In large-scale machines used in the manufacture of commercial aircraft, rivets or bolts (referred to hereinafter as fasteners) are fed at high speeds from a fastener feed cabinet through a feed tube to a drilling and riveting end-effector which quickly drills the required holes and then injects the fasteners into the drilled holes. Such a machine will typically include a number of individual modules for use with fasteners of various sizes. While generally such machines operate very quickly and reliably, typically up to 14 drilling and riveting operations per minute, occasionally the fasteners are misfed, such as being positioned backwards in the fastener tube or two fasteners are fed together, as two examples. In such a case, it is important to identify the incorrectly fed rivets and to very quickly eject them from the rivet injection system.
Historically, this has been done in various ways, usually with a mechanical system, or an air blast. Sometimes the injection system must be stopped and the incorrectly fed rivets removed by hand. It is important that the system for clearing rivets be fast and reliable, thus increasing overall machine reliability.