Abstract: A buffer/brake system is provided for carriers used in an automated assembly system. The rear ends of the carriers are each equipped with a flexible ring that is compressed when an upstream carrier strikes the flexible ring. Compression of the flexible ring causes it to expand and thereby engage the sidewalls of the track and the frictional engagement of the ring against the sidewalls of the track act as a brake for the struck carrier. The ring acts to absorb the shock resulting from the collision between the queued carrier and the oncoming carrier, thereby limiting the transfer of impact forces from pallet to pallet along the track. The ring is carried by a rotatable support which has a laterally extended ring abutment surface. The rotatable ring support is able to swivel, relative to the carrier to which it is attached, as the track makes turns in the assembly system.