Abstract:
In one aspect, a method of correcting a loosely wound supply roll to be used with a label applying machine is described. The method includes providing a supply roll having a material web wound thereon, the supply roll mounted on a supply roll spindle such that the material web is aligned with an intake of a labeling mechanism on the label applying machine. The method further includes mounting a moveable web guide to apply pressure to the material web being supplied to the labeling mechanism, wherein the web guide includes an encoder. The method further includes determining the tension of the material web wound around the supply roll using the movable web guide and the encoder. Further still, the method includes adjusting the tension of the material web wound around the supply roll if the material web is determined to be too loosely wound about the supply roll to provide adequate tension to the web as the web leaves the supply roll.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates generally to label application machinery, and more specifically to systems and methods of testing for a loosely wound supply roll and correcting a loosely wound supply roll. 
         [0002]    Label rolls produced by manufactures can be wound very loosely anywhere within the roll. This looseness prevents the label application machinery from either calculating an accurate starting diameter of a label roll, or providing adequate web tension to the label roll. Inadequate web tension of the label roll can inhibit control of the label roll. When a label application machine inaccurately calculates the starting diameter of a label roll, or when inadequate web tension is present, the label application machine shuts down. This causes excessive and unacceptable downtime and waste in the form of unusable rolls of material. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    In one aspect, a method of correcting a loosely wound supply roll to be used with a label applying machine is provided. The method includes providing a supply roll having a material web wound thereon, the supply roll mounted on a supply roll spindle such that the material web is aligned with an intake of a labeling mechanism on the label applying machine. The method further includes mounting a moveable web guide to apply pressure to the material web being supplied to the labeling mechanism, wherein the web guide includes an encoder. The method further includes determining the tension of the material web wound around the supply roll using the movable web guide and the encoder. Further still, the method includes adjusting the tension of the material web wound around the supply roll if the material web is determined to be too loosely wound about the supply roll to provide adequate tension to the web as the web leaves the supply roll. 
         [0004]    In another aspect, an apparatus for correcting a loosely wound supply roll to be used with a label applying machine is provided. The apparatus includes a supply roll mounted on a supply roll spindle, the supply roll having a material web wound thereon. The apparatus also includes a motor mechanically coupled to the supply roll spindle. The apparatus further includes an angular feedback device including an encoder, wherein the angular feedback device is configured to measure a displacement of a dancer roller. The apparatus further includes a processor configured to test the tension of the material web wound around the supply roll using the dancer roller and the angular feedback device, and the processor configured to adjust the tension of the material web wound around the supply roll if the material web is determined to be too loosely wound around the supply roll. 
         [0005]    In yet another aspect, a computer program embodied on a computer readable medium for testing and correcting a supply roll of material is provided. The program includes at least one code segment that prompts a user to initiate a test method, at least one code segment that provides a motor with a direction and amount in which to rotate, at least one code segment that determines a tension of a material web wound around the supply roll, and at least one code segment that prompts a start of a tension adjusting computer code if the material web is determined to be too loosely wound around the supply roll. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a schematic diagram of a label applying machine having a web guide roller near a bottom limit in accordance with one embodiment of the invention. 
           [0007]      FIG. 2  is a schematic diagram of the label applying machine shown in  FIG. 1  having the web guide roller near mid-travel in accordance with one embodiment of the invention. 
           [0008]      FIG. 3  is a schematic diagram of the label applying machine shown in  FIG. 1  having the web guide roller near a top limit in accordance with one embodiment of the invention. 
           [0009]      FIG. 4  is an exemplary embodiment of a flow chart illustrating a method of testing the windings of a supply roll. 
           [0010]      FIG. 5  is an exemplary embodiment of a flow chart illustrating a method of correcting the windings of a supply roll. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    A method and an apparatus for determining whether a material web is loosely wound around a supply roll are described herein. In addition, a method and an apparatus for tightening the material web around the supply roll are described herein. The present invention is described below in reference to its application in connection with and operation of an apparatus for providing a material web. The web includes a continuous web of printed or non-printed labels coupled in a serial configuration from a supply roll located upon a spindle supported by a support stand to a label applying mechanism. It will be apparent to those skilled in the art and guided by the teachings herein provided that the invention is likewise applicable to any apparatus and/or method for feeding suitable web materials. 
         [0012]    Referring now to the figures,  FIG. 1  is a schematic illustration of a label applying machine  10  having a web guide  12 . More specifically,  FIG. 1  is an illustration of machine  10  configured to guide a material web  14  from a supply roll  16  to a label applying mechanism (not shown). Supply roll  16  is mounted on a supply roll spindle  18 . Material web  14  is wound around supply roll  16 . Material web  14  is threaded around a first idler roller  18 , web guide roller  12 , and a second idler roller  22  before reaching the label applying mechanism. Web guide roller  12 , also known as a dancer roller or supply roll dancer web guide roller, is connected to an arm  24  that is connected to a pivot pin  26  and an angular feedback device (not shown). A pressure supplying device  28 , for example, an air cylinder, is attached to web guide arm  24  at a first end and is fixed to machine  10  at second end  30 . Pressure supply device  28  exerts a force on web guide arm  24 , which exerts a force on material web  14  to maintain a desired level of web tension at supply roll spindle  18 . Web guide arm  24  moves between an upper web guide motion limit  32  and a lower web guide motion limit  34 . 
         [0013]      FIG. 2  is a schematic diagram of label applying machine  10  having web guide  12  located near a mid-travel position. Web guide  12 , and therefore web guide arm  24 , are positioned approximately midway between upper web guide motion limit  32  and lower web guide motion limit  34 . Supply roll spindle  18  is provided with instructions from a motion controller/processor  36  to rotate in a direction that should pull web material back onto supply roll  16 . For the embodiment of  FIG. 2 , a clockwise rotation pulls web material back onto supply roll  16 . Under normal operating conditions, and with a tightly wound label roll, web guide  12  changes position in response to the clockwise rotation of spindle  18 . If material web  14  is wound too loosely around supply roll  16 , rotation of supply roll spindle  18  in a direction that should pull web material back onto supply roll  16  will not cause a change in the position of web guide  12 . Alternatively, if material web  14  is wound too loosely around supply roll  16 , rotation of supply roll spindle  18  in a direction that should pull web material back onto supply roll  16  will cause a change in the position of web guide  12  to occur at a lower rate than expected. 
         [0014]    Supply roll spindle  18  is connected to a servo or stepper motor (not shown) with a position feedback device (not shown). The motor and feedback device are connected to motion controller/processor  36 . Controller  36  is a device capable of controlling the movement and position of the motor. Controller  36  is programmable. As controller  36  instructs stepper motor (not shown) to rotate supply roll spindle  18  a fixed amount, angular feedback device and encoder (not shown) provides controller  36  with information on the movement of web guide  12 . 
         [0015]      FIG. 3  is a schematic diagram of label applying machine  10  having web guide  12  located near an upper-travel position. Web guide  12 , and therefore web guide arm  24 , are positioned near upper web guide motion limit  32 . 
         [0016]      FIG. 4  is an exemplary embodiment of a flow chart illustrating a method of testing the windings of a supply roll. Prior to beginning test method  50 , supply roll  16  and material web  14  are configured to be fed to the label applying mechanism. Test method  50  enables controller  36  to determine the amount of slack within supply roll  16  to determine whether supply roll  16  is sufficiently wound to provide a suitable material web tension for proper operation of the label applying mechanism. Test method  50  typically begins upon a command from controller  36  to the motor (not shown) mechanically coupled to supply roll spindle  18 . This command from controller  36  instructs the motor to rotate  54  supply roll spindle  18 , and therefore supply roll  16 , a first fixed amount in a direction that pulls material web  14  onto supply roll  16 . In one embodiment, prior to rotating  54  spindle  18 , a measurement of the diameter of supply roll  16  is performed, for example, by an ultrasonic sensor. 
         [0017]    Rotating  54  spindle  18  in a direction that pulls material web  14  onto supply roll  16  has the effect of applying a force to web guide  12 , causing web guide  12  and arm  24  to move from a lower web guide motion limit  34  toward upper web guide motion limit  32 . Calculating a threshold web guide displacement  56  consists of configuring controller  36  to calculate a threshold web guide displacement, corresponding to a tightly wound supply roll, within a range of supply roll diameters, for a given supply roll spindle rotation  54 . Measuring an actual web guide displacement  58  includes configuring the angular feedback device (not shown), attached to arm  24 , to provide controller  36  with an actual displacement of web guide  12 . 
         [0018]    Test method  50  includes programming controller  36  to compare  60  actual web guide displacement  58  to calculated threshold web guide displacement  56 . If actual web guide displacement  58  is equal to or greater than calculated threshold web guide displacement  56 , and web guide  12  has moved past a mid-travel position  62  (see  FIG. 2  for approximate location of a mid-travel position), the supply roll is considered to be acceptable and the label applying machine begins a normal startup procedure  64 . 
         [0019]    If actual web guide displacement  58  is equal to or greater than calculated threshold web guide displacement  56 , and web guide  12  has not moved past a mid-travel position  62  (see  FIG. 2  for approximate location of a mid-travel position), controller  36  re-starts test method  50 . 
         [0020]    If actual web guide displacement  58  is less than calculated threshold web guide displacement  56 , this constitutes a first iteration of a failed test. Controller  36  counts the number of failed tests  66 . Controller  36  is provided with a pre-set upper limit of failed test iterations by a user. If the pre-set upper limit of failed test iterations is not reached  68 , controller  36  is configured to re-start test method  50 . If the pre-set upper limit of failed test iterations is reached  68 , controller  36  initiates a correction method  80 . 
         [0021]      FIG. 5  is an exemplary embodiment of a flow chart illustrating correction method  80  to correct the windings of a supply roll, such as supply roll  16  shown in  FIG. 1 . Correction method  80  reduces the level of slack within supply roll  16  after test method  50  determines correction is necessary and that supply roll  16  is not adequately wound for proper operation of the labeling machine. Correction method  80  typically begins  82  upon a command from controller  36  after test method  50  reaches a set number of failed test iterations  68 . This command from controller  36  instructs the motor to continuously rotate  84  supply roll spindle  18 , and therefore supply roll  16 , in a direction that pulls material web  14  onto supply roll  16 . Controller  36  also starts a timer, counting toward a set time limit for correction method  80 . In one embodiment, prior to rotating  84  spindle  18 , a measurement of the diameter of supply roll  16  is taken, for example, by an ultrasonic sensor. 
         [0022]    Rotating  84  spindle  18  in a direction that pulls material web  14  onto supply roll  16  has the effect of applying a force to web guide  12 , causing web guide  12  and arm  24  to move from lower web guide motion limit  34  toward upper web guide motion limit  32 . The angular feedback device (not shown) attached to arm  24  provides controller  36  with data indicating the displacement of web guide  12 . Once web guide  12  reaches a position  86  near upper web guide motion limit  32  (see  FIG. 3 ), controller  36  reverses the direction of rotation of spindle  18  until web guide  12  nears the lower travel limit  34 . Test method  50  is then restarted. 
         [0023]    If web guide  12  has not reached a position  86  near upper web guide motion limit  32 , controller  36  continues to count toward a time limit. This time limit is provided to controller  36  by a user. If this time limit is reached  90 , controller  36  indicates that supply roll  16  is unsuitable for use and is rejected  92 . Setting time limit  90  prevents the labeling machine from being indefinitely tied up in test method  50  and correction method  80 . 
         [0024]    In one embodiment, a computer program is provided to controller  36 . The program is embodied on a computer readable medium and utilizes a Structured Query Language (SQL) with a client user interface front-end for administration and a web interface for standard user input and reports. In an example embodiment, the system is web enabled and is run on a business-entity intranet. In another embodiment, the system is fully accessed by individuals having an authorized access outside the firewall of the business-entity through the Internet. In a further example embodiment, the system is run in a Windows® NT environment (Windows is a registered trademark of Microsoft Corporation, Redmond, Wash.). The application is flexible and designed to run in various different environments without compromising any major functionality. 
         [0025]    The systems and processes are not limited to the specific embodiments described herein. In addition, components of each system and each process can be practiced independent and separate from other components and processes described herein. Each component and process also can be used in combination with other assembly packages and processes. 
         [0026]    The computer program embodied on a computer readable medium for testing and correcting supply roll  16  prompts a user to initiate test method  50 . The computer program includes computer code that corresponds to the steps of test method  50  including, providing the motor with a direction and amount in which to rotate  54 , calculating a threshold web guide movement corresponding to the provided motor rotation  56 , comparing the calculated threshold web guide movement to an actual web guide movement  60  provided to the computer program by an encoder  58 , monitoring the actual displacement of the web guide  62 , counting iterations of fixed supply roll rotations  68 , and either beginning a normal label applying machine setup procedure  64 , or prompting a start of correction method  80  if material web  14  is determined to be too loosely wound around supply roll  16 . 
         [0027]    The computer program embodied on a computer readable medium for testing and correcting supply roll  16  also includes computer code that corresponds to the steps of correction method  80 . These steps include instructing the motor to continuously rotate the spindle  84 , monitoring the web guide movement  86 , and maintaining a count  90  of the length of correction method  80 . The computer program is provided with an upper time limit for correction by a user. The computer program reverts back to the computer code corresponding to test method  50  when web guide  12  reaches an upper limit of web guide movement. The computer program provides a user with an indication that supply roll  16  is rejected  92  if the upper time limit for correction passes prior to web guide  12  reaching an upper limit of web guide movement  86 . 
         [0028]    While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.