Abstract: A door assembly includes a main door body with an interior flange and an exterior flange, both extending parallel and generally away from the main door body. A door frame surrounds the door body when the latter is in a closed position, the door frame having an inner and outer flange, both of the latter extending generally toward the main door body when in its closed position. Two gaskets are provided between a flange of the door frame and a flange of the door, whereby movement of the main door body in a given direction generally perpendicular to the direction in which the flanges extend causes the gasket to be compressed.

Abstract: A method and system for determining the geolocation--i.e., the latitude, longitude, and altitude--of a stationary RF signal emitter from two or more moving observer aircraft. The observers receive signals from the emitter and the system measures the phase difference between the signals. The observers then perform pulse time of arrival (TOA) measurements over a predetermined clock interval, and calculate the time difference of arrival (TDOA) of corresponding, same-pulse, emitter signals. Based on geometric relationships, the system creates a series of circular lines of position (LOPs) for each observer, and computes hyperbolic LOPs based on the TDOA calculations. The system determines emitter location from the intersection of the hyperbolic LOPs and the circular LOPs.

Abstract: A method for determining the geolocation--i.e., the latitude, longitude, and altitude--of a stationary emitter emitting an RF signal. The method employs at least one moving observer to measure electrical phase change of the emitter over two or more successive dwell intervals, and at least two observers, moving or stationary and of known position, to determine the pulse time of arrival of the emitter signal. The phase change measurements are taken using a long baseline interferometer (LBI), and the pulse time of arrival measurements are calculated using short baseline interferometers (SBI). Circles of position are generated from bearing change measurements ascertained from the LBI phase change measurements, and hyperbolic lines of position are generated based on the SBI measurements. The position of the emitter is then determined from the intersection of the circles and lines of position.

Abstract: A method of manufacturing a flat, composite ("pancake") slip ring is described. An assembly of slip rings of conductive material are formed by photo etching or the like into a plurality of annular, concentric conductive rings, the inner and outer diameters of the rings being connected by alignment tabs. A surface of the rings may be masked prior to plating a precious metal on the opposing surface. The slip ring assembly is aligned with the base and bonded to it prior to removing the alignment tabs.

Abstract: A cover for a fill port of a flow controller of a high pressure fitting for filling a cylinder with a pressurized gas. The cover has a slidable cover plate having elongated flexible members attached thereto, such member having a locking projection that cooperatively fits into a locking recess on the cover plate. The cover plate is movable from a first position covering the fill port to a second position away therefrom. Elastomeric means bias the cover plate towards the first position. A fill port adaptor is used to fill the cylinder through the fill port, and may have a cover that prevents operation when the cover is in place. Both covers are adapted to open when the flow controller is properly placed in a cradle that forms part of the fill port adaptor.

Abstract: A all-plastic ZIF (zero insertion force) electrical connector offers the advantages of low cost and ease of manufacturing inherent to plastic. According to a first embodiment of the invention, an all-plastic ZIF electrical connector has a bias means connected to a first half of the connector for providing a bias force to force the first half of the connector against a PCB (printed circuit board) or other circuitry inserted between the first half and a second half of the connector. According to a second embodiment of the present invention, the all-plastic ZIF electrical connector is attached to a flexible printed circuit which allows a first half of the ZIF electrical connector to be flexed slightly to increase the space between the contact fingers to accommodate insertion of the PCB without the need to force the PCB between the contact-making fingers of the connector when the PCB is inserted into the connector.

Abstract: A gas mixing pressure regulator for a closed circuit breathing apparatus comprises a first inlet to provide pressurized air to the breathing apparatus, a pressure responsive demand valve for opening and closing a first inlet, a second inlet for supplying carbon dioxide-free exhaled air from the breathing apparatus, and a mixing chamber for mixing the pressurized air and exhaled air for supplying breathable air to the breathing apparatus. The demand valve is isolated from the mixing chamber by a check valve injector nozzle to prevent contamination thereof and is responsive to pressure demands from the breathing apparatus to ensure reliability, stability and long life.

Abstract: An electrical surveillance measures system for measuring direction of arrival (DOA), i.e., both azimuth and elevation, of a pulsed or continuous wave radar signal from a moving emitter. Either carrier frequency or pulse repetition interval (PARI) Doppler shift are used whereby the ratio of the Doppler shift is measured by a moving observer. The DOA is measured as a unit vector having basis vectors formed from a linearly independent set of observer's velocity vectors. The DOA unit vector has a linear part where the coefficients of the basis vectors are derived directly from the ratios of frequency or PARI measurements taken in three contiguous dwells. The DOA unit vector has a nonlinear part formed from the requirement that the DOA vector have unit magnitude. The unit vector is resolved in the system coordinates in which emitter azimuth and elevation are defined to allow computation of the latter two values.

Abstract: A direction finding antenna system includes a plurality of monopole elements disposed symmetrically around a center of a circular ground plane at the same radial distance from the center and a multimode combiner connected to the monopole elements to provide one or more mode outputs. A phase difference detector determines phase differences between selected ones of the mode outputs to provide azimuth bearing of a detected object. Typically, four or eight monopole elements are used. Placement of the inherently narrowband monopole elements in a bicone structure having a polarizer grid extends the useful bandwidth. Multiband coverage is achieved with a plurality of such antennas connected by a feed cable positioned on the polarizer grid to avoid interference.

Abstract: An electrical slip ring base is constructed of flexible and moldable or extrudible material so as to be capable of being formed into a variety of profiles or shapes. A rigid backing or hub stiffens or reinforces the base member. Any form of conductive rings can be used, and the base member can be formed to accommodate them.