U.S. patent application number 12/171487 was filed with the patent office on 2009-01-15 for casing for soft projectile and method for making same.
This patent application is currently assigned to SJS PAINTBALL, LP. Invention is credited to Paul Judson, Robert Judson.
Application Number | 20090013892 12/171487 |
Document ID | / |
Family ID | 40252044 |
Filed Date | 2009-01-15 |
United States Patent
Application |
20090013892 |
Kind Code |
A1 |
Judson; Robert ; et
al. |
January 15, 2009 |
CASING FOR SOFT PROJECTILE AND METHOD FOR MAKING SAME
Abstract
A casing for a relatively soft projectile, such as a projectile
for a paintball gun, has a concave portion for receiving a
substantially round soft projectile, a driving band located behind
the concave portion, and an aerodynamic portion located behind the
driving band. The driving band preferably has lands and grooves for
engaging rifling in the bore of the gun. The aerodynamic portion
may have the approximate shape of a prolate spheroid or a
paraboloid of revolution, or another shape that reduces eddy
currents and drag behind the projectile. The concave portion of the
casing preferably has an adhesive to prevent separation of the
casing and projectile in flight. The casing may be solid or hollow;
in the later case, it may be filled with a substance such as
urethane foam.
Inventors: |
Judson; Robert; (Richardson,
TX) ; Judson; Paul; (Richardson, TX) |
Correspondence
Address: |
Glast, Phillips & Murray, P.C
13355 Noel Road, Suite 2200
Dallas
TX
75240
US
|
Assignee: |
SJS PAINTBALL, LP
Richardson
TX
|
Family ID: |
40252044 |
Appl. No.: |
12/171487 |
Filed: |
July 11, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60959073 |
Jul 11, 2007 |
|
|
|
Current U.S.
Class: |
102/502 |
Current CPC
Class: |
F42B 12/76 20130101;
F42B 10/26 20130101; F42B 10/44 20130101; F42B 12/40 20130101 |
Class at
Publication: |
102/502 |
International
Class: |
F42B 30/00 20060101
F42B030/00 |
Claims
1. A casing for a soft projectile comprising: a concave portion for
receiving a substantially round soft projectile; a driving band
located behind the concave portion; and, an aerodynamic portion
located behind the driving band.
2. The casing of claim 1, where the driving band has lands and
grooves for engaging rifling.
3. The casing of claim 1, where the aerodynamic portion has
approximately the shape of a section of a prolate spheroid.
4. The casing of claim 1, where the aerodynamic portion has
approximately the shape of a section of a paraboloid of
revolution.
5. The casing of claim 1, where the aerodynamic portion has
approximately the shape of a cone.
6. The casing of claim 1, where the aerodynamic portion has
approximately the shape of a truncated cone.
7. The casing of claim 1, where the casing has a hollow inside.
8. The casing of claim 1, further comprising: a substance filling
the inside of the casing.
9. The casing of claim 1, further comprising: an adhesive located
in the concave portion, for adhering the soft projectile to the
casing.
10. A casing for a soft projectile, comprising: a concave portion
for receiving a substantially round soft projectile; a driving band
located behind the concave portion; and, the casing having a flat
surface immediately behind the driving band.
11. The casing of claim 10, where the driving band has lands and
grooves for engaging rifling.
12. The casing of claim 10, where the casing has a hollow
inside.
13. The casing of claim 10, further comprising: a substance filling
the inside of the casing.
14. The casing of claim 10, further comprising: an adhesive located
in the concave portion, for adhering the soft projectile to the
casing.
15. A casing for a soft projectile comprising: a concave portion
for receiving a substantially round soft projectile; an adhesive
located in the concave portion, for adhering the soft projectile to
the casing; a driving band located behind the concave portion; the
driving band having lands and grooves for engaging rifling; an
aerodynamic portion located behind the driving band; the
aerodynamic portion having approximately the shape of a section of
a prolate spheroid; the casing having a hollow inside; and, a
substance filling the inside of the casing.
16. A casing for a soft projectile comprising: a concave portion
for receiving a substantially round soft projectile; an adhesive
located in the concave portion, for adhering the soft projectile to
the casing; a driving band located behind the concave portion; the
driving band having lands and grooves for engaging rifling; an
aerodynamic portion located behind the driving band; the
aerodynamic portion having approximately the shape of a section of
a prolate spheroid.
Description
CLAIM FOR PRIORITY
[0001] This application claims the priority of U.S. Provisional
Patent Application Ser. No. 60/959,073, titled "Casing for Pliable
Soft-Projectile and Method for Making Same," filed Jul. 11, 2007,
which application is incorporated by reference into the present
application.
INCORPORATION BY REFERENCE
[0002] This application incorporates by reference the disclosure of
U.S. Patent Publication No. 2005/0247295, titled "Barrel and ball
sizer for paint-ball gun," published Nov. 10, 2005; and further
incorporates by reference U.S. patent application Ser. No.
12/164,877, titled "Soft-Projectile Gun Barrel and Method for
Making Same," filed Jul. 2, 2008.
BACKGROUND
[0003] This disclosure relates to guns that propel projectiles
using compressed gas as a propellant. More particularly, it relates
to an improved projectile for use in combination with a gas powered
projectile gun firing soft or pliable ammunition such as paint
balls or pepper balls. Paint balls have a liquid center covered by
a thin plastic or gelatin membrane that maintains the paint ball in
an approximately spherical shape. Pepperballs have a powder filled
center covered by a thin, relatively harder, plastic shell, but
still accurately described as "soft" projectiles.
DRAWINGS
[0004] FIG. 1 depicts a casing for a soft projectile.
[0005] FIG. 2 depicts another embodiment of a casing for a soft
projectile.
[0006] FIG. 3 depicts details of the combination of a casing and a
soft projectile and other embodiments. The casing is also shown in
cross-section.
DESCRIPTION
[0007] In large-caliber, high-velocity guns there is some risk of
the shock of impact with the rifling "stripping" the driving band
of the shell. To combat this, some weapons have progressive
rifling, in which the rifling grooves start out parallel then
gradually increase in twist down the barrel. In barrels for
soft-projectile guns, the relationship between the mass and size of
the projectile and the propellant force is similar to that in
conventional high-velocity cannon. We have found that because of
this relationship, the driving-band feature may be adapted to
low-velocity soft-projectile guns.
[0008] A gun for firing the projectile casing (110) disclosed here
preferably has progressive rifling (120) to cause the rotation of
the liquid or powder center of the ball (100) to match the rotation
of the outer membrane as the ball leaves the gun barrel. This
results in enhanced ball stabilization against tumbling and drift
in flight, leading to longer flights and improved accuracy. In
other embodiments using the same methods for making, however, the
rifling of the bore could be non-progressive, or the lands and
grooves on the driving band (115) of the casing (110) could be
eliminated, so that a smooth casing (110) engages rifling in the
barrel.
[0009] A further advantage of the casing (110) is that it can
improve the aerodynamics of the projectile over those of a
conventional spherical ball (100), resulting in reduced drag due to
eddy currents. This allows for longer flights of the ball (100),
with improved accuracy.
[0010] FIG. 1A shows a casing (110) of the preferred embodiment.
The casing (110) has a concave portion (130) for receiving the
substantially round projectile (100). The driving band portion
(115) of the casing (110) has rifling (120), comprising grooves and
lands integral with the driving band portion (115). FIG. 1B shows a
rifled casing (110) with a projectile (100) inserted into it. In
FIGS. 1A and 1B, the casing has an aerodynamic portion (160). The
aerodynamic portion (160), as shown in the figures, preferably has
the shape of a section of a prolate spheroid or a paraboloid of
revolution; as commonly stated, an "egg-shape."
[0011] FIG. 2 shows another embodiment of the casing (110). Here,
the casing (110) has no aerodynamic portion on its rear, only a
flat surface (135) immediately behind the driving band (115). FIG.
2A shows an adhesive (150), such as cyanoacrylic glue, in the
casing (110), to adhere to the projectile (100), so that the
projectile (100) is not released from the casing (110) when it
exits the bore of the gun. The adhesive (150) could of course also
be applied in the other embodiments illustrated in FIGS. 1 and
3.
[0012] FIG. 3 shows different embodiments of the casing (110). FIG.
3A shows a cross-section of a casing (110) without an aerodynamic
appendage (160), as in FIG. 2. In FIG. 3, the casing (110) is shown
as hollow, and the inside of the casing (110) is preferably filled
with a substance (140) to increase the solidity of the casing (110)
and projectile (100) combination. The substance (140) could be
urethane foam or a similar plastic. Alternatively, it is possible
for the casing (110) to be manufactured as a solid object. FIGS. 3B
and 3C show other embodiments having aerodynamic portions (160).
FIG. 3B shows a cone shape, and FIG. 3C shows a truncated cone
shape for the aerodynamic portion (160) of the casing (110).
[0013] We have found that the combination of projectile (100) and
casing (110) disclosed will quickly align with and engage the
rifling of a barrel, so as to impart a spin to the projectile
(100). This will be so in other embodiments where the casing (110)
lacks lands and grooves, although not as efficiently.
[0014] The disclosed casing (110) can be constructed by molding
from a cast made from a rifled barrel, or from a cast machined for
this purpose. Alternatively, the casing could be formed by plastic
extrusion. Suitable materials for the casing are most
thermoplastics, such as polyurethane, polycarbonates, such as
LEXAN, from the GE Plastics Company, acrylics, or ABS varieties.
Reinforcing materials could be added to the thermoplastic,
Reinforcing materials may include powdered metals such as aluminum
or iron, carbon fibers, or fiberglass. An example of such a casting
process for rifling is disclosed in the incorporated U.S. patent
application Ser. No. 12/164,877.
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