SE440066B - SET AND DEVICE FOR REGULATING THE PROMOTION OF TRAD BETWEEN A TRADING SUPPLY AND A CONSUMER BODY - Google Patents

Description

And tensioning devices in an attempt to reduce thread twisting and thread breakage and to equalize stresses caused by intermittent removal of thread from a supply by the loom's weft insertion system. An example of such a drum storage device is shown in U.S. Pat. No. 3,776,480, which also shows the drums and their operation. The purpose of these drums is to provide wire feed from the drum to the wire consumable under constant wire tension.

It is also known to sense the wire layer on the intermediate drum and to change the take-out speed by reducing the wire feed rate each time the wire layer becomes too large. This technique is disclosed in U.S. Pat. No. 3,225,446, which describes a so-called "multiple ratio differential" for increasing and decreasing the feed rate in response to detecting a corresponding decrease or increase in the wire layer. Another example of such a speed control is shown in U.S. Pat. No. 3,796,385, according to which a pivotable mechanical wire pre-rotor sensor and a corresponding electrical contact switch are used to change the feed rate by turning on and off an AC motor drive circuit.

Known drum storage devices for regulating voltage to the consumable are designed either to continuously change the speed of the drum drive motor and to establish repetitive acceleration-deceleration phases or to change the motor speed according to the feed load in order to provide constant torque driving. In both cases, wire separation is promoted through the restoration of bays and / or wire breakage through repeated accelerations. The feed load and thus the speed can be drastically changed.

Speed variations due to frictional changes between cold start conditions and stable temperature conditions have been measured to as much as 70%. Measurements of the storage package have also been found to vary several hundred grams when measured. In AC motors, the slip speed varies with the load. The speed of a DC motor is sensitive to both voltage and load variations.

Known constructions and then especially drive arrangements with constant torque have over wide ranges of operating conditions led to unresolved problems when winding wire from a storage package on a drum. Load changes resulting from wire package tensions and frictional forces in the bearing feed device in particular prevent operation at a speed which is adapted to the removal speed of the loom. In an attempt to solve this problem, the bearing feeding device has usually been operated at speeds which substantially exceed the speed of the weft wire consumption. As a result, the wire from the supply package has been intermittently stopped and started and promoted wire separation and wire breakage.

Accordingly, the main object of the invention is to solve these problems in a wire tensioning device with intermediate drum bearings and tension control means by considerably reducing from changes in the motor drive speed or load resulting from wire separation or wire breakage.

This object is achieved in the initially stated method according to the present invention in that a wire feed means is driven via an electric drive means for advancing wire from the wire supply and winding the wires on the feed means for subsequent output to the consumption means, that the current flow to the drive means is regulated to bring the feed means for feeding the wire from the wire supply at a second substantially constant, predetermined average speed which is slightly higher than said first predetermined average speed, that the accumulation of wire on the feed means is detected, that the current flow to the drive means is interrupted when the amount of wire on the feed means exceeds one amount and that said interruption is limited to keep the wire bend and the wire voltage at substantially constant levels when the current flow is interrupted.

This object is also achieved with a device, which according to the present invention is characterized by a drum feed means, which is arranged to receive wire from the supply and wrap it around a drum for subsequent discharge to the consumption means, a variable speed DC motor, which is arranged to rotate the feed means to thereby extract wire from the supply at a speed determined by the rotational speed of the feed means, an electrical circuit which is arranged to supply direct current to the motor and comprises a speed control means which is programmable to in response to detecting the actual output speed of the motor, establish a constant speed for the DC motor, and a selectively adjustable voltage connection means coupled to the speed control means for establishing a wire feed rate slightly higher than said predetermined average speed, a detector means, which is arranged to detect the presence of an excess amount of wire on the drum and in such a case to emit a control signal, and an on-off control means included in said circuit for the motor, which is arranged to be actuated by the detector means' control signal to interrupt the power supply to the motor thereby reducing the wire feed rate and which has such a response time that the wire bay and wire tension are maintained at substantially constant levels during the time the power supply to the motor is interrupted.

The invention will now be described in more detail with reference to the accompanying drawings.

Fig. 1 is a schematic block diagram showing various elements for driving a bearing feed device at a constant speed.

Fig. 2 is a schematic circuit diagram showing a preferred control system according to the invention.

As shown in Fig. 1, a shuttle-free loom 10 consumes an addition of wire Y, which it takes from a storage package 12 in a manner conventional for shuttle-free looms with substantially constant tension by means of of an intermediate rotary drum bearing and tension assembly 14. The bearing and tension assembly 14 may have such a shape and may include such conventional details as shown in the aforementioned U.S. Pat. No. 3,776,480, and have a drum 16 on which the wire Y is wound. from the package 12, when the thread is fed to the loom 10. The drum 16 of the unit 14 is arranged to take thread Y from the storage package 12 and feed the thread with constant tension to the loom 10.

The unit 14 has a main shaft 20, which is connected to and driven by a variable speed electric DC motor 22 and which is in fact arranged as an armature in the motor 22. The shaft 20 has a cutter 26 for receiving a crank-shaped wire tube 30. The tube 30, which is hollow, acts as a guide means for the wire from the supply 12. The wire is guided through the tube 30 and out of its end 32 to be wound around the drum 16, when the shaft 20 and the tube 30 are rotated by the motor 22. In the case shown the embodiment thus feeds the shaft 20 and the tube 30 the wire. As the wire is wound on the drum 16, it is advanced from the first end 38 of the drum 16 to its second or distal end 40 by means of a wire feeding mechanism 44, which is described in more detail in the aforementioned U.S. Pat. No. 3,776,480. The wire is dispensed over the drum. 16 end and is pulled over a tapered nose piece 48, which is mounted on the shaft 20, and is guided under a stationary brush 50, which abuts against the surface of the nose piece 48. The brush 50 thus forms a control means for the thread pulled out of the drum 16 from the drum 16. The wire is guided from the nose piece 48 through a guide 54, which is supported by a holder 56, which is attached to a stand 60 for the drum 16 and associated part and is then conveyed to the loom 10. The drum 16 is held when winding wire Y on the drum and removal of wire therefrom by means of a plurality of magnets 64. The drum 16 is supported on the shaft 20 by means of ball bearings 66 and 68, which are arranged at the ends of the drum and insulate the drum from the rotational movement of the shaft 20. The unit 14 described above is described in more detail in the aforementioned U.S. Pat. No. 3,776,480.

As already mentioned, the shaft 20 of the unit 14 is driven by a variable speed electric DC motor 22.

Other drive means, such as a gear or a drive belt, may, if desired, be used to provide a suitable shaft speed in response to the running speed of the DC motor 22.

A control system comprising an SCR phase control circuit 70 (phase control circuit with controlled silicon rectifier) establishes by +20 V DC at a terminal 72 a varying DC voltage in a motor line 74 to control the motor speed, when different load conditions exist, such as the above-mentioned intermittent voltage load for the wire Y when it is pulled out of the package l2 or the friction of the system during cold start-up.

In this way, under all operating conditions for long operating periods, an adaptation of the extraction speed of the wire Y from the storage package 12 to the consumption of the loom 10 is ensured.

In order to achieve such a control of the nominal motor speed that it is carefully adapted to the speed desired for feeding wire on the drum 16 from the supply package 12 at the same average speed as the one with which the wire is taken out of the loom 10, a selective manually adjustable RPM voltage control means 78. This means provides a running speed setting for the unit 14, which is then continuously operated at a constant speed by means of a feedback circuit comprising a motor speed detector 80 and a speed responsive voltage converter circuit 82. To further reduce the system load changes, the detector 80 is preferably a contactless magnetic detector of the Hall effect type which senses passing poles of a set of six rotating magnets 84 arranged on a disk 86 which is rotated by the motor 22.

The "frequency-voltage" converter circuit 82 thus senses a frequency which is proportional to the speed of the motor 22 in order to convert it to a corresponding control voltage. This correction control voltage is provided by the SCR phase control circuit 70 with a feedback strength which tends to keep the DC motor speed constant at the speed set by the RPM voltage control means 78 when changing load, voltage or other variable system conditions.

This constant speed drive of the unit 14 prevents frequent acceleration and deceleration phases, which cause wire separation or wire breakage of the wire Y, which is fed to the drum 16 from the supply package 14.

In order to provide proper function for the intermediate bearing drum 16, the amount of wire stored on the drum 16 by a pivotable ferroel element 90 is sensed.

This sensing is accomplished as well as sensing the motor speed without additional friction or load by means of a Hall effect type magnetic detector 92 and is performed each time the wire supply on the drum becomes too large by pivoting the element 90 away from the detector 92. or vice versa. In this case, an on-off control circuit 94 is operated for the DC motor 22 to prevent too much wire from being wound on the drum 16 for any reason, for example a loom stop.

In operation, therefore, the RPM voltage regulator 78 is adjusted in such a way that the speed of the shaft 20 is very close but slightly exceeds the speed required to adapt to the removal of wire from the drum by the loom 10. The on-off control circuit 94 therefore rarely needs to be actuated to routinely correct wire overfill, so the necessary acceleration-deceleration phases caused by engine shutdown and restart are minimized to avoid corresponding voltage and bay problems when pulling the wire bay 98 off. 7908572-6 10 15 20 25 30 35 8 the storage package 12 to the drum 16.

It will thus be seen that the shaft 20 of the unit 14, with the exception of these infrequent deviations, is driven at a constant speed by continuous supply of wire Y from the supply package 12 to the drum 16 at a speed which is adapted to the mean value of the take-out speed of the loom 10. Therefore, no change in the speed of the unit occurs during routine operation.

The electrical control circuit is shown in Fig. 2. Against each other corresponding parts have the same reference numerals in Figs. 1 and 2.

The magnetic motor speed detector 80 is a Hall effect device which senses six magnetic poles per rotational revolution of the disk 86 in Fig. 1 to deliver to an input network 81 pulses of suitable frequency for processing in the frequency-voltage converter circuit 82. The driving voltage + of the circuit 12 V DC at a terminal 100 as well as the motor drive voltage +20 V DC at terminal 72 are obtained from a suitable DC source (not shown).

All circuit parameters are shown, and the various elements shown in block form are conventional, commercially available units, which are described in more detail below.

The resulting variable voltage output signal, which is proportional to the actual drum shaft rotation speed, is obtained in a line 104 for connection to the connection 106 of the SCRf motor speed control circuit 70 and has such a strength that the speed of the motor 22 is regulated to compensate for changes in load. , voltage, etc. during operation by regulating the SCR device 70 in series with the motor 22 in the drive voltage supply path from the socket 72.

The motor speed signal emitted by the detector 80 is supplied to a frequency-voltage converter circuit 82, which converts the output pulses of the detector 80 into direct voltage.

This DC voltage level is controlled by the voltage regulator 78, which establishes the nominal running speed of the motor 22 and is therefore set to adjust the rotational speed of the unit 10 15 20 25 30 35 7908572-6 9 14 so that it corresponds to the average speed of the consumption of the consumption means.

The Hall effect type magnetic detector 92, which senses the bearing level of the trees on the drum 16, controls a transistorized electronic switch circuit 110, which is arranged to selectively establish a substantially ground voltage level in the line 105 by means of a transistor 111 to thereby prevent motor current flow through SCR ~ device and turn off the engine. Preferably, the motor is completely turned off so that the circuit stops the unit 14 in response to wire feed errors, etc., and further monitors the storage capacity of the drum 16 to ensure that the drum is not overwound. Only the over-winding capacity needs to be sensed for on-off control for performing the bearing monitoring function, if the RPM control means 78 is set for a drum shaft speed which is slightly greater than the speed required for feeding the consumption means, whereby the number of changes in the motor speed is minimized in comparison with the repetitive change of the drum shaft speed required by previously known devices and thereby a considerable increase in the risk of wire bends and wire breakage.

The preferred embodiment further has the advantage that it provides efficient control which does not in any way strain the drum or wire drive paths and nullifies the precise conditions necessary for high speed interference-free wire treatment during long periods of operation. This is achieved by the electronic-magnetic sensing arrangement, which further has a long service life without mechanical wear or electrical contact problems. The sensing frequency parameters and the electronics circuit time constants, as established by the RC networks therein, are ideally adapted for rapid response to the intermittent, instantaneous load conditions obtained by removing wire from a coil or resulting from system friction, etc., which are not 7908572- 6 10 15 20 25 30 35 10 can be followed by mechanically actuated sensing means or mechanically movable control means.

The circuit technology itself is conventional outside of this particular system, and the circuits may be designed differently. The preferred embodiment, which provides a combination of improved and cooperating operating characteristics, is made up of the following commercially available components: Model l2FP, manufactured by Printed Motor Division Kollmorgen Corporation Glen Cove, New York Motor 22 --- Model UGN-3020T , manufactured by Sprague Electric Company Concord, New Hampshire Hall Power --- Detector 80 and 92 Component No. RC4151NB, manufactured by Raytheon, Semi-Conductor Division Mountain View, California Frequency --- Voltage Converter Integrated Circuit Model No. L 120B1, manufactured by SGS-Ates Semiconductor Corporation Newtonville, Massachusetts SCR Motor Speed Control Integrated Circuit It will be apparent from the above description of the invention and a preferred embodiment thereof, that a new and improved systems for regulating the voltage and feed conditions of wire fed from a supply spool to a consumable means, such as a loom. By controlling the rotational speed of the intermediate bearing drum tensioning device to provide a constant speed which is adapted to the average value of the continuous thread consumption rate of the loom, the occurrence of the acceleration-deceleration phases which tends to lead to 7908572-6 ll wire separation or wire breakage, considerably reduced in comparison with previously known devices with drum speed control. Thus, according to the present invention, there is provided a more reliable, long life wire feed device for regulating wire tension to a loom, which device reduces wire separation and wire break problems over a wide range of wire sizes and feed rates.

Claims (8)

7908572-6 '10 15 20 25 30 12 PATENT REQUIREMENTS A method of controlling the feed of wire between a wire supply (12) and a consumable means (10), which requires wire feed at a first substantially constant, predetermined average speed, the wire being taken out over the end of the supply and forming a bay around the supply, characterized in that a wire feed means (14) is driven via an electric drive means (22) for feeding wire from the wire supply (12) and winding the wire on the feed means (14) for subsequent output to the consumption means (10), that the current flow to the drive means (22) is controlled to cause the feed means (14) to feed the wire from the wire supply (12) at a second substantially constant, predetermined average speed, which is slightly higher than said first predetermined average speed, that the accumulation of wire on the feed means (14) it is detected that the current flow to the drive means (22) is interrupted when the amount of wire on the feed means exceeds a predetermined amount and that said interruptions are limited to keep the wire bay and wire tension at substantially constant levels when the current flow is interrupted. 2. A method according to claim 1, characterized in that the winding speed of the feed means (14) is kept constant by means of a feedback control means (80, 82), which is arranged to react for the actual winding speed of the feed means. 3. A method according to claim 2, characterized in that the step of causing the feed means (14) to feed the wire at a substantially constant winding speed comprises using a variable speed DC motor (22) as a drive means and that the voltage connected to the direct current motor is regulated in order to achieve this constant winding speed. 15 15 20 25 30 35 7908572-6 13 winding speed. 4. A method according to claim 1, characterized in that the feeding means (14) comprises a drum (16), on which the wire is wound and whose rotation is prevented. Device for feeding wire between a wire supply (12) and a wire consumable (10), such as a textile machine, which requires wire feed at a substantially constant average speed, the wire being unwound over the end of the supply and forming a bend around the supply, characterized of a drum feed means (14), which is arranged to receive wire from the supply (12) and wrap it around a drum (16) for subsequent discharge to the consumption means (10), a DC motor (22) with variable speed, which is arranged rotating the feed means to thereby remove wire from the supply at a speed determined by the rotational speed of the feed means, an electrical circuit which is arranged to supply direct current to the motor (22) and comprises a speed control means (70) which is programmable to establish a constant speed for the DC motor (22) in response to detection of the actual output speed of the motor (22), and a harness an adjustable voltage connection means (78) coupled to the speed control means for establishing a wire feed rate slightly higher than said predetermined average speed, a detector means (92) arranged to detect the presence of an excess amount of wire on the drum (16) and in such a case to emit a control signal, and an on-off control means (94) included in said circuit for the motor (22), which is arranged to be actuated by the control signal of the detector means (92) for interrupting the power supply to the motor and thereby reduce the wire feed speed and which has such a response time that the wire bay and the wire tension are kept at substantially constant levels during the time the power supply to the motor is interrupted. Device according to claim 5, characterized in that the speed control means (70) is arranged to regulate the direct voltage of the motor (22). 7. Device according to claim 6, characterized by a means, which is arranged to generate a variable voltage in response to changes in the output speed of the motor (22) for changing the direct voltage to the motor. Device according to claim 7, characterized in that a contactless magnetic coupling (80) is arranged to detect the output speed of the motor (22) in order to generate a variable feedback voltage in response to speed changes.