Title of Invention

DRAFTING SYSTEM FOR A SPINNING MACHINE

Abstract

Drafting equipment for a spinning machine, especially a regulating draw equipment, with at least two consecutive roller pairs, with several electrical motors (10,20) for driving respectively at least one roller (2,3,4) of said roller pairs and with an electronic control (5) to which the electrical motors (10, 20) are connected characterized by the fact that at least to one electrical motor (10, 20)and/or at least to one roller (2,3,4) one acceleration sensor (12,22) is allocated.

Full Text

FORM 2 THE PATENT ACT 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10, and rule 13) TITLE OF INVENTION DRAFTING ARRANGEMENT FOR A SPINNING MACHINE APPLICANT(S) a) Name : RIETER INGOLSTADT SPINNEREIMASCHINENBAU AG b) Nationality : GERMAN Company c) Address : FRIEDRICHEBERT-STRASSE 84, D-85055 INGOLSTADT, GERMANY PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - Description DRAFTING ARRANGEMENT FOR A SPINNING MACHINE The invention relates to a drafting arrangement for a spinning machine, especially an auto leveler draw frame with at least two roller pairs in sequence, with several electrical motors for driving at least one roller from the said roller pairs per motor and with an electronic control to which the electrical motors are connected. In case of controlled drafting arrangements an accurate synchrony of roller pairs of the drafting arrangement is of critical significance for the quality or evenness of the produced sliver(s). Mechanical couplings via gears or belt drives are very much ideal for this, since these ensure the basic synchrony of the roller pairs. For automation purposes, however, these are not optimum suitable. The deployment of several direct drives, so-called individual drives for driving the drafting equipment components, offers the possibility to automate the machine settings of drafts and tensioning ratios. Drafting arrangements with that kind of individual drives are known for a longer time. In known designs incremental shaft encoders for calculating the rpm, rotary speed, angle of rotation etc. are allocated to the motor shafts of drives or to roller shafts. The shaft encoders for this purpose are developed as digital position (angle) sensors from position signals of which (number of rotations per specified time window) information on speed and rpm is received, which can be referred to with the help of a respective allocated motor controlling device for adjustment of respective motor rpm. The disadvantage of these traditional drive systems consisting of a position and rpm control using incremental shaft encoder is that the signal formation for digital postprocessing requires time. During this time period there are no current values available and one must interpolate. For the drive this means a certain play in the motor shafts, which is very disturbing for the synchrony in the dynamic range and the rigidity to disturbance is heavily impaired. Disturbances on the motor shafts occurring due to load changes, belt vibrations, etc. thereby cannot be effectively eliminated. The result is impaired smoothness of running in constant run and asynchrony between the drafting equipment rollers. It is, therefore, the task of the present invention to create a drafting equipment of the kind mentioned at the beginning, which avoids the said disadvantages and ensures especially an improved draft. This task is resolved in the drafting equipment of the type mentioned at the outset in a way that an acceleration sensor is assigned to at least one electrical motor and/or at least to a roller. The advantages of the invention are to be seen especially in the fact that a real time signal regarding acceleration is received, which directly registers load moment changes, i.e. disturbing influences. These disturbance parameters include thick spots registered by the scanning gear fitted in-line with the drafting equipment and the elasticity of drive belts along with their vibrations. The load moment changes cause positive or negative accelerations of motor shaft, which can be directly registered by acceleration sensor. The signals outputted by the sensor can then be directly processed in order to readjust the motor current. Since, in contrast to the usage of incremental position sensors no time consuming processing of signals is essential, a direct, quick and precise controlling of motor is possible. Thus an even and constant run of roller pairs can be achieved, which is superior to the traditional drives. If the acceleration information is processed with the help of known incremental shaft encoder, it would take a considerable time. Besides, errors can be induced through the necessary differentiation of encoder signals, which negatively influence the control quality. As against this it is also possible to receive speed or rpm values through integration, wherein the necessary computing operations cause less number of errors than the so-called differentiations. An added advantage of the deployment of acceleration sensors is their high sensitivity with relatively higher robustness at the same time. Especially preferred the said at least one acceleration sensor is developed as relative acceleration sensor, since this does not consider the disturbing influence of earth acceleration. As a special, well suited relative acceleration sensor the so-called Ferraris sensor has proved itself, which is based on the principle of eddy current and possesses a very high dynamics. In a preferred design at least one acceleration sensor is arranged at a shaft of an electrical motor and it thus directly obtain at the shaft the real time signals for acceleration of this shaft. In this case, on deployment of a Ferraris sensor only then signals are outputted when the roller experiences a relative acceleration. In an alternative the acceleration sensor is arranged at a shaft of a roller. The time advantage gained by means of acceleration sensor can be retained if quick switching analogue and/or digital switching components are used - mainly prompt -signal evaluation of said sensors and their conversion in current signals for the motors. Advantageously one each of motor control equipment is allocated to electrical motors. This covers especially preferred an rpm regulator and a downstream current regulator for the respective motor. In this kind of arrangement, for example, from incremental shaft encoder (encoder with barcode discs, resolver based on the transformer principle, Sincos encoder) position and rpm signals of the motor (or also of a roller shaft driven by the motor) are captured. These actual signals are then transferred to the rpm regulator, which then compares these with the target values of regulating equipment. The output signal of the rpm regulator is transferred as target value to the current regulator, which additionally receives from the motor its present current-actual-value. In addition, according to the invention an acceleration sensor is provided at a suitable spot on the motor, preferably on its driven side. The signals of the acceleration sensor can then be transferred directly to the current regulator, to balance out short or quick load changes. Especially preferred, the signal of the acceleration sensor is used in its analogue form, i.e. without analogue-digital conversion and the signal of the motor equipment is transferred to the current regulator. In case of this kind of direct transfer of signals of acceleration sensor the current regulator is developed purposefully as hybrid regulator, which can process analogue as well as digital signals (latter are especially the output signals of the rpm regulator). The use of analogue acceleration values or proportional to these voltage values of at least one acceleration sensor has the advantage that these signals can be processed in real time. Alternative to a transfer of acceleration signals to the motor equipment and - herein preferably - to the current regulator, these can also be transferred to regulating equipment, also herein preferably but not necessarily in analogue form. In addition, a tacho generator for exact rpm metering can be allocated to one of the electrical motors, wherein the preferably analogue signals of tacho generator obtained in real time are preferably switched to at an input of the rpm regulator. Also with this tacho generator short or quick rpm changes can be captured at the motor shaft and can go into the rpm regulation. Also in case of slow rpm more precise rpm values can be measured in analogue form rather than with a digital and therefore, with stepped working shaft encoder. For the evaluation of these analogue signals the rpm regulator is also developed preferably as hybrid regulator. In place of deployment of hybrid regulators, which ensure capture of disturbance parameters without time loss, the analogue signals can also be processed by analogue modules, especially amplifying, weighing and evaluating etc. Advantageous further developments of the invention are characterized by the features of sub-claims. The invention is explained on the basis of figures below. These are: Figure 1 a schematic plane view of an invention based drafting equipment, and Figure 2 a block circuit diagram of a motor regulating equipment. In Figure 1 schematically invention based regulating drafting equipment 1 has been shown, which covers an entry roller pair, a middle roller pair and an exit roller pair. In Figure 1 only the bottom rollers of these pairs are shown, i.e. the entry bottom roller 2, the middle bottom roller 3 and the exit bottom roller 4. Only these bottom rollers 2, 3, 4 are driven, whereas the top rollers not shown are pressed on the respective bottom rollers 2, 3, 4, so that the schematically indicated sliver(s) FB is/are clamped between the roller pairs. Both the bottom rollers 2, 3 are driven by a common electrical motor 10, which causes a specified pre-draft via a gear stage (not shown in more details) with belt drives 6 between the entry and middle roller pair. The exit bottom roller 4 is driven by a separate electrical motor 20 via belt drive 7 (not shown in more details). The rpms of electrical motors 10, 20 can be regulated by means of a regulating equipment 5 in a manner that a draft of the sliver(s) FB balancing the fluctuations of the sliver mass is implemented between the middle and exit roller pair. For this purpose the regulating equipment 5 receives sliver mass signals or sliver cross section signals from measuring equipment located upstream in the drafting equipment not shown here. The regulating equipment 5 can be developed as microcomputer, which takes over besides the electronic control also the machine control. To each of electrical motors 10, 20 a separate electronic motor control 13 and 23 are allocated, which are connected through wires 8 and 9to the regulating equipment 5 and receive from this target values with respect to motor rpm. The motor regulating equipment 13 and 23 are respectively connected through wires 18 and 28 with the respective electrical motor 10, 20. Further, to the electrical motors 10 and 20 respectively one incremental shaft encoder 11 and 21 are connected through wires 16 and 26, which is developed - for example - as known encoder or resolver and serves the purpose of capturing the rpms of respective motor shaft. During one shaft rotation approx. 100 pulses are outputted by the incremental encoder 11 and 21, so that from the pulses within a specified time window as well as the position of the motor rotor a conclusion regarding rpm per time unit of the respective shaft can be drawn. The digital signals of shaft encoders 11 and 21 are transmitted by means of wires 17 and 27 to the respective motor control equipment 13 and 23 and there these are referred to for setting the motor current of the electrical motors 10, 20. Further, to electrical motors 10 and 20 as per invention an acceleration sensor 12 or 22 is respectively allocated, which are developed here as relative acceleration sensors, for example, as Ferraris sensors. The acceleration sensors 12 and 22 are allocated via wires 14 and 24 to the respective motor shafts of electrical motors 10, 20, wherein the acceleration sensors 12 and 22 transmit highly dynamic acceleration signals in the form of Actual voltage values via wires 15 and 25 to the respective motor control equipment 13 and 23. The acceleration sensors 12, 22 provide preferably only signals, if actually positive or negative accelerations occur at the motor shafts. These are effected by the load changes, which cause changes in the load moment and thereby in the motor rpm. The analogue acceleration signals of acceleration sensors 12, 22 can now onwards be referred directly as real time signals for current control of electrical motors 10, 20. The combined evaluation of position values measured by means of incremental shaft encoder 11 and 21 and acceleration values of sensors 12 and 22 ensures a precise, quick motor control, especially in the event of fast and/or short load changes. Overall the quality of control can thus be considerably improved. In Figure 2 a block circuit diagram of a motor control equipment 13 is shown, wherein this equipment 13 is structured analogue to motor control equipment 23. the motor control equipment 13 covers a rpm controller 34 and a downstream current controller 36, wherein the latter is connected with the electrical motor 10 through the wire 18 and transmits a current target value to this. To the motor 10 on the one hand the said acceleration sensor 12 and on the other hand through wire 31 a tacho generator 30 (not present in the design example of Figure 1) is allocated. The tacho generator calculates the Actual rpm of the motor shaft and forwards its analogue output signal through wire 32 to the rpm controller 34. the rpm controller 34 receives further digital signals from the incremental shaft encoder 11 as well as via the wire 8 a rpm target value "Target" from the regulating equipment 5. Since the rpm controller 34 thus processes analogue and digital signals, it is developed as hybrid controller. Its output signals are transferred via a wire 35 to the current controller 36, which also receives via a wire 37 the current actual value of the motor 10 and via the wire 15a voltage value from acceleration sensor 12. the acceleration value (in case if at the moment there is an acceleration) is proportional to the present acceleration value. Advantageously, these voltage values in analogue form are transferred directly to the current controller 36, so that appropriately this is also developed as hybrid controller. Further, the current controller 36 receives through a wire 38 the information "Max" for the maximum permissible motor current. The motor control equipment 13 along with the rpm controller 34 and the current controller 36 has preferably fast switching, analogue and digital switching parts to be able to undertake the signal evaluation and the conversion in current signals as far as possible free of disturbance. Preferably the motor control equipment 13 is controllable through software. The above designs of motor control equipment 13 are applicable analogue for the motor control equipment 23. The involved electrical motors can work either in master-slave mode or in parallel target value mode. Without deviating from the basic thought of the invention - as laid down in the claims - other individual drive arrangements are possible. We Claims 1. Drafting equipment for a spinning machine, especially a regulating draw equipment, with at least two consecutive roller pairs, with several electrical motors (10, 20) for driving respectively at least one roller (2, 3, 4) of said roller pairs and with an electronic control (5), to which the electrical motors (10, 20) are connected characterized by the fact that at least to one electrical motor (10, 20) and/or at least to one roller (2, 3, 4) one acceleration sensor (12, 22) is allocated. 2. Drafting equipment as per Claim 1 characterized by the fact that the minimum one acceleration sensor (12, 22) is developed as relative acceleration sensor. 3. Drafting equipment as per Claim 2 characterized by the fact that the minimum one acceleration sensor (12, 22) is a Ferraris sensor. 4. Drafting equipment as per previous claims characterized by the fact that the minimum one acceleration sensor (12, 22) is arranged on a shaft of at least one electrical motor (10, 20). 5. Drafting equipment as per one of the Claims 1 to 3 characterized by the fact that the minimum one acceleration sensor (12, 22) is arranged at a shaft of a roller (2, 3, 4). 6. Drafting equipment as per one of the above claims characterized by quick switching, analogue and/or digital switching parts (13, 23) for signal evaluation (as far as possible without delay) of minimum one acceleration sensor (12, 22) and their conversion in current signals for the respective motor (10, 20). 7. Drafting equipment as per one of the previous claims characterized by the fact that to the at least one electrical motor (10, 20) and/or the at least one roller (2, 3, 4) one incremental shaft encoder (11, 21) is allocated for recording the rpm, the direction of rotation and/or angle of rotation. 8. Drafting equipment as per one of the previous claims characterized by "the fact that to the at least one electrical motor (10, 20) a separate motor control equipment (12, 23) is allocated. 9. Drafting equipment as per Claim 8 characterized by the fact that the motor control equipment (13, 23) covers a rpm controller (34) and a current controller (36) for the minimum one electrical motor (10, 20). 10. Drafting equipment as per one of the previous claims characterized by the fact that the signals of the acceleration sensor (12, 22) allocated to the at least one t electrical motor (10, 20) are transferred to the controlling equipment (5) or to the motor control equipment (13, 23), preferably to an input of the current controller (36). 11. Drafting equipment as per Claim 10 characterized by the fact that signals of acceleration sensor (12, 22) allocated to the electrical motor (10, 20) are transferred in analogue form without previous analogue-digital conversion. 12. Drafting equipment as per one of the previous claims characterized by the fact that a tacho generator (30) is provided for calculating the rpm of the at lest one electrical motor (10, 20). 13. Drafting equipment as per Claim 12 characterized by the fact that the signals of the tacho generator (30) are transferred to the motor control equipment (13, 23) preferably at the input of the rpm controller (34). 14. Drafting equipment as per Claim 12 or 13 characterized by the fact that the tacho generator (30) transmits analogue signals Dated this 10th day of March, 2006. ASEAN SAARC PATENT & TRADE MARK SERVICES AGENT FOR RIETER INGOLST ADT SPINEREIMASCHINENBAU AG

Documents:

398-MUMNP-2006-ABSTRACT(01-09-2008).pdf

398-mumnp-2006-abstract(granted)-(27-10-2008).pdf

398-mumnp-2006-abstract-1.jpg

398-MUMNP-2006-CANCELLED PAGES(01-09-2008).pdf

398-MUMNP-2006-CLAIMS(01-09-2008).pdf

398-mumnp-2006-claims(complete)-(7-4-2006).pdf

398-mumnp-2006-claims(granted)-(27-10-2008).pdf

398-mumnp-2006-claims.pdf

398-mumnp-2006-correspondance-po.pdf

398-mumnp-2006-correspondance-received.pdf

398-MUMNP-2006-CORRESPONDENCE(01-09-2008).pdf

398-mumnp-2006-correspondence(17-10-2006).pdf

398-mumnp-2006-correspondence(ipo)-(7-11-2008).pdf

398-mumnp-2006-description (complete).pdf

398-MUMNP-2006-DESCRIPTION(COMPLETE)-(01-09-2008).pdf

398-mumnp-2006-description(complete)-(7-4-2006).pdf

398-mumnp-2006-description(granted)-(27-10-2008).pdf

398-MUMNP-2006-DRAWING(01-09-2008).pdf

398-mumnp-2006-drawing(7-4-2006).pdf

398-mumnp-2006-drawing(amended)-(1-9-2008).pdf

398-mumnp-2006-drawing(granted)-(27-10-2008).pdf

398-MUMNP-2006-FORM 1(01-09-2008).pdf

398-mumnp-2006-form 1(7-4-2006).pdf

398-mumnp-2006-form 18(1-9-2008).pdf

398-mumnp-2006-form 18(7-4-2006).pdf

398-mumnp-2006-form 2(01-09-2008).pdf

398-mumnp-2006-form 2(complete)-(7-4-2006).pdf

398-mumnp-2006-form 2(granted)-(27-10-2008).pdf

398-MUMNP-2006-FORM 2(TITLE PAGE)-(01-09-2008).pdf

398-mumnp-2006-form 2(title page)-(complete)-(7-4-2006).pdf

398-mumnp-2006-form 2(title page)-(granted)-(27-10-2008).pdf

398-MUMNP-2006-FORM 3(01-09-2008).pdf

398-mumnp-2006-form 3(7-4-2006).pdf

398-MUMNP-2006-FORM 5(01-09-2008).pdf

398-mumnp-2006-form 5(7-4-2006).pdf

398-mumnp-2006-form-1.pdf

398-mumnp-2006-form-2.doc

398-mumnp-2006-form-2.pdf

398-mumnp-2006-form-3.pdf

398-mumnp-2006-form-5.pdf

398-MUMNP-2006-GENERAL POWER OF ATTORNEY(01-09-2008).pdf

398-mumnp-2006-general power of attorney(7-4-2006).pdf

398-MUMNP-2006-OTHER DOCUMENT(01-09-2008).pdf

398-MUMNP-2006-PCT-IB-338(01-09-2008).pdf

398-MUMNP-2006-PCT-IB-373(01-09-2008).pdf

398-MUMNP-2006-PCT-ISA-237(01-09-2008).pdf

398-mumnp-2006-specification(amended)-(1-9-2008).pdf

398-mumnp-2006-wo international publication report(7-4-2006).pdf