ENDURALOCK LLC — Department of Defense SBIR Phase I: AF211-CSO1

Description

Nut plates are commonly used on the inner surface of space and aircraft structures to secure access panels, fuselage fairings, panels on the leading-edge of the wing, and critical electronic equipment. These structures have highly complex three-dimensional surface geometry, which can result in misalignment of the nut plate and the bolts that are used to fasten the panels. These structures may be exposed to high vibration and extreme thermal changes resulting in loss of bolt preload and eventual failure of the assembled structure. Current nut plates rely only on friction for the bolted joint. To overcome the above stated constraints, Enduralock proposes a project to develop a self-aligning nut plate technology with a mechanical locking mechanism that is magnetically actuated. The technology provides for a positively locking solution that is highly vibration resistant with easy reversibility and reusability. The axially spring-loaded nut element design allows for engagement of an off-axis bolt, and it then self-aligns during tightening. It also provides for a fixed position panel bolt retaining ring, which reduces the chance of breakage and foreign object debris (FOD). The nut plate is ideal for in-space robotic assembly and for reducing maintenance time with access panels on aircraft and spacecraft.