High speed transfer takeup

An apparatus for transferring material winding between spools. The apparatus includes spindels for positioning first and second spools in a co-planar arrangement with parallel axes of rotation. With the material initially secured to the base of a first spool with tape, a winding mechanism is energized to turn the spools. When the first spool is filled, a first sheave directs the incoming material to the second spool which is rotated at the rate of material supply. A tape applicator is then directed to apply a section of tape over the material, pressing it against the base of the second spool. A small wire is included on the base of the tape being applied. The applicator force on the wire against the material is designed to be sufficient to sever the material, separating the material on the first spool from the material being wound on the second.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to methods and apparatus for continuous winding of material at high speeds, and more particularly to an apparatus for transfer of material winding between spools wherein the spools are positioned in a co-planar configuration providing for material transfer to be accomplishing without crossing over a spool flange.

2. Description of the Prior Art

In order to maximize the economy of manufacture of elongated, spool wound material, it is necessary to configure the manufacturing process to allow continuous operation while transferring winding from a filled spool to an empty one. Shutting down the winding process to transfer between spools is time consuming and in some cases detrimental to product quality. For example, in the case of optical fiber production, the fiber is pulled from a molten billet of quartz by an apparatus called a draw machine. Disrupting or stopping the process is costly, since the drawing operation, once disturbed, must be started slowly and ramped back up to production speed. In addition to the lost time, material is wasted because the fiber made during the speed-increase ramp is largely thrown away. Because of this inefficiency, systems have been designed to accomplish a “flying transfer” wherein the fiber is wound onto an empty spool without stopping the drawing operation. U.S. Pat. No. 4,798,346 by Meyers et al. describes one such system wherein each spool has a mechanism called a collector. Meyers refers to the collector as a storage and clamping assembly, item 47 in reference to FIG. 7 of Meyers. The collector is embodied as two disk-like structures about the same diameter as the spool upon which the fiber is being wound. The collector disks are positioned adjacent a flange of each spool and rotate on the same axis as the flange and at the same velocity. Two spools are positioned in axial alignment, with their collector apparatus facing each other. During the winding process, both spools and collection assemblies are rotating at the same velocity. When the winding of fiber on one spool is complete, the distributor leads the fiber over the flange of the first spool and onto the collector assembly of the second spool. At this time the collector disks of the empty spool are open/spaced apart. A portion of the fiber is wound on an array of pins between the disks, whereupon the disks are clamped, securing the fiber. The distributor then guides the fiber over onto the empty spool and winding continues. A cutter is then extended to sever the fiber between the two spools, freeing the full spool for removal and replacement with an empty spool.

A variation of the collector system has the two spools radially offset. In this case, when the distributor moves the fiber onto the collector of the new spool, the fiber is clamped and quickly breaks due to the stretching action caused by relative motion of the collectors of the full spool and empty spool. A cutter bar can also be used in the system to sever the fiber between the spools. Once the fiber is broken, the transfer proceeds in the same manner as with axially offset systems.

Another variation of the collector system employs a snagger button mounted into the rotating portion of the spindel turning the spool. Upon transfer from a full spool to an empty spool, the distributor leads the fiber over the spool flange to the snagger button corresponding to the empty spool. On the next rotation of the spool, the snagger button snags the fiber and begins wrapping it around the empty spool. A cutter bar is extended and the fiber between the spools is cut.

A disadvantage of the above described methods of transferring fiber between spools is that the speed of the spools during transfer is not constant. The speed varies as the fiber is moved over the spool flanges and onto the base of the empty spool. In some designs, slots are cut in the flange for passing of the fiber in order to reduce the disturbance in fiber speed when the distributor leads the fiber over the flange. The slot, however, weakens the spool and increases its tendency to flex and distort, damaging the quality of the wound package. Both the collector mechanism and the snagger mechanism introduce large disturbances in the speed of the fiber as the fiber is suddenly grabbed. These sudden disturbances in the speed of the fiber greatly increase the tendency of the fiber to break, resulting in a costly shutdown of the fiber drawing machine. Another problem with both the collector and snagger mechanisms is that they occasionally fail to successfully transfer the fiber, again causing a costly shutdown of the fiber drawing machine. Furthermore, this tendency to miss/fail increases as the speed of the fiber increases. Given the unrelenting quest for higher drawing speeds, this tendency is clearly at odds with reliable high-speed machines.

SUMMARY

It is therefore an object of the present invention to provide a more reliable method and apparatus for transferring winding of material from one spool to another while maintaining a continuous winding operation.

It is a further object of the present invention to provide a method and apparatus for transferring winding of material between spools that does not require passing, the material over a spool flange.

It is another object of the present invention to provide a method and apparatus providing a flying (during winding) transfer of winding material between two spools that does not substantially disturb the material.

It is an object of the present invention to provide a method and apparatus for transferring winding between two spools that adheres the material to the base of the empty spool and severs the material in a single operation.

It is a still further object of the present invention to provide a method and apparatus that does not cause or require the spools to change speed during transferring of winding between spools.

Briefly, a preferred embodiment of the present invention includes an apparatus for transferring material winding between spools. The apparatus includes spindels for positioning first and second spools in a co-planar arrangement with parallel axes of rotation. With the material initially secured to the base of a first spool with tape such as adhesive tape or a similar product, a winding mechanism is energized to turn the spools. When the first spool is filled, a first sheave (grooved wheel/pulley) directs the incoming material to the second spool which is rotated at the rate of material supply. A tape applicator is then directed to apply a section of tape over the material, pressing it against the base of the second spool. A small wire is included on the base of the tape being applied. The applicator force on the wire against the material is designed to be sufficient to sever the material, separating the material on the first spool from the material being wound on the second.

An advantage of the present invention is that it avoids the need to move the material across variable diameters that cause speed changes.

A further advantage of the present invention is that it does not require moving the material over a spool flange and into a collector mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now toFIG. 1of the drawing, there is illustrated a system11including a preferred embodiment of the high speed take-up apparatus10of the present invention, shown with material12being fed into the apparatus10. The material12is drawn from a heated preform14in a draw tower16. A material buffer18provides guidance by a capstan apparatus20, and tension accommodation with a dancer mechanism22. The take-up apparatus10includes spool drive shafts24and26for turning first and second spools28and30respectively.FIG. 1shows the apparatus10in the process of winding material12onto spool28. When the spool28is nearly filled, a material positioning apparatus32, including sheaves34and36, moves to position the material12against the base38of spool30. Similarly, when the material12is attached to and winding on spool30and it is necessary to transfer to spool28, the apparatus32moves the position of the incoming material12adjacent base40of spool28. The movement of positioning apparatus32will be fully illustrated in reference to the following figures of the drawing. The take-up apparatus10includes one or two tape and cutter apparatus, illustrated symbolically as items42and43for attaching the material12to the base of the adjacent spool. In the preferred embodiment, a single tape and cutter apparatus43is used that is moved from the position as indicated inFIG. 1, to the position indicated by item number42through use of an apparatus that moves the tape and cutter apparatus from one position to the other and rotates it 180° as shown inFIG. 1.FIG. 1also shows a controller45interconnected through bus lines47,49and51to apparatus16,18and10for controlling the various operations as required.

In operation, the material12is drawn from the preform14, and is typically guided by an apparatus such as buffer18to positioning apparatus32. The material is initially attached to the base of a spool, for example, base40of spool28. The process could also begin by attachment and winding on spool30. The drawing process and winding on spool28then proceeds at a uniform rate until spool28is nearly full, at which point, the positioning apparatus32positions the material12so as to pass in proximity with the base38of empty spool30. A tape and cutter device such as43then moves to the spool base38, whereupon a length of tape with a wire preferably attached is ejected and pressed against the material12and base38. The tape secures the material to the base. The length of wire adhered to the tape lies substantially perpendicular to the direction of the material12movement, and the pressing of the wire against the material12fractures or otherwise severs it. At this point, the spool30is spinning and winding the material. The spool28is stopped, removed, and replaced with an empty spool. When spool30is nearly full, the transfer process is repeated. The positioning apparatus32moves the material adjacent the base40. The applicator-cutter as indicated by item number42as described above, moves into contact, and the tape is secured and the film severed from spool30. The apparatus ofFIG. 1is preferably designed/optimized for winding optical fiber. The present invention also includes the apparatus ofFIG. 1designed for winding any of a variety of materials, and these will be apparent to those skilled in the art.

The sequence of operations is more clearly described in reference to the illustrations ofFIGS. 2a–j.

FIG. 2ashows spool30as empty, and spool28as full, or in practice nearly full, since some time must be allowed for the transfer operation, during which the material will continually be wound on spool28until the material12is cut. The material positioning apparatus32is indicated by sheaves (grooved wheel/pulley)34and36, and the tape and cutter apparatus as items42and43. The sheaves34and36are positioned preferably approximately equidistant from the two spools30and28during the majority of the time while winding on a spool, which is a position providing a more direct path for the fiber in reaching the spool than in the more extreme positions required during the transfer of fiber winding from one spool to another. This intermediate point is indicated inFIG. 2bby the dashed line labeled “mirror line”. The mechanism/apparatus required for moving the sheaves34,36and tape and cutter apparatus42and43, and other details are not shown in order to simplify the illustration. The mechanical devices required will be described in subsequent figures of the drawing to the extent necessary for someone skilled in the art to reproduce the invention.

FIG. 2ashows spool28nearly full of winding64of material12. The system11includes apparatus (not shown) for inputting data to, the controller45sufficient,to allow the controller, programmed accordingly to calculate the speed of the fiber12. The controller also is programmed to calculate the amount of fiber wound on a spool, and when a spool is nearly full of material12, the controller45directs movement of the positioning apparatus32to a position as shown inFIG. 2bwherein the material12is in contact with the base of spool30. The controller, being programmed to know the speed of material12delivery, is also programmed to direct the rotational speed of the base38of spool30to substantially equal the speed of the material12so as to avoid material speed change during the transfer. In practice, a slight difference in the speeds may be desirable in order to maintain tension between the spools when cutter apparatus43is pushing material12against base38. The controller, for example can be programmed with the diameter of winding64when the detector66signal is received by the controller, and also with the speed of rotation of spool28. From this information and the diameter of spool30base38, the controller can be programmed to set the necessary speed of rotation of spool30. The controller also directs apparatus to move the tape and cutter apparatus43towards the spool30base38.FIG. 2cshows the tape and cutter43with the tape roller74pressing against the material12and base38of the spool30. The situation as shown inFIG. 2ccan be attained in either of two procedures as follows. The tape and cutter apparatus43can first be moved a distance from the eventual point of contact between the apparatus43and the fiber12, for example as shown in2b. When the positioning apparatus32, moving parallel with the axis of rotation of the spools30and28, brings the fiber into the position at which transfer is to take place, the tape and cutter apparatus43is moved rapidly into the cutting and taping position as shown inFIG. 2c, with the roller74pressing the fiber12against the spool38. A more preferred method of operation, however, is as follows. The wheel74of the tape and cutter apparatus43is moved into contact with the spool38prior to arrival of the fiber12. The edge of the roller74of the apparatus43is constructed with a taper/bevel so that when the fiber is pressed against the roller and spool38by the apparatus32running parallel with the axis of rotation of the spool38and apparatus43roller74, the fiber moves between the roller74and spool38. At this point, the apparatus43then proceeds with the cutting and taping operation, as will now be more fully described. At this point in time the tape and cutter43is directed by the controller to dispense a section of tape with a wire attached. The roller74then presses the tape and wire against the material12and base38. The pressure of the wire fractures/severs the material12and the tape secures the material to the base38.FIG. 2dshows the result in a view with the obscuring flange77partially cut away as indicated by the letter “A”, for more clearly showing the apparatus43and tape78and wire79. The tape78is adhering the material12to the base38and the material12is therefore now winding on the spool30. The severed material12portion80is now free of the winding process and the spool28can be stopped and unloaded, as shown inFIG. 2e. The positioning apparatus32is shown inFIG. 2emoved to the more neutral position, minimizing the stress on the material12as the winding of spool30continues. The applicator/tape and cutter43is shown in solid lines moved out of the way of positioning apparatus32. This can be accomplished in various ways, including movement to the position as illustrated. In a preferred embodiment this is accomplished by moving the applicator43in a direction parallel with the axis of rotation of the spools, taking the apparatus43out of the plane of movement of the material12. This is indicated by the arrow end82of the apparatus43shown inFIG. 2e.

The full spool28is replaced with an empty spool84, as shown inFIG. 2f. As shown inFIG. 2g, when the windings86reach a predetermined level, the controller directs the positioning apparatus32to move the material12into contact with the base88of spool84, which has been brought to the required speed to match the speed of the material. The controller then moves a second applicator42, or applicator43as explained above in reference toFIG. 1, into contact with the material12, and a tape and wire is dispensed, as illustrated inFIG. 2h, showing the fiber12and apparatus42in solid lines due to cutaway of the spool flange in area B. As shown inFIG. 2i, the material12is fractured/cut by wire91, and a tape section94adheres the material12to the base96of spool84. The spool flange is cut away for clarity of illustration in area C. The applicator42is then moved out of the path of the material12as indicated by arrow98and the positioning apparatus32moves again to a more neutral position as shown inFIG. 2j. The full spool30can then be removed and replaced with an empty spool. The process ofFIGS. 2a–jthen can be repeated until all the material12has been wound on spools.

FIG. 3is an enlargened partial view for illustration of the application of the tape and cutter material. Material12is shown in contact with the base102of a spool100. An applicator104, similar to applicators42and43ofFIGS. 1 and 2, has a roller106and a tape dispenser108. When the roller106contacts the material12, the dispenser108is directed to eject a length of tape110, which has attached a laterally oriented length of wire112, lying perpendicular to the direction of movement and length of the material12. The dispenser tape ejection mechanism is not shown, but will be understood by those skilled in the art. The dispenser108includes apparatus for ejecting a particular length of tape, and can include a tape cutting apparatus for that purpose. The tape is drawn by the roller106and friction with the moving material12and base102. The pressure,and flexibility of the roller106material is such that the roller forms around the wire and material so as to pressure and adhere the tape110against the base102. The pressure of the wire against the material12causes the material12to fracture, as indicated by line114. The incoming material12at position116is then adhered to and wound on the base102. The severed material12at118is then free to be removed along with the spool to which it is attached. Although the apparatus42and43as illustrated inFIG. 3uses a wire to sever the material12, this is a preferred embodiment that is particularly applicable when the material12is an optic fiber. The present invention also includes the apparatus42and/or43designed to cut the material12by other methods that will be apparent to those skilled in the art upon reading the above description. For example, a synchronized cutter blade (not shown) can be used for cutting a variety of types of material12.

FIG. 4is a planar view of a sketch of a production apparatus120for performing the operations of the high speed take-up apparatus10described in reference toFIGS. 1–3. A housing122is shown with first and second spools124and126installed and held in place and rotated as required by apparatus partially shown at128and130. A distributor132is shown for performing functions as described in reference to the positioning apparatus32ofFIG. 1. A sheave134is visible inFIG. 4, as well as a horizontal gantry136for moving the sheave(s)134horizontally. A vertical gantry for moving the sheaves vertically is also included, but is hidden behind the housing122and is indicated only as line138. A tape and cutter apparatus140is shown including a roller142(corresponding to roller74ofFIG. 2c) and tape dispenser144with a tape feed point146. A linear thruster148moves the tape dispenser144and roller142forward and backward as required to position the dispenser144adjacent a spool base as described above. The apparatus140includes a 180° rotation cylinder apparatus150for rotating the tape dispenser144and roller142as required to be positioned as described in reference toFIG. 1andFIGS. 2hand2i. The apparatus140is rotated by a pivot apparatus152about pivot point154in order to move the apparatus140out of the operating area of the distributor132apparatus as required.

The apparatus120ofFIG. 4also includes spool loading and unloading facility, as indicated by loading apparatus156inFIG. 5. The apparatus156has two arms158, with each arm for gripping one of two ends of a spool. Due to the planar view ofFIG. 5, only one arm is visible as the other arm on the other side of spool160is behind arm158. The apparatus has an arm drive161that is positioned equidistant from the spool positions162and164indicated by the dashed circular lines. The drive161is also the same distance to position165of a semi-circular receptor173on cart166when the cart is in a pre-determined aligned/secured position to the housing122. The, alignment of the cart to the housing122is symbolically indicated by a pin169.FIG. 5also symbolically shows two shrouds170and175for shielding the spools during the process of fiber winding. For loading and unloading, the shroud covering the accessed spool is retracted. Details concerning the construction and operation of shrouds will be apparent to those skilled in the art upon reading the present disclosure.

In operation, after the system transfers winding to an empty spool, rotation of the full spool is stopped and a notice is given that a spool is ready to be replaced. The corresponding shroud over the full spool is retracted, and an operator installs the cart166, aligning/securing it in position. The controller then directs the loading and unloading apparatus156to grasp the spool to be unloaded. This is done with extendable fingers on the arm ends171. If the full spool is at position162, for example, the arm158rotates to that position and grasps the spool. Head and tail stock for rotating the spool are disengaged, and the arm delivers the spool to the cart spool receptacle173at165. A reverse operation applies for installing an empty spool at position162. The operation is similar for loading and unloading a spool to and from location164.

The operation of the transfer of winding from one spool to another will now be described in reference to the flow chart ofFIG. 6. Transfer begins with some form of activation (block174), which can be accomplished automatically according to pre-determined criteria176, or an operator can manually initiate spool transfer at any time178. Block179indicates the manual procedure wherein an operator activates the controller, for example through a key pad, to notify the controller to direct a spool transfer. In automatic mode (block180), the controller has been pre-programmed to sense and respond to a pre-determined amount of fiber wound on a spool, and automatically direct the transfer of winding on one spool to winding on another spool. Preferably the pre-determined quantity is a prescribed length of fiber, determined by the controller from the speed and dimensions of the capstan20. The controller can alternatively determine the amount of fiber by other methods that will be understood by those skilled in the art, and these are also included in the spirit of the present invention. For example, sensors can be installed to detect the level of fiber on a spool, and the signal provided by the sensors can indicate to the controller that a spool transfer is to be activated. These sensors, for example can include a light emitter and detector.

The system11then checks to assure that an empty spool is in the transfer position (block182). In alternative embodiment, if an empty spool is not in position184, the controller45directs the system11to stop winding fiber186, and give notice that a transfer spool is required (block186). With an empty spool in position188, the controller45directs the system11to spin the empty spool through a speed matching the speed of the fiber being wound (block190). The construction of sensors, etc. required to determine fiber speed and speed of spool rotation will be understood by those skilled in the art, and therefore need not be described in the present disclosure in order to reproduce the present invention. The distributor/positioning apparatus32(FIG.1) is then directed by the controller to limit horizontal motion of the sheaves feeding the fiber being wound on a spool, to extremities between the flanges of the shortest spool of the two spools involved (block192). The controller then directs the positioning apparatus32so as to move the vertical gantry to position the sheaves feeding the fiber, to a position placing the fiber adjacent to the base of the empty spool (block194).

The controller45then directs the tape and cutter apparatus to move to the empty spool location (block196). This operation involves rotating of the apparatus140(FIG.4) around the pivot point154, rotation of the tape and cutter to the correct orientation by the rotational apparatus150, and moving the tape and cutter apparatus towards the spool base by the thruster148. The distributor horizontal gantry then passes the fiber under the tape roller (block198), and coincident with the positioning of the fiber, the thruster148presses the roller against the fiber, a tape section is dispensed by the tape apparatus and the attached wire cuts/breaks the fiber (block200). The tape at this point secures the fiber being fed by the system11, to the base of the empty spool. The tape and cutter is then retracted from the area of the empty spool (block202). The system11then proceeds with winding the fiber on the new/“empty” spool (block204). The system11then checks to determine if the transfer of fiber is complete (block206).

If transfer has not taken place207i.e. if the operations as described in reference to blocks200–204have not occurred and the fiber is still being wound on the full spool, or if the fiber is not connected to either spool, the fiber feed is stopped (block209). If the fiber has successfully been transferred to the empty spool (211), the controller then stops the rotation of the full spool (block208), and directs the distributor to move the sheaves to the normal winding position approximately equidistant from the two spools (block210). As noted in block212, a shroud is moved to cover the spool that is being wound. Similarly, a shroud is retracted from covering the full spool that at this point is not rotating, in order to allow removal of the full spool and replacement with an empty spool (block214). The controller then preferably gives a notice that a spool is ready to be replaced (block216).

The operation of checking to determine if a transfer of winding to an empty spool is complete, indicated by block206will now be described in more detail. The controller is programmed as described in reference toFIGS. 2a–2jto know which of the tape dispensers42or43has ejected tape or i.e. which of the spool positions referenced by drive shafts24or26has just had tape applied on an empty spool. The controller, as explained in reference toFIGS. 2a–2j, also knows when a spool upon which fiber is being wound reaches a “full” condition. The controller also has a separate control facility for each of the two spools. When the controller senses that a spool is “full”, it automatically adjusts the speed of the spool to achieve a pre-determined dancer22test offset, for example +31 degrees, and this state (+31) is noted by the controller. If the controller senses that a label/tape has just been applied to a spool, the controller adjusts the spool drive so that the dancer22is at an opposite pre-determined test offset, such as −31°. The controller can therefore monitor the dancer position to know if transfer has taken place by first receiving indication of a full spool by noting a dancer position of +31°, and subsequently noting a new/changed dancer position of −31°. A position of +31° (full spool) being maintained indicates that a required transfer has not occurred, and if after a pre-determined time interval the detected dancer position does not change to −31°, the winding operation is stopped, as indicated by block207. Also, if the fiber becomes disconnected from both spools, the dancer position will exceed +30° and the system is designed to detect such a position and respond by stopping the fiber feed system.

While a particular embodiment of the present invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the spirit of the present invention and its other aspects, and therefore the appended claims accomplished within the scope also has changes and modifications as follow within the true spirit and scope of the present invention.