Projectile with closure ring, method for manufacturing closure ring and method for providing closure ring - Patents.com
The closure ring with segmented segments and an annular gasket effectively seals propellant gases during firing and allows air passage during loading, enhancing ejection accuracy and reducing projectile deformation.
Patent Information
- Application Number
- JP2025526460
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-11-11
- Filing Date
- 2023-10-12
- Publication Date
- 2025-12-16
AI Technical Summary
Existing closure ring designs for projectiles fail to effectively seal propellant gases during firing while allowing ambient air to pass during loading, leading to variations in ejection velocity (V0) and potential damage to the projectile due to friction and deformation.
A closure ring with segmented closure segments and an annular gasket, such as an O-ring or metal tension spring, is designed to expand and seal against the barrel during firing, while allowing air to escape during loading, using a groove and locking elements to secure the gasket in place.
The solution provides a robust seal that maintains ejection accuracy by minimizing variations in ejection velocity and protects the gasket, while maintaining a small profile that minimally affects projectile aerodynamics and strength.
Smart Images
Figure 2025540614000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a projectile having an obturator attached thereto, intended to be fired from a weapon system. Additionally, the present invention relates to a process for manufacturing the obturator and a process for placing the obturator on the projectile. [Background technology]
[0002] Closures, also known as belts, are used on projectiles fired from a gun barrel to provide both a gas seal between the projectile and the barrel and an efficient frictional coupling to the barrel when projectile rotation is desired. The term belt is frequently used in reference to projectiles fired from rifled barrels. Traditionally, projectiles are rotationally stabilized to achieve better aerodynamics due to the projectile's rotation during firing as a result of the rifling in the barrel. When a belted projectile is ejected from the barrel, the belt is partially deformed by the rifling, causing the belt to grip the rifling and rotate the projectile in a manner that corresponds to the pitch of the rifling. When a steerable projectile is desired, it is recommended that the projectile be roll-stabilized, i.e., non-rotating, when the fins are deployed and used. Because it is desirable to use the same barrel, and therefore the same launch device, for all projectiles, steerable projectile designs include a sliding belt, which allows them to be fired from a fluted barrel. The sliding belt of a steerable projectile engages the rifling in the barrel, creating a gas seal. As the projectile is forced into the barrel, the belt rotates in tandem with the pitch of the rifling. The connection between the belt and the projectile is such that there is low friction and it slips or slides relative to the projectile, meaning that the projectile does not rotate or rotates at a significantly lower rate than if a fixed-mount belt were used. As the projectile exits the barrel, the projectile's rotation rate decreases. In addition to the roll-stabilizing benefits of a steerable projectile, the low rotation rate in the barrel is important for reducing the forces resulting from angular accelerations that electronics and machinery attached to the projectile are subjected to during ejection.
[0003] The term closure is often used for projectiles fired from muzzle-loading grenade launchers because the purpose of the closure ring is to seal against the barrel when the projectile is fired, but at the same time allow the projectile to be loaded into the barrel in a way that prevents the closure ring from locating or creating friction against the barrel and allows any air present in the barrel to escape. The closure ring is not deformed by the barrel but expands during ejection to create a seal between the projectile and the barrel and allow the projectile to be pushed out of the barrel by the gunpowder gases.
[0004] U.S. Patent No. 6,419,235 discloses an invention showing a split closure ring made up of two parts that is provided to allow the propellant gas to expand during firing, and that is completely separated from the projectile after it leaves the barrel. The patent does not show the closure ring being provided with any kind of retention device, such as an O-ring.
[0005] WO 2007 / 106009 discloses a belt provided with an O-ring that acts as a seal and an integral element, the document does not examine any split closure rings.
[0006] The above-mentioned prior art does not solve the problem of designing a closure ring that effectively seals out propellant gases during firing, where ambient air is allowed to pass through the projectile during loading, contributing to a low variance of V0, but the resilient element is well protected within the closure ring, the closure ring has a small profile, and is located in a shallow closure groove on the projectile, resulting in a more robust projectile due to a relatively small amount of projectile material being processed to form the closure groove.
[0007] Additional problems that the present invention attempts to solve will become apparent in conjunction with the detailed description of various embodiments that follows. Summary of the Invention [Problem to be solved by the invention]
[0008] The aforementioned problem may be solved in that the closure ring is designed as a closure segment with a slot in which a protective annular gasket is arranged, which allows the closure segment to expand.
[0009] The present invention comprises a projectile designed to be fired from a barreled weapon system having attached thereto a closure ring, the closure ring incorporating at least one closure segment having at least one slot disposed therein, the closure segments being held together and held in the projectile by attaching an annular gasket to the at least one closure segment. According to a further view of the projectile in which the closure ring is arranged, the following applies in accordance with the invention:
[0010] The closure segment is provided with a groove to accommodate the annular gasket, and at least two locking elements are arranged to hold the annular gasket in the groove.
[0011] The groove is located on the rear short side of the closure segment where the annular gasket is located.
[0012] The slots on the closing segment overlap due to the conical design of the contact geometry of the slots where the first contact geometry meets the second contact geometry.
[0013] The closed ring is composed of two closed segments.
[0014] The annular gasket is an O-ring made of a polymer.
[0015] The annular gasket is an annular tension spring made of metal.
[0016] The present invention further comprises a method for manufacturing a closure ring comprising at least one closure segment including at least one slot, the method comprising: The closing segments are arranged in a ring shape, The annular gasket is disposed in a groove disposed in the closure segments, the closure segments separately or integrally forming a closure ring; The locking element is hot formed onto the closure segment to retain the annular gasket on the closure segment.
[0017] According to a further aspect of the method for manufacturing a closure ring according to the invention, the following applies.
[0018] The closure segments are placed in a hot forming station to form the locking element.
[0019] The present invention further comprises a method of disposing a closure ring comprising a number of closure segments providing an annular gasket on a projectile, the method comprising: A closure ring is placed on the fixture; A closure ring fixture is placed on the projectile; The closure ring is removed from the fixture in the groove located on the projectile; It is characterized by: [Effects of the Invention]
[0020] Existing closure or closure ring design solutions do not combine an outward recoil function with a retaining element in the form of an annular gasket that allows for easy attachment of the closure ring to the projectile. The annular gasket ensures that the closure ring remains attached to the projectile during storage and transport, and also provides a suitable elastic effect when the closure ring expands against the barrel during firing.
[0021] The powder gases cause the closure ring to expand, which effectively seals the powder gases and expands upon firing. Furthermore, the closure ring, which remains unexpanded around the projectile during loading, allows ambient air to pass by the projectile during loading. The controlled and repeatable function of the closure ring results in low dispersion of V0—i.e., small variations in ejection velocity—which directly increases ejection accuracy. Furthermore, the elastic element, which is the closure gasket, is well protected by the closure ring. The small profile of the closure ring allows for a relatively shallow closure groove to be placed on the projectile. At the same time, the small profile of the closure ring results in a small impact on the aerodynamics of the projectile after ejection, and the small profile of the belt groove results in a small impact on the projectile's strength.
[0022] After ejection, whether the closure ring is cut off or remains on the projectile depends on the choice of annular gasket and other design considerations. [Brief explanation of the drawings]
[0023] The present invention will now be described with reference to the following figures, included therein: [Figure 1] 1 shows a closure according to an embodiment of the present invention. [Figure 2] 1 shows details of a closure segment and a closure body according to an embodiment of the present invention. [Figure 3] 1 shows details of a closure segment and a closure body according to an embodiment of the present invention. [Figure 4] 1 shows details of a closure segment and a closure body according to an embodiment of the present invention. [Figure 5] 1 shows a projectile fitted with a closure according to an embodiment of the present invention. [Figure 6] 1 illustrates a portion of a closure segment according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0024] FIG. 1 shows a closure ring 1 in an embodiment having two closure segments, a first closure segment 2 and a second closure segment 3. The material for both the first closure segment 2 and the second closure segment 3 is preferably a dimensionally stable polymer, such as POM or PEEK. To avoid abrasion of the barrel during firing, it is recommended that the selected material not be excessively hard; therefore, various forms of polymers are suitable for closure segments 2 and 3. Furthermore, the closure ring seals against the barrel, ensuring that gases produced by the propellant during firing do not leak into the projectile's surroundings. Most gas pressure must be generated and maintained at the rear of the projectile. Therefore, the material selected for the closure ring must be able to seal against the gases produced by the propellant and handle the resulting pressure and temperature increases. This seal is achieved in part by the selection of the closure ring material and primarily by the design, which allows the closure ring to expand and seal against the barrel upon firing.
[0025] In a first embodiment, the closed ring 1 consists of closed segments arranged as a ring, with slots 20 arranged on the rings, which allow the rings to expand. The presence of the slots 20 means that the closed ring 1 is not a continuous ring, but is divided into annular segments, and corresponding short sides of the segments coincide with each other in the contact shape, since a first contact shape 22 on the closed segment coincides with a second contact shape 23 on the closed segment.
[0026] In an alternative embodiment, the closure ring is manufactured from two closure rings 2, 3, which are arranged to form a ring integrally with one another. Thus, the closure ring 1, which is provided with two segments 2, 3, has two slots, i.e., a first slot and a second slot. Preferably, the corresponding closure segments are of the same size. Preferably, the corresponding segments are arranged so that, when the segments are arranged together, a certain overlap is formed between them, e.g., each segment has a conical design, so that each segment forms a conical contact shape on the slot 20. In particular, if the closure ring 1 is composed of a first closure segment 2 and a second closure segment 3, the first closure segment 2 for the first slot has a first contact shape 22. This first contact shape 22 corresponds to a second contact shape 23 of the second closure segment 3. The corresponding contact shape is the result of the second slot 25.
[0027] FIG. 2 shows details of the closure segments of a closure ring. In the figure, only the first closure segment 2 is shown; however, if the closure ring is composed of two or more closure segments, the second closure segment 3 or other additional closure segments are designed similarly to the first closure segment 2. The figure also shows how annular gaskets 10 are arranged in all closure segments included in the closure ring and how they connect all closure segments into a single unit when more than one closure segment is used for a closure ring. In the first embodiment, the closure ring 1 is provided with closure segments. In the second embodiment, the closure ring is provided with two closure segments, i.e., the first closure segment 2 and the second closure segment 3, but the closure ring may be provided with a different number of closure segments, such as three, four, five, six, or more closure segments. The annular gasket may be an O-ring made of nitrile or other conventional materials for producing O-rings that provide a suitable combination of strength and flexibility and the ability to be stored or otherwise maintain excellent physical performance over time. The annular gasket may also be a tension spring made of, for example, steel or a polymer. The annular gasket 10 is placed in a groove 5, which is provided in the corresponding closure segment and adapted to receive an annular gasket of suitable dimensions. When the annular gasket is placed in the groove 5, the locking elements 7 may be deformed to hold the annular gasket 10 in the groove 5 and thereby integrally hold all the included closure segments. In a second embodiment, the first closure segment 2 and the second closure segment 3 are integrated into a closure ring consisting of the sub-components first segment 2, second closure segment 3 and annular gasket 10. Each closure segment is fitted with a number of locking elements 7, which may be deformed, to hold the annular gasket. However, preferably, each closure segment is provided with at least one locking element 7, and preferably at least three locking elements 7 are provided for the entire closure ring to hold the annular gasket.The closure ring has an upper side 16 and a lower side 17, the lower side resting against the outer surface of the projectile when the closure ring is attached to the projectile, and the upper side sealing against the barrel within the firing device when the projectile is fired from the barrel. The closure ring has a front short side 15 and a rear short side 14 along which an annular gasket is attached to the closure ring.
[0028] 3 shows how the locking element 7 is formed to hold the annular gasket 10 in the groove 5. Preferably, the forming is performed in such a way that the annular gasket is not compressed by the locking element 7 and is still operably placed in the groove 5, while the locking element 7 prevents the annular gasket 10 from leaving the groove 5. The locking element 7 is preferably formed by hot forming or melt forming so that it can be deformed without affecting the material properties of the closure segment.
[0029] FIG. 4 shows one segment of the closure ring 1, in which it is clearly visible how the annular gasket 10 is positioned in the groove 5 when the two locking elements 7, 7' as shown in the figure hold the annular gasket 10 in the groove 5.
[0030] In the illustrated embodiment, the locking elements are spaced at 30 degree intervals, which means that although only one segment of the closure ring 1 is shown and visible in Figure 4, in reality there are a total of 12 locking elements on the complete ring.
[0031] Figure 5 shows a projectile 100 equipped with a closure ring 1. The closure ring is installed at position 1, i.e., a forward position of the closure ring 30% to 95% of the total length of the projectile from the tip of the projectile. The closure ring has a width t of 10 mm to 50 mm. The closure ring is installed in a groove in the projectile with a depth of 1 mm to 10 mm. The thickness of the closure ring ranges from 2 mm to 11 mm.
[0032] Preferably, the locking elements 7, 7' are made by hot forming of articles in the closure segments 2, 3 provided by the closure ring 1. Figure 6 shows an alternative embodiment of how the protruding portion of the locking element 7 is provided on the closure segment 2 by providing two grooves 12, 12' on the closure segment 2. The grooves may be machined or otherwise made in the closure segments so that the locking element 7 can be molded to retain the annular gasket 10 in the groove 5. (Feature Description)
[0033] Grenade launcher projectiles include a propellant charge that initially causes the projectile to exit the barrel. Grenade launcher projectiles may be configured with progressively increasing amounts of propellant to adjust the range of the projectile. In this case, the propellant charge may be arranged on the projectile, often in the form of a horseshoe or ring charge.
[0034] When a projectile is placed in the barrel, for example, when the projectile is placed in the muzzle of a grenade launcher, the projectile is positioned for launch from the grenade launcher by being moved or placed into the bottom of the grenade launcher barrel. Depending on the configuration of the grenade launcher, the projectile's propellant may be ignited directly when the projectile hits the bottom of the barrel. Alternatively, the grenade launcher may have an ignition pin positioned such that the projectile's propellant is ignited when the ignition pin is activated.
[0035] When the propellant burns, gases are generated that push the projectile through the barrel, depending on the gas pressure. The gas pressure generated by ignition of the propellant behind the projectile 100 depends in part on the chemical and physical design of the propellant, but also on the weight of the projectile 100 and the friction created between the projectile 100 and the barrel. It is important that the projectile be sealed against the barrel upon ignition to prevent gas pressure from escaping through the projectile, but the seal need not be so strong that friction occurs between the barrel and the projectile upon ignition. Furthermore, since the projectile must be positioned in the barrel in a safe and functional manner, the projectile must be able to move easily through the barrel when loaded so that any filler gas, such as air, between the projectile and the barrel can escape into the gap between the projectile and the barrel. Preferably, the projectile is positioned such that a seal closure ring is not in physical contact with the barrel when the projectile is loaded, or that it has small or limited contact with the barrel, while the seal closure ring simultaneously expands to provide a seal between the projectile and the barrel during ignition and ejection of the propellant.
[0036] (Example of embodiment) An example of a projectile with a closure ring is a 60mm to 120mm grenade launcher designed to be muzzle-loaded with a smoothbore barrel.
[0037] ALTERNATIVE EMBODIMENTS The embodiments of the invention are not limited to those specifically shown, but may be varied in different ways within the framework of the claims.
[0038] For example, it is understood that the number, size, material and shape of components and details included in the closure ring may be adapted to suit the weapon system and other design features currently available.
[0039] It will be appreciated that the above projectile designs having closure rings may include several different sizes and projectile types depending on the location of use and barrel width, but the above refers to at least the most common grenade types currently available, which have diameters or calibers of at least about 25 mm and up to 200 mm.
Claims
1. A projectile (100) intended to be fired from a barreled weapon system, the projectile (100) having a closure ring (1) disposed thereon and having attached thereto at least one closure segment (2, 3) having at least one slot (20) disposed therein, the at least one closure segment (2, 3) being held together and held within the projectile by an annular gasket (10) disposed on the at least one closure segment (2, 3).
2. 2. A projectile (100) according to claim 1, characterized in that at least one closure segment (2, 3) is provided with a groove (5) adapted to accommodate the annular gasket (10), and at least two locking elements (7, 7') are arranged to hold the annular gasket (10) in the groove (5).
3. 3. A projectile (100) according to claim 2, characterized in that the groove (5) is arranged on the rear short side (14) of at least one closing segment (2, 3) on which the annular gasket (10) is arranged.
4. 4. A projectile (100) according to any one of claims 1 to 3, characterized in that the slots on at least one closing segment (2, 3) are partially overlapped by a conically shaped contact shape on at least one slot (20) where the first contact shape (22) coincides with the second contact shape (23).
5. A projectile (100) according to any one of claims 1 to 4, characterized in that the closure ring (1) consists of two closure segments (2, 3).
6. A projectile (100) according to any one of claims 1 to 5, characterized in that the annular gasket (10) is an O-ring made of a polymer.
7. 6. A projectile (100) according to any one of claims 1 to 5, characterized in that the annular gasket (10) is a tension spring made of metal.
8. A method for manufacturing a closure ring (1) having at least one closure segment (2, 3) and at least one slot (20) disposed therein, comprising: At least one closing segment (2, 3) is arranged in a ring shape, An annular gasket (10) is disposed in a groove (5) disposed in at least one closure segment (2, 3), the at least one closure segment (2, 3) separately or together forming a closure ring (1); a locking element (7) being hot-formed onto the at least one closure segment (2, 3) to hold the annular gasket (10) thereon; A method characterized by:
9. 9. A method for manufacturing a closure ring (1) having at least one closure segment (2, 3) in which at least one slot (20) is arranged, as claimed in claim 8, characterized in that the at least one closure segment (2, 3) is placed on a hot forming station to form a locking element (7).
10. A method for placing a closure ring (1) comprising a number of closure segments (2, 3) for placing an annular gasket (10) on a projectile, comprising the steps of: The closure ring is placed on a fixture; The fastener of the closure ring is disposed on a projectile; the closure ring is removed from the fixture in a groove disposed on the projectile; A method characterized by: