Methods, Systems and Devices to Shape a Pressure*Time Wave Applied to a Projectile to Modulate its Acceleration and Velocity and its Launcher/Gun's Recoil and Peak Pressure Utilizing Interior Ballistic Volume Control

Abstract

Methods, systems, and devices to shape a pressure*time wave applied to sniper and dangerous game rifle projectiles whereby an ammunition shell casing's volume, at release of the projectile from the casing, and rifle system impedance (Z) in conjunction with the amount of propellant are modulated to beneficially shape the wave applied to the projectile's base, and by Newton's 2.sup.nd law the projectile's applied acceleration*time impulse wave, to reliably reduce the velocity of a sniper or dangerous game rifle's ammunition to a sub-Mach 1 level, preserve the projectile momentum, maintain the rifle's automatic shell casing ejection and new shell casing/projectile re-load action and maintain a projectile and rifle operation within their material's strength limits. These tools are further applied to simulate severe g acceleration environments for commercial and military weapon sub-system component's non-destructive testing and certification that are carried in a projectile and applicable to any existing propellant launcher/gun system.

Claims

1. A pressure*time wave, where the symbol * indicates a running continuum integral as an off-spring projectile traverses the barrel/guide of a rifle, re-shaping method to reliably obtain a sub-Mach 1 rifle barrel/guide exit velocity and preserve automatic operation of standard automatic rifles (launcher/guns) used as sniper rifles and dangerous game rifles and for stabilization of the off-spring projectile's transit to a sniper's target or dangerous game target thereby maintaining the rifle operator's aim point, where Mach 1 is the speed of sound in the atmosphere within the confines of a rifle's barrel/guide, or substantially 1100 feet/second, in which an off-spring projectile is launched by internal volume control and further applied to the base of a sniper or dangerous game rifle's off-spring projectile whereby the off-spring projectile is attached to an accompanying parent-case containing solid propellant grains by modifying the rifle system's internal volume at initial propellant ignition and thereby its impedance Z=F/V.sub.f=J where (Z) is the rifle system's impedance in the English engineering units of g*#*seconds/foot and J in equal units is the per unit distance impulse delivered to an off-spring projectile, and further one g is the unitless acceleration due to gravity at the Earth's surface and is the standard unitless gravity symbol g, # is the symbol for the physical weight of an off-spring projectile, F is the delivered force in units of g*# to the base of the off-spring projectile and V.sub.f is the final velocity of the off-spring projectile at the rifle barrel/guide's exit in g*seconds and further applied at the rifle system's inflection point located at the attainment of the rifle system's peak pressure occurring at the end of the time consumed by initial momentum transfer from the parent-case propellant ignition gases to off-spring projectile's base and during first release of the off-spring projectile from an attached off-spring projectile's parent-case and rise to peak pressure and peak g acceleration on the off-spring projectile's base after ignition of the rifle's propellant grains and further during the initial movement of the off-spring projectile resulting in a change in the parent-case volume, to beneficially modify the off-spring projectile's final velocity V.sub.f at rifle barrel/guide exit and applied peak acceleration of a rifle system and peak internal pressure of the rifle system, and preserving sufficient momentum to operate the rifle's automatic ejection of the off-spring projectile's spent parent-case and reloading of a new combination parent-case and off-spring projectile, said method comprising the steps of: Increasing the material density of the off-spring projectile thereby increasing its mass properties and lowering the system impedance (Z) to provide resistance to movement at the rifle system's inflection point thereby reducing the initial parent-case volume and occurring at first release of the off-spring projectile from the parent-case and at the system inflection point located at the first release point of the off-spring projectile from its parent-case; Reducing the amount of propellant grains in the parent-case by an amount that will preserve off-spring projectile momentum thereby satisfying the momentum equation M.sub.NV.sub.FN=M.sub.OV.sub.FO, where x indicates multiplication, thereby keeping the rifle's operating conditions within the limits of the rifle's material properties and retaining proper ejection of the parent-case and re-loading of a new-parent-case with off-spring projectile and where M.sub.N is the new value of the off-spring projectile mass, V.sub.FN is the desired new final velocity V.sub.f of the off-spring projectile at the off-spring projectile's base rifle barrel/guide exit, M.sub.O is the former value of the off-spring projectile mass and V.sub.FO is the former value of the velocity V.sub.f of the off-spring projectile at off-spring projectile base rifle barrel/guide exit.

2. A method of claim 1 for simulating severe g acceleration environments for commercial or military weapon sub-system component's non-destructive testing and certification and applicable to the full suite of existing propellant launcher/guns and maintaining the launcher/gun system operation within the launcher/gun's material property limits and operating parameters by volume and off-spring projectile mass properties control and thereby system impedance (Z) control within any launcher/gun system to tailor the pressure*time wave and therefore the per distance unit impulse (J) in the equation Z=F/V.sub.f=J applied to an off-spring projectile containing components to be tested and certified and the resulting g acceleration*time impulse wave to the desired value for application to military or commercial components during launch from a launcher/gun system containing an off-spring projectile with the components to be tested or certified therein for the purposes of testing the g tolerance of the components and/or certification of the components, said methods comprising the steps of: Defining the required g amplitude and military or commercial component exposure time in seconds to be applied to the components to be tested and dividing this value of g*time, where the symbol * indicates a continuum running integral as an off spring projectile traverses the barrel/guide, by the length of the barrel/guide thereby forming the value of the system impedance (Z) required for the equation Z=F/V.sub.f=J, where (Z)=(J) is the system impedance and per distance unit impulse respectively in English engineering units of g*#*seconds/foot, g*# is the delivered force (F) to an off-spring projectile and # is the symbol for the physical weight of a bullet in pounds, V.sub.f is the final velocity of an off-spring projectile at the launcher/gun barrel/guide's exit in feet/second and one g is the acceleration due to gravity at the Earth's surface and is the standard unitless gravity symbol g: Modifying the off-spring projectile mass thereby the off-spring projectile's mass properties and parent case initial volume and final velocity V.sub.f at off-spring projectile base barrel/guide exit to obtain the desired characteristic impedance (Z) in the equation Z=F/V.sub.f=J and reducing the amount of propellant in the launcher/gun system by an amount that will preserve off-spring projectile momentum that will satisfy the momentum equation M.sub.NV.sub.FN=M.sub.OV.sub.FO to retain the gun's operating conditions within the limits of the gun's material properties, where M.sub.N and V.sub.FN are the new values of the off-spring projectile mass and final velocity of the off-spring projectile at off-spring projectile base barrel/guide exit that yield the desired system impedance (Z) and M.sub.O and V.sub.FO are the former values of an off-spring projectile's mass and velocity at off-spring projectile base barrel/guide exit that were unequivocally demonstrated to maintain the gun's operating conditions within the limits of the gun's material properties and operating parameters.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0010] The embodiment set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following brief description of the illustrative embodiments can be understood when read in conjunction with the following drawings.

[0011] FIG. 1 schematically depicts a launcher/gun system and parent-case and off-spring projectile and the dynamic formation of a new volume within the parent-case chamber of a launcher/gun utilizing a formable material insert and dynamically hydroforming a new volume by operating the material in its forming region during propellant burn and rise to peak pressure within the parent-case and/or an a priori delta () change in the mass properties of the off-spring projectile to effect a () (Z) impedance modulation and therefore a () (J) per unit distance impulse modulation.

[0012] FIG. 2 schematically depicts on the top schematic the creation of a virtual mass and on the bottom an a priori modulation of the off-spring projectile mass properties and/or geometry to modulate system impedance (Z) and volume during dynamic propellant burn at the system inflection point negating any large initial volume expansion due to the barrel/guide piston effect and modulate the final velocity of the off-spring projectile and the recoil of a launcher/gun system.

[0013] FIG. 3 graphically depicts on the left graph the percent applied off-spring projectile base pressure versus the percent of off-spring projectile base pressure wave application time and on the right graph the percent of applied off-spring projectile base pressure versus percent of off-spring projectile barrel/guide travel during release from the parent-case and rise to the peak pressure and further identifies the system inflection point for the launcher/gun case.

[0014] FIG. 4 graphically depicts in the percent of pressure*time wave application time and per cent of peak applied pressure the applied off-spring projectile's base pressure*time wave of a parent-case chamber before and after dynamic volume control by hydro-forming a new volume within the parent-case and before and after volume reductions due to a priori mass property or geometry changes to the off-spring projectile thereby in the case shown increasing a launcher/gun system impedance (Z).

[0015] FIG. 5 graphically depicts, in percent of full applied pressure, the pressure*time wave applied to the base of an off-spring projectile by the formation of new off-spring projectile virtual mass properties by creation of these new properties by the formation of a back pressure to reduce the final velocity by reducing the area under the pressure*time curve applied to the off-spring projectile base, thereby reducing the area under the acceleration*time curve applied to the off-spring projectile in percent of wave application time.

DETAILED DESCRIPTION OF DRAWINGS

[0016] FIG. 1 depicts the forward part of a launcher/gun system 100 showing the off-spring projectile 140, parent case 150 and barrel/guide 180 with a malleable formable material insert 120 surrounded by air whose purpose is to dynamically create a new volume during rise to peak pressure at the system inflection point 152, the expansion of 120 to a new 122 geometry in the space previously occupied by air, the propellant grains 130 within the parent-case 150, the propellant changed to a gas 132 by ignition of the propellant 130 by the parent-case primer 160, the off-spring projectile 140 with a new system impedance (Z) and the barrel/guide 180.

[0017] The malleable formable insert 120 fully captures the propellant grains 130 before ignition by primer 160. Fully capturing the propellant grains 130 before ignition prohibits the propellant grains 130 from repositioning in random patterns during handling and firing of the combination parent-case 150/off-spring projectile 140. This prevents variances in the barrel/guide 180 exit velocity V.sub.f of the off-spring projectile 140 and maintains reliable ignition of the propellant 130 from shot to shot.

[0018] The insert material 120 is selected to be formable during propellant burn, that is, the material operates within its plastic regime called the hydroforming regime and defined on FIG. 1 as the forming region dotted horizontal line on the material's stress versus strain curve. During ignition of the primer 160 and burn of the solid propellant 130, changing 130 into a gas 132, the insert 122 is formed on the walls of the parent-case thereby dynamically increasing parent-case 150 volume at the system inflection point 152. This volume expansion modulates launcher/gun system parent-case 150 peak pressure, system impedance (Z), off-spring projectile velocity V.sub.f, launcher/gun recoil and applied base off-spring projectile 140 applied pressure and acceleration.

[0019] FIG. 2 top depicts the creation of a virtual mass constituting a back pressure or null force to dynamically change the mass properties of the off-spring projectile 140 during release of the off-spring projectile 140 from the parent-case 150 at the inflection point 152. The off-spring projectile 140, normally crimped to a parent-case with only a minimal resisting back pressure force, is in order of joint 170 shear strength resistances from high to low; brazed, soldered, glued or threaded to the parent-case for the purpose of providing a resistance to movement and keeping the volume of the parent-case 150 constant until joint 170's shear resistance strength is overcome; and then permitting movement down the barrel/guide 180 of the off-spring projectile. This has the effect of nulling that portion of the pressure*time curve until the pressure rises to a value that it overcomes the shear strength of the joint 170 and the off-spring projectile 140 begins movement down the barrel/guide 180 and opens additional volume. FIG. 2 bottom shows the option of a () mass property modulation of off-spring projectile 140 linearly producing a (Z) system impedance thereby reducing or increasing the percentage of barrel/guide 180 travel during rise to peak pressure thereby reducing or increasing the parent-case 150 volume at the inflection point 152 during release of the off-spring projectile 140 from the parent-case and thereby modulating system impedance (Z).

[0020] The FIG. 3 left graph is the normalized to 100% peak pressure of the pressure*time wave versus normalized to 100% percent of pressure*time wave application time of a common fixed volume and fixed system impedance parent-case 150 pressure chamber with no new volume formed dynamically by a formable material insert 120 or adjustments to the off-spring projectile 140 mass properties either virtually or physically. The right graph is the normalized to 100% off-spring projectile 140 peak pressure obtained versus normalized to 100% barrel/guide 180 off-spring projectile 140 base travel for this common case. In the event the off-spring projectile 140 piston effect of opening a new volume is substantially 6% of the off-spring projectile 140 travel as the volume remains near constant during momentum transfer from propellant gas 132 to off-spring projectile 140 and reaching maximum pressure at the inflection point 152 within the parent-case 150. This graph identifies the common case system inflection point 152 as a function of barrel/guide 180 off-spring projectile 140 travel at 100% peak applied base off-spring projectile 140 pressure.

[0021] FIG. 4 depicts the results of the real-time modulation of the parent-case 150 volume and/or an a priori physical change to the mass properties and/or geometry of the off-spring projectile 140 in normalized percent of parent-case peak pressure applied to the off-spring projectile 140 versus percent of time the pressure*time wave is applied to the off-spring projectile 140 and thereby a modulation of the system impedance (Z). The solid line is the pressure*time wave curve applied to the off-spring projectile 140 without dynamic volume expansion within the parent-case 150 or change in off-spring projectile 140 mass properties; the dotted line shows the pressure*time results due to system impedance (Z) modulation by dynamic hydroforming of a new volume within the parent-case 150 or dynamic forming of a new volume by inhibiting off-spring projectile 140 movement during release from the parent case 150 due to changes to the off spring projectile 140 mass properties or geometry. These graphs reflect a change to a higher value of system impedance (Z). The graphs would be reversed for a lower value of system impedance (Z),

[0022] FIG. 5 depicts normalized percentage results for an 80 percent pressure level that overcomes the shear strength of joint 170. The hatched area on the left graph is the area that is lost as a result of the back pressure formed by the joint 170 which nulls a portion of the acceleration*time wave area application to the off-spring projectile 140. The graph to the right is the resulting pressure*time wave applied to the off-spring projectile 140 that modulates velocity and recoil in this illustration to a higher value of system impedance (Z) due to the formation of a virtual mass, that is, back pressure.