A ball-lock type fastening device for connecting a work piece to a structure is disclosed. The fastening device includes a number of features designed to improve the reliability, repeatability and strength of the locking mechanism compared to traditional ball-lock fasteners. The features include the shape of the locking balls, the shape of the retention housing which engages the locking balls, and mechanisms for controlling deployment and retraction of the locking balls.

A magnetic fastener assembly for securing an access panel to an aircraft structure. A panel magnetic foundation member is rigidly secured to a surface of the panel facing the aircraft structure and a land magnetic foundation member is rigidly secured to a surface of the aircraft structure facing the panel. A planar magnet is positioned between the panel magnetic foundation member and the land magnetic foundation member and being magnetically coupled thereto so as to secure the panel to the aircraft structure. A separation device, such as a pneumatic bladder, is positioned between the panel and the land structure and adjacent to the magnet, and is rigidly secured to the aircraft structure. The separation device is actuated to apply pressure to the panel and break the magnetic attraction between one or both of the panel magnetic foundation member and the magnet or the land magnetic foundation member and the magnet.

A method of noninvasively determining desired positioning of a component beneath a substrate is described. The component has a concealing surface longitudinally separated by a substrate body from an accessible surface of the substrate. A component having longitudinally differing activated and deactivated positions is provided. The component is located longitudinally beneath the concealing surface of the substrate. The accessible surface of the substrate is inspected with an inspection device while the component is beneath the concealing surface. With the inspection device, at least one of an activated and a deactivated position of the component is detected. The detected activated and/or deactivated position of the component is indicated, in a user-perceptible format. An apparatus for noninvasively determining desired positioning of a component beneath a substrate is also provided.

A fastener for highly curved access panels on aircraft or other structures, featuring a bottom-grasping design allowing for an unblemished outer panel surface, simple and rapid pneumatic fastener actuation, built-in clamping pre-load, and full retractability of the fastener inside the supporting structure. The fastener includes a Belleville spring with a piston centrally disposed therein, where the piston and spring deflect outward upon application of pneumatic pressure. A pressure chamber within the piston has inlet and outlet orifices designed so that the pressure in the piston chamber gradually increases, requiring several seconds to reach a pressure which causes locking dogs in the piston to deploy radially into a cavity in the access panel. When pressure is removed, the Belleville spring relaxes, the locking dogs grasp a lip of the cavity, and the access panel is latched onto the structure with a clamping pre-load. A pneumatic sequence for unlatching is also provided.

A ball-lock type fastening device for connecting a work piece to a structure is disclosed. The fastening device includes a number of features designed to improve the reliability, repeatability and strength of the locking mechanism compared to traditional ball-lock fasteners. The features include the shape of the locking balls, the shape of the retention housing which engages the locking balls, and mechanisms for controlling deployment and retraction of the locking balls.