Method and apparatus for propelling a pellet or BB using a shock-sensitive explosive cap |
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申请号 | US11702350 | 申请日 | 2007-02-05 | 公开(公告)号 | US08191480B2 | 公开(公告)日 | 2012-06-05 |
申请人 | Chris Mcaninch; | 发明人 | Chris Mcaninch; | ||||
摘要 | A method and apparatus for expelling a projection from an air gun by striking a primer cap filled with a shock-sensitive explosive compound, causing the cap to explode, which in turn rapidly compresses a volume of air located between the projectile and the cap, causing the projectile to exit from the barrel of the air gun at a high rate of speed. | ||||||
权利要求 | What is claimed is: |
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说明书全文 | Applicant claims the benefit of Provisional Patent Application No. 60/771,568 filed on Feb. 8, 2006. 1. Field of the Invention This invention relates to a method and apparatus of propelling a pellet or BB from a gun using a shock-sensitive explosive cap or primer. As conventional firearms come under political attacks, gun enthusiasts are being forced to look to other means of recreational shooting. More and more, these enthusiasts are turning to air actuated shooting rifles and handguns to hunt and to target practice. 2. Description of the Prior Art One of the earliest known air guns was the Austrian 1780 model named “Windbiichse” which literally translates to “wind rifle” in German. This early design was developed by Bartholomeo Girandoni. The concept of an air gun has not changed to a large degree since this early design. An air gun generally operates by having compressed air rapidly released from an air tight chamber behind a projectile that then travels rapidly through a gun barrel. The means by which this compressed air is generated is the greatest distinguishing feature amongst the many different designs of air guns. The reservoir gun, sometimes called “multi-pump” gun, has a pump to compress air into a reservoir. These pumps can be operated in a myriad of ways, but the most common is to have part of the gun stock serve as a pump lever. The lever is hinged at one end and the other end is allowed to swing away from the gun barrel. The compressed air is generated by forcing the lever into the closed position. The reservoir gun, or pump design, is still commonly used in the United States. The most common application of this technology is typically referred to as a “BB gun.” This type of gun has been made famous by U.S. manufacturers Daisy and Crossman. The greatest limitation about the “multi-pump” pneumatic gun is that it requires multiple compressions to generate enough compressed air to effective launch a projectile. Because of the typical design of the pump, there is a very real concern of pinching fingers between the pump lever and the gun barrel. Further, the pumping action requires a certain level of coordination and strength that may be troublesome to some users. Additionally, because it is a multiple pump design, it is problematic to generate consistent compressed air pressure in the chamber, and thus problematic to generate consistent projectile speed and trajectory. Another air gun design is the spring-piston gun. This design typically is a single shot design that requires the breaking of the gun barrel at a hinged point to load a single projectile. After the projectile is loaded into the barrel, the barrel is then swung shut. While closing the gun barrel, a spring is compressed behind the projectile. When the trigger is pulled, the spring is released, and the air between the projectile and the plunger attached to the spring is compressed at a high rate of speed. This compressed air then forces the projectile through the gun barrel at a high rate of speed. The problem with the spring-piston gun is that the spring is very strong or powerful. For the trigger to be effective, the spring is held back by a sear that has a very small engagement area. There is a very real danger that fingers can be pinched or even crushed if the sear was to unexpectedly release the spring. Another method of compressing gas is to use pressurized air held in separate canisters or tanks. Typically, these canisters are filled with either carbon dioxide or compressed air. The canister then serves as a reservoir when attached to the air gun. A portion of the gas is ejected each time a projectile is fired out of the air gun. The problem with this compressed gas system is that the pressure steadily decreases with each shot. CO2 canisters are also temperature sensitive, in that lower temperatures cause reduced pressure, which reduces velocity. Compressed air tanks are less sensitive to temperature variations. This variance in pressure causes the flight path of each projectile to be different. The difference in flight effectively renders the canister style systems ineffective as hunting or target shooting tools. Additionally, the canisters are bulky and heavy, making the use of the air gun awkward when the canisters are attached. Further, there is an inherent danger when handling canisters of highly compressed gas. It is very desirable to have an alternative to traditional firearms that can be used by firearm enthusiasts to recreationally target shoot and hunt that has a high degree of repeatable accuracy. Therefore, an easily assembled and accurate non-firearm rifle or hand gun utilizing a new method of propulsion is important. A general feature of the present invention is the provision of an improved method of propelling a projectile, such as a pellet or BB, along a gun barrel by use of an explosive percussion or primer cap. A further feature of the present invention is the variance of projectile velocity by adjusting the gap between the cap and projectile in the chamber. An additional feature of the present invention is the provision of a highly repeatable projectile velocity. Yet another feature of the present invention is the provision of a method of loading an air gun that does not require a spring or pump. A further feature of the present invention is the utilization of commonly available components to effectuate the method disclosed. The present invention generally comprises a method of propelling a projectile from a gun barrel by a shock-sensitive explosive mixture cap and the projectile in an enclosed chamber. The method comprises inserting a projectile, typically a pellet or BB, into a gun barrel adjacent to one end of a compression chamber and placing a primer cap at the other end, with the explosive portion of the cap towards the projectile. The chamber is then closed, creating an essentially airtight chamber. The primer cap is then struck by a hammer, causing the shock-sensitive explosive mixture to rapidly expand and then rapidly eject the projectile along the gun barrel. The speed of which the projectile exits the gun barrel is determined by the length and diameter of the gap between primer cap and the projectile in the compression chamber, if any. The highest velocity is achieved when the pellet or BB engages the primer cap. The present invention will now be described, by way of example, with reference to the accompanying drawings in which: The present invention will be described as it applies to its preferred embodiment. It is not intended that the present invention be limited to the described embodiment. It is intended that the invention cover all modifications and alternatives, which may be included within the spirit and scope of the invention. In a preferred embodiment, the method of projecting a projectile along a gun barrel is achieved through the actuation of a primer cap the rear end of the barrel to force the projectile to exit the opposite end of the gun barrel at a specified rate of speed. Referring to the drawings. As shown in The breech plug (34) is provided with a round opening (44) sized to accommodate the primer cap (12), which in the preferred embodiment, is a non-rimfire, such as a 209 type primer cap, such as that known in the art. The opening (44) provided in the breech plug (34) is preferably sized and configured so as to provide substantially airtight engagement around the primer cap (12), but not so tight as to prevent removal of the primer cap (12) from the breech plug opening (44). The primer cap (12) is provided with a rim (46) to catch on the face (48) of the breech plug (34) to prevent the primer cap (12) from being pushed through the opening (44) in the breech plug (34). The rim (46) can also be used for automatic or manual removal of the primer cap (12) from the breech plug opening (44). A pellet (50) is provided in the barrel (28). The pellet (50) may be loaded through the muzzle. Alternatively, the pellet (50) may be loaded through the breech end (42) of the barrel (28) before the insertion of the primer cap (12). If desired, the primer cap (12) may instead be coupled to the portion of the gun (26) having the firing mechanism (30) so that the pellet (50) may be loaded into the barrel (28) through the breech end (42) of the barrel (28) before the gun (26) is closed. As shown in The sabot (56) provides an airtight seal and prevents damage to the body (54) of the pellet (50). The sabot (56) is provided in contact with the primer cap (12) to achieve pellet speeds preferably in excess of 500 feet per second and, more preferably, in excess of 1,000 feet per second, and most preferably in excess of 1,250 feet per second. Alternatively, the pellet (50) may be spaced apart from the primer cap (12) to change the speed of the pellet (50). If desired, the barrel (28) may be provided with ridges to engage the sabot (56) at various distances from the primer cap (12) to create any desired airspace between the primer cap (12) and pellet (50) to change the speed of the pellet (50) existing from the barrel (28). As shown in A general description of the present invention as well as the preferred embodiment to the present invention has been set forth. Those skilled in the art to which the present invention pertains will recognize and be able to practice additional variations in the method and systems described which fall within the teaching of this invention. Accordingly, all such modifications and additions are deemed to be within the scope of the invention which can be limited only by the claims appended hereto. |