HK1251291B - Bolt stop buffer device in gun - Google Patents

Description

Bolt stop buffer device in the gun

Technical Field

The present invention relates to a bolt stop buffer device for a gun, the gun comprising: a bolt member disposed on a gun body so as to be capable of advancing and retracting, the bolt member being retracted by the pressure of gas generated by firing a bullet, thereby accumulating pressure in a bolt spring, and advancing by releasing the accumulated pressure, thereby performing a bullet loading operation; and a bolt stopper for stopping the bolt member from advancing.

Background Art

Many guns that have a spring (herein referred to as the bolt spring) that accumulates pressure and acts on the bolt as the gun is operated, and whose bolt advances upon release of this pressure, are equipped with a bolt stop. Self-loading guns such as assault rifles also have this mechanism. In these guns, the bolt is loaded by advancing the bolt, and after the last round is fired, it strikes the bolt stop, signaling the end of the round. This striking and stopping action is repeated each time a round is fired.

Therefore, each time the bolt strikes, it exerts a significant impact on the bolt stop, which can easily cause metal fatigue and, in severe cases, damage the bolt stop. This problem has been repeatedly reported in genuine firearms, but it is currently unclear whether there are any measures to address it. In other words, no firearms have been found that demonstrate measures to prevent damage to the bolt stop.

A review of existing technologies has also yielded unsatisfactory results. For example, a search using the keyword "bolt stop" in the Japan Patent Office's text search system yielded only three results, one of which relates to internal combustion engines, and the other two are unrelated to the bolt stop problem addressed by the present invention. Japanese Patent Application Publication No. 2010-025501 describes an invention for a mechanical power-off stop device in an electric gun, to which the present applicant's application relates. While it also mentions a "bolt stop," it is a component modeled after a real gun and only has a reset function. Japanese Patent Publication No. 2000-508051, regarding an invention for a bolt and firing pin locking device for a firearm, states in its description with reference to FIG2 that "the bolt 14 can move slightly rearward until the stop wall 25W abuts the bolt stop surface 31f." Furthermore, the article concludes with the following statement: "The bolt 14 is pressed against the cartridge case C by a large reaction spring (not shown) connected to the bolt 14 via a cylindrical support 35." However, these descriptions indicate that the impact of the bolt applied to the bolt stopper is not considered a problem.

Furthermore, searching the US Patent and Trademark Office website for "bolt stop" as a keyword yields 10 US patent publications, two of which relate to inventions related to bolt stops for firearms. Of these, US2010/0275485A1 relates to an ambidextrous bolt stop suitable for both left-handed and right-handed users. Furthermore, US2005/0183310A1 relates to a technology that links magazine removal and installation with a bolt stop. Neither of these addresses bolt impact as a concern.

Previous technical literature

Patent Literature

Patent Document 1: Japanese Patent Application Laid-Open No. 2010-025501

Patent Document 2: Japanese Patent Application No. 2000-508051

Patent Document 3: US2010/0275485A1

Patent Document 4: US2005/0183310A1

Summary of the Invention

Technical issues to be solved by the invention

The present invention has been developed in response to the above-mentioned problems, and its object is to provide a bolt stop buffer device for a gun that, by buffering the impact of the bolt member, is extremely resistant to damage even when subjected to repeated impacts, and exhibits high durability. Furthermore, another object of the present invention is to disengage the bolt stop from the bolt member when detecting the end of a round and then replacing the magazine for reloading, while maintaining the function of detecting the end of a round and then replacing the magazine for reloading, while also absorbing the impact caused by the forward movement of the bolt member.

Means for solving technical problems

To solve the above-mentioned problems, the present invention adopts the following solution: a bolt stop buffer device for a gun, the gun comprising: a bolt member disposed on a gun body so as to be able to advance and retract, the bolt member being retracted by the pressure of gas generated by the firing of a bullet, thereby accumulating pressure in a bolt spring, and advancing by releasing the accumulated pressure, thereby performing a bullet loading operation; and a bolt stopper for stopping the advancement of the bolt member, the bolt stopper having an engagement member for engaging with the bolt member that has advanced after the last bullet has been fired, and a buffer member acting on the bolt stopper to buffer an impact force applied to the bolt stopper by the engagement.

The bolt stop and buffer device of the present invention is applicable to guns that utilize the gas generated by the combustion of ammunition during firing as a pressure source. The bolt assembly retracts due to the gas pressure, primarily to facilitate the extraction of a cartridge case from the loading chamber and the loading of a cartridge into the chamber. More specifically, the loading operation involves converting the bolt's forward movement into rotation, thereby locking the powder chamber. Furthermore, the bolt stopper holds the bolt assembly in the retracted position, notifying the user that the magazine is empty and enabling quick reloading.

The bolt stopper of the present invention has the function of stopping the bolt member advancing after the last round has been fired. Specifically, the bolt stopper includes an engaging member that engages with the bolt member advancing after the last round has been fired, and a buffering member that acts on the bolt stopper to cushion the impact force applied to the bolt stopper by this engagement. The purpose of the present invention is to establish the bolt stopper as a basic component, provided it includes the engaging member that engages with the bolt member and the buffering member that acts on the bolt stopper. Therefore, it goes without saying that other components may be added to the present invention. Furthermore, the bolt member is a component that retracts due to the pressure of the gas generated by the firing of the bullet, accumulates pressure in the bolt spring, and advances upon release of this accumulated pressure, thereby causing the bullet to be loaded. Therefore, it is a component that generates impact that needs to be cushioned.

Furthermore, a preferred configuration of the present invention is that the gun body includes a cartridge-exhaustion detection member for detecting the presence or absence of a bullet supplied to the loading section in response to gun operation, and the cartridge-exhaustion detection member detects cartridge exhaustion and includes a link mechanism for causing a bolt stopper constituting the bolt stop mechanism to project within a track when the bolt member moves forward and backward, thereby achieving engagement with the engaging member.

The bolt stop preferably includes a bolt stop mechanism between the bolt member and the buffer member that receives the impact of the advancing bolt member and transmits it to the buffer member. The buffer member includes an elastic member that elastically deforms upon transmission of the impact. In this configuration, the elastic member is positioned at the rear end of the bolt stop mechanism. However, the buffer member only needs to act on the bolt stop, so the above configuration is applicable only when a bolt stop mechanism is used.

Furthermore, the bolt stopper constituting the bolt stop mechanism preferably has an elongated hole disposed on the gun body side in the longitudinal direction of the axis, and is configured to be movable within the elongated hole and rotatable about the axis. Furthermore, it is also preferred that the engaging member, comprised of an engaging portion provided on the bolt member and an engaging portion provided on the bolt stopper, be configured to form an acute angle with respect to the advancing direction of the bolt member to ensure reliable engagement. However, if such an acute angle is not appropriate, a right angle or an obtuse angle may be employed.

Furthermore, such guns include so-called single-shot guns and guns that can switch between continuous and single-shot fire. The present invention is applicable to both types of guns. In guns that can switch between continuous and single-shot fire, firing in continuous mode rapidly reduces the number of bullets, increasing the need for magazine changes and the frequency of bolt stop activation. Therefore, the impact buffering provided by the present invention is more effectively demonstrated.

Effects of the Invention

The present invention, constructed and operating as described above, provides a bolt stop buffer device for a gun that absorbs and mitigates impacts applied to the bolt component of the bolt stop by means of a buffer member, thereby providing a bolt stop buffer device that withstands repeated impacts, is extremely resistant to damage, and exhibits high durability. Furthermore, according to the present invention, the bolt stop component is disengaged from the bolt component when a magazine is replaced for reloading after detecting the end of a round, thereby maintaining the function of detecting the end of a round and replacing the magazine for reloading, while also absorbing the impact caused by the forward movement of the bolt component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a longitudinal sectional explanatory view showing an example of an assault rifle using a bolt stop buffer device in a gun according to the present invention.

2A and 2B are enlarged views showing the main parts of the bolt stop buffer device in the gun, FIG2A is an explanatory longitudinal sectional view, and FIG2B is a sectional view taken along line IIB-IIB of FIG2A .

FIG3A and FIG2B are diagrams related to the operation of the bolt stop buffer device in the gun. FIG3A is a longitudinal sectional explanatory diagram showing the state before the last round of bullet is fired, and FIG3B is a longitudinal sectional explanatory diagram showing the state in which the bolt member is retreating after the last round of bullet is fired.

4A and 4B are views related to the operation of the bolt stop buffer device in the gun. FIG4A is a cross-sectional explanatory view showing a state where the bolt member is fully retracted, and FIG4B is a cross-sectional explanatory view showing a state where the bolt member has started to advance.

FIG5A and FIG5B are diagrams related to the operation of the bolt stop buffer device in the gun. FIG5A is a cross-sectional explanatory diagram showing a state in which the bolt stop member is in an advanced position, and FIG5B is a cross-sectional explanatory diagram showing a state in which the bolt stop member is retracted within the range of the elongated hole by the buffer spring.

Explanation of symbols

10: Launcher

11: Barrel

12: Loading Department

13: Release the export

14: Trachea

15: Bolt carrier

16: Bolt key

17: Pipeline

18: Chamber

19: Pressure part

20: Bolt

21: Movable body

22: Shell

23: Movable axis

24: Bolt spring

25: Trigger

26: Magazine loading unit

27: Bullet support plate

28: Spring support plate

29: Empty

30: Magazine

31: Bolt stop

32: Relay components

33: Ammunition exhaustion detection component

34: Axis

35: Bolt stop mechanism

36: snap-fit component

37: Buffer connecting rod

38: Installation Department

39: Buffer shaft

40: Buffer component

41: Buffer spring

DETAILED DESCRIPTION

The present invention will be described in more detail below with reference to the embodiments shown in the accompanying drawings. The bolt stop buffer device for a gun according to the present invention is applicable to any gun equipped with a bolt stopper that stops the bolt assembly. The embodiments shown in the accompanying drawings relate to an assault rifle and depict the essential components necessary to explain the details of the present invention.

The gun G shown in Figure 1 includes a launcher 10 for firing bullets as a main body, a barrel 11 at the front of the launcher 10, a movable body 21 for a recoil-operating bolt carrier 15 at the rear, and a magazine loading section 26 at the bottom of the launcher 10. The barrel 11 has a loading chamber 12 at the rear for loading cartridge cases C containing bullets (bullets) B, and a discharge port 13 at the front for releasing gases generated by the firing of the bullet from the barrel interior. The bullet, when referred to as "loading a bullet," refers to the so-called live ammunition that is integrated with the cartridge case C before firing.

One end of a gas tube 14, located outside the barrel, is connected to the discharge port 13. The other end of the gas tube 14 extends rearward into the gun body and is detachably connected to and retracted from the front end of a bolt key 16. The bolt key 16 is capable of moving forward and backward integrally with the bolt carrier 15. As described above, the bolt carrier 15 is configured to move forward and backward on the gun body side. The gas pressure generated by the firing of a bullet retracts, accumulating pressure in the bolt spring 24. The released pressure causes the carrier to advance, thereby performing operations such as loading a bullet.

The bolt carrier 15 has a generally rod-like shape that is elongated from front to back. The bolt 20 is mounted in a retractable manner at the central axis of this rod-like structure. The bolt key 16 communicates with a cylinder-like chamber 18, which allows the bolt 20 to move forward and backward, via a conduit 17. Gas generated by the firing of a bullet is directed behind a piston-like pressure-receiving portion 19 of the bolt 20, which slides within the chamber 18. Furthermore, a firing pin 20a (see Figures 2A and 2B ) that strikes the detonator of the cartridge case C is retractably mounted in the central axis of the bolt 20. In this embodiment, the bolt carrier 15 to which the bolt 20 is assembled is referred to as a bolt assembly. While various bolt structures exist beyond those shown, the present invention is applicable to any gun model as long as the bolt is retracted by the pressure of the gas generated by the firing of a bullet, thereby accumulating pressure in the bolt spring and advancing by releasing the accumulated pressure, thereby performing actions such as loading a bullet.

Behind the bolt carrier 15, a movable body 21 is located. The movable body 21 comprises a housing 22 attached to the gun body and a movable shaft 23 disposed therein. The movable shaft 23 is arranged within the housing 22 so as to be movable forward and backward, and is connected to the rear end of the bolt carrier 15 at its shaft head 23a. Reference numeral 24 in the figure denotes a bolt spring. The bolt spring 24 acts to press the movable shaft 23 in the forward direction, thereby placing the bolt carrier 15 in a firing-ready position. Furthermore, the bolt spring 24 also functions as a member that receives the bolt carrier 15 during its retraction, thereby cushioning the impact of recoil.

The trigger mechanism required for the gun of the present invention is the same as that of an assault rifle, and its operation is also standard, so only a brief description will be given below. Specifically, reference numeral 25 denotes the trigger, which, when operated, releases the locked state of the hammer (not shown), causing the aforementioned firing pin 20a to strike. This mechanism strikes the detonator of the bullet loaded in the loading chamber 12, thereby firing the bullet.

The magazine 30 is located at the bottom of the launcher unit 10. The magazine 30 is detachably mounted on a magazine loading section 26 provided at the bottom of the gun body. Live ammunition is supported by a feeder plate 27 assembled therein and is pushed upward by a feeder plate spring 28 to an empty space 29 behind the loading chamber as shown in Figures 4A and 4B (see Figures 4A and 4B ).

FIG2A and FIG2B illustrate in detail a bolt stop and buffer device for a gun according to the present invention as an embodiment. The bolt stop and buffer device of this embodiment comprises a bolt carrier 15, which accumulates pressure as the gun is operated and advances due to the release of a bolt spring 24; and a bolt stopper 31, which stops the advancing bolt carrier 15. Specifically, the bolt stop and buffer device of this embodiment is configured such that, upon operation of an exhaustion detection member 33, the bolt stopper 31 projects within the trajectory X along which the bolt carrier 15 advances and retracts. Furthermore, a buffer member 40 is used to absorb the impact generated when the advancing bolt carrier 15 collides with the bolt stopper 31.

The feeder 27 also serves to detect whether a bullet B has been fired. Specifically, as the feeder spring 28, compressed by the bullet (live rounds) loaded into the magazine 30, expands due to its repulsive force, the feeder 27 rises and stops below the bolt carrier 15. Subsequently, when a bullet B is fired and the bolt carrier 15 retracts, the feeder 27 rises. The feeder 27 engages the relay 32 of the bolt stopper 31 at its rear end 27a. Thus, the feeder 27 and the relay 32 form a cartridge exhaustion detection mechanism 33.

The rear end 27a of the feeder 27 engages with one end 32a of the relay member 32 between the bolt stopper 31, thereby pushing the bolt stopper 31 upward and causing the bolt stopper 31 to protrude within the track X along which the bolt carrier 15 moves forward and backward. The feeder 27 and the relay member 32 constitute a link mechanism for connecting the ammunition exhaustion detection member 33 and the bolt stopper 31.

The relay member 32 engages with the bolt stopper 31, which constitutes the bolt stop mechanism 35. Specifically, the other end 32b of the relay member 32 engages with the bolt stopper 31 at the groove-shaped engagement portion 31a. Therefore, when the ammunition exhaustion detection member 33 detects the end of ammunition, the ammunition exhaustion information indicating that the bullets B to be loaded into the loading chamber 12 have been fired is sequentially transmitted to the bolt stopper 31 via the ammunition exhaustion detection member 33.

As can be seen from FIG2B , the relay member 32 is shown as a member extending across the left and right sides of the gun body. It is pivotally supported by the gun body via a shaft 32c on the left side of the gun body. It is configured so that its right side portion (crank-shaped in FIG2A and FIG2B ) can be moved vertically by rotating about the shaft. Furthermore, the relay member 32 has an operating portion 32d (shown on the left side of the gun body) located above the shaft 32c. A spring 32e is provided at the bottom of the relay member 32 to return the relay member 32 to a predetermined position and depress the bolt stopper 31, described later.

The bolt stopper 31 has a long hole 31b extending in the front-rear direction and is pivotally supported on the gun body side by a shaft 34 for swinging. Thus, the bolt stopper 31 can move a distance corresponding to the stroke within the long hole 31b and can rotate about the shaft 34. With this structure, the engaging portion 31c of the bolt stopper 31 is raised by the link mechanism via the relay member 32, allowing it to protrude within the track X along which the bolt carrier 15 moves forward and backward.

The bolt carrier 15 is provided with an engaging portion 15a as one of the engaging members 36. This engaging portion 15a is capable of engaging with an engaging portion 31c, another engaging member 36, provided on the bolt stopper 31 (see Figures 4A and 4B). In particular, in this embodiment, the engaging portion 15a and the engaging portion 31c are inclined at an acute angle relative to the advancing direction of the bolt carrier 15. This inclination of the engaging portion 15a and the engaging portion 31c eliminates the instability of the engagement that can occur when the engaging portion 15a and the engaging portion 31c are pivotally supported by the shaft 34 in the longitudinally elongated hole 31b of the bolt stopper 31. Forming the engaging member 36 at an acute angle relative to the advancing direction is merely one method employed in this embodiment. Depending on the conditions when the bolt carrier 15 and the bolt stopper 31 are engaged, such as the mass, speed, and material of the parts involved in the engagement, it is conceivable that a right angle or an obtuse angle may be used.

The buffer member 40 acts on the bolt stopper 31. The buffer member 40 in this embodiment includes a buffer link 37, a buffer shaft 39 mounted to a mounting portion 38 on the gun body for forward and backward movement, and a buffer spring 41 that biases the buffer shaft 39 forward. The buffer link 37 is pivotally supported on the gun body via a shaft 37b for swingability. One end of the buffer link 37 engages with the front engagement portion 31d of the bolt stopper 31, and the other end engages with the distal end of the buffer shaft 39. Thus, when the bolt carrier 15 advances and causes a collision, the impact of the bolt stopper 31 moving toward the muzzle is transmitted to and absorbed by the buffer member 40.

Furthermore, the relay member 32 and the bolt stop 31 are aligned from the muzzle toward the buttstock. Therefore, when the bolt carrier 15 advances, it strikes the bolt stop 31 of the bolt stop mechanism 35. However, the relay member 32 is designed not to contact the carrier 15, nor does it contact the bolt stop 31 even when it has moved to its maximum distance. Therefore, there is no direct contact with the relay member 32. Because the bolt stop 31 engages the shaft 34 in the elongated hole 31b, it can move to the maximum length of the elongated hole 31b. At maximum movement, the other end 32b of the relay member 32 enters the groove 31a of the bolt stop 31.

FIG3A shows the bolt stop buffer mechanism in the gun of the present invention, constructed as described above, with the last round (live round) positioned before the last round is ejected from the loading section 12. When the trigger 25 is operated to fire a bullet B, the barrel is filled with gas generated by the bullet firing. This gas pressure flows through the gas pipe 14 into the chamber 18 of the bolt carrier 15, causing the bolt carrier 15 to retract, accumulating pressure in the bolt spring 24 and performing a so-called extraction operation, ejecting the cartridge case C ( FIG3B ) from the loading chamber 12.

When the magazine 30 is empty of live ammunition, the bolt carrier 15 retracts to its maximum retracted position ( FIG. 4A ). The rebound force of the feeder spring 28 pushes the feeder 27 upward within the magazine 30 to a position 29 near the rear of the loading section 12, where it reaches its highest position. As the feeder 27 rises, an upward force acts on the relay member 32, which engages with the rear end 27a of the feeder 27 at one end 32a.

The other end 32b of the relay member 32 engages with the bolt stopper 31 in the groove 31a, transmitting the upward movement of the feed plate 27. This causes the bolt stopper 31 to rotate about the axis 34, rotating counterclockwise in FIG4A. As a result, the engagement portion 31c located above the bolt stopper 31 protrudes within the track X.

After the bolt carrier 15 has retreated to its maximum retracted position, it is then advanced by releasing the force stored in the bolt spring 24. Thereafter, the engaging portion 15a, one engaging member 36 of the bolt carrier 15, engages with the engaging portion 31c, another engaging member 36, of the bolt stopper 31 ( FIG. 4B ).

As the bolt carrier 15 moves further forward, the bolt stopper 31 is also moved forward by the engagement member 36, causing the shaft 34 to relatively shift from the front end of the elongated hole 31b to the rear end ( FIG5A ). During this movement, the bolt stopper 31 presses against the buffer link 37 engaged by the front engagement portion 31d with one end, while the other end presses against the top end of the engaged buffer shaft 39, resisting the elastic force of the buffer spring 41. Thus, the impact of the bolt stopper 31 moving toward the muzzle when the bolt carrier 15 advances is absorbed by the buffer member 40, causing the bolt carrier 15 to slowly stop.

Next, the elastic force of the buffer spring 41 pushes the bolt stopper 31 back to the rear, and the bolt carrier 15 also retreats to the position shown in FIG4B , completing the operation of the buffer mechanism ( FIG5B ). Furthermore, the magazine detacher is operated to replace the magazine, and the bolt carrier 15 is retracted by pressing the operating portion 32d of the relay member 32 or by using the charging handle (not shown). This lowers the front portion of the bolt stopper 31, disengaging the engaging member 36. As a result, the cartridge (live round) is reloaded, and the powder chamber is locked.

The bolt stop buffer device in the gun of the present invention indirectly buffers the bolt stopper 31 that stops the bolt carrier 15 via a buffer member 40, preventing damage to the bolt stopper 31 and thus protecting the gun from sudden operational failures. Furthermore, the device of the present invention also maintains the function of detecting the exhaustion of a fired bullet B and allowing for magazine replacement and reloading.

The bolt stop buffer device according to the present invention operates as described above. In conventional assault rifles and other firearms, reloading of ammunition is also performed by changing magazines, and the bolt carrier 15 is operated by operating a charging handle (not shown) to load ammunition and lock the powder chamber. This is similar to the gun to which the device according to the present invention is applied. Therefore, the device according to the present invention can be incorporated into existing guns to buffer the impact of the bolt during operation.

Claims (4)

1. A bolt stop buffer device for a gun, characterized in that, The gun includes: a bolt assembly, which is mounted on the gun body in a forward and backward manner and retracts under the pressure of gas generated by the firing of a bullet, thus storing a bolt spring; and forward by releasing the stored pressure, thereby performing the action of loading a bullet; and a bolt stop, which stops the bolt assembly from advancing. The bolt stop has a locking mechanism that engages with the bolt assembly that has advanced after the last bullet has been fired. Furthermore, it includes a buffer member that acts on the bolt stop to cushion the impact force applied to the bolt stop due to the aforementioned engagement. The gun body has a bullet depletion detection component to detect whether any bullets have been supplied to the loading section during gun operation. The aforementioned ammunition depletion detection component detects ammunition depletion and has a linkage mechanism that allows the bolt stop to protrude within the track of the bolt assembly during forward and backward movement, thereby achieving engagement via the engaging component. 2. The bolt stop buffer device in the gun according to claim 1, characterized in that, The bolt stop has a bolt-stopping mechanism between the bolt component and the buffer component that receives the impact of the advancing bolt component and transmits it to the buffer component. The buffer component has an elastic member that can elastically deform through the transmission of the impact. 3. The bolt stop buffer device in the gun according to claim 1, characterized in that, In the bolt stop mechanism, the bolt stop has an elongated hole in the front-rear direction of an axis disposed on the side of the gun body, and is configured to be able to move within the range of the elongated hole and to rotate about the axis. 4. The bolt stop buffer device in the gun according to claim 1, characterized in that, The engaging member consists of an engaging part provided on the bolt assembly and an engaging target part provided on the bolt stop, and is configured to form an acute angle with respect to the forward direction of the bolt assembly.