EP0038449A1 - Electrical stop motion for a textile machine - Google Patents

Abstract

In textile machines fed with fibre slivers, such as e.g. drawframes, immediate stopping of the machine is required in case of a sliver breakage before or on the feed table. This requirement is fulfilled using the inventive stop motion apparatus quickly and reliably, by tilting a pan arranged beneath each normally running fibre sliver and which does not contact such fibre sliver. The reaction time of the stop motion apparatus can be shortened by providing a heavy body on, and movable with respect to, the pan, the body being e.g. in the form of a steel ball. Since the pan in its working position does not contact the normally running fibre sliver, slivers of improved quality are produced and contamination of the stop motion apparatus is avoided.

Description

The present invention relates to an electrical storage device for a textile machine fed with fiber tapes, in particular a draw frame, with a rocker that can be tilted between a working position and a storage position per incoming fiber band, the tilting of which is caused by the running out of the belt and causes the actuation of an electrical contact .

In the case of textile machines fed with slivers, such as draw frames, a larger number of slivers are pulled out of supply cans and fed to the drafting system by means of a dining table, where the slivers are carefully lined up. If even a single sliver is missing for any reason, e.g. because the corresponding feed can is empty or because the sliver feed is interrupted, the machine must be switched off immediately so that no defective sliver, i.e. a sliver with too low a number, is produced . This shutdown must also be done very quickly so that the end of the sliver cannot run into the drafting system. If the end of the band is still above the dining table, the new beginning of the band can be connected to the end by hand, which is indicated by "turning" happens so that there is no faulty spot in the sliver leaving the machine. On the other hand, if this is not the case, i.e. if the end of the sliver reaches or even crosses the drafting system before the sliver breaks and the machine is switched off, then a certain sliver with a lower fiber content is inevitably produced, which must be eliminated if you do not take the risk the production of faulty finished products (fabrics, knitted fabrics, etc.). Furthermore, the then necessary _E is infädelungsoperation the new beginning of the strip in the drafting system easy technically against the above-described simpler "Andre Hung" much more complicated and time consuming.

Numerous parking devices for such machines have been developed over the course of time, and the constant increase in working speeds has brought about an increase in the requirements for the parking device, particularly with regard to the reaction speeds.

The various known devices of this type, one of which is representative of the device according to _DE here - _PS is mentioned 909'550, operate on the principle of the _A BTA stung of the sliver by means of a sensing lever. In the absence of the strap, the lever from the working position in which it relies on the continuous sliver, bstellage into an _A, usually by a tilting movement, move, this movement being used for the actuation of an electric Abstellkontaktes.

In the aforementioned solution of the German Patent No. 909'550 the swept _F is aserband by means of a rocker-like, single hinged flap which operates the stop switch and is supported from below by means of a tongue on the continuous sliver. Similar solutions with direct scanning of the fiber sliver passing through are very well known, and the belt is also scanned from above instead of from below, as in the patent mentioned here. An example of such a solution with scanning from above may be mentioned, for example, that of US Pat. No. 3,305,896.

• a) Bildung von sogenannten "Faserschnäuzen" am Abtasthebel. In den Randzonen des abtastenden Organs, welche vom durchlaufenden Band nicht mehr genügend gestreift werden, d.h. dort wo der Anpressdruck am kleinsten ist, können sich Randfasern festankern, wozu die kleinste unvermeidliche Rauhigkeit genügt, und mit der Zeit zu Faseransammlungen führen. Diese lösen sich von Zeit zu Zeit und laufen dann zusammen mit dem Band, womit ein Fehler im produzierten Band erzeugt wird.
• b) Solche vom Material gestreifte Abtastorgane sind der Verschmutzung durch im Material selber enthaltene Faser- und Staubteilchen unterworfen, welche die Zuverlässigkeit der Abstellvorrichtung gefährden können. Da die Faserbänder selber meistens keine grossen Zugkräfte vertragen können, ist man gezwungen, auch die sie abtastenden Organe als mit kleinen Kräften arbeitende Organe zu gestalten. Kleine Aenderungen in den Reibungsbedingungen des Tasthebels können also bereits die Ansprechempfindlichkeit der Abstellvorrichtung beeinflussen, womit der Abstellvorgang unsicher wird.
• _c) Abhängigkeit vom verarbeitenden Material, insbesondere von dessen Volumen. Bekanntlich können gleich schwere Faserbänder sehr stark, als Folge z.B. der Kräuselung und des Parallelisierungsgrades der Fasern, aber auch der Verdichtung, die sie bei der Ablage in die Kanne erfahren haben, im Querschnitt, bzw. im Volumen, variieren. Es folgt, dass bei bänderabtastenden Abstellvorrichtungen sich unter Umständen eine Anpassung an das zu verarbeitende Material als nötig erweist, damit optimale Arbeitsverhältnisse gesichert werden können.

All of these known solutions have major disadvantages stemming from direct scanning. These include:

• a) Formation of so-called "fiber snouts" on the scanning lever. In the marginal zones of the scanning organ, which are no longer sufficiently touched by the continuous belt, i.e. where the contact pressure is the smallest, marginal fibers can anchor firmly, for which the smallest inevitable roughness is sufficient, and lead to fiber accumulation over time. These loosen from time to time and then run together with the tape, creating an error in the tape produced.
• b) Such scanning elements streaked by the material are subject to contamination by fiber and dust particles contained in the material itself, which can endanger the reliability of the parking device. Since the fiber tapes themselves usually cannot tolerate large tensile forces, one is forced to design the organs that scan them as organs that work with small forces. Small changes in the friction conditions of the feeler lever can therefore already affect the response sensitivity of the parking device, making the parking process unsafe.
• _c ) Dependence on the processing material, in particular on its volume. It is known that fiber ribbons of the same weight can vary greatly in cross-section or in volume, for example as a result of the crimping and the degree of parallelization of the fibers, but also due to the compression that they experienced when they were deposited in the can. It follows that, in the case of belt-scanning shutdown devices, it may be necessary to adapt to the material to be processed, so that optimal working conditions can be ensured.

The object of the present invention is to propose an electrical storage device of the type mentioned at the outset, in which the above-mentioned disadvantages of the known devices are eliminated and which above all ensures absolute operational reliability.

This object is achieved with an electrical storage device according to claim 1.

Claims 2, 3, 5 and 6 show embodiments of the parking device according to the invention which represent particularly favorable solutions with regard to the response speed of the parking device.

Claim 4 corresponds to a very favorable embodiment of the electrical parking device with regard to its operational reliability, while claim 7 relates to a particularly simple and inexpensive variant of the parking device.

• _Fig. 1 eine perspektivische Teildarstellung des Einlauftisches einer Strecke mit der erfindungsgemässen Abstellvorrichtung;
• Fig. 2 den Einlauftisch der Fig. 1 im Grundriss;
• Fig. 3a bis 3c die schematischen Darstellungen der erfindungsgemässen Abstellvorrichtungen während drei verschiedener Arbeitsphasen der Vorrichtung;
• _Fig. 4 eine Variante der Abstellvorrichtung in perspektivischer Darstellung;
• Fig. 5 eine weitere Variante der Abstellvorrichtung im Seitenriss, und
• Fig. 6 die Abstellvorrichtung der Fig. 5 im Aufriss.

The invention will now be explained with reference to some usfüh- illustrated _A approximately examples closer. It shows:

• _F ig. 1 is a partial perspective view of the infeed table of a draw frame with the parking device according to the invention;
• Fig. 2 shows the inlet table of Figure 1 in plan.
• 3a to 3c the schematic representations of the parking devices according to the invention during three different working phases of the device;
• _F ig. 4 shows a variant of the parking device in a perspective view;
• Fig. 5 shows another variant of the storage device in side elevation, and
• Fig. 6 shows the parking device of Fig. 5 in elevation.

The infeed table 1 (FIGS. 1 and 2) of a draw frame (not shown in FIGS. 1 and 2 and shown here as representative of a whole series of textile machines) has the task of a plurality of fiber tapes 2 to the work organs of the textile machine, for example the drafting system in the case of a line, orderly, ie parallel to each other. For this purpose, pairs of rollers 4/5 are attached to the side edges 3 of the table diverging towards the machine, the lower roller 4 of each pair being fixedly mounted on the edge of the table 3 and being driven by means not shown (eg toothed belt). The upper roller 5 is normally designed as a pressure roller, ie it is freely movable perpendicularly to the lower roller 4, is pressed against it either by its own weight or by special pressing means (not shown) and is driven by the lower roller 4 only as a result of friction. Under each roller pair 4/5 is respectively arranged a spinning pot 6, from which the fiber tape 2 is drawn out through the roller pair _4/5. The inventive electric _A b-adjusting device now ensures that each individual, the _E is monitored inlauftisch 1 supplied fiber strip 2 so that the textile machine is stopped immediately if even a single fiber strip 2 is not properly supplied to the working elements. Such a lack of tape feed can have various causes: it can be the result of exhausting the contents of the can or a sliver break between the can 6 and the corresponding pair of rollers 4/5. However, it can also happen, for example, that the sliver ₂ breaks on the table 1, ie between the pair of rollers 4/5 and the working elements (not shown), making it impossible to transport the sliver ₂ on the table 1. The inventive parking device should in all these cases with certainty, and above all quickly all _T ex tilmaschine off, definitely so that the outgoing sliver end remains on the table 1 and can be connected there with the beginning of a sliver of hand.

The electrical storage device essentially consists, according to the invention, of a rocker 7 assigned to each sliver 2 and tiltable between a working position and a storage position, which, as shown in FIGS. 1 and 2, on the side edge 3 of the table 1, in the immediate vicinity of the pair of rollers 4 / 5, is tiltably supported about a tilt axis 8.

3a to 3c show the constructional details and the mode of operation of the parking device according to the invention in an enlarged schematic representation. The corresponding elements in FIGS. 1 and 2 are also designated with the same reference numbers here.

3a shows the parking device according to the invention while the machine is running correctly. The rocker 7 is shown here in its working position A, in which, according to the invention, it is located under the normal running sliver 2, without touching it and tiltable about the tilt axis 8. According to the invention, the rocker 7 has such a mass distribution that it moves clockwise in the working position A shown here (in this illustration, in which the sliver 2 moves on the table 1 from right to left according to arrow n) Directed torque m is about the tilt axis 8 and thus is held against a stationary stop 9. The rocker 7 can be tilted counterclockwise only by overcoming the self-holding force caused by the torque m and by passing a dead position in which the torque m becomes zero.

10 denotes a contact point which is electrically insulated from the infeed table 1 in a manner known per se (cf. the examples in FIGS. 4 to 6). The contact of this contact point 10 to the rocker 7 includes a likewise any person skilled in the known electrical _N iederstromüberwachungsschaltkreis, whereby the drive motor (not shown) of the machine is stopped immediately. The contact point 10 together with the rocker 7 forms a shut-off contact for the machine. The rocker 7 can be tilted from the working position A to the storage position B for two basic reasons, corresponding to two basic errors in the working conditions of the machine. These two cases are shown schematically in FIGS. 3b and 3c.

3b shows what happens when the material runs out of the can 6, that is to say the can 6 is empty, or when the delivery of the sliver 2 from the can 6 is interrupted. In this case, the pair of rollers 4/5 no longer feeds belt 2, so that a free belt end 11 must run over the rocker 7. The free end of the tape 11 has to, because the sliver 2 is no longer clamped between roller 04.05 and thus no longer as strength during the correct operation of _F. 3a, over which the rocker 7 can run tautly while maintaining a distance, fall on the rocker 7 and pass through it in a sweeping manner. According to the invention, the moment m now only has to be so great that the influence of the outfeed band end 11 on the rocker 7, acting in the opposite direction to m, causes the rocker 7 to quickly and reliably tip over in the counterclockwise direction. The influence of the belt end is based on two forces, namely the weight of the belt itself and the friction generated by its sliding movement from right to left on the rocker surface 12. The total of these two forces must be able to overcome the moment m, with which the rocker 7 immediately tips over and comes to a stop on the contact point 10 and thus falls into the storage position B. The machine is shut down immediately.

So that the response time of the rocker is reduced, it is advantageous if its mass is kept small. This can include by using light materials such as Light metal, or by other design measures (e.g. recesses), as will be shown in more detail with the help of further exemplary embodiments.

In Fig. 3c the operation of the _A b-adjusting device according to the invention in the case of the second basic error is shown, namely when the sliver on the infeed table 1, ie after the pair of rollers 4/5 breaks for some reason, for example due to excessive tension. In this case, the pair of rollers 4/5 continues to convey sliver, but this is no longer is removed and thus accumulates on the rocker 7 as a pile of fibers 13. Experience has now shown that when the rocker 7 is placed in the immediate vicinity of the pair of rollers 4/5, as shown in FIGS. 3a to c, and due to the high working speeds common today, the sliver 2 from the clamping point of the Roller pair 4/5 is "shot out" with a relatively high inertia, so that it preferably sits on the left side of the rocker 7, which immediately causes it to tip over into the storage position B. The dimensioning of the rocker 7 is therefore advantageously chosen taking into account the working speed of the machine so that the process described can be done without wasting time, which is very easy to determine experimentally.

4 shows a favorable form of a rocker 7 in a larger perspective view. The rocker 7 consists of two legs 14 and 15, which are connected in the middle by a hub 16. The hub 16 has a bore in which the tilt axis 17 can be accommodated with a sliding seat. The tilt axis 17 is attached to a vertical edge 18 of the inlet table 1. The edge 18 is opposite the horizontal surface 19 of the inlet table 1 by means of e.g. an insulation layer 20 electrically insulated.

According to the invention, the weight of the leg 15 is higher than that of the leg 14, so that the moment m can also act on the rocker 7 in a clockwise direction.

The left leg 14 of the rocker 7 has two features which are very favorable in terms of the reaction speed and the reliability of the parking device.

The recesses 21 in the base of the leg 14 serve the first-mentioned purpose: the mass of the rocker 7 thus becomes smaller and its inertia is reduced accordingly. To improve reliability, the comb-shaped teeth 22 of the free, left end of the leg 14 serve, which is additionally angled upward with the lower part of the leg 14. Thanks to this shape of the rocker, an outgoing sliver of fiber remains "hooked" in the rocker 7, or in its teeth 22, with which the rocker 7 is "carried along" to tip over.

In Fig. 4 it is further visible how the electrical contact between the rocker 7 and the inlet table 1 electrically insulated against the tilt axis 17 takes place. For this purpose, the surface 19 of the table 1 has an extension 23, against which the right leg 15 of the rocker 7 comes to a stop in the storage position B shown in dashed lines and thus establishes the electrical contact.

5 and 6 show a further variant of the parking device according to the invention, in which emphasis is placed on a maximum reaction speed of the parking.

The double-leg rocker 7, which largely corresponds in its construction to the rocker in FIG. 4, differs from this in that it has a movable, relatively heavy mass, the movement of which relative to the rocker accelerates the tilting of the rocker from the working position causes the storage. For this purpose, a thickening 25 is attached between the tilt axis 24 and the two legs 14 and 15, in which a plurality, for example three, in the case in question, chambers 26, in the form of, for example, bores, are let in. In these holes steel balls 27 are contained, which move freely along the entire hole can. Each chamber 26 is equipped with a closure cover 28. The location of the chambers 26 is opposite the rocker 7 now so that its axis hl in the working position A (in Fig. 5 in solid lines) of the rocker is slightly inclined to the right, while strength in the parking site B (in _F. 5 shown with dashed lines), the axis h of the chambers 26 is inclined to the left, namely at a larger angle with respect to the horizontal. During the movement of the rocker from the working position A into the storage position _B , the axis h of the chambers 26 thus passes the horizontal position in which the ball 27 contained in the chamber 26 is in an unstable state.

This device now works as follows: if, for any reason, the rocker 7 is caused to tip over from the working position A to the storage position B, it first moves counterclockwise until the axes h of the chambers 26 come into the horizontal position. The steel balls 27, which up to this point have stood against the right stop of the chambers 26, thus come into the unstable position and shift, also for reasons of inertia, from right to left in the corresponding chambers 26 The rocker 7 accelerates the tilting movement in the counterclockwise direction, so that the rocker 7 reaches the storage position B faster, in which an extension 29 comes to a stop against the edge 30 of the inlet table 1, which is electrically insulated from the tilt axis 24, and switches off the machine.

The ball 27 is of course representative of a body made of a relatively heavy material and movable perpendicular to the tilt axis 24 of the rocker 7, the function of which is to increase the tilting moment k acting on the rocker 7 in a counterclockwise direction. Another The advantage of this solution, in addition to the above-mentioned shortening of the reaction time, is that the contact pressure, ie the pressure on the contact point between the edge 30 and the extension 29, is increased, which improves the reliability of the parking device.

Is due to the fact that the herein described electric _A bstellvorrichtung not in the working position A by the material contacts that mentioned in the introduction disadvantages do not apply the prior art, namely the risk of contamination of the apparatus and the damage of the running sliver in its application. This improves the reliability of the shelf, which eberwachungsvorrichtungen as with all _U, which rarely but must function safely, can be provided by pollution in question, and the quality of the slivers generated since the formation of dangerous "Faserschnäuzen" which periodically by Sliver and can cause a gross error in the finished product is avoided. Furthermore, the electrical parking device claimed here is characterized by a very short reaction time, particularly in the last-described variant, which makes the subsequent attachment operation of the missing tape easier.

Claims (7)

1.Electric parking device for a textile machine fed with fiber tapes, in particular a draw frame, with a rocker that can be tilted per incoming fiber tape between a working position and a storage position, the tilting of which is caused by the running out of the fiber tape and causes the actuation of an electrical shutoff contact, characterized in that is arranged tiltably, and that the mass distribution in the rocker (7) is selected as the rocker (7) of the same under the normal running sliver (2) without contact and around a horizontal and _F aserbandrichtung perpendicular tilt axis (24 8;; 17) that this is in the working position (A) against a stop (9) and its tilting into the storage position (B) is achieved by overcoming the self-holding force by means of an external force, while passing a dead position. 2. Electrical parking device according to claim 1, characterized in that on the rocker (7) at least one body made of a relatively heavy material is movable vertically to the tilt axis (24) so that when passing through the dead position the body is relative to Rocker (7) moves and causes an increase in the tilting moment (k) acting on the rocker (7). 3. Electrical storage device according to claim 2, characterized in that the body is a steel ball (27) movable in an elongated chamber (26). 4. Electrical parking device according to claim 2, characterized in that the part of the rocker (7) directed in the running direction of the sliver (2) is formed with comb-shaped teeth (22). 5. Electrical parking device according to claim 1, characterized in that the rocker (7) is low in mass. 6. Electrical parking device according to claim 1, characterized in that the rocker (7) consists of light metal. 7. Electrical storage device according to claim 1, characterized in that the tilt axis (17; 24) of the rocker (7) on an inlet table (l) with electrical insulation (20) is attached to it and the shutdown contact is accomplished in that in the storage position (B) the rocker (7) on the table (1) comes to a stop.

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