CH713692A1 - Feeder. - Google Patents

Abstract

The present invention relates to a feed device (4) for feeding fiber flakes in a spinning preparation machine with a feed roller (6), a feed trough (5) and an open electrical circuit with a voltage source (14), wherein the circuit can be closed by a metal part contaminating the fiber flakes is. According to the invention, it is proposed that the open ends of the circuit are formed by the feed roller (6) and the feed trough (5).

Description

Description: The present invention relates to a feed device for feeding fiber flakes into a spinning preparation machine with a feed roller, a feed trough and an open electrical circuit with a voltage source, the circuit being closable by a metal part contaminating the fiber flakes.

From GB 465,899 a spinning preparation machine is known which has means for recognizing metal parts in the fiber material. These means comprise a pair of rollers through which the fiber material runs. The roles are spaced from each other. Furthermore, the rollers are arranged in an electrical circuit, the circuit being closed when a metallic foreign body closes the gap between the two rollers. When the circuit is closed, the fiber material is stopped or moved backwards.

The disadvantage of this solution is that a pair of rollers is required, which on the one hand impairs the fiber flow and on the other hand has to be cleaned and maintained regularly.

The object of the present invention is therefore to provide a feed device that recognizes metal parts without the need for an extra pair of rollers.

The object is achieved by a feed device with the features of the independent claim.

A feed device for feeding fiber flakes into a spinning preparation machine is proposed. The spinning preparation machine can be a card, a card or a cleaner. The feed device has a feed roller, a feed trough and an open electrical circuit with a voltage source. The circuit can be closed by a metal part contaminating the fiber flakes. Conversely, a closed circuit indicates a metal part contaminating the fiber flakes.

According to the invention, the open ends of the circuit are formed by the feed roller and the feed trough. So there are two already existing elements of the feed device used for the detection of metal parts. No other mechanical parts that affect fiber flow and need to be cleaned and maintained are required.

It is advantageous if the feed trough is electrically insulated from the feed roller. An open circuit can then be formed in which the feed trough and the feed roller are the open ends. The bearing of the feed roller is preferably the insulator. In this way, the insulation can be accomplished with very little effort. The entire bearing of the feed roller and / or a bearing ring of the bearing particularly preferably consist of an electrically insulating plastic. Depending on the size of the feed roller and the mechanical requirements, one of the two variants can prove to be the more advantageous.

In an advantageous development of the feed device, the feed trough is assigned an elastic lip. The elastic lip forms a gap between itself and the feed roller. Furthermore, the feed trough has a contact surface and means are provided for detecting a contact between the elastic lip and the contact surface. If the elastic lip is deformed by a foreign body, it comes into contact with the contact surface if the foreign body and thus the elastic deformation are large enough. The contact and thus also the foreign body are recognized by the means for recognizing a contact. Due to the contact of the elastic lip with the contact surface, non-metallic foreign bodies are also recognized.

[0010] Alternatively, the means for detecting a contact can have a piezoelectric element. Piezoelectric elements are inexpensive, reliable and largely maintenance-free. The piezoelectric element can be attached to the elastic lip and / or to the contact surface. When there is contact between the elastic lip and the contact surface, pressure is then exerted on the piezoelectric element, which in turn results in an electrical voltage that is sensed by a sensor system.

It is also advantageous if the means for detecting a contact comprise electrical insulation between the elastic lip and the contact surface. A voltage is present between the elastic lip and the contact surface and the contact between the elastic lip and the contact surface is recognized by closing a circuit. This makes it easy and inexpensive to detect contact between the elastic lip and the contact surface, the electronics required for this in particular being inexpensive and robust.

Advantageously, the electrical potential of the feed trough is equal to the electrical potential of the contact surface and the electrical potential of the feed roller is equal to the electrical potential of the elastic lip, but different from the electrical potential of the feed trough. A voltage source can thus be used to detect both a metal part between the feed roller and the feed trough, and therefore also a contact between the elastic lip and the contact surface caused by a foreign body. The voltage generated by the voltage source is preferably between 1.5 V and 32 V, particularly preferably between 12 V and 28 V. On the one hand, these voltages are easy to generate and, on the other hand, they do not require extremely sensitive detectors. Furthermore, the voltages are small enough not to pose a risk to the health of the operating personnel should there be contact with one or both of the electrodes.

CH 713 692 A1 It is also advantageous if the electrical potential of the feed trough is equal to the electrical potential of the contact surface and the feed trough, the feed roller and the elastic lip each have a different electrical potential. Although three different electrical potentials are necessary, in contrast to the above, contact between the elastic lip and the feed roller caused by a metal part can also be detected. Such a metal part can therefore already be detected if it has not yet deformed the elastic lip to such an extent that it comes into contact with the contact surface. The voltages, i.e. the potential differences, are again in the ranges mentioned above.

The elastic lip and the contact surface form an opening to a cavity, which among other things enables the mobility of the elastic lip. So that this cavity is not dirty, a seal is advantageously arranged between the elastic lip and the contact surface. This seal is deformable to such an extent that it can be overpressed when the elastic lip is deformed and thus does not hinder the electrical contact between the elastic contact surface or the pressure on the piezoelectric element.

It is advantageous if a spacer bar is arranged between a base body of the feed trough and the elastic lip. This makes it possible to achieve an optimal distance between the base body and the elastic lip for clamping the fiber material. So that this distance can be adjusted for different fiber lengths, the spacer bar is preferably interchangeable and / or adjustable. In the case of particularly large fiber lengths, above about 28 mm, the spacer bar can then be completely dispensed with.

It is also advantageous if the elastic lip is made of steel, in particular chromium steel, since these materials have good elasticity and good spring strength. Chromium steel is also corrosion-resistant. A wall thickness of the elastic lip at its front end is preferably between 1.0 mm and 4.0 mm, particularly preferably between 1.5 mm and 2.0 mm, since this provides the necessary spring strength.

[0017] The contact surface is advantageously assigned to a support strip. The support strip is arranged at such a distance from the elastic lip that the distance can be closed by an elastic deformation of the elastic lip. If there were no support strip, a very large foreign body could deform the elastic lip so much that it leaves the elastic area and then does not return to its previous shape. The support bar prevents this and thus enables a longer lifespan of the elastic lip. A particularly suitable material for the support strip is aluminum, since it has great dimensional stability with a low weight.

It is advantageous if the feed trough is divided into at least two segments along a working width of the feed trough, each segment being assigned an elastic lip. This simplifies the adjustment of the gap created by the elastic lip, since it is no longer necessary to set a constant gap width over the entire working width.

Advantageously, each segment is assigned a piezoelectric element or the elastic lips assigned to the individual segments are electrically insulated from one another and assigned to separate circuits. It is therefore possible to recognize a foreign body separately for each segment. If this is displayed to the operating personnel, the search for the foreign body is simplified, the foreign body can consequently be removed more quickly and production can be continued again more quickly.

It is also advantageous if the feed device comprises an acoustic and / or visual alarm which is triggered when there is contact between the elastic lip and the contact surface and / or the circuit between the feed roller and the feed trough and / or the elastic lip is closed. The alarm is therefore triggered when a metal part contaminating the fiber flakes and / or another foreign body is detected. This draws the operator's attention to the metal part or the foreign body. The operating personnel can then stop production and / or remove the metal part or the foreign body.

Finally, it is advantageous if the feed device comprises a control device which interrupts the feeding of the fiber flakes when there is contact between the elastic lip and the contact surface and / or a closed circuit between the feed roller and the feed trough and / or the elastic lip and the feed roller stops. With modern feed devices, it is possible that the surface of the feed roller moves only 10 mm from the time a metal part or foreign body is detected to a standstill. This largely prevents damage to the feed roller and the feed trough. After the feed roller has come to a standstill, the control device preferably rotates it back by a predetermined or predeterminable angle. This angle is or is set so that the metal part or the foreign body reaches an area from which it can be easily removed by the operating personnel.

The feed device is designed according to the preceding description, wherein the features mentioned can be present individually or in any combination.

[0023] Further advantages of the invention are described in the following exemplary embodiments. Show it:

1 is a schematic side view of a card,

CH 713 692 A1

2 shows a schematic side view of a feed device,

3 shows a schematic cross section through a bearing of a feed roller,

4 shows a schematic cross section through a further bearing of a feed roller,

5 shows a schematic side view of a further feeding device,

6 shows a schematic side view of a further feeding device,

Fig. 7 is a schematic side view of another feed device and

Fig. 8 is a schematic front view of a food trough.

1 shows a schematic side view of a card 1. The fibers in card 1 are transported from left to right. A fiber mat 2 first runs over a feed plate 3 and then passes into a feed device

4. The feed device 4 has a feed trough 5 which interacts with a feed roller 6. The fiber mat 2 clamped between the feed trough 5 and the feed roller 6 is then fed to a licker-in roller 7.

From the lickerin roller 7, the nonwoven fabric continues on a reel 8 and is further processed between the reel 8 and a cover 9 shown here very schematically. The nonwoven fabric is then removed from a doffer roll 10 and passed on to a compression unit 11, where it is compressed into a card sliver 12.

Fig. 2 shows a schematic side view of a feed device 4 according to the invention. The feed device 4 can be part of the card 1 shown in Fig. 1, but it can also be part of a card or a cleaner. The feed device 4 has a feed trough 5 and a feed roller 6. In addition, part of the licker-in roller 7 is also shown.

The feed trough 5 and the feed roller 6 are arranged as open ends in an open circuit. The feed roller 6 can be electrically connected, for example, via its axis. The circuit further comprises a voltage source 13 and a current measuring device 14. If the gap between the feed trough 5 and the feed roller 6 is closed by a metal part contaminating the fiber flakes, the circuit is also closed. A current then flows, which is detected by the current measuring device 14. A current flow detected by the current measuring device 14 thus indicates a metal part between the feed trough 5 and the feed roller 6.

In order to indicate the current flow in the circuit and thus the detection of the metal part, the current measuring device 14 is connected to an acoustic and / or optical alarm 15 which indicates to the operating personnel the metal part.

Advantageously, the current measuring device 14 is also connected to a control device 16 which stops the feed roller 6 when a metal part is detected so that the metal part does not penetrate further and does not cause any major damage. It is particularly advantageous if the control device 16 rotates the feed roller 6 after it has been stopped so far back that the metal part comes out from under the feed trough 5 and can easily be removed by the operating personnel.

In order to keep the circuit open, the feed trough 5 and the feed roller 6 must be electrically insulated from one another. This insulation can take place via an electrically insulating bearing 17 of the feed roller 6, which is shown in cross section in FIG. 3. In the embodiment of FIG. 3, the entire bearing 17 of the feed roller 6 consists of an electrically insulating plastic. The axis 18 of the feed roller 6 is consequently electrically isolated from the bearing 17 and the other parts of the feed device 4.

In the alternative embodiment of FIG. 4, there is only one bearing ring 19 of the bearing 17 made of an electrically insulating plastic, while the main body 20 of the bearing 17 can also be electrically conductive. The axis 18 of the feed roller 6 is also electrically isolated from the bearing 17 and the other parts of the feed device 4 in this case.

In the following description of alternative exemplary embodiments, the same reference numerals are used for features which are identical in their design and / or mode of operation and / or at least comparable in comparison to other exemplary embodiments. Unless these are explained again in detail, their design and / or mode of operation corresponds to the design and mode of operation of the features already described above.

In the embodiment shown in FIG. 5, only part of the feed roller 6 is shown so that the details of the feed trough 5 can be made more visible. The electrical connection to the feed roller 6 is also shown only very schematically, but it can take place via the axis of the feed roller 6 as above.

5 has a base body 21, which is partially protected from wear by a protective plate 22. A spacer bar 23 is also arranged on the base body 21 in order to allow an optimal distance between the base body 21 and an elastic lip 24. The spacer bar 23 is designed to be interchangeable so that it can be adapted to the respective fiber length. With very long fibers, the spacer bar 23 can even be omitted entirely.

CH 713 692 A1 The elastic lip 24 is arranged such that fibers can be clamped between it and the feed roller 6. On the side of the elastic lip 24 facing away from the feed roller 6, a support strip 25 is also arranged. The elastic lip 24 can be elastically deformed at least until it touches the support bar 25. A further deformation of the elastic lip 24, for example due to a hard foreign body in the fiber material, is prevented by the support strip 25. The elastic lip 24 is therefore in particular not deformed into an area in which permanent deformation occurs. A return of the elastic lip 24 to its original shape and position is always guaranteed.

In order to protect the intermediate space 26 between the elastic lip 24 and the support strip 25 from soiling, in particular due to fiber fly, an easily deformable seal 27 is arranged between the elastic lip 24 and the support strip 25.

In order to detect a hard foreign body that presses the elastic lip 24 against a contact surface 28 of the support strip 25, the elastic lip 24 and the support strip 25 are also arranged in the circuit. For this purpose, an electrical insulation 29 first isolates the elastic lip 24 from the support strip 25.

The electrical circuit in this embodiment is constructed so that the voltage source 13 in addition to the earth (0 V) provides a positive (+ U) and a negative (-U) voltage. The amounts of the positive and negative voltages do not have to be the same and other obvious interpretations of the voltage source are also possible. The positive voltage is applied to the elastic lip 24, the negative voltage is applied to the feed roller 6 and the support strip 25 and the base body 21 or the protective plate 22 of the feed trough 5 are connected to the earth. A metal part contaminating the fiber flakes, which brings the feed trough 5 into contact with the feed roller 6, closes a circuit, as described above, and the current flow is detected by the current measuring device 14. If, on the other hand, the elastic lip 24 is deformed, for example by a hard foreign body, to such an extent that it contacts the contact surface 28 of the support strip 25, then another circuit is closed and current flows, which another current measuring device 30 measures. Even a smaller metal part, which has not yet been able to make contact between the feed roller 6 and the base body 21 of the feed trough 5, but which makes contact between the feed roller 6 and the elastic lip 24, can be detected. A circuit is closed, which results in a current flow through the current measuring device 14 and the further current measuring device 30. A current flow through the two current measuring devices 14 and 30 consequently indicates a metal part between the feed roller 6 and the elastic lip 24.

A representation of the alarm 15 and the control device 16 has been omitted in this figure for the sake of clarity. However, the measured values of both current measuring devices 14 and 30 are preferably used by the control device 16 to trigger an alarm 15 and to stop and / or reverse the feed roller 6. For example, the alarm can indicate, in different tones, colors or other representations, in which area a metal part and / or foreign body has been detected. The angle by which the feed roller is moved back after a stop can also be selected depending on the area in which the metal part or the foreign body has been detected. For example, the angle for a metal part that has caused contact between the feed roller 6 and the base body 21 of the feed trough 5 must be smaller than the angle for a foreign body that first brought the elastic lip 24 into contact with the contact surface 28 of the support strip 25 Has.

In an embodiment not shown here, the feed roller 6 and the elastic lip 24 have the same electrical potential. A simpler voltage source 13 can therefore be used. A measurement of an electrical contact between the feed roller 6 and the elastic lip 24, triggered by a smaller metal part, is then no longer possible.

In the embodiment shown in FIG. 6, the contact between the elastic lip 24 and the contact surface 28 is detected by a piezoelectric element 31. In this case, the piezoelectric element 31 is arranged on the contact surface 28 of the support strip 25, but it can also be arranged on the elastic lip 24. When there is contact between the elastic lip 24 and the contact surface 28, pressure is exerted on the piezoelectric element 31, which leads to an electrical voltage between two electrodes of the piezoelectric element 31. This electrical voltage is measured and the contact is thus detected.

The circuit for detecting a metal part between the feed roller 6 and the feed trough 5 is carried out analogously to that shown in FIG. 2. The alarm 15 (not shown here) and the control device 16 are advantageously also connected to the measuring device of the piezoelectric element 31, so that a differentiated alarm is triggered and / or the feed roller can be optimally stopped and / or retracted.

In this embodiment, the feed trough 5 is shown without a spacer bar, which is optimal for particularly long fiber lengths.

In the feed trough 5 shown in FIG. 7, the spacer bar 23 is designed as an adjustable linkage 32. It can therefore be set to different fiber lengths without time-consuming modifications.

Furthermore, no support strip is provided in the exemplary embodiment in FIG. 7. The contact surface 28 is arranged on an electrically insulating holder 33. This also means that there is no separate insulation of the elastic lip 24

CH 713 692 A1 required. As a possible electrical circuit, the base body 21 or the protective plate 22 of the feed trough 5 and the elastic lip 24 are connected to the earth. The feed roller 6 and the contact surface 28 have a different potential. Both metal parts that make contact between the feed roller 6 and the base body 21 or the protective plate 22 of the feed trough 5 or the elastic lip 24 and foreign bodies that press the elastic lip 24 against the contact surface 28 can be detected.

Finally, FIG. 8 shows a schematic front view of a feed trough 5. The elastic lip 24 is divided into four segments 24.1, 24.2, 24.3 and 24.4. A different number of segments is of course also possible. The individual segments are shorter than a single elastic lip 24 and can thus be better adjusted across their width.

[0048] The individual segments of the elastic lip 24 are also electrically insulated from one another. For this purpose, an insulation layer 34 is attached in the area in which they adjoin one another, of which only one has been provided with a reference symbol for the sake of clarity. The individual segments are each connected to the voltage source via a current measuring device. In the case of a foreign body or metal part in the fiber mat, it can thus be recognized in which segment this foreign body or metal part is located. This is preferably indicated to the operating personnel so that the operating personnel can immediately search for the foreign body in the correct segment and then remove it.

The present invention is not limited to the illustrated and described exemplary embodiments. Modifications within the scope of the claims are possible as well as a combination of the features, even if these are shown and described in different exemplary embodiments.

Reference symbol list [0050]

teasel

Fiber mat

feed plate

feeder

feed trough

feed roll

licker

drummer

cover

doffer

compacting unit

Kardenband

voltage source

Current measurement device

alarm

control device

camp

axis

bearing ring

main body

body

mudguard

CH 713 692 A1

spacer bar

Elastic lip

24.1-24.4 segments of the elastic lip

supporting strip

gap

poetry

contact area

Electric Isolation

Further current measuring device

Piezoelectric element

linkage

holder

insulation layer

Claims (15)

claims 1. Feeding device for feeding fiber flakes in a spinning preparation machine with a feed roller (6), a feed trough (5) and an open electrical circuit with a voltage source (14), the circuit being closable by a metal part contaminating the fiber flakes, characterized in that the open ends of the circuit are formed by the feed roller (6) and the feed trough (5). 2. Feeding device according to the preceding claim, characterized in that the feed trough (5) is electrically insulated from the feed roller (6), the bearing (17) of the feed roller (6) preferably being the insulator and particularly preferably the entire bearing (17 ) of the feed roller (6) and / or a bearing ring (19) of the bearing (17) consist of an electrically insulating plastic. 3. Feeding device according to one of the preceding claims, characterized in that the feed trough (5) is assigned an elastic lip (24), the feed trough (5) has a contact surface (28) and means for detecting contact between the elastic lip (24 ) and the contact surface (28) are provided. 4. Feeding device according to claim 3, characterized in that the means for detecting a contact comprise an electrical insulation (29) between the elastic lip (24) and the contact surface (28), a tension between the elastic lip (24) and the Contact surface (28) is present and the contact between the elastic lip (24) and the contact surface (28) is recognized by closing a circuit. 5. Feeding device according to one of the preceding claims, characterized in that the electrical potential of the feed trough (5) is equal to the electrical potential of the contact surface (28) and the electrical potential of the feed roller (6) is equal to the electrical potential of the elastic lip (24) , but is different from the electrical potential of the feed trough (5). 6. Feeding device according to one of the preceding claims, characterized in that the electrical potential of the feed trough (5) is equal to the electrical potential of the contact surface (28) and the feed trough (5), the feed roller (6) and the elastic lip (24) each have a different electrical potential. 7. Feeding device according to claim 3, characterized in that the means for detecting a contact have a piezoelectric element (31), the piezoelectric element (31) being attached to the elastic lip (24) and / or to the contact surface (28) , 8. Feeding device according to one of the preceding claims, characterized in that a seal (27) is arranged between the elastic lip (24) and the contact surface (28). 9. Feeding device according to one of the preceding claims, characterized in that a, preferably exchangeable and / or adjustable, spacer bar (23) is arranged between a base body (21) of the feed trough (5) and the elastic lip (24). 10. Feeding device according to one of the preceding claims, characterized in that the elastic lip (24) consists of steel, in particular chromium steel, and a wall thickness of the elastic lip (24) at its front end preferably between 1.0 mm and 4.0 mm, particularly preferably between 1.5 mm and 2.0 mm. CH 713 692 A1 11. Feeding device according to one of the preceding claims, characterized in that the contact surface (28) is associated with a support strip (25), the support strip (25) preferably being made of aluminum. 12. Feeding device according to one of the preceding claims, characterized in that the feed trough (5) is divided into at least two segments (24.1-24.4) along a working width of the feed trough (5) and each segment (24.1-24.4) has an elastic lip (24 ) assigned. 13. Feeding device according to claim 12, characterized in that each segment (24.1-24.4) is assigned a piezoelectric element (31) or the elastic lips (24) assigned to the individual segments (24.1-24.4) are electrically insulated from one another and are assigned to separate circuits , 14. Feeding device according to one of the preceding claims, characterized in that the feeding device (4) comprises an acoustic and / or visual alarm (15) which is triggered when contact between the elastic lip (24) and the contact surface (28) takes place and / or the circuit between the feed roller (6) and the feed trough (5) and / or the elastic lip (24) is closed. 15. Feeding device according to one of the preceding claims, characterized in that the feeding device (4) comprises a control device (16) which upon contact between the elastic lip (24) and the contact surface (28) and / or a closed circuit between the Feed roller (6) and the feed trough (5) and / or the elastic lip (24) interrupts the feeding of the fiber flakes, the feed roller (6) stops and preferably then turns the feed roller (6) back by a predetermined or predeterminable angle. CH 713 692 A1 C \! CH 713 692 A1 IF ^{3 H}