Apparatus is disclosed which provides an entrance gating structure for spacing the entry of containers carried by a conveyor into a testing device. The containers arrive at the testing device under line pressure and are then permitted to enter a testing apparatus where they are conveyed through the testing device and then returned to the conveyor. The gating device is a spring-loaded pivot arm having a pair of legs. One leg stops the flow of containers until the prior container clears the length of the long or other leg. The gate functions automatically without requiring any external operator.