U.S. patent application number 10/597654 was filed with the patent office on 2008-09-11 for lead free monobloc expansion projectile and manufacturing process.
Invention is credited to Laudermiro Martini Filho.
Application Number | 20080216700 10/597654 |
Document ID | / |
Family ID | 34831999 |
Filed Date | 2008-09-11 |
United States Patent
Application |
20080216700 |
Kind Code |
A1 |
Martini Filho; Laudermiro |
September 11, 2008 |
Lead Free Monobloc Expansion Projectile and Manufacturing
Process
Abstract
The present invention relates to a bullet made of a single solid
piece of deformable metal, containing no lead or toxic material,
easily deformable but without fragmentation in a soft environment
with a high rate of energy transfer, and a high level of solidity
in hard targets, retaining most or its total initial weight while
penetrating those targets. Said objects are achieved by
constructing a solid monobloc bullet with a cavity on the
longitudinal axis which is opened towards the fore end of the
bullet. The method of construction encompasses a sequence of simple
operations: cutting of a cylinder blank of soft material, forming a
cavity centered on the longitudinal axis, and forming an ogival or
conical form, with external pre-cuts to foster an homogenous
deformation. The present invention applies to any handgun, rifle or
shotgun ammunition; when used in smoothbores, the essential
stability of the bullet is achieved by positioning the center of
gravity ahead of the aerodynamic cent
Inventors: |
Martini Filho; Laudermiro;
(Ribeirao Pires, BR) |
Correspondence
Address: |
EDWARD YOO C/O BENNETT JONES
1000 ATCO CENTRE, 10035 - 105 STREET
EDMONTON, ALBERTA
AB
T5J3T2
CA
|
Family ID: |
34831999 |
Appl. No.: |
10/597654 |
Filed: |
February 6, 2004 |
PCT Filed: |
February 6, 2004 |
PCT NO: |
PCT/BR04/00006 |
371 Date: |
August 2, 2006 |
Current U.S.
Class: |
102/509 ;
86/54 |
Current CPC
Class: |
F42B 12/34 20130101;
F42B 12/74 20130101 |
Class at
Publication: |
102/509 ;
86/54 |
International
Class: |
F42B 12/34 20060101
F42B012/34; F42B 33/00 20060101 F42B033/00 |
Claims
1. An expansion projectile for firearms, comprising one single
piece of material from the copper class, or copper alloy,
presenting a generally cylindrical shape with a fore portion
generally of conical or ogival shape, and a bottom portion with a
rounded or truncated conical portion; said projectile featuring an
internal cavity opened towards the front end of the projectile,
being said cavity symmetrically centered regarding the longitudinal
axis of the projectile; being the radius (r) descriptive of a
circumference that establishes a circular cross section
perpendicular to the central longitudinal axis of the projectile
and (d) descriptive of the abscises of a generic point which lies
in said longitudinal axis of the projectile, being the shape of the
internal cavity of the projectile described by the values of (r, d)
taking as origin for said coordinates system the point of the
longitudinal axis of the projectile which lies in the same plan
that contains the forward most section of the projectile, with d=0
corresponding to the front end of the projectile and the maximum
value of d corresponding to the bottom of the cavity; characterized
by the fact that the maximum value of r is situated between the
positions where the value of d=0 and d=d.sub.maximum; said radius r
decreases progressively towards the front end where d=0; said
radius r decreases progressively towards the bottom of the cavity
where d=d.sub.maximum; where d=0 (front end of the projectile) said
radius r ranges from 10% to 40% of the caliber of said projectile;
the maximum value of said radius r of said internal cavity ranges
from 10% to 40% of the caliber of the projectile; where
d=d.sub.maximum (bottom of the cavity) said radius r ranges from 0
(flat surface) to 35% of the caliber of said projectile (rounded
bottom); d.sub.maximum ranges from 0.50 to 2.5 times the caliber of
said projectile; the transversal and longitudinal cross-sections of
said cavity present radial symmetry regarding the longitudinal axis
of said projectile, being said cavity cross-section of a circular
or other regular geometrical figure shape.
2. The expansion projectile as defined in claim 1, in which the
external surface features a plurality of lengthwise grooves or
slits parallel to the central longitudinal axis of the projectile
and symmetrically distributed around it, being said grooves or
deformations obtained by pressure forming, when the fore portion is
partially closed in a die to form the generally conical or ogival
shape of the fore portion of projectile; being said grooves or
slits preferably provided in a number of 3 to 9, extending
longitudinally from the front open end to the generatrice where the
case mouth is crimped; being said projectile characterized by the
fact that the total cross sectional area of said grooves or slits
ranges between 0.2 and 5% of the total cross sectional area of the
projectile; said grooves or slits preferably featuring an
essentially triangular cross-sectional shape; and being the length
of the said grooves preferably more than 5% of the length of the
internal cavity of said projectile.
3. The expansion projectile as defined in claims 1 or 2,
characterized by the fact that the internal cavity is obtained by
means of cold forming a raw material cylinder blank obtained by
cutting a wire or rod preferably by shearing of suitable material,
such as copper or copper alloy, applying a single or more strikes
of suitable punches on the cylinder blank creating a deformation
which is axially symmetrical to the longitudinal axis of said
cylinder blank, said obtained final deformation forming a
preliminary internal cavity presenting a larger radius r toward the
front end of the projectile where d=0 is zero, with the radius r of
said preliminary internal cavity varying preferably as: the maximum
value of radius r of said preliminary internal cavity is situated
where d=0, ranging preferably from 95% to 70% of the radius of said
cylinder blank; With a cylindrical portion, situated between the
front end and the bottom of the cavity, the length of said
cylindrical portion ranging from zero to twice the diameter of said
cylinder blank; The radius r of said preliminary internal cavity
decreasing from where d=0 to d=d.sub.maximum where the radius r
ranges from 35% of the diameter of said cylinder blank to r=0; The
maximum value of d ranges from 0.50 to 2.5 times the diameter of
said cylinder blank.
4. Manufacturing process for the expansion projectile as defined in
claims 1, 2 or 3, being said final operations finishing and
adjusting operations, respectively finishing the shape,
calibration, annealing and superficial finishes, that are performed
in a way that is well known by those skilled in the art of
ammunition manufacturing; being said manufacturing process
characterized by the fact that the manufacturing sequence comprises
the following successive steps: generation of a cylinder blank of
proper weight and diameter by means of cutting, sawing or shearing
a wire or rod of suitable material, preferably copper or a copper
alloy; cold forming by one or more strokes with punches of single
or progressive circular or polyhedric cross-section hitting the
cylinder blank positioned in a die, totally or progressively
creating a preliminary internal cavity without altering the
external cylindrical shape of the metal piece; execution of a
plurality of grooves or slits and preliminary shaping of the fore
portion of the projectile, thus modifying the radius of the cavity
obtained on step b above and reducing this radius by at least 7%,
and modifying the shape of the preliminary internal cavity by
displacement of the main diameter from the front end to a position
between the front end and the bottom of the cavity.
Description
BACKGROUND OF THE INVENTION
[0001] It is recognized today that the use of lead or other toxic
material in a bullet constitutes a great nuisance for the
environment and the user, and must therefore be avoided.
[0002] It is also well know that projectiles, particularly those
used in police operations or personal defense, must feature a high
capability for stopping an attacker at once, without traversing the
target and thus perhaps wounding other people. That is particularly
important when the use of said ammunition is considered under
extreme situations, such as those involving life risk for the
police officer, an innocent pedestrian, etc.
[0003] These projectiles, used in police operations, must be able
to pass through tactical obstacles that offer protection to the
criminal such as vehicle doors or windscreen. However, the
projectile must be able to do it without changing it's trajectory,
lest there is serious risk of injuring innocent people which are
not being targeted by police action.
DESCRIPTION OF RELATED ART
[0004] Projectiles deforming on impact have been known for a long
time, and were initially made of lead, usually with a hollow point.
Nowadays these projectiles are made of solid materials, and are
generally composed of two pieces, with the fore piece generally
made of plastic, or sometimes metal acting as a pusher to create
expansion. Examples of said projectiles in the state of the art can
be found on "REDUCED-CONTAMINANT DEFORMABLE, BULLET, PREFERABLY FOR
SMALL ARMS" by Knappworst et al. (WO 01/67030 A1); "SMALL-CALIBRE
DEFORMATION PROJECTILE AND A METHOD FOR THE PRODUCTION OF THE
SAME"--Baumgartner et al. (WO 01/88460 A1); "DEFORMATION
PROJECTILE"--Sigl et al. (WO 01/02791 A1); "Projectile Pour Armes a
Feu Notamment Pour Armes de Poing et armes a canon long"--A Dynamit
Nobel (FR 2369538); "Jacketless hunting bullet with roll-back
cutting flags"--A Avcin (U.S. Pat. No. 4,044,685); "Cartridge for
hand and shoulder firearms"--Schirnecker (U.S. Pat. No. 4,136,616
A); "DEFORMATION PROJECTILE"--DNAG (WO 01/02791 A2);
"PROJECTILE"--Winter (U.S. Pat. No. 5,160,805), "Projectile with
improved flowering"--Petrovich et al. (U.S. Pat. No.
5,185,495)).
[0005] Another type of solid monobloc projectile operation is based
on the internal geometry of the bullet cavity, which features a
shape resembling a star, or another specific geometry which
performs the same way. These can be found on "Methods of
manufacturing a bullet"--Brooks (U.S. Pat. No. 5,131,123) and
"Intermediate article used to form a bullet projectile or component
and a finally formed bullet"--Brooks (U.S. Pat. No. 5,259,320).
[0006] Another type of solid monobloc projectile is a single piece
solid, without cuts or cavities, generally for big game hunting,
featuring maximum penetration. Examples of these are found on
"Solid projectiles"--Lufty (U.S. Pat. No. 4,811,666) and
"Projectile"--Hatcher (U.S. Pat. No. 2,234,165). These projectiles
feature very little expansion.
[0007] Yet another type of solid monobloc projectile operates by
means of an internal cavity with a central pin or axis, being the
external portion of the bullet provided with grooves to generate
the targeted expansion. An example would be "EXPANSION
PROJECTILE"--Winter (WO 97/40334).
[0008] The Inventor chooses to make no comments here on the classic
hollow point projectiles composed of a core and a jacket, which lie
outside the scope of the present invention.
SUMMARY OF THE INVENTION
[0009] The present invention can be better understood by analyzing
the specification text along with the attached set of Figures, in
which:
[0010] FIG. 1a shows a typical example of a projectile described in
the present invention, which general external shape include a main
cylindrical portion, a front portion of generally ogival shape and
a rounded bottom portion, the same FIG. 1a is used to illustrate
the projectile's longitudinal section, with an internal cavity of
substantially elliptical shape. In this example, the largest
cross-sectional diameter is situated between the front open portion
of the projectile and the bottom of the internal cavity, being said
bottom a flat surface. This same FIG. 1a is used to illustrate one
of a plurality of external deformations with the form of grooves
that extend externally from the front end of the projectile. The
purpose of said plurality of grooves is to facilitate the expansion
or mushrooming of the projectile.
[0011] FIG. 1b shows a typical shape of an alternative projectile,
with a front portion of truncated conical shape, and a cavity with
a generally rounded bottom shape, being the remainder portions of
this projectile identical to their analogs of FIG. 1a. It is always
worth to remember that both FIG. 1a and FIG. 1b are given solely as
non-limitative examples.
[0012] FIG. 2a is a front view illustrating a typical projectile
with axially symmetrical shaped cavity (hexagonal shape in this
example).
[0013] FIG. 2b a front view illustrating a typical projectile with
axially symmetrical shaped cavity (hexagonal shape in this
example).
[0014] FIG. 3 shows a typical intermediate shape of a metal piece
illustrating its appearance after the first cold forming operations
of the manufacturing sequence with a typical example of cavity with
a cylindrical portion, a generally conical/elliptical portion and a
generally flat bottom portion.
[0015] FIG. 4 illustrates parts of a typical manufacturing
sequence, showing successively:
[0016] Copper or copper alloy cylinder after cutting a wire or rod;
copper or copper alloy piece after first cold deformations; initial
projectile ogive or conical fore portion forming and external
grooves forming; final fore portion forming; the calibration,
annealing, and surface finishing do not change the general form of
the bullet.
[0017] It is worth observing that all shapes and geometries
described herein refer to both the internal and external
geometries.
[0018] One of the objects of the present invention is to disclose a
projectile that easily and quickly deforms upon expansion after
penetrating soft targets, generating an expansion of at least 40%
compared to the puncture diameter measured on the initial impact
surface, with no loss of original weight, no breakage of the
projectile, performing a fast transfer of energy in the early
portion of the trajectory inside the soft environment, and avoiding
unintentional hits on secondary targets.
[0019] Another object of the present invention is a projectile that
easily perforates hard targets without breaking or changing its
trajectory.
[0020] Another object of the present invention is a projectile that
contains no lead or other hazardous material.
[0021] Another object of the present invention is a projectile
which homogenous construction allows high performance in the aspect
of accuracy.
[0022] Yet another object of the present invention is a projectile
easy to manufacture at a reasonable cost, with existing
manufacturing tools and technology.
[0023] The present invention applies to any handgun, rifle or
shotgun ammunition; when used in smoothbores, the essential
stability of the bullet is achieved by positioning the center of
gravity ahead of the aerodynamic center.
[0024] The present invention attains the objects described above
through the combination of characteristics which are discussed in
the following paragraphs.
[0025] Material:
[0026] The present invention discloses a solid projectile (made of
one single piece) of a material which density preferably ranges
from 6 to 10. Said material is preferably copper or a copper alloy,
with a Vickers hardness preferably ranging from 40 to 70.
[0027] Internal Cavity:
[0028] The projectile features an internal cavity centered
regarding the longitudinal axis of construction. The longitudinal
section of said cavity preferably presents a generally elliptical
shape, with or without a cylindrical portion interspersed. In order
to describe the shape of said internal cavity, the Inventor chose
to use a radial coordinate system, in which (r) is the radius of a
circumference which is normal to the longitudinal axis of the
projectile and (d) is the abscise of a generic point which lies in
said longitudinal axis of the projectile. The various values
assumed by (d, r) describe successive circumferences (all of them
normal to the longitudinal axis of the projectile) which make up
the perimeter of the internal cavity. The origin adopted for said
coordinates system is the point of the longitudinal axis of the
projectile which lies in the same plan that contains the forward
most section of the projectile (i.e. the front end of the
projectile, where d=0).
[0029] For instance, the maximum value of (d) corresponds to the
bottom of the internal cavity.
[0030] The ideal proportions for the internal cavity of the
projectile of the present invention are defined regarding the
caliber of said projectile, being the caliber defined by the
diameter of the cylindrical portion of the projectile:
[0031] the maximum value of r is situated between the positions
where the value of d=0 and d=d.sub.maximum;
[0032] said radius r decreases progressively towards the front end
where d=0;
[0033] said radius r decreases progressively towards the bottom of
the cavity where d=d.sub.maximum;
[0034] where d=0 (front end of the projectile) said radius r ranges
from 10% to 40% of the caliber of said projectile;
[0035] the maximum value of said radius r of said internal cavity
ranges from 10% to 40% of the caliber of the projectile;
[0036] where d=d.sub.maximum (bottom of the cavity) said radius r
ranges from 0 (flat surface) to 35% of the caliber of said
projectile (rounded bottom);
[0037] d.sub.maximum ranges from 0.50 to 2.5 times the caliber of
said projectile;
[0038] the transversal and longitudinal cross-sections of said
cavity present radial symmetry regarding the longitudinal axis of
said projectile, being said cavity cross-section of a circular or
other regular geometrical figure shape.
[0039] External Grooves:
[0040] The projectile of the present invention features a plurality
of grooves, slits or other geometrical forms that extent
longitudinally over the external face of the projectile. The
purpose of said plurality of grooves is to facilitate the opening
of the projectile and avoid breaking. The number of grooves or
slits preferably ranges from 3 to 9. The cross section of said
grooves is preferably of a generally triangular shape, and their
length is preferably superior to 5% of the length of the internal
cavity.
[0041] Said grooves or slits extend from near the front end of the
projectile to a maximum length where the cross-section where is
located the crimping or the case mouth. Let us remember that the
bullet is mounted to a case containing propulsive powder and
primer, being said case crimped to the bullet in order to hold it
in place, and said crimping forming a generatrice on the
cylindrical portion of the bullet.
[0042] Bottom Portion of the Cavity:
[0043] The bottom portion of the central cavity is either a
three-dimensional rounded end or a plan surface with circular
perimeter, that being described by the values of (r, d) for the
region of the bottom of the cavity.
[0044] These characteristics of solid monobloc construction,
suitable material and hardness (copper or copper alloy and final
annealing to obtain a Vickers hardness of 40 to 70), geometry of
the internal cavity and the external grooves are responsible for
the outstanding performance of the present invention. The bullet
will nor break, even upon hitting hard targets such as a safety
glass or multiple sheets of steel; the bullet will rapidly mushroom
or expand and thus is able to generate a rapid transfer of energy
into soft targets.
[0045] Manufacturing Sequence
[0046] The bullet of the present invention can be constructed
following this general manufacture sequence:
[0047] a) Cutting of a proper cylinder blank, preferably by
cutting, sawing or shearing a wire or rod of suitable material,
such as copper or copper alloy.
[0048] b) Cold forming of a preliminary internal cavity centered on
the longitudinal axis of said cylinder blank, were the geometry of
said cavity is roughly equal to that of a cylinder in which the
radius varies a little along certain portions of its length. Said
preliminary internal cavity may or may not include a portion of
pure cylindrical shape (r=constant), and the bottom of said
cylinder may correspond to a section of a sphere (r progressively
diminishing towards the bottom of the cavity) or a sheer plan
surface (r abruptly made=0). The shaping of the preliminary
internal cavity is controlled by simply varying the values of (r,
d) of the punch used in the cold forming according to the desired
shape of the cavity. Said cold forming involves one or more strikes
of suitable punches on the chosen end of the cylinder blank
obtained on the previous cutting step creating a deformation
axially symmetrical to the longitudinal axis of said cylinder
blank, said obtained final deformation forming a preliminary
internal cavity presenting a larger radius r toward the front end
of the projectile where d=0 is zero, with the radius r of said
internal cavity varying preferably as:
[0049] the maximum value of radius r of said internal cavity is
situated where d=0, ranging preferably from 95% to 70% of the
radius of said cylinder blank;
[0050] With a cylindrical portion, situated between the front end
and the bottom of the cavity, the length of said cylindrical
portion ranging from zero to twice the diameter of said cylinder
blank;
[0051] The radius r of said internal cavity decreasing from where
d=0 to d=d.sub.maximum where the radius r ranges from 35% of the
diameter of said cylinder blank to r=0;
[0052] The maximum value of d ranges from 0.50 to 2.5 times the
diameter of said cylinder blank;
[0053] c) Formation of the external deformations of the form of
grooves, preferably by pressure applied with the appropriate tool
or die.
[0054] d) Shaping of the end of the ogival nose portion;
[0055] e) Calibration of the caliber diameter, made by forcing the
projectile through a cylindrical cavity tool;
[0056] f) Annealing to the suitable hardness, if necessary;
[0057] g) Application of a superficial finish such as polishing
(preferably by trammeling), plating with a suitable material,
covering (preferably by spraying or dipping in a suitable polymeric
material), etc.
[0058] Those skilled in the art will realize that the operations
encompassed on steps c) to g) can be performed using methods
belonging to the current state of the art, and that the description
of one or more of the preferential incorporations of the present
invention does not limit its scope of application, which is in fact
limited only by the set as defined in claims attached herein.
* * * * *