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US3678745A Expired / Lapsed US ⏱️ 0.0 years remaining

Ballistic compression decelerator

Assignee: McDonnell Douglas Corp
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Filing: 1970-11-12
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Granted: 1972-07-25
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Expires: 1990-11-12
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Abstract

Abstract Projectiles are recovered from free-flight for analysis of flight effects on the projectile. Recovery is accomplished by converting kinetic energy into controlled heat of compression which is dissipated in several stages. Shock compression is used during supersonic velocities of the projectile and adiabatic compression is used during sonic and subsonic velocities. Decelerator tubes having diaphragms within them are precharged to high pressure in front of the projectile to minimize the decelerating distance. The final diaphragm may or may not break depending upon the adiabatic pressure buildup.

Inventors

  • 👤 Robert N Teng

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 07:52
CPC Classifications
F; F41; F41J; F41J13/00

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 97 words
In combination with a ballistic range wherein a projectile is accelerated to high velocities, a ballistic compression decelerator for stopping said projectile without damage thereto, said decelerator comprising decelerator tubes through which said projectile passes, said tubes having diaphragms over the ends thereof to cause gas in front of said advancing projectile to compress, said diaphragms being of a strength to cause a buildup of pressure in front of said projectile yet rupture before being pierced by said projectile, whereby said projectile is successively decelerated as it passes through successive tubes until said projectile is completely decelerated.
Claim 2
Dependent Claim 97 words
In combination with a ballistic range wherein a projectile is accelerated to high velocities, a ballistic compression decelerator for stopping said projectile without damage thereto, said decelerator comprising decelerator tubes through which said projectile passes, said tubes having diaphragms over the ends thereof to cause gas in front of said advancing projectile to compress, said diaphragms being of a strength to cause a buildup of pressure in front of said projectile yet rupture before being pierced by said projectile, whereby said projectile is successively decelerated as it passes through successive tubes until said projectile is completely decelerated.
Claim 3
Dependent Claim 26 words
A ballistic compression decelerator as in claim 1 wherein said diaphragms are made of polyethylene terephthalate and have a thickness on the order of 0.005 inches.
Claim 4
Dependent Claim 25 words
A ballistic compression decelerator as in claim 1 wherein five tubes approximately 20 feet long are used, each having a diaphragm over the end thereof.
Claim 5
Dependent Claim 81 words
In combination with a ballistic range wherein projectiles are accelerated to high velocities through an environment test chamber, a ballistic compression decelerator comprising a series of decelerator tubes through which said projectile passes and through which a shock wave proceeds the advancing projectile, said tubes having diaphragms over the ends thereof to cause air in front of said advancing projectile to compress, some of said decelerator tubes being precharged to a higher pressure to reduce the decelerating distance of said projectile.
Claim 6
Dependent Claim 81 words
In combination with a ballistic range wherein projectiles are accelerated to high velocities through an environment test chamber, a ballistic compression decelerator comprising a series of decelerator tubes through which said projectile passes and through which a shock wave proceeds the advancing projectile, said tubes having diaphragms over the ends thereof to cause air in front of said advancing projectile to compress, some of said decelerator tubes being precharged to a higher pressure to reduce the decelerating distance of said projectile.
Claim 7
Dependent Claim 174 words
In combination with a ballistic range wherein a projectile may be accelerated to high velocities through an environment test chamber, a ballistic compression decelerator including a low pressure shock decelerator tube through which a supersonic shock wave proceeds the advancing projectile, said tube having a diaphragm over the end thereof to cause air in front of said advancing projectile to compress, said ballistic compression decelerator including a high pressure shock decelerator tube axially aligned with said low pressure shock decelerator tube having a diaphragm over the end thereof and precharged to a higher pressure than in said low pressure shock decelerator tube to reduce the velocity of said projectile to sonic and subsonic velocities after said projectile has passed through said low pressure shock decelerator tube, and adDitional decelerator tubes axially aligned with said low and high pressure shock decelerator tubes having diaphragms over the ends thereof for building up pressure therein for slowing said projectile from sonic velocities to a standstill after said projectile has passed through said high pressure shock decelerator tube.
Claim 8
Dependent Claim 174 words
In combination with a ballistic range wherein a projectile may be accelerated to high velocities through an environment test chamber, a ballistic compression decelerator including a low pressure shock decelerator tube through which a supersonic shock wave proceeds the advancing projectile, said tube having a diaphragm over the end thereof to cause air in front of said advancing projectile to compress, said ballistic compression decelerator including a high pressure shock decelerator tube axially aligned with said low pressure shock decelerator tube having a diaphragm over the end thereof and precharged to a higher pressure than in said low pressure shock decelerator tube to reduce the velocity of said projectile to sonic and subsonic velocities after said projectile has passed through said low pressure shock decelerator tube, and adDitional decelerator tubes axially aligned with said low and high pressure shock decelerator tubes having diaphragms over the ends thereof for building up pressure therein for slowing said projectile from sonic velocities to a standstill after said projectile has passed through said high pressure shock decelerator tube.
Claim 9
Dependent Claim 154 words
In combination with a ballistic range wherein a projectile may be accelerated to high velocities through an environment test chamber, a ballistic compression decelerator for stopping said projectile without damage thereto comprising a low pressure shock decelerator tube through which a supersonic shock wave proceeds the advancing projectile, said tube having a diaphragm over the end thereof to cause air in front of said advancing projectile to compress, a high pressure shock decelerator tube extending from said low pressure shock decelerator tube and having a diaphragm over the end thereof and precharged to a higher pressure than in said low pressure shock decelerator tube to reduce the velocity of said projectile to sonic and subsonic velocities, and an adiabatic decelerator tube extending from said high pressure shock decelerator tube and having a diaphragm over the end thereof for building up pressure therein for slowing said projectile from sonic and subsonic velocities to a standstill.
Claim 10
Dependent Claim 154 words
In combination with a ballistic range wherein a projectile may be accelerated to high velocities through an environment test chamber, a ballistic compression decelerator for stopping said projectile without damage thereto comprising a low pressure shock decelerator tube through which a supersonic shock wave proceeds the advancing projectile, said tube having a diaphragm over the end thereof to cause air in front of said advancing projectile to compress, a high pressure shock decelerator tube extending from said low pressure shock decelerator tube and having a diaphragm over the end thereof and precharged to a higher pressure than in said low pressure shock decelerator tube to reduce the velocity of said projectile to sonic and subsonic velocities, and an adiabatic decelerator tube extending from said high pressure shock decelerator tube and having a diaphragm over the end thereof for building up pressure therein for slowing said projectile from sonic and subsonic velocities to a standstill.

References Cited (Backward Citations)

US2498045A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-07-25 1976-01-24 1976-07-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-07-25 1980-01-24 1980-07-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-07-25 1984-01-24 1984-07-25 $7700.00 Window Closed / Lapsed

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