CA1053073A - Dummy cartridge - Google Patents

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.

Description

1~3073 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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l~S3073 ' ' ' 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 , / . .

~C1iS3~)73 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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Claims (2)

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.