Abstract: Propellant grain consisting essentially of:A. from about 50% to about 75% by weight of an oxidizer consisting essentially of ammonium nitrate;B. from about 1% to about 20% by weight of a cured polymeric binder;C. from 0% to about 30% by weight of a nitrate ester plasticizer;D. from about 3.5% to about 8% by weight of boron in free elemental form; andE. from 0% to about 3% by weight of aluminum metal.The grain has a pressure exponent not exceeding about 0.30 at a combustion pressure between about 2500 and about 7000 pounds per square inch (between about 1700 and about 4800 N/cm.sup.2). Also, an uncured pourable slurry having the formula stated above, except that the binder is uncured. Also, a method for forming a propellant grain having the formula stated above, comprising the steps of providing the uncured pourable slurry defined above, pouring the slurry into a casing, and curing the slurry in situ to form a cured propellant grain having a pressure exponent not exceeding about 0.
Abstract: A process and equipment for making seamless composite tubes. Composite material is applied on a mandrel which includes an inflatable bladder and inserted in a single piece mold. The bladder is pressurized for pressing the composite material against the mold wall for molding and curing thereof. In order to prevent seizing of the tube by the mold and thus allow easy removal of the cured tube, the mold is composed of a composite of resin impregnated carbon fiber material wherein the carbon fiber material has a negative coefficient of thermal expansion along the length thereof and is oriented at an angle of between about 15 and 40 degrees relative to a radial plane of the mold. In order to eliminate the use of inefficient and inconvenient cure ovens, a heat generating element is disposed internally of the mandrel for curing of the composite material.
Abstract: Solid propellants in which the oxidizer is a perchlorate are improved by the inclusion of diaminoglyoxime or diaminofurazan in the propellant compositions.
Type:
Grant
Filed:
June 14, 1990
Date of Patent:
December 10, 1991
Assignee:
Thiokol Corporation
Inventors:
Rodney L. Willer, Minn-Shong Chi, Robert Gleeson, John C. Hill
Abstract: A multi-pulse or multi-stage canister loaded solid propellant rocket motor. The canisters are prepared separately and loaded with solid propellant whereby the scrape rate may be reduced after which they are installed in a monolithic case which affords stiffness continuity over the length of the rocket motor to prevent guidance system upsetting free play. In order to reduce the complexity of installation of the membrane seal assembly for each pulse, the bulkhead therefor is manufactured integral with the case of the respective canister and becomes the forward closure thereof. For the multi-stage rocket motor, the monolithic case may be stepped and tapered, and the stages severable therefrom as they burn out by primer cord.
Abstract: An igniter which is removably insertable in a rocket motor nozzle throat. The igniter includes a sleeve which has a body portion and a plurality of flexible and frangible tab members extending axially from one end of the body portion and spaced circumferentially thereabout and which have first portions which in combination define a diameter which is greater than the nozzle throat diameter. The frangible portions of the tab members in combination define an outer diameter which is substantially equal to the throat diameter. The body portion of the sleeve has a diameter which is greater than the throat diameter. The sleeve is insertable in the nozzle throat by flexing the tab members so that the first portions clear the throat and so that the frangible portions of the tab members are disposed in the throat. The tab members, in combination, have an inner diameter which is substantially equal to the inner diameter of the body portion of the sleeve.
Type:
Grant
Filed:
August 4, 1989
Date of Patent:
November 5, 1991
Assignee:
Thiokol Corporation
Inventors:
Robert I. Myers, Bryce D. Brubaker, Robert E. Overall
Abstract: A rapid burning propellant charge for applications including igniters, launch eject motors, and gas generators for automobile air bags. The propellant charge comprises a reticulated substrate having a quantity of interconnected ligaments and a coating of solid propellant material on the ligaments. In order to provide a large amount of surface area for a fast burn time, interstices are between coated ligaments to define propellant surface area for combustion. In applications where minimum smoke is desired, the reticulated substrate is preferably composed of carbon, graphite, or a non-combustible material, and the solid propellant material is preferably a minimum smoke type.
Abstract: Substituting non-metallic screw elements for the previously used metal screw elements in twin-screw extruders reduces the hazards inherent in the extrusion of highly energetic materials which exhibit impact and friction sensitivity when processed in twin screw extruders with metal screw elements.
Abstract: A rocket motor or other gas generator the case of which is ventable at a predetermined temperature substantially greater than the ambient temperature range for storage and operation thereof and substantially less than the auto-ignition temperature of gas generant material contained therein so as to prevent catastrophic propulsion or burst in case of fire. The venting is provided by memory metal members which are interleaved between plies of matrix-impregnated fibrous material in the case and which have a transformation temperature which is substantially higher than the ambient temperature range and substantially lower than the auto-ignition temperature and characterized by a change in shape when heated to a temperature above the transformation temperature.
Abstract: A rocket motor having case segments which are attached together. A retaining member extends circumferentially thereabout to maintain attachment of the segments together. The retaining member is characterized by sensitivity to a predetermined temperature greater than ambient temperature and less than the ignition temperature of propellant material in the rocket motor to lose strength whereby the retaining member is released and the rocket motor may safely be rendered non-propulsive during a hazard such as a fuel fire or slow cook-off.
Type:
Grant
Filed:
November 27, 1989
Date of Patent:
September 3, 1991
Assignee:
Thiokol Corporation
Inventors:
R. Hill English, Jr., Hermann L. Miskelly, Jr.
Abstract: Thermoplastic matrix composite cylinders, pipes, and other hollow bodies are formed by a winding technique using thermoplastic filaments. The filaments are fed from a vertically moving winding head onto the surface of a rotating mandrel. The filaments are preheated to soften them and then pass beneath a heated compaction roller bearing against the mandrel. The compaction roller is castered so as to follow a helical path. Several plies of the thermoplastic material may be laid down in this fashion, the surface of each prior ply being heated so that the layers fuse properly. When cooled to below its solidification temperature, the formed object is removed from the mandrel.
Abstract: The particle size of energetic explosive materials is reduced by slurrying the particulate explosive materials in an inert liquid such as water or an aqueous solution, and subjecting the slurry to intense acoustic cavitation from an ultrasonic generator for a short time. The particulate explosive materials are rapidly ground to a small particle size while minimizing the danger of detonation.
Abstract: A radiation gathering reflector and a method of making a radiation gathering reflector. Resin impregnated fibrous material is wound onto a mandrel which has a pair of opposing surfaces of revolution each of which has a shape corresponding to a predetermined shape of the inner reflector surface, and the resin is allowed to polymerize to form a composite which includes two integrally connected structural support members. An equatorial cut is formed in the composite to separate the support members from each other and from the mandrel. Then, a reflective surface is formed on the inner surface of at least one of the separated support members for gathering radiation. Alternatively, the reflective surface is formed on the surface of the mandrel and the resin impregnated fibrous material is wound onto the reflective surface and allowed to polymerize to form the composite.
Abstract: Improved bonding of hydroxyl-terminated polybutadiene based propellant grains to rocket motor liners and liners which are ultraviolet light radiation curable are provided by employing an acrylated polymer and an [[[(isocyanatoorgano)amino]carbonyl]oxy] alkyl propenoate in the liner composition.
Abstract: Propellants have high energy particulates dispersed in a binder system based upon thermoplastic elastomeric ionomers. In addition to the ionomer, the binder system has an ionolyzer which melts at processing temperatures and facilitates relative movement of ionic segments of the ionomer, plus a plasticizer for hydrophobic, amorphous segments of the ionomer.
Abstract: A rapid burning propellant charge for applications including igniters, launch eject motor, and gas generators for automobile air bags. The propellant charge comprises a reticulated substrate having a quantity of interconnected ligaments and a coating of solid propellant material on the ligaments. In order to provide a large amount of surface area for a fast burn time, interstices are between coated ligaments to define propellant surface area for combustion. In applications where minimum smoke is desired, the reticulated substrate is preferably composed of carbon, graphite, or a non-combustible material, and the solid propellant material is preferably a minimum smoke type.
Abstract: Occluded acidity in particulate explosives is removed by slurrying the particles in an inert liquid and subjecting the slurry to wet-grinding. The inert liquid may include an alkaline salt at or near saturation. Separation of the ground explosive particles from the liquid phase results in a ground explosive material with much reduced acidity.
Abstract: The moisture or water vapor barrier protection of a composite pressure vessel suitable for use as a composite cased solid propellant rocket motor is improved by immersing the pressure vessel, during pressure testing thereof, in a curable liquid polymer solution, optionally containing electrically conductive material such as metallic flakes or powder, so that the solution may flow into open voids, cracks or fractures in the pressure vessel and subsequently curing the curable liquid polymer in said voids, cracks or fractures.
Type:
Grant
Filed:
December 11, 1989
Date of Patent:
June 4, 1991
Assignee:
Thiokol Corporation
Inventors:
Robert E. Black, Jr., Don C. Carson, Frederick W. Van Name
Abstract: Chemorheologically viscosity tailored matrix resin formulation for use in forming prepregs and filament wound composite articles and having a specified viscosity profile comprising a curable matrix resin and an effective amount of a reactive resin curing agent reactive at room temperature and a latent resin curing agent substantially non-reactive at room temperature but activated upon heating or radiation such that the matrix resin formulation is adapted upon formulation to have a viscosity sufficiently low enough to enable the matrix resin to impregnate a filament or fiber at room temperature without the necessity for the application of heat or solvent and which, upon standing at room temperature after impregnation into the fiber or filament to form a prepreg composition, rises in viscosity to a viscosity level sufficiently high to prevent substantially any bleed of the matrix resin from winding tension upon spooling of the prepreg yet of sufficiently low enough viscosity to allow the prepreg to tack and dra
Abstract: A radial pulse rocket motor having a nozzle at the aft end includes longitudinally spaced hollow boost and sustain propellant grains in the combustion chamber thereof with an elongated tubular thermal barrier covering substantially the whole of the interior surface of the sustain grain to enable the production of separate boost and sustain pulses. At the forward end of the motor, mounted within a reentrant motor bulkhead position, is a multiple pulse arm-fire device which, when commanded, produces an igniting signal that is transmitted to a boost igniter for igniting the boost grain and a subsequent igniting signal that is transmitted to a sustain igniter for igniting the sustain grain. The sustain igniter is positioned in surrounding relation to the motor forward bulkhead reentrant portion, the multiple pulse arm-fire device, and the forward end of the tubular barrier, and comprises a consumable, molded, polyurethane case having two interlocking tubes with a thin 0.10 inch (2.5 mm.