US20050235547A1

US20050235547A1 - 9.3 mm Blank cartridge and chamber

Info

Publication number: US20050235547A1
Application number: US11/114,494
Authority: US
Inventors: Charles Ducastel
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-04-27
Filing date: 2005-04-26
Publication date: 2005-10-27

Abstract

A chamber and blank cartridge of specific dimensions for safer use in simulated firearms. The dimensions of the chamber make it incompatible for use with known lethal cartridges. The dimensions of the blank cartridge make it incompatible with the chambers of actual firearms. This prevents the inadvertent loading of lethal or blank cartridges. Upon discharge the blank cartridge and chamber release exhaust gases in a forward direction. This effect is similar to an actual firearm and so generates realistic visual and auditory effects. The blank cartridge has a nose which may increase propellant capacity. The use of additional propellant will generate greater energy for visual and auditory effects. This will also improves the cycling of actions of larger simulated automatic firearms. The shape of the nose also improves magazine feeding in automatic simulated firearms.

Description

BACKGROUND OF THE INVENTION—PRIOR ART

Blank cartridges are used to simulate the visual and auditory effects of actual firearm cartridges. Blank cartridges include a case but not a projectile. The lack of a projectile permits blank cartridges to be used safely for training, theatrical, educational, and recreational purposes.
Blank cartridges operate in a manner common to cartridges generally. A blank cartridge is slidably inserted into a chamber of corresponding internal dimensions. The bolt is closed, seating the cartridge upon the case neck, case mouth, case shoulder, or case rim. A striker is forwardly released through the bolt face to impact and detonate the primer. The resulting flash is ported through one or more flash paths to the interior of the cartridge. The propellant ignites and generates pressurized exhaust gases. The exhaust gases are vented from the cartridge and exit through the chamber.
A cartridge, whether blank or lethal, may be used only in a chamber of mated physical dimensions. If the cartridge does not mate within the chamber, it will not seat and not be capable of discharging. This limits the cartridges that a firearm may be capable of chambering, and prevents incorrect and possibly unsafe cartridges from being discharged.
There are two main types of blank cartridges. One type has exterior dimensions compatible with the chambers of actual firearms. These may be used in actual firearms alternatively with lethal cartridges. This type of blank cartridge vents the exhaust gases in a forward direction, like lethal cartridges. This generates realistic visual and auditory effects. Yet the use of such cartridge always incurs the risk that a lethal cartridge may be inadvertently chambered. Discharge of the lethal cartridge could cause serious damage, injury, or death.
The second type of blank cartridge is incompatible for use in actual firearms. These blank cartridges have external dimensions compatible only with the chambers of simulated firearms. An example is the 8 mm blank cartridge and chamber used with simulated handguns. This blank cartridge is illustrated by FIG. 1. This blank cartridge has flat nose which is unlike a conical bullet of a typical lethal cartridge. The 8 mm blank cartridge and chamber also operate in an unconventional manner. Exhaust gases are ported from the blank cartridge in a direction perpendicular to the axis of the blank cartridge. The gases escape from the chamber and exit the firearm in a similar perpendicular direction. Since no gas escapes from the muzzle, the visual and auditory effects are not realistic. The flat nose also limits the internal capacity for propellant, reducing possible visual and auditory effects. This limited propellant capacity also reduces the energy for cycling the actions of larger automatic simulated firearms, such as machine guns. The external profile of the flat nose is unlike that of most lethal cartridges which have conical projectiles. The flat nose can cause feeding problems when used in the magazines of automatic simulated firearms. Finally, cartridges in unconventional chambering are expensive to manufacture due to limited production.

BACKGROUND OF THE INVENTION—OBJECTS AND ADVANTAGES

Accordingly, there are several objects and advantage of the present invention. First, the blank cartridge is incompatible with the chambers of actual firearms. The dimensions of the blank cartridge prevent it from chambering and seating in actual firearm chambers. Second, the chamber dimensions make it incompatible with known lethal cartridges. This prevents lethal cartridges from being inadvertently loaded into the chamber. Third, the blank cartridge and chamber port exhaust gases in a forward direction, producing more realistic visual and auditory effects. Fourth, the cavity created by the nose provides greater capacity for propellant. This allows increased muzzle flash and report. Additional propellant also allows the cartridge to cycle more massive actions of larger simulated automatic firearms. A fifth advantage is that the blank cartridge case can be manufactured from brass stock in the common 5.56 mm×54 mm chambering. This reduces manufacturing costs. Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.

SUMMARY

In accordance with the invention, a chamber of unique dimensions for use in simulated firearms, and a mating blank cartridge with a base, a case wall, a case shoulder, and a nose extending from the case shoulder and enclosing the cartridge.

DRAWINGS—FIGURES

An embodiment of the invention will now be described with reference to the following diagrammatic drawings in which:
FIG. 1 shows a side view of the prior art 8 mm blank cartridge.
FIG. 2 shows a sectional view of a chamber of the present invention.
FIG. 3 shows a side view of a blank cartridge of the present invention.
FIG. 4 shows a sectional view taken along line 4-4 of FIG. 3.

DRAWINGS—REFERENCE NUMERALS

- 8 primer
- 10 base
- 20 case wall
- 30 case shoulder
- 40 crimp
- 50 nose
- 60 propellant
- 70 flash path
- 100 chamber
- 120 chamber base
- 140 chamber neck
- 150 chamber length
- 160 chamber diameter

DESCRIPTION—REFERRED EMBODIMENT—FIGS. 1-4

Prior Art—FIG. 1
An example of a prior art 8mm blank cartridge is shown by FIG. 1. This blank cartridge has a base 10, case wall 20, and a case shoulder 30. This blank cartridge has a nose 50. The nose 50 is flat and extends approximately at a right angle to the case wall 20.
A preferred embodiment of the chamber of the present invention is illustrated in FIG. 2. FIG. 2 shows the chamber in cross-sectional view. The chamber 100 has a chamber base 120 and chamber neck 140 for mating the blank cartridge of FIG. 3. The chamber length 150 and chamber diameter 160 are also dimensioned to mate the blank cartridge of FIG. 3. The chamber length 150 is approximately 19.4 mm. The chamber diameter 160 is approximately 10.0 mm. The internal diameter of the chamber neck 140 is approximately 8.4 mm.
Referring to FIG. 3, there is shown a side view of the blank cartridge 80. The blank cartridge 80 has a base 10 and case wall 20. The case wall 20 tapers with a reverse radius to the nose 50. The crimp 40 extends circumferentially at the juncture of the case wall 20 and nose 50. The crimp 40 forms the case shoulder 30. Dimensionally the external diameter of the base 10 is approximately 9.6 mm. The external diameter of the case wall 20 at the juncture with the case shoulder 30 is approximately 8.2 mm. The length from the base 10 to the case shoulder 30 is approximately 19.0 mm.
Referring to FIG. 4, there is shown a cross-sectional view of the blank cartridge of FIG. 3. The primer 8 is attached to the base 10. A flash path 70 extends from the primer 8 through the base 10. One flash path 70 is shown in FIG. 4, although more than one could be present. The propellant 60 is contained by cavity defined by the base 10, case wall 20, and nose 50. The volume of propellant 60 could vary in other embodiments from that shown in FIG. 4.

Operation—Preferred Embodiment—FIGS.

The manner of using the blank cartridge and chamber is identical to those in current use. The blank cartridge of FIG. 3 is loaded into the chamber 100 of a simulated firearm. Upon firing, the primer 8 is detonated in a conventional manner. Exhaust gases are ported through the flash path 70 to ignite the propellant 60. This produces pressurized exhaust gases which outwardly expand the nose 50. The exhaust gases escape through forward end of the chamber 100 and exit the simulated firearm.
Advantages
From the description above, a number of advantages of my blank cartridge and chamber become evident:

- (a) The chamber is dimensionally incompatible with known lethal cartridges, such that lethal cartridges will not chamber or seat if inadvertently loaded.
- (b) The blank cartridge is dimensionally incompatible with the chambers of actual firearms, such that the blank cartridge will not chamber if inadvertently loaded into an actual firearm.
- (c) Exhaust gases are released from the blank cartridge and chamber in a forward direction, producing more realistic visual and auditory effects.
- (d) The nose 50 provides the cartridge with an exterior shape similar to that of a lethal cartridge, permitting more reliable feeding from the magazines of some types of simulated automatic weapons.
- (e) The cavity defined by the base 10, case wall 20, and nose 50 provides the cartridge with an increased capacity for propellant to produce greater visual and auditory effects, and generate more energy for cycling the actions of larger simulated automatic firearms.
- (f) The blank cartridge dimensions are such that it may be manufactured from stock 5.56 mm×54 mm brass.

Conclusion, Ramifications, and Scope

Accordingly, the reader will see that, according to the invention, I have provided a blank cartridge and chamber for safer use in simulated firearms. The blank chamber is incompatible with lethal cartridges. Similarly, the blank cartridge is incompatible with the actual firearm chambers. The blank cartridge and chamber port exhaust gases in a realistic forward direction. The use of a nose provides better feeding from the magazines of simulated automatic firearms. The propellant capacity added by the nose allows greater visual and auditory effects. This increased propellant capacity can also generate more energy for cycling the actions of actions of larger simulated firearms, such as machine guns.
While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but as exemplifications of the presently preferred embodiments thereof. Many other ramifications and variations are possible within the teachings of the invention. For example, a circumferential crimp around the case wall 20 could be used or omitted. The case shoulder 30 may have a diameter smaller than 8.2 mm. The blank cartridge may be composed of brass or a different material. Some components such as the case wall 20, case shoulder 30, or nose 50 could be composed of plastic, like a shotgun shell. The primer 8 could a small rifle or pistol primer. The blank cartridge may have one or more flash paths. The chamber wall could be straight, fluted, and or lined.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, and not by the examples given.

Claims

1. A chamber for a blank cartridge for use in simulated firearms, comprising a chamber base, a neck, and said chamber having the following dimensions

diameter of said chamber base at the about 10.0 mm commencement of said chamber base length of said chamber base about 19.4 mm diameter of said chamber neck about 8.4 mm

2. A blank cartridge, comprising a base, a case wall extending from said base, with said case wall having a diameter with a reverse taper, a case shoulder at the end of said case wall, and a nose extending from the case shoulder and enclosing the blank cartridge; and said blank cartridge having the following dimensions:

diameter of said base about 9.6 mm diameter of said case wall at the juncture of about 9.3 mm said case wall and said case shoulder diameter of said case shoulder about 8.2 mm length from said base to said case shoulder about 19.0 mm

3. A cartridge as defined in claim 2, wherein said blank cartridge having a primer.

4. A cartridge as defined in claim 2, wherein said blank cartridge containing propellant.

5. A cartridge as defined in claim 2, wherein said blank cartridge having a primer and containing propellant.

6. A cartridge as defined in claim 2, wherein said case shoulder having a diameter of less than 8.2 mm.

7. A cartridge as defined in claim 6, wherein said blank cartridge having a primer.

8. A cartridge as defined in claim 6, wherein said blank cartridge containing propellant.

9. A cartridge as defined in claim 6, wherein said blank cartridge having a primer and containing propellant.