US Patent 9844818 Flexible and extendible drill bit assembly

An extension assembly configured to permit a user to drill a hole through inaccessible areas in a wall is disclosed. The extension assembly includes a flexible, solid core rod having first and second ends and a holding means. The rod is configured to extend through a hole in a wall cavity and flex therein to position a tool bit at an inaccessible location in the wall cavity and permit a user to drill a hole through a substrate at the inaccessible location. The holding means is secured to the second end of the rod for releasably holding a tool bit for rotation with the rod and includes a sleeve adapted to slide axially along a body of the holding means between a secured position where a tool bit is securely held within the holding means and a release position where the tool bit is released from the holding means.