Patent Publication Number: US-11378348-B2

Title: Firearm noise suppressor

Description:
RELATED APPLICATIONS 
     This application claims priority to Provisional Patent Application No. 62/786,734, filed Dec. 31, 2018, and incorporates the same herein by reference. 
    
    
     TECHNICAL FIELD 
     This invention relates to a firearm noise and recoil suppressor, also colloquially called a silencer. Particularly, it relates to a baffle system for a user-configurable, modular suppressor which may be used with or without an add-on baffle/housing module. 
     BACKGROUND 
     It is known that firearm sound suppressors reduce or modify the amount of recoil and the sound level of the muzzle blast (caused by the rapid discharge of expanding propellant gases from the firearm). Typical suppressors include a generally tubular housing with an interior cavity divided into multiple chambers by a series of baffles inside the housing to redirect and delay the release of pressurized gases. Unlike other types of fluid stream mufflers, each baffle must include a passageway axially aligned with other baffles, end caps, and the bore axis of the firearm barrel to allow a projectile to pass through the suppressor without making contact. 
     Firearm noise suppressors reduce the sudden and loud noise of rapidly expanding propellant gases exiting the muzzle of barrel by delaying the high-pressure release of gases, consuming kinetic energy of the blast by creating internal turbulents, and by absorbing heat energy from the gas flow. Various standard baffle shapes, such as K-baffles, M-baffles, and cone baffles are well known. Likewise, monolithic suppressor cores have been made where a number of baffles and chambers are unified in a single piece of material. Modular suppressors have been made that allow the user to choose the number of baffles to be used for a given situation. A shorter suppressor with fewer baffles weighs less and adds less length to the muzzle of the firearm, while giving up some degree of sound suppression performance. Longer suppressors with more baffles provide superior sound and recoil suppression performance but add weight and length to the firearm. With a standard suppressor, the user must choose which of these alternatives better suits the situation. A modular suppressor provides the user with both options in a single device. 
     SUMMARY OF THE INVENTION 
     The present invention provides a modular firearm suppressor which can be used in a shorter, single-stage configuration or in a longer, two-stage configuration. 
     The first stage includes a blast module and a first baffle module with a brake chamber between them. The blast module can have an annular blast chamber around a ported passageway that receives the muzzle or a muzzle attachment device. The first baffle module includes a ported central passageway with a series of radial, helical chambers. The second stage cannot be used separately, but is detachably secured to the first stage, and includes a second baffle module that has a ported central passageway with a series of radial, helical chambers. 
     Other aspects, features, benefits, and advantages of the present invention will become apparent to a person of skill in the art from the detailed description of various embodiments with reference to the accompanying drawing figures, all of which comprise part of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Like reference numerals are used to indicate like parts throughout the various drawing figures, wherein: 
         FIG. 1  is a rear isometric view of a two-stage firearm suppressor according to an embodiment of the present invention; 
         FIG. 2  is a front isometric view thereof; 
         FIG. 3  is a side elevation view thereof; 
         FIG. 4  is a side sectional view taken substantially along line  4 - 4  of  FIG. 1 ; 
         FIG. 5  is an isometric, partially cut-away view thereof; 
         FIG. 6  is a side elevation view of a single-stage firearm suppressor according to an embodiment of the present invention; 
         FIG. 7  is a side sectional view thereof taken substantially along line  7 - 7  of  FIG. 8 ; 
         FIG. 8  is a rear isometric view of the separated stages of a modular firearm suppressor according to an embodiment of the present invention; 
         FIG. 9  is a front isometric view thereof; 
         FIG. 10  is a rear isometric exploded view thereof; and 
         FIG. 11  is a forward isometric exploded view thereof. 
         FIG. 12  is a first isometric view showing a thread-protector/retainer cap connected to the first stage nose cap; and 
         FIG. 13  is an opposite isometric view thereof showing the thread-protector/retainer cap and first stage nose cap separated. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the drawing figures, this section describes particular embodiments and their detailed construction and operation. Throughout the specification, reference to “one embodiment,” “an embodiment,” or “some embodiments” means that a particular described feature, structure, or characteristic may be included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” or “in some embodiments” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the described features, structures, and characteristics may be combined in any suitable manner in one or more embodiments. In view of the disclosure herein, those skilled in the art will recognize that the various embodiments can be practiced without one or more of the specific details or with other methods, components, materials, or the like. In some instances, well-known structures, materials, or operations are not shown or not described in detail to avoid obscuring aspects of the embodiments. “Forward” will indicate the direction of the muzzle and the direction in which projectiles are fired, while “rearward” will indicate the opposite direction. “Lateral” or “transverse” indicates a side-to-side direction generally perpendicular to the axis of the barrel. Although firearms may be used in any orientation, “left” and “right” will generally indicate the sides according to the user&#39;s orientation, “top” or “up” will be the upward direction when the firearm is gripped in the ordinary manner. 
     Referring first to  FIGS. 1-3 , therein is shown a modular firearm noise suppressor  10  according to one embodiment of the present invention. This suppressor  10  has two separable modules or stages: a first stage  12  that attaches to the barrel of a firearm (not shown), and a second stage  14  that is removably attached to the first stage  12 . The first stage  12  can be used independent of the second stage  14 . However, the second stage  14  cannot be used independent of the first stage  12 . Each of the stages  12 ,  14  include a substantially cylindrical housing tube  16 ,  18 . In the illustrated embodiment, the housing tube  18  for the second stage  14  has a smaller diameter than that of the housing tube  16  for the first stage  12 . 
     Referring now also to  FIGS. 4, 5, 10, and 11 , the housing tube  16  of the first stage  12  includes an annular insert  20  that provides a reduced diameter shoulder portion that provides an interior annular rim  22  and includes interior connection threads  24 . The annular rim  22  could be provided by a shoulder integral with the housing tube  16 , or the insert  20  may be permanently joined to the housing tube  16 , such as by adhesive or welding. An exterior surface at the rear of the housing tube is also threaded  25 . A collar  28  has interior threads  30  that mate with the exterior threads  25  at the rear of the housing tube  12 . The collar  28  includes a reduced diameter lip  32  defining a rear opening  34 . Optionally, the exterior surface of the collar  28  may include knurling or other grip-enhancing texture or feature, as shown. 
     As shown in  FIGS. 5 and 7 , inside the first stage housing tube  16  are a blast module  36  and a first baffle module  38 . The blast module  36  and first baffle module  38  may be coupled together, such as by threads  40 ,  42 . Both the blast module  36  and first baffle module  38  have an exterior diameter sized to closely fit within the interior of the first stage housing tube  16 . Both include an axial bore that will be aligned with the bore axis of a firearm barrel  43  to which the suppressor  10  is attached and which is sized to allow a projectile of a selected diameter to pass without contact. 
     The blast module  36  includes a rear end wall  44  and is configured for attachment to the muzzle end of a firearm barrel  43 . In the illustrated embodiment, threads  46  are provided that can directly attach to exterior threads at the muzzle of a barrel  43 . Alternatively, the suppressor  10  may be configured with lugs or acme threads to engage an adapter or muzzle device (not shown), such as a flash hider or muzzle brake. Such a muzzle device could extend into the blast module  36  and be configured to contribute to diverting the flow of expanding propellant gases radially into the blast module  36 . Extending forward from the rear end wall  44  is a tubular portion  45  having a plurality of elongated and circumferentially spaced ports  48  forward of the threaded portion  46 . Outward of this tubular portion  45 , between a forward wall  50  and the rear end wall  44  is an annular space that may be divided into chambers by a plurality of longitudinal, radial vanes  52 . In the illustrated embodiment, cutouts  54  in the vanes  52  allow cross flow of pressurized gas between the chambers defined between the vanes  52 . These collectively provide a blast chamber with forward wall  50  acting as a blast wall or baffle against which propellant gases of the highest temperature, highest velocity, and highest pressure will impact. For these reasons, and because the blast module  36  supports the suppressor  10  on the firearm barrel, the blast module  36  should be made from a durable material resistant to erosion and not degraded by high temperatures. Alternatively, the blast module vanes  52  may have radially inward edges that define the axial passageway through which a projectile passes, eliminating the tubular portion  45  and its ports  48 . 
     Extending forward from the forward wall  50  of the blast module  36  is a cylindrical wall  56  that may include internal threads  40  at its forward end. As previously described, threads  42  at its rearward end of the first baffle module  38  can be used to connect the blast module  36  and first baffle module  38 . A key  58  may be provided on the shoulder portion  20  or annular rim that engages a corresponding notch  60  on the first baffle module  38  (or vice versa). This engagement prevents the first baffle module  38  from rotating inside the first stage housing tube  16 . In turn, the threaded engagement  40 ,  42  between the first baffle module  38  and blast module  36  prevent the blast module  36  from rotating inside the tube  16 . Because the blast module  36  carries the means for connecting the suppressor  10  to the firearm barrel (such as direct threads  46 ) in this embodiment, it is important that the blast module  36  not rotate inside the housing tube  16  so that the suppressor  10  may be turned as a unit for attachment to the firearm barrel by gripping the housing tube  16 . The collar  28  keeps the blast module  36  and first baffle module  38  captured within the tubular housing  12  and against the annular rim  22 , while allowing ease of disassembly for maintenance. 
     A brake chamber  64  is defined between a rear end wall  62  of the first baffle module  38  and the forward wall  50  and cylindrical wall  56  of the blast module  36 . The brake chamber  64  allows high pressure propellant gas flowing through an aperture  66  in the forward wall  50  to expand and stabilize before venting into the next chambers of the first baffle module  38 . This pressure stabilization can be important for reducing back pressure against the operating system of a gas operated firearm action and to prevent cross-flow too close to the projectile that may affect its flight stability. A truncated tubular passageway  68  may extend rearwardly from the rear end wall  62  of the first baffle module  38  to induce turbulence into the flow of propellant gas behind the projectile and to retard the venting of gas into the next chamber. 
     The first baffle module  38  has three chamber areas defined between the rear end wall  62  and a forward end wall  70 , and separated by two intermediate walls  72 ,  74 . A tubular passageway  76  is axially aligned with the bore of the barrel  43  and allows passage of a fired projectile without contact. The tubular passageway  76  has circumferentially spaced ports  78  that vent propellant gas radially into the annular spaces between the rear end wall  60 , forward wall  70 , intermediate walls  72 ,  74 , and the housing tube  16 . The three annular spaces are divided into elongated chambers by elongated baffle vanes  80 . In the illustrated embodiment, six circumferentially spaced vanes  80  in each space define six chambers in each space. The ports  78  may be positioned toward the rear of each chamber so the forwardly flowing gas stream can freely enter. Between each set of ports  78 , the tubular passageway  76  may be uninterrupted, so as to maintain projectile flight stability. 
     According to the illustrated embodiment, the ports  78  and the vanes  80  are configured helically and in the direction of the projectile&#39;s spin (right hand twist). If desired, the vanes  80  and chambers between them could be axially oriented or could helix in the direction opposite the spin of the projectile. However, the helical configuration allows the flow path of each chamber to be longer and increases the heat-adsorbing surface area of the vanes  80 . 
     At the forward end of the first baffle module  38 , where the second stage  14  attaches to the first stage  12 , there is a second brake chamber  82 . This chamber  82  again allows the propellant gas flowing through tubular passageway  76  to expand and stabilize before venting into the second baffle module  84 . The volume of the second brake chamber  82  can be smaller than that of the first brake chamber  64 . 
     As shown in  FIGS. 4, 5, 10, and 11 , the operative structure of the second baffle module  84  is similar to that of the first baffle module  38 . However, if the diameter of the second stage housing tube  18  is smaller than that of the first stage housing tube  16  (as shown), the volume of each chamber is smaller. The pressure of the propellant gas will have been significantly reduced in the first stage  12  and, while the second stage  14  significantly further reduces the report and recoil, it can do so effectively with smaller chambers. The second baffle module  84  includes a tubular passageway  86  axially aligned with the first tubular passageway  76  and bore of the barrel  43 . Again, the second baffle module  84  has three chamber areas defined between a rear end wall  88  and a forward end wall  90 , and separated by two intermediate walls  92 ,  94 . The tubular passageway  86  has circumferentially spaced ports  96  that vent propellant gas radially into the annular spaces between the rear end wall  88 , forward wall  90 , intermediate walls  92 ,  94 , and the housing tube  18 . The three annular spaces are divided into elongated chambers by elongated baffle vanes  98 . In the illustrated embodiment, six circumferentially spaced vanes  98  in each space define six chambers in each space. The ports  96  may be positioned toward the rear of each chamber so the forwardly flowing gas stream can freely enter. Between each set of ports  96 , the tubular passageway  86  may be uninterrupted, so as to maintain projectile flight stability. 
     Again, according to the illustrated embodiment, the ports  96  and the vanes  98  are configured helically and in the direction of the projectile&#39;s spin (right hand twist). If desired, the vanes  98  and chambers between them could be axially oriented or could helix in the direction opposite the spin of the projectile. However, the helical configuration allows the flow path of each chamber to be longer and increases the heat-adsorbing surface area of the vanes  98 . 
     As previously described, the second stage  14  is attached to the first stage  12  by the threaded connection  24 ,  26 . The second baffle module  84  may be keyed to the second tubular housing  18 , for example, by an alignment pin  100  that fits into a notch  102  in the rear edge of the tube  18  to prevent relative rotation between them. The rotational orientation of the baffle module  84  is not critical to its performance, but the tube  18  provides a gripping surface by which the second stage  14  is turned to thread it onto or off of the first stage  14 . Finally, a second stage nose piece  104  is threaded onto the forward end of the second baffle module  84  to secure the tubular housing  18  in place. The nose piece  104  may be in the form of an internally threaded (at  106 ) castle nut with notches that can be engaged by a tool for rotation. In the illustrated embodiment, the notches  108  are relatively large and are transversely aligned so that a nonspecific, field-expedient tool (such as a screwdriver, multitool, knife, or bayonet) may be used. If desired, the nose piece  104  could include a transverse wall (not shown) with a central opening that would create another brake chamber forward of the second baffle module  84 . If the nose piece  104  is fixed permanently or semi-permanently to the second baffle module  84 , the notches  108  can be used to loosen the second stage  14  from the first stage  12 . 
     Other than the key notch  102 , the second tubular housing may be a simple tube with no internal or external threads. This minimizes cost of manufacture and prevents use of the part, separate from the combination, as a part of another suppressor assembly. When the nose piece  104  is threaded in place on forward threads  110  of the second baffle module  84 , the second stage  14  may be handled as a unit without any lose parts. 
     The blast module  36  and both baffle modules  38 ,  84  each may be made as a monolithic unit, such as by machining from a single piece of material, “printing” by additive manufacturing methods and materials, casting, or molding. 
     In the two-stage configuration (illustrated in  FIGS. 1-5 ), the suppressor  10  has maximum noise, flash, and recoil suppression performance, but at a premium of additional length and weight. For shots where the shooter is at a fixed location and/or can rest the rifle on a support or bipod, this configuration is ideal. When the shooter is moving or operating in close quarters, a shorter and lighter configuration—with some sacrifice to performance—may be preferred. In the latter situation, the modular suppressor  10  may be used in its single stage configuration (shown in  FIGS. 6 and 7 ). 
     Referring now in particular to  FIGS. 5, 6, and 7 , in the single stage configuration, the first stage  12  of the suppressor  10  can be used alone, providing hearing-safe sound suppression in a shorter, lighter system. When the second stage  14  is removed (by unthreading the connection  24 ,  26 , a first stage nose piece  112  is attached in its place. The first stage nose piece  112  has threads  26   a  that match those  26  of the second stage baffle module  84  and it has a forward wall  114  that defines an alternate second brake chamber  82   a  forward of the front end wall  70  of the first baffle module  38 . The forward wall  114  includes an outlet passageway  116  sized and positioned to allow the projectile to pass without contact. The nose piece  112  may also include tool notches  118  similar in design and function to the notches  108  of the second stage nose piece  104 . The nose piece  112  could be adapted to include a secondary flash hider or glass breaking point (not shown). 
     Referring now to  FIGS. 8-13 , a thread protector/retainer cap  120  may be provided. The cap  120  is threaded (at  122 ) to engage the threads  26  of the second stage  14  and the threads  26   a  of the first stage nose piece  112 . Because the second stage  14  may be carried in a pouch, pocket, or pack when separated from the first stage  12 , use of the retainer cap  120  will protect the otherwise exposed attachment threads  26 . Because the threads  26   a  of the first stage nose piece  114  are the same as those  26  on the second stage  14 , the nose piece and the retainer cap  120  can likewise be coupled. 
     The retainer cap  120  may include external knurling  126  or flats to enhance grip. If desired, a lanyard attachment  124  on the retainer cap  120  allows it to be secured to a pack or vest. The first stage nose piece  104  and the second stage  14  cannot be in use at the same time. So, a lanyard attachment prevents loss and provides easy retrieval not only of the cap  120 , but also of the second stage  14  and nose piece  114  when stowed in a pack, pouch, or pocket. The lanyard attachment  124  may be a simple loop or through-hole that allows a cord or hook to be secured. Or, the attachment  124  may be in the form of a sling swivel stud (as generally shown), quick-detach single-point sling socket/stud, or any other suitable attachment device or means. 
     In some jurisdiction, such as the United States under current law, it is important that a modular suppressor not have parts that are separately attachable to a firearm. In this regard, the second stage  14  of the illustrated embodiment cannot be used separately from the first stage  12  and the parts cannot be interchanged or reconfigured, other than as one single-stage or one multi-stage suppressor. 
     Referring now also to  FIGS. 10 and 11 , the illustrated suppressor  10  may be completely disassembled for internal cleaning or servicing. Typically, modern centerfire ammunition is clean enough that routine internal cleaning is unnecessary. Threaded connections  25 ,  30 ,  40 ,  42 ,  106 ,  110  within each stage  12 ,  14  may be sealed with a heat-resistant thread-locking or thread-sealing adhesive compound (such as Loctite™ or Rockset™) so that any servicing other than configuring the suppressor in one or two stages is not done in the field and is done only by an armorer, a gunsmith, or the manufacturer. 
     While one or more embodiments of the present invention have been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. Therefore, the foregoing is intended only to be illustrative of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended to limit the invention to the exact construction and operation shown and described. Accordingly, all suitable modifications and equivalents may be included and considered to fall within the scope of the invention, defined by the following claim or claims.