Projectile stabilization system

Claim 1

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a top side of the fixed fin; and a plurality of folding fins each pivotably accommodatable in the pocket of a fixed fin, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore, each of said folding fins being adapted to unfold in a sense opposed to the flight direction of said projectile, wherein each of the folding fin is adapted to unfold as a function of a moment applied to the folding fin, the moment M' being definable as M'=Δp·A·l wherein Δp=1/2ρ g (V g -V p ) 2 , ρ g is the average density of the propellant gas, V g is the gas velocity after exiting the bore, V p is the projectile velocity after exiting the bore, A is the area of the top surface of the folding fin and 1 is the distance between a pivot pin about which the folding fin pivots and the fin's center of gravity.

Claim 2

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a top side of the fixed fin; and a plurality of folding fins each pivotably accommodatable in the pocket of a fixed fin, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore, each of said folding fins being adapted to unfold in a sense opposed to the flight direction of said projectile, wherein each of the folding fin is adapted to unfold as a function of a moment applied to the folding fin, the moment M' being definable as M'=Δp·A·l wherein Δp=1/2ρ g (V g -V p ) 2 , ρ g is the average density of the propellant gas, V g is the gas velocity after exiting the bore, V p is the projectile velocity after exiting the bore, A is the area of the top surface of the folding fin and 1 is the distance between a pivot pin about which the folding fin pivots and the fin's center of gravity.

Claim 3

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a top side of the fixed fin; and a plurality of folding fins each pivotably accommodatable in the pocket of a fixed fin, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore, each of said folding fins being adapted to unfold in a sense opposed to the flight direction of said projectile, wherein a center of gravity of each folding fin is located with respect to a pivoting axis, so that as a result of acceleration setback a moment is applied to the folding fin to pivot it in a direction to retain it within the pocket, and wherein each folding fin is adapted to unfold as a function of a moment applied to the folding fin, the moment M' being definable as M'=Δp·A·l where Δp=1/2ρ g (V g -V p ) 2 , wherein ρ g is the average density of the propellant gas, V g is the gas velocity upon exiting the bore, V p is the projectile velocity upon exiting the bore, A is the area of the top surface of the folding fin and 1 is the distance between a pivot point about which the fin pivots and its center of gravity.

Claim 4

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a top side of the fixed fin; and a plurality of folding fins each pivotably accommodatable in the pocket of a fixed fin, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore, each of said folding fins being adapted to unfold in a sense opposed to the flight direction of said projectile, wherein a center of gravity of each folding fin is located with respect to a pivoting axis, so that as a result of acceleration setback a moment is applied to the folding fin to pivot it in a direction to retain it within the pocket, and wherein each folding fin is adapted to unfold as a function of a moment applied to the folding fin, the moment M' being definable as M'=Δp·A·l where Δp=1/2ρ g (V g -V p ) 2 , wherein ρ g is the average density of the propellant gas, V g is the gas velocity upon exiting the bore, V p is the projectile velocity upon exiting the bore, A is the area of the top surface of the folding fin and 1 is the distance between a pivot point about which the fin pivots and its center of gravity.

Claim 5

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a top side of the fixed fin; a plurality of folding fins each pivotably mounted in the pocket of a fixed fin about a pivot axis, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore; and wherein each of said folding fins has a center of gravity located forwardly of said pivot axis and spaced therefrom by a distance l and a top surface having an area A, said distance l and area A having values such that a moment M' acting on said folding fin after the projectile exits the bore and defined by M'=Δp·A·l, wherein Δp=1/2ρ g (V g -V p ) 2 , ρ g is the average density of the propellant gas, V g is the gas velocity after exiting the bore, and V p is the projectile velocity after exiting the bore, is sufficient to pivot said folding fin out of said pocket.

Claim 6

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a top side of the fixed fin; a plurality of folding fins each pivotably mounted in the pocket of a fixed fin about a pivot axis, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore; and wherein each of said folding fins has a center of gravity located forwardly of said pivot axis and spaced therefrom by a distance l and a top surface having an area A, said distance l and area A having values such that a moment M' acting on said folding fin after the projectile exits the bore and defined by M'=Δp·A·l, wherein Δp=1/2ρ g (V g -V p ) 2 , ρ g is the average density of the propellant gas, V g is the gas velocity after exiting the bore, and V p is the projectile velocity after exiting the bore, is sufficient to pivot said folding fin out of said pocket.

Claim 7

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a topside of the fixed fin; and a plurality of folding fins each pivotably accommodatable in the pocket of a fixed fin, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore, each of said folding fins being adapted to unfold in a sense opposed to the flight direction of said projectile, wherein each folding fin unfolds as a function of a moment M' definable as M'=Δp·A·l where Δp=1/2ρ g (V g -V p ) 2 , where ρ g is the average density of the propellant gas, V g is the gas velocity after exiting the bore, V p is the projectile velocity upon exiting the bore, A is the area of the top surface of the folding fin and l is the distance between a pivot point about which the fin pivots and its center of gravity.

Claim 8

A system for stabilizing a projectile which is propellable by gas pressure out of a bore of a firing device toward a target, the system comprising: a plurality of fixed fins arranged aft of the projectile and extending outwardly from a core, each fixed fin defining a pocket which extends inwardly from a topside of the fixed fin; and a plurality of folding fins each pivotably accommodatable in the pocket of a fixed fin, with each folding fin being totally within a pocket when in the folded state and being pivotable to assume an unfolded state where a substantial portion of the folding fin is out of said pocket when said projectile and system exit the device's bore, each of said folding fins being adapted to unfold in a sense opposed to the flight direction of said projectile, wherein each folding fin unfolds as a function of a moment M' definable as M'=Δp·A·l where Δp=1/2ρ g (V g -V p ) 2 , where ρ g is the average density of the propellant gas, V g is the gas velocity after exiting the bore, V p is the projectile velocity upon exiting the bore, A is the area of the top surface of the folding fin and l is the distance between a pivot point about which the fin pivots and its center of gravity.