Abstract:
A silencer for a firearm which incorporates a cylindrical housing, front end cap, mean of attachment to the muzzle of a firearm, spacers and an improved cone baffle design. The proposed device incorporates a novel cone baffle design which uses concave flutes to increase surface area and thereby sound reduction. The geometry of this new cone baffle minimizes the weight of a silencer, maximizes internal volume, and effectively reduces sound and flash which are the result of a discharging firearm.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention relates in general to a sound suppressing device for reducing the muzzle blast and muzzle flash that occurs during the discharge of a firearm, and in particular, to such a device comprised of a type including an outer tube housing having at least one baffle which is conical in design. 
     2. Prior Art 
     Firearms when discharged produce a high intensity impulse sound. To reduce this high intensity impulse sound, many different silencers for firearms have been developed and patented. Combusting powder exiting the silencer produces a bright flash. Reducing or eliminating the flash is another goal of silencer manufacturers. 
     A wide variety of techniques have been developed and patented to produce effective silencers. The most efficient silencers have used combinations of baffles and varying sized expansion chambers, and/or liquid media to cool hot expanding gases. Regardless of the techniques used, the aim and intention of a silencer is to delay the exit of the propellant gases from the sound suppressor so that the resulting sound level is significantly reduced. Other concerns such as weight and point of impact shift resulting from the use of a silencer have also become issues of concern for silencer manufacturers. 
     Baffles have been used to achieve high levels of sound reduction in a variety of firearm silencers and the use of complex baffle, spacer combinations or monolithic baffle structures are known in the prior art. Symmetrical baffle designs have been used to reduce the negative effects on accuracy but at the expense of sound reduction. Baffles with asymmetric features which are positioned at an angle to the bore, or have slanted sidewalls have been used to achieve high levels of sound reduction. Cone or conical baffles have been used extensively over many years and a great many variations exist. Cone baffles are used to divide the silencer tube into chambers of various sizes where the expanding gases may expand and cool. Conical baffles may be of a truncated design, a frusto-conical design, or a conical baffle with a spiral vane on the exterior surface of the baffle. Many variations of the basic conical baffle are due to changes in the angle of the conical baffle and the addition of structures to the conical baffle to aid in improving the sound reduction level of the suppressor. Some of these structures have included a flat or curved flange positioned along the exterior surface of the cone. 
     U.S. Pat. No. 3,385,164 (Walther et al) discloses the use of conical baffles that feature a plurality of steps or multiple annular shoulders on the interior surface of a conical baffle. Also disclosed is the use of these multiple annular shoulders on the exterior and interior surfaces of a conical baffle. However, the use of these conical baffles with annular shoulders is in conjunction with other techniques. These conical baffles are positioned and only used in the area of the suppressor closest to the muzzle exit of the suppressor. This particular baffle design is also heavy and does not predict the redirection of gases which is achieved with vertical flutes. 
     One variation of the baffled sound suppressor is known as the coaxial suppressor. One version of the coaxial suppressor uses baffles that are separated by reduced diameter spacers, that are concentric to the bore of the suppressor with the spacers being ported to allow venting of the propellant gases to the outer expansion chamber. Another version of the coaxial suppressor uses a reduced diameter housing containing baffles and spacers, and this is positioned concentrically within an outer housing. Porting of the inner housing allows for venting of the gases to the outer expansion chamber. U.S. Pat. No. 4,576,083 (Seberger) features the use of reduced diameter coaxial spacer elements that are ported between groups of conical baffles. The baffles themselves have conventional spacer elements between each baffle. Each baffle is also ported at varying positions. U.S. Pat. No. 6,575,074 (Gaddini) features baffles that have integral reduced diameter coaxial spacer elements, and these are vented in a specific manner, dependent upon the caliber of the host firearm. The baffle featured in the Gaddini patent has a small conical portion that fits within the reduced diameter coaxial spacer element when assembled. The bore aperture is provided with an elongated slot. The use of coaxial spacing with silencers results in a silencer significantly heavier than designs which do not utilize this method. When the spacer must act as a support wall for the baffle, without the support of the external housing wall the result is a thicker spacer which weighs more than would be necessary with designs that do not utilize coaxial spacing. 
     It is an object of the invention herein described to provide a firearm silencer which eliminates muzzle flash and substantially reduces the sound signature of the host firearm through the use of cone baffles with fluted surface structures and either symmetrical or asymmetrical cuts on the tip of each cone which in turn has minimal or no effect on the accuracy of the discharged projectile. The use of stampings allows for the incorporation of surface geometry not seen before. With proper alloy selection, the internal volume of a silencer is increased because the stamped cone baffles used in one embodiment of the herein disclosed invention are much thinner. This change used in conjunction with the novel surface structures results in weight reduction, increased sound reduction, and the virtual elimination of muzzle flash. 
     Additional objects, advantages, and novel features of the invention will be set forth in part in the description as follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. 
     OBJECTS AND ADVANTAGES 
     Accordingly, several objects and advantages of the present invention are:
         (a) To provide a conical baffle design, which when used as part of a silencer assembly, significantly reduces the impulse sound of a discharged firearm.   (b) To provide a conical baffle design that may be used as part of a silencer assembly to reduce or eliminate the muzzle flash which is the result of hot, expanding gases that follow as a result of a firearm being discharged.   (c) To provide vertical fluted surfaces on a conical baffle which increase surface area and therefore increase sound and flash reduction.   (d) To increase the internal volume of a silencer without increasing its external diameter thereby increasing its sound reduction capability.       

     Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
     SUMMARY 
     The present invention is a silencer for a firearm which is intended for reducing the sound and flash signature of the host firearm. The silencer comprises a cylindrical housing, a mount, with means for attachment to a firearm and to the cylindrical housing, a front end cap with means for attachment to the cylindrical housing, and at least one fluted conical baffle positioned within the housing and between the mount and front end cap of the silencer. Separate spacer elements having an external diameter less than or slightly less than the internal diameter of the cylindrical housing are positioned between the mount and front end cap of the silencer and the plurality of fluted conical baffles. These spacers provide support and positioning of the baffles within the cylindrical housing of the silencer. The circular front end cap of the silencer is provided with a circular hole therein for the projectile to pass through the front end of the silencer. Expansion chambers are formed between the mount and front end cap of the silencer and the baffles within the silencer. 
     In one embodiment, the silencer utilizes a plurality of conical baffles that are provided with a concentric hole for a discharged projectile to pass. The conical baffles are also provided with a plurality of flutes spaced evenly about the exterior of the baffles, the depth of these flutes is deepest at the center of the longitudinal path which they occupy on the exterior of the conical baffle. 
     In another embodiment, the silencer features a combination of conical baffles, with at least one baffle having a step. A step is produced on the apex of a conical baffle by removing half of the apex. This step redirects the expanding gasses gases from a discharging firearm effectively creating turbulence and increasing the sound and flash reduction of the herein described silencer. 
    
    
     
       DRAWINGS 
       The novel features believed to be characteristic of the invention, together with further advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which one embodiment of the present invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. 
         FIG. 1  shows a top plan view of a conical baffle in accordance with an embodiment of the present invention; 
         FIG. 2  shows a side plan view of the baffle of  FIG. 1 ; 
         FIG. 3  shows a bottom view of the baffle of  FIGS. 1-2 ; 
         FIG. 4  shows a side sectional view of the baffle of  FIG. 3  taken along line  4 - 4 ; 
         FIG. 5  shows a longitudinal sectional view of a silencer in accordance with an embodiment of the present invention; 
         FIG. 6  shows a side view of a firearm with a threaded muzzle; 
         FIG. 7  shows a side view of the firearm of  FIG. 6  coupled to a silencer in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Turning now to the drawings in which like reference characters indicate corresponding elements throughout the several views, attention is directed to  FIG. 5  which illustrates an embodiment of a silencer  30 . The silencer  30  may include a mount  31  which serves as a means to secure the silencer  30  to the host firearm  40 . Mount  31  uses threads to removably secure the silencer  30 , and is located on the proximal end of the silencer assembly. The distal front end of the silencer  30  may include a front end cap  32 . A cylindrical tube  33  is utilized as a housing for the silencer  30 . The internal volume of the silencer  30  is occupied by a combination of baffles  20  and spacers  34 . 
     The front end cap  32  has a centrally located aperture  35  through which a bullet may pass. 
     In one embodiment, welds may be used to secure the mount  31  to the spacers  34 , baffles  20 , and front end cap  32 . The tube  33  may then be slid over this sub assembly and welded to the mount  31  and front end cap  32 . The baffles may be positioned so that the apex  24  of the baffle  20  is facing the proximal end of the silencer  30 . A spacer  34  separates the mount  31 , baffles  20 , and front end cap  32  from each other. In another embodiment, threads may be used to assemble the silencer  30 . 
     As used herein, the word “front” or “forward” or “distal” corresponds to the firing direction of the firearm (i.e., to the right as shown in  FIGS. 5 &amp; 6 ); “rear” or “rearward” or “back” or “proximal” corresponds to the direction opposite the firing direction of the firearm (i.e., to the left as shown in  FIGS. 5 &amp; 6 ); “longitudinal” means the direction along or parallel to the longitudinal axis of the silencer  30 ; and “transverse” means a direction perpendicular to the longitudinal direction. 
     In  FIGS. 1-4 , there are illustrated several views of one embodiment of the baffle  20  used in conjunction with the silencer  30 . The exterior of the baffle  20  has a series of flutes  21  which are concave. The flutes  21  while numbering eight in  FIGS. 1-4  should not be construed as representative of the only number or style of flutes  21  which may be used with the proposed baffle  20  design. The ledge  23  of the baffle  20  provides a surface which allows the baffles  20  to be supported by the spacers  34  within the silencer  30 , as illustrated in  FIG. 5 . In one embodiment, the ledge  23  may also serve as a weld point during assembly of the silencer  30 . Centrally located on the baffle  20  is a circular aperture  22  which serves as a passage point for a bullet being discharged from the host firearm  40  (shown in  FIGS. 6-7 ). 
     In  FIG. 6 , there is illustrated a view of a firearm  40  with a barrel  41  and a threaded muzzle  42 . The firearm  40  depicted is an M4 carbine which is in service with the US military. The principles of the present invention were tested through the use of a prototype silencer coupled to an M4 carbine as depicted in  FIGS. 6-7 . 
     In  FIG. 7 , there is illustrated a view of a firearm  40  with the silencer  30  threadedly secured to the threaded muzzle  42  of the barrel  41 . 
     Immediately following the discharge of a firearm  40  expanding gases from the barrel  41  pass through the mount  31  and into the initial expansion chamber  50 , as formed between the mount  31  and the first baffle  20  as illustrated in  FIG. 5 . Gas passes through the aperture  35 , provided on each of the baffles  20 , to fill each successive expansion chamber  51 - 54  where the baffles  20 , spacers  34 , and tube  33  form the whole of the individual chambers. An expansion chamber  54  is sandwiched between a baffle  20  and the front end cap  32 . This is the final chamber prior to the gases passing into the atmosphere. As the gases from the discharged firearm  40  pass over each baffle  20  into an expansion chamber  51 - 54  the flutes  21  on the baffles  20  increase turbulence and surface area forcing the gases to expend more energy to flow through the aperture  35  provided on the baffle  20  into the next expansion chamber  51 - 54 . The conical shape of the baffles  20  causes the expanding gases being forced into the silencer  30  to initially bypass the baffles&#39;  20  aperture  22  and fill the entire volume of the initial expansion chamber  50 . As the gases expand in the initial expansion chamber  50  gas is forced to the sides of the aperture  22  and passes over the flutes  21 . As the initial expansion chamber  50  is filled the gases then begin to travel back towards the aperture  22 , thru it into the next expansion chamber  51 - 54 . This process is repeated as the gases pass through each expansion chamber  51 - 53 . 
     The number of baffles  20  may be selected to optimize the dwell time necessary to slow the unburned powder trapped in the expanding gases. Caliber of the host firearm  40  will be one of the most significant factors when determining the number of baffles  20  placed in the silencer  30 . By slowing down the expanding gases and thereby the unburnt powder the silencer  30  is preventing the combustion of the powder once it hits the oxygen rich environment outside of the silencer  30 . Muzzle flash and sound are reduced by preventing said unburnt powder from combusting. 
     Conclusion, Ramifications, and Scope 
     Accordingly, the reader will see that, according to the invention, I have provided an improved cone baffle  20  with a plurality of flutes  21  located about its periphery. I have afforded the user of a silencer equipped with said baffles improved noise reduction, flash suppression, and reduced weight of the overall package. This new improved fluted baffle  20  may be incorporated into virtually any silencer design. This baffle  20  design is not limited to any specific mounting system or method of assembly as the flutes  21  may be incorporated onto any baffle  20  which is conical in design. 
     While my above drawings and description contain many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one embodiment thereof. For example, my design is not limited to the use of four baffles  20  with five expansion chambers  50 . The herein described design is merely one embodiment of the proposed invention. The number of baffles  20  used may be selected based on weight restrictions, caliber of firearm being silenced and ammunition choice for example. Another possibility is increasing the size of the expansion chambers  50 - 54  by lengthening the spacers  34  and the tube  33  to provide more internal volume for each expansion chamber  50 - 54 . Increased volume provides more area for the expanding gases to be contained prior to exiting the silencer. The increased dwell time of the gases within the silencer  30  tube can aid in sound and flash reduction. 
     Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.