Apparatus for controlling the drive of a laying device in a winding machine
United States Patent Nittschalk et a1.  
 APPARATUS FOR CONTROLLING THE DRIVE OF A LAYING DEVICE IN A WINDING MACHINE Assignee:  
 Inventors: Rainer Nittschalk; Rudolf Posl, both of Nurnberg; Werner Hagen, Penzendorf; Manfred Mach, Schwabach, all of Germany Siemens Aktiengesellschaft, Munich, Germany June 27, 1973 US. Cl 242/l58.4 R; 242/25 R; 242/158.2 Int. Cl B65h 54/28 Field of Search 242/l58.4 R, 158.4 A, 158,  
 242/l58.2, 25 R, 25 A References Cited UNITED STATES PATENTS 7/1963 Smith et al 242/158.4 12/1966 Sjogren 242/l58.4 X 7/1972 Henrich 242/l58.4 X  
 Primary -E.\&#39;aminerStanley N. Gilreath Attorney, Agent, or Firm-1(enyon &amp; Kenyon Reilly Carr &amp; Chapin 57 ABSTRACT A winding machine including a wire laying means, a reel on which the wire is wound, a motor for driving the wire laying means, and means for reversing the driving motor. The improvement comprises means for controlling the reversal of the wire laying means including means for sensing the ends of the reel and generating an output signal indicative thereof; means coupled to the sensing means and the motor reversing means, and responsive to the output signal generated by the sensing means, for transmitting the generated signal to the motor reversing means after a predetermined delay period; means for sensing non-uniform distribution of the wire at the ends of the reel and generating a second output signal indicative thereof; means coupled to the first output signal transmitting means and responsive to the second output signal generated for adjusting the predetermined delay period; and means coupled to the first output signal transmitting means for gradually restoring the signal delay period to the predetermined delay period.  
 5 Claims, 2 Drawing Figures APPARATUS FOR CONTROLLING THE DRIVE OF A LAYING DEVICE IN A WINDING MACHINE BACKGROUND OF THE INVENTION This invention relates to winding machines in general and more particularly to an improved manner of controlling the drive of a laying device in such a winding machine.  
  In winding materials, such as wire obtained from a wire drawing machine, on to reels or the like, a laying device is generally employed which moves back and forth across the reel to evenly distribute the material being wound as the reel rotates. At each end of the reel means are provided to cause the laying device to reverse so that it continually moves back and forth across the reel. Some devices used in initiating reversal at the end point use cams and limit switches. For example, see U.S. Pat. No. 2,845,229. With a device of this nature, a new setting is often required when reels are changed. This requirement constitutes a disadvantage particularly when using automatically operated dual reels. With devices such as this, as with any type of reversal control device, it is important that the reversing points be accurately set so that turns do not pile up at these points. Such piling up or the opposite condition i.e. a depression, are quite undesirable from a winding technology view point.  
  To avoid the disadvantages of mechanical devices, systems have been developed using sensors which operate without physical contact. These sensors may be placed on the ends ofa rod coupled to the laying device so that the sensors function without any physical contact and interact with the real flanges. Optical, pneumatic, or electrical sensors may be used for this purpose to provide the reversing signal for the laying device. Such a system is shown in German Offenlegungsschrift 2,033,284.  
  In winding systems of this nature, the speed of rotation of the reel is sometimes controlled using the motion of a feeler roller which is arranged ahead of the laying device. Typical of such a device is that shown in German Offenlegungsschrift 2,005,503. In the system illustrated therein, the reversal of the laying device is obtained in response to signals from limit switches. In addition, the signal taken off at the feeler roller is used for shifting the reversing points or to change the velocity of the laying device at the reversal points to thereby prevent piling up or thinning out of the turns as the laying device reverses. With this arrangement, the reversal command is given earlier if the turns have piled up at the end of the reel. This achieves a certain degree of compensation. However, tests have shown that a pile up can occur ahead of the end of the reel. This pile up in turn can cause, via the sensing of the feeler roller, erroneous pulses in the next reversal command andcan lead to a thinning out of the reel ends which cannot be made up.  
  Thus, there is a need for an improved control apparatus for such laying devices which avoids problems of build up and thinning out. I  
 SUMMARY OF THE INVENTION The present invention achieves these ends by providing a control arrangement for a laying device such as that described above which assures that the feeler roller will not provide erroneous information to the reversing control and thus a uniform or other predetermined distribution of winding on the reel will be obtained. To accomplish this, means are provided to cancel, over a period of time, the delay which is inserted in response to outputs of the feeler roller. This prevents the variations of the measured value, which may be caused by a change of the reversing point, from entering the controlprocess as interfering signals. In a preferred embodiment, sensors in the form of light gates which react with the reel flanges are used. The outputs of these devices are provided through delay elements, whose delay characteristics can be changed, if a predetermined value of the velocity of the feeler roller motion is exceeded. The delay inserted is then returned to a starting value over a period of time using a further timer. In this manner a decrease in the delay time caused, for example, by apile up of turns, can be cancelled out as a function of time. For example, the delay can be preset to cancel out over a one minute period.  
  A particularly advantageous drive for the laying device is obtained using an electric stepping motor. Such a motor provides an almost instantaneous reversal at any desired point without any dead time. This substantially reduces the problems associated with piling up and thinning out. In addition, stepping motor are easily adaptable to provide other desired winding geometries.  
 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevation view, partially shown in block and schematic diagram form, of a laying device according to the present invention.  
  FIG. 2 is a side view of&#39;FlG. l and showing the control elements in block diagram form.  
 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown on FIG. 1,.the material 14 to be wound which would be, for example, copper wire is fed from a wire drawing machine (not shown) with a velocity of in the order of 50 meters per second in the direction of arrow 24 to be wound in turns 9 on a reel 5. Reel 5 comprises a central cylindrical core 6 attached to end flanges 7 and 8 and is mounted for rotation in conventional fashion and driven by a motor 10. The wire 14 is brought over a feeler roller 15 to the laying device 1 which guides it back and forth in the direction of arrow 26 across the core 6 of reel 5. At each of the flanges 7 and 8 the laying device 1 must reverse its direction. Laying device 1 will be, for example, a pulley-like member threaded on the inside and driven by a spindle 2 having matching threads so that the rotation of the spindle 2 will cause motion of the laying device 1. Spindle 2 is driven by a motor 3 which is controlled by a control device 4.-Control device 4 causes motor 3 to rotate in either a clockwise or counterclockwise direction to thereby cause the laying device 1 to move in one of the two direction indicated by arrow 26. The position of the feeler roller 15 is converted by a rotary potentiometer 16 into an electrical quantity in a well known manner. The motor 10, driving the reel 5 is controlled by control means 25 in a manner such that the winding velocity of the wire remains constant. That is, with increasing diameter of the winding of the speed of rotation is reduced for example from 8,000 RPM when the reel is empty to 4,000 RPM with a fully wind reel.  
 Such a drive system is disclosed in the above referenced German offenlegungsschrift 2,005,503. A tachometer 11 which will provide an electrical signal pro- 3 portionalto the speed of the motor at its output is also shown.  
  To determine the proper point of reversal, there is attached to each side of the laying device 1a light gates 12 and 13 respectively. Light gate 13 comprises a transmitter 131&#39; and a receiver 132. Similarly light gate 12 comprises a transmitter 121 and a receiver 122. Transmitters l3l and l2l will comprise a light source which willdi rect a beam of light toward their respective receivers 132&#39;and 122. The receivers 132 and 122 may by any conventional light detector. When between the flanges, the light emitted by the transmitters will be detected by the receivers and each will provide an output signal. However, when either end of the reel is reached 7 one of the light paths will be broken by a reel flange and the signal will disappear. This may then be detected-to initiate a reversal as will be described below. For example, when moving to the left, the light gate 13 will have its light path interrupted by the reel flange 8 causing a reversal and motion to the right. When the laying device 1 gets all the way to the right hand side, the light path of the light gate 12 will be broken by the reel flange 7 causing a reversal of direction and motion to the left.  
  The control system for the laying device of the present invention is illustrated in more detail by the block diagram of FlG. 2. The outputs of the receivers 122 and 132 &#39;are respectively provided to- AND gates 23c and 23d. Gate 230 has an enabling signal designated L from a flip flop 23a indicating motion in the left hand direction&#39; and gate 23d an enabling signal designated R from a flip flop 23b indicating motion in the right hand direction. Thus, the light gate 12 and its associated receiver 122 is enabled only when moving toward the right. Similarly, the light gate 13 and its receiver 132 are only enabled&#39;when moving to the left. The signal from transmitter 132 provides a set input to flip flop 23b and a reset input to flip flop 23a. Similarly the signal from transmitter 122 is used to set flip flop 23a and reset flip flop 23b. Thus when the laying device moves all the way&#39;left flip flop 23b is set to enable the gate 23d associated with transmitter 122 for detecting the end of motion to the right. The opposite occurs when the laying device moves all the way left. The signal provided at the outputof transmitter 132 is provided through the gate 23c and a delay means 21, to be described below, to the control means 4. In like manner, the output of the receiver 122 is provided through gate 23d and a time delay 22 to control means 4. Control means 4 will, for example, comprise a bidirectional latching relay 4a having the respective outputs of delays 21 and 22 as its two inputsfthe contact of relay 4a switching in response thereto to reverse the direction of the motor 3 of FIG. 1. Delay means 21 and 22 can comprise conventional resistor capacitor delay circuits which include respectively variable resistors 27 and 28 each having an associated capacitor to ground at its output and which resistors are controlled in a manner to be describedbelow. Thus, by setting of the variable resistors or potentiometers 27 and 28 it is possible to vary the amount&#39;of delay between the time when one of the receivers ,122 and 132 first generatesa reversing signal and the time when the reversing occurs at motor 3. In general terms, the delay time is initially adjusted based on the dead time of the reversing drive and, as will be described below, also on the value S as output by the potentiometer l6.  
  The output&#39;of the potentiometer 16, providing an electrical signal which is proportional to the position S of the feeler roller 15, is provided to a differentiator 17 which comprises a conventional operational amplifier 17a having input and feed back circuits arranged to provide differentiation. This differentiation will result in the value ds/dt or the velocity of pivotal motion of the feeler roller 15. This value of velocity is then used as the input to a control stage 18. Its value is sensed and, if that value exceeds a predetermined level, it is used to control the time delay of the delay means 21 and 22 by adjusting the value of the resistances 27 and.  
 28. As shown, the control stage 18 includes monostable multivibrator 18a arranged to trigger when the output of differentiator 17 exceeds a preset value. The output of multivibrator 18a is coupled&#39;to a motor which positions the potentiometers 27 and 28. Similarly, control of the resistances 27 and 28 may be done wholly electronically, for example, by converting the sampled voltage in a analog to digital converter and using the digital output to switch in appropriate resistances.  
  In operation, when a build up occurs on the reel 5, it is detected by the feeler roller 15. A build up will cause the feeler roller to be jerked down. This change in S will be transmitted by the potentiometer l6 and after differentiation will result as an output from differentiator 17 indicating a significant velocity which exceeds the preset level. In response to this multivibrator 18a will provide a voltage output of a polarity to drive motor 18b as to adjust the potentiometers 27 or 28 to provide a shorter delay time so that reversal occurs before the wire gets all the way up to the end where the pile up occurred. This will result in the rest of the winding being brought up to where it is even with the buildup portion near the edge. However, if this delay is not changed, the result will be a thinning out near the edges. That is reversal occurs early so that wire is not wound near the flanges. Thus, it is essential that over a time period, during which the remainder of the winding has time to build up, the delay again be lengthened so as to continue winding wire all the way to the flanges without a thinning out. To accomplish this, a second multivibrator 19a, a gate 19b and resistor 18c are provided. The multivibrator will trigger at the same time as multivibrator 180. This output will be blocked initially at gate 19b by the output of multivibrator 18a. At the end of the signal from multivibrator 18a the output of gate 19b will provide through resistor 18c a signal of opposite polarity to slowly return the motor 18b to its original position. This results in a fast correction with a slow cancelation thereof. Multivibrator 18a will output a pulse shorter than that of multivibrator 19a so that the required operation occurs properly. The end result of operation in this manner is that peaks are detected and removed without the danger of thinning out portions of the. winding.  
  The operation of this system will now be summarized. Primary control of the laying of the wire or the like on the reel 5 is controlled through the light gates 12 and 13 which will cause a reversal as the ends of the reels are reached. The use of light gates permits using reels of different size without any modification. Based on the known characteristics of the device a predetermined time delay is determined and set into the time delay means 21 and 22 insuch a manner as to compensate for the dead time of this system in reversing. However, since this cannot be done with complete accuracy, the  
 velocity of the feeler roller over the laying device 1 is obtained and used to shorten the delay time when a build up is sensed near the ends. This will result in the winding not reaching all the way to the ends of the reel. If allowed to continue, a valley would develop which would not be sensed since the winding would never reach the point of the valley and thus the feeler roller would not respond thereto. To avoid this problem, additional means are provided which gradually restore the time delay of the delay means 21 and 22 to their normal delay length thus resulting in the winding gradually moving out to the edges and the peak being eliminated without the danger of having valleys at the end of the reels.  
  Various modifications may be made to the present invention. For example, instead of using a feeler roller, a tachometer roller or a tension measuring device may also be used. A peak in the winding also causes an increase in the wire velocity which would be sensed by the tachometer roller. Due to the mass inertia of the deflection roller in a tension measuring device, a peak will cause an increase in wire tension which can also be sensed. These and other modifications may be made without departing from the spirit of the invention which is intended to be limited solely by the appended claims.  
  What is to be claimed is: 1. In a winding machine including a wire laying means, a reel on which the wire is wound, a motor for driving the wire laying means, and means for reversing the driving motor, means for controlling the reversal of the wire laying means, comprising:  
 means for sensing the ends of said reel and generating a first output signal indicative thereof;  
 means. coupled to said sensing means and said motor reversing means, and responsive to said output signal, for transmitting said signal to said motor reversing means after a predetermined delay period;  
 means for sensing non-uniform distribution of the wire at the ends of said reel and generating a second output signal indicative thereof;  
 means, coupled to said first output signal transmitting means and responsive to said second output signal, for adjusting said predetermined delay period; and  
 means, coupled to said first output signal transmitting means, for gradually restoring the signal delay period to said predetermined delay period.  
  2. The invention according to claim 1, wherein said reel comprises a central core and two end flanges, and wherein said means for sensing the ends of said reel comprise light gates arranged to intersect the flanges of said reel.  
  3. The invention according to claim 2 wherein a pivotable roller is installed ahead of the laying device in engagement with the wire, and said means for sensing non-uniform wire distribution comprises means for sensing the velocity of pivotal motion of said feeler roller and means for adjusting said predetermined delay period when said feeler roller velocity exceeds a predetermined value.  
  4. The invention according to claim 1 wherein said driving motor comprises an electric stepping motor.  
  5. A method of controlling the reversal of direction of a wire laying means driven by a motor, which winds the wire on a reel in a winding machine, comprising the steps of:  
 moving the wire laying means to distribute wire on the reel;  
 sensing the point at which the ends of the reel are reached by said wire laying means;  
 reversing the direction of the wire laying means a predetermined delay time after said reel ends are sensed;  
 sensing the uniformity of distribution of the wire wound on the reel;  
 adjusting said delay time when non-uniform wire distribution on said reel is sensed; and  
 gradually restoring said delay time to said predetermined delay time.  
  UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 7 1 7 DATED April 8 1975 &#39;NVENT0R(5 1 Rainer Nittschalk et al It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:  
 In column 4, llne 8, change &#34;feeler roller 15.&#34; to read --feeler roller 15 about its axis Signed and Scaled this seventh D3) Of October 1975 [SEAL] Attest:  
 . RUTH c. MASON c. MARSHALL DANN Arresting Officer Commissioner uj&#39;Parents and Trademarks