EP3293295B1

EP3293295B1 - Measurement system for a machine that processes a continuous strand like textile material

Info

Publication number: EP3293295B1
Application number: EP17190938.5A
Authority: EP
Inventors: Srinivasan Varadarajan
Original assignee: Premier Evolvics Pvt Ltd
Current assignee: Premier Evolvics Pvt Ltd
Priority date: 2016-09-13
Filing date: 2017-09-13
Publication date: 2021-08-04
Anticipated expiration: 2037-09-13
Also published as: CN107815761A; EP3293295A1; ES2892076T3

Description

The invention relates to the field of textile machines processing strand like materials and in particular to a measurement system for a machine that processes a continuous strand like textile material as described in the preamble of the corresponding independent claim.
In a spinning mill,

spinning machines create an elongated yarn from roving and wind the yarn on cops, and
winding stations transfer and combine the yarn from a plurality of cops to packages.

Spinning machines can be equipped with sensors that allow to determine production parameters, such as

running status of the yarn, breaking of the yarn and an associated time loss, startup breaks, mending time, idle spindles, rogue spindles, worst spinning positions, actual spindle speed, speed of yarn or volume of production, etc.

In more detail, a ring spinning machine has plurality of spinning positions or spinning stations where the yarns are running. This is called "running status" of the yarn. A yarn can stop running either due to a "machine stop" where all the spinning positions stop running. Alternatively, when a yarn breaks in a spinning position, that position alone will stop running. The second case is called a "yarn break". The machine running status and a position running status together are "measured parameters" and from these two, one can calculate many "derived parameters" like idle spindles, mending time, rogue spindles, worst spinning positions, volume of production etc.
Speed of yarn i.e. rotational speed of the yarn and the delivery speed of the yarn are "measured" parameters too and these can be used to determine "derived parameters".
Particular break types like startup breaks, idle spindles etc. are derived depending on the situation. For example, startup breaks refers to breaks which happen immediately when the machine starts running with a new package loaded. Idle spindles refers to the spindles having a break time that exceeds a given time limit. For example, spinning positions where the break time is greater than 30 minutes are treated as idle spindles.
In general, production parameters are related to a quantity of a production process and/or to a status of a production machine.
Winding stations or separate testing machines can be equipped with yarn quality sensors that allow to determine quality parameters, such as

yarn thickness or evenness and coefficient of variation and deviation rate thereof, impurities like thick places, thin places, neps, hair properties, diameter, linear density, presence of foreign materials and vegetable matters etc.

A winding machine can have a quality measuring head to monitor, measure and cut faults in the yarn. Generally, faults are classified as neps, short thick places, long thick places and long thin places. In addition or alternatively other parameters like evenness, hairiness, imperfections, the presence of foreign materials and vegetable matters etc. can be monitored.
Parameters like thick, thin, neps, evenness, and other faults can be derived from a signal given by a mass sensor, which can be a capacitive or an optical sensor. Hairiness, foreign materials, vegetable matters are usually determined by optical sensors in a winding machine.
A winding machine is the final stage of a spinning process, where the above faults, when exceeding given deviations from reference values, should not be allowed. Hence whenever a deviation that is classified as a fault occurs (it can be thick, thin, nep, evenness, hairiness etc.), a cut will be initiated, thereby stopping production, and the winding machine will remove the fault, piece the yarn together automatically and continue production.
Generally in ring spinning machines such online quality measurement is not available due to many technical constraints. Also, it is not desired to stop production when there is a deviation in a quality of a spinning position. If production is stopped, it will halt the entire production of the ring spinning shed.
In general, quality parameters are related to a quality of a product, that is of a yarn, or more generally, of a strand like textile material.
Production parameters and quality parameters can be measured at various places in a spinning mill: As an example, US 5,517,404 describes a process control system for a spinning mill, having ring spinning positions each with a sensor for ascertaining whether it is in operation or not, and winding stations having winding positions each with a yarn tester for monitoring yarn quality parameters.
Often, rather than testing quality parameters in a winding station, off-line testers such as evenness testers are used in which samples taken from out of the production process are analysed in a laboratory and then discarded. Only a small sample of the produced yarn is tested.
Furthermore, it is generally known to measure production parameters on ring spinning machines by means of stationary or travelling sensors for detecting yarn breakage. Sensors can be attached to delivery rolls of a spinning machine, measuring the roll speed and therefrom determine production parameters such as total production, down times, numbers of doffs per shift, doffing time etc.
US 6,112,508 discloses an apparatus for monitoring yarns on spinning machines, with a sensor travelling along a track in front of the spinning positions of a spinning machine to be such that mavericks and other forms of unevenness in the yarn can be located. The sensor is an optical sensor that detects the diameter of the yarn rotating around the spindle, i.e. in the yarn balloon, according to light reflected from the rotating yarn.
EP 0 375 012 discloses a photoelectric or capacitive or piezoelectric transducer positioned under the last pair of drafting rollers. They are mounted one at each spinning spindle, to check the quality of yarn.
EP 1 574 607 discloses a system and method in which online quality data and results from an offline testing system are involved. This is for the specific purpose of replacing measurements made in an offline testing machine by the online quality measurement.
EP 3 009 388 discloses an integrated sensing, control and resurrection system for yarn breakage.
DE 198 32 002 discloses a monitoring unit for an open end spinning machine.
JP S62 57956 discloses a display unit for a yarn monitoring device.
It is an object of the invention to create a measurement system for a machine that processes a continuous strand like textile material of the type mentioned initially, which allows to more precisely and efficiently control production of a strand like textile material, in particular in a spinning machine.
It is a possible further object of the invention to create a measurement system for a machine that processes a continuous strand like textile material of the type mentioned initially, which allows to improve production quality and/or quantity in a spinning mill.
At least one of these objects is achieved by a ring spinning machine according to claim 1.
The measurement system for a machine that processes a continuous strand like textile material, wherein the machine is a ring spinning machine according to claim 1 comprising a plurality of spinning positions, the measurement system comprising

a plurality of quality measurement units each configured to continuously measure at least one quality parameter of at least one strand of the strand like textile material being continuously transported within the spinning machine.

Arranging for such on-line yarn quality testing in a ring spinning machine according to claim 1 allows for at least one of the following benefits:

On-line testing allows for adjusting machine parameters, thereby improving the quality of yarns in the spinning phase, which then gives a good running performance of these yarns in the successive departments like auto winders.
Monitoring directly on the spinning machine and for each spinning position makes it easy for technical personnel to monitor and control the quality of yarn produced when compared to the existing laboratory testing methods
Production of bad quality yarns in specific spinning positions can be identified and defects can be rectified immediately, which is not possible in off-line laboratory quality testing methods.
Maintenance personnel in ring spinning department can identify defective yarn positions there itself and can take corrective actions immediately. This can save a huge time for carrying the bobbins from department to laboratory, testing and results analysis as in case of laboratory testing methods.
The maintenance frequency of the ring spinning machines and the replacement and/or maintenance of components used in the yarn manufacturing can be scientifically founded by analysing the quality information of yarn produced in the ring spinning machines.
Comparison of quality of yarn from each spinning position in relation to the adjacent and other positions can be performed on-line, during production.
In the case that there are deviations from the norm in the preceding spinning preparation processes like carding, combing, draw frames etc., corresponding deviations and faults will get noticed in a plurality of the spinning positions. They can be analysed further by an operator to understand the cause and source of the deviation.
Based on long term information from the on-line quality measurement at the spinning stage, it is possible to analyse the effect of raw material quality on the quality of the textile material produced in the spinning machines.

It can be the case that each of the plurality of spinning positions is associated with an individual quality measurement unit.
It can be the case that the measurement system comprises only one quality measurement unit in only one spinning position for only one strand.
The at least one quality measurement unit comprises a first sensor that is capable of determining at least one first sensor signal from which the quality parameter can be determined, and a first signal processing unit for determining the quality parameter from the first sensor signal.
It can be the case that the first sensor comprises at least one quality sensor element arranged to measure the at least one quality parameter at one spinning position of the spinning machine. The first sensor can comprise a plurality of sensor elements/multiple quality sensors elements.
It can be the case that the first sensor is arranged to generate a single first sensor signal

from readings of a single one of the at least one quality sensor elements, or
from readings of two or more of the at least one quality sensor elements.

It can be the case that the first signal processing unit is arranged to determine one or more quality parameters from one or more first sensor signals from a single spinning position.
It can be the case that the first signal processing unit is arranged to determine one or more quality parameters from one or more first sensor signals from a plurality of spinning positions.
The measurement system comprises

at least one production measurement unit each configured to continuously measure at least one production parameter that characterises a running status of at least one strand of the continuously transported strand like textile material,

spinning positions is

Examples for the running status can correspond to the following: "Running" or "stopped". Parameters associated with "Running" can comprise one or more of

Rotational Speed
Yarn Length
Slips (slow speed spindles)

Parameters associated with "Stopped" can comprise one or more of

Simple Break
Idles (Long duration breaks)
Startup breaks (breaks during machine start)
Mending time (duration of stop)

The at least one production measurement unit comprises a second sensor that is capable of determining at least one second sensor signal from which the production parameter can be determined, and a second signal processing unit for determining the production parameter from the second sensor signal.
It can be the case that the second sensor comprises at least one production sensor element arranged to measure the at least one production parameter at one spinning position of the spinning machine.
It can be the case that the second sensor is arranged to generate a single second sensor signal

from readings of a single one of the at least one production sensor elements, or
from readings of two or more of the at least one production sensor elements.

It can be the case that the second signal processing unit is arranged to determine one or more production parameters from one or more second sensor signals from a single spinning position.
It can be the case that the second signal processing unit is arranged to determine one or more production parameters from one or more second sensor signals from a plurality of spinning positions.
A first sensor (as part of a quality measurement assembly) and a second sensor (as part of a production measurement assembly) are arranged to observe the same strand of the strand like textile material being continuously transported within the spinning machine.
The quality measurement assembly can comprises a housing in which the first sensor is arranged, and mounting elements for attachment to the spinning machine, e.g. above a lappet hook.
The production measurement assembly can comprises a housing in which the second sensor is arranged, and mounting elements for attachment to the spinning machine, e.g. below a lappet hook.
The measurement system is configured such that the strand of the strand like textile material being continuously transported within the spinning machine passes through the first sensor, a lappet hook and the second sensor (3b). In particular it can be the case that the measurement system is configured such that the strand of the strand like textile material being continuously transported within the spinning machine passes through a quality measurement assembly, the lappet hook and a production measurement assembly.
The strand passes through the lappet hook after passing through the first sensor.
The strand passes through the second sensor after passing through the lappet hook.
In other words: The strand first passes through the first sensor, then passes through the lappet hook and afterwards passes through the second sensor.
The sensor is arranged to observe the strand of the strand like textile material being continuously transported within the spinning machine as it passes along the spinning path. The portion of the path of the stand extending between the delivery rollers and the lappet hook is called the spinning path. To observe means that the sensor is arranged to determine one or more sensor signals which in turn allow to determine production parameters and/or quality parameters of the strand.
The first sensor and the second sensor are arranged on a common carrier structure. The first sensor as part of a quality measurement assembly and the second sensor as part of the production measurement assembly are arranged on a common carrier structure. The common carrier structure is a physical structure that comprises the first and the second sensor, and that can be transported, handled, mounted to and dismounted from the machine as a single structure. The common carrier structure is arranged such that the first sensor is located above the lappet hook and the second sensor is located below the lappet hook.
It can be the case that the at least one quality parameter is derived from a measurement at least one of the following properties of the strand like textile material:

thickness;
reflectivity or occlusion of light in the visible and/or infrared and/or ultraviolet spectrum; and
mass per unit length or linear density.

Such properties and physical principles for measuring them are known, using optical, capacitive, ultrasound or displacement sensors etc.
It can be the case that the at least one quality parameter describes at least one of

impurities such as thick places, thin places, neps and its classifications based on the dimensions of the impurities; (and parameters thereof, such as length, thickness, ..and associated statistical values such as ...)
Variations of mass / thickness in short term and in long term with respect to time period;
Protruding fibres from the strand like textile material; and
the presence of foreign materials or vegetable matters, (and parameters thereof: frequency of occurrence, ...)

It can be the case that the at least one production parameter is derived from a measurement at least one of the following:

presence of the strand like textile material; and
rotational speed of the strand like textile material.

In a ring spinning machine, the rotational speed is the speed with which the traveller and the yarn rotate around the cop.
It can be the case that the at least one production parameter describes at least one of

breakage; (and associated statistical values such as ...);
rotational speed;
production; and
efficiency.

In the following and throughout this text, statements made with regard to a "sensor" or "sensors" in general apply to the abovementioned first sensors, second sensors and common sensors alike.
It can be the case that each sensor and an associated signal processing unit are physically arranged in a common carrier unit.
It can be the case that each sensor and an associated signal processing unit are physically arranged in separate carrier units.
It can be the case that a plurality of sensors and a single associated signal processing unit are physically arranged in a common carrier unit.
It can be the case that a plurality of sensors and a single associated signal processing unit are physically arranged in separate carrier units.
It can be the case that the measurement system comprises a plurality of sensors, each associated with a spinning position, these sensors being mounted on non-moving parts of the spinning machine.
It can also be the case that at least one sensor associated with a spinning position is mounted on non-moving parts of the spinning machine
It can be the case that the measurement system comprises a plurality of sensors, each associated with a spinning position, these sensors being mounted on moving parts of the spinning machine.
It can also be the case that at least one sensor associated with a spinning position is mounted on moving parts of the spinning machine
Such moving parts can be at least one of a ring rail, a lappet hook (pigtail hook) and a balloon control ring.
The sensors are arranged between front rollers of a drafting system and a ring of a spinning position of the spinning machine.
The sensors are arranged to measure yarn quality parameters between front rollers of a drafting system and a lappet hook (or yarn guide eyelet) of the spinning position.
It can be the case that the at least one quality measurement unit comprises a visual indicator of at least one quality parameter and/or production parameter or a deviation of such a parameter (from a reference value), and in particular wherein the visual indicator comprises at least one of

a lamp which can be operated to be lit in one or more colours that are indicative of one or more values of the parameter or deviation; or
a lamp which can be operated to be permanently lit or flashing, this being indicative of one or more values of the parameter or deviation; or
a lamp which can be operated to flash at different frequencies that are indicative of one or more values of the parameter or deviation; or
a display unit that is configured to display one or more values of the quality parameter.

It can be the case that the measurement system comprises a common display unit that is configured to display at least one of

one or more values of quality parameters from a plurality of quality measurement units; and
one or more combined values computed from the values of quality parameters from a plurality of quality measurement units, such combined values characterising an overall quality representing the plurality of quality measurement units and being, for example, computed by summing these values of quality parameters and/or by computing statistical measures from these values.

Communication between the display unit and the quality measurement units can be wire-based or wireless. The display unit can be implemented by a user interface of the measurement system itself or by a third-party handheld device such as a smart device interface like a smartphone or PDA or (tablet) computer.
It can be the case that the measurement system comprises a stopper arranged to perform at least one of holding and cutting the strand like textile material.
It can be the case that the measurement system is configured to actuate the stopper automatically or manually, in particular by means of a user interface of the measurement system itself or by a smart device interface that is in wireless communication with the measurement system.
It can be the case that the measurement system comprises or is connected to a monitoring unit that is configured to

continuously monitor at least one quality parameter of a continuously transported yarn in at least one spinning position of the spinning machine;
based on an on-line analysis of the monitored at least one quality parameter, identify a malfunction of the at least one spinning position or identify a substandard quality of roving material fed to the spinning position.

The monitoring unit can be a dedicated hardware unit, or it can be implemented as a software function. Such a software function can be executed in the signal processing unit and/or in the processed signal handling and communication system.
When a malfunction is identified, a signal - typically optical or acoustical - to an operator can be generated, and/or an error logfile can be updated with information about the malfunction.
It can be the case that the monitoring unit is configured to detect thin places, and to identify a malfunction of feeding bobbins when too many thin places occur.
It can be the case that the monitoring unit is configured to monitor a first and a second of two adjacent spinning positions, with a first quality parameter measured at the first spinning position and a second quality parameter measured at the second spinning position, and to identify a malfunction of drafting rollers for the two spinning positions when the first and the second quality parameter deviate in the same way.
It can be the case that the monitoring unit is configured to detect when the thickness of a yarn deviates from a reference thickness for a time that is longer than a time limit, and to identify a malfunction of the drafting system if this is detected.
It can be the case that the monitoring unit is configured to monitor one or more quality parameters and to identify a deviation of the yarn count on the basis of these quality parameters.
The monitoring unit can be arranged to operate as in the following embodiments:
When a plurality, and in particular each and every spindle of a spinning machine, is monitored through the online quality monitoring system, then the reason for deviation in quality parameters can be determined immediately as the spinning takes place. For example, machinery part defects in each spinning position will be identified easily by observing a quality parameter deviation. One example is identifying the reason for high thin places (that is, unacceptably thin places) in yarn: The reason for high thin places may be due to improper and irregular feeding of roving material. More particular, the reason can be an obstruction of the free rotation of a roving bobbin, which causes the feed package to produce thin places. When high thin places are detected by the quality measurement at a particular spinning position, the obstructing feeding bobbins can be identified.
A further quality parameter is hairiness, determined by a measurement of the fibres protruding over the textile material. One cause of deviations of hairiness are deviations in preparatory processes which cause more short fibres in the textile strand that enters the ring spinning machine, which in turn creates more hairiness of the yarn produced. In such a case, hairiness monitoring in the spinning machine can alert an operator, indicating deviations of hairiness exceeding a given limit.
It can happen that there is a problem in the drafting rollers of a ring spinning machine, which causes the quality of both the yarns delivered from the drafting zone to be affected. This is because the drafting system configuration is such that two top rollers are connected to each other. The drafting system serves two spinning positions. Hence, if one or more quality parameters of two adjacent delivery yarns both deviate from the norm, in particular in the same way, then the reason can be identified as being a malfunction of the drafting rollers of the drafting system. Typical deviations caused by the drafting system are thick places, thin places and unevenness.
A possible case of improper drafting is when two yarns combine with each other at delivery and get delivered as a single thick yarn. One or more quality properties of that thick yarn are of course quite different compared to other normal yarns. Such cases generally occur in ring frames, and such deviated yarns can be detected with online quality monitoring.
In some cases, if the count (the number of fibers) of the feed roving material is wrong, then the delivery yarn count will also become wrong. Such yarns with deviated counts will cause more cuts in further processes such as an auto winder and/or deteriorates the appearance of the fabric produced from the yarn. Such yarns with deviated counts will have a different quality characteristic compared to the normally running yarns in that ring frame. Such deviated yarns can be identified and corrected on-line and already in the spinning machine.
For example, if the count of yarn at a particular spinning position varies, then quality characteristics like unevenness and hairiness varies and will have significantly different values compared to the other spinning positions which are producing a correct yarn count. Such quality characteristic deviations can be considered to alert the operator so that he can check the count of the yarn delivered and also the count of the feed material, and initiate corrective action.
The subject matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings, which schematically show:

Figure 1: elements of a ring spinning machine and associated measurement and control systems;
Figure 2-7: arrangements of sensors for measuring quality and/or production parameters;
Figure 8: sensors comprising sensing elements;
Figure 9-12: arrangements of sensors and associated signal processing units;
Figure 13-14: different ways for mounting sensors;
Figure 15: a sensor with an indicator light;
Figure 16-18: different embodiments having display of quality parameters for a single sensor or a plurality of sensors;
Figure 19: a sensor with an associated stopper; and
Figure 20-21: sensors with an associated stopper linked to user interface devices.

The reference symbols used in the drawings, and their meanings, are listed in summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbols in the figures.
Figure 1 shows elements of a ring spinning machine and associated measurement and control systems. Of the ring spinning machine, for clarity only a few elements are shown: a number of spinning positions (which can also be called spinning stations), each with a spindle 7 carrying a spool on which a yarn 2 is wound on a bobbin or cop 4 by means of a traveller 6 spinning on a ring 5. The yarn 2 is delivered from a drafting system, of which only drafting rollers or delivery rollers 1 are shown in the figure. Other elements of a spinning position, not shown, are a lappet hook (or yarn guide eyelet or pigtail), balloon control ring (or balloon checking ring), ring rail, roller beam etc. The portion of yarn 2 between the delivery rollers 1 and the lappet hook is called the spinning path.
According to Figure 1 , in each of the spinning positions, a sensor 3 is arranged to observe the yarn 2 as it passes along the spinning path. To "observe" means that the sensor 3 is arranged to determine one or more sensor signals 17 which in turn allow to determine production parameters 18 and/or quality parameters 19 of the yarn. These parameters, referred to collectively as "processed signals" are determined from the sensor signal or signals 17 by one or more signal processing units 8. The processed signals from - typically a plurality of - signal processing units 8 are collected by a data collection unit 25 and further received by a processed signal handling and communication system 9 and can further be transmitted to an information system 10. The processed signals can be collected and stored by a data collection unit 25. The abovementioned elements and systems, their variations and combinations shall now be described in more detail.
Production parameters 18 are indicative of the quantity of yarn 2 that is produced. They typically describe whether a yarn 2 is present at all - if not, then production at the respective spinning position is interrupted and does not take place - or the speed of production, e.g. the speed of the yarn 2.
Production parameters 18 are, for example, a breaking of the strand like textile material, the time of breakage, associated time loss, repeated breaks, long duration breaks, breaks due to sudden movement of machine parts, delivery speed of the strand like textile material, rotational speed of the traveller of a spinning machine, efficiency, etc.
Quality parameters 19 are indicative of the quality of the yarn 2 as it passes by the sensor 3 when production takes place. They typically are based on optical or electrical properties of the yarn 2 and describe e.g. mass or thickness or reflectivity and further parameters and statistical values derived therefrom.
Quality parameters 19 are, for example, evenness, coefficient of variation, deviation rate, deviations from reference values, impurities like thick places, thin places, neps, hair properties, diameter, linear density, presence of foreign materials and vegetable matters etc.
A sensor 3 that determines quality parameters 19 can often also be used to detect the presence or absence of the yarn 2. It can therefore also provide information that allows to determine production parameters 18. Absence of the yarn typically indicates breakage of the yarn.
Figure 2 shows sections of three adjacent spinning positions, with in each case the yarn 2 passing through a quality measurement assembly 28, a lappet hook 23 and a production measurement assembly 27.
A sensor 3 together with an associated signal processing unit 8 forms a quality measurement unit 21 or a production measurement unit 20 or a common measurement unit 22.

A quality measurement unit 21, shown in Figure 3 , comprises a first sensor 3a that is capable of determining a first sensor signal 17a from which a quality parameter 19 can be determined, and a first signal processing unit 8a for determining the quality parameter 19 from the first sensor signal 17a. The first sensor 3a is shown to be arranged in the spinning path. The first sensor 3a is part of a quality measurement assembly 28. The quality measurement assembly 28 comprises a housing in which the first sensor 3a is arranged, and mounting elements for attachment to the spinning machine, e.g. above the lappet hook 23. Figure 4 shows a quality measurement unit 21 in which a single first signal processing unit 8a is arranged to process first sensor signals 17a from two or more first sensors 3a. One or more or all of the first sensors 3a can each comprise one or more quality sensor elements for measuring quality. If there is more than one quality sensor element in a first sensor 3a, their output can be combined within the first sensor 3a to form a combined first sensor signal 17a, or each of them can provide a separate first sensor signal 17a. The first signal processing unit 8a can be arranged to process signals from a single quality sensor element, or from two or more quality sensor elements from a single first sensor 3a, or from more than one first sensors 3a.
A production measurement unit 20, shown in Figure 5 , comprises a second sensor 3b that is capable of determining a second sensor signal 17b from which a production parameter 18 can be determined, and a second signal processing unit 8b for determining the production parameter 18 from the second sensor signal 17b. The second sensor 3b is shown to be arranged to observe the yarn in the region of the balloon, that is, below the lappet hook 23. The second sensor 3b is part of a production measurement assembly 27. The production measurement assembly 27 comprises a housing in which the second sensor 3b is arranged, and mounting elements for attachment to the spinning machine, e.g. below the lappet hook 23. Figure 6 shows a production measurement unit 20 in which a single second signal processing unit 8b is arranged to process second sensor signals 17b from two or more second sensors 3b. One or more or all of the second sensors 3b can each comprise one or more production sensor elements for measuring production. If there is more than one production sensor element in a second sensor 3b, their output can be combined within the second sensor 3b to form a combined second sensor signal 17b, or each of them can provide a separate second sensor signal 17b. The second signal processing unit 8b can be arranged to process signals from a single production sensor element, or from two or more production sensor elements from a single second sensor 3b, or from more than one second sensors 3b.
A common measurement unit 22, shown in Figure 7 , according to an embodiment which does not fall within the scope of the claims, comprises a common sensor 3c that is capable of determining a common sensor signal 17c from which a production parameter 18 and a quality parameter 19 can be determined, and a common signal processing unit 8c for determining the production parameter 18 and the quality parameter 19 from the common sensor signal 17c. The common sensor 3c is part of a common measurement assembly 29. The common measurement assembly 29 comprises a housing in which the common sensor 3c is arranged, and mounting elements for attachment to the spinning machine, e.g. above the lappet hook 23.
One or more or all of the common sensors 3c can each comprise one or more common sensor elements for measuring quality and production. If there is more than one common sensor element in a common sensor 3c, their output can be combined within the common sensor 3c to form a common sensor signal 17c, or each of them can provide a separate common sensor signal 17c. The common signal processing unit 8c can be arranged to process signals from a single common sensor element, or from two or more common sensor elements from a single common sensor 3c, or from more than one common sensors 3c. If there are two or more common sensor elements, then one or more can be replaced by quality sensor elements and one or more can be replaced by production sensor elements.

When referring to sensors 3 and signal processing units 8, it is understood that these can stand, respectively, for such first, second and common sensors and such first, second and common signal processing units.
Figure 8 shows a sensor 3, which can be a first, a second or a common sensor, wherein the common sensor embodiment does not fall within the scope of the claims, as shown in Figures 3-7 , with one sensor element 31 (left) and with two or more sensor elements 31 (middle and right). Depending on which type the sensor 3 is, the sensor elements 31 are quality sensor elements, production sensor elements or common sensor elements.
Figures 9-12 show arrangements of sensors 3 and associated signal processing units 8. The sensors are shown as pairs of first sensors 3a (as part of quality measurement assemblies 28) and second sensors 3b (as part of production measurement assemblies 27) arranged to observe the same yarn 2. These first and second sensors 3a, 3b can have their signals processed by separate first and second signal processing units 8a, 8b or by a common signal processing unit 8c, which will be referred to collectively as signal processing units 8. Figure 9 shows sensors 3 and signal processing units 8 arranged pairwise, for each spinning position on a common carrier unit 26 or even in a common housing, e.g. within a quality measurement assembly 28 or a production measurement assembly 27. Figure 10 shows sensors 3 and signal processing units 8 being arranged pairwise, for each spinning position in a separate housing or on a separate carrier unit 26. Figure 11 shows a single signal processing unit 8 that is common to a plurality of sensors 3, i.e., that processes the sensor signals from this plurality of sensors 3. This plurality of sensors 3 and the signal processing unit 8 are arranged on the same carrier unit 26 or in the same housing. Figure 12 also shows a single signal processing unit 8 that is common to a plurality of sensors, but with the signal processing unit 8 arranged in a housing or on a carrier unit 26 that is separate from the plurality of sensors 3.
A carrier unit 26 is a physical unit that comprises one or more units, such as sensors 3 or assemblies and/or signal processing units 8, and that can be transported, handled, mounted to and dismounted from the machine as a single unit.
Signal processing units 8, one or more data collection units 25, and associated processed signal handling and communication systems 9 can be arranged in different ways, for example:

arranged on a common carrier or in a common housing,
arranged in separate housings or on separate carriers.

Communication between the different units or systems can be by wire-bound or wireless communication technologies.
Likewise, the processed signal handling and communication system 9 and information system 10 can be arranged on common or separate carriers or housings, and can communicate with by wire-bound or wireless communication technologies. Furthermore, the processed signal handling and communication system 9 and information system 10 can be arranged on the same carrier or in the same housing together with one or more signal processing units 8.
The processed signal handling and communication system 9 is programmed and configured to handle processed signals from a plurality of signal processing units 8 of one or more spinning machines. These signal processing units 8 are part of production measurement units 20 and/or quality measurement units 21.
The processed signal handling and communication system 9 stores the processed signals, and in particular the production parameters 18 and the quality parameters 19, obtained from the signal processing units 8. The processed signals can be stored in compressed format, for example by storing only information regarding a total or an average number of faults for a unit of production, rather than parameters of each fault.
The information system 10 is used for compiling, processing, displaying and printing information obtained from the processed signal handling and communication system 9. The information system can generate reports with accumulated data on production parameters 18 and quality parameters 19. Reports can comprise live on-line information or stored information past periods of time. The information system can store a large amount of historical data for viewing the history of quality and production parameters of multiple ring frames for each spindle position.
The information system 10 can be used for an operator to input data and/or commands for controlling the system, that is, the spinning machine and/or the processed signal handling and communication system 9 and/or the signal processing units 8. This can be done by the information system 10 communicating with the signal processing units 8 (of production measurement units 20 and/or quality measurement units 21 and/or common measurement units 22) through the processed signal handling and communication system 9.
Commands for controlling the system can include requirements input by an operator, such as control parameters, set points for detecting faults, generating alerts etc.
The information system 10 can also be arranged to inform and alert an operator or other user about the production and quality parameters, deviations noticed etc. through one or more of various communication tools like emails, SMS and internet based messaging and social networking tools.
Typically, a plurality of sensors, production measurement units 20 or quality measurement units 21 are arranged at adjacent spinning positions. This can be done by mounting them on separate carriers for each spinning position. Alternatively, this can be done by mounting them on a common carrier that spans a plurality of spinning positions. The same variations are possible when they comprise signal processing units 8.
Figures 13-14 show different ways for mounting sensors 3 on the spinning machine, that is, on moveable parts or on fixed, i.e. non-moveable parts. Figure 13 shows a sensor 3 attached to and moving with a lappet hook 23 of a spinning position. Figure 14 shows a sensor 3 attached to a roller beam 24, which is a non-moveable part. The same mounting options - i.e., moveable or fixed - are possible with combinations of sensors 3 and signal processing units 8 instead of just sensors 3.
Figure 15 shows a display of quality parameters and/or production parameters in or near a sensor 3 and/or its associated signal processing unit 8. Each sensor can be equipped with a light emitting element such as a lamp 14 or LED which can be lit at least in one colour. The lamp 14 indicates, e.g., deviations from set limits or reference values of the strand like textile material for different quality parameters in single and multiple colours. In general, values and/or deviations of a quality parameter 19 and/or a production parameter 18 can be indicated by operating the lamp 14 in different ways. Such different ways can be: lighting the lamp in different colours, lighting the lamp permanently or flashing the lamp; flashing the lamp at different frequencies, and combinations thereof.
Figure 16 show a display of quality parameters and/or production parameters for a single sensor or a plurality of sensors by means of a display unit 12 arranged on or near a sensor 3 and/or its associated signal processing unit 8. A button 13 or touch sensitive area or other input element can be used to select individual quality parameters and/or parameter values derived therefrom, such as statistical values, to be displayed. Optionally, such an input element can be used to select individual sensors 3 or groups of sensors 3 to which the displayed values relate.
Figure 17 show a display of the quality parameters and/or production parameters and other values mentioned in Figure 16 , for a single sensor or a plurality of sensors, but on a display unit 12 that is separated from the sensors 3. The display unit 12 can communicate with the signal processing units 8 directly or through the processed signal handling and communication system 9 or the information system 10, by means of wire bound or wireless communication technologies.
Figure 18 show a configuration as in Figure 17 , wherein the display unit 12 is a commercially available smart device interface, a smart device interface 16 being typically a handheld device such as PDA or smartphone or mobile phone or tablet computer, and typically communicating by wireless means.
Figure 19 shows a sensor 3 with an associated stopper 11. A stopper 11 is used to stop the production of the strand like textile material when there is a deviation of a quality parameter 19 that crosses a predetermined limit, that is, becomes larger than the limit or smaller than the limit, depending on whether it is an upper or a lower limit.
In general, a deviation of a parameter, be it a measured or a derived quality or production parameter, can be processed in the following manner in order to detect a fault or more generally an event. Such a fault or event can influence a derived parameter, such as a fault count, statistical measures, etc., and/or generate a signal to the operator and/or trigger a stopper, etc. An event can be detected when the parameter exceeds an upper limit, or - what is mathematically equivalent - the deviation of the parameter from a reference value in the positive direction is larger than an upper deviation limit. Likewise, an event can be detected when the parameter falls below a lower limit, or - what is mathematically equivalent - the deviation of the parameter from a reference value in the negative direction is larger than a lower deviation limit.
Such limits for parameters or for deviations can be set by an operator, or be based on statistical analysis using measurements from a plurality of spinning positions of a spinning machine, or be based on statistical analysis using measurements from a plurality of spinning machines. For example, for a particular parameter a long term (e.g. over several minutes or hours or more of a production run with nominally the same parameters) average value is determined from such measurements. The limits can be derived from this average value manually or automatically, e.g. by multiplying the long term average with a tolerance factor. Depending on whether the limit is an upper or a lower limit, the tolerance factor is larger or smaller than one.
The stopper 11 can be a cutter which cuts the strand like textile material, or a gripper arranged to hold the strand like textile material. A decision for stopping the strand like textile material can be taken automatically, for example by the signal processing unit 8 or the processed signal handling and communication system 9. Alternatively, a command for stopping can be manually triggered by an operator by means of a display unit 12 or smart device interface 16 as described herein.
Figures 20-21 show sensors with associated user interface devices, these devices being a dedicated user interface 15 or a commercially available smart device interface 16. These user interface devices can communicate directly with a sensor 3 or its associated signal processing unit 8, or via a processed signal handling and communication system 9 or an information system 10.
In embodiments, which do not fall within the scope of the claims, in which, for each spinning position, a common measurement unit 22 is present, or in which only single first sensors 3a or only second sensors 3b are arranged to observe the same yarn 2 are present, corresponding display elements or devices as described in relation with Figures 15 to 21 , that is, lamps 14 with one or more colours, display units 12, user interfaces 15 and smart device interfaces 16, can be configured to indicate information relative to parameters determined from measurements of the sensors 3 that are present.
While the invention has been described in present embodiments, it is distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practised within the scope of the claims.

Claims

A ring spinning machine comprising a measurement system, the ring spinning machine comprising a plurality of spinning positions, the measurement system comprising
• a plurality of quality measurement units (21) each configured to continuously measure at least one quality parameter (19) of at least one strand of the strand like textile material being continuously transported within the spinning machine,
wherein each of the plurality of quality measurement units (21) comprises a first sensor (3a) that is capable of determining at least one first sensor signal (17a) from which the quality parameter (19) can be determined, and a first signal processing unit (8a) for determining the quality parameter (19) from the first sensor signal (17a),
wherein the measurement system comprises
• at least one production measurement unit (20) each configured to continuously measure at least one production parameter (18) that characterises a running status of at least one strand of the continuously transported strand like textile material,
wherein each of the plurality of spinning positions is associated with an individual production measurement unit (20),
wherein the at least one production measurement unit (20) comprises a second sensor (3b) that is capable of determining at least one second sensor signal (17b) from which the production parameter (18) can be determined, and a second signal processing unit (8b) for determining the production parameter (18) from the second sensor signal (17b),
wherein the first sensor (3a) and the second sensor (3b) are arranged to observe the same strand of the strand like textile material being continuously transported within the spinning machine,
characterised in that the measurement system is configured such that the strand of the strand like textile material being continuously transported within the spinning machine passes through the first sensor (3a), a lappet hook (23) and the second sensor (3b),
wherein said strand passes through the first sensor before passing through the lappet hook,
wherein said strand passes through the second sensor after passing through the lappet hook,
wherein the first sensor (3a) and the second sensor (3b) are arranged on a common carrier structure.
The ring spinning machine according to claim 1, wherein each of the plurality of spinning positions is associated with an individual quality measurement unit (21).
The ring spinning machine according to one of the preceding claims,
wherein the first sensor (3a) comprises at least one quality sensor element arranged to measure the at least one quality parameter (19) at one spinning position of the spinning machine,
in particular wherein the first sensor (3a) is arranged to generate a single first sensor signal (17a)
• from readings of a single one of the at least one quality sensor elements, or

• from readings of two or more of the at least one quality sensor elements.
The ring spinning machine according to claim 3, wherein the first signal processing unit (8a) is arranged to determine one or more quality parameters (19) from one or more first sensor signals (17a) from at least one of a single spinning position and a plurality of spinning positions.
The ring spinning machine according to claim 1 to 4, wherein the second sensor (3b) is arranged to generate a single second sensor signal (17b)
• from readings of a single one of at least one production sensor elements, or

• from readings of two or more of the at least one production sensor elements.
The ring spinning machine according to one of the preceding claims, wherein the at least one quality parameter (19) is derived from a measurement of at least one of the following properties of the strand like textile material:
• thickness;

• reflectivity or occlusion of light in the visible and/or infrared and/or ultraviolet spectrum; and

• mass per unit length or linear density.
The ring spinning machine according to one of the preceding claims, wherein the at least one production parameter (18) is derived from a measurement of at least one of the following:
• presence of the strand like textile material; and

• rotational speed of the strand like textile material.
The ring spinning machine according to one of the preceding claims, wherein each sensor (3) of the first and second sensors
and an associated signal processing unit (8) are physically arranged in a common carrier unit (26) or separate carrier units (26).
The ring spinning machine of one of the preceding claims, wherein a plurality of sensors (3) of the first and second sensor
and a single associated signal processing unit (8) are physically arranged in a common carrier unit (26) or separate carrier units (26) for the sensors.
The ring spinning machine of one of claims 1 to 9, comprising a plurality of first and second sensors (3), each associated with a spinning position, these sensors (3) being mounted on non-moving parts of the spinning machine.
The ring spinning machine of one of claims 1 to 9, comprising a plurality of sensors (3), each associated with a spinning position, these sensors (3) being mounted on moving parts of the spinning machine.
The ring spinning machine according to one of the preceding claims, wherein the first sensors (3) are arranged to measure yarn quality parameters between front rollers of a drafting system and a lappet hook of the spinning position.
The ring spinning machine according to one of the preceding claims, wherein the at least one quality measurement unit (21) comprises a visual indicator of at least one quality parameter (19) and/or production parameter (18) or a deviation of such a parameter, and in particular wherein the visual indicator comprises at least one of
• a lamp (14) which can be operated to be lit in one or more colours that are indicative of one or more values of the parameter or deviation; or

• a lamp (14) which can be operated to be permanently lit or flashing, this being indicative of one or more values of the parameter or deviation; or

• a lamp (14) which can be operated to flash at different frequencies that are indicative of one or more values of the parameter or deviation; or

• a display unit (12) that is configured to display one or more values of the quality parameter (19).
The ring spinning machine according to one of the preceding claims, comprising a common display unit (12) that is configured to display at least one of
• one or more values of quality parameters (19) from the plurality of quality measurement units (21); and

• one or more combined values computed from the values of quality parameters (19) from a plurality of quality measurement units (21), such combined values characterising an overall quality representing the plurality of quality measurement units (21) and being, for example, computed by summing these values of quality parameters (19) and/or by computing statistical measures from these values.
The ring spinning machine according to one of the preceding claims, comprising a monitoring unit that is configured to
• continuously monitor at least one quality parameter (19) of a continuously transported yarn (2) in at least one spinning position of the spinning machine;

• based on an on-line analysis of the monitored at least one quality parameter (19), identify a malfunction of the at least one spinning position or a substandard quality of roving material fed to the spinning position,
in particular wherein the monitoring unit is configured to
- detect thin places, and to identify a malfunction of feeding bobbins when too many thin places occur;

- to monitor a first and a second of two adjacent spinning positions, with a first quality parameter measured at the first spinning position and a second quality parameter measured at the second spinning position, and to identify a malfunction of drafting rollers for the two spinning positions when the first and the second quality parameter deviate in the same way;

- to detect when the thickness of a yarn (2) deviates from a reference thickness for a time that is longer than a time limit, and to identify a malfunction of the drafting system if this is detected; and/or

- to monitor one or more quality parameters (19) and to identify a deviation of the yarn count on the basis of these quality parameters (19).