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Publication numberUS3861314 A
Publication typeGrant
Publication dateJan 21, 1975
Filing dateDec 30, 1966
Priority dateDec 30, 1966
Publication numberUS 3861314 A, US 3861314A, US-A-3861314, US3861314 A, US3861314A
InventorsIrwin R Barr
Original AssigneeAai Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Concave-compound pointed finned projectile
US 3861314 A
Abstract
A projectile adapted to curl and tumble on impact with a target, and having a long cylindrical shank section with a concave tapered blunt nose and rear stabilizing fins.
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Description  (OCR text may contain errors)

ite States Barr atent 1 CONCAVE-COMPOUND POINTED FINNED PROJECTILE [75] Inventor: Irwin R. Barr, Lutherville, Md. [73] Assignee: AAI Corporation, Cockeysville, Md.

[22] Filed: Dec. 30, 1966 [21] AppI. No.1 606,453

[52] U.S. Cl l02/92.l, 102/D1G. 7 [51] Int. Cl. F4lb 13/00 [58] Field of Search 102/38, 42, 91, 52, 53,

[56] References Cited UNITED STATES PATENTS 213,083 3/1879 Wright et a1 273/1065 5] .Ian. 21, 1975 2,288,562 6/1942 Birkhofcr et a1 273/1065 FOREIGN PATENTS OR APPLICATIONS 619,192 3/1949 Great Britain 1. 273/1065 Primary ExaminerVerlin R. Pendegrass Attorney, Agent, or FirmRegina1ld F. Pippin, Jr.

[57] ABSTRACT A projectile adapted to curl and tumble on impact with a target, and having a long cylindrical shank section with a concave tapered blunt nose and rear stabilizing fins.

4 Claims, 6 Drawing Figures IPATENTEDJANZI m5 3861.314

Fig. 5

I RW l N R. BARR INVENTOR ATTORNEY CONCAVE-COMPOUND POINTED FINNED PROJECTILE This invention relates to fin-stabilized projectiles and is particularly applicable to small needle-like finned projectiles commonly referred to as flechettes or flechette projectiles.

Flechette projectiles such as shown in U.S. Pat. No. 2,939,395 are highly advantageous in their ability to travel long distances at high velocities, with good accuracy. For maximum effectiveness after impact as an antipersonnel weapon it is desirable that these flechettes be stable along their air flight path and curl and tumble upon impact with a soft, dense target. This tumbling action occurs at a certain minimum velocity. While projectiles will tumble to some degree if the velocity is sufficiently great at impact, it is desirable that the required or critical impact tumbling velocity be as low as possible. This invention aids in decreasing the required target impact velocity for a finned projectile to tumble within an effective travel of one or two projectile lengths after impact.

Tumbling action may be caused by a pitching moment applied at the nose of the projectile, which is of sufficient magnitude that it cannot be balanced by the fins, or which causes the projectile to bend or curl so that the fins are no longer operative in the new medium. Although a tin-stabilized projectile is stable during air flight, by weakening the nose section through formation in a desired concave shape according to the invention, the projectile is given an increased capability of bending and producing an unbalancing pitching moment after impact on striking a denser medium such as an animal. The concave shape of the nose section reduces the strength at the point where the highest loads are applied and deforms the point causing a high pitching moment and resulting in tumbling of the entire projectile at a lower velocity than with a conventionalnosed fin-stabilized projectile.

It is accordingly a major feature of the present invention to provide an improved projectile in the form of a flechette which is capable of a reasonable accuracy in flight but which will tumble in a desired manner on impact at a relatively lower velocity with a higher density target and is capable of reasonable handling in assembly without point deformation.

It is also a feature of this invention to provide a finstabilized projectile with a small blunt end having a lowered impact tumbling velocity. While flechettes having a needle sharp pointed configuration can produce low velocity impact tumbling action, such configurations are difficult to handle in assembly, etc., without damage and consequent deterioration of air flight performance characteristics. The long concave point can accomplish the same action although the very tip has a small blunt face rather than a perfect point. With the present invention the projectile may have a blunt nose end diameter of as much as .1 caliber (the body diameter of the flechette being defined as one caliber).

Still other objects, features and attendant advantages will become apparent to those skilled in the art from a reading of the following detailed description of a single embodiment constructed in accordance with the invention, taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a flechette according to the invention,

13 with a tail section 15 having stabilizing fins 15a formed thereon as by swaging of the metal from the cylindrical body section into the configuration as indicated in FIG. 1. The forward end of the projectile has a concave compound angle point 117, formed by two adjoining frusto-conical surfaces 17a: and 17b. The frustoconical section 17a is formed with a greater included angle A than the included angle B formed by the surface of frusto-conical section 171). It has been found that a very advantageous construction of the invention, which provides good flight accuracy, with good handling characteristics and desired tumbling action, is attained with a projectile as illustrated in FIGS. l-3 in which the dimensions, material and treatment are as follows:

Total length of flechette 1.6 1.7 inches Included angle A 10 12 Included angle B S 7 Tip diameter C Cylindrical body diameter D X ll 11 11 ll 11 11 Best results have been obtained with an included angle A of 10 and included angle B of 6, the preferred tip diameter C being 0.004 0.005 inches, cylindrical body diameter D 0.070 inches, total length of flechette 1.67 inches, and X being 0.1 1 inches, this being particularly most advantageous for employment in cartridge casings of .22 caliber ammunition employing the flechette and sabot arrangement of U.S. Pat. No. 2,939,395.

In operation, the projectile is propelled by a suitable means, such as through initial gas pressure propulsion while carried in a barrel by a sabot as in U.S. Pat. No. 2,939,395, which sabot may be stripped from the projectile as by a stripper as shown in U.S. Pat. No. 2,811,901. Upon impact with a target, the concave nose section 17 will bend, first along the weakest tapered section 17b, causing a high pitching moment to. be applied to the nose of the projectile. This introduces a tumbling action and causes additional bending of the projectile to a generally curled configuration such as the configurations indicated schematically in FIGS. 4-6. The finned section may in some instances break loose from the remaining body portion, as generally illustrated in FIG. 6. The tumbling action transmits much more of the energy of the projectile to the target. Without tumbling, the projected area of the crosssectional envelopes of the projectile transmits the energy to the target. With tumbling, the side projected area with flechettes of for instance a 10:1 length/crosssectional envelope transmits over ten times the energy over the same distance. The tumbling projectile will thereby effect considerably more damage to a relatively soft and thick target, such as an animal, than would otherwise be effected by passage of the projectile thereinto or therethrough in the straight elongated form.

While the invention has been described with respect to a preferred physical embodiment, it will be readily apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope or spirit of the invention. Accordingly, the invention is not to be limited by the specific illustrative embodiment, but only by the scope of the appended claims.

That which is claimed is:

1. A one piece projectile adapted to curl and tumble on impact with a target, comprising: a long cylindrical shank section, a blunt nosed concave tapered forward end section integral with and materially shorter than said shank section, and a rear section integral with said shank section and having integral stabilizing fins formed thereon.

2. A projectile according to claim 1, said concave tapered forward end section having a substantially flat tip end and being formed with two distinct adjoining tapered frusto-conical surfaces having an annular junction line between said cylindrical shank section and said flat tip end, the forwardmost of said frusto-conical surfaces forming a smaller longitudinally extending included angle between its diametral surfaces than the other said frusto-conical surface and being substantially shorter than the other frusto-conical surface.

3. A projectile according to claim 2, said smaller longitudinally included angle formed by said forwardmost frusto-conical surface being in the range of approximately 5-7, said other adjoining rearward frustoconical surface longitudinally included angle being in the range of approximately 10-12 the ratio of said forwardmost frusto-conical surface length to the other adjoining frusto-conical surface length being about 13, and the ratio of the length of said shank and tail sections to the length of said forward end concave section being at least 3-1, with a total length to shank diameter ratio of at least 15-1.

4. A flechette projectile according to claim 3,

said projectile length being approximately 1.65

inches,

said forwardmost included angle of taper being approximately 10,

the included angle of the other said tapered surface being approximately 6,

the tip end being flat and of a diameter of approximately 0.005 inches,

the cylindrical shank diameter being approximately 0.070 inches, the axial length of the forwardmost frusto-conical surface section being approximately 0.1 1 inches, and the projectile hardness being between R 40 and

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US213083 *Nov 7, 1878Mar 11, 1879 Improvement in bows and arrows
US2288562 *May 17, 1941Jun 30, 1942Kroydon CompanyArrow shaft construction
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US4637313 *Dec 31, 1984Jan 20, 1987Avco CorporationEarth penetrator
US4759293 *Jun 17, 1987Jul 26, 1988Davis Jr Thomas OArticle using shape-memory alloy to improve and/or control the speed of recovery
US4839479 *Jul 18, 1988Jun 13, 1989Davis Jr Thomas OArticle using shape-memory alloy to improve and/or control the speed of recovery
US6920827Oct 31, 2003Jul 26, 2005Raytheon CompanyVehicle-borne system and method for countering an incoming threat
US6931994Nov 21, 2002Aug 23, 2005Raytheon CompanyTandem warhead
US6973878Jun 5, 2003Dec 13, 2005Raytheon CompanyWarhead with aligned projectiles
US7017496Mar 10, 2003Mar 28, 2006Raytheon CompanyKinetic energy rod warhead with imploding charge for isotropic firing of the penetrators
US7143698May 13, 2005Dec 5, 2006Raytheon CompanyTandem warhead
US7412916Jan 18, 2006Aug 19, 2008Raytheon CompanyFixed deployed net for hit-to-kill vehicle
US7415917Mar 10, 2003Aug 26, 2008Raytheon CompanyFixed deployed net for hit-to-kill vehicle
US7621222Feb 17, 2005Nov 24, 2009Raytheon CompanyKinetic energy rod warhead with lower deployment angles
US7624682Feb 17, 2005Dec 1, 2009Raytheon CompanyKinetic energy rod warhead with lower deployment angles
US7624683Jul 20, 2005Dec 1, 2009Raytheon CompanyKinetic energy rod warhead with projectile spacing
US7717042Jan 6, 2005May 18, 2010Raytheon CompanyWide area dispersal warhead
US7726244Jul 20, 2007Jun 1, 2010Raytheon CompanyMine counter measure system
US8127686Jul 20, 2005Mar 6, 2012Raytheon CompanyKinetic energy rod warhead with aiming mechanism
US8418623Apr 2, 2010Apr 16, 2013Raytheon CompanyMulti-point time spacing kinetic energy rod warhead and system
US20040055498 *Feb 20, 2003Mar 25, 2004Lloyd Richard M.Kinetic energy rod warhead deployment system
US20040055500 *Jun 5, 2003Mar 25, 2004Lloyd Richard M.Warhead with aligned projectiles
US20040129162 *Mar 10, 2003Jul 8, 2004Lloyd Richard M.Kinetic energy rod warhead with imploding charge for isotropic firing of the penetrators
US20040200380 *Jun 6, 2003Oct 14, 2004Lloyd Richard M.Kinetic energy rod warhead with lower deployment angles
US20050109234 *Sep 10, 2004May 26, 2005Lloyd Richard M.Kinetic energy rod warhead with lower deployment angles
US20050115450 *Oct 31, 2003Jun 2, 2005Lloyd Richard M.Vehicle-borne system and method for countering an incoming threat
US20050126421 *Nov 21, 2002Jun 16, 2005Lloyd Richard M.Tandem warhead
US20050132923 *Mar 10, 2003Jun 23, 2005Lloyd Richard M.Fixed deployed net for hit-to-kill vehicle
US20060021538 *Oct 7, 2004Feb 2, 2006Lloyd Richard MKinetic energy rod warhead deployment system
US20060086279 *Feb 17, 2005Apr 27, 2006Lloyd Richard MKinetic energy rod warhead with lower deployment angles
US20060112817 *Jan 18, 2006Jun 1, 2006Lloyd Richard MFixed deployed net for hit-to-kill vehicle
US20060112847 *Jan 6, 2005Jun 1, 2006Lloyd Richard MWide area dispersal warhead
US20060162604 *May 13, 2005Jul 27, 2006Lloyd Richard MTandem warhead
US20060283348 *Jul 20, 2005Dec 21, 2006Lloyd Richard MKinetic energy rod warhead with self-aligning penetrators
US20070084376 *Jul 20, 2005Apr 19, 2007Lloyd Richard MKinetic energy rod warhead with aiming mechanism
US20090205529 *Feb 17, 2005Aug 20, 2009Lloyd Richard MKinetic energy rod warhead with lower deployment angles
US20090223404 *Jun 30, 2008Sep 10, 2009Lloyd Richard MFixed deployed net for hit-to-kill vehicle
WO1988000325A1 *Jun 30, 1987Jan 14, 1988Thomas O Davis JrArticle using shape-memory alloy to improve and/or control the speed of recovery
WO2005099362A2 *Oct 13, 2004Oct 27, 2005Richard M LloydMine counter measure system
Classifications
U.S. Classification102/501, 102/703
International ClassificationF42B6/04
Cooperative ClassificationF42B6/04, Y10S102/703
European ClassificationF42B6/04