Abstract: A method and apparatus for processing vehicles which are moved through a conduit by air through sequential zones one, two and three. Preferably, the zones are inclined downwardly towards downstream for aiding movement of the vehicles downstream by gravity. Zone one is a storage zone which preferably has vents adjacent its upstream end and its downstream end for controlling the speed of movement of vehicles into zone one and from zone one to zone two. Zone two is the processing zone which receives vehicles from zone one and releases the vehicles to zone three. Zone two includes an air blocking vehicle stop at its downstream end against which a first vehicle is held, and includes a holding arm which holds a second vehicle while the leading first vehicle is released. The first vehicle is released to zone three, but only when three is clear of vehicles and a second vehicle is positioned behind the first vehicle.

Abstract: A releasable stop for releasably stopping a vehicle moving through a conduit. A stop gate is supported for pivotal movement into and out of the path of movement of the vehicle. First and second arms are pivotally connected together between the gate and a support and a pneumatic piston and cylinder assembly actuates one arm for moving the gate between a closed and opened position. The pivoting arms are moved into or slightly past a dead center position when the gate is in the closed position whereby the impact of a vehicle engaging the gate will be transmitted to the support instead of to the piston and cylinder assembly. When the gate is closed, the dead center position of the arm maintains the stop gate in a locked position. The stop gate may be sized and shaped to entirely block the conduit to provide a dead end air cushion stop assist.