| Tension control system for converting packages of elastic thread -> Monitor Keywords |
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Tension control system for converting packages of elastic threadRelated Patent Categories: Winding, Tensioning, Or Guiding, Tension Control Or Brake, Supply Controlled, Feeder Associated With Coil, Slackness SensorTension control system for converting packages of elastic thread description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070138331, Tension control system for converting packages of elastic thread. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND [0001] One common method of unwinding thread from a cylindrical mandrel (or "package") in a manufacturing process is referred to as over end takeoff (OETO). It should be noted that the terms "thread" or "fiber" are used interchangeably throughout this document. One issue common with OETO is unacceptable variations in threadline tension. These variations in threadline tension may result in excess utilization of thread, breakage of the thread in the manufacturing process, or poor product quality. Further, most thread vendors' product OETO thread packages by rewinding an as spun roll. This step incurs additional processing and cost. [0002] Another common method of unwinding thread from a cylindrical mandrel (or "package") in manufacturing processes is referred to as "rolling takeoff" which works in a draft mode or draw. This method also may include unacceptable variations in threadline tension resulting in many of the same issues described above. [0003] The aforementioned problems make the processing of elastomeric threads problematic. Furthermore some applications (e.g., manufacturing of diapers and other personal care products) require the use of as-spun thread or fiber that is substantially finish-free. Therefore, a fast and reliable method of unwinding and feeding elastomeric thread from a package to a thread processing system is still needed in the art. SUMMARY OF THE INVENTION [0004] The present invention is a system, apparatus and method for tension control in a thread feeding system that provides a fast and reliable method for feeding elastomeric thread or fiber from a package to a thread processing system. One version of the present invention includes a thread feeding system including guide rolls configured to guide an elastomeric thread through a thread path of the thread feeding system and a driven elastomeric thread package holder. The thread feeding system also includes a variable-speed motor configured to drive the driven elastomeric thread package holder and a first-tension sensor configured to determine the tension on the thread. The thread feeding system also includes a first tension controller device configured to control a speed of the variable-speed motor. [0005] Another version of the present invention includes a method for controlling elastomeric thread tension in a thread feeding system for a manufacturing system. The method includes measuring a thread tension of a moving elastomeric thread and determining whether the moving thread has a tension that is out of range relative to a predetermined tension value. The method also includes controlling the speed of a driven elastomeric thread package holder and delivering the thread to a desired location in the manufacturing system. [0006] Finally, another version of the present invention includes a thread feeding system including guide rolls configured to guide an elastomeric thread through a thread path of the thread feeding system. The system also includes a driven elastomeric thread package holder and a variable-speed motor configured to drive the driven elastomeric thread package holder. The system includes at least one guide located less than 0.5 meter from the driven package holder; a first tension sensor configured to determine the tension on the thread; and a first tension controller device configured to control a speed of the variable-speed motor. Further, the speed of the variable-speed motor is adjusted to maintain the tension on the thread within a predetermined range of thread tension values. BRIEF DESCRIPTION OF THE DRAWINGS [0007] The foregoing and other features and aspects of the present invention and the manner of attaining them will become more apparent, and the invention itself will be better understood by reference to the following description, appended claims and accompanying drawings, where: [0008] FIG. 1 illustrates a plan view of an embodiment of a thread feeding system; and [0009] FIG. 2 illustrates a plan view of a second embodiment of a thread feeding system which feeds multiple threads. DETAILED DESCRIPTION OF THE INVENTION [0010] FIG. 1 illustrates a thread feeding system (40). As shown in FIG. 1, a package (10) is held by a driven elastomeric thread package holder (12). The package holder (12) is sized such that the package (10) may be placed on the holder (12). The package holder may be adapted to contact a core of an elastomeric thread package. Alternatively, the package holder may be adapted to contact the circumference of the elastomeric thread package. The thread or fiber (11) is then directed, in sequence, through a static guide (14) having a substantially circular orifice; a tension device (16) around which the fiber may be wrapped; and a driven take-up roll or set of rolls (18). The static guide (14) is typically an orifice whose inner surface can be a highly polished ceramic material. Such a surface can provide excellent wear resistance and low friction. The take-up roll or rolls (18) representing that part of the manufacturing process equipment to which the thread or fiber is being supplied, is/are rotated at a speed relatively higher than the elastomeric thread package holder (12), so as to provide the desired draft. [0011] The package holder (12) is connected to a variable-speed motor (24). A distance (d) between the package and the first static guide (14) may be relatively short, such as less than 1.00 meter, or less than 0.50 meter or less than 0.25 meter. These short distances may allow for compact thread feeding systems (40). During run, the thread is removed from the package (10) and the driven holder speeds up or slows down depending on the tension measured by the tension device (16) and a predetermined range of thread tension values. One or more additional guides (20), (22) for stabilizing the position of the threadline may be provided along the threadline. [0012] The following paragraphs give exemplary details of the operation of the drive and tension control apparatus in terms of guides (20), (22), tension sensor (16), motion sensor (26), and break sensor (28). [0013] The thread feeding system (40) may be attached to a central frame member to form a free standing process. Alternatively, the feeding system may be integrated into a manufacturing system such as an absorbent article manufacturing system. [0014] Alternatively one or more portions of the feeding system (40) may be integrated into the manufacturing system while other portions remain free standing. [0015] As illustrated in FIG. 1, a driven elastomeric thread package holder (12) holds a package (10) and rotates thereby feeding the thread off the package. After the thread comes off the package (10), the thread may be directed by static guides (14). If multiple threads are being used, a static guide (14) may be provided for each thread. Alternatively, if two packages (10) are held by one package holder (12), the two strands may pass through a single static guide (14), thereby treating the two or more strands as a single strand. Static guide (14) is preferably an orifice through which the thread passes. The static guides (14) may be substantially circular orifices. However, static guides (14) are not limited to having a circular orifice for directing the thread. As can be appreciated, alternative embodiments may use any known or appropriate guide device for directing the thread. [0016] Thread feeding system (40) includes a driven package holder (12) and a tension control device (30) that is used to increment, maintain or decrease the amount of tension in the elastomeric thread. The tension controller (30) is connected to a tension sensor (16). The tension sensor (16) determines a measure of the tension of the thread as the thread comes off the driven package holder (12) and generates a signal representative of that tension. [0017] The tension sensor (16) is positioned after the driven package holder (12) and in the thread path. The distance the thread travels between the driven package holder (12) and tension sensor (16) is preferably minimized. Reducing the distance the thread travels between driven package holder (12) and tension sensor (16) enables the thread feeding system (40) to better account for tension variations occurring at the point where the correction is being made (i.e., at the driven package holder (12)). A substantial distance between driven package holder (12) and tension sensor (16) may add additional tension variations not seen at the driven package holder (12). [0018] As shown in FIG. 1, guides (14), (20) and (22) may include a combination of static guides and captive rolling guides which direct the thread through the feeding system (40). Alternatively, any of the guides (14), (20), (22) may be eliminated from the feeding system (40) if an applications performance can be improved through the use of fewer guide rolls. [0019] After the thread passes through the static guides (14) the thread engages a guide roll (20) configured to direct the thread through the thread feeding system (40). Again, if multiple threads are being used, a guide roll (20) may be provided for each thread. If the thread feeding system (40) is supplying multiple thread groups to the manufacturing system, multiple thread feeding systems (40) may be added as shown in FIG. 2. [0020] Multiple tension sensors (16, 16') may be used to determine a net tension value for a group of threads. Multiple break sensors (28, 28') may be used to determine whether there is a break in any individual thread or fiber. In addition, multiple motion sensors (26, 26') may be added to determine whether individual threads are moving. Non-limiting examples of tension, breakage and motion sensors are also available from BTSR. Continue reading about Tension control system for converting packages of elastic thread... Full patent description for Tension control system for converting packages of elastic thread Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Tension control system for converting packages of elastic thread patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Tension control system for converting packages of elastic thread or other areas of interest. ### Previous Patent Application: Wire spool Next Patent Application: Yarn changing method in a warping machine with yarn changing unit Industry Class: Winding, tensioning, or guiding ### FreshPatents.com Support Thank you for viewing the Tension control system for converting packages of elastic thread patent info. 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