Sure, check this out. The first image is the TriggerBox I created to detect overlapping actors.
Full Res: http://i.imgur.com/XPlccPu.jpg
Now you are going to want to apply movement to all overlapping actors. I wanted to apply movement in the Y direction. You can change this with a variable though as that will probably suit you a lot better.
Full Res: http://i.imgur.com/Df6Y7D5.jpg
So for your needs you would place this box just above the surface of your conveyor belt, with dimensions that fit the size of your conveyor and everything should be just peachy.