"Otter" Lock-nut for 1" diam. bolt

"Otter" Lock-nut for 1" diam. bolt

This lock-nut, known as the "Otter," is on the roller clutch principle. A hole is bored in the nut tangential to the diameter and in this is inserted a spring bolt at the end of which is a roller pawl of the same outline as the thread. The bolt is held up to its work by a dovetailed slide covering the hole. The nut can be screwed up, but until the slide is raised and the bolt released, the nut cannot be unscrewed, nor, it is claimed, can it slack back.