DUMMY CARTRIDGE

FAUSSE CARTOUCHE

English Abstract

Title of the invention



DUMMY CARTRIDGE




Abstract of the disclosure

The purpose of the present invention is to
provide a dummy cartridge warranting a greater safety in use.
This has been achieved by a cartridge made substantially from
plastic and wherein the internal cavity of the projectile portion
in an axial plane has a marked conical form having an elliptic
or irregular polygonal cross section, whereas the projectile
portion externally is provided with opposite slanting surfaces
and the shell portion has a rough surface.
As a result of the described internal form
the projectile portion will split open by the gun powder gasses
from the explosion and be pressed on two sides against the wall
of the bore without any fragments or cartridge portions being
thrown out.

Claims

C 1 a i m s

1. A dummy cartridge substantially made from
plastic material, c h a r a c t e r i z e d in that the
internal cavity of the projectile portion in an axial plane
has a marked conical form having an elliptic or irregular
polygonal cross section, whereas the projectile portion exter-
nally is provided with opposite slanting surfaces, and the
shell portion has a rough surface.
2. A dummy cartridge according to claim 1,
c h a r a c t e r i z e d in that the external opposite
slanting surfaces of the projectile portion are converging
towards a plane comprising the longest axis of the internal
cross section form.

Description

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The present invention is related to a dummy
cartridge which is substantially made'from plastic material
and wherein the radially active forces from the gun powder gasses ,
are used to open (split open) the projectile poxtion of .
the cartridge. It is a main purpose of the invention to ~.:
reduce the axial tensile forces internally of the cartridge '
because these will be a substantial contributing aause of
the'separation and consequent.discharging of plastic--frag- '~
ments and/or portions of the cartridge. . '~ ,
According to the invention the said purpose .:~
has been achieved by providing the internal cavity of the
projectile portion in an axial plane with a marked conical
form having an elliptic or irregular polygonal cross section, ~:
whereas the projectile portion externally.is provided with
opposite slantlng surfaces and the.shell portion has a rough :
surface. It is also a feature of the invention that the .-
external OppOSite slanting surfaces of the projectile portion '
are converglng towards a plane comprlsing the longest axis~
of the lnternal cross sectional forms~ ~-
The external dimensions of the cartridges
being dependant of the chamber of the varlous guns, the
differences ln relation to live ammunition is limited to
the surface fineness of the shell and external and internal
form of the projectile portion.
The invention.will be more-fully understood from -'
the following description-with reference to the drawings,
wherein
Fig. 1 is showi.,ng the internal form of the
projectile portion in the first axial plane,

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Fig. 2 is showing the cross section of the
internal cavity àlong the line II-II in Fig. 1,
Fig. 3 is showing the outer form of the projectile
portion with the opposite slanting surface,
Fig. 3a is an end view of same projectile portion
seen from ~he tip of the projectile,
Fig. 4 is an axial sectional view of the pro-
jectile portion in a plane at right angle to the sectional plane
of Fig. 1, and
Fig. 5 is showing the projectile portion in
position in the chamber and bore of the gun.
As will be seen from Fig. 1 the internal form
of the projectile portion in one axial plane has been given
à marked conical form, whereas Fig. 2 is showing the internal
cross section of the projectile, which in the embodiment ~ -
shown has the form of a somewhat flattened ellipse, but
is not dependant of this particular form. By this cross
sectional form two strengthened ridges 1 will be ~ormed in
the wa-lis of the projectile portion. ~he projectile portion
is externally provided with opposite slanting surfaces 2
.
as best shown in Fig. 3 and 3a and said strengthened ridges l
are oriented towards the two external surfaces 2.
As a result of the described and shown internal
form of he projectile portion the gunpowder gasses will by
explosive glve a relatively great pressure against the ridges
which are th~s pressed against the walls of the bore in a
radial direction as lndicated with the arrows 3 in Fig. 5.
Owing to the tensile forces occuring in radial direction
the material of the projectile wall 4 ~see Fig.s 2 and 4)
being 90 angularly displaced in relation to the external
surfaces will arrive at its breaking strength, whereby opening
of the projectile portlon wil~l take place.
The external surfaces 2 are of essential importance
to give space allowing the intended deformation during opening
of the projectile portion in the boxe, at the same time as
said surfaces are providing the projectile portion with
necessary elasticity. Said rough surface 5 of the conical


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shell will have a dampening effect even on forces in an
axial direction.
The tip of the projectile is designed for
opening in a radial direction in order to avoid axial
load.


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