Not Applicable
Not Applicable
1. Field of the Invention
The invention relates to the field of firearms. More specifically, the invention comprises a token that is affixed to the base of a cartridge so that the modified cartridge can only be fired in a specially-configured firearm.
2. Description of Related Art
The present invention provides a firearm cartridge that is configured to be fired only in a specially-modified firearm. Such an invention is preferably adapted for use in a wide variety of firearms, including centerfire shotguns, rifles, and pistols. The invention may also be used with many other devices that use an explosive charge to launch a projectile, including less-lethal/non-lethal weapon systems (such as systems used for crowd control). The invention is particularly suited for use with firearms in which a bolt is moved in a direction that is parallel to the weapon's barrel bore. In such a firearm the round is loaded by the bolt moving forward (as opposed to break-action designs). Such bolts are found in pump-action shotguns, semi-automatic shotguns, slide-action rifles, bolt-action rifles, semi-automatic/automatic rifles, and semi-automatic/automatic pistols. The illustrations in this disclosure focus on pump-action shotguns, as this type of weapon is widely used in the law-enforcement community. However, the reader should bear in mind that the invention may be used in other types of weapons and non-weapon launchers as well.
In some cases a firearm's, bolt may combine both linear and rotary motion. As those skilled in the art will know, bolt-action rifles based on the inventions of Paul Mauser (such as the “Mauser '98”) employ a linear motion to load the cartridge and a rotary motion to lock the breech closed. An invention in this field preferably accounts for this type of combined motion as well.
As those skilled in the art will know, breech bolt 10 must be locked in the closed position before the weapon can be fired (It is true that some weapons fire from an open bolt, but this is the exception and such a configuration is not shown in the views). Locking toggle passage 14 passes through breech bolt 10 from top to bottom. Locking toggle 12 resides in this passage. Locking toggle 12 is employed to secure breach bolt 10 in the closed position and to perform other functions.
Extractor 20 is also connected to breech bolt 10. This claw-like component engages the rim on the base of a cartridge and pulls the cartridge out of the firing chamber when the bolt is moved rearward toward the open position. Other conventional features are also included in the bolt assembly. As these are well understood by those skilled in the art, they have not been depicted or described in more detail.
Propellant 50 is retained within wall 46 forward of the base wad. As those skilled in the art will know, when a firing pin strikes primer 36 the primer shoots burning gas into propellant 50 and ignites the shell. The burning propellant then forces the shot cup and shot down the bore and out of the weapon.
The shotgun shell construction shown in
Centerfire firearm cartridges (such as shotgun shells) have traditionally been thought of as a “lethal force” device, meaning that they possess the ability to kill a human or animal target. Even when smaller shot sizes are used (#7 and higher) a shotgun shell has the capacity to kill at close range. Now, however, non-lethal, and “less-lethal” cartridges have been developed for crowd control and other purposes. As an example, some shotgun, shells employ soft projectiles and other means to deliver a stunning blow without the potential for the creation of a fatal wound. These cartridges may be generally referred to as “less-lethal cartridges.”
Less-lethal cartridges are currently fired from the same firearms used for lethal cartridges and this fact has created unintended results. In a situation where an individual or crowd of individuals must be engaged and subdued, police officers are acting quickly and in a heightened emotional state. In such a situation it is possible for an officer to accidentally load a lethal shotgun cartridge instead of the less-lethal cartridge he or she intended to load. The mistake may not be discovered until the weapon is fired.
It is desirable to provide a cartridge and weapon system for delivering a less-lethal/non-lethal blow that prevents the accidental use of a lethal cartridge. The present invention provides such a solution.
The present invention comprises a firearm cartridge with a specially-configured token disc added to its base. The token includes an outer section and a central strike plate. The strike plate includes a strike ball at its center. The presence of the token increases the effective length of the cartridge and thereby prevents the closure of the bolt of a conventional firearm. As a result, the inventive cartridge cannot be fired in a conventional firearm.
A conventional firearm may be modified to fire the inventive cartridge by relieving a substantial part of the bolt face so that the bolt face receives the token disc. The firing pin of such a modified firearm must also be shortened. As a result, a firearm modified to use the inventive cartridge cannot fire a conventional cartridge. The result is a cartridge which can only be fired in a modified firearm, and a modified firearm which can only fire the inventive cartridge.
The present invention may be adapted for use in a wide variety of centerfire firearms. It is particularly suited to those firearms having a linearly reciprocating breech bolt. Thus, it could be applied to pump shotguns, semi-automatic/automatic shotguns, semi-automatic/automatic pistols, slide-action rifles, straight-pull rifles (such as the Blaser), semi-automatic/automatic rifles, and Mauser-type bolt rifles—among other types. Exemplary shotgun applications include the Remington 870 pump shotgun, the Remington 1100-series semi-automatic shotguns, the Winchester SXP pump shotgun, the Browning Auto 5 semi-automatic shotgun, the Mossberg 500, and the Benelli Black Eagle-series shotguns. Because the Remington 870 is widely used in law enforcement, it is used in the attached illustrations. However, those skilled in the art will readily appreciate how the invention could be applied to many other firearm models and types.
As explained previously,
In any event the finished result preferably looks like
In
The modified breech bolt of
Strike ball 96 is mounted in the center of strike plate 94. In operation, the strike ball will be struck by the nose of the modified firing pin and the strike ball will then be propelled into the primer to detonate the cartridge. It is preferable for the strike plate and arm to pivot relative to outer section 106. First hinge relief 100 and second hinge relief 102 are provided to facilitate this motion. The hinge reliefs are simply recesses in the material that extend partly through the material. They allow the material to flex more easily.
The strike ball is preferably made of a hard metal such as steel. The surrounding strike plate, outer section, and arm are preferably made as a single integral piece. These portions may be made as a die casting of aluminum or brass. They may also be formed as an injection molded polymer.
Those skilled in the art of firearms will be familiar with the term “headspace.” Headspace generally means the distance measured from a reference datum in the firing chamber itself to the bolt face. The reference datum is the chamber feature that stops the forward motion of the cartridge, when the cartridge is pressed into the chamber. For a shotgun shell, the reference datum is the forward portion of the rim recess (against which the shotgun shell's rim comes to rest). For most centerfire rifle cartridges the reference datum is somewhere along the slope of the cartridge case neck. For belted magnum rifle cartridges the reference datum is the forward portion of the belt recess.
Proper headspace is very important to the proper and safe operation of a firearm. If the head-space is too great, the cartridge will be loose in the chamber. This phenomenon can produce a case rupture. If the headspace is too small then the bolt will not close on the cartridge. Most firearms have safety features that prevent firing if the bolt is not closed.
Mass-produced firearms have a defined headspace for each caliber. A tolerance is permitted on this headspace, but it is fairly tight. As an example, the Small Arms and Ammunition Manufacturers Institute “(SAAMI”) defines the allowable headspace for a 12 gauge shotgun chamber to be between 0.0576 and 0.0716 inches (1.463 and 1.819 mm). Therefore, a shotgun shell with a rim thickness exceeding 0.0716 inches (1.819 mm) would not permit the bolt to fully close. This is ordinarily an undesirable condition.
However, the present invention presents a cartridge that inherently requires much more headspace than a standard firearm possesses. This feature means that a standard firearm cannot properly chamber the inventive cartridge and a standard firearm cannot fire the inventive cartridge. Every cartridge possesses a “critical cartridge length” which is defined as a distance from a reference datum on the cartridge configured to coincide with the reference datum on the firing chamber (when the cartridge is chambered) to the rearward surface of the cartridge configured to lie against any part of the bolt face.
The critical cartridge length for a 12 gauge shotgun shell is the rim thickness (including a slight offset for a fillet where the rim blends into the case head). SAAMI specifies the rim thickness of a 12 gauge cartridge to lie in the range of 0.0436 to 0.0576 inches (1.107 mm to 1.463 mm).
In the preferred embodiments of the present invention, the token disc is made thick enough so that the critical cartridge length becomes much too large for the inventive cartridge to be chambered in a conventional firearm. For example, the token disc can be given a thickness of 2.35 mm. Once such a disc is applied to the base of a 12 gauge cartridge, the critical cartridge length will lie between 2.457 and 2.813 mm. The token disc thickness is preferably at least 2 mm and even more preferably at least 2.3 mm. This substantial increase in critical cartridge length makes it impossible to fire the inventive cartridge in a conventional firearm.
As explained previously, nose 25 of firing pin 24 has been shortened to the position shown. The firing pin is preferably shortened by 2.0 to 2.5 mm for a disc thickness of 2.35 mm. When the firing pin shown in
The thickness of the token disc should be selected so that the critical cartridge length is substantially greater than the maximum headspace allowable for a conventional firearm of the caliber in question. In this context, the phrase “substantially beyond” means more than 1.0 mm and preferably more than 1.5 mm.
The other components of the shotgun shown are conventional. The firearm is again a Remington Model 870. A shotgun shell—modified as shown in
The reader will thereby understand and appreciate the following: (1) An inventive shotgun shell modified with the addition of the token disc cannot be fired in a conventional firearm because the bolt of the conventional firearm cannot close on the inventive shotgun shell; and (2) A firearm modified by the addition of the bolt face relief and the shortened firing pin cannot fire a conventional shotgun shell.
It is of course preferable for the inventive cartridge to possess the same safety features as a conventional cartridge. In a conventional cartridge, the primer is recessed somewhat into the base so that the primer is unlikely to be struck if the cartridge is dropped on its base. The token disc can provide the same protection.
The diameter of the strike ball is made less than the thickness of the strike plate so that the rearward most extent of the strike ball is offset from the rear of the strike plate. This fact means that the strike plate protects the strike ball in the event the modified cartridge is dropped on its base. Overhang 110 may be created by a swaging operation when a metallic material is used for the token disc. Where a plastic material is used for the token disc the overhang can be formed as part of a molding operation. The reader should bear in mind that the overhang is an optional feature. If a straight passage is used through the token disc the press-fitting of the strike ball into place can be sufficient to retain the strike ball in a recessed position.
The reader will recall that the use of the inventive cartridge requires both the inventive (modified) cartridge and a modified firearm (including a recessed bolt face). Those skilled in the art will realize that it is possible to easily change the breech bolt in many types of firearms. In the Remington 870 pump shotgun, for example, it is possible to disassemble the firearm and swap the breech bolt in a matter of minutes. There is therefore the concern that an operator might swap the breech bolt in a modified firearm and thereby equip it to fire a conventional cartridge without the token disc.
In the embodiment of
The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. Accordingly, the scope of the invention should be determined by reference to the claims ultimately presented rather than the examples given.
Pursuant to 37 C.F.R. § 1.53(c), this non-provisional patent application claims the benefit of an earlier-filed provisional application. The provisional application was assigned Ser. No. 62/333,349. It was filed on May 9, 2016 and it listed the same inventor.
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Number | Date | Country | |
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20170322004 A1 | Nov 2017 | US |
Number | Date | Country | |
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62333349 | May 2016 | US |