This invention generally relates to fluid flow baffles and more particularly to a baffle for use in a firearm sound suppressor.
It is known that firearm sound suppressors or “silencers” reduce or modify the amount of recoil or kickback and the sound level of a muzzle blast (caused by the discharge of pressurized burning gases from the firearm). Conventional firearm sound suppressors include a generally tubular housing with a series of baffles inside the housing to redirect and delay the release of the pressurized gases. These baffles can have various shapes and profiles to more effectively disperse the burning gases and lower the sound level of a muzzle blast.
One typical conventional baffle is referred to as a “K-baffle,” an example of which is shown in
One problem that has been known to occur with the use of K-baffles 400 is the potential for the rear plate portion 402 to fail and be buckled forward either by a single powerful blast or over time by the repeated impact of high-pressure burning gases against the rear plate portion 402. If the rear plate portion 402 bends toward the forward bell portion 404, the effectiveness of the sound suppressor is severely compromised, to say the least. Furthermore, a buckling of the rear plate portion 402 may also affect the central aperture 406 in such a way that a projectile may not safely be fired through the sound suppressor.
Therefore, it would be desirable to improve the baffles used in a firearm sound suppressor and address some of the problems with conventional baffles.
According to one embodiment of the present invention, a baffle configured for use in a firearm sound suppressor is disposed along a longitudinal axis that defines a path of travel for a projectile moving from a rearward side to a forward side. The baffle includes a rear bell portion having a first annular exterior surface. The rear bell portion decreases in cross-section along the longitudinal axis toward the forward side. The baffle also includes a forward bell portion including a second annular exterior surface. The forward bell portion increases in cross-section along the longitudinal axis toward the forward side. The baffle further includes a waist portion defined between and connecting the rear bell portion and the forward bell portion. A central bore extends along the longitudinal axis at least substantially through the rear bell portion. The central bore defines an annular interior surface which is sized to receive a projectile traveling along the longitudinal axis.
In some embodiments, the baffle further includes a flow aperture disposed through the waist portion to enable fluid communication between the central bore and an exterior chamber. The exterior chamber is at least partially defined by the first and second annular exterior surfaces. The forward bell portion includes a forward end and is hollowed to define a forward bell interior surface extending from the forward end to the waist portion. The rear bell portion includes a rear end with an outer peripheral edge, and the central bore includes a rear peripheral edge. An annular first groove is cut into the rear bell portion between the outer peripheral edge of the rear bell portion and the rear peripheral edge of the central bore. Additionally, a pair of partially-annular second grooves may be cut deeper into the rear bell portion from the first groove.
A first cross-flow groove may be cut deeper into the rear bell portion from the first groove between the pair of second grooves. The first cross-flow groove is also cut through the annular interior surface of the central bore so that cross flow of fluid across the central bore toward the flow aperture is formed. The baffle also includes a second cross-flow groove in fluid communication with the flow aperture and cut into the waist portion and the rear bell portion from the forward bell interior surface so as to receive cross flow of fluid from the first cross-flow groove. The central bore may be sized for .22 caliber ammunition, .45 ACP caliber ammunition, 9×19 millimeter Parabellum ammunition, or any other size of ammunition.
In another embodiment of the present invention, a baffle stack is provided for use in a firearm sound suppressor having an outer tubular shell with an interior surface and extending along a longitudinal axis. The baffle stack includes a plurality of baffles configured to contact the interior surface of the outer tubular shell and disposed in series along the longitudinal axis. Each of the plurality of baffles includes a rear bell portion, a forward bell portion, a waist portion, a central bore, and a flow aperture, as described above. Furthermore, the axial rotational orientation of each successive baffle is identical in some embodiments. In other embodiments, each successive baffle is rotated 180 degrees in orientation from an adjacent baffle.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with a general description of the invention given below, serve to explain the principles of the invention. Like reference numerals are used to indicate like parts throughout the various figures of the drawing, wherein:
Referring to
In addition to the rear bell portion 14, the baffle 10 includes a forward bell portion 16 and a waist portion 18. The forward bell portion 16 increases in external cross-section in a forward direction along the longitudinal axis 12. The waist portion connects the rear bell portion 14 and the forward bell portion 16 at their respective smallest cross-sections such that the baffle 10 has an overall X-shaped profile as most clearly shown at
The baffle 10 also includes a central bore 26 extending along the longitudinal axis and defining an annular interior surface 28. The central bore 26 extends substantially through the rear bell portion 14. In this regard, the central bore 26 extends from a rear peripheral edge 30 at a rear end 32 of the rear bell portion 14 to a forward peripheral edge 34 proximate to the waist portion 18. The central bore 26 is sized to permit .22 caliber ammunition projectiles to pass through the baffle 10 without compressing or otherwise affecting the path of the projectile.
As shown in
A pair of partially annular second grooves 42 is cut deeper into the rear bell portion 14 from the first groove 40 toward the waist portion 18. The second grooves 42 have a smaller cross-section in the axial direction than the first groove 40 such that the second grooves 42 can extend closer to the waist portion 18 than the first groove 40. The second grooves 42 include a shallow portion 44 having generally flat inner and outer sidewalls 46, 48 and a deep portion 50 having a generally semicircular cross-section (see
The pair of second grooves 42 is spaced from each other on the top and bottom of the first groove 40. Between the pair of second grooves 42 on a bottom side of the first groove 40, a first cross-flow groove 54 is cut deeper into the rear bell portion 14 from the first groove 40. The first cross-flow groove 54 includes a generally cylindrical shallow portion 56 extending forwardly from the first groove 40 and a generally hemispherical deep portion 58 extending forwardly from the shallow portion 56. The first cross-flow groove 54 is also cut through the annular interior surface 28 of the central bore 26 such that the first cross-flow groove 54 is in fluid communication with the central bore 26. The first-cross flow groove 54 is defined between a first generally U-shaped edge 60 defined between the first cross-flow groove 54 and the first groove 40, and a second generally U-shaped edge edge 62 defined between the first cross-flow groove 54 and the annular interior surface 28 of the central bore 26. As shown most clearly in
With particular reference to FIGS. 2 and 5-7, the forward bell portion 16 of the baffle 10 includes an outer peripheral edge 64 at a forward end 66 that defines a forward side 68 of the baffle 10. The forward bell portion 16 is hollowed out to define a forward bell interior surface 70 and an annular interior surface 72 at the waist portion 14. The forward bell interior surface 70 is adjacent to the second annular exterior surface 22. The annular interior surface 72 surrounds the forward peripheral edge 34 of the central bore 26. Thus, when a .22 caliber projectile is fired through the baffle 10, the projectile passes through the central bore 26 and then passes through the hollowed forward bell portion 16.
A second cross-flow groove 74 is cut from the forward bell interior surface 70 through the waist portion 18 and into the rear bell portion 14 of the baffle 10. The second cross-flow groove 74 includes a generally cylindrical shallow portion 76 extending rearwardly from the forward bell interior surface 70 and a generally hemispherical deep portion 78 extending rearwardly from the shallow portion 76. The second cross-flow groove 74 is also cut through the annular interior surface 28 of the central bore 26 such that the second cross-flow groove 74 is in fluid communication with the central bore 26. The generally cylindrical shallow portion 76 also cuts through the first and second annular exterior surfaces 20, 22 adjacent to the waist portion 18 to define a flow aperture 80 disposed generally through the waist portion 18. The flow aperture 80 enables fluid communication between the central bore 26 and the external blast chamber 24 as most clearly shown in
In operation, the baffle 10 disperses heat and pressure in the burning gases accompanying a fired projectile in multiple ways. When pressurized gases enter the rear bell portion 14 of the baffle 10, the overall flow is divided by the central bore 26, the first groove 40, and the first cross-flow groove 54. The portion of the gases redirected into the first groove 40 is forced to move transversely within the first groove 40, into the second grooves 42, or back towards the rear end 32 of the rear bell portion 14. The sharp edges 30, 52 between the central bore 26, the first groove 40, and the second groove 42 create more turbulent flow of pressurized gases, which contributes to reducing the heat and kinetic energy in the overall flow. The portion of the flow redirected into the first cross-flow groove 54 is forced immediately in a transverse direction across the longitudinal flow of pressurized gases following the projectile through the central bore 26. This cross flow of gases disrupts the generally linear flow of gases through the central bore 26 of the baffle 10, and also provides flow directed toward the flow aperture 80 and the external blast chamber 24. Pressurized gases also expand into the hollowed-out forward bell portion 16. Consequently, the baffle 10 absorbs heat and kinetic energy of pressurized burning gases flowing from a muzzle of a firearm by allowing the gases to expand, breaking up the flow of gases, creating turbulence and cross-flows in the gases, and separating the gases into different areas or chambers defined by the baffle 10.
The first baffle 10a of the baffle stack 90 is generally referred to as a “blast baffle” because it is the first baffle to absorb pressure and heat from the burning gases expelled behind a fired projectile. In this embodiment, the first baffle 10a is formed from steel, while subsequent baffles 10b, 10c in the baffle stack 90 may be formed from aluminum. One of ordinary skill in the art will appreciate that in alternative embodiments, more of the baffles 10 in the baffle stack 90 may be formed from steel or other appropriate materials within the scope of this invention. For the .22 caliber ammunition baffles 10 of the first embodiment, each baffle 10 in the baffle stack 90 is rotated 180 degrees in orientation from the previous baffle 10, as shown in
The baffle stack 90 may be operated in a dry condition or in a wet condition with liquid inserted into the baffle stack 90 to enhance the absorption of heat and kinetic energy. Additionally, the baffle stack 90 of this embodiment may be disassembled for cleaning out debris left by the fired projectile and the burning gases. Alternatively, the baffles 10 of the baffle stack 90 may be welded together, although it is usually preferred that a suppressor intended for use with .22 caliber ammunition be disassembleable. The baffle stack 90 advantageously utilizes most of the space within the outer shell 92 for the expansion of pressurized gases while redirecting and dividing the flow of gases into the various grooves 40, 42, 54 and chambers 24 as previously described. Although the X-shaped baffles 10 may be longer along the longitudinal axis 12 than conventional K-baffles, the X-shaped baffles 10 are stronger in resisting the forces of the pressurized burning gases and more effective in reducing the noise level of muzzle blast than a comparable length of K-baffles in a baffle stack.
A second embodiment of a baffle 110 for use in a firearm sound suppressor is illustrated in
The primary difference in the second embodiment of the baffle 110 is the relative size of the central bore 126 compared to the annular first groove 140 and annular second grooves 142 in the rear bell portion 114. The central bore 126 is larger in cross-sectional width than the first and second grooves 140, 142. Additionally, a baffle stack (not shown) including a plurality of these baffles 110 may not rotate each successive baffle 180 degrees from adjacent baffles in the baffle stack. The baffle stack of this embodiment may also be welded together or into an outer tubular shell so that the baffle stack cannot be disassembled. A similar arrangement of a welded, consistent orientation baffle stack will be described with respect to the next embodiment of a baffle 210, below. In any event, the X-shaped baffles 110 are still stronger in resisting the forces of the pressurized burning gases behind a .45 ACP caliber projectile and more effective in reducing the noise level of muzzle blast than a comparable length of K-baffles in a baffle stack.
A third embodiment of a baffle 210 for use in a firearm sound suppressor is illustrated in
Unlike the first two embodiments, the baffle 210 includes a rear bell portion 214 and a forward bell portion 216 that are generally hemispherical in shape, and more specifically, truncated hemispheres. As shown most clearly in
Another difference for the baffle 210 of this embodiment is that the central bore 226 is sized for 9×19 millimeter projectiles, so the central bore 226 is again larger in cross-sectional width than the annular first groove 240 and annular second grooves 242 (see
There is more room in the rear bell portion 214 for groove cuts because of the longer length of the rear bell portion 214 compared to previous embodiments. Thus, a pair of annular third grooves 296 is cut deeper into the rear bell portion 214 towards the waist portion 218 at the pair of annular second grooves 242. The third grooves 296 are smaller than the second grooves 242 and define a groove edge 298 with the second grooves 242. In operation, the baffle 210 of the third embodiment effectively absorbs heat and kinetic energy of burning pressurized gases following a fired projectile by allowing the gases to expand, breaking up the flow of gases, creating turbulence and cross-flows in the gases, and separating the gases into different areas or chambers defined by the baffle 210.
Similar to other embodiments, the first baffle 210a or “blast baffle” may be formed from steel, while subsequent baffles 210b, 210c in the baffle stack 290 may be formed from aluminum. One of ordinary skill in the art will appreciate that in alternative embodiments, more of the baffles 210 in the baffle stack 290 may be formed from steel or other materials within the scope of this invention. In this baffle stack 290, the rotational orientation of each baffle 210 remains the same along the longitudinal axis 212. In this regard, the first cross-flow groove 254 of the first baffle 210a directs flow generally upwardly, as does the first cross-flow groove 254 of the second baffle 210b. Although the generally X-shaped baffles 210 are longer along the longitudinal axis 212 than conventional K-baffles, the X-shaped baffles 210 are stronger in resisting the forces of the pressurized burning gases and more effective in reducing the noise level of muzzle blast than a comparable length of K-baffles in a baffle stack.
While the present invention has been illustrated by the description of the embodiment thereof, and while the embodiment has been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, the generally frusto-conical shape of the rear and forward bell portions 14, 16 of the (.22 caliber) first embodiment of the baffle 10 could be formed with a generally truncated hemispherical shape, and the generally hemispherical shape of the rear and forward bell portions 214, 216 of the (9×19 millimeter Parabellum) third embodiment of the baffle 210 could be formed with a generally frusto-conical shape. Therefore, the invention in its broader aspects is not limited to the specific details representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of applicant's general inventive concept.
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