Abstract: An electromagnetic shielding cabinet is provided with a unique latch which does not require shielding. The latch includes a rotatable handle connected to a rotatable cam by a link. The rotatable cam includes a slot which engages a roller stud on a door to open and close the door. Conductive gaskets are provided on the cabinet walls and are engaged by wedges on the door, the rotation of the cam assisting in urging the wedge into or out of the space between flexible finger stock pieces. Because the latch is provided in a small recess in the side wall of the cabinet, no significant interior space of the cabinet is utilized.

Abstract: Disclosed is a fastener adapted for joining a structural member such as a post, rafter, girder, or wire tie downs to concrete or masonry structures. The fastener of the present invention comprises a generally planar elongated member of steel or the like having at least one hole therethrough near one end of the member and having lateral edges near the other end of the member which are inwardly directed scallops. Preferably, the member also includes a hole near the end of the member which has the inwardly directed lateral edges and a hole near the central portion of the member.

Abstract: An objective with two lens elements has a first fully-reflective plane mir between the lens elements, and a second such mirror between the objective and a detector. The outermost lens element and the first mirror are carried in a housing rotatable with respect to another housing carrying the other lens elements and the second mirror. The other housing is rotatable about an axis between the second mirror and the detector. The system may thus do elevation scanning by rotating the first housing, and azimuth scanning by rotating the two housings about the mentioned axis. Image stabilization is accomplished by appropriately stabilizing one or both mirrors.

Abstract: A helmet capable of providing head protection and of carrying various accories. The helmet includes a form-fit inner liner combined with a transparent mask, and an outer shell. The outer shell has a mount by which a display device may be carried. The display device has a flanged ocular end which snaps into a groove formed in the mask. The display device is carried on the mounts by a swivel-mount quick-disconnector. The outer shell may also carry such things as a visor and a radio microphone. The inner liner may carry earphones and may be adapted to connect to a gas mask.