Patent Publication Number: US-11022396-B2

Title: Rifle barrel vibration dampener and method of use

Description:
The present application relates to, and claims priority from, provisional application U.S. 62/888,538, filed Aug. 18, 2019. The disclosure therein, incorporated by reference. 
    
    
     SUMMARY OF THE INVENTION 
     The disclosure of the present invention relates to rifle barrel vibration dampeners and more specifically to a vibration dampener configured to be fitted onto a rifle barrel to reduce barrel harmonic vibration and to improve overall accuracy. 
     As commonly known in the art, each rifle barrel is unique, having different performance characteristics including variation due to the barrels harmonic frequency, or the unique vibration waveform created in the barrel when the gun is fired with a specific round of ammunition. The harmonic frequency can be affected or altered by changing the mass, or the grains, of the bullet, by the type and amount of propellant used which changes muzzle exit velocity, or myriad combinations of the two. Precision shooters or hunters who demand extreme accuracy normally choose hand loaded ammunition where steps such as, case preparation, primer choice, propellant type, propellant volume, bullet shape, bullet grains and depth of the bullet seat are all carefully controlled to insure top performance and accuracy. However, even with stringent loading controls, a slight variation in ammunition performance will cause the harmonic frequency of a barrel to move a shot away from an acceptable bullet grouping. 
     Rifle manufacturers and custom rifle builders have used numerous methods to control the amplitude of barrel harmonic frequency in order to produce consistent shot groupings, including producing over-sized “bull” barrels, fluted barrels and barrels having windings comprised of composite fibers, such as fiberglass, graphite and Kevlar. However, these solutions can add significant weight to the rifle and/or tend to be expensive aftermarket options. 
     What is needed is an inexpensive, lightweight solution to control the amplitude of the harmonic frequency of a rifle barrel and improve shot accuracy. 
     A first embodiment of the present invention is a simple, high durometer and high tensile strength, sleeve configured to be securely fitted on the barrel of rifle and reduce the harmonic frequency of the barrel. The sleeve can be configured to fit over the barrel between the muzzle and the rifle forestock; covering only a portion of the barrel or the portion of the barrel with the highest propensity for vibration or movement. The sleeve can be configured to cover approximately one-quarter to one-half of the overall barrel length, with a preferred embodiment where the sleeve covers approximately one-third of the overall barrel length. The sleeve can be formed using a poly olefin, such as, but not limited to, polyethylene or polypropylene. The sleeve may be thermoplastic in one embodiment, and may have an inside diameter slightly smaller than the outside diameter of the rifle barrel. The sleeve can be carefully heated to a normalized temperature where the sleeve expands to fit over the rifle barrel and then heated to a fitting temperature where the sleeve contracts securely around the outside diameter of the barrel. 
     In a second embodiment the sleeve is formed using a thermoplastic sleeve having a diameter slightly larger than the outside diameter of the rifle barrel. After the sleeve is placed over the muzzle and into position on the barrel, the sleeve can be carefully heated in an oven or heated using a heat gun to shrink the sleeve evenly and securely around the barrel. 
     In yet another embodiment the sleeve can be configured using an elastomeric material such as neoprene or silicone rubber and having a diameter, again slightly smaller than the outside diameter of the barrel. The sleeve is stretched in order to be fitted over the barrel. In one embodiment the sleeve can be lubricated using a “non-reactive” lubricant such as liquid silicone in order to aide ease of installation and to prevent oxidization or corrosion of the barrel under the sleeve. It is contemplated that pressurized air may be used when installing an elastomeric sleeve. 
     In another embodiment of the present invention, the vibration dampener sleeve is configured to cover the full length of the rifle barrel from the muzzle to the end of the chamber. In this embodiment it is necessary for the rifle to be disassembled prior to fitting the vibration dampener sleeve onto the barrel. Once the dampener sleeve has been fitted onto the barrel, the rifle can be re-assembled and the barrel and stock clearance can be adjusted. 
     In yet other embodiment an internal insulating material may be used in order to again improve shot performance and to reduce perceived vibrations felt by the user. In one embodiment, the interior of the sleeve can be coated with a uniform film of insulating material such as elastomeric silicone. The silicone layer will remain between the sleeve and the rifle barrel after installation and will further reduce the amplitude of the harmonic frequency of the barrel. The silicone layer will seal any space between the barrel and the sleeve and may also include corrosion inhibitors to preserve the barrel finish under the sleeve. 
     In another embodiment a silicone sublayer can be applied as internal ribs or ribbons to the interior the vibration damping sleeve. It is contemplated that a free space is left between each internal rib to allow for uniform coverage of the barrel after the thermoplastic sleeve has been shrunk and fitted. 
     It is recognized that the wall thickness of the vibration dampener is greater than an esthetic film and has enough tensile strength and rigidity to control the harmonic frequency amplitude of the rifle barrel. The wall thickness of the vibration dampener sleeve is less than 1/10 of dimension for the outside diameter of the sleeve. 
     The outside surface of the vibration dampening sleeve can include ornamentation to reduce barrel glare, to provide camouflage or a faux finish to simulate a pattern on the stock, to simulate a composite, simulate metal or any other desired finish which can be applied to a plastic surface. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The following description of the embodiments can be understood in light of the Figures, which illustrate specific aspects of the embodiments and are part of the specification. Together with the following description, the Figures demonstrate and explain the principles of the embodiments. 
         FIG. 1  a side view of a rifle including the vibration dampener of the present invention, 
         FIG. 2  an assembly view of a vibration dampener, 
         FIGS. 3A and 3B  detail view of a vibration dampener, 
         FIGS. 4A and 4B  perspective views of embodiments of a vibration dampener, 
         FIG. 5A  an end view of a vibration having an interior insulating film, 
         FIG. 5B  an end view of a vibration dampener including interior insulating ribs, and, 
         FIGS. 6A and 6B  are example targets showing the benefit of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The following description of the embodiments can be understood in light of the Figures which illustrate specific aspects of the embodiments and are part of the specification. Together with the following description, the Figures demonstrate and explain the principles of the embodiments. In the Figures the physical dimensions of the embodiment may be exaggerated for clarity. The same reference numerals or word descriptions in different drawings represent the same element, and thus their descriptions may be omitted. 
     A first embodiment of the present invention or rifle barrel vibration dampener  100  is shown installed on a rifle  500  having a barrel portion  510  and stock  520 . 
     Illustrated in  FIG. 2  includes a vibration dampener  100  configured to extend the full length of the rifle barrel  510 , extending from the muzzle  511  to the end of the chamber  512 . This configuration provides harmonic frequency dampening control over the entire length of the barrel  510 , however, it is recognized that installation of the full length dampener  100  requires disassembly of the rifle  500  separating the barrel  510  from the stock  520 . The stock  520  includes a forestock  521  and buttstock  522 . The barrel  510  is attached the action  513 . The action  513 , may be a bolt action as shown, lever action, pump action, break action, rolling block, semi-automatic or automatic. 
       FIGS. 3A and 3B  are one embodiment of the present invention or rifle barrel vibration damper, or vibration dampening sleeve  100 . The sleeve  100  including an outside diameter  110 , inside diameter  120 , inside opening or void  130 , end portion  140  and side portion  150 . The inside diameter  110  is configured to securely fit over the outside diameter of a rifle barrel  510  and the length of the side portion  150  will reflect the desired amount of the barrel  510  which is covered by the sleeve  100 . It is contemplated that sleeve  100  will cover at least ¼ of the rifle barrel  510  and up to the full length of the rifle barrel  510 . Sleeve wall thickness  111  is less than 1/10 of the outside diameter  120 . 
       FIG. 4A  is first embodiment of the present invention or rifle barrel vibration dampener sleeve  100  composed of a thermoplastic material such as, but not limited to, polyethylene or polypropylene. 
     The vibration dampener sleeve  100  shown in  FIG. 4B  is composed of an elastomeric material such as neoprene, silicone or rubber and is configured to be stretched over the rifle barrel  510 . 
     Each of the  FIGS. 5A and 5B  show a vibration dampener sleeve  100  including an outside diameter  110 , inside diameter  120 , wall thickness  111 , interior void  130  and including an insulating material  121  configured to further reduce the harmonic frequency amplitude of the rifle barrel  510 . 
       FIG. 5A  includes insulating material  121  or a substantially uniform elastomeric film configured to uniformly cover the rifle barrel  510  which is under the vibration dampener sleeve  100 . The insulating material  121  shown in  FIG. 5B  is installed on the inside diameter  121  of sleeve  100  in radially uniform ribs or ribbons providing uniform coverage once a thermoplastic sleeve  100  is shrunk to size around a rifle barrel  510 . 
       FIGS. 6A and 6B  are by way of example and show rifle targets  600  including a shot group  601 . Shot  602  shown in  FIG. 6B  indicates a potential anomalous shot from an inconsistent round fired through a non-harmonically vibration dampened barrel  510 . 
     It is to be understood that the above mentioned arrangements are only illustrative of the application of the principles of the present disclosure. Numerous modifications or alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present disclosure and the appended claims are intended to cover such modifications and arrangements. Thus, while the present disclosure has been shown in the drawings and described above with particularity and detail, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made without departing from the principles and concepts set forth herein.