CARTRIDGE FOR SMALL ARMS

CARTOUCHES POUR PETITES ARMES

English Abstract

ABSTRACT OF THE DISCLOSURE
A cartridge for use with a revolver, automatic or submachine
gun has a brass casing. The interior of the casing has a
substantially planar bottom wall extending radially from its
flash hole. A primer pocket in the base communicates through the
flash hole with the casing interior within which the powder is
ignited. A parabolic curved section extends from the planar
bottom wall to a sloped wall section. The slope is in the range
from substantially 5 to 15 degrees. The casing wall thus narrows
forwardly and terminates in an area of substantially uniform or
constant thickness within which the bullet is frictionally
retained. With the parabolic curved section, the relocation of
forces due to the discharging gases is substantially in a line
which is parallel with the longitudinal axis of the cartridge.
The projectile velocity is thus substantially increased without
subjecting the cartridge to undesired expansion, cracking or
distortion. This increases the firepower while eliminating the
jamming problems occasionally incurred during the firing of
automatic weapons.

Claims

What Is Claimed Is:
1. In a cartridge for use with a revolver, automatic,
submachine gun or the like, wherein the cartridge includes a
casing having a substantially linear outer wall and further
having a base at one end thereof, and wherein the base has a
primer pocket communicating with the interior of the casing
through a flash hole: the improvement which comprises the casing
interior including a powder charge area having a planar bottom
wall extending radially outwardly from the flash hole, a
substantially parabolic curved section extending forwardingly of
the planar bottom wall, whereby the discharge forces are
substantially parallel to the longitudinal centerline of the
cartridge; the casing further including an interior wall having a
substantially-linear sloped wall section extending forwardly of
the parabolic curved section, wherein the thickness between the
sloped wall section and the outer wall of the casing narrows
forwardly of the parabolic curved section; the sloped wall
section terminating at a transition area which defines a
substantially lowermost nesting portion for a bullet disposed
within the casing; the casing further having a linear wall
forwardly of the transition area; wherein the thickness between
the linear wall and the outer wall is substantially constant;
wherein the sloped wall section defines a zone of increasing
thickness from the transition area rearwardly to the parabolic
curved section; and wherein the parabolic curved section defines
a zone of still greater thickness rearwardly of the sloped wall
section.
- 6 -

2. The cartridge of claim 1, wherein the casing is made of
brass.
3. The cartridge of claim 1, wherein the base has an
annular rim, and wherein a transition area between the annular rim
and the outer wall includes an extractor groove and a bevel.
4. The cartridge of claim 1, wherein the sloped wall
section has a slope of substantially within the range of 5 to 15
degrees.
5. In a cartridge for use with a revolver, automatic,
submachine gun or the like, wherein the cartridge includes a
casing made of brass and having a substantially linear outer wall
and further having a base at one end thereof, wherein the base
has an annular rim, wherein a transition area between the rim of
the base and the outer wall includes an extractor groove and a
bevel, and wherein the base has a primer pocket communicating
with the casing interior through a flash hole: the improvement
which comprises the casing interior including a powder charge
area having a planar bottom wall extending radially outwardly
from the flash hole, a substantially parabolic curved section,
extending forwardly of the planar bottom wall, whereby the
discharge forces are substantially parallel to the longitudinal
centerline of the cartridge; the casing further including an
interior wall having a substantially-linear sloped wall section
extending forwardly of the parabolic curved section, wherein the
thickness between the sloped wall section and the outer wall of
the casing narrows forwardly of the parabolic curved section; the
sloped wall section terminating at a transition area which
- 7 -

defines a substantially lowermost nesting portion for a bullet
disposed within the casing; the casing further having a linear
wall area forwardly of the transition area; wherein the thickness
between the linear wall and the outer wall is substantially
constant; wherein the sloped wall section defines a zone of
increasing thickness from the transition area rearwardly to the
parabolic curved section; and wherein the parabolic curved
section defines a zone of still greater thickness rearwardly of
the sloped wall section.
- 8 -

6. A cartridge for use with a revolver, automatic or
submachine gun comprising in combination:
a single piece casing made of brass and having a
substantially linear outer wall;
a transition bevel at one outer wall end of said casing
terminating in an extractor groove area, said extractor groove
area being connected to a base which includes an annular rim,
and a primer pocket extending through said base communicating
with an interior of said casing through a flash hole, said
interior including a powder charge area having a planar bottom
wall extending radially outwardly from said flash hole
terminating thereafter into a substantially parabolic curved
section utilizing parabolic curve axiom that requires discharge
forces to travel parallel to the longitudinal center-line of the
cartridge, and an interior wall extending forward from said
parabolic section, and
wherein said interior wall includes a sloped wall section
extending from said parabolic curved section, said sloped wall
section in combination with said outer wall narrowing in
thickness as it extends away from said parabolic curved section,
wherein said sloped wall section terminates at a transition
area which defines a lowermost nesting portion neck for a bullet
disposed within said cartridge, forward said transition area
thereafter providing a linear inner wall defining a zone of
constant thickness with said outer wall,
wherein said sloped wall section defines a zone of
increasing thickness from said transition area to said parabolic
curved section having a slope of 5-15 degrees,
wherein said parabolic curved section defines a zone of
greatest thickness of said wall, and
wherein said sloped wall section is linear in longitudinal
section.
- 9 -

Description

~ y r ~
A CARTRIDGE FOR SM~LL AR~S
FIELD OF THE INVENTION
The present invention relates to a cartridge for firearms,
and more particularly, to a cartridge for use with a revolver,
automatic, submachine gun or the like.
BACKGROUND OF THE INVENTION
It is well known that there are existing standards for the
external dimensions of cartridges used in firearms. For reliable
service, the outside diameter of a particular cartridge, its
projectile diameter, flash hole dimension, and primer pocket must
all be within prescribed limits to assure proper utilization in a
specific firearm. For example, for .41 caliber cartridges, the
inner diameter of the upper portion of the cartridge should be
0.41 inches, while the overall length of the cartridge
approximates 0.9 inches. Thus, the contour of the cartridge body
is the only area where the performance of the bullet can be
altered, thereby altering projectile velocity, within certain
limits determined by the strength of the shell casing and the
powder charge contained therein.
SUMMARY OF THE INVENTION
As distinguished from the prior art, the present invention
substantially increases the projectile velocity, but does not
expose the cartridge to an increased likelihood of unwanted

~2~ 64
expansion, cracking, or distortion. More specifically, and in
accomplishing this objective, the present invention uses a
parabolic configuration at the head end of the cartridge body.
The axiom of the parabolic curve is used to direct the forces of
the discharged gas generally against the mouth of the cartridge
case and substantially parallel to the centerline of the
cartridge body from the flash hole to the cartridge mouth.
Accordingly, it is an object of the present invention to
provide a new and novel cartridge.
It is another object to provide an improved cartridge,
especially for a .41 caliber firearm.
It~ is another object to provide an improved cartridge having
a very durable construction, one not susceptible to bulging,
expanding, cracking or distorting due to the relatively-high
internal gas pressures during firing.
It is a further object to provide an improved cartridge
which is very safe to use, yet is readily adapted to mass
production.
These and other objects of the present invention will be
apparent from the following detailed specification, taken in
conjunction with the enclosed drawing.
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 is a longitudinal section of the improved cartridge
of the present invention.
Figure 2 corresponds substantially to Figure 1, but shows
the bullet therein in broken lines.
Figure 3 is a top plan view of the cartridge, the bullet
being removed.

5~-~
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, the improved cartridge 10 of the
present invention includes a casing which is preferably made of
brass. The casing is cylindrical and has a substantially linear
outer wall 1. The casing further has a base 4 formed with an
annular rim 3. A transition area between the rim 3 and the outer
wall 1 includes an extractor groove 2 of reduced diameter and a
transition bevel 5.
The base 4 includes a recess 6 defining a primer pocket.
This pocket communicates with the casing interior 19 through a
substantially-cylindrical flash hole 7. The casing interior 19
serves as a powder charge area. In one embodiment, the flash
hole 7 has a reduced diameter (compared to the prior art) so that
the gases in the casing interior release at a slower rate to
provide a greater projectile velocity.
In accordance with the teachings of the present invention,
the internal configuration of the powder charge area has been
maximized. More specifically, a planar bottom wall 11 extends
radially outwardly from the flash hole 7 and terminates at a
parabolic curved section 12. This parabolic curved section 12
extends forwardly of the planar bottom wall 11, and ends at point
9. The substantially parabolic contour of curved section 12
causes the reflection and diffusion of forces from ignition in
the powder charge. More particularly, the parabolic curved
section causes the radiation of forces to be parallel with the
longitudinal axis of the cartridge. By way of example, for .41
caliber ammunition, the inner diameter of curved section 12 is
0.220 inches at the planar bottom wall 11 and 0.370 inches at
point 9.
-- 3 --

1~6~5~
A substantially linear sloped wall section 13 extends
forwardly of the parabolic curved section 12. The sloped wall
section 13 defines an angle C, which is preferably in the range
from substantially 5 to 15 degrees. As a result, the casing wall
tapers in thickness away from the bas~ 4. This provides an area
of greater thickness near to the base, where the load imposed
upon the wall by igniting the powder charge in area 19 is
greatest, and where the external support of the cartridge in the
chamber is the least. The sloped wall section 13 terminates at a
band or transition area 15 which provides a stop or lowermost
nesting portion for the bullet B. Thereafter, a substantially
linear section 14 is provided, running parallel to the outer wall
l. As a result, the casing has a zone of substantially constant
thickness (as shown at 17). As shown in Fig. 2, the bullet B is
frictionally disposed within this zone 17 of substantially
constant thickness.
Rearwardly of the casing, the zone of constant thickness is
followed by a zone 16 of increasing thickness. This zone 16 is
formed by the sloped wall section and extends rearwardly from the
bullet towards the base of the casing. The zone 16 of increasing
thickness is thereafter followed by a zone of still greater
thickness as defined by the parabolic curved section. Upon
ignition, the expanding gases exert a tremendous force within the
powder charge area 19, which causes the bullet to be discharged
at an exceedingly high velocity. However, in accordance with the
present invention, the various thicknesses of the casing wall
will retard any bulging and will minimize any likelihood of
fracture.

5~4
Obviously, many modifications may be made without departing
from the basic spirit of the present invention. Accordingly, it
will be appreciated by those skilled in the art that within the
scope of the appended claims, the invention may be practiced
other than has been specifically described herein.

Representative Drawing