Ammunition and explosives – Projectiles – Composite
Reexamination Certificate
2003-09-11
2004-08-31
Carone, Michael J. (Department: 3641)
Ammunition and explosives
Projectiles
Composite
C102S527000, C102S439000, C102S521000
Reexamination Certificate
active
06782830
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to obturators for use on ammunition, and, more particularly, for obturators for use on 45 mm or higher caliber ammunition for smooth bore guns.
BACKGROUND OF THE INVENTION
Obturators are used on projectiles for sealing combustion gases and guiding the projectile through a gun tube. In operation, an obturator seals gases between both the tube/obturator and obturator/projectile interfaces. It will be appreciated that obturator design is very critical in making a good seal in the gun tube in order to attain required muzzle velocity during firing. At the same time, the obturator should promote manual round chambering and extraction without the use of significant force. Obturators are usually discarded at muzzle exit and, since the weight of obturator is considered parasitic, it should be as light as possible without sacrificing functionality.
Traditional obturators are located in the forcing cone region of a gun tube and are usually slightly super-caliber. Initial pressurization moves the obturator forward so that it is compressed between the projectile and tube to create an initial seal. As generated pressure increases, the projectile moves with the obturator forward into the straight part of a tube. As the obturator contacts the gun tube bore surface, the obturator is subsequently pushed back due to its super-caliber size. As pressure continues to increase in the gun tube, the obturator again moves forward with the projectile. Before the present invention, the aforesaid complex movement of an obturator with the projectile required an additional sealing agent between the obturator and projectile. Typically the sealing agent used is a well-known room temperature vulcanizing sealant, called JRTV.
U.S. Pat. No. 6,453,821 to Fowler, et al. issued Sep. 24, 2002, entitled “High-Temperature Obturator for a Gun-Launched Projectile,” discloses an obturator for a projectile launched from a gun barrel. The obturator includes an annular ring that is fabricated from a high-temperature resistant composite material. The annular ring has an inner surface that is in contact with the projectile.
U.S. Pat. No. 6,419,235 to Han, issued Jul. 16, 2002, entitled “Segmented Obturator Ring,” discloses an obturator ring comprising two or more pieces each being a little larger than semicircle of the projectile obturator ring groove circumference. Each piece at natural position has equal or smaller radius than the radius of the obturator ring groove of a projectile; therefore, each piece expands to be in the projectile groove.
U.S. Pat. No. 6,295,934 to Tepera, et al. issued Oct. 2, 2001, entitled “Mid-body Obturator for a Gun-launched Projectile,” discloses an obturator for a projectile having a mid-body annular groove that includes a shaped surface. The obturator includes an annular ring having an inner surface in contact with the shaped surface of the annular groove of the projectile. The annular ring further includes an outer surface. When the projectile is in the gun barrel, the outer surface of the annular ring contacts an inner surface of a bore of the gun barrel.
U.S. Pat. No. 6,223,643 to Muller issued May 1, 2001, entitled “Obturator for a Gun,” discloses an obturation assembly for a gun of the type comprising a barrel of which a rear end defines a firing chamber having an obturation seat and the gun further having a breechblock, the obturation assembly comprising: an obturation set including an annular obturator pad for sealing against the obturation seat; an obturation spindle having a shaft and a head, the shaft extending coaxially through the obturator pad; a first shim for location between the obturation set and the breechblock, and a second shim for location between the obturation set and the head of the obturation spindle.
U.S. Pat. No. 6,085,660 to Campoli issued Jul. 11, 2000, entitled “Low Spin Sabot,” is directed to a discardable sabot including a first support and a second support, aft of the first support. At least one of the supports is a sealing support, configured to provide a substantially gas-tight seal with the barrel and effective to allow the sabot and the projectile to be propelled forward through the barrel by expansion of propellant gas behind the sealing support
U.S. Pat. No. 5,929,364 to Tortorici, et al. issued Jul. 27, 1999, entitled “Obturator Sealing Means for a Split Wedge/Breechblock Gun,” is directed to an obturator for guarding the primary sealing surfaces of a step wedge breechblock gun from post-firing residue buildup. Their device includes an active tube insert for facilitating face seal force multiplication, out of bore lip and face seals, an in bore piston polymer with expanding residue guard, and an out of bore face seal with a residue-tolerant polymer.
U.S. Pat. No. 5,750,919 to Jehle issued May 12, 1998, entitled “Self-Adjusting Obturator for Projectile Launching,” discloses an obturator wherein propellant pressure forces generated within the bore of a gun barrel are applied to a projectile through a self-adjusting obturator to prevent projectile blow by of propellant explosion products. The propellant forces are transmitted through a body of shock-absorbing fluid in the obturator.
U.S. Pat. No. 5,012,991 to Pinson issued May 7, 1991, entitled “Projectile with an Obturator Incorporating a Motor,” discloses a tube-launched projectile including an airframe with an open aft end, an optical fiber dispensing bobbin, and an obturator having a rocket motor attached to a hard point in the aft end of the airframe. The obturator forms a pressure vessel with insulated inner walls that contain rocket propellant and an igniter. An ejectable plug located in the rocket nozzle is expelled upon motor ignition.
U.S. Pat. No. 4,907,513 to Manion, et al. issued Mar. 13, 1990, entitled “High Volume Obturator Assembly Method,” discloses an obturating band of the despun variety manufactured within the channel of a projectile assembly. A split ring polymer pre-band is clamped around the band seat of the projectile assembly and the free ends are welded together to form a continuous ring around the diameter of the projectile assembly within the encircling channel.
United States Patent Office Publication H167 to Forster, et al. published Dec. 2, 1986, entitled “Projectile Obturator,” is directed to a multipurpose projectile obturator of composite, frangible construction where the obturator forms part of a projectile that is launched from an upstanding tube. The obturator is generally made up of an elastomeric band of a suitable grade of rubber.
U.S. Pat. No. 4,552,071 to Horais, et al. issued Nov. 12, 1985, entitled “Two-Piece Despin Obturator,” is directed to a two-piece despin obturator mounted on a forwardly inclined obturator ramp on the projectile sidewall has a ring-shaped body of nylon-6 and a wiper band formed from Plascon nylon. The rotational velocity imparted to the ring is partially coupled as the inner surface of the ring rotates on the obturator mount of the projectile.
U.S. Pat. No. 4,444,113 to Campoli issued Apr. 24, 1984, entitled “High-Pressure Self-Sealing Obturator in Sabot Discard Projectile,” is directed to a high-pressure self-sealing obturator positioned to fit on the rear of a sabot assembly in a discarding projectile assembly to prevent the obturator from backing off during initial impact of bore walls by the projectile assembly. The obturator includes an extension and a groove for snapping a case mouth into the extension. The outer surface of the obturator conforms to the bore of the gun.
U.S. Pat. No. 4,242,961 to Moredock, et al. issued Jan. 6, 1981, entitled “Chevron Grooved Decoupling Obturator,” is directed to an obturator for a projectile to be fired from a rifled barrel, with the obturator being mounted on the projectile in such a way as to permit rotational slippage. An external portion of the obturator ring has a plurality of encircling slots, essentially parallel to each other, which slots are rearwardly inclined so as to define a plurality of chevron-like members designed to forcibly engage
Candland Calvin T.
Dohrn Rollie H.
Kamdar Dipak S.
Alliant Techsystems Inc.
Carone Michael J.
Levine George A.
Semunegus L.
LandOfFree
Obturator for large caliber smooth bore ammunition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Obturator for large caliber smooth bore ammunition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Obturator for large caliber smooth bore ammunition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3315445