Title of Invention: Spin machine with several single drives
Abstract: 
In a spinning machine with at least one spinning station (1) which station possesses a feed drum (2), driven by a single drive (12), a disintegrator (3), a rotor (4), a withdrawal roll (5) and a spool roll (7), provision has been made, that the spinning station (1) has an additional single drive (15, 16, 17) respectively for the withdrawal roll (5) and/or the spool roll (7) and/or a paraffin roll (6) and that the speed of rotation ratio of the single drives (12, 15, 16, 17) can be preset to specified values. 

Summary of Invention: 
&lsqb;0001&rsqb; The invention concerns a spinning machine with at least one spinning station, which station possesses a feed drum driven by a single drive, a disintegrating roll, a rotor, a withdrawal roll and a spool roll. 
&lsqb;0002&rsqb; EP 0 385 530 discloses such a spinning machine, in which the feed drum of each spinning position of an open-end spinning machine is driven by means of a stepping motor. A control system with an associated computer regulates the corresponding stepping motor in each spinning machine in accord with its direction of rotation, its speed of rotation and the angular position of the drive, and thereby also the feed drum. A control system for each of the stepping motors is advantageous, so that the necessary precision in regard to the feed of the fiber band is assured. 
&lsqb;0003&rsqb; In the conventional spinning machines, normally, the rotating elements which follow the feed drum in the direction of the band movement, for example, the rotor, are centrally driven by means of motors provided on an end of the spinning machine. In order to achieve the necessary correlation of the speed of rotation, for instance, of the feed roll, the withdrawal roll, and the spool roll, it is usual to provide electrically controlled, mechanical gear drives. By this means, each spinning station can produce constant thread quality where thread diameter and strength is concerned. Such gear drives possess, however, a great number of points of abrasion, which give rise to a relatively substantial demand of expense and maintenance time. Additionally, a relatively large startup momentum can be attributed to these gear drives. Where the necessary electrical control is concerned, considerable costs are involved in the wiring and its installation. 
&lsqb;0004&rsqb; Thus, it is the purpose of the invention, to make available a spinning machine of the kind mentioned in the introductory passages, in which is made possible a simple, and therefore precise, drive of the individual rotational elements of a spinning station. 
&lsqb;0005&rsqb; This purpose, in the case of the spinning machine of the kind mentioned in the introductory passages, is achieved, in that the spinning station exhibits, respectively for the withdrawal roll, and/or the spool roll, and/or the waxing roll, an additional single drive, and that the rotational ratios of the single drive can be set to specification. 
&lsqb;0006&rsqb; The advantage of the invention can be particularly seen in that—besides each feed drum—an individual drive has been assigned to each withdrawal roll, and/or to the spool roll, and/or to for waxing roll. Since the rotational ratios of the individual drives of each spinning station can be specified, an optimized correlation in regard to synchronization, operational life, and rotational speed is assured. Furthermore, by means of the installation of the single drives, expensive, and thereby damage-prone gear drive construction is avoided, which otherwise would extend itself over the entire length of the spinning machine. Another advantage is that with this single drive, a very low degree of nominal torque is present, because of the small friction to which the individual drives are exposed. Especially, no torsional delays occur upon the startup of the respective rotational elements of the spinning stations, which are situated remotely from the central motor. A single drive, as an example, is also advantageous for the withdrawal roll, since this, upon spin-startup is driven in reverse direction, so that the spinning startup process is made substantially more easy. 
&lsqb;0007&rsqb; Advantageously, one of the individual drives serves as a lead motor. This has a specified guiding rotational speed or a specified guide frequency, to which is related the rotational speed of at least one single drive, and preferably, where multiple drives are concerned, the rotational speeds of all other single drives. In this manner, the RPM of all other single drives refers back to the said lead drive and the rotational speeds of the other drives can thus be preset. 
&lsqb;0008&rsqb; Particularly advantageously, the feed motor of the feed drum is designated to be the guide motor, since first, this rotates at a relatively low rotational speed (1-150 RPM) and second, must hold to the currently set rotational speed with great precision. Even small deviations lead to an undesirable variation of the set values of the thread to be spun. Although the single drive of the feed drum is chosen as the lead motor, this is not dependent upon the guidelines of other drives. Much more, rotational speed of the lead motor can be directly and precisely adjusted. Because of the mentioned achievable exactness of its rotational speed, with an appropriate ratio control, a uniform torque for the other single drives is possible in all RPM ranges. 
&lsqb;0009&rsqb; In an advantageous manner, for each spinning station, only one power control center for the regulation and the supply of electrical current to the individual drive need be provided. This design has the advantage, that the electronic circuitry need be installed only once, since this serves in common for all individual drives per spinning station. On this account long cable hook-ups from a central network, which then must run along the entire spinning machine, are no longer necessary. 
&lsqb;0010&rsqb; In order to further reduce extensive constructional work and wiring, the power control center is placed on or near one of the individual drives. For instance, the power control center is screwed within or onto the housing of the feed drum. For the wiring thereof, corresponding borings are made through the housing. From the power control center, the additional control and power lines run to the other individual drives. Principally, the power control center can be provided at any of the other individual drives. For the eventual placement, the spatial conditions in the spinning station must be taken into consideration, so that, besides space saving, maintenance and cleaning services can be carried out with good accessibility. 
&lsqb;0011&rsqb; The rotational speed of the other single drives, in relation to the lead motor, is advantageously effected by a frequency generator. For instance, there is respectively one frequency generator between the power control center, to which the lead motor is connected, and any of the single drives which is to be controlled. Alternatively, simply a single frequency generator can be furnished which transmits to the individual drives, by means of a frequency divider, the rotational speed commands based on those of the lead motor. 
&lsqb;0012&rsqb; The invention allows, that a very fine subdividing of the motor rotation speed for the lead motor and/or the individual drives, may be undertaken in micro-stepping, so that practically, feedback-free operation of this motor is possible. 
&lsqb;0013&rsqb; Particularly advantageous is to design at least one of the single drives as a stepping motor. Stepping motors have the advantage, that they possess only very few parts, and certainly no gear drives which are susceptible to wear and tear. Further, stepping motors possess the advantage, that, while maintaining high efficiency, a relatively small inertial moment is in effect, wherein, their shafts start to rotate without inrush current to the motor, that is, the motor can be quickly accelerated. In addition, stepping motors can be simply and precisely controlled and react very quickly to control commands. Further, stepping motors can be brought up to top speed on a continuous basis and in addition can be driven in the reverse direction. In regard to the economics, the stepping motor has no decisive disadvantage as compared to the synchronous motor. By the use of a stepping motor for the feed drum, this motor is preferable in a range of 1 to 150 RPM and can be run at a nearly constant torque. 
&lsqb;0014&rsqb; Especially at a paraffin roll, which serves for the waxing of the thread before the windup on the spool, the installation of a stepping motor is of advantage. Conventionally, for the drive of a paraffin roll, a synchronous motor is selected. On the grounds of the mechanical gear drive in such a motor, during startup of the roll, relatively great frictional forces must be overcome. To this purpose, the motor customarily calls for excess current. This characteristic increases the complexity of the control, i.e. of constant monitoring. Alternatively, a larger motor could be selected, which, however would have an even greater demand for kellykevin@example.com. By means of the selection of a stepping motor, all these problems are prevented. 
&lsqb;0015&rsqb; For the feed drum of each spinning station, the use of a stepping motor is likewise of advantage, as has already be made plain by the above description of the state of the technology. In particular, the doing away with extensive and failure-prone gear drives, as well as acquiring precision of the RPM even in the lower rotational speed ranges are advantages to be valued. 
&lsqb;0016&rsqb; This said precision permits running the spinning station as a “stand alone machine” with the corresponding demands for a high degree of precision. The installation of stepping motors for the individual drive of the withdrawal roll and/or the spool roll—if such individual drives are provided—is, because of the above mentioned grounds, also advantageous. 
&lsqb;0017&rsqb; In a particularly preferred embodiment of the invention, the stepping motor for the paraffin roll is regulated by the lead stepping motor of the feed drum, in that a power control center delivers a signal through the frequency generator and over a line to the stepping motor for the said paraffin roll. Should the feed drum, for instance, be turning at 10 RPM and if the frequency generator is set at a rotational speed ratio of 5:1, then the paraffin roll rotates at 2 RPM. In such an operation, advantageously, small micro-step subdivisions per motor revolution are not necessary. 
&lsqb;0018&rsqb; Advantageous developments of the invention are characterized by the features of the subordinate claims.

Detailed Description: 
&lsqb;0027&rsqb; Emerging from a (not shown) stretch works, the fiber band B makes its way to the feed drum 2, which is circumferentially and axially corrugated and which conveys the fiber band B to the disintegrator roll 3. 
&lsqb;0028&rsqb; Equipped with circumferential comblike teeth 13, the disintegrator separates the band B into individual fibers. By means of a funnel shaped conduit 14, and under a suction, the stream of individual fibers enters the rotor 4. The rotor 4 rotates, by means of a central drive for all rotors of the spinning machine, at speeds of rotation exceeding 100,000 RPM and spins the fibers into a thread F. This thread F is subsequently removed from said rotor by the withdrawal roll 5 together with roll 11 which exerts a rolling pressure on the withdrawal roll 5. After this the thread F is guided to frictional contact with the paraffin block 8 and then is transported by the paraffin roll 6, which turns at a low rate of speed. Continuing in motion the thread is finally wound onto a spool 10 which is axially supported by a rotating core 9. The spool 10 lies with its own weight against the spool roll 7 and obtains its rotational energy therefrom. 
&lsqb;0029&rsqb; The feed drum 2 is connected to an individual drive 12 designed as a stepping motor. In the embodiment presented in the figure, the withdrawal roll 5 is connected with a single drive 15, the paraffin roll 6 with a single drive 16 and the spool roll 7 with its own drive 17. The stepping motor for the feed drum 2, in the depicted embodiment, is designed a lead motor with a specifically set lead RPM or with a given lead frequency. This said lead RPM determines the RPM of the remaining drives 15, 16 and 17. The speed of rotation of the motor 12 is controlled by a power control center 20, which with the input of either the specified lead frequency or the lead speed of rotation of said motor 12, transmits the respective frequencies (or RPM's) to the said individual motors 15, 16, 17 by means of electrical lines 23, 25, 27. Between the power control center 20 and the individual drives 15, 16, 17, respectively, a frequency generator 22, 24, 26 is inserted into the circuit, for the purpose of presetting to specific values the speeds of rotation of the single drives 15, 16 17. 
&lsqb;0030&rsqb; The individual drives 15, 16 17 can be designed as stepping motors, in like manner to the individual drive 12 of the feed drum 2. Stepping motors have, in such an application, among other preferable features, the advantage that they possess no gear drives subject to wear and tear. The supposed disadvantage, that stepping motors must be directly controlled, was countered by the invention, in that simply a single power control center is provided, by means of which, the rotational ratios—derived from either the frequency or the RPM of a lead motor—can be preset to specified values. 
&lsqb;0031&rsqb; The single power control center 20 serves likewise for the power distribution to the individual drives 12, 15, 16, 17. Not only does this allow space to be saved within the spinning station, but also the expenditure in wiring and attendant labor within a spinning station can be held at a low level. The power control center 20 is, for instance, placed directly on the stepping motor 12 of the feed drum 2. possibly screwed onto the housing thereof. From this point the electrical control lines 23, 25 27 run respectively to the other individual drives associated with the given spinning station. The frequency generators 22, 24, 26 can likewise by incorporated into the power control center. 
&lsqb;0032&rsqb; In an embodiment which is not illustrated, another motor is proposed as lead motor instead of the individual motor 12 of the feed drum 2. In the case of additional, not shown, embodiments, besides the individual motor 12 for the feed drum 2, simply one or two of the individual drives 15, 16, 17 are foreseen as the drive of one or two of the rolls 5, 6, 7. Especially, the possibility exists of using an individual drive 16, designed as a stepping motor, for the paraffin roll 6 and to control this by the individual drive 12 for the feed roll 2 by means of the power control center 20 as well as with the frequency generator 24. In this manner, no problems will arise upon startup of the paraffin roll 6, since lesser frictional force is to be overcome than is the case with the conventionally employed synchronous motor. Thus an otherwise necessary, heavy inrush current at startup for the paraffin roll can be avoided. Moreover, a single drive 16 for the paraffin roll 6 shows little wear, so the maintenance and cleaning expenses are kept at a low level. 


{'app_number': '09747789', 'application_number': None, 'doc_number': '20010042365', 'publication_number': None, 'source_file': './application/2001/pa011122.xml', 'source_data': 'USPTO-Application'}