rear plate 88, which tends to be driven to speeds close to the yarn transfer speed between the plates 88, 89 due to contact with the yarn.
This is to prevent you from exceeding the speed limit. This is because when the spring finger 97a rotates at the speed of the driven shaft 9 and the rear plate 88, the protrusion of the plate 89 comes into contact with the spring finger 97a, which rotates at the speed of the driven shaft 9 and the rear plate 88.
9 can no longer exceed this speed.

FIG. 12 schematically illustrates, at the point indicated at 12A, other portions of the electronic control circuit associated with those of FIGS. 7A and 7B, providing a velocity responsive tension equalizer or fader circuit; The yarn tension generated by the tension adjustment potentiometer 52-R1 is automatically varied so that the control voltage for the electromagnetic coils of the tensioning device of all groups is adjusted to the machine speed of the warper or beam warper or knitting machine. has a predetermined relationship with respect to fluctuations in the yarn, and the tensioning characteristics are automatically adjusted to the yarn feed rate. The circuit in Figure 12 is converted to point 1 in Figure 7A.
2A, the leads from points 12X to 12Y in FIG. 7A that connect the 12 volt regulated power supply to the top of potentiometer 52-R1 are omitted.

As shown in FIG.
- A timer signal from the PG is monitored, and in the warping installation this pulse generator can be driven from a press roll that abuts the yarn on the main warping roll and shifts with respect to the yarn speed. This can include peripheral slots, such as 180 slots in a 3-inch diameter wheel, through which light from a source such as an LED is directed to a photoelectric detector and into a Texas Instruments 7404 inverter. A pulse pattern as shown at 70- _P1 is applied to the input of an inverter shown at 70-I1. The converted pulse output from inverter 70-I1 is a positive pulse, as shown at 70- _P2 , whose leading edge corresponds to the leading edge of the negative pulse produced by the wheel in the pulse generator for each interruption of the beam. handle. As an example, the pulse generator produces one negative pulse for each 0.1 inch of yarn speed. The positive pulse 70- _P2 on the output side of the inverter 70-I1 is the one-shot multivibrator 7.
0-M1 to input pin 5, where the negative edge of positive pulse 70-P ₂ triggers a negative 1.5 μS pulse at the output as shown at 70-P ₃ . This negative pulse from the one-shot multivibrator 70-M1 can be applied to a 500K potentiometer.
Variable width one-shot multivibrator 70 with adjustable potentiometers designated 0-R1
- input pin 2 of M3, this potentiometer is connected to pins 6, 7 of variable width multivibrator 70-M3 through a 1K resistor 70-R2, and pin 3 of multivibrator 70-M3.
Adjust the width of the positive output pulse at .

Also, the positive output pulses at the output side of the inverter 70-I1 are supplied to the inverter 70-I2, and its output in the form of negative pulses is fed to the multivibrator 70.
-A one-shot multivibrator 70-M2 similar to M1 is fed to the input pin 6, which multivibrator is triggered by the positive-going edge at the end of the negative pulse at the output of the inverter 70-I1 and at 70- _P4 . generates a negative pulse shown, which is a negative 1.5 μS pulse triggered by the positive-going edge of the negative output pulse from inverter 70-I2. The pulse waveform 70- _P1 produced by the pulse generator has a substantially square waveform pattern, and the positive edge of the negative pulse supplied to the input side of the multivibrator 70-M2 is the pulse produced by the pulse generator. It is meant to occur approximately midway between two successive positive edges of the pattern. Therefore, the leading edge of the negative pulse 70- _P4 is the multivibrator 70
- two successive negative pulses 70 on the output side of M1 -
Occurs approximately midway between the two leading edges of P ₃ . Multivibrators 70-M1 and 70-M2 may both be made from Texas Instruments' 74121 integrated circuit. The negative pulse pattern 70- _P4 from the output side of the multivibrator 70-M2 is similar to that of the multivibrator 70-M3 and can be formed from the National Semiconductor's 555 integrated circuit. Supplied to input pin 2, potentiometer 70-R1
The setting of a manually adjustable potentiometer 70-R3 similar to and coupled thereto and connected through a 1K resistor 70-R4 to pins 6, 7 of a variable width one-shot multivibrator 70-M4. Creates a variable width positive pulse output in response to.

The output from pin 3 of the two variable width one-shot multivibrators 70-M3 and 70-M4 is applied via inverters 70-I3 and 70-I4, which are connected to a Texas Instruments 7404 inverter. It's possible,
Its output is supplied to input pins 1 and 2 of NOR gate 70-G1, which can be a 7400NOR gate, respectively, and the positive pulse on the output side of NOR gate 70-G1 is connected to inverter 70-I5 (I1-7404).
and transistor 7 through resistor 70-R5.
0-supplied to the gate of T1. The emitter of this transistor is grounded and the collector is connected to a regulated 28 volt power supply through resistor 70-R6. The collector of transistor 70-T1 is also connected to the gate of transistor 70-T2, and the emitter of transistor 70-T2 is
A 1K resistor 7 connected to a power supply regulated to 28 volts or whose collector is grounded by a 2K resistor 70-R8 and a 10 μf capacitor 70-CL.
0-R7 to the gate of transistor 70-T3. The collector of transistor 70-T3 is connected to a power supply regulated at 28 volts, and its base is connected via lead 70-RL to connection point 12A in FIG. A voltage is applied to the top of the tension adjustment potentiometer 52-R1 which determines the voltage applied to the master output lead of the electromagnetic coil.

The above circuit consists of a pulse train 70 at the output side of a variable width one-shot multivibrator 70-M3.
-P5 and one-shot multivibrator 7
The width of the irregularity of the positive pulses forming the pulse train 70-P6 at the output of the 0-M4 can be adjusted by adjusting the coupled potentiometers 70-R1 and 70-R3 to ensure a very small width of each half cycle. from a very short pulse that occupies only a portion of each half cycle and NOR gate 7
The pulses can be varied up to long pulses that slightly overlap each other in the 0-G1 output. This effect is achieved by potentiometer 70-R1, 70-R3
but the pulse width is such that the NOR gate is always raised for the longest pulse or lowered for most of the period for the shortest pulse, resulting in a train of pulses from two channels at the output of the inverter 70-I3, 70-I4. is to set. Tension adjustment potentiometer 25-R1 is adjusted to obtain the desired tension value, typically a value of e.g. 6 grams or 7 grams for very low warper speeds or what may be termed "stop tension." After giving
Set the warper to full speed and connect potentiometer 70-
"Running tension" by adjusting R1, 70-R3
The tension at the highest warper speed, which can be called "stop tension", is reduced to approximately the "stop tension" value. As the warper speed, and therefore also the pulse generator speed, increases, the pulse speed increases and brings the pulses at the outputs of the variable width one-shot multivibrators 70-M3, 70-M4 closer and closer to an overlapping pulse condition. . The potentiometers 70-R1, 70-R3 controlling these multivibrators 70-M3, 70-M4 provide a properly reduced voltage to the potentiometer 52-R1 to compensate for any overbalance in the maximum operating speed of the warping machine. will be adjusted to reach or very close to the pulse. As the pulse rate decreases as the warper speed decreases, the proportion of half-cycles occupied by these pulses gradually decreases from the overlap condition, and the voltage applied to tension adjustment potentiometer 52-R1 moves toward a full voltage of 28 volts. Increase gradually. Connection potentiometer 70-R
For a given pulse width setting of 1,70-R3, increasing the warper speed and pulse generator speed to increase the pulse rate and decrease the period between positive pulses in each channel will result in a 70-M3, 70-M4 The pulses on the output side gradually approach overlapping, and the stoppage ratio of the output of inverter 70-I5 gradually increases as the speed increases. However, the transistor 70-
TL, 70-T2 has a progressive non-conducting time that increases with increasing speed, and transistor 70-T2
Due to the DC averaging effect of resistor 70-R7 and capacitor 70-C1 on the input side of T3, the DC average output of transistor 70-T3 decreases with increasing speed and thus the tension adjustment potentiometer 5
The voltage applied to the top of 0-R1 is ramped down from the 28 volts DC available at the collector of transistor 70-T3. As an example, transistor 70-
T1 can be TN53 and transistor 70-T2 is
2N4402, transistor 70-T3 can be TN53.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a typical creel and warping facility having a yarn tension control device of the present invention for adjusting yarn tension to the warper, and FIG. 2 is a perspective view of the yarn tension control device of the present invention. , Figure 3 shows the abrasive plate disassembled from the pole piece, and is a perspective view similar to Figure 2, Figure 4 is a front view of the tension control device, and Figure 5 is 5-5 in Figure 4. Fig. 6 is a longitudinal sectional view taken along line 6-6 in Fig. 4;
Figures A and 7B are schematic diagrams of an electronic control system for manual adjustment control of multiple thread tension controllers in a multi-channel control system. 8th
The figure is a perspective view of a disk-type electromagnetic tension device embodying the present invention, FIG. 9 is a fragmentary exploded perspective view of the electromagnet and disk assembly of FIG. 8, FIG. The figure is a cross-sectional view taken along line 11-11 in Figure 10, and Figure 12 is a diagram showing Figures 7A and 7B in order to automatically change the magnetic tension generation force as the yarn speed fluctuates. 2 is a schematic diagram showing additional parts of the electronic control system attached to the circuit of FIG. 16... Coil, 17... Core aggregate, 19... Thread,
21... Creel aggregate, 26... Yarn sheet, 27...
Beam warper, 30, 31... Vertical side plate, 33, 3
4... Pole piece, 37... Spool, 41, 42... Tension shoe, 44... Support pin, 50-1... Three-phase transformer, 50-2... Rectifier, 50-3... Three-phase secondary winding, 51... Rectifier Network, 52-T1,5
2T... Driver transistor, 53... Rectifying bridge, 53-IC... Integrated circuit regulator, 54... Diode rectifying bridge, 55-R1, 55-R2... Resistor, 56... Demagnetizing circuit, 80... Wearable surface member assembly, 81... Magnetic core assembly, 82... Rigid cap, 83... Circular pole part, 84... Annular pole part, 85
... Electromagnetic coil, 86 ... Cylindrical plastic spool, 87 ... Teflon sheet, 88 ... Abrasive face plate,
89... Abrasive face plate, 91... Thread, 93... Motor,
94...Frame, 95...Panel drive shaft, 96...Plastic cap, 97...Spring member.

Claims (1)

[Scope of Claims] 1. A thread tensioning device for tensioning a thread, comprising an electronically controlled thread tensioning device, an electronic control circuit means, and both displacement means, the thread tensioning device comprises an electromagnetic core/coil assembly and a thread abrasion surface assembly, the electromagnetic core/coil assembly is disposed along the thread path and includes a rigid core structure; the structure has a core surface forming a gap located in a single vertical plane adjacent to and facing the associated yarn path; comprising a pair of opposing abrasive face members, both abrasive face members located in parallel vertical planes closely following said core surface and spanning said gap and through which the thread passes in frictional contact; forming generally planar opposed vertical thread contacting abrasive surfaces, the outer abrasive surface members furthest from said core structure being comprised of a magnetic material and responsive to a variable magnetic attraction of magnetic flux through said core structure; to vary the suction force directed horizontally inwardly toward the core structure, thereby varying the thread tension exiting the thread tensioning device; the member is movable in response to thread feeding motion of the thread engaged thereto, and the electronic control circuit means is electrically coupled to the electromagnetic coil of the electromagnetic core coil assembly to A control voltage applied to the electromagnetic coil is adjusted, thereby adjusting a magnetic force generated in the abradable surface member, and the surface displacement means moves one of the abradable surface members within a predetermined path along the yarn path. to continuously change the portion of the abrasive surface of the abrasive surface member that engages with the yarn, and the surface displacement means moves in an aligned relationship with the one abrasive surface member. and means for restricting the movement of said other abradable surface member to substantially corresponding movement. 2. A thread tensioning device according to claim 1, wherein the means for moving in registering relationship with the one abrasive face member includes restraining means for restricting the movement of the other abrasive face member to a substantially corresponding movement. Something that is equipped with. 3. The thread tensioning device according to claim 1, wherein the abrasive surface member is first and second opposed plates supported to rotate about a common central axis. 4. The thread tensioning device according to claim 1, wherein the abrasive surface member is first and second facing plates supported to rotate around a common central axis, and the surface displacement means is a motor, and the rotational output of the motor is coupled to the first plate to continuously rotate it. 5. The thread tensioning device according to claim 1, wherein the abrasive surface members are first and second opposing discs, the discs rotating about an axis forming a common central axis thereof. The surface displacement means includes a motor coupled to the first plate and having a rotational output for continuously rotating the same, and a motor extending from the shaft and having a rotational output for continuously rotating the second plate. and means for restraining the rotation of the first disk so as to substantially match the rotation of the first disk. 6. The thread tensioning device according to claim 1, wherein the abrasive surface members are first and second opposing discs that rotate about an axis forming a common central axis thereof. The surface displacement means is coupled to the first plate and has a motor having a rotational output for continuously rotating the same, and a motor extending from the shaft to rotate the second plate from the first plate. means for restraining the rotation of the first plate to substantially match the rotation of the first plate, the first plate being fixed to the shaft;
The second disc is loosely supported on the shaft, and spring finger means extending from the shaft engages an abutment on the second disc to limit rotation of the second disc. 7. The thread tensioning device of claim 1, wherein the control circuit means includes a manually adjustable tension setting potentiometer and responsive to the tension setting potentiometer adjusting the control voltage at variable voltage levels. means for applying short duration pulses to the electromagnetic core to predetermined different voltage levels intermittently to the electromagnetic coil in a direction of voltage drop during adjustment of the tension setting potentiometer;
degaussing circuit means for applying periodic voltage pulses to the coil to thereby demagnetize the electromagnetic core to minimize residual magnetic effects in the core structure of the tensioning device. 8. The thread tensioning device of claim 1, wherein the control circuit means includes a manually adjustable tension setting potentiometer and responsive to the tension setting potentiometer adjusting the control voltage at variable voltage levels. means for applying to the electromagnetic core a negative pulse dropping to a predetermined negative voltage level to the electromagnetic coil intermittently in a voltage dropping direction during adjustment of a tension setting potentiometer, thereby dropping to a negative voltage level; degaussing circuit means for applying periodic voltage pulses to the coil to minimize residual magnetic effects in said core structure of the tensioning device. 9. The thread tensioning device of claim 3, wherein the control circuit means includes a manually adjustable tension setting potentiometer and responsive to the tension setting potentiometer adjusting the control voltage at variable voltage levels. means for applying to the electromagnetic core a negative pulse dropping to a predetermined negative voltage level to the electromagnetic coil intermittently in a voltage dropping direction during adjustment of a tension setting potentiometer, thereby dropping to a negative voltage level; degaussing circuit means for applying periodic voltage pulses to the coil to minimize residual magnetic effects in said core structure of the tensioning device. 10. The thread tensioning device of claim 5, wherein the control circuit means includes a manually adjustable tension setting potentiometer and responsive to the tension setting potentiometer adjusting the control voltage at variable voltage levels. means for applying to the electromagnetic core a negative pulse dropping to a predetermined negative voltage level to the electromagnetic coil intermittently in a voltage dropping direction during adjustment of a tension setting potentiometer, thereby dropping to a negative voltage level; degaussing circuit means for applying periodic voltage pulses to the coil to minimize residual magnetic effects in said core structure of the tensioning device. 11. The thread tensioning device of claim 6, wherein the control circuit means includes a manually adjustable tension setting potentiometer and responsive to the tension setting potentiometer adjusting the control voltage at variable voltage levels. means for applying to the electromagnetic core a negative pulse dropping to a predetermined negative voltage level to the electromagnetic coil intermittently in a voltage dropping direction during adjustment of a tension setting potentiometer, thereby dropping to a negative voltage level; degaussing circuit means for applying periodic voltage pulses to the coil to minimize residual magnetic effects in said core structure of the tensioning device. 12. A thread tensioning device according to any one of claims 7 to 11, wherein the degaussing circuit automatically senses the occurrence of a reduced voltage level at the movable contact of the tension setting potentiometer. circuit means responsive to said means for providing said intermittent negative degaussing pulses to said electromagnet upon sensing a decreasing voltage level at said movable contact. 13. A thread tensioning device according to any one of claims 8 to 11, wherein the degaussing circuit means generates a series of substantially rectangular negative pulses and adjusts the pulse width of the pulses. an oscillator having a potentiometer to provide the control voltage to the coil, regulated by a voltage provided by the potentiometer; transistor circuit means for providing the control voltage to the coil in response to a pulse train output of the oscillator circuit; gate transistor means for turning on and off transistor circuit means for applying a selected negative voltage level to the coil when the transistor circuit means is off so that the setting of the tension setting potentiometer is set to a low voltage; during each degaussing pulse, regardless of the set point, as long as the voltage level of the control voltage supplied to the coil pulses to a negative voltage level. and means for providing a negative demagnetizing pulse output. 14. The yarn tensioning device according to claim 1, comprising yarn speed responsive tension equalizer means, the yarn speed responsive tension equalizer means generating a pulse train at a pulse rate related to the yarn feeding speed to the utilization device. pulse generating means for automatically changing the control voltage applied to the coil by the control circuit means in response to the pulse speed of the pulse in an inverse relationship in response to changes in yarn feeding speed; and means for minimizing changes in yarn tension due to a tensioning device due to changes in yarn feed speed. 15. The yarn tensioning device according to claim 3, comprising yarn speed responsive tension equalizer means, the yarn speed responsive tension equalizer means generating a pulse train at a pulse rate related to the yarn feeding speed to the utilization device. pulse generating means for generating a voltage applied to the coil by the control circuit means in response to the pulse rate of the pulse;
and means for automatically changing the thread tension in an inverse relationship in response to changes in the thread feed speed to minimize changes in the tension of the thread due to the tension device due to changes in the thread feed speed. 16. The yarn tensioning device according to claim 7, comprising yarn speed responsive tension equalizer means, the yarn speed responsive tension equalizer means generating a pulse train at a pulse rate related to the yarn feeding speed to the utilization device. pulse generating means for automatically changing the voltage supplied to the potentiometer in response to the pulse speed of the pulse in an inverse relationship corresponding to changes in the yarn feed speed; means for minimizing changes in the tension of the thread caused by the tension device as the tension changes. 17. The yarn tensioning device according to claim 9, comprising yarn speed-responsive tension equalizer means, the yarn speed-responsive tension equalizer means generating a pulse train at a pulse rate related to the yarn feed speed to the utilization device. pulse generating means for automatically changing the voltage supplied to the potentiometer in response to the pulse speed of the pulse in an inverse relationship corresponding to changes in the yarn feed speed; means for minimizing changes in the tension of the thread caused by the tension device due to the change. 18. The yarn tensioning device according to claim 10, comprising yarn speed responsive tension equalizer means, the yarn speed responsive tension equalizer means generating a pulse train at a pulse rate related to the yarn feeding speed to the utilization device. pulse generating means for automatically changing the voltage supplied to the potentiometer in response to the pulse speed of the pulse in an inverse relationship corresponding to changes in the yarn feed speed; means for minimizing changes in the tension of the thread caused by the tension device as the tension changes.