Sensing Minimum Gap Between Boxes on a Conveyor

In a manufacturing environment, a given operation, such as a box taping machine, may require or is most effective, if a minimum spacing or gap between consecutive boxes on its in-feed conveyor exists.  This unique System is designed to solve that need.

This System will sense the minimum desired gap and provide a controlled output such that if the minimum gap is not achieved, it can either stop the conveyor and/or signal an alarm.

To understand this System, a Complete Cycle is defined here as being from the leading edge of the first box to the leading edge of the following box.  The Duty- Cycle is defined here as the percentage of time of that complete cycle that a box is present and passing by a given point along the conveyor.  The System monitors that duty-cycle and makes its controlled decision if that duty cycle is exceeded due to minimum gap not being achieved.

The minimum desired gap is adjustable both electrically and physically, electrically by the System, and physically by the selection of the sensor and its effective beam as well as the angle of the beam with respect to the direction of flow along the conveyor.  The smallest required gap for a given sensor beam would be for the sensor at perpendicular (90 degrees) to the flow of the conveyor, and larger required gaps would be at angles less than 90 degrees (diagonally across the conveyor).

The system logically responds to either infrequent boxes or total absence of boxes on the conveyor by allowing the conveyor to continue to run.

The second component of the System is to ensure that, if in the event that two consecutive boxes are sensed to have not met the minimum gap and therefore the conveyor is stopped and/or an alarm sounded, that if appropriate for the application, after an adjustable/selectable period of time, the conveyor will be automatically instructed to re-start operation and proceed with confirmation of the required gap in the subsequent boxes.   An audible and/or visual alarm can be signaled for each event that the automatic re-start occurs.

Note:  This system is most suitable for a product run of similar box lengths along a conveyor.  It would likely need to be adjusted if a change was made for running some other length of box along the conveyor.