Abstract:
A system and method of monitoring a wire feed speed using a wire feed speed monitoring system and a computer peripheral pointing device having a motion sensor which senses motion of a wire passing by the motion sensor.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    Devices, systems, and methods consistent with the invention relate to measuring wire feed speed. 
         [0003]    2. Description of the Related Art 
         [0004]    When welding it is often desirable to measure and monitor the wire feed speed of the welding wire (or electrode) as it is being fed to the welding operation. Wire feed speed measurements can be utilized during a welding operation to determine proper operation of a wire feeder or other aspect of the welding operation. Further, with wire feed speed measurements taken during a welding operation, adjustments can be made to the welding operation based on the measured information regarding the wire feed speed. Variations in wire feed speed can often be caused by a worn liner, slipping wire drive rolls or a worn contact tip, as well as other problems. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    An exemplary embodiment of the present invention is a wire feed speed monitoring apparatus, comprising a computer peripheral pointing device having a motion sensor and a wire feed speed monitoring system to receive motion signals from the computer peripheral pointing device. The computer peripheral pointing device uses the motion sensor to monitor a feed speed and a motion of a wire and provides data related to the feed speed and motion to the wire feed speed monitoring system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The above and/or other aspects of the invention will be more apparent by describing in detail exemplary embodiments of the invention with reference to the accompanying drawings, in which: 
           [0007]      FIG. 1  illustrates a diagrammatical representation of a welding system incorporating an exemplary embodiment of a wire feed speed measurement system of the present invention; 
           [0008]      FIG. 2  illustrates a diagrammatical representation of a further welding system containing another exemplary embodiment of a wire feed speed measurement system of the present invention; 
           [0009]      FIGS. 3A-3C  illustrate diagrammatical representations of exemplary embodiments of the present invention; 
           [0010]      FIG. 4  illustrates a diagrammatical representation of a further exemplary embodiment of the present invention; and 
           [0011]      FIG. 5  illustrates a diagrammatical representation of an additional exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0012]    Exemplary embodiments of the invention will now be described below by reference to the attached Figures. The described exemplary embodiments are intended to assist the understanding of the invention, and are not intended to limit the scope of the invention in any way. Like reference numerals refer to like elements throughout. 
         [0013]      FIG. 1  is a representative diagrammatical representation of a welding system  100  incorporating an exemplary embodiment of the wire feed speed measurement system of the present invention. Specifically the welding system  100  contains a welding power supply  101  of a known type which is used to provide a welding waveform to a welding torch  105 . The power supply  101  is also coupled to a wire feeder  103  which feeds a welding wire W from a wire source  109  through drive rolls  107  to the welding torch  105 . Such a system is generally known in the welding industry and will not be discussed in detail herein. 
         [0014]    Also included in the system  100  is a wire feed speed measurement device  113  which is coupled to a wire feed speed monitoring system  111 . In exemplary embodiments of the present invention the wire feed speed measurement device  113  is a computer peripheral pointing system, which in some embodiments can be an “off-the-shelf” computer “mouse”. The device  113  can be of either a contact type or a non-contact type peripheral device. The contact type device often uses a roller ball at the bottom of the device  113 , while the non-contact type often uses an LED light with optical sensors. As is known, computer pointing system devices (e.g., computer mouse) contain a motion sensor which is capable of tracking movement in both an X and Y direction and communicates this movement to processors so that the movement data can be used as desired. Because the structure, function and operation of computer peripheral pointing systems (computer mouse) is well known by those in the computer industry and need not be discussed or described in detail herein. 
         [0015]    The use of a computer peripheral pointing system as the wire feed speed measurement device  113  is advantageous over known wire feed speed measurement systems. Specifically, some wire feed speed measurement systems are extremely expensive or require significant contact with the welding wire W such that the devices squeeze the wire W and can deform it. Further, current wire feed speed measurement devices can only measure the linear movement of the wire. However, it is often important to also determine if the wire W is rotating, which can be detrimental to a proper welding operation. The use of a computer peripheral pointing system as the sensor eliminates each of these drawbacks as they are low cost items and either requires no contact with the wire or minimal contact to track the movement of the wire. 
         [0016]    In operation the device  113  is positioned such that its motion sensor, whether it be a contact or non-contact type can accurately sense the movement of the wire. In further embodiments, the device  113  is modified to include a wire guide to guide the wire W under the sensor for accurate detection of wire feed speed. During operation the linear movement of the wire is sensed by the device  113  and the movement data is transmitted, wirelessly or via a physical connection, to the wire feed speed monitor system  111 . The wire feed speed monitor system  111  can be any type of computer system capable of receiving data from the device  113  and is specially programmed to interpret the movement signals from the device  113  in to wire feed speed measurements of the wire W during operation. In some exemplary embodiments of the present invention an optical computer peripheral pointing device  113  is employed which has a sampling rate of 1,500 samples per second. Such a sampling rate allows the wire feed speed measurement system to detect variations in the wire feed speed wire traveling up to 1,200 inches per minute. This is significantly improved over existing wire feed speed detection systems. 
         [0017]    Further, in addition to interpreting the linear movement of the wire W, the wire feed speed monitor system  111  can also have programming to monitor rotation of the wire W as it is fed to the torch  105 . This would be interpreted by sensed movement in the Y direction by the device  113 . This information can be utilized by the system to track rotation in the wire W which could be an indication of a problem in the wire feeding system or the wire. 
         [0018]    The wire feed speed monitoring system  111  can be any type of computer system which is programmable such that it can be programmed to interpret the data and information from the device  113  into wire feed speed. The system  111  can also include memory devices to store wire feeding data and information and may also include a display device to visually display information related to the wire feeding operation, including: wire feed speed, fluctuations or variations in wire feed speed, wire rotation or other desired variables. 
         [0019]    The device  113  can be positioned at any positioning along the wire feeding system. However, in an exemplary embodiment of the present invention the device  113  is positioned downstream of the wire feeder rollers  107 . In a further exemplary embodiment of the present invention, multiple devices  113  are employed. In this embodiment the wire feed speed at multiple locations in the wire feeding system can be monitored for variations. For example, a first device  113  can be positioned upstream of the wire feeder  103 , prior to the wire W impacted the rollers  107 , and a second wire feed device can be positioned downstream of the rollers  107 . In this configuration, the wire feed speed monitoring system  111  can determine if any speed differential exists between the detected wire feed speeds between the first and second devices  113 . This information can be utilized to determine the operation of the wire feeder  103  and/or the rollers  107 . For example, if a differential, over a threshold differential, is detected in the wire feed speeds from the first and second devices the wire feed speed monitoring system  111  can issue a warning and/or stop the wire feeder  103  or the power supply  101 . 
         [0020]      FIG. 2  depicts another exemplary welding system  200 . However, in this welding system the wire feed speed monitoring system  201  is incorporated into the control electronics of the power supply  101 . Further, the device  113  communicates with the wire feed speed monitoring system  201  wirelessly. In an alternative embodiment, the device  113  can be hardwired to the system  201  and/or the power supply  101 . In this embodiment the wire feed speed monitoring system  201  can display the detected wire feed speed on the power supply  101  and/or can assist in the control of the wire feed speed. For example, in some exemplary embodiments if the detected wire feed speed falls below or exceeds a threshold the wire feed speed control system  201  can issue an emergency stop signal to the power supply  101  and or the wire feeder  103  to stop the welding and feeding operation. Alternatively or additionally, the wire feed speed monitor system  201  can be used to control the wire feeder  103  based on the measured wire feed speed from the device  113 . For example, if the detected wire feed speed of the wire W is outside of an acceptable operating range the wire feed speed monitoring system  201  instructs the power supply  101  and/or the wire feeder  103  to either increase or decrease the wire feed speed so that the wire feed speed is maintained within the desired operational range to continue a proper welding operation. 
         [0021]      FIGS. 3A to 3C  depict various embodiments of the wire feed speed measuring device  301 / 305  of the present invention. As depicted the device  301 / 305  is a computer peripheral pointing device, a computer mouse. In  FIG. 3A  the device  301  is a contact type device using a ball  303 , while in  FIGS. 3B and 3C  the device  305  is a non-contact device which, for example, uses an LED and optical sensors to detect movement. As shown in  FIG. 3C  the device  305  can be quipped with a wire guide  309 , which can be affixed by any known means, to ensure that the wire W is positioned under the motion sensor  307  of the device  305 . The guide  309  may also include a friction reducer  311  which reduces friction between the wire W and the guide  309  and to reduce or eliminate scratches in the wire W. 
         [0022]    The device  301 / 305  shown in  FIGS. 3A-3C  is shown as typical off-the-shelf computer peripheral pointing devices. However, in other exemplary embodiments of the present invention, it is not necessary that the outer shell or housing the pointing devices be maintained for operation of the device  301 / 305  in embodiments of the present invention. 
         [0023]    Turning now to  FIG. 4 , another exemplary embodiment  400  of the present invention is depicted which is capable of monitoring and detecting cast or twisting in the welding wire W. Specifically, it is known that welding wires W can often have a cast, twist or curvature in the wire which may be a function of its winding and/or packaging process. This anomaly in the wire can affect the positioning of the wire W during the welding process. For example, if a straight line weld is desired a twist or cast in the wire W can result in a non-straight weld bead because the wire W will move as it exits the torch  105 . That is, a significant cast or twist in the wire W can cause the weld bead to move to either side of a desired straight path. In welding operations which require high precision this can be problematic. The system  400  shown in  FIG. 4  is capable of minimizing the effects if certain twists and cast in the wire W during welding. 
         [0024]    Specifically, in this embodiment the wire feed speed monitoring system  111  communicates with a torch positioning system  401 . The torch positioning system  401  is employed and configured to change the positioning of the welding torch  105  during the welding process. The torch positioning system  401  can use motors, gears or other mechanisms (not shown) to change the positioning of the torch  105 . Such mechanisms are known in the automatic and robotic welding industry and will not be described in detail herein. 
         [0025]    During welding the device  113  is positioned a distance D from the exit of the torch tip in the welding torch  105  such that the distance D is known. The distance D can be predetermined and programmed into the wire feed speed monitoring system  111 . As described above, the device  113  and monitoring system  111  can detect the wire feed speed and any rotation in the wire W as it is being fed. During welding, if a twist is detected in the wire W by the device  113  and monitoring system  111  the monitoring determines whether or not the torch  105  needs to be moved to accommodate for the detected twist. That is, in an exemplary embodiment if a twist in the wire is detected the monitoring system  111  then communicates with the torch positioning system  401  to adjust the positioning of the torch  105  to ensure that the weld bead is maintained in its desired path even though a twist or anomaly exists in the wire W. The monitoring system  111  bases the communications with the torch positioning system  401  on the distance D and the detected wire feed speed and detected twist in the wire W. Specifically, the monitoring system  111  determines the length of time the detected twist will take to travel the distance D at the detected wire feed speed and instructs the torch positioning system  401  to move the torch  105  the appropriate distance at the appropriate time. That is, at the time the detected twist will reach the exit of the welding torch  105 . 
         [0026]    In another exemplary embodiment of the present invention, the monitoring system  111  only communicates with the torch positioning system  401  when the twist or anomaly in the wire is over a threshold amount. Thus, the torch  105  will not be moved if the detected twist in the wire W is not determined to be significant or would render the weld bead unacceptable. However, if the twist or anomaly is determined to be over the threshold amount then the monitor system  111  communicates with the positioning system  1401  to adjust the positioning of the torch  105  appropriately. 
         [0027]    It is noted that although the monitoring system  111  and positioning system  401  are shown in  FIG. 4  as separate components, in other exemplary embodiments these components can be integral into a single controller system. The present invention is not limited in this regard. 
         [0028]    In a further exemplary embodiment, the system  400  shown in  FIG. 4  controls the travel speed of the torch  105  based on the detected wire feed speed of the wire W. Specifically, it may be desirable to maintain a constant amount of welding wire W over a specified length of the weld to be created. If the wire feed speed of the wire W changes during welding this may result in either too much or too little of the wire W being delivered to the weld for a specified length of weld. Therefore, similar to the discussion above the monitoring system  111  and the positioning system  401  are used to control the travel speed of the torch  105  based on the detected wire feed speed. So, if the detected wire feed speed increases then the positioning system  401  will increase the travel speed of the torch  105  to maintain a constant deposition rate. Similarly, if the wire feed speed decreases the positioning system will slow the travel speed of the torch  105  so as to maintain the desired deposition rate. Of course, in some exemplary embodiments of the present invention, changes in the travel speed of the torch  105  will only incur if the detected wire feed speed is higher than or lower than a threshold. Therefore, so long as the wire feed speed is within an acceptable operational range there will be no changes in the travel speed of the torch  105 . 
         [0029]    Another aspect of the present invention is depicted in  FIG. 5 . In this embodiment, aspects of the invention are employed during the wiring drawing/packaging process. In the exemplary embodiment shown in  FIG. 5  a wire winding system  500  is shown which is used to wind welding wire W into a welding wire container  507 , which is often a bulk welding wire container. The system  500  contains a wire winding machine  501  which has a series of shaping rollers  503 , which are used to shape the wire W, a capstan  505  and a laying head  507 . During winding, the wire W is pulled by the capstan  505  and pushed down through the laying head  509  into the container to create a spool or coil or weld wire  511 . The general construction and operation of wire winding machines is known and will not be discussed in detail herein. However, it is noted that the present invention is not limited to the specific winding machine  501  described herein and can be used on any wire winding or wire drawing machines, which draw the wire W from a larger diameter to a smaller diameter. 
         [0030]    During winding, the wire W is deposited into a spool of wire  511  by the laying head  507  which lays the wire W in a series of loops. Because of this process a torsional force is placed on the wire, causing the wire to twist. It is known that during winding it is not desirable for this twist to migrate upstream beyond the capstan. However, with current systems when this migration occurs it is often undetected until a significant anomaly is detected in the wire W after it is wound in the package  509 . 
         [0031]    Therefore, in an exemplary embodiment of the present invention, the device  113  is placed between the shaping rollers  503  and the capstan  505  to detect the wire feed speed between these components as well as any twisting of the wire W. The information related to wire twist and wire feed speed is transmitted from the monitoring system  111  to a date recording device  513 , which can then be used to evaluate the spool of wire  511  in the container  509 . For example, the data can be used to determine if the spool of wire  511  meets desired parameters for customers and the data can be used to determine the pricing and quality of the wire in the container  507 . Furthermore, the monitoring system  111  can communicate with the control electronics  515  for the winding machine  501  and if the detected twist or wire feed speed is beyond an acceptable range then the control electronics  515  can stop the wire winding machine  501 . This will prevent the entire filling of a container  509  with defective wire. 
         [0032]    In the embodiment shown in  FIG. 5  only a single device  113  is shown between the capstan  506  and the shaping rollers  503 . However, the present invention is not limited to this positioning of the device  113 . Further, embodiments of the present invention can employ more than one device  113  at different positions in the wire winding, drawing or manufacturing process as desired to monitor the wire feed speed and/or twisting of the wire at multiple locations. 
         [0033]    Furthermore, embodiments of the present invention are not limited to use with winding machines  501  for depositing wire W into a container, but can be used in all types of winding machines, including those that wind wire W onto spools and/or reels. 
         [0034]    Embodiments of the present invention can be used for all types of welding in which a welding wire is continuously fed to a welding torch, including but not limited to MIG, flux-cored, and submerged welding. Further, other exemplary embodiments of the present invention can be utilized in dual wire feeder system or in systems where more than one wire feeder is being utilized. In such embodiments the wire feed speed monitoring system can be used to monitor the wire feed speed of the multiple wire feeding operations. 
         [0035]    Further, although the exemplary embodiments have been discussed above in the context of a welding system, the present invention is not limited in this regard as embodiments of the present invention can be utilized in any system in which the feed speed of a wire is desired to be monitored. 
         [0036]    While the invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited to these embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims.