INTRODUCTION

The ARX machine is a standalone indexer. It plays the important role in automation for creating carton spacing in a production line where a conveyor belt feeds a carton sealer or where no zone control has been implemented.  

OPERATION
The ARX indexer functions by briefly pausing the production flows to create a break between back-to-back boxes so the downstream equipment can cycle properly. The indexer has a drop-down roller bed that stops the box. During normal operation, the roller bed is held up by an air cylinder. Adequately spaced boxes are allowed to pass unimpeded. However, if two box come down the line that are too close together or 'back-to- back', the indexer roller bed will drop preventing the second box from entering the downstream equipment while the first box is processed. Once the first box clears and after a short delay provided by an electronic timer (T1), the indexer roller bed lift and send the second box on its way.  Then the cycle repeats. 

OBSERVATION

Carton spacing is created by the positioning of two sensors and any additional delay set by T1. The sensors should be spaced further apart then the length of a single box, to prevent the indexer from dropping unnecessarily. When both photo eye sensors are blocked, presumedly by two back-to-back boxes, the indexer will drop down stopping the second box briefly until the first box clears the second photo eye. Unnecessary stoppage can be cause by:

• Incorrect sensor spacing; too close together.
• 'Always- On' or 'Always-triggered' sensor from misalignment or poor adjustment.
• Damaged sensor
• Insufficient air. 

Additional carton spacing maybe required for downstream equipment that has a cycle time of more than a few seconds or if downstream belt speed is significantly slower than upstream. The timer inside the electrical cabinet may be set to help provide additional delay.

The roller bed lift is pneumatically operated, so pay close attention to the cylinder motion. The roller bed Should drop quickly enough to separate back-to-back boxes and lift fast enough that the box isn't forced or rammed into the frame. 

PROCEDURE

• Verify sensor signals' stability and alignment.
  • Verify power LED indicator.
  • Verify Signal indicator comes on when the sensor is blocked.
    • Adjust sensitivity if required.
    • Adjust L/D if the sensor indicator 'turns-off' when blocked, ie  sensors should be set to 'Light-On.'
    • Remove any reflective objects from the opposite side of the machine or nearby walkway.
• Adjust sensor position spacing to 'longer-than' the box.
  • Place a box in the machine. and verify that only one sensor can be activated at a time.
  • Verify by measuring the length of the box and comparing to the measured distance between sensors.
• Adjust T1 to provide additional spacing if necessary.
• Adjust flow controls on the lift cylinder to ensure quick but controlled operating. minimize banging to prevent frame damage. 
• Air pressure should be set to 35-55psi. 

CONCLUSION

Properly adjusting the ARX will ensure a reliable, automated production line. Note changes in carton sizes during and make adjustments accordingly.