Patent ID: 8575484

Claim:
An adjustable-depth ring assembly for connection to an electrical box that is accessible through a wall opening in a wall member disposed forward of the electrical box, comprising an extension ring sized for reception in a central opening of a box cover plate attached to said electrical box, said extension ring defining a cavity, said extension ring being movable relative to the cover plate along an axis extending in front-to-back direction such that an axial distance between the front of the extension ring and the box cover plate can be adjusted to accommodate wall members of different thicknesses, an abutment device projecting outward beyond a perimeter of the extension ring for abutting a front surface of said wall member when the extension ring is moved to an installed position, an electrical device in said cavity fastened to the extension ring, and a finish cover plate attached to the electrical device at a location in front of the extension ring, said extension ring, abutment device, electrical device and finish cover plate forming a pre-assembled unit free of any connection with said box cover plate and said electrical box prior to field installation of the unit to connect the unit to the box cover plate and the electrical box.