Abstract: A propelling and braking apparatus for a zero pressure accumulator conveyor includes a driven belt normally in intimate contact with a plurality of supporting rollers and a braking device disposed proximate thereto. Both the driven belt and the braking device apparatus are disposed between and beneath the supporting rollers and are resiliently mounted to a mounting bracket which is adapted to be affixed to one of the side rails of the conveyor. By filling an expansible tube with a pressurized fluid, the driven belt is removed from intimate contact with the supporting rollers and the braking device is caused to come into contact therewith applying braking forces thereto, thereby preventing contact between articles moving along a conveyor.