Patent Application
20100212531
The present invention provides a flechette cartridge having flechettes contained therein which, when fired, are accelerated without spin being imparted thereto. In particular, a flechette cartridge is provided containing flechettes which are accelerated within the cartridge case without spin imparted thereto, and which do not engage the barrel rifling, thus allowing flechettes to stabilize quickly and avoiding an excessive spread pattern during a firing event.
Conventional flechette rounds, such as the M1001, contain approximately 113 flechettes, each flechette weighing 18 grains. The flechettes contained within such conventional rounds reach average velocities of approximately 790 ft/sec. Such velocities are satisfactory. The M1001 uses a heavy projectile body to carry the flechette payload down the barrel. The projectile body uses a slip band obturator to minimize spinning the projectile body and flechette payload in the barrel rifling.
Conventional payload carriers are stripped from the flechette payload by propellant gases and a spring, which are deficient in stripping the payload carriers from the flechette payloads. Further, the payload carrier is formed of a heavy metal body, which undesirably functions as a parasitic mass. This means of stripping the flechette payload carriers results in undesired dispersion characteristics. The relatively heavy metal body results in reduced muzzle velocities and reduced kinetic energy, reducing the effectiveness of the flechettes.
It is an object of the present invention to provide a flechette cartridge which maximizes the muzzle velocity of the flechettes by minimizing the parasitic mass associated with the flechette carrier. It is a further object of the present invention to provide a robust means for reliably stripping the flechette carrier.
In order to achieve the object of the present invention as described above, the present inventor earnestly endeavored to develop a flechette cartridge capable of launching flechettes in a concentrated, predictable spread pattern at a relatively high muzzle velocity. Accordingly, in a first embodiment of the present invention, a flechette cartridge is provided comprising:
(a) a cartridge case having:
(b) a primer disposed within the primer cavity;
(c) a propellant charge disposed within the high pressure chamber;
(d) a sub caliber payload cup slidably disposed within the smooth-bored cartridge barrel, adjacent the low pressure chamber, the sub caliber payload cup having:
In a second embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, wherein the payload cup body further comprises a metal disk disposed therein, within the inner circumference of the payload cup body, adjacent the inner base. This metal disk prevents the flechettes from digging into the payload cup body upon firing.
In a third embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, wherein the payload cup further comprises a payload cup stripping means in communication with the cartridge case at a first end, and with the payload cup at an end opposite the first end,
wherein, when the flechette cartridge is fired, the payload cup is propelled from the smooth bored cartridge barrel and, at a predetermined distance from the smooth bored cartridge barrel, the payload cup stripping means acts upon the payload cup to strip the payload cup from the flechettes. The flechette retaining means generally disintegrates upon being exposed to the high velocity airstream, allowing the flechettes to fly unimpeded to the target.
In a fourth embodiment of the present invention, the flechette cartridge of the third embodiment is provided, wherein the payload cup stripping means is comprised of a line or string.
In a fifth embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, wherein a barrel ridge is formed on the smooth-bored cartridge barrel, and a payload cup ridge is formed on the payload cup, adjacent the outer base thereof. Upon firing, the payload cup ridge and barrel ridge are caused to impact one another, thereby decelerating the payload cup.
In a sixth embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, comprising a plurality of sub caliber payload cups disposed within the smooth-bored barrel, with separator disks disposed therebetween.
In a seventh embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, further comprising an ogive cap removably disposed on the cartridge case adjacent the open mouth of the smooth bored barrel.
In an eighth embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, further comprising a metal disk disposed within the cartridge barrel between the low pressure chamber and the payload.
In a ninth embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, wherein an empty volume is present within the cartridge barrel between the payload cup and the open mouth of the smooth-bored barrel. Longer cartridge barrel lengths allow for gentler payload accelerations, with lower required peak propellant pressures.
In a tenth embodiment of the present invention, the flechette cartridge of the first embodiment above is provided, further comprising a closure disk disposed within the cartridge barrel, adjacent the flechettes and flechette retaining means of the sub caliber payload cup.
In an eleventh embodiment of the present invention, the flechette cartridge of the first embodiment is provided, comprising a plurality of sub caliber payload cups.
In a twelfth embodiment of the present invention, a flechette cartridge is provided comprising:
(a) a cartridge case having:
(b) a primer disposed within the primer cavity;
(c) a propellant charge disposed within the cartridge case body;
(d) a sub caliber payload cup slidably disposed within the smooth-bored cartridge barrel, the sub caliber payload cup having:
As illustrated in
A primer 19 is disposed with the primer cavity 9, and high pressure chamber 21 is disposed adjacent the primer cavity 9. A low pressure chamber 23 is disposed adjacent the high pressure chamber 21. A propellant charge 25 is disposed within the high pressure chamber 21. When fired, the weapon firing pin strikes the primer 19, and the primer 19 ignites, subsequently igniting the propellant charge 25.
A sub caliber payload cup 27 is disposed within the smooth-bored cartridge barrel 15, adjacent the low pressure chamber 23. Alternatively, a single propellant chamber can be used, wherein the propellant is ignited and propels the payload cup down the barrel, venting at the muzzle. The sub caliber payload cup 27 is comprised of a flechette retaining means 29 for retaining flechettes, and for sealing propellant case within the cartridge barrel, and a plurality of flechettes 31 retained therein. The flechette retaining means 29 is, generally, formed of a plastic or composite material, but may be formed of a metallic material, and has a structure containing numerous protrusions therein for frictionally retaining the flechettes 31.
As called for in the eighth embodiment of the present invention herein, and as illustrated in
Preferably, the sub caliber payload cup 21 further comprises a payload cup stripping means 33, as illustrated in
The line or string is preferably designed to break near the attachment point inside the cartridge case 3 (i.e., at or adjacent to the first end 35), to eliminate having the string remaining in the barrel after firing. This is accomplished by creating a weak point, such as a knot, near attachment point of the line or string to the cartridge case 3. The process of breaking the string or line extracts sufficient kinetic energy from the flechette payload cup 33 to reliably strip the payload cup 33 from the flechettes 31.
As called for in the fourth embodiment of the present invention, the flechette cartridge 1, as illustrated in
As illustrated in
As illustrated in
As illustrated in
In a preferred embodiment, as illustrated in
Although specific embodiments of the present invention have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments. Furthermore, it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the present invention.
