U.S. patent number 3,890,902 [Application Number 05/421,570] was granted by the patent office on 1975-06-24 for projectile.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Army. Invention is credited to Samuel L. Brown, Bruce W. Travor.
United States Patent |
3,890,902 |
Travor , et al. |
June 24, 1975 |
Projectile
Abstract
A projectile having a pair of longitudinally spaced rotating
bands, one of hich is forwardly adjacent the projectile center of
gravity to provide a projectile bearing surface that minimizes
projectile yaw within and at the exit of the gun barrel. An
improved aerodynamic stability of the projectile at the gun muzzle
exit is obtained, as well as increased projectile accuracy at the
target.
Inventors: |
Travor; Bruce W. (Holland,
PA), Brown; Samuel L. (Willingboro, NJ) |
Assignee: |
The United States of America as
represented by the Secretary of the Army (Washington,
DC)
|
Family
ID: |
23671105 |
Appl.
No.: |
05/421,570 |
Filed: |
December 4, 1973 |
Current U.S.
Class: |
102/526;
102/518 |
Current CPC
Class: |
F42B
12/06 (20130101); F42B 14/064 (20130101) |
Current International
Class: |
F42B
14/06 (20060101); F42B 14/00 (20060101); F42B
12/06 (20060101); F42B 12/02 (20060101); F42B
013/16 (); F42B 013/06 () |
Field of
Search: |
;102/93,92.1,92.2,92.4,92.6,52 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Stahl; Robert F.
Attorney, Agent or Firm: Gibson; Robert P. Edelberg; Nathan
Sommer; William
Government Interests
The invention described herein may be manufactured, used, and
licensed by or for the Government for governmental purposes without
the payment to us of any royalty thereon.
Claims
We claim:
1. In an aerodynamically stable projectile having a heavy
penetrator positioned within a non-discarding sabot,
said non-discarding sabot including a sabot body portion and an
aerodynamic windshield nose member threadedly secured thereto,
said heavy penetrator secured within said sabot body portion and
said nose member,
said nose member having a forward tapered external surface, said
nose tapered surface terminating in a closed forward end,
said sabot body portion having a forward exterior surface
containing a cylindrical portion and a tapered portion forwardly
thereof defining an origin of ogive therebetween, said tapered
sabot portion being a mating continuation of said nose tapered
surface,
said sabot body portion carrying a first rotating band rearward of
the center of gravity of said projectile, and
a second rotating band having a mid-point located on said sabot
body portion forward of said projectile center of gravity.
2. The structure in accordance with claim 1 wherein the ratio of
maximum surface diameters of said second and first rotating bands
is in the range of 0.965 to 0.985.
3. The structure of claim 2 wherein said ratio is 0.975.
Description
This invention relates to projectiles, and more particularly to an
ammunition projectile having a non-discarding sabot body and an
aerodynamic windshield or nose.
Prior ammunition projectiles normally have barrel contacting
surfaces at their rearwardly located rotating band and the
forwardly located origin of ogive for the windshield or nose
portion. This type of arrangement enables the projectile to travel
through the rifled gun barrel at a cocked position, thereby
inducing a certain amount of projectile at muzzle exit yaw that
adversely affects the aerodynamic stability of the projectile as
well as its firing accuracy.
One of the objects of the invention is to provide an ammunition
projectile in which the yaw at muzzle exit is minimized.
Another object of the invention is to provide such a projectile
having an improved aerodynamic stability.
A further object of the invention is to provide such a projectile
having increased firing accuracy.
These and other objects, features and advantages will become more
apparent from the following description and accompanying drawing
which is an elevational view, partially broken away in section, of
a preferred ammunition projectile embodying the principles of the
invention.
The ammunition projectile, shown generally at 10, has a sabot body
portion 11 having a forwardly opening cavity 12 that terminates in
an enlarged internally threaded forward end 13 by which an
appropriately threaded rearward portion 14 of a windshield or nose
member 15 is secured with a heavy penetrator 16 of suitably
contoured metallic material seated or positioned in the cavity 12.
The rearward end of the sabot body has a crimping groove 17 for
attachment of a cartridge case, and slightly forward thereof, a
first rotating band 18 of a copper base material for conventional
engraving by and sealing of the rifling grooves of an associated
gun barrel (not shown).
Spaced longitudinally from and forward of the rotating band 18 is a
second or mid rotating band 19 of similar material but of a
slightly reduced diameter. Preferably, the ratio of the external or
maximum surface diameters of the second and first rotating bands is
0.975, although a satisfactory ratio range of 0.965 to 0.985 will
preclude excessive operational chamber pressures. Preferably, the
projectile center of gravity is located rearwardly adjacent the
mid-point of the second or forward rotating band to attain minimum
projectile eccentricity in the gun barrel and maximum aerodynamic
stability.
The second or mid rotating band assists in imparting projectile
spin and also functions as a forward alignment guide for the
projectile as it travels through and exits from the gun barrel. It
has been found that by positioning the second rotating band only a
proportional distance from the forwardmost peripheral edge of the
first rotating band as compared to the distance between the latter
and the origin of ogive (located at 20 and no longer functioning as
the forward guide), a substantial reduction of the yaw muzzle exit
angle is obtained for the launched projectile. For example, the
proportional distance of 42.6% for the preferred projectile will
reduce the yaw muzzle exit angle by in excess of 50%.
Various modifications, alterations or changes may be resorted to
without departing from the scope of the invention as defined in the
appended claims.
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