GB2183260A

GB2183260A - A spinning machine

Info

Publication number: GB2183260A
Application number: GB08625061A
Authority: GB
Inventors: Joachim Rohner
Original assignee: Zinser Textilmaschinen GmbH
Current assignee: Oerlikon Textile GmbH and Co KG
Priority date: 1985-10-18
Filing date: 1986-10-20
Publication date: 1987-06-03
Also published as: GB8625061D0; FR2588887A1; IT8622008A0; IT1198038B

Abstract

At each spinning station 10 of a yarn doubling and spinning machine, two fibre bundles 17, 17' run from a drafting mechanism 11 to a combining point 19 from which they are twisted together to form a yarn 23. Each spinning station 10 is provided with a sensor 21 which responds to the breakage of either of the two fibre bundles 22, 22' and also to breakage of the yarn 23 formed from them. To achieve reliable response by the sensor 21 during the spinning of any yarns, the sensor 21 monitors the normal path of one of the two fibre bundles 22, 22' above the combining point 19 or the normal path of the yarn 23 below the combining point 19 for the presence of the respective fibre bundle or yarn, or its sensing region extends from the normal path of the yarn 23 below the combining point 19 beyond the normal position of the combining point 19 towards the drafting mechanism 11. The sensors may be mechanical feelers or as shown photo-electric devices. <IMAGE>

Description

SPECIFICATION A spinning machine The invention relates to a spinning machine, for instance of the ring spinning type having a plurality of spinning stations at each of which two fibre bundles issuing from a drafting mechanism and spaced apart next to each other as still untwisted fibre slivers run to a combining point and downstream thereof are twisted together to form the yarn which runs to a spindle or the like for imparting twist to the yarn, each spinning station being provided with a sensor which responds to breakage of either fibre bundle and to breakage of the yarn.

Such a spinning machine produces yarns from two respective fibre bundles which run to a combining point from which they are twisted together to form a single yarn. The fibre slivers can be composed of any noncontinuous fibres, preferably of combed wool.

The yarn can be twisted by conventional means, for example by means of a spindle which coaxially penetrates a spinning ring on which a traveller dragged by the yarn can revolve. However, it is also possible to provide other devices for producing the twist and for winding the yarn, for example a rotating spinning can, a flyer spindle or the like.

Each working station of the spinning machine at which a yarn is produced is called a spinning station. With a known spinning machine of this type (DE-OS 30 21 614) each spinning station is provided with a breakage monitor having a rotatable arm resting on the combining point as sensor. If a fibre bundle breaks, then the arm tilts downwards and triggers a following yarn breakage by means of a clamping member which clamps the yarn and is rigidly connected to the arm, but this is undesirable because the travel of the remaining fibre bundle at the spinning station is not generally interrupted by the breakage of only one of the two fibre bundles. A yarn of smaller thickness and, in the case of equal portions, of half thickness would then be spun.

This defective point could easily lead to yarn breakages and to defective goods during subsequent processing of the yarn. This known breakage monitor has the advantage that it requires only a single mechanical sensor, but as this mechanical sensor formed by the arm rests on the combining point, it can influence it and the yarn, for example move it downwards and increase the risk of breakage, in particular with fine yarns.

A spinning machine of this type is also known (DE-OS 30 28 453) in which a single sensor is also provided, but this sensor senses, at a distance below the combining point of the two fibre bundles, a property of the yarn descending from the combining point which alters noticeably when the yarn is spun from only one of the two fibre bundles. This property may relate to its mass/length which is to be measured capacitively or to its thickness which is to be measured photo-optically.

However, this is on the assumption that the yarn is very uniform, so this measuring method has only restricted applications. There is also a risk that fibre fly settling on the measuring device can lead to faulty measurements.

According to a first aspect of the invention, there is provided a spinning machine as defined in the appended claim 1.

According to a second aspect of the invention, there is provided a spinning machine as defined in claim 2.

According to third and fourth aspects of the invention, there are provided spinning machines as defined in claims 12 and 13, respectively.

It is thus possible to provide a spinning machine in which only a single breakage sensor is required per spinning station, but which does not increase the risk of breakage of the fibre bundles or of the yarn and which allows the spinning of any yarns, even of very irregular yarns, without disadvantage.

In such a machine, the sensor does not need to respond sensitively to a changing property of the yarn, but only to the presence or absence of the yarn or of the respective fibre bundle on its normal path of travel. The yarn can therefore have any properties, in particular can also be very irregular and can be composed of any fibres, for example of natural fibres (for example wool) and/or synthetic fibres and/or other fibres, and of long or longer fibres and/or short fibres, for example of cotton fibres or similar short fibres. This sensor is therefore insensitive or only slightly sensitive to fibre fly and can easily be designed in such a way that an undesirable amount of fibre fly cannot collect on it and can also be easily cleaned of any fibre fly which might be present, for example by means of a conventional travelling blower.This sensor can preferably operate without contact, but it is also possible to scan the presence or absence of the yarn or of the fibre bundle on the respective normal path of travel by means of a mechanical sensor as this does not lie on the combining point of the two fibre bundles but only needs to contact the yarn or the fibre bundle lightly on the side at a distance from the combining point so that it does not increase the risk of breakage.

The sensing region of the sensor can extend beyond the normal position of the combining point towards the drafting mechanism.

The sensor can thus monitor not only the normal path of the yarn but also the normal paths of both fibre bundles simultaneously, and this further simplifies the work of the sensor and makes it particularly reliable. The combining point and portions of the two fibre bundles and of the yarn are normally or always located in the sensing region of the associated sensor and a particularly large amount of fibre material is therefore always or normally located in its sensing region. Fibre material of the yarn or of at least one fibre bundle still located on the normal path can even be located in the sensing region of the sensor if the yarn and/or a fibre bundle temporarily moves out of the sensing region of the sensor owing to marked deflections of the combining point. The sensing of normally moving fibre material is thus simplified by the sensor.This can also allow a reduction in the sensitivity of the sensor.

The sensor is preferably a photoelectric sensor, in particular a photoelectronic sensor, particularly preferably a light scanner. It may also advantageously contain at least one lens.

However, other sensors, in particular sensors operating without contact, can also be used, such as capacitive sensors of the like.

Sensors operating without contact can be constructed without difficulty in a particularly simple manner in such a way that they do not tend to accumulate fibre fly and can easily be cleaned, in particular by blowing using travelling blowers. In a preferred embodiment, the photoelectric sensor is designed as a light barrier, whether as a single path light barrier, a reflex light barrier or other light barrier. With a single path light barrier, the light transmitter and the light receiver face one another, whereas in reflex light barriers the light transmitter and the light receiver are arranged next to one another and are directed towards a reflector facing them at a distance.

However, it is also possible to design the photoelectric sensor in a different manner, for example as a reflex scanner. When it is designed as a reflex scanner, it also has a light transmitter and a light receiver.

The photoelectric sensor also has the advantage of not requiring mechanically moving parts and of being structurally simple, inexpensive and extremely reliable in operation when produced.

As a relatively long period of time can often elapse before a yarn breakage is removed, or the yarn breakage is often removed only on completion of a take-off and during this period of time the fibre slivers still issuing from the drafting mechanisms of the respective spinning station are not twisted into yarn, it is advantageous if a yarn breakage also occurs as a result of a breakage of a fibre bundle and the further delivery of the fibre slivers from the drafting mechanism is preferably interrupted automatically at the respective spinning station. This can be achieved if a yarn severing device for clamping, severing, tearing or the like of the yarn and/or a roving stopping device is controlled by a breakage signal.The yarn severing device serves to sever the yarn which is still present at the respective spinning station after the occurrence of a breakage of one of the two fibre bundles. This severing can be carried out, for example mechanically using a cutting device or electrically using a glowing wire or in other suitable ways, for example by clamping the yarn since a breakage occurs as the result of yarn clamping because it is no longer conveyed to the winding device. A roving stopping device stops the travel of the two fibre slivers (rovings, slubbings) running to the drafting mechanism of the respective spinning station in any suitable way, for example by clamping, opening the drafting mechanism or the like.

The invention will be further described by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a schematic sectional front view of a spinning station of a ring spinning machine not shown in further detail, some of the electronic equipment of this machine for automatic interruption of spinning of the yarns during response by photoelectric sensors also being shown in a block diagram; Figure 2 shows a schematic plan view of the photoelectric sensor in the spinning station according to Figure 1; Figure 3 shows a variation of the sensor according to Figure 2; Figure 4 shows a sectional view of a variation of the spinning station according to Figure 1; Figure 5 shows a magnified partial section through Figure 4, viewed along the line 5-5, no parts located beneath the combining point 19 being shown;; Figure 6 shows a schematic sectional front view of a spinning station of a ring spinning machine not shown in further detail, a part of the electronic equipment of this machine for the automatic interruption of yarn spinning during the response of photoelectric sensors also being shown in a block diagram; and Figure 7 shows a schematic plan view of the photoelectric sensor in the spinning position according to Figure 6 in a magnified view.

The spinning station 10 shown in section in Figure 1 of a ring spinning machine has a drafting mechanism 11 containing several roller pairs for drafting two fibre slivers 17, 17' running next to one another, spaced apart, only the delivery roller pair 14 of this drafting mechanism 11 being shown. The lower roller 15 of this delivery roller pair in spinning machinery of the conventional type may be formed by a lower cylinder extending almost over the entire length of the respective side of this spinning machine, an upper roller 16 being pressed onto the lower cylinder at each spinning station.The two individual fibre slivers 17, 17' passing through the drafting mechanism are guided at a lateral distance from one another by sliver guides (not shown) and, after leaving the delivery roller pair 14, run to a combining point 19 located close above a photoelectric sensor 21 forming a one-way light barrier (Figure 2). Two still untwisted fibre bundles 22, 22' issuing from the delivery roller pair 14 are twisted together to form a yarn 23 from the combining point 19. This yarn 23 passes through the sensor 21 arranged stationarily at a distance below the combining point 19 on the normal path existing when two fibre bundles 22, 22' are present and then immediately passes through a yarn severing device 24 which may be designed, for example, as a cutting device with two blades.This yarn severing device 24 may be electrically actuated and the yarn 23 is cut through as the result of each actuation. This actuation is triggered by the sensor 21 when it senses a breakage.

Providing the yarn severing device 24 is not actuated, the yarn 23 passes through it without being cut by it. The yarn 23 then passes through a yarn guide 25 arranged at a distance above a spindle and from this, while forming a balloon of thread, to a rotating spindle 26 on which there is detachably placed a bobbin 27 on which the yarn 23 is wound to form a yarn package 29. On this path from the yarn guide 25 to the spindle 26, the yarn 23 passes through a traveller 30 which is dragged by the yarn and revolves on a spinning ring 31 coaxially penetrated by the spindle 26. This spinning ring 31 is located on an annular bench 32 which performs lifting movements to lay the yarn 23 on the bobbin 27 to form the package 29.

If one of the two fibre bundles 22, 22' tears, then the other fibre bundle performs a lateral movement and the yarn 23 therefore passes away from the light beam of the light barrier 21 and is now twisted alone to form a yarn. This respective remaining fibre bundle is designated by 22a and 22a' in the drawings and forms a yarn of correspondingly reduced thickness.

In the embodiment shown in Figure 2 of the photoelectric sensor 21 as a light barrier, its light transmitter 42 and its light receiver 44 are arranged on the two arms of a horizontal frame 41 which is C-shaped in the plan view.

The light transmitter 42 and the light receiver 44 are arranged in corresponding openings in the frame 41 forming a common housing for them. The light transmitter 42 and light receiver 44 project only Slightly with their lenses beyond the frame 41 having a smooth external periphery so that the frame, including the light transmitter 42 and light receiver 44 arranged in it has, all round, a smooth external periphery which does not produce projections for the settling of fibre fly and therefore this entire sensor 21 is insensitive to dirt and, in particular, does not tend to retain fibre fly.

Also, it can be cleaned simply and easily owing to its smooth surface, whether mechanically or by blowing with a conventional travelling blower of the type known for pneumatic cleaning of spinning machinery.

The light receiver 44 containing, for example, a photodiode and lens receives the light beam produced by the light transmitter 42 comprising an incandescent lamp, light diode or the like and a lens in a straight beam path and converts it into a corresponding electric signal. Providing the light beam is attenuated by the yarn 23, the electric output signal of the light receiver which is amplified in an amplifier 43 lies below the threshold value of a threshold value detector 33 connected downstream of the amplifier 43 so that it does not transmit an output signal and the severing device 25 is not actuated.However, if a remaining fibre bundle such as 22a or 22a' falls away from the light beam of the light barrier 21 owing to a breakage of the other respective fibre bundle, or also in the case of a breakage of the yarn 23, then the radiation energy received by the light receiver 44 increases and, as described in more detail below, an electric breakage signal, which activates the severing device 24 for severing the fibre bundle 22a or 22a' existing as a yarn and can optionally signal the breakage to an operator or to an automatic thread piercing carriage for removal, is therefore triggered.

The light barrier 21 can also be designed as a reflection light barrier, in other words the light transmitted by the light transmitter 42 is reflected on a reflector on the region of the frame 41 opposing it and is received by a light receiver arranged next to it. The received light intensity increases accordingly if the yarn 23 passes out of the light beam owing to the breakage of one of the fibre bundles 22, 22'.

The threshold value of the detector 33 can be adjusted by means of a threshold value selector 34 which is provided in common for all spinning stations on the respective machine or on the respective lengthwise side of the machine so that the threshold value of each threshold value detector 33 can be adjusted to the thickness or the count of the respectively spun yarn. Some further threshold value detectors 33 which are connected to other spinning stations on this spinning machine are also shown in Figure 1.

The spinning machine can have, for example, several hundred spinning stations.

The threshold value detector 33 is designed in such a way that it transmits an output signal providing the output signal amplified in the amplifier 43 of the associated light receiver 44 exceeds its given threshold value but does not transmit an output signal from the amplifier 43 falls below the set threshold value. The apparatus can preferably be arranged such that the exceeding of the threshold value is signalled only when it has been exceeded continuously for a predetermined short period of time which is selected in such a way that it cannot be caused by chance deflections and vibrations of the yarn 23. This period of time can also be adjusted by the threshold value selector 34.The output signal from the threshold value detector 33 forms the breakage signal of the respective spinning station and is converted and amplified in an amplifier and pulse forming stage 36 and then supplied to the yarn severing device 24 for triggering a cutting process so that the yarn 22a' or 22a still present is cut by the yarn severing device 24 and the spinning of the yarn is thus interrupted.

Instead of being designed as a light barrier, the sensor 21 can preferably have other designs in many cases, for example as a reflex scanner of the type illustrated with reference to an embodiment in Figure 3. In this case, the photosensitive sensor 21 has a light transmitter 42 and a light receiver 44 which are arranged laterally next to one another on one arm of an angle girder 41' fixed stationarily on the frame of the spinning machine in such a way that the light receiver 44 invariably senses the yarn 23 when it enters the light beam of the light transmitter 42 to such an extent that the light receiver 44 responds to the light thus reflected to it from the yarn.

In this case, the amplifier 43 can preferably have a pulse forming stage and a subsequent inverter in such a way that the threshold value detector 33 transmits a breakage signal for actuating the severing device 24 whenever a fibre bundle 22 or 22' has broken and so that the yarn formed by the remaining fibre bundle 22a' or 22a passes out of the region of action of the reflex scanner 21.

Instead of arranging the photoelectric sensor in such a way that it scans the normal path of the yarn 23 without contact, that is in the presence of both fibre bundles 22, 22' at a distance below the combining point 19, it can also be arranged in such a way that it scans the normal path of one of the two fibre bundles 22 or 22' for defects in this fibre bundle 22 or 22'. This is illustrated schematically in Figure 4 with reference to an embodiment in which a sensor 21 scans the normal path of the fibre bundle 22 at a distance above the combining point 19, a mechanical sensor 21 being arranged here instead of a photoelectric sensor.A photoelectric sensor, particularly preferably a light barrier or a reflex scanner or, for example, even a photoelectric sensor which detects the fibre bundle 22 only illuminated by the normal light from the internal lighting of the respective machine room can obviously be used instead of the mechanical sensor 21, the sensor not having a light transmitter in the latter case, or it can be any other suitable sensor which senses whether the fibre bundle 22 is missing from the normal track scanned by it.If this fibre bundle 22 is missing from its normal path of travel, then a breakage signal is triggered in this embodiment in that the mechanical sensor 21 actuates an electric switch 55 which can preferably be only a contact switch which signals each time the sensor 21 comes into contact with it, more specifically in this embodiment a direct electric breakage signal to a severing device 24 which, when excited by this signal, severs the respective remaining yarn 22a or 22a'.

In this embodiment, this sensor 21 has an arm 57 which is mounted rotatably on a holder 56 arranged rigidly on the frame of the spinning machine (not shown) and which forms the mechanical sensor 21. It is spring loaded in the direction of the arrow A by a spring 58 and takes up the fibre bundle 22 at a distance above the combining point 19 in a fork 59 arranged at the free end. The spring 58 is only very weak so that the arm 57 rests with only a slight force on the fibre bundle 22 and does not affect the travel thereof.

However, if the fibre bundle 22 or the yarn 23 breaks, this arm 57 is pressed by the spring 58 into the position shown in chain dot lines in Figure 5 until it contacts the contact switch 55 so that this switch 55 then triggers a breakage signal signalling the breakage for actuating the severing device 24 for severing the remaining fibre bundle 22a and optionally also for actuating an alarm for calling an operator or a yarn piecing carriage.If on the other hand the fibre bundle 22 and the yarn 23 do not break but rather the fibre bundle 22', then the path of travel of the fibre bundle 22 shifts from its normal path onto the path allocated to the now remaining fibre bundle 22a so that this remaining fibre bundle 22a forming a yarn also causes the sensor 21 to pivot into the position shown in chain dot lines in Figure 5 in which the arm 57 again rests on the contact switch 55 and thus also triggers the severing device 24 for severing the remaining fibre bundle 22a.

The mechanical sensor 21 can optionally also be used in Figure 1 instead of the photoelectric sensor 21 or a photoelectric sensor 21 can be used in the embodiment according to Figures 4 and 5 instead of the mechanical sensor 21 and the electric switch connected to it.

The spinning station 10 shown in section in Figure 6 of a ring spinning machine differs from the one shown in Figure 1 substantially as follows. The sensor 21 which operates without contact and which can also preferably be a photoelectric sensor is arranged in Figure 6 in such a way that it monitors not only the normal path of the yarn 23 below the combining point 19 for the presence of the yarn 23 but also that the sensing region of this sensor 21 also extends beyond the normal position of the combining point 19 towards the drafting mechanism 11 so that it also monitors the normal paths of the two fibre bundles 22, 22' adjacent to the combining point 19. If the two fibre bundles 22, 22' are present, the combining point 19 is therefore continuously or nor mally inside the sensing region of the photoelectric sensor 21 forming a one-way light barrier in this embodiment (Figure 7).The two fibre bundles 22, 22' as well as the yarn 23 therefore pass through the sensing region of the stationarily arranged sensor 21 on the tracks which are normal in the presence of the two fibre bundles 22, 22' and then pass through the yarn severing device 24 which can be designed, for example, as a cutting device with two blades.

If one of the two fibre bundles 22, 22' tears, the other fibre bundle performs a sideways movement and this bundle as well as the yarn 23 therefore leave the light beam of the light barrier 21 and now together form a remaining fibre bundle 22a or 22a' and a yarn of correspondingly reduced thickness.

In the embodiment illustrated in Figure 7 of the photoelectric sensor 21 from Figure 6 as a light barrier its light transmitter 42 and its light receiver 44 are again arranged on the two arms of a horizontal frame 41 which is Cshaped in the plan view, as with the embodiment according to Figure 2, and the statements made in this respect there apply here.

The light receiver 44 containing, for example, a photodiode and a lens receives the light beam produced by a light transmitter 42 comprising an incandescent lamp, light diode or the like and a lens in a straight beam path and converts it into a corresponding electric signal. If the light beam is attenuated by the yarn 23 and/or at least one fibre bundle 22 or 22', the electric output signal of the light receiver 44 which is amplified in an amplifier 43 iies below the threshold value of a threshold value detector 33 connected downstream of the amplifier 43 so that the threshold value detector 33 does not transmit an output signal and the severing device 24 is not actuated.However, if a fibre bundle such as 22 or 22 breaks, then the remaining fibre bundle such as 22a or 22a' and therefore the yarn now formed from it alone passes out of the light beam of the light barrier 21 and the radiation energy received by the light receiver 44 increases and an electric breakage signal is triggered which activates the severing device 24 for severing the fibre bundle 22a or 22a' existing as yarn and can optionally signal the breakage to an operator or to an automatic thread piecing carriage for removal. A breakage of the yarn 23 also triggers a breakage signal.

The light barrier 21 can also be designed as a reflection light barrier, ie the light transmitted by the light transmitter 42 is reflected to a reflector at the region of the frame 41 facing it and is received by a light receiver arranged next to it. The received light intensity increases accordingly when the yarn 23 passes from the light beam owing to the breakage of either fibre bundle 22, 22'. Other sensors operating without contact are also possible. The statements made with respect to Figure 1 concerning the threshold value detectors 33 and the yarn severing device 24 also apply here. The remaining yarn is similarly cut as the result of the breakage of a fibre bundle 22 or 22'.

Claims

1. A spinning machine for the spinning of yarns, comprising a plurality of spinning stations at each of which two respective textile fibre bundles issuing from a drafting mechanism and spaced apart next to one another as still untwisted fibre slivers run to a combining point and downstream thereof are twisted together to form the yarn which runs to means for imparting twist to the yarn, each spinning station being provided with a sensor which responds to the breakage of any one of the two fibre bundles and also to breakage of the yarn formed therefrom, the sensor being arranged to monitor either the normal path of one of the two fibre bundles above the combining point or the normal path of the yarn below the combining point for the presence of the respective fibre bundle or yarn and, in the event of sudden absence of the monitored fibre bundle or yarn from the normal path during operation, to trigger a breakage signal.

2. A spinning machine, for the spinning of yarns, comprising a plurality of spinning stations, at each of which two respective textile fibre bundles issuing from a drafting mechanism and spaced apart next to one another as still untwisted fibre slivers run to a combining point and downstream thereof are twisted together to form the yarn which runs to means for imparting twist to the yarn, each spinning station being provided with a sensor which responds to the breakage of any one of the two fibre bundles and also to the breakage of the yarn formed therefrom, the sensor being arranged for contact-free sensing and being arranged to monitor the normal path of the yarn below the combining point for the presence of the yarn and having a sensing region which extends beyond the normal position of the combining point of the two fibre bundles toward the drafting mechanism.

3. A spinning machine as claimed in claim 1, in which the sensor is arranged for contactfree sensing.

4. A spinning machine as claimed in any one of the preceding claims, in which the sensor is a photoelectric sensor.

5. A spinning machine as claimed in claim 4, in which the sensor is a light barrier.

6. A spinning machine as claimed in claim 4, in which the sensor is a reflex scanner.

7. A spinning machine as claimed in any one of the preceding claims, in which the sensor is provided with a threshold value detector arranged to respond to variations in the output signal from the sensor occurring as the result of breakage of a fibre bundle by transmitting a breakage signal.

8. A spinning machine as claimed in claim 7, in which the threshold value detector is arranged to signal a breakage of a fibre bundle only if the sensor output exceeds or remains below a threshold value continuously for a predetermined period of time.

9. A spinning machine as claimed in any one of the preceding claims, including a yarn severing device and/or a roving stopping device arranged to be controlled by the sensor.

10. A spinning machine as claimed in claim 1, in which the sensor is a mechanical sensor.

11. A spinning machine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

12. A yarn spinning machine comprising at least one spinning station arranged to receive two spaced textile fibre bundles and to combine the bundles into a yarn at a combining point prior to twisting, the or each spinning station comprising means for imparting twist to the yarn and a sensor for monitoring a normal path of one of the bundles upstream of the combining point or of the yarn downstream of the combining point and for producing a signal in response to the absence of the bundle or yarn from the normal path thereof.

13. A yarn spinning machine comprising at least one spinning station arranged to receive two spaced textile fibre bundles and to combine the bundles into a yarn at a combining point prior to twisting, the or each spinning station comprising means for imparting twist to the yarn and a non-contact sensor for monitoring the presence of the yarn along a normal path downstream of the combining point and having a sensing region which extends upstream of a normal position of the combining point.