EP0353575B1 - Stopping device for a silver - Google Patents

Description

The invention relates to a match stop device on a drafting system of a spinning machine e.g. a ring spinning machine or jet spinning machine.

When spinning without disintegrating into individual fibers, the fiber material to be spun in the individual spinning position is normally delivered to this spinning position via a drafting system, the drafting system comprising a plurality of pairs of rollers. The fiber material template can be in the form of an untwisted band, for example a stretch band, or in the form of a slightly twisted roving (for example from the flyer). In this description, the term "fuse" indicates an elongated structure of fiber material, which serves as a template for a spinning machine, regardless of whether this template is provided with a support twist or not.

When a thread break occurs in a single spinning position, the fiber feed at this spinning position is advantageously interrupted before the last pair of rollers of the drafting system (called output, export or delivery roller pair) in order to reduce the loss of material and the risk of winding around a delivery roller. For this purpose, it is already known (DE-A-3318925) to pivot a clamping element with a clamping edge tangentially into the converging space on the input side of the pair of input rollers when the thread breaks, so that the fuse is clamped between the clamping element and one input roller. The self-threading of the fuse into the drafting system is then no longer guaranteed due to the tangential pivoting movement of the clamping element when re-spinning, and there is friction between the clamping element and the drafting system rollers as long as the thread break has not yet been remedied.

It is also known (DE-A-2952533) to lift the upper (pressure) roller from the lower (driven) continuous cylinder when the thread breaks, by means of a lifting element designed as a curved path acting on the axis of the upper roller, and to lift the fuse against the raised one (stationary) roller to clamp by a clamping element on the output side of the roller. The fuse thus remains threaded with the pair of input rollers even though the fiber feed to the spinning position has been interrupted. When re-spinning, the raised printing roller must be brought back into contact with the delivery cylinder and the clamping effect must be released. The Arrangement is complex and the coordination of the various functions (lifting / match clamps) is not easy.

GB-A-1 438 276 (Fig. 3/4) shows a match stop device with a thread break sensor which triggers a movement of a piston. The piston pushes a finger against the input pressure roller of a drafting system, clamps the fuse against this roller and lifts the pressure roller from the input bottom roller. The piston is moved approximately radially to the pressure roller that can be lifted off. A corresponding arrangement is defined in the preamble of claim 1.

Despite these and other proposals for realizing a match stop, and despite the obvious advantages that would result from the use of such a match stop, no solution has so far been able to prevail.

The arrangement according to GB-A-1 438 276 in particular is complex because it requires an additional element which is necessary for clamping or lifting the printing roller. This element or its movements complicate the problem of the limited space in the inlet of a drafting system and / or require a long path of movement for the clamping element between its waiting and operative position.

Accordingly, it is the object of this invention to propose an arrangement which is relatively simple and space-saving compared to GB-A-1 438 276.

The solution to this problem is listed in the characterizing part of claim 1.

The invention accordingly provides a drafting system with an input roller pair available for each spinning position, the one roller of the pair being operated by a drive is set in rotation about its own longitudinal axis and the revolutions of this first roller are transmitted to the second (pressure) roller by contact between the rollers of the pair. The second roller is only assigned to the relevant spinning position, while the first roller can also be present as a single roller per spinning position or in the form of a continuous cylinder extending over several spinning positions.

The fiber guide element can e.g. a funnel or a sliver condenser, guides the fiber stream in normal operation and is pressed against the pressure roller of the pair of input rollers when the thread breaks, thereby removing the contact between the rollers and almost simultaneously holding the fuse against the outer surface of the pressure roller. Such a fiber guide element is preferably arranged on the input side of the pair of input rollers.

In a preferred variant, the fiber guide element executes a rotary movement between the waiting position and the operative position.

The sliver clamping point, i.e. the point at which the sliver is clamped between the fiber guide element and the pressure roller after the contact between the drafting rollers has been removed, is normally offset slightly around the circumference of the pressure roller in relation to the normal clamping line of the input roller pair. The pressure roller is moved to remove contact with the input roller on a path which is an essentially straight extension of a pressure roller radius running through the nip.

The fiber guiding element can be assigned to the relevant spinning position via a signal transmission system Thread monitors are connected so that in normal operation the switching of the fiber guide element is triggered by the thread monitor detecting a broken thread in the spinning position. In addition, an actuatable means can be provided to switch off the effect of the thread monitor when the machine starts up if there is no thread in the spinning position at this time.

Fig. 1

im Querschnitt das Eingangswalzenpaar eines Streckwerkes gemäss dem Stand der Technik mit verschiedenen Möglichkeiten die auch in Zusammenhang mit der vorliegenden Erfindung verwendet werden können,

Fig. 2

eine erste Ausführung nach dieser Erfindung,

Fig. 3

eine praktische Ausführung eines Systems gemäss der Anordnung der Fig. 2,

Fig. 4

die Anordnung von Fig. 3 mit einem geänderten Zustand des Signalsystems,

Fig. 5

die Anordnung der Figuren 3 und 4 nach Aufhebung der Berühung zwischen den Eingangswalzen des Streckwerkes,

Fig. 6

ein Schema zur Erklärung des Signalsystems für eine Ausführung gemäss den Figuren 3 bis 5.

Two examples of this invention will now be explained in more detail as examples using the schematic representations in the figures of the drawings. It shows:

Fig. 1

in cross section the pair of input rollers of a drafting system according to the prior art with various possibilities which can also be used in connection with the present invention,

Fig. 2

a first embodiment according to this invention,

Fig. 3

a practical embodiment of a system according to the arrangement of FIG. 2,

Fig. 4

the arrangement of Fig. 3 with a changed state of the signal system,

Fig. 5

the arrangement of Figures 3 and 4 after lifting the contact between the input rollers of the drafting system,

Fig. 6

a diagram for explaining the signal system for an embodiment according to Figures 3 to 5.

In Fig. 1, the input cylinder EZ and the pressure roller DW form the input roller pair of a drafting system, not shown, on a spinning machine, not shown, for example. a ring spinning machine or a nozzle spinning machine. The input cylinder EZ extends over several spinning positions (possibly over an entire machine side, i.e. is in the form of a so-called continuous cylinder). The pressure roller DW, however, is assigned to a single spinning position (not shown). In normal operation, the pressure roller DW is pressed against the input cylinder EZ in order to keep the jacket surfaces of the roller DW and the cylinder EZ in contact with one another along the clamping line KL. The clamping line KL preferably runs parallel to the longitudinal axis LAD of the printing roller DW and the longitudinal axis LAZ of the input cylinder EZ.

A suitable drive (not shown) causes the cylinder EZ (according to FIG. 1) to rotate clockwise about its own longitudinal axis LAZ. The contact between the printing roller DW and the input cylinder EZ transfers the revolutions of the cylinder to the printing roller, so that the latter (according to FIG. 1) is rotated counterclockwise around its own longitudinal axis LAD. A fuse, not particularly indicated) can be introduced into the converging space on the input side of the pair of feed rollers up to the clamping line KL and is drawn into the drafting system in the driven feed cylinder EZ in order to generate a fiber flow FS through the drafting system. Since the other drafting elements have no significance for this invention, they have been omitted from the basic diagram of FIG. 1 (and FIG. 2) in order to be able to concentrate on the essential elements.

As long as the working elements of the spinning position, not shown, work normally to process the fiber material supplied by the drafting system into a yarn, the pressure roller DW remains in the position shown in order to pull the material to be spun from the template, not shown, into the drafting system. However, if there is a thread break in this spinning position for any reason, the fiber feed should be interrupted as close as possible to the pair of feed rollers.

In the prior art, a clamping element KE1 is moved in the direction of arrow P from a waiting position against the printing roller DW in order to form a clamping point KS by contact with the outer surface of the printing roller DW. The waiting position of the element KE1 is on the opposite side of the fiber stream FS from the pressure roller DW. By moving the element KE1 transversely to the fiber stream FS to the clamping point KS1, the fiber stream is initially deflected slightly and then pinched off by the contact between the element KE1 and the pressure roller DW. By moving on of the element KE1 in the same direction, the pressure roller DW is slightly lifted off the input cylinder EZ. Since the printing roller is no longer driven by the input cylinder EZ and at the same time is braked by the clamping element KE1, the printing roller stops immediately.

In the course of the movement between the normal operating position (FIG. 1) and the raised position of the pressure roller DW, the longitudinal axis LAD of this roller follows a path AB1 (dashed line) which represents an extension of the pressure roller radius R running through the nip point KS1. The support arrangement (not shown) for the pressure roller DW must be designed accordingly to enable this movement.

Since the downstream drafting roller pairs, which are not shown, remain unaffected, the fiber stream FS continues to flow downstream from the nip point KS1. The fibers thus supplied by the drafting system must be picked up and taken away by a suitable suction device (not shown). The fibers held at the clamping point KS1 remain ready for re-spinning. When the thread break has been remedied, the clamping element KE1 can be moved back into the waiting position, the pressure roller DW being brought back into its operating position, ie in contact with the feed cylinder EZ, by the support arrangement. As soon as the clamping line KL is formed again, the fibers at the clamping point KS1 are released by the clamping element KE1, these fibers either lying in the newly formed clamping line KL or in the converging space on the input side of the pair of insertion rollers. In the latter case, these fibers are immediately removed from the input cylinder EZ feeds into the clamping line KL so the fuse that has now been released is drawn back into the drafting system. The system is therefore self-threading.

The nip KS1 is, as already mentioned, according to the prior art, on the input side of the insertion roller pair, but this is not essential for the present invention. A clamping element KE2 could be arranged on the output side of the pair of feed rollers in order to form a corresponding clamping point KS2 in the diverging space of this pair of rollers. In this case, the longitudinal axis LAD of the printing roller DW would preferably be moved along the path AB2 between the operating position and the raised position in order to remove the contact between the printing roller and the input cylinder EZ. For space reasons, however, the alternative solution on the input side of the pair of input rollers will normally be preferred.

Fig. 2 shows a first embodiment of the inventive principle. In this case, the pressure roller DW works together with a driven feed roller EW which is individually assigned to the corresponding spinning position (ie does not extend over several spinning positions), the use of the invention in combination with a cylinder EZ according to FIG. 1 also being possible . The fiber stream FS is guided from the template (not shown) via a guide element FE into the clamping line KL of the pair of feed rollers. The guide element FE is pivotally mounted about a pivot point DP and can be pivoted about the pivot point DP from a guide position (shown in FIG. 2) into an intermediate position (not shown) by a suitable means (not shown). In the latter position, an edge L at the front end of the guide element is in contact with the Print roller DW to form the nip KS. Due to the further movement of the element FE, the pressure roller DW is then lifted off the roller EW, the longitudinal axis LAD of the pressure roller being able to follow either a straight path ABG or a curved path ABK.

As in the case of the arrangement of FIG. 1, the clamping point KS is slightly offset in relation to the clamping line KL in the circumferential direction of the pressure roller DW, so that the fibers clamped at the point KS either lie in the clamping line KL during the return movement of the pressure roller DW or through the Input roller EW can be quickly fed back into the clamping line KL. In order to simplify the construction, the longitudinal axis LAD of the printing roller is no longer arranged (as in FIG. 1) perpendicularly above the longitudinal axis LAZ of the input roller EW, but is offset in the direction of the fiber flow in order to give the printing roller a slight "overhang" with respect to the input roller To give EW. Such an arrangement is also shown in FIGS. 3 to 5.

Figure 3 shows the feed roller pair EP, the middle roller pair MP and the delivery roller pair LP of a two-zone drafting system. The fiber material supplied by the drafting device is delivered to a spinning position SP, which is only indicated schematically, and there to a yarn G (FIG. 4) by working elements of the spinning position (not shown) (for example by the spindle-ring traveler combination of a ring spinning machine or the suitable nozzle arrangement of a nozzle spinning machine) processed. The fiber material to be spun is fed into the pair of input rollers during operation EP passed through the guide channel 10 of a condenser K. As already mentioned, this material is drawn into the drafting system from a template (not shown) (eg a spool or a can) through the pair of input rollers EP.

According to the principle outlined in FIG. 2, the condenser K is rotatably mounted on a pin 12. In addition, the condenser K is equipped with a cantilever 14 which, at its end remote from the pin 12, cooperates with an actuating device BV described below.

The device BV comprises a chamber 18 carried by the arm 14 and containing a piston 16. The piston 16 is connected via a piston rod 20 to a stationary part 22 of the machine frame (not shown in more detail). A compressed air line 24 opens into the end of the chamber 18 remote from the part 22. When air is supplied with a suitable pressure via the line 24 into the chamber 18, the arm (lever arm) 14 is pivoted counterclockwise around the pin 12 according to FIG. 3 to bring the output of the condenser K into contact with the pressure roller DW of the input roller pair EP. The compressed air works against a prestress exerted by a compression spring 26. The spring 26 is located between the chamber 18 and another stationary part 22A of the frame. In the absence of the compressed air supply, however, the lever arm 14 and the condenser K are held in a normal or operating position (FIGS. 3 and 4) by the compression spring 26. In this operating position, the condenser K (or its channel 10) opens into the converging space on the input side of the pair of feed rollers EP without the pressure roller DW touch so that the fiber stream FS (Fig. 4) can flow freely through the drafting system.

In the normal or operating position of the condenser K, the piston 16 lies at the end of the chamber 18 remote from the part 22 (FIGS. 3 and 4). At the end of the pivoting movement of the condenser K caused by the compressed air, the piston 16 lies at the end of the chamber 18 facing the part 22 (FIG. 5). The connection (not shown) between the piston rod 20 and the part 22 must be designed in such a way that it enables the necessary pivoting movement of the boom 14. In the course of this movement from the operating position (FIG. 4) into the operative position (FIG. 5), the aforementioned edge L (see also FIG. 2) forms a nip KS with the pressure roller DW, the formation of this nip KS in front of the Completion of the mentioned pivoting movement takes place. The pressure roller DW is lifted off the input roller EW by the further pivoting movement of the condenser after the nip KS has been formed. The contact between the pressure roller DW and the input roller EW forming the clamping line KL (FIG. 3) is thus eliminated. In operation, as long as the fiber material FS is processed from the spinning position SP into a yarn G, the chamber 18 remains without compressed air. The production of a yarn G in the spinning position SP is constantly monitored by a thread monitor FW. If the yarn production is interrupted in this spinning position, the thread monitor FW triggers the supply of compressed air from a suitable source Q via the line 24 into the chamber 18 via a signal line 28 and via a compressed air valve M, which triggers the pivoting movement of the condenser K. .

After a thread break occurs, the drafting system temporarily delivers fiber material. This material is carried away by a suction AS arranged on the delivery roller pair LP. After the formation of the clamping point KS and the lifting of the pressure roller DW, the new introduction of fiber material from the template into the drafting system is interrupted. The material already present in the drafting system is passed on from the pair of center rollers MP and the pair of delivery rollers LP to the suction system AS. The fibers held at the clamping point KS (FIG. 5) cannot participate in this fiber stream FS, so that the fiber stream is interrupted in the pre-drafting zone between the input roller pair EP and the middle roller pair MP. The fibers F remain "threaded" with the pair of input rollers EP.

When the thread break is eliminated, the valve M is readjusted in order to interrupt the compressed air supply from the source Q to the line 24 and to vent the chamber 18 via the line 24 and a line 32. This enables the return of the lever arm 14 and the condenser K to the operating position (FIGS. 3 and 4) under the biasing force exerted by the compression spring 26. As a result, the clamping line KL is formed again by restoring the contact between the pressure roller DW and the input roller EW and almost simultaneously the previously held fibers F are released again by the removal of the clamping point KS, which causes the new introduction of fiber material from the template into the drafting system to restore the fiber stream FS. The arrangement is accordingly self-threading.

The vacuum at the suction AS can be simultaneously be interrupted with the new entry of the fiber feed so that the newly delivered fibers are now delivered to the provided spinning position SP. The suction AS can be connected again to a vacuum source, not shown, if the thread monitor FW detects a new thread break.

The previously mentioned signal line 28 comprises a switch 34 which can be actuated by a push button D, a switch 36 which can be actuated by the thread monitor FW and a coil 38 which sets the valve M. The functions of various cooperating elements in the figures are now illustrated on the basis of the signal diagram shown in FIG 3 to 5 are explained in more detail.

By actuating a main switch, not shown, the whole machine is put into operation. As a result, according to FIG. 6, current is applied to signal line 28 at time T1.

• der Schalter 34 geschlossen, da der Druckknopf D noch nicht betätig worden ist, und
• der Schalter 36 geschlossen, da kein Garn im Fadenwächter FW vorhanden ist.

Is at that time

• the switch 34 is closed because the push button D has not yet been pressed, and
• the switch 36 is closed because there is no yarn in the thread monitor FW.

The coil 38 therefore actuates the solenoid valve M so that compressed air from the source Q is conducted into the chamber 18. Accordingly, the condenser K is immediately moved from the operating position (FIG. 3) to the operative position (FIG. 5) in order to lift the pressure roller DW from the insertion roller EW and to clamp the fibers F which are still threaded with these rollers.

The state of the main switch is shown on the top row of the signal diagram in FIG. 6, the state of the push button D on the second top row, the state of the thread monitor FW on the third top row and the state of the chamber 18 on the bottom row.

When the spinning position SP is ready for spinning, the push button D is actuated (FIG. 3), so that the coil 38 associated with the solenoid valve M is de-energized. The compressed air supply to the chamber 18 is accordingly interrupted, which causes the condenser K to return to the operating position. However, since no yarn runs through the thread monitor FW, the switch 36 remains closed (in FIG. 6, time T2).

After the spinning position SP has started again to process the newly supplied fiber material into a yarn G, the thread monitor FW determines the presence of this yarn G and opens the switch 36 (in FIG. 6, time T3). Shortly afterwards (at point T4) the push button D can be released again (e.g. by a suitable time relay, not shown) in order to close the switch 34 (FIG. 4). The overall arrangement has now reached the normal operating state and is ready to react to a possible thread break (in FIG. 6, time T5) with the opening of the switch 36 by the thread monitor FW.

After the spinning position SP has been made ready to start again by the operator (manually or automatically), the starting process can be triggered again by actuating the push button D (in FIG. 6, time T6). Because the process when starting (after a thread break) corresponds exactly to the process of re-spinning (after the machine has been stopped), this process for re-spinning will not be repeated.

The invention is not restricted to details of the illustrated embodiment. It is not necessary that the movement of the clamping element from its waiting position (in the preferred variant from the operating position of the condenser) into the operative position (clamping the fuse) is carried out by a pivoting movement. The same effect could be achieved by a linear movement of the clamping element. However, the preferred variant is particularly advantageous over the arrangement described in DE-A-2952533, in which the number of working elements and the work paths are kept small, which enables a space-saving and simple arrangement. In addition, this invention achieves the advantage that the formation of the nip and the removal of contact between the insertion rollers occurs approximately simultaneously. This ensures that the separation of the fiber stream takes place after the formation (downstream of the) clamping point. However, since the clamping point KS is formed just in the vicinity of the clamping line KL, the retained fibers remain ready for the beginning of the sliver insertion.

The pressure roller DW can be formed as a double roller unit, the rollers of one unit being assigned to respective adjacent spinning positions. There this arrangement for ring spinning is well known, it will not be explained here.

In contrast to an arrangement according to DE-A-2 952 533, according to this invention the clamping forces exerted on the outer surface of the pressure roller are also used to lift the pressure roller and thereby to remove contact between the rollers of the pair of input rollers.

With the preferred variant shown in FIGS. 3-5, a particularly space-saving and simple design is made possible by utilizing the condenser or the guide element as the clamping element. For this purpose, a condenser enclosing the fuse opens against the pressure roller in order to simplify the formation of a clamping edge on the condenser. By using the fiber guide as a clamping element, the latter can be in its "waiting" (fiber-guiding) position particularly close to the pressure roller, and thus to the nip.

Claims (6)

1. A slubbing stop apparatus in a drafting arrangement of a spinning machine with a first drivable roller (EW) and a second roller (DW) which is drivable by coming into contact with the first roller and with a means (FE, L; K, L) which is movable at least approximately radially to the second roller (DW) between a waiting position (Fig. 2; Figs. 3 and 4) and an operative position (Fig. 5) in order to form a nip position (KS) for the slubbing by coming into contact with the surface area of the second roller (DW) and to lift the second roller (DW) from the first roller (EW), characterized in that the means comprises a fibre guide element (FE; K) which in the waiting position guides the slubbing into or from the nip line (KL) of the two rollers (EW, DW) and is provided with at least one edge (L) which in the movement to the operative position is movable in such a way that the nip position (KS) is formed between said edge (L) and the second roller (DW).
2. An apparatus as claimed in claim 1, characterized in that the fibre guide element (FE; K) is held rotatably.
3. An apparatus as claimed in claim 1 or 2, characterized in that the fibre guide element (K) is a slubbing condenser with a tapered guide duct (10).
4. An apparatus as claimed in one of the claims 1 to 3, characterized in that the first and second roller (DW, EW) jointly form the pair of input rollers of the drafting arrangment.
5. An apparatus as claimed in one of the previous claims, characterized in that the guide element (FE; K) is arranged on the input side of the pair of rollers (DW, EW).
6. An apparatus as claimed in one of the previous claims in combination with a spinning position (SP) and a stop motion (FW) for monitoring the yarn supplied by the spinning position, characterized in that the movement of the guide element (FE; K) is initiated by a signal issued by the stop motion (FW).

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