Title of Invention

A DRAWFRAME AND A SLIVER BUILD-UP SENSOR FOR A TEXTILE MACHINE

Abstract

What is presented is a drawframe for the drawing of at least one fibre sliver FB, with a drawing mechanism, with a sliver funnel (33) following the drawing mechanism and with a pair of calender rollers (13, 14) which is located further downstream and which draws off the f ibre s1iver (FB') drawn in the drawing mechani sm through the sliver funnel (33), transports it into a sliver duct arranged downstream of the pair of calender rollers and finally deposits it into a spinning can, and also with a sensor (40) which, in the event of a sliver build-up at the inlet of the sliver duct, generates a signal for switching off the sliver transport. According to the invention, the sliver build-up sensor is arranged in the region of the sliver-funnel outlet. The invention likewise relates tu a sliver build-up sensor with a deflection element which is of essentially bar-shaped or sheet-like design and which can be oriented essentially in the fibre-sliver transport direction, (Fig. 3)

Full Text

Drawframe and sliver build-up sensor The invention relates to a drawframe for the drawing of at least one fibre sliver, with a drawing mechanism, with a sliver funnel following the drawing mechanism and with a pair of calender rollers which is located further downstream and which draws off the fibre sliver (FB) drawn in the drawing mechanism through the sliver funnel, transports it into a sliver duct arranged downstream of the pair of calender rollers and finally deposits it into a spinning can, and also with a sensor which, in the event of a sliver build-up at the inlet of the sliver duct, generates a signal for switching off the sliver transport. The invention relates, furthermore, to a sliver build-up sensor for a textile machine, with a deflection element deflectable out of its rest position into an alarm position in the event of a sliver build-up, an electrical signal for shutting down the drawframe being capable of being generated in the alarm position. Drawframes of this type with a sliver build-up sensor at the exit of the drawing mechanism are known. The fibre sliver leaving the drawing mechanism at a high speed of up to 1000 m/min must with a high degree of accuracy be transported through the sliver funnel and introduced by means of the calender rollers into the sliver duct which is arranged, as a rule, in a turntable rotating at high speed. Due to the most diverse possible causes, however, sliver build-ups often occur at the inlet of the sliver duct and must be detected immediately in order to prevent a continuous further conveyance of the drawn fibre sliver. The sliver build-up sensors used for this purpose are arranged in the immediate vicinity of the sliver-duct inlet. For example, a mechanical sensor in yoke form. which is arranged slightly below the sliver-duct inlet so as to run around the latter, is known. When fibre sliver builds up at the sliver-duct inlet, the yoke is pressed downwards and an electrical contact is closed. The signal generated thereby shuts down the machine and the sliver build-up can be eliminated manually. In another known drawframe, an only slightly bent wire yoke runs past the sliver-duct inlet perpendicularly to the fibre-sliver transport direction and terminates just in front of an inductive sensor element. When the wire is deflected by built-up fibre sliver, the wire end is moved away from the inductive sensor element, the latter thereupon transmitting a corresponding shutdown signal to the machine. The known versions have the disadvantage that the respective deflection element (round yoke, bent yoke) is deflected only when a relatively large amount of sliver material has already been conveyed by the calender rollers. The sliver transport or the machine is therefore shut down relatively late, as a result of which, on the one hand, a large amount of rejected drafted fibre material occurs and, on the other hand, the bulky sliver material can be removed only in a relatively complicated way. Also, the positioning of the known round yoke in relation to the existing suetion-air stream is not optimal, Since it is arranged in the dead corner, clogging with fly may occur more easily, this having an adverse influence on the switching behaviour. The object of the present invention is to develop a drawframe of the type mentioned in the introduction, in such a way that a rapid recording of a sliver build-up in the region of the sliver-duct inlet becomes possible, In the drawframe of the type mentioned in the introduction, this object is achieved in that the sensor is arranged in the region of the sliver-funnel outlet. In a sensor of the type mentioned in the introduction, the object is achieved in that the deflection element is of essentially bar-shaped or sheet-like design and can be oriented essentially in the fibre-sliver transport direction. The advantages of the invention are to be seen, in particular, in that a sliver build-up sensor is arranged in the region of emergence of the sliver from the sliver funnel. The sliver build-up sensor according to the invention is therefore arranged above the calender bearing or the calender rollers. This placement of the sliver build-up sensor in space has the result that even small quantities of fibre sliver which are not introduced directly into the sliver duct can be detected more immediately. In particular, the sensor is independent of the geometry and, in particular, of the diameter of the sliver duct and can consequently, for example, have a substantially smaller dimensioning. In a particularly preferred embodiment of the invention, the sensor is arranged on a carrier plate for sliver guide elements. In particular, such a carrier plate is designed as a holding device for the sliver funnel or as a holding device for a sliver-funnel carrier. The carrier plate may either be permanently installed or be designed, for example, so as to be pivotable, in order to allow better access, for example, to the pair of calender rollers when work is carried out on the drawing mechanism. The non-woven nozzle with non-woven nozzle insert or attachment may be arranged above the carrier plate. It is particularly advantageous if the sensor is arranaed on the underside of the said carrier plate and next to the sliver-funnel outlet. The sensor responds when the fibre sliver is deflected out of its transport direction and passes into the detection range of the sensor. It is beneficial for the stable mounting of the sensor if the latter is fastened in a recess on the carrier-plate underside. In a particularly preferred embodiment of the invention, the sensor is designed as an optical sensor. In the case of such optical sliver build-up monitoring, in contrast to the prior art, there are no moved and consequently contaminating sensor components in the region of the turntable. In particular, the very short reaction time of the optical sensor is advantageous. Furthermore, there is no need for any setting of mechanical parts'. In the event of a sliver build-up, the optical sensor triggers an electrical signal when the fibre sliver enters the sensing cone of the sensor. The electrical signal then leads .^to,. the shutdown of the machine. Particularly preferably, the optical sensor has a housing, in which both the transmission and the reception unit are accommodated. This form of construction is compact and therefore space-saving. Furthermore, it is easily possible to exchange the sensor if it is defective, without the transmission and the reception unit having to be coordinated with one another. Preferably, the sensing cone of the optical sensor is oriented essentially in the fibre-sliver transport direction. Moreover, if the optical sensor operates with background blanking-out, the reach of the sensor is limited, so that high operating accuracy owing to the exactly defined detection range is ensured. The sensor responds when, in the event of a sliver buildup, it receives reflections from the fibre sliver deflected out of the intended transport path. Particularly preferably, a pneumatic device is provided, the blowing stream of which is directed onto the sensor surface and/or onto the space in front of the sensor surface, Such a pneumatic device with at least one blowing nozzle serves for cleaning the optical sensor, so that no fibre fly can settle on the sensor surface or in order to remove such fibre fly again. When aligned with the space in front of the sensor surface, the pneumatic device prevents fibres from entering the region of the sensor surface. The invention likewise relates to a sliver build-up sensor designed as a mechanical sensor. This comprises a bar-shaped or sheet-like deflection element which, under corresponding sliver contact in the event of a sliver build-up, is deflected out of a normal or rest position into an alarm position. By the deflection element being deflected, one electrical contact is closed and another is opened, with the result that a shut-down signal for shutting down the machine is then triggered. The said bar-shaped or sheet-like deflection element is designed in such a way that, according to the invention, it can be oriented essentially in the fibre-sliver transport direction, that is to say parallel to the sliver-funnel axis. In the event of fault-free transport of the fibre sliver, therefore, the bar is located in an essentially vertical rest position, whereas, in the event of a sliver build-up, the fibre sliver runs up against the bar-shaped deflection element and deflects the latter, in order to generate a shut-down signal for shutting down the machine. As compared with a bar-shaped design of the deflection element, in some cases a sheet-like configuration may be advantageous, in order, if appropriate, to implement a larger detection range of the sensor. For example, such a sheet-like configuration in the form of a cylindrical part-surface around the sliver funnel is possible. It is beneficial for the operator's convenience if the deflection element itself is designed elastically, so that an operator has, for example, easier access to the sliver funnel and the calender rollers. The deflection element can then be pushed out of the operating path in a simple way with the back of the hand. In an alternative embodiment, the deflection element is designed rigidly. This embodiment may be selected, for example, when, because of the spatial situation, operating convenience is not restricted thereby. The mechanical sliver build-up sensor is in any event designed in such a way that it can be pivoted back into its initial position after the removal of the loading force caused by the fibre sliver touching it. In addition to the above-described elastic design of the deflection element, alternatively or additionally an elastic bearing may be provided, in which the - elastic, rigid or else plastic - deflection element is mounted- The bearing element is preferably designed non-conductively and is preferably fastened to the carrier plate. In this case, therefore, it is arranged between the carrier plate and the deflection element. Alternatively, the deflection element itself is mounted in the carrier plate. In this embodiment, the deflection element is designed elastically, preferably the end near the carrier plate having a lower elasticity than the end remote from the carrier plate. This design ensures simpler access to components lying behind it, such as the sliver funnel, the calender rollers, the sliver-duct inlet and the like, in that the deflection element can easily be pivoted out of the operating path. The deflection element and/or the bearing element are preferably designed as a spring, rubber buffer, elastomeric buffer or the like. To make and break the electrical contact for generating a shut-down signal, the deflection element is advantageously coupled to a metallic switching element which can also be deflected in the event of a sliver build-up. In the event of a corresponding deflection of the deflection element, this switching element preferably comes into contact with a metal contact on a carrier plate for sliver guide elements. Preferably, the carrier plate itself is of metallic design. When the deflection element springs back into its rest position, the contact is broken again, so that follow-up recordings of sliver build-ups are possible in turn. In a preferred embodiment, the switching element is of bell-shaped design and is advantageously arranged around the said bearing element. In this embodiment, it is appropriate if the deflection element sits on the switching element on the outside and, advantageously, the bearing element and the deflection element are coupled to one another through an orifice in the switching element. The mechanical sliver build-up sensor according to the invention is preferably arranged on the carrier plate for sliver guide elements and, in particular, the carrier plate for the sliver funnel. In the embodiment described above, in the case of a sliver build-up, the bell-shaped switching element, which is maintained, for example, at a positive potential, touches the metallic carrier plate to which, in this case, a negative potential is applied. The metallic contact closure then generates an electrical signal for shutting down the machine. The corresponding device for shutting down the machine is state of the art and does not need to be explained any further here. It is beneficial for improving the switching sensitivity if the switching-contact spacing in the mechanical sliver build-up monitoring is kept small. In the embodiment described above, this switching-contact spacing is preferably approximately 0.1 to 0.3 mm. The spacing is in this case the distance between the switching element and the carrier plate, as measured in the fibre-sliver transport direction through the sliver funnel, that is to say in the direction of extent of the elongate deflection element. Advantageous developments of the invention are characterized by the features of the subclaims. The invention is explained in more detail below with reference to the figures, of which: Figure 1 shows a diagrammatic side view of a known drawframe with a separate enlargement of a detail; Figure 2 shows a perspective top view of a carrier plate for a sliver funnel; Figure 3 shows the carrier plate of Figure 2 in a sectional side view along the line A-A according to Figure 4, with an optical sliver build-up sensor; Figure 4 shows the carrier plate according to Figures 2 and 3, as seen from below; Figure 5 shows a carrier plate for a sliver funnel, similar to Figure 2; Figure 6 shows a sectional side view of the carrier plate according to Figure 5 along the line B-B according to Figure 7, with a mechanical sliver build-up sensor, and Figure 7 shows the carrier plate according to Figures 5 and 6, as seen from below. The basic functioning of a drawframe is explained below with reference to Figure 1. According to this example from the prior art, a plurality of essentially non-twisted fibre slivers FB are presented next to one another to the drawframe. It is likewise possible to supply only one fibre sliver FB to the drawframe. Arranged at the entrance to the drawframe is a funnel 1 which condenses the fibre slivers FB. Other condensing devices may be used. After running through a sensing device 2, 3 consisting of a pair of tracer rollers, the in this case compressed fibre sliver FB' , which consists of the individual fibre slivers FB, is led into a drawing mechanism 4. The drawing mechanism 4 has, as a rule, three drafting members or pairs of rollers, between which the actual draft takes place. These pairs of rollers are the pair of feed rollers 5, the middle pair of rollers 6 and the pair of withdrawal or delivery rollers 7, which rotate at a circumferential speed increased in each case in this order. By means of this design, the fibre sliver FB' is drafted according to the ratio of the circumferential speeds. In the main drafting zone, which is formed by the middle pair of rollers 6 and the pair of delivery rollers 7, there is additionally arranged a pressure bar 8 for diverting the fibre sliver FB' and therefore for the better guidance of, in particular, the fibres not nipped between the two pairs of rollers (what are known as floating fibres). The drafted fibre sliver FB' is combined with the aid of an upper diverting roller 9 in a plurality of sliver guide elements (see the enlargement of a detail) and is introduced into a curved sliver duct 16 via a pair of calender rollers 13, 14, one of which is acted upon by force via a spring 15 for the purpose of sliver cross-section measurement. After passing through the sliver duct 16, which is arranged in a turntable 17 rotating at the angular speed o, the sliver FB' is deposited in a can 18 at a speed VL. To compensate the sliver-mass fluctuations, in the drawframe illustrated in Figure 1 the signals from the sensing device 2, 3 are used. The fibre sliver FB' is led between these two sensing discs 2, 3, the deflections of the movable-location sensing disc 3 pressed against the fixed-location sensing disc 2 being used as a measure of the sliver cross section of the fibre sliver FB' . For example, the sensing disc 3 is coupled to an inductive sensor element 2 0, the output signals of which are first transmitted in the form of electrical voltage signals into a store 21, which takes into account the path or time difference between passing the sensing device 2, 3 and entry into the drawing mechanism 4 (FIFO store = First-In-First-Out store) and then, after this time difference has elapsed, to an evaluation and regulating unit 22. In the present case, the compensation of the mass fluctuations in the main drafting zone is achieved by the variation in the rotational speed of a booster drive 23 which generates a control rotational speed for an epicyclic gear 24. The lower rollers of the pair of feed rollers 5 and of the middle pair of rollers 6 are driven at this controlled output rotational speed of the epicyclic gear 24, into which a main motor 25 drives. The speed of the lower roller, driven by the main motor 25, of the pair of delivery rollers 7 remains constant in the present case and ensures an exactly calculable production of fibre sliver FB'. The detail of Figure 1 illustrates, enlarged, the sliver guide elements between the drawing inechanism 4 and the calender rollers 13, 14. The embodiment, shown diagrammatically, corresponds to that of the known drawframe RSB D30 from the company Rieter. The central element is in this case a carrier plate 30. The carrier plate 30 has lateral bearing bolts 36 for the articulation of a non-woven guide nozzle 34 (see arrow 37) , so that the latter can be pivoted forwards above the carrier plate 30 in the event of a sliver build-up at the nozzle 34. The non-woven guide nozzle 34 shapes the non-woven or fibre sliver FB' coming from the drawing mechanism 4 into a firmer sliver FB' . Inserted into the non-woven guide nozzle 34 is a non-woven nozzle insert 35, through which the fibre sliver FB' is led. There follows, in the sliver transport direction, a carrier 32 which is held in the carrier plate and into which a sliver funnel 33 is inserted. Figures 2 to 4 illustrate in more detail the carrier plate 30, on the one hand with and on the other hand without a carrier 32 and sliver funnel 33. The carrier plate 30 has a conically tapering orifice 31, into which the carrier 32 can be inserted from above. As may be gathered particularly from Figure 3, the sliver funnel 33 tapers to a point in the fibre-sliver transport direction and projects into the gap formed by the calender rollers 13, 14. Only the calender roller 14 is illustrated in Figure 3 by broken lines. The fibre sliver FB' undergoes compression, and therefore acquires higher strength, when it enters the sliver funnel 33 and as a result of the calender discs 13, 14. This sliver strength is necessary in order to ensure a reliable draw-off and good depositing into the can 18 (see Figure 1). Not only can a sliver build-up occur at the non-woven guide nozzle 34, but a sliver build-up at the entrance of the sliver duct 16 often also cannot be prevented. In continuous production, large fibre-sliver quantities are in this case accumulated between the pair of calender rollers 13, 14 and the inlet of the sliver duct 16. The invention addresses this problem. In Figures 2 to 4; a recess 39, in which an optical sensor 40 is fastened, is arranged on the underside of the carrier plate 30. The optical sensor 40 has a transmission unit 47 and a reception unit 48, see Figure 4. Figure 4 illustrates, furthermore, an electrical connection 49 for the optical sensor 40. The electrical connecting leads are not reproduced in the drawing. The transmission unit 47 emits light beams, preferably in the visible or infrared wavelength range, and receives a signal when light beams in the light cone are rejected on a reflecting material. The recess 39 has provided in it, furthermore, a pneumatic device 41 which has, in the direction of flow, a compressed-air connection 43, a compressed-air duct 42 and a blowing orifice 44, the latter being directed onto the surface of the optical sensor 40 and the space in front of the sensor surface. The pneumatic device 41 may be operated, for example, continuously or in the pulsed mode and serves for preventing fibre fly from being deposited on the sensor surface. The pneumatic device 41 is advantageously connected mechanically to the optical sensor 40, so that only the pneumatic device 41 has to be fastened to the carrier plate 30 by means of screws 45, see Figure 4. It may likewise be gathered from Figure 4 that two screws 46 for fastening the optical sensor 40 to the pneumatic device 41 are provided. The optical sensor 4 0 functions as follows. The beam path of the transmission unit 47 runs essentially parallel to the fibre-sliver transport direction (see arrow 38 in Figure 3) through the sliver funnel 33. By background blanking-out, the optical sensor 40 detects only fibre sliver FB' within a light cone of defined length. This light cone extends beyond the calender rollers 13, 14, but not as far as the turntable portion lying underneath them. In fault-free sliver production operation, therefore, there is no reflecting material in the light cone of the transmission unit 47. In the event of a sliver build-up in front of the sliver duct 16, however, fibre sliver FB' emerges at the sides of the sliver-duct inlet and passes into the said light cone. The reflections from this built-up fibre-sliver material are received by the reception unit 48 of the optical sensor 40 which generates an electrical signal. This signal is ultimately used for switching off the machine by means of a switch-off mechanism not illustrated in any more detail. By the machine being switched off, sliver conveyance is interrupted, so that the sliver build-up in front of the sliver duct 16 or the turntable 17 does not become even larger and therefore fibre-sliver rejection is kept within limits. Figures 5 to 7 illustrate a further embodiment of a sliver build-up sensor in the region of the outlet of the sliver funnel 33. The carrier plate 30 is in this case identical to that according to Figure 5. The sliver build-up sensor 50, operating on the mechanical principle, is of essentially elongate design and comprises essentially three parts, to be precise a bearing element 52, a switching element 54 and a deflection element 58. The essentially cylindrical elastic bearing element 52 is screwed in a recess 39 on the underside of the carrier plate 30, the said recess corresponding to the recess 39 according to Figures 2 to 4, by means of a screw 53 which is introduced through a bore from the top side of the carrier plate 30. The bearing element 52 is manufactured from a non-conductive material. A bell-shaped metallic switching element 54 is slipped over the bearing element 52 from the underside of the carrier plate 30, but, in the state of rest, has no contact with the metallic carrier plate 30. The gap width between the annular edge of the switching element 54 and the recess 39 is approximately 0.1 to 0.3 mm, measured in the transport direction of the fibre sliver FB' (see arrow 38). This gap width or this switching distance is marked by the arrows 51 pointing towards one another. The lateral distance of the switching element 54 from the side walls of the recess 39 is greater than the switching distance, in order to avoid contact of the bell wall with these side walls. The switching element 54 has, in the region of its bell cowl, a central perforation which is in alignment with a blind bore in the bearing element 52. Fastened into these orifices is a spike 55, the other free end of which projects out of the bell and onto which a deflection element 58 designed as a helical spring is slipped. Attached over the spike 55 and the helical spring 58 is a shrink hose 57, in order, in particular, to keep fibre fly away from the turns of the helical spring 58. In the event of the deflection of the helical spring or of the deflection element 58, the switching bell 54 is also deflected. If the deflection exceeds a particular amount, the top edge of the switching bell 54 touches the underside of the metallic carrier plate 30 in the region of the base surface of the recess 39. The carrier plate 30 is, for example, at negative electrical potential, whilst the metallic switching element 54 is connected to a positive potential. For this purpose, according to Figure 7, an electrically insulated cable 60 projects through a horizontally running bore in the carrier plate 30. The cable 60 issues into a metallic cord 61 which is fastened to the switching element 54, with electrical contact, by means of a screw 62, In the event of a sliver build-up in the region of the sliver-duct inlet, the deflection element 58 is deflected laterally out of its vertical position, so that, as described, the switching bell 54 makes electrical contact with the metallic carrier plate 30. The electrical signal generated thereby is used in a switch-off mechanism in order to shut down the machine. After the sliver build-up has been removed, the deflection element 58 pivots back into its vertical initial or rest position by virtue of the elasticity of the bearing element 52 and of the deflection element 58. The electrical contact between the carrier plate 30 and the switching bell 54 is thereby broken again. In an alternative embodiment, not illustrated, the bearing element 52 and the deflection element 58 are produced in one piece. So that it is easy for the deflection element 58 to be pivoted away for simpler operator access, the spring constant of the combined bearing and deflection element may advantageously be varied over its length. The spring constant is preferably greater at the end located on the carrier-plate side than at the end remote from the carrier plate. Since the bearing element 52 serves as insulation between the carrier plate 30 and the switching element 54, it is designed to be electrically non-conductive. Various materials, for example rubber, elastomers, or else a spring, are appropriate in this case. Nor is the use of a spring absolutely necessary for the deflection element 58. Instead of a spring, for example, an elastic rubber material or else a rigid material may be selected. In the latter instance, an elastic bearing element 52 must be selected. Instead of a shrinkage hose, the deflection element 58 may also have an injection-moulded surface. The mechanical sliver sensor according to the invention may also be used on other textile machines as drawframes, for example on cards or combing machines. Furthermore, instead of the closing or, alternatively, the breaking of a circuit as a result of contact between two metal parts in order to generate a shutdown signal, an induction signal may also be generated in a corresponding induction unit, in a similar way to the prior art described in the introduction. 1. Drawframe for the drawing of at least one fibre sliver (FB) , with a drawing mechanism (4), with a sliver funnel (33) following the drawing mechanism (4) and with a pair of calender rollers (13, 14) which is located further downstream and which draws off the fibre sliver (FB') drawn in the drawing mechanism (4) through the sliver funnel (33), transports it into a sliver duct (16) arranged downstream of the pair of calender rollers (13, 14) and finally deposits it into a spinning can (18) , and also with a sensor (40; 50) which, in the event of a sliver build-up at the inlet of the sliver duct (16), generates a signal for switching off the sliver transport, characterized in that the sensor (40; 50) is arranged in the region of the sliver-funnel outlet. 2. Drawframe according to Claim 1, characterized in that the sensor (40; 50) is arranged on a carrier plate (30) for sliver guide elements, in particular a carrier plate (30) for the sliver funnel (33). 3. Drawframe according to one of the preceding claims, characterized in that the sensor (40; 50) is arranged on the underside of the carrier plate (30) laterally next to the sliver-funnel outlet. 4. Drawframe according to one of the preceding claims, characterized in that the sensor (40; 50) is mounted in a recess (39) on the carrier-plate underside. 5. Drawframe according to one of the preceding claims, characterized in that the sensor (40; 50) is designed as an optical sensor (40). 6. Drawframe according to one of the preceding claims, characterized in that the optical sensor (40) comprises a transmission unit (47) and a reception unit (48) in a common housing. 7. Drawframe according to one of the preceding claims, characterized in that the optical sensor (40) for the emission of beams is oriented essentially in the fibre-sliver transport direction (38). 8. Drawframe according to one of the preceding claims, characterized in that the sensor (40) responds to reflections from the fibre sliver (FB' ) when the fibre sliver (FB') is deflected out of its intended transport direction (38) in the event of a sliver build-up. 9. Drawframe according to one of the preceding claims, characterized by a pneumatic device (41) , the blowing stream of which is directed onto the sensor surface and/or onto the space in front of the sensor surface. 10. Sliver build-up sensor for a textile machine, in particular a drawframe according to one of Claims 1 to 4, with a deflection element (58) deflectable out of its rest position into an alarm position in the event of a sliver build-up, an electrical pulse for shutting down the drawframe being capable of being generated in the alarm position, characterized in that the deflection element (58) is of essentially bar-shaped or sheet-like design and can be oriented essentially in the fibre-sliver transport direction (38), 11. Sensor according to Claim 10, characterized in that the deflection element (58) is designed elastically and/or is mounted in an elastic bearing element (52) in such a way that it can automatically pivot back into its rest position when the sliver build-up is eliminated. 12. Sensor according to Claim 10 or 11, characterized in that the deflection element (58) and/or the bearing element (52) is designed as a spring, rubber buffer, elastomeric buffer or the like. 13. Sensor according to one of Claims 10 to 12, characterized in that the deflection element (58) and/or the bearing element (52) is coupled to a metallic switching element (54) which, in the event of a sliver build-up, can also be deflected and causes the said electrical pulse. 14. Sensor according to one of Claims 10 to 13, characterized in that the deflection element (58) is mounted in an elastic non-conductive bearing element (52) which itself can be fastened to a carrier plate (30) . 15. Sensor according to one of Claims 10 to 14, characterized in that the switching element (54) is of bell-shaped design, and, in the event of the deflection of the deflection element, the metallic bell wall is also deflected in order to generate the electrical pulse- 16. Sensor according to one of Claims 10 to 15, I characterized in that the bearing element (52) is arranged on the inside of the bell-shaped switching element (54), and the deflection element (58) is arranged on the switching element (54) on the outside. 17. Sensor according to one of Claims 10 to 16, characterized in that the bearing element (52) and the deflection element (58) are connected to one another through an orifice in the switching element (54). 18. Drawframe according to one of Claims 1 to 4, with a mechanical sensor (50) comprising a deflection element (58) which can be deflected by the fibre sliver (FB') in the event of a sliver build-up. 19. Drawframe according to Claim 18, characterized in that the mechanical sensor (50) is designed according to one of Claims 10 to 17. 20. Drawframe according to Claim 18 or 19, characterized in that, with deflection in the event of a sliver build-up, the switching element (54) comes into contact with a metal contact on a carrier plate (30), in particular a carrier plate (30) for the sliver funnel (33), in order to generate an electrical pulse. 21. Drawframe according to one of Claims 18 to 20, characterized in that, in the rest position of the deflection element (58) , the switching element (54) has a switching-contact distance of approximately 0.1 to 0.3 mm from the metallic carrier plate (30) in the fibre-sliver transport direction (38). 22. Drawframe, substantially as hereinabove described and illustrated with reference to the accompanying drawings.

Documents:

588-che-2003 abstract granted.pdf

588-che-2003 claims granted.pdf

588-che-2003 description (complete) granted.pdf

588-che-2003 drawings granted.pdf

588-che-2003-abstract.pdf

588-che-2003-claims.pdf

588-che-2003-correspondnece-others.pdf

588-che-2003-correspondnece-po.pdf

588-che-2003-description(complete).pdf

588-che-2003-drawings.pdf

588-che-2003-form 1.pdf

588-che-2003-form 18.pdf

588-che-2003-form 3.pdf

588-che-2003-form 5.pdf