Fastener collar removal tool

Abstract

A tool for removal of round internally threaded collars from high efficiency aerospace fasteners. The tool includes a central cylindrical pin having a head at one end held against rotation, a non-round extension at the second end and a transverse bore intermediate the ends, containing a ball which is spring biased to project slightly beyond the pin wall. A mandrel assembly surrounds the pin and is rotatable relative thereto. A gripping collet is positioned between the mandrel and pin with collet fingers at one end extending beyond the mandrel and a threaded second end threaded into said mandrel. An axial slot in said collet is adapted to receive said ball when aligned therewith to form a releasable latch mechanism. In operation, the open collet fingers are placed over a threaded collar with said extension in engagement with a corresponding recess in the end of the bolt within the collar. The socket and mandrel are rotated in the collar unthreading direction. The latch mechanism latches the pin and collet together, preventing rotation of the collet. This causes the mandrel to thread into the collet and move downwardly forcing the fingers to grip onto the collar and bringing frictional contact between the mandrel and collet. This frictional contact tries to force the collet to rotate with the mandrel, to thus cause the latch to release and the collet to rotate with the mandrel. Continued rotation of the mandrel causes the collet fingers to further tighten on the collar until the collar unthreads from the bolt.