FIRE RETARDANT FOAMS *See address below. NASA Case No. ARC-10098 Corresponding to U.S. Patent No. 3,549,564 Filed 2-5-68 Issued 12-22-70 This invention improves upon polyurethane foams as fire resistant materials by improving their characteristics and by imparting fire suppressant and fire retardant characteristics. The main structure of the material is a rigid or semi-rigid polyurethane foam, preferably of a highly branched structure, in which are incorporated one or more materials to impart special properties. Modified foams have been developed which provide effective protection for thermally sensitive structures against the destructive action of fuel-fires. The invention relates to the modification of closed cell rigid and semi-rigid polyurethane foams in the density range of from 0.50 to 50 pounds per cubic foot. The modifying agents include three types: a certain class of alkyl halide resins, a certain class of inorganic salts, and encapsulated halogen bearing volatile molecules. The modified foam may then be applied by conventional methods. Outstanding protection against fire has been achieved. *Exclusively licensed to Avco Corporation. Please direct inquiries to: Fire Protection Materials, Avco Corporation, Avco Systems Division, Lowell Industrial Park, Lowell, Massachusetts 01851. Intumescent (swelling or expanding) paints useful for fire protection have been produced. Conventional intumescent paints suffer from many disadvantages including sensitivity to water and other solvents, little resistance to scuffing and abrasion, sensitivity to thermal erosion by flames, and limited efficiency in the protection of substrates under thin steel plate or sheet. This paint overcomes these disadvantages and provides outstanding protection. The intumescent material is an aromatic nitroamino compound in the form of its sulfate, either dissolved or dispersed in a vehicle, or prepolymerized, or both. Upon heating, such a paint intumesces, chars and provides a flame resistant coating. *Exclusively licensed to Avco Corporation. Please direct inquiries to: Fire Protection Materials, Avco Corporation, Avco Systems Division, Lowell Industrial Park, Lowell, Massachusetts 01851. WH WIRE STRIPPER NASA Case No. DFRC-10111 Address inquiries to: Corresponding to U.S. Patent No. 4,117,749 Filed 8-9-76 Issued 10-3-78 An insulation stripper is described which is especially useful for shielded wire, the stripper including a first pair of jaws with blades extending substantially perpendicular to the axis of the wire, and a second pair of jaws with blades extending substantially parallel to the axis of the wire. The first pair of jaws is pressed against the wire so the blades thereof cut into the insulation, and the device is turned to form circumferential cuts in the insulation. Then the second pair of jaws is pressed against the wire so the blades thereof cut into the insulation, and the wire is moved through the device to form longitudinal cuts that permit easy removal of the insulation. Each of the blades is located within the concave face of a V-block, to center the blades on the wire and to limit the depth of blade penetration. UNSATURATING SATURABLE CORE TRANSFORMER NASA Case No. ERC-10125 Address inquiries to: Corresponding U.S. Patent No. 3,541,428 Filed 11-4-68 Issued 11-17-70 The transformer of the present invention will not saturate at any time under any conditions for any length of time. The device includes a pair of stacked, uncut, saturable magnetic cores having a plurality of windings. The cores operate in parallel and provide a means of detecting, warning and suppressing any impending saturation before saturation can occur. Many advantages are gained from the use of this transformer such as: elimination of the main apparent cause of power transistor failure in inverter circuits while enabling existing power transistors to process double or more load current, and, enabling a better utilization of existing components because it reduces the need to derate switching components to a small fraction of their current carrying capacity. Spectral analyzers and correlation computers have been used in the past to provide the most useful damping data heretofore available; however, these types of apparatus either require too much time to obtain accurate values of damping characteristics or can only be used with linear systems. The present invention relates to an automatic on-the-line instrument for measuring the damping characteristics of a structure or system during excitation by random forces or influences. The apparatus is comprised of at least two parallel sampling circuits which perform time sequential sampling operations on predetermined portions of a given input signal. After summing the outputs of the sampling circuits at output terminals, a sampling transient indicative of a point on the damping characteristic of the structure can be obtained. *Japanese manufacturing rights exclusively licensed to Japan Engineering Development Company. See page 21 for address. All other foreign patent rights available from NASA. |