Zero pressure accumulation conveyor

A zero-pressure accumulating conveyor including a bed defined by rotatable rollers mounted in parallel sidewalls and powered by an endless drive chain. Pneumatic actuators lift the drive chain into engagement with the rollers to empower same. Sensor rollers divide the bed into distinct zones. Sensor rollers are retained in operative position relative to the conveyor bed by unique sensor brackets. A primary sensor roller bracket includes a bore with a piston movable there within; the cooperating secondary sensor roller bracket is spring biased in a first direction. Valves, and pneumatic circuitry controlled by such valves, extend along the length of the conveyor. Such valves are operated by the primary sensor roller brackets to regulate the flow of air pressure into the bores of the brackets and into the actuators. The actuators, when the pressure therein is bled-off, allow the chain in a particular zone to drop out of contact with the rotatable rollers. When the bore in the primary sensor roller bracket is pressurized, the bracket moves in an arc that forces the sensor roller below the plane of the conveyor. In such position, the sensor roller is not actuated as items travel thereover, and the life of the accumulating conveyor is significantly extended.