Tethered fastening device

A tetherable cavity washer, comprising:

• a substantially planar base surface having a fastener aperture extending longitudinally therethrough, the base surface having a base surface perimeter, and the entirety of the fastener aperture being located in a laterally spaced-apart relationship with the base surface perimeter;
• a longitudinally oriented wall extending longitudinally upward to at least a first longitudinal distance from at least a portion of the base surface perimeter;
• and
• two tether apertures extending laterally through the wall, the tether apertures being laterally spaced apart along the wall, and both of the tether apertures being laterally arranged along the wall in a rotationally asymmetric configuration.

A method of tethering a penetrating fastener, the fastener having a longitudinally separated fastener head and fastener tip spaced apart by an elongate, longitudinally oriented fastener shaft, the method comprising:

• providing a tetherable cavity washer, having:
• a substantially planar base surface having a fastener aperture extending longitudinally therethrough, the fastener aperture having at least one lateral dimension less than a corresponding lateral dimension of the fastener head,
• a longitudinally oriented wall extended longitudinally upward to at least a first longitudinal distance from at least a portion of the base surface to form a concave fastener cavity, and
• two tether apertures extending laterally through the wall, the tether apertures being laterally spaced apart along the wall, and both of the tether apertures being laterally arranged along the wall in a rotationally asymmetric configuration, a first one of the tether apertures being located a second longitudinal distance from the base surface and a second one of the tether apertures being located a third longitudinal distance from the base surface, both the second and third longitudinal distances being greater than a longitudinal thickness of the fastener head;
• inserting at least a portion of the fastener shaft through the fastener aperture;
• receiving at least a portion of the fastener head within the fastener cavity;
• providing an elongate tether, having first and second tether ends separated by a tether body;
• extending the tether body simultaneously through both of the tether apertures;
• and
• substantially blocking the fastener head, with a portion of the tether body extending between the two tether apertures, from exiting the fastener cavity through movement oriented longitudinally away from the base surface.