Abstract:
The present invention is a system for electronically controlling the movement of a pin assembly used in a valve gate mechanism of an injection molding machine. The system of the present invention includes at least one valve which is part of an injection molding machine, as well as a graphical user interface which is operable for controlling the injection molding machine and the valve. Additionally, the present invention also includes controlling the injection molding machine electronically for improving the control over the opening and closing of the valves.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a graphical user interface for electronically controlling a valve in an injection molding machine. 
       BACKGROUND OF THE INVENTION 
       [0002]    Injection molding machines are generally known. Typical injection molding machines use hydraulic control methods for opening and closing various types of valves, commonly referred to as gates, or valve gates, which are opened and closed at particular times for allowing a molten material to flow into a mold. Injection molding machines typically have a mold, or cavity, which is used with the gates, with the gates being placed in various positions relative to the mold, for facilitating the flow of molten material into the mold. Each of the valve gates can be set up to open and close at specific times measured from the initial start-up of the machine to properly allow for the molten material to flow into different parts of the mold, or at different points during the operation of the machine as the position of the machine changes, creating the desired part. 
         [0003]    The location of the molten material being injected into the mold and the time duration of injecting the molten material, both have an effect on the outcome of the part. However, the valve gates are typically controlled through the use of a hydraulic control which does not allow for a precise opening and closing of each of the valve gates. When hydraulic control is used, each of the valve gates can only be placed in either a fully open or fully closed position. With the advancement of the different types of materials used in injection molding machines and the increase in complexity of the parts produced by injection molding machines, it is desirable to have greater control over the valve gates, allowing the valve gates to have various positions other than being fully open or fully closed. 
         [0004]    Accordingly, there exists a need for an injection molding machine having an electronic control which allows for improved control over the movement of various valve gates. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is a system for electronically controlling the movement of a pin assembly used in a valve gate of an injection molding machine. The system of the present invention includes at least one valve which is part of an injection molding machine, as well as a graphical user interface which is operable for controlling the injection molding machine and the valve. Additionally, the present invention also includes controlling the injection molding machine electronically for improving the control over the opening and closing of the valves. 
         [0006]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0008]      FIG. 1A  is a portion of a flow chart of a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0009]      FIG. 1B  is another portion of a schematic of a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0010]      FIG. 1C  is another portion of a flow chart of a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0011]      FIG. 1D  is another portion of a flow chart of a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0012]      FIG. 1E  is a schematic of a system incorporating a graphic user interface used for controlling an injection molding machine, according to the present invention; 
           [0013]      FIG. 2  is a screen shot of a start-up screen used in a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0014]      FIG. 3  is a run screen used in a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0015]      FIG. 4  is a calibration screen used for a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0016]      FIG. 5  is a password screen used in a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0017]      FIG. 6  is a manual run screen used in a graphical user interface for an injection molding machine having electronic control, according to the present invention; 
           [0018]      FIG. 7  is a recipe selection screen used in a graphical user interface for an injection molding machine having electronic control, according to the present invention; and 
           [0019]      FIG. 8  is a recipe edit screen used in a graphical user interface for an injection molding machine having electronic control, according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0021]    The present invention is directed toward a visual control process used for valve gates, in which the system provides electronic control from one to twenty-four valve gates used in an injection molding machine. 
         [0022]    The control process of the present invention also includes various control parameters which are used for controlling the position of a pin used in a valve gate assembly. The present invention incorporates the use of a touchscreen display, where a symbol representing each valve that is being controlled is shown on the screen, and the symbol is simply touched to access the various parameters for controlling the valve. Some of the parameters are press position, trigger time, and flow gap. The press position and trigger time are used separately from one another, i.e., if the press position parameter is used, the trigger time is not used, and vice versa. Additionally, the present invention also incorporates the use of electronic control over the valve gate assembly, as opposed to hydraulic control. The use of electronic control provides increased control over the movement of the valve gate, allowing for more precise control of the flow of molten material in the injection molding machine. 
         [0023]    The present invention can be practiced in conjunction with the Internet, World Wide Web, intranets, extranets, electronic media (e.g., CD/DVD-based systems), or the like. The system of the present invention is a web-based server that runs on an embedded Windows CE platform. The web-based server system can be accessed via a client web browser over an Ethernet-based Land Area Network (LAN) from any computer capable of running Internet Explorer or compatible Browser. A local touch screen is also available. The web-based server is a convenient and cost effective method for displaying zone status, logging data, storing recipes, and setting zone and system parameters. 
         [0024]    In order to fully appreciate the benefits and features of the visual control process for valve gates of the present invention, it is assumed that an individual practicing the present invention will have: access to a computer (and is conversant with the basic functions thereof); an Internet service provider (“ISP”) (e.g., AOL, JUNO, or the like) with e-mail capability; a Web browser (e.g., INTERNET EXPLORER, NETSCAPE, or the like); any required plug-ins (e.g., FLASH, SHOCKWAVE, JAVA VIRTUAL MACHINE, or the like); and have the ability to navigate successfully to any given uniform resource locator (“URL”). In order to further appreciate the benefits and features of the present invention, the user will also have an understanding of injection molding systems and valve gates. Valve gates are devices used for facilitating the delivery of a molten material into a mold of an injection molding machine; a valve gate typically includes a pin which is moved to open and close the gate. Injection molding machines typically include a source of molten material, which then flows through various channels, ports, and the like, into a mold; the valve gates allow the molten material to flow into the mold when the gates are open, and prevent the molten material from flowing in to the mold when the gates are closed. Each gate has a servo drive and a servo motor, and a servo valve. The servo valve is another term used to describe the pin, the servo drive is the electronics used to control the pin, and the servo motor is the device which mechanically moves the pin. 
         [0025]    An example of an injection molding system having valve gates is discussed in co-pending application Ser. No. 11/888,584, the entire application of which in incorporated herein by reference. 
         [0026]    A flow chart demonstrating the use of a system for the visual control process of valve gates, according to the present invention, is shown in  FIGS. 1A-1D  generally at  10 . The first step is for the user to activate the visual control process system  10  of the present invention, e.g., by clicking on an icon or the like on a computer. The present invention incorporates the use of a touch screen, which is used for navigating the system  10  of the present invention. By way of a non-limiting example, a user could navigate to the URL of a main Web Site  12  that contains the visual control process system  10  of the present invention (e.g., with the aid of a Web browser, such as INTERNET EXPLORER, NETSCAPE, or the like). 
         [0027]    Referring to the Figures generally, from the main Web Site  12 , the user will arrive at the Startup Screen  14 . The Startup Screen  14  has three main controls generally shown at  16 , the “Run” button  18 , the “Recipes” button  20 , and the “Config.” button  22 . Anytime the user presses the Config button  22 , the user will access the Startup Screen  14 . Anytime the user presses the “Run” control button  18 , graphic displays of each of the valve gates will appear, the function of which will be described later. The Recipes button  20  is what is used for accessing recipes. Recipes are used for defining what parameters will be used for controlling the movements of the gates; one or more recipes can be used, with each having different parameters. Since the system  10  operates through the use of a touch screen, a user simply touches the Run Button  18 , the Recipes Button  20  or the Config Button  22 , as well as any other buttons used in the operation of the system  10 . 
         [0028]    Along the top of the Startup Screen  14  are four system status indicators, shown generally at  24 . The system status indicators  24  include the Mold Closed Status  26 , Drive Status  28 , System Control Status  30 , and Mold Temperature  32 . Any one of the system status indicators  24  will prevent the system  10  from running if their status is not operational. In the present embodiment, the system status indicators  24  will appear having white lettering on a green background with the status is ready to run, or black lettering on a gray background when their status will prevent the system from running. 
         [0029]    One of the parameters controlled by the user is the operating mode  34 . The operating mode  34  in this embodiment is a drop down menu where one of three different modes of operation are selected; this is shown in  FIG. 1A  at step  36 . The three different modes are “Off Mode”  38 , “Manual Mode”  40 , and “Auto Mode”  42 . In the Off Mode  38 , the system becomes idle, in Manual Mode  40 , the system  10  is controlled with the buttons on the manual mode screen (which will be described later). 
         [0030]    The Auto Mode  42  is the typical mode of operation, where the gates open and close automatically as defined by the active recipe. As mentioned above, pressing the Run Control button  18  will allow the user to access the run screen, shown in  FIG. 3  at  44 . The Run Screen  44  shows several icons  46  which represent each of the valve gates. 
         [0031]    When the Operating Mode  34  that is chosen is the Manual Mode  40  of operation, this allows for manual control over the motion of the valve gates  46  which is most useful in terms of troubleshooting and mold maintenance. If the user selects the Manual Mode  40  of operation from the drop down menu of the Operating Mode  34 , the user will be taken to a Manual Mode Screen, generally shown in  FIG. 4  at  48 . The Manual Mode Screen  48  includes a Toggle Purge Status Button  50 , a Minimum Operating Temperature Input field, shown generally at  52 , and a Set button  54 . There is also a listing, shown generally at  56  for all of the gates. The listing  56  includes the Gate Number  58 , the Home button  60 , the Flow Gap  62 , an Open button  64 , a Close button  66 , a Reset button  68 , and a Servo Status Indication  70 . 
         [0032]    The Toggle Purge Status button  50  is pressed when it is desired to purge machine and open all the valve gates  46  fully if the tool is above operating temperature. The minimum operating temperature is entered into the Minimum Operating Temperature field  52 , and the Set button  54  is pressed to make the value entered into the Minimum Operating Temperature field  52  the minimum operating temperature for the system  10 . 
         [0033]    When at the Manual Mode Screen  48 , the Home button  60  is used to apply the homing force to the pin, the function of which will be described later. The Open button  64  is used for opening the gate, the Closed button  66  is used for closing the gate, and the Reset button  68  is used for resetting the gate to an initial position. 
         [0034]    Referring back to  FIG. 2 , the startup screen  14  also includes an “Auto Mode” field, shown generally at  72 , which will only have an effect on the operation of the system  10  when the Operating Mode  34  is set to Auto Mode  42 . In this embodiment, the Auto Mode field  72  is a drop down menu, having two choices; they are position  74  and time  76 . When position  74  is chosen, movement of the valve gate  46  is triggered by the position of the press screw (the press screw is a device used for driving molten material into the mold, as the molten material is driven toward the mold, the valve gate(s)  46  must be open for the molten material to flow into the mold); when time  76  is selected, movement of the valve gate  46  is triggered by the elapsed time starting when the mold closed  26  input and run timers input (the function of which will be described later) are both active. 
         [0035]    The startup screen  14  also includes a Length Units Field, generally shown at  78 , a Temperature Units Field, generally shown at  80 , a Zero Position Encoder  1  button  82 , a Zero Position Encoder  2  button  84 , a Toggle Thermocouple Polarity button  86 , and an Advanced Gate Config button  88 . 
         [0036]    The Length Units Field  78  in this embodiment is a drop down menu which allows for the user to select between metric (mm) units  79  or English (inches) units  77  to be used for all length-related parameters and indicators. The Temperature Units Field  80  in this embodiment is also a drop down menu which allows the user to either select metric (° C.) units  85  or English (° F.) units  87  to be selected for all temperature-related parameters and indicators. 
         [0037]    There is one button for each press position encoder in the system. In this embodiment, there are two press position encoders used for the system  10  of the present invention, a first Press Position Encoder  81 , and a Second Press Position Encoder  83 . A press position encoder is a device used for determining the position of a press screw used in an injection molding machine for injecting molten material into a mold. The value assigned to the position of the press screw as the system  10  operates is referred to as the “press position value.” The Zero Position Encoder  1  button  82  zeros out the press position value controlled by the first Press Position Encoder  81  (i.e., Position Encoder  1 ), and the Zero Position Encoder  2  button  84  zeros out the press position value control by the Second Press Position Encoder  83  (i.e., Position Encoder  2 ). Before a recipe is run, the Position Encoders  81 , 83  must be reset to zero, or “zeroed out”, to ensure that the position of the press screw for the injection molding machine is monitored correctly as a recipe is run. The position of the press screw after the Zero Position Encoder  1  button  82  and the Zero Position Encoder  2  button  84  are pressed is referred to as the “zero press position.” The “zero press position” is used as the initial reference point after the press screw begins operation to determine when the valve gates  46  are to open and close. 
         [0038]    With regard to the Toggle Thermocouple Polarity button  86 , pressing this button  86  will change the polarity of the thermocouple used in the system  10 . During installation, the wires for the thermocouple can be installed backwards accidentally. Pressing the Toggle Thermocouple Polarity button  86  has the same effect as swapping the thermocouple wires without actually having to physically swap the connections. 
         [0039]    If the Advanced Gate Config button  88  is pressed, the system  10  will bring up a Password Screen, shown generally in  FIG. 5  at  90 ; once the user enters in the proper password, the user will arrive at the Pin Setup Screen shown generally at  92  in  FIG. 6 . The user will want to access the Pin Setup Screen  92  when performing the pin setup process; the pin setup process is the process of physically attaching the pins for each of the valve gates  46  in the mold to the servo motors. The servo motors are the devices used for moving the pins between an open and closed position and are controlled by the servo drives. There are several Pin Setup buttons  94  included on the Pin Setup Screen  92 . There is a Toggle TC Calibration Mode Button  96 , which commands the system to go into calibration mode, where the thermocouple circuit (not shown) is calibrated by measuring known reference voltages in a calibration sequence. 
         [0040]    The Pin Setup Screen  92  also includes a listing of the gates, shown generally at  98 , and each gate having a number  100 . Each gate  100  in the listing  98  also has three buttons, a Setup button  102 , a Home button  104 , and a Set Force button  106 . There are also fields for the Homing Force  108 , which is expressed as a percentage of the full force, and the Flow Gap  110 . As mentioned above, the pin setup process is the process of physically attaching the pins for each of the gates in the mold to the servo motors. The pin setup process can only be performed when the Operating Mode  34  is set to Manual Mode  40 , and the user accesses the Pin Setup Screen  92 . 
         [0041]    When the user is at the Pin Setup Screen  92 , the Setup button  102  is pressed to cause the servo motor to go to a specific reference position relative to the end stop position; the pin for the gate is then attached. Once the pins are attached, the Homing button  104  is then pressed, and the pins are then commanded to their closed position. The Homing Force  108  is a percentage of the full force that is applied to the pins to ensure that the pins are flush with the mold when closed. The percentage is entered in the field for the Homing Force  106 . Once the percentage is entered, the Set Force button  108  must be pressed to save the value entered into the field for the Homing Force  108 . Pin setup allows the torque limit (Homing Force  108 ) to be set for the servo drive for each gate. When the Homing Force  108  is changed, the gate will calibrate (i.e., finds) the home position again using a new torque limit (which is obtained when the pin is re-seated). 
         [0042]    There is a Homing Force  108  which is programmable for each gate  46  in the gate listing  98  that is used in each recipe. As mentioned above, the Homing Force  108  for each gate  46  is the force exerted by the servo motor when homing the pin during the pin setup process and the torque limit during operation, and is a percentage of full force. The default value entered into the field for the Homing Force  108  is 20%; therefore, the default value for the Homing Force  108  is 20% of that of the full force. The range for the Homing Force  108  is between 1 to 100%. 
         [0043]    Referring back to the Startup Screen  14 , if the user presses the Recipe button  20 , the user will arrive at the Recipe Selection Screen, generally shown at  112  in  FIG. 7 . The Recipe Selection Screen  112  allows the user to activate or edit existing recipes, create new recipes, or delete recipes. On the Recipe Selection Screen  112  there are three recipes, shown generally at  114 . Each recipe  114  includes several buttons, an Activate button  116 , an Edit button  118 , and a Delete button  120 . There is also a New Recipe button  122 , the function of which will be described later. Each recipe  114  also includes a field  124  which includes a description of the recipe  114 , if desired, the name of the recipe  114 , as well as the date the last time the recipe  114  was modified. 
         [0044]    When the user presses the Activate button  116  for a specific recipe  114 , that specific recipe  114  will become the current recipe  114  used by the system  10  for operation of the valve gates. Pressing the Delete button  120  deletes the recipe  114 . Pressing the Edit button  118  opens the recipe  114  for editing. Each recipe  114  is edited separately, and pressing one of the Edit buttons  118  opens up only one recipe  114  for editing. 
         [0045]    Once the recipe Edit button  118  is pressed, the user will arrive at the Recipe Edit Screen, shown generally at  126  in  FIG. 8 . Each recipe  114  is a group of machine setup parameter values saved together under a user created name so that they can be reloaded for use and/or editing to create a new recipe  114 . Each recipe  114  is a record in a database. There are several fields and buttons on the recipe edit screen  126 . There is a Save Recipe Button  128 , a Revert Recipe Button  130 , and a Create New Gate Button  132 . The Save Recipe button  128  saves changes to the recipe  114 , and the Revert Recipe button  130  cancels any changes made to the recipe  114  and returns all the parameters of the recipe  114  to their last saved values. The Create New Gate button  132  adds the next sequential gate number to the recipe  114  that will be used. 
         [0046]    It can be seen in  FIG. 8  that the Recipe Selection Screen  126  also has a set of parameters which are chosen for each valve gate  46 . In this embodiment, there are two gates shown on the Recipe Selection Screen  126 , but it is within the scope of the invention that more or less gates may be used. As mentioned above, the Create New Gate button  132  adds control over the operation of a new gate to the recipe  114 ; as shown on the screen, there are two gates  46 , but if it is desired to add an additional gate  46 , the Create New Gate Button  132  is pressed. 
         [0047]    There is also a Recipe Name Field  134 , a Recipe Description Field  136 , a Position Encoder Count Field  138 , and a Minimum Operating Temperature Field  140 . The Recipe Name field  134  is used for a short label which is used to reference a recipe  114 . The Recipe Description field  136  is the field in which the operator is allowed to enter information and various notes pertaining to the recipe  114 . The information entered into the Recipe Name field  134  and the Recipe Description field  136  is the information shown in the field  124  on the Recipe Selection Screen  112 . The Position Encoder Count field  138  is the number of press position encoders used in a recipe  114 ; there can be one or two press position encoders, with the default value for the Position Encoder Count field  138  being one. 
         [0048]    The Minimum Operating Temperature field  140  is the manifold temperature above which movement of the pin is enabled. The units for this field  140  may be Fahrenheit or Celsius, depending upon the units selected in the Temperature Units field  80  on the Startup Screen  14 . When the manifold temperature is below the value entered into the Minimum Operating Temperature field  140 , the servo drives are disabled so that the servo motors will not move. The only exception to this is in Pin Setup Mode (where the user has accessed the Pin Setup Screen  92 ), where the pins are allowed to move regardless of manifold temperature. 
         [0049]    There is a Gate Number Indication Field, generally shown at  142 , a Gate Enabled Field, generally shown at  144 , which in this embodiment is a check box, as well as a Use Position Encoder Field, shown generally at  146 , and a Gate Type Field, shown generally at  148 . 
         [0050]    The Gate Number Indication Field  142  simply identifies the gate  46  by number. The Gate Enabled Field  144  as mentioned above is a check box, and when a new gate  46  is added, the check box is checked by default, meaning that when a new gate  46  is added to a recipe  114 , the gate  46  will be enabled by default. 
         [0051]    The Use Position Encoder Field  146  is assigned a default value of one, but may also have a value of two because there are two possible press position encoders that can be assigned to each valve gate  46  in the recipe  114  (which is also why there is also a Zero Position Encoder One Button  82  and a Zero Position Encoder Two Button  84 ). By way of explanation but not limitation, if Press Position Encoder Two (the second Press Position Encoder  83 ) is assigned to the fifth gate in the seventh Recipe, then all press position triggers in the seventh recipe for fifth gate use Press Position Encoder Two. 
         [0052]    The Gate Type Field  148  in this embodiment is a drop-down menu where the type of gate  46  is selected. This Field  148  determines the particular graphic that will be used on the Run Screen  44  for the gate  46  when the recipe  114  is running. The Run Screen  44  displays several different types of graphics that are used to show the various types of gates  46  being used for a particular recipe  114 . 
         [0053]    There are also several buttons used for defining the parameters of each gate  46 ; there are three “gate parameters” and a list of “trigger parameters.” As mentioned above, a valve gate  46  is a device used for allowing or preventing the flow of molten material into a mold. A “trigger parameter” or “trigger point” is a point where the operation of the valve gate  46  changes. There are up to 256 trigger points that can be defined for each gate  46 . For each gate  46  there is a Create Trigger Button  150 , and a Delete Gate Button  152 . Each trigger also has several buttons and fields, there is an Up Button  154 , a Down Button  156 , and a Delete Trigger Button  158 . The Up Button  154 , Down Button  156 , and Delete Trigger Button  158  are used in conjunction with the fields; they are a Press Position Field, generally shown at  160 , a Trigger Time Field, generally shown at  162 , a Flow Gap Field, generally shown at  164 , and a Servo Rate Field, generally shown at  166 . 
         [0054]    The Create Trigger Button  150  adds a new line to the trigger list of each gate  46 . The Up Button  154  moves a trigger up one position on the list, and the Down Button  156  moves a trigger down one position on the list. The Delete Trigger Button  158  deletes a trigger from the list. 
         [0055]    As mentioned above, the point at which operation of the gate  46  changes is referred to as a “trigger point.” The trigger points can be based on either the position of the press screw in the machine  174 , or time. This decision is made when the user selects either Position  74  or Time  76  from the Auto Mode field  72 . There are as many trigger points as necessary to properly perform the operation of gate  46 . If Position  74  is chosen from the Auto Mode field  72 , then the Press Position Field  160  will be used to determine the position of the gates during the operation of the machine  10 . Conversely, if Time  76  is chosen from the Auto Mode field  72 , the Trigger Time field  162  is used to determine the position of the gates during the operation of the machine  10 . 
         [0056]    The Press Position Field  160  is the trigger parameter which is the press position value of the press screw at which to start a movement of a valve gate  46  to an associated Flow Gap  164 . A flow gap is the amount of space created when the pin of the gate  46  is opened to allow molten material to flow through the gate  46 . The value entered into the field for the Flow Gap  164  will be the distance the gate  46  is opened. The value entered into the field for the Flow Gap  164  is the same value used for the Flow Gap  62  on the Manual Mode screen  48  and the Flow Gap  110  on the Pin Setup Screen  92 . The values entered into the Press Position Field  160  are continuously compared to the present value of the assigned press position encoder  81 , 83  to determine when the trigger point is reached at which point the pin will change position to the next Flow Gap  62 , 110 . The values entered into the Press Position Field  160  are only used in Auto Position mode (when the Operating Mode  34  is selected to be Auto Mode  42 , and the Auto Mode Field  72  is set to “Position”  74 ). The default value for the Press Position Field  160  is 0.00 inches. The range is ±60.00 inches, or ±1500.0 mm. However, in the Field  160  itself, the decimal point is only for display purposes; the values are fixed decimal point, no floating, so for inches the values are really ±6000, and for millimeters they are ±15000. 
         [0057]    Referring to  FIG. 1E , the present invention also includes a device for functioning as a data bank (for storing information, such as information relating to recipes  114  and other machine setup parameters), such as a computer  168  having a display  170 . The computer  168  is also connected to a controller  172 , which in this embodiment is a low-level controller  172  which includes an Input-Output Printed Circuit Board (IOPCB). The controller  172  receives commands from the computer  168 , and then sends a signal to command the injection molding machine  174  to perform the desired operation of the valve gates  46  having the pins. Even though the movement of the pins used in the gates  46  is measured in inches or millimeters, the computer  168  measures the movement in “pulses.” When performing calculations and data storage, the computer  168  must always convert the values to pulses for control use and storage of the data for the recipe  114 . In this embodiment, when position  74  is being used as the trigger point, and Press Position Field  160  is also being used, the position encoders  81 , 83  will generate two-hundred pulses per inch of movement of the pin. Therefore, in order to convert the movement of the pin measured in inches to pulses, the distance the pin moves measured in inches is multiplied by two-hundred. For example, movement of one-and-a-half inches would be the equivalent of three-hundred pulses. 
         [0058]    If millimeters are the units being used, the conversion factor from millimeters to pulses is accomplished by multiplying the number of millimeters by one thousand, and then dividing by one-hundred-twenty-seven. It should be noted that there are several points or steps in the process where the operation of the machine  174  changes based on the recipe  114  and how the material is to be injected into the mold. When the controller  172  seeks another command, and the last trigger point has been reached, the computer  168  will respond with a default value, meaning that the last trigger point has been requested, and the valve gate  46  should not make any more movements in the cycle. 
         [0059]    As described above, there are two modes of operation that can be selected from the Auto Mode field  72 , they are position  74  and time  76 . When time  76  is selected, there various timers, or “Run Timers”  176 , which are activated once the machine  10  begins operation (more specifically, when the press screw begins to move after being in its initial position). The Trigger Time Field  162  is the parameter which is the time measured in seconds to wait from the time that the Run Timers  176  input is activated before starting movement of a valve gate  46  to the associated Flow Gap  62 , 110 . Once again, the Triggers Time field  162  is only used in Auto Time mode (when the Operating Mode  34  is selected to be Auto Mode  42 , and the Auto Mode Field  72  is set to “Time”  76 ). The default value in the Trigger Time Field  162  is zero. The ranges of values that may be entered into the field are from 0.00 to 99.99 seconds. Once again, there are as many trigger points as necessary (up to 256) to properly perform the operation of the gate  46 . When the controller  172  seeks another command, and the last trigger point has been reached, the computer  168  will respond with a default value, meaning that the last trigger point has been requested, and the valve gate should not make any more movements in the cycle. 
         [0060]    The Flow Gap Field  164  is used for displaying a value; for each Press Position  160  or Elapsed Time Trigger  162  there is an associated Flow Gap Field  164 . As mentioned above, the value shown in the Flow Gap Field  164  is the same value used for the Flow Gap  62  in the Manual Mode Screen  48 , and the same value as the Flow Gap  110  shown in the Pin Setup Screen  92 . The Flow Gap  62 , 110  is the position the pin is moved to relative to a fully closed valve gate  46 . The value in the Field  164  when the valve is fully closed is zero, and the range for the Field  164  is from 0.000 inches to 0.750 inches, or from 0.00 mm to 19.00 mm. When the system  10  is using trigger points for a gate, the value in the Field  164  for the Flow Gap  62 , 110  must be in thousandths of an inch. The Flow Gap  62 , 110  value used by the software of the system  10  and the gates is always in thousandths of an inch, so the computer  168  must convert any measurements in millimeters to thousandths of an inch before they can be used. 
         [0061]    The Servo Rate Field  166  is the field in which a value for the Servo Rate is entered. For each Press Position Trigger  160  or Elapsed Time Trigger  162 , there is an associated Servo Rate  166 . The Servo Rate  166  is the rate (or speed) in which the pin moves such that the gate  46  is at the specified Flow Gap  62 , 110 . The range for the Servo Rate  166  is 0.01 inches/sec to 5.00 inches/sec, or 0.3 mm/sec to 127.0 mm/sec. 
         [0062]    After each recipe  114  is completed, the user can simply press the Save Recipe button  128  to save the changes made set forth in the manner above, if any, made to the recipe  114 . If the user does not want to save any of the changes made, the user will simply press the Revert Recipe button  130  to restore the various parameters of the recipe  114  to the last set of saved parameters. Once the user has decided whether or not to save the recipe  114 , the user may press the Activate button  116  to make a specific recipe  114  the recipe that will be run by the system  10 . Once a specific recipe  114  is activated, the Run button  18  is pressed to activate the system  10 , and view the Run Screen  44 . The user may also, once at the Run Screen  44 , touch any one of the gates  46  to monitor a specific gate  46  and view the various operating parameters for each gate  46 . 
         [0063]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.