Patent Application
20080173166
The present invention relates generally to a shotgun choke. More particularly, the present application involves a shotgun choke arranged with a series of ports in such a manner to reduce muzzle rise when discharging the shotgun. The shotgun choke will also function to reduce actual and perceived recoil when discharged.
A choke is a tapered constriction of the bore of the barrel of a shotgun. The amount of constriction is the difference between the diameter of the bore of the barrel and the diameter of the exit of the choke. The choke is located at the muzzle of the barrel and its presence acts to force the shot of a shotgun into a tighter stream upon exiting. Chokes can be provided in order to achieve a desired shot pattern for a particular purpose. For example, a skeet shooter may use a choke to achieve a desired shot pattern at a particular distance while a trap shooter may use a different choke to achieve the same shot pattern but at an increased distance. One may experiment with different chokes in order to achieve a shot pattern that is as large as possible without having the shot spaced too greatly so that the target is not killed or broken.
A choke can be integrally formed into the barrel of a shotgun during its manufacture. Here, the end of the barrel can be squeezed a desired amount through the use of a tool such as a mandrel. Interchangeable chokes are also known which can be attached to and removed from the barrel of the shotgun. Interchangeable chokes may have internal threading that engages external threading located on the barrel. Alternatively, the interchangeable choke may have external threading. In such an instance, the barrel of the shotgun can include internal threading configured to engage external threading on the interchangeable choke when recessed therein.
Chokes can be provided with various features to improve the performance of the shotgun to which they are attached. For example, the bore of a choke may include blades or other features that act to score the wad as it passes through the bore. Scoring of the wad facilitates its rapid opening upon exiting the choke so that the wad does not interfere with the string of pellets as they travel to their target. It is also known to employ chokes that have ports that function to expel firing gases out of the bore of the choke. Diffusion of firing gases in this manner acts to dissipate heat during firing and prevents temperature elevation of the choke after multiple shots are fired. The release of gases from the ports functions to reduce both the actual and perceived recoil of the shotgun. Actual recoil is the force directed back to the user upon discharge of the shotgun. Perceived recoil is what the shooter feels or experiences when the shotgun is discharged and can vary from shooter to shooter. Perceived recoil may be dependent upon the way in which the shooter holds the shotgun, the position from which the shotgun is fired, and the height and body type of the user. The ports are located around the circumference of the choke and are radially symmetrical with respect to a longitudinal axis of the bore. Ports are provided in a radially symmetrical manner since manufacturing differences exist between threading of chokes and barrels so that a top dead center position cannot be attained.
Shotguns have a tendency to rise upwards upon their discharge. The upwards rise of a shotgun results in having the butt of the shotgun placed against the shoulder of the user at a location vertically below the discharge point of the shot. The difference in this vertical distance creates a moment when a force is created at the exit of the barrel of the shotgun during discharge to cause the shotgun to rise. After taking a shot, the user must then spend some amount of time repositioning the shotgun for any subsequent shot. Chokes that employ ports act to diffuse the energy of the shot radially outwards and hence less force is directed linearly which causes a lesser moment and hence upwards rise to be realized. Although such chokes are effective at reducing the amount of linear force, they do not direct the firing gases in a location so as to counteract the resulting upward rise as the ports are arranged in a radially symmetrical manner about the entire circumference. As such, there remains room for variation and improvement within the art.
Various features and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned from practice of the invention.
One aspect of one exemplary embodiment provides for a choke for use with a shotgun. The choke includes a body that defines a bore with a longitudinal axis therethrough. The body is configured for engagement with a shotgun so that the bore is positioned for traversal of projectiles of the shotgun therethrough and out of an end of the bore. The body has a circumference and defines at least one port for venting gas from the bore through the circumference. The port is located within a first radial arc that extends 180° about the longitudinal axis. Ports for venting gas from the bore through the circumference are not located within a second radial arc. The second radial arc does not overlap the first radial arc and extends 180° about the longitudinal axis.
Another aspect of one exemplary embodiment resides in a choke as immediately discussed in which the body has external threading located on the circumference. The external threading is configured for engaging complimentary internal threading of a barrel of a shotgun so as to render the body releasably attachable to the barrel.
Also provided in accordance with another aspect of one exemplary embodiment is a choke as described above in which the bore of the body has a conical section and a parallel section. The parallel section is configured for receipt of the projectiles of the shotgun from the conical section and for traversal of the projectiles of the shotgun therethrough and out of the end of the bore.
Another aspect of one exemplary embodiment resides in a choke as mentioned previously in which the circumference is curved in shape.
A further exemplary embodiment in accordance with another aspect is found in a choke as described above in which a plurality of the ports for venting gas from the bore through the circumference are present. The ports are positioned and oriented so as to be bilaterally symmetrical.
A still further exemplary embodiment exists in an aspect as immediately discussed in which the ports are in the shape of slots. The ports have a major axis that is oriented in the longitudinal direction of the body.
Another aspect in accordance with another exemplary embodiment is found in a choke as described above in which the ports are in the shape of slots. The slots each have a major axis that is oriented at an angle to the longitudinal direction of the body.
An additional aspect in accordance with another exemplary embodiment is found in a choke for use with a shotgun that has a body that defines a bore therethrough. The body has a mounting segment for engagement with a barrel of a shotgun so that the mounting segment is located inside of the barrel when engaged. The body has a choking segment that is located outside of the barrel when the mounting segment is engaged with the barrel. The choking segment has a circumference that is curved in shape. The circumference of the choking segment has an upper half and a lower half. The upper half of the circumference is located above the lower half of the circumference when the mounting segment is engaged with the barrel. The body defines at least one port for venting gas from the bore through the upper half of the circumference when the shotgun is discharged. The lower half of the circumference is configured for preventing gas in the bore from passing through the lower half of the circumference when the shotgun is discharged.
A further aspect in accordance with an additional exemplary embodiment is found in a choke as immediately described in which the mounting segment has a circumference that is curved in shape and has external threading thereon. The external threading of the mounting segment is configured to engage internal threading of the barrel in order to render the body releasably attachable to the barrel.
A further aspect exits in an exemplary embodiment all ready described in which the bore of the body has a conical shape in the mounting segment. The bore of the body has a constant diameter throughout the choking segment.
Another aspect of one exemplary embodiment resides in a choke as described above in which a plurality of the ports for venting gas from the bore through the upper half of the circumference are present. The ports are positioned and oriented so as to be bilaterally symmetrical with respect to a plane through a longitudinal axis of the bore and perpendicular to a plane passing through the location of contact between the upper half and lower half of the circumference.
A further aspect in accordance with another exemplary embodiment is found in a choke as immediately described in which the ports are in the shape of slots. The slots have a major axis that is oriented in the longitudinal direction of the body.
Another aspect of one exemplary embodiment is found in a choke as mentioned above in which the ports are in the shape of slots. The slots each have a major axis that is oriented at an angle to the longitudinal direction of the body.
A still further aspect in accordance with another exemplary embodiment includes a choke for use with a shotgun that has a body that defines a bore with a longitudinal axis therethrough. The body is configured for engagement with the barrel of a shotgun so that projectiles of the shotgun are capable of being transferred through the bore and out of an open end of the bore. The longitudinal axis lies in a plane that divides the body into an upper half and a lower half. The body defines at least one port for venting gas from the bore through the upper half of the body to reduce muzzle rise during discharge of the shotgun. The body is configured so that a greater amount of gas is transferred through the upper half of the body from the bore than through the lower half of the body from the bore during discharge of the shotgun.
Also provided in another aspect of an additional embodiment is a method of forming ports in a choke for the purpose of reducing muzzle rise. The method includes the steps of providing a shotgun and a choke. The choke is engaged to the shotgun so that the choke is oriented to have an upper half and a lower half relative to the shotgun once engaged. A reference point is located once the shotgun and choke are engaged with one another. At least one port in the upper half of the choke is formed at a location based on the reference point.
In accordance with another exemplary embodiment a method is provided as immediately discussed in which the reference point is the top dead center.
Another aspect exists in a method as previously discussed in which the forming step involves forming a plurality of ports in the upper half of the choke so that the plurality of ports are arranged symmetrically with respect to the reference point.
A further aspect in accordance with another exemplary embodiment resides in a method as mentioned above that further includes the step of leaving the lower half of the choke without ports.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, which makes reference to the appended Figs. in which:
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the invention.
Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations.
It is to be understood that the ranges mentioned herein include all ranges located within the prescribed range. As such, all ranges mentioned herein include all sub-ranges included in the mentioned ranges. For instance, a range from 100-200 also includes ranges from 110-150, 170-190, and 153-162. Further, all limits mentioned herein include all other limits included in the mentioned limits. For instance, a limit of up to 7 also includes a limit of up to 5, up to 3, and up to 4.5.
The present invention provides for a choke 10 for use with a shotgun 11 that may be beneficial in reducing the amount of muzzle 18 rise upon discharge of the shotgun 11. The choke 10 includes at least one port 38 that functions to vent firing gases 72 from the choke 10 in a direction that counters muzzle 18 rise. Time is thus saved by the user of shotgun 11 in firing subsequent shots as the shotgun 11 need not be repositioned at all or as much due to the elimination or reduction of muzzle 18 rise.
The ports 38 also act to reduce the magnitude of projectile force 20 as a portion of the firing force makes up the downward force 74. The recoil force 22 is likewise reduced in response to the reduction of projectile force 20. The presence of ports 38 thus reduces the recoil force 22 which causes the actual recoil of the shotgun 11 to be reduced. Additionally, the perceived recoil of the shotgun 11 is reduced due to the presence of ports 38. The perceived recoil is the force felt by the user of the shotgun 11 and can vary from user to user due to differences in the body structure of the user, the position in which the shotgun 11 is held during discharge, or the position taken by the user during discharge. For example, the perceived recoil of a user firing from a prone position will be greater than in a standing position. This may be true because in the prone position all of the force of the discharge is directed into the user where as in the standing position the user can sway or move backwards in response to the discharge so as to reduce the perceived recoil of the discharge.
A close-up view of the end of barrel 16 and of the choke 10 is shown in
The choke 10 includes a body 26 that defines a bore 28 therethrough. Bore 28 has a longitudinal axis 30 that may be coaxial with a longitudinal axis of the barrel 16 when the choke 10 is attached to barrel 16. The bore 28 extends from one open end 32 to an opposite open end 34. Open end 32 receives projectiles 70 traveling from the barrel 16. Projectiles 70 are subsequently expelled from the choke 10 through open end 34 of bore 28 to exit the shotgun 11. Choke 10 can be made of a strong material such as high-hardness stainless steel in order to resist deformation due to explosive forces and elevated temperatures that result upon firing projectiles 70 therethrough. Various materials that can be used to construct body 26 along with various wear resistant coatings that can be applied thereto can be found in U.S. Pat. No. 7,140,140 B2, the entire contents of which are incorporated by reference herein in their entirety for all purposes.
Body 26 has a mounting segment 52 and a choking segment 54. The mounting segment 52 and choking segment 54 are located next to one another in the longitudinal direction 56 of body 26. Open end 32 of bore 28 opens into the mounting segment 52 which also includes the external threading 44. The choking segment 54 includes open end 34 of the bore 28 along with one or more ports 38. Bore 28 does not have a consistent diameter extending all the way from end 32 to end 34. Instead, a conical section 48 of bore 28 is present in the mounting segment 52. Bore 28 has a larger diameter at end 32 which tapers to a smaller diameter at the location in which mounting segment 52 contacts choking segment 54. In effect, the conical section 48 of bore 28 narrows as the projectiles 70 traverse therethrough. Conical section 48 functions to constrict the projectiles 70 and thus causes certain desired effects to be achieved. Bore 28 has a parallel section 50 in choking segment 54. Bore 28 has a constant diameter through the parallel section 50 from the point of contact between the choking segment 54 and mounting segment 52 until the end 34 of bore 28. In this regard, the inner wall of choking segment 54 of body 26 has a constant inner diameter. Parallel section 50 of bore 28 may also function to impart a constriction onto projectiles 70 traveling therethrough to achieve certain desired effects.
The shape and length of conical section 48 and parallel section 50 can be varied in order to achieve various results. For example, a steep taper angle of the conical section 48 will cause the shot 78 to quickly compress which may result in a larger shot pattern spread. A flatter taper angle of conical section 48 will cause the shot 78 to compress more gradually and may result in a tighter and more consistent shot pattern. The length of the parallel section 50 in the longitudinal direction 56 of body 26 may also effect the resulting shot pattern of projectiles 70. For example, a larger length of parallel section 50 may cause a more uniform shot column to develop which can create consistently tighter shot patterns. A shorter length in the longitudinal direction 56 of parallel section 50 may cause a larger shot pattern to be produced from parallel section 50. Further, the use of a longer parallel section 50 may increase the benefits realized by the presence of ports 38. As stated, ports 38 cause firing gas 72 to be released which in turn acts to slow down the speed of projectiles 70 upon traversing bore 28. In some instances, the presence of ports 38 function to slow the speed of the wad 76 of projectiles 70 which may be prevent the wad 76 from breaking up a column of shot or pellets 78. Allowing the shot 78 to develop into a column without interference of wad 76 can result in a more desirably consistent shot pattern. Modification of the length of parallel section 50 acts to modify the effectiveness of the ports 38 and thus effects the resulting shot pattern.
Although described as having both a conical section 48 and a parallel section 50, it is to be understood that bore 28 can be variously configured in accordance with other exemplary embodiments. For example, the bore 28 may have a constant diameter from one end 32 to the other end 34. In this regard, the bore 28 is parallel throughout. Alternatively, the bore 28 may be conical from end 32 to end 34. Here, the bore 28 may be larger at end 32 and smaller in diameter at end 34. Further, the diameter of bore 28 may be varied in accordance with various exemplary embodiments to modify the size of the resulting shot patterns. Although described as having a mounting segment 52 and choking segment 54, it is to be understood that the projectiles 70 can be restricted or choked in either one of or both of these segments 52 or 54.
The choke 10 as shown with reference to
A second radial arc 42 extends 1800 about the longitudinal axis 30 and likewise can exist regardless of whether the circumference 36 is curved or flat. The first radial arc 40 and second radial arc 42 may be oriented so that no portion of the first radial arc 40 overlaps a portion of the second radial arc 42. As shown, no ports 38 are present within the second radial arc 42. In accordance with some exemplary embodiments, apertures through the body 26 may be present within the second radial arc 42. For example, a hole within the second radial arc 42 and located through the mounting segment 52 may be used to help hold the mounting segment 52 to the barrel 16, with an associated pin or bolt, in accordance with certain embodiments. In these instances, although an aperture is present in the second radial arc 42 it does not function to vent firing gases from the bore 28 through the body 26.
The ports 38 may be positioned at any location within the first radial arc 40. The ports 38 can be symmetrically or asymmetrically located within the first radial arc 40. Further, other exemplary embodiments exist in which the first radial arc 40 is less than 180°. For instance, the first radical arc 40 can be up to 120°, up to 110°, up to 90°, up to 60°, from 120° to 180°, from 60° to 120°, or from 45° to 160° in accordance with various exemplary embodiments. The second radial arc 42 may consume the remaining arc length about the longitudinal axis 30 or can be otherwise variously sized. In accordance with the aforementioned various embodiments, the first and second radial arcs 40 and 42 do not overlap. Also, in these embodiments, ports 38 can be located in the first radial arc 40 and can be completely absent from the second radial arc 42.
As can be seen upon study of
Longitudinal axis 30 also lies within plane 64 which likewise passes through the body 26 so as to divide body 26 into two halves. Plane 64 is perpendicular to plane 68 and thus acts to divide body 26 into a left side and a right side when oriented for engagement with the barrel 16. The ports 38 can be positioned and oriented so as to be bilaterally symmetrical with respect to plane 64. As such, the design and pattern of ports 38 on either side of plane 64 are mirror images of one another. Body 26 may also have a top dead center 66 which designates a point of body 26 that is at the midpoint with respect to the left right direction when looking straight on when attached to the barrel 16. The top dead center 66 is also located on the circumference 36 and has plane 64 passing therethrough. The top dead center 66 can be found by first engaging choke 10 onto barrel 16 so that the choke 10 is positioned as it would be during operation of the shotgun 11. One may then locate the top dead center 66 and designate it by way of a line or other marking. The ports 38 can then be made a desired arc length distance on either side of the top dead center 66.
Internal threading 46 and other features of the shotgun 11 can vary from shotgun 11 to shotgun 11. As such, the top dead center 66 of a choke 10 may be different when engaged with two different shotguns 11. Therefore, if one were to form ports 38 on a choke 10 with respect to one shotgun 11 engagement of the choke 10 with a subsequent shotgun 11 could result in the ports 38 in an unsymmetrical manner about the top dead center 66. As such, a method of forming the ports 38 in accordance with one exemplary embodiment includes engaging the choke 10 and shotgun 11 and locating a reference point. If threading is used to effect the engagement, the choke 10 can be tightened onto the shotgun 11 until it stops. A certain amount of torque may be applied to the choke 10 and the reference point can be located. In accordance with one embodiment the reference point is the top dead center 66. The reference point may be the bottom dead center or other point in accordance with other embodiments. The ports 38 can then be formed so as to be symmetrical with respect to the top dead center 66. The resulting choke 10 is thus unique to the shotgun 11 and the ports 38 will be properly positioned upon removal and subsequent engagement of the choke 10 and shotgun 11. The choke 10 is not intended to be used with other shotguns 11. Instead, ports 38 will be formed in chokes 10 unique to the other individual shotguns 11. In practice, a user may send his or her shotgun 11 to a manufacture who engages the choke 10 to the shotgun 11 and subsequently forms ports 38. The manufacture will then return both the shotgun 11 and uniquely formed choke 10. It is to be understood, however, that the aforementioned method of locating ports 38 is but one exemplary embodiment and that other methods of forming ports 38 exist. For example, the choke 10 may be made so that it is not unique but may instead be used on multiple shotguns 11.
An alternative exemplary embodiment of the choke 10 is shown in
Another version of the choke 10 is shown in
The choke 10 is thus designed to reduce muzzle 18 rise by ejecting gas 72 in a direction that opposes such muzzle 18 rise. Although described as having no gas 72 ejected through the body 26 out of the lower half 62 of choking segment 54, it is to be understood that other exemplary embodiments exist in which ports 38 are located in the lower half 62 of choking segment 54. In a similar manner, exemplary embodiments exist in which ports 38 are located in the second radial arc 42 in addition to being located in the first radial arc 40. However, in all of these embodiments, the firing gas 72 expelled from ports 38 have a net effect of reducing muzzle 18 rise. For example, the choke 10 may include ten ports 38 in the upper half 60 and four ports 38 in the lower half 62. All of these ports 38 can be of the same size. Although gas 72 is ejected from all of the ports 38, more firing gas 72 is ejected from the upper half 60 so that the net effect of gas 72 discharge functions to reduce muzzle 18 rise. Alternatively, a greater number of ports 38 can be located in the lower half 62 than in the upper half 60. However, the ports 38 may be sized to be larger in the upper half 60 versus the those of the lower half 62 thus causing a greater amount of gas 72 to be discharged therefrom to again function to reduce muzzle 18 rise.
While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
