A device is disclosed for controlling a rate of gas pressure increase generated by a propellant for propelling a projectile from an upstream towards a downstream end of a gun barrel. The device includes a first surface area defined by the propellant and a deterrent applied to a second surface area defined by the first surface area, the second surface area being less than the first surface area. The arrangement is such that the second surface area defines a deterrent free third surface area of the propellant. A primer is operatively disposed relative to the third surface area such that when the primer is activated, the third surface area of the propellant is ignited. The arrangement is such that firstly, while the third surface area is burning and generating gas between the upstream end of the gun barrel and the projectile, the rate of gas pressure increase begins to propel the projectile towards the downstream end of the gun barrel. Secondly, the third surface area of the propellant while burning exposes a progressively increasing surface area of the propellant for burning together with an associated increased generation of gas, the increasing surface area of the propellant defining a concave crater, the crater having a wall which progressively increases in surface area during the burning such that the rate of increase in gas pressure continues to increase for accelerating the projectile towards the downstream end of the gun barrel.

The present invention provides a gas generator, including: a cylindrical housing; an ignition device installed at a first end of the cylindrical housing, and a diffuser portion installed at a second end thereof; a flow channel forming member disposed inside the cylindrical housing and including a partition wall which separates a first chamber from a second chamber; a combustion chamber formed in the first chamber; a discharge passage formed in the second chamber; a first cylindrical space formed on the outside of the first circumferential wall and a first communication hole formed in the first circumferential wall; a second cylindrical space formed on the outside of the second circumferential wall and being in communication with the first cylindrical space, and a second communication hole formed in the second circumferential wall; a cylindrical filter disposed in the second cylindrical space; an outer diameter (d1) of the first circumferential wall, an outer diameter (d2) of the second circumferential wall and an outer diameter (d3) of the cylindrical filter satisfying relationships of d1>d2 and d1d3; and between the cylindrical filter and the inner wall surface of the cylindrical housing, the second cylindrical space facing the second communication hole via the cylindrical filter.

The present invention provides a gas generator, including: a cylindrical housing; an ignition device installed at a first end of the cylindrical housing, and a diffuser portion installed at a second end thereof; a flow channel forming member disposed inside the cylindrical housing and including a partition wall which separates a first chamber from a second chamber; a combustion chamber formed in the first chamber; a discharge passage formed in the second chamber; a first cylindrical space formed on the outside of the first circumferential wall and a first communication hole formed in the first circumferential wall; a second cylindrical space formed on the outside of the second circumferential wall and being in communication with the first cylindrical space, and a second communication hole formed in the second circumferential wall; a cylindrical filter disposed in the second cylindrical space; an outer diameter (d1) of the first circumferential wall, an outer diameter (d2) of the second circumferential wall and an outer diameter (d3) of the cylindrical filter satisfying relationships of d1>d2 and d1d3; and between the cylindrical filter and the inner wall surface of the cylindrical housing, the second cylindrical space facing the second communication hole via the cylindrical filter.

An inflator (30) comprises at least one combustion chamber (34), filled with a plurality of solid propellant pellets (10), each of the solid propellant pellets (10) including a surface having a breaking point (19) which is delimited at least by two converging surfaces (28) produced by pressing. A method of manufacturing solid propellant pellets (10), includes the steps of providing a solid propellant (12), pressing the solid propellant (12) into a pellet blank (16), the pellet blank (16) having at least one predetermined breaking point (18) which divides the pellet blank (16) into at least two subareas (20), and breaking the pellet blank (16) along the at least one predetermined breaking point (18), wherein each of the at least two subareas (20) forms a solid propellant pellet (10).

An inflator (30) comprises at least one combustion chamber (34), filled with a plurality of solid propellant pellets (10), each of the solid propellant pellets (10) including a surface having a breaking point (19) which is delimited at least by two converging surfaces (28) produced by pressing. A method of manufacturing solid propellant pellets (10), includes the steps of providing a solid propellant (12), pressing the solid propellant (12) into a pellet blank (16), the pellet blank (16) having at least one predetermined breaking point (18) which divides the pellet blank (16) into at least two subareas (20), and breaking the pellet blank (16) along the at least one predetermined breaking point (18), wherein each of the at least two subareas (20) forms a solid propellant pellet (10).

The application relates to a Ramjet solid fuel having an ignition temperature of less than 400 C., the fuel comprising a bis-(ethylene oxy) methane polysulfide polymer (BMPP) and hydroxyl-terminated polybutadiene (HTPB), the copolymer having a BMPP/HTPB weight ratio of from 1/3 to 3/1; and the fuel comprising at least 85 weight % copolymer. The BMPP comprises from 5 to 8 weight percent mercaptan. Furthermore, the BMPP is selected from
HS(RSS).sub.aCH.sub.2CH((SSR).sub.cCSH)CH.sub.2(SSR).sub.bSHa) where R(CH.sub.2).sub.2OCH.sub.2O(CH.sub.2).sub.2 and a+b+c<7; and
H(SC.sub.2H.sub.4OCH.sub.2OC.sub.2H4S).sub.nH where n=7.b)

The application relates to a Ramjet solid fuel having an ignition temperature of less than 400 C., the fuel comprising a bis-(ethylene oxy) methane polysulfide polymer (BMPP) and hydroxyl-terminated polybutadiene (HTPB), the copolymer having a BMPP/HTPB weight ratio of from 1/3 to 3/1; and the fuel comprising at least 85 weight % copolymer. The BMPP comprises from 5 to 8 weight percent mercaptan. Furthermore, the BMPP is selected from
HS(RSS).sub.aCH.sub.2CH((SSR).sub.cCSH)CH.sub.2(SSR).sub.bSHa) where R(CH.sub.2).sub.2OCH.sub.2O(CH.sub.2).sub.2 and a+b+c<7; and
H(SC.sub.2H.sub.4OCH.sub.2OC.sub.2H4S).sub.nH where n=7.b)

A gas generator including, a housing provided with a gas discharge port, an ignition chamber provided on a side of a first end portion of the cylindrical housing and including an igniter, a combustion chamber disposed within the housing and containing therein a molded article of a gas generating agent, a rupturable closing member partitioning the combustion chamber from the ignition chamber and including therein a rupturable portion partially ruptured upon an actuation of the gas generator, a molded article of a transfer charge contained in the ignition chamber, an inner tube disposed in the combustion chamber and extending from the closing member toward the gas discharge port and defining, in an outside thereof, a space that contains the molded article of the gas generating agent, the inner tube including therein a hollow space and having a peripheral wall provided with a plurality of through holes, the inner tube including a first open end and communicating the hollow space with the ignition chamber so as to transfer the molded articles of the transfer charge in a burning state toward the second end portion in the inner tube when the rupturable portion is ruptured.

A device is disclosed for controlling a rate of gas pressure increase generated by a propellant for propelling a projectile from an upstream towards a downstream end of a gun barrel. The device includes a first surface area defined by the propellant and a deterrent applied to a second surface area defined by the first surface area, the second surface area being less than the first surface area. The arrangement is such that the second surface area defines a deterrent free third surface area of the propellant. A primer is operatively disposed relative to the third surface area such that when the primer is activated, the third surface area of the propellant is ignited. The arrangement is such that firstly, while the third surface area is burning and generating gas between the upstream end of the gun barrel and the projectile, the rate of gas pressure increase begins to propel the projectile towards the downstream end of the gun barrel. Secondly, the third surface area of the propellant while burning exposes a progressively increasing surface area of the propellant for burning together with an associated increased generation of gas, the increasing surface area of the propellant defining a concave crater, the crater having a wall which progressively increases in surface area during the burning such that the rate of increase in gas pressure continues to increase for accelerating the projectile towards the downstream end of the gun barrel.

A device is disclosed for controlling a rate of gas pressure increase generated by a propellant for propelling a projectile from an upstream towards a downstream end of a gun barrel. The device includes a first surface area defined by the propellant and a deterrent applied to a second surface area defined by the first surface area, the second surface area being less than the first surface area. The arrangement is such that the second surface area defines a deterrent free third surface area of the propellant. A primer is operatively disposed relative to the third surface area such that when the primer is activated, the third surface area of the propellant is ignited. The arrangement is such that firstly, while the third surface area is burning and generating gas between the upstream end of the gun barrel and the projectile, the rate of gas pressure increase begins to propel the projectile towards the downstream end of the gun barrel. Secondly, the third surface area of the propellant while burning exposes a progressively increasing surface area of the propellant for burning together with an associated increased generation of gas, the increasing surface area of the propellant defining a concave crater, the crater having a wall which progressively increases in surface area during the burning such that the rate of increase in gas pressure continues to increase for accelerating the projectile towards the downstream end of the gun barrel.