Munition with Unexploded Ordnance Limiting |
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申请号 | US14878355 | 申请日 | 2015-10-08 | 公开(公告)号 | US20160102954A1 | 公开(公告)日 | 2016-04-14 |
申请人 | Safariland, LLC; | 发明人 | John Hultman; | ||||
摘要 | A munition includes a projectile and a propellant unit. A propellant insert in the propellant unit has at least two propellant chambers each receiving a respective propellant charge. A primer mechanism is actuatable to ignite all of the propellant charges in the propellant insert. The combustion products of a selected one of the propellant charges are directed to the projectile and the combustion products of the non-selected propellant charges are vented. | ||||||
权利要求 | |||||||
说明书全文 | This application claims priority to, and the benefit of the filing date of, U.S. Provisional Application No. 62/061,985, filed Oct. 9, 2014. This application incorporates by reference all the subject matter of that provisional application. Munitions are typically designed with a specific operational range, and for a single use. The range and usage are designed to deliver the maximum effect without compromising accuracy. This is accomplished by selectively setting the amount of propellant in the shell, or by altering the containment or shell base configuration. In this manner, manufacturers can offer the same round in multiple operational distances. While this broadens the overall product usage, it also forces the end user either to carry a single munition that may be either ineffective or unsafe, or to carry a large number of shells. The present invention relates to a munition (cartridge) that includes a propellant unit carrying multiple propellant charges of different capacities, thus allowing the munition's payload to be deployed at a selected one of multiple different engagement distances. In such a case, only one propellant charge is actuated to propel the projectile. It is not desirable to leave the remaining propellant charges in the munition as unexploded ordnance (“UXO”). The present invention addresses that issue. The propellant unit 20 ( The shell 22 has, at its downstream end (to the right as viewed in The cylinder 40 has within it a plurality of propellant chambers 42. The propellant chambers 42 are disposed in a circular array centered on the axis 34. The propellant chambers 42 extend axially to the downstream end surface of the cylinder 40, and may be necked down as shown in The munition 10 when assembled includes one or more propellant charges 44. The propellant charges 44 may be preformed cartridges, of may be loaded as individual components into the propellant chambers of the cylinder. Each one of the propellant chambers 42 receives an individual propellant charge 44. The propellant unit 20 also includes a sealing ring (not shown) that acts as a gasket between the cylinder and the shell 22. The cylinder 40 has a circular upstream end surface 60 ( A circular end disk 70 is secured with several fasteners 72 to the upstream end surface 60 of the cylinder 40. The disk 70 has at it center a primer cavity 74 that receives a primer 76. The primer cavity 74 in the end disk 70 is in fluid communication with the primer passages 62 in the cylinder 40. The primer 76 is ignitable so as to ignite the propellant charges 44 in the cylinder 40, as described below in detail. The propellant unit 20 also includes an index assembly 50. The index assembly 50 ( The portion of the shell 22 that is downstream of the cylinder chamber is formed as a manifold 80. The manifold 80 includes one through passage 82 ( The manifold 80 also includes vent passages 86 ( When the cylinder 40 is rotated within the shell 22 and stops in a selected index position, the selected propellant chamber 42 is centered on the through passage 82 and is thus in a position to direct combustion products against the projectile 12. To change the munition 10 to a different propellant, the operator depresses and holds in the index pin 52, pushing axially in a direction to the left as viewed in In operation of the munition 10, the primer charge 76 is activated by a firing pin or the like. The combustion products of the primer charge 76 flow through the primer passage 62 to the three propellant chambers 42. As a result, all three propellant charges 44 are ignited simultaneously. The combustion products of the selected propellant charge 44 flow out of its propellant chamber 42 and into the through passage 82 in the manifold 80. Those combustion products engage the projectile 12, causing the projectile to be ejected from the shell 22 as desired. The combustion products of the other two (non-selected) propellant charges 44 do not flow into contact with the projectile 12. Rather, they flow through the vent passages 86 in the manifold 80 and into the vent chamber 88, from where they are vented through the barrel of the launcher. Thus, in accordance with the invention, a single ignition sequence ignites all three propellant charges 44, but the combustion products of only one of the three charges are used to propel the projectile 12. The combustion products of the other two propellant charges 44 are vented. As a result, no unexploded ordnance remains in the munition 10 after firing of the projectile 12, even though only one charge 44 is used to propel the projectile. In the propellant unit 20a, the cylinder 40a has a well 90 ( The plug 92 limits the ability of combustion products of the non-selected propellant charges 44a to intermingle with (supplement) the combustion products of the selected propellant charge 44a. This issue might arise because all the propellant chambers 42 are connected in fluid communication with each other by the primer passages 62a. This problem is minimized by closing off the primer passages 62a as soon as possible during the ignition sequence. Specifically, when the primer is ignited, the force of the combustion products of the primer overcomes the biasing force of the spring 94 and moves the plug 92 toward the projectile. This movement of the plug 92 away from the end disk 70a uncovers the primer passages 62a, and the combustion products of the primer are allowed to flow through the primer passages into the propellant chambers 42a. All the propellant charges 44a ignite and generate combustion products. After the combustion products of the primer have flowed into the propellant chambers 44a, there is no axially directed force on the plug 92 (form the primer combustion products) that would overcome the biasing force of the spring 94. The biasing force of the spring 94 urges the plug 92 back to its starting position, and in this position, the plug again blocks off the primer passages 62a. As a result, combustion products from the non-selected propellant chambers 42a cannot backflow into the selected propellant chamber. From the foregoing description, those skilled in the art will perceive improvements, changes, and modifications in the invention. Such improvements, changes, and modifications within the skill of the art are intended to be covered by the appended claims. |