Patent Publication Number: US-10330416-B2

Title: Interchangeable chamber and barrel system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of U.S. application Ser. No. 15/401,583 filed on Jan. 9, 2017, which is a continuation of U.S. application Ser. No. 14/601,545 filed on Jan. 21, 2015 now issued as U.S. Pat. No. 9,541,343. Each of the aforementioned patent applications, and any applications related thereto, is herein incorporated by reference in their entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable to this application. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates generally to a firearm barrel and more specifically it relates to an interchangeable chamber and barrel system for allowing an end user to easily change a chamber body and/or a barrel for a firearm without the assistance of a gunsmith. 
     Description of the Related Art 
     Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field. 
     A conventional gun barrel is an elongated single piece of metal with a chamber that receives the ammunition cartridge and a bore that receives the fired bullet of the ammunition. The barrel of a rifle becomes damaged after repeated firings due to various factors including the heat generated to propel the bullet through the bore of the barrel and wear by the bullet passing through the bore. After repeated usage, the rifling in the bore is diminished thereby reducing the accuracy of the rifle. When the rifling in the bore has deteriorated, the barrel is often times referred to as “shot out”. In addition, cracks, pits and fissures can develop at the rear end of the bore where the heat is the most intense. This area is sometimes referred to as the “throat” of the barrel. If the user wants the rifle to shoot accurately at a target, the barrel needs to be replaced. In addition, if the user of the rifle wants to change the caliber of bullet fired they need to replace the barrel with one that has the appropriate sized chamber and bore. 
     To replace a rifle barrel and/or change a chamber, a gunsmith is needed to machine the barrel to fit the action and to cut the chamber in the barrel itself. Hence, replacing a rifle barrel is expensive and time consuming depending upon the backload of work the gunsmith has which is sometimes 6 months to 12 months. The end user of the rifle is therefore not able to use the firearm until the new barrel is fabricated and installed by the gunsmith. 
     To further complicate matters, it is difficult for a gunsmith to accurately machine a chamber and a bore into a barrel. Since the throat of the bore has to be cut one or more inches into the barrel because of the chamber, it is difficult to maintain concentricity between the throat of the bore and the chamber because cutting into the barrel several inches often times cuts off center because bores typically have a curvature to them. Because of the resulting curvature of the bore and the throat of the bore, the barrel has a decreased accuracy and increased inconsistency. Furthermore, because the curvature of the bore is different for each gun barrel, a new barrel will not shoot the same as the prior barrel on the firearm. 
     In addition, machining costs for a new gun barrel are higher for a gunsmith because they are not able to use a CNC (computer numerical control) machine for machining the chamber. In addition, if the barrel, the bore and/or the chamber is damaged during the machining of the gun barrel, the entire gun barrel must be discarded resulting in wasted material and time. 
     Because of the inherent problems with the related art, there is a need for a new and improved interchangeable chamber and barrel system for allowing an end user to easily change a chamber body and/or a barrel for a firearm without the assistance of a gunsmith. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention generally relates to an interchangeable chamber and barrel system which includes an interchangeable chamber body having a chamber that is removably connectable to a receiver of a firearm and an interchangeable barrel that is removably connected to the chamber body opposite of the receiver. The chamber body and/or the barrel may be changed on the firearm at any time based on the preference of the end user. There has thus been outlined, rather broadly, some of the features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and that will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is an upper perspective view of the present invention fully assembled as part of a firearm. 
         FIG. 2  is an exploded upper perspective view of the present invention with respect to a firearm. 
         FIG. 3  is an upper perspective view of the chamber body illustrating the outer opening. 
         FIG. 4  is an upper perspective view of the chamber body illustrating the opening to the chamber. 
         FIG. 5  is a side view of the chamber body. 
         FIG. 6  is an end view of the chamber body illustrating the outer opening. 
         FIG. 7  is an end view of the chamber body illustrating the chamber. 
         FIG. 8  is a cross sectional view taken along line  8 - 8  of  FIG. 7 . 
         FIG. 9  is an upper perspective view of the barrel illustrating the inner end and the bore. 
         FIG. 10  is an upper perspective view of the chamber body attached to the barrel. 
         FIG. 11  is a cross sectional view taken along line  11 - 11  of  FIG. 1 . 
         FIG. 12  is a magnified cross sectional view of  FIG. 11  illustrating the chamber body connected to the receiver and the barrel. 
         FIG. 13  is a magnified cross sectional view of  FIG. 11  illustrating an ammunition cartridge within the chamber of the chamber body. 
         FIG. 14  is a magnified cutaway view of an alternative embodiment of the chamber body attached to the barrel with a pressure ring to seal the connection. 
         FIG. 15A  is an exploded, cross sectional view of the chamber body, the pressure ring, and the barrel. 
         FIG. 15B  is an exploded view of the chamber body, the pressure ring, and the barrel. 
         FIG. 16  is an end view of an alternative embodiment of the chamber body illustrating a ring groove. 
         FIG. 17  is an end view of an alternative embodiment of the barrel illustrating a ring groove. 
         FIG. 18  is a magnified, cross sectional view of the chamber body, the pressure ring, and the barrel of an alternative embodiment. 
         FIG. 19  is a perspective cutaway view of an alternative embodiment of the chamber body attached to the barrel with a pressure ring to seal the connection. 
         FIG. 20A  is a perspective view of a pressure ring that can be used with an alternative embodiment. 
         FIG. 20B  is a magnified, cross sectional view of a pressure ring that can be used with an alternative embodiment. 
         FIG. 21  is cross sectional view illustrating an ammunition cartridge within the chamber of an alternative embodiment of the chamber body. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A. Overview. 
     Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views,  FIGS. 1 through 21  illustrate an interchangeable chamber and barrel system  10 , which comprises an interchangeable chamber body  20  having a chamber  24  that is removably connectable to a receiver  14  of a firearm and an interchangeable barrel  30  that is removably connected to the chamber body  20  opposite of the receiver  14 . The chamber body  20  and/or the barrel  30  may be changed on the firearm at any time based on the preference of the end user. The chamber body  20  is preferably constructed of a first unitary piece of metal and the barrel  30  is preferably constructed of a second unitary piece of metal that is manufactured separate of the first unitary piece of metal. It is further preferable that the chamber body  20  and the barrel  30  are manufactured using a CNC machine to assist in reducing manufacturing costs. In an example embodiment, a pressure ring  40  can be positioned in channels or grooves  41 ,  42  in the adjacent ends of the chamber body  20  and the barrel  30 , respectively, to create a tight seal between the components and to prevent or reduce wear or damage to the barrel  30  or chamber body  20  during assembly or disassembly. The pressure ring  40  is compressed within the grooves when the barrel  30  and chamber body  20  are screwed together. 
     The present invention may be utilized with various types of firearms including, but not limited to, rifles, pistols and shotguns. The present invention may also be utilized in bolt  18  action, lever action, pump action, revolver or semi-automatic types of firearms. The present invention may also be utilized with various types of gun barrels  30  including, but not limited to, smoothbore  33  and rifled. 
     B. Interchangeable Chamber Body. 
     The chamber body  20  has a first end  22  and a second end  26  as illustrated in  FIGS. 3 through 8  of the drawings. The first end  22  of the chamber body  20  is removably attachable to the receiver  14  of the firearm thereby allowing removal and changing of the chamber body  20  with respect to the rifle. The first end  22  of the chamber body  20  is preferably removably attached to a receiver opening  16  within the receiver  14  as illustrated in  FIGS. 1 and 2  of the drawings. The receiver  14  is attached to the firearm body  12  (e.g. wood, composite, metal) and the receiver  14  houses many of the moving components of the rifle as illustrated in  FIGS. 1 and 2  of the drawings. For example, one type of rifle uses a bolt  18  with a lever that is rotatably and slidably positioned within the receiver  14  to extend an ammunition cartridge  19  into the chamber  24  of the chamber body  20  and to retract the ammunition cartridge  19  from the chamber  24 . 
     The chamber body  20  has an elongated structure with a concentric longitudinal axis. The external cross-sectional shape of the chamber body  20  is preferably circular as best illustrated in  FIGS. 6 and 7  of the drawings, but may have various other types of shapes (e.g. square, rectangular, oval). The length of the chamber body  20  measured from the first end  22  to the second end  26  is at least the length of the chamber  24  combined with the length required for the end connectors which are discussed herein. The chamber body  20  is constructed of a rigid material such as, but not limited to, metal. The chamber body  20  is preferably manufactured using a CNC machine or other efficient machining process. 
     The first end  22  of the chamber body  20  includes a first connector that is adapted to be removably connected to a receiver  14  of a firearm thereby allowing the interchangeability of the chamber body  20  with respect to the firearm. The first connector may be comprised of any connector device suitable for securely attaching the chamber body  20  in a non-movable manner to the receiver  14  of the firearm to prevent movement during firing of the firearm and that also allows for releasing of the chamber body  20  from the receiver  14  when the user desires to change the chamber body  20  on the firearm. It is preferable that the first connector is comprised of a threaded structure that threadably connects to a corresponding threaded structure on the receiver  14 . It is further preferable that the first connector is comprised of outer threading  23  surrounding at least a portion of the first end  22  that is adapted to threadably connect to a corresponding interiorly threaded receiver opening  16  in the receiver  14 . It can be appreciated that an end of the receiver  14  may have exterior threading and the first connector for the first end  22  has interior threading  29  that threadably connect to one another alternatively. 
     The second end  26  of the chamber body  20  includes a second connector that is adapted to be removably connected to an inner connector of the inner end  31  of the barrel  30 , wherein the inner end  31  of the barrel  30  is at the end of the barrel  30  opposite of the muzzle end  35 . 
     The second connector may be comprised of any connector device suitable for securely attaching the barrel  30  in a non-movable manner to the chamber body  20  to prevent movement during firing of the firearm and that also allows for releasing of the barrel  30  from the chamber body  20  when the user desires to change the barrel  30  on the firearm. It is preferable that the second connector is comprised of a threaded structure that threadably connects to a corresponding threaded structure on the receiver  14 . It is further preferable the second connector is comprised of interior threading  29  within the second opening  28  and wherein the inner connector of the barrel  30  is comprised of outer threading  32   23  that threadably connects to the interior threading  29  of the second connector. However, it can be appreciated that the second connector may be comprised of exterior threading surrounding at least a portion of the second end  26  that is adapted to threadably connect to a corresponding interiorly threaded opening in the inner end  31  of the barrel  30 . 
     As shown in  FIGS. 3 through 4  of the drawings, the chamber body  20  preferably includes a plurality of gripping members  21  for selective engagement by a tool such as, but not limited to, a spanner wrench. Various other structures may be used on the chamber body  20  to allow for tightening and removal of the chamber body  20  with respect to the receiver  14  of the firearm. 
     As shown in  FIGS. 14 through 18  of the drawings, the chamber body  20  may also include a channel or ring groove  41  that surrounds the open end of the chamber  24 . The ring groove  41  includes a sealing surface  43  that makes contact with a pressure ring  40 . Sealing surface  43  may be substantially planar and parallel with the inner face of the chamber body as shown in  FIG. 15A . In an example embodiment, the ring groove  41  is annular and concentric with the chamber opening at the face of chamber body  20  adjacent to the inner end  31  of barrel  30  although other configurations are possible. The ring groove  41  is open where the interior face of the chamber body is adjacent to the inner end  31  of the barrel  30 . The ring groove  41  is sized and positioned to receive the pressure ring  40 . The inner end  31  of the barrel  30  has a ring groove  42  that is sized and positioned to receive the other end of pressure ring  40  when the chamber body  20  and barrel  30  are secured, as best shown in  FIG. 18 . The ring groove  42  is open to the interior face of the inner end  31  of the barrel  30 . In an example embodiment, ring grooves  41  and  42  may have substantially rectangular or even square cross sections, although other profiles are possible. 
     Like ring groove  41 , ring groove  42  may be annular and concentric with the bore  33  of the barrel. Also, ring groove  42  includes a sealing surface  44  that makes contact with the pressure ring  40  when the barrel and the chamber body are assembled. The sealing surface  44  may be substantially planar and parallel to the end face of barrel  30 , as shown in  FIG. 15A . Because it is the pressure ring  40  that makes contact and forms a seal between the barrel  30  and the chamber body  20 , there may be a slight gap  45  between the end surfaces of the barrel and the chamber body, as shown in  FIG. 18 .  FIG. 18  shows the ring grooves in the chamber body  20  and the barrel  30  having the same depth and being substantially symmetrical, but it may be appreciated that the grooves may be configured so that the pressure ring  40  or any sealing member can extend further into either the barrel  30  or the chamber body  20 . 
     The pressure ring  40  may be comprised of brass or any other suitable material that is capable of withstanding the temperatures and pressures present when a gun is fired and of forming a good seal. Modern rifle cartridges may create pressures exceeding 50,000 or 60,000 psi, and for certain uses, ammunition in the future is expected to create even greater pressures, such as 100,000 psi or more. The chamber/barrel system disclosed here can withstand such pressures, and has in testing withstood more than 120,000 psi in a blast lab without failure, leaks, or even any damage to the barrel, chamber body, or pressure ring. 
     As shown in  FIGS. 20A and 20B , pressure ring  40  can be quite thick relative to its width, such that its cross section is nearly square, although other proportions are also possible, for example, for uses with different calibers. As best shown in  FIGS. 15A and 20A and 20B , the pressure ring  40  has a chamber-side face  48  and a barrel-side face  49 . Faces  48  and  49  can be substantially parallel in an example embodiment. When the chamber body  20  and the barrel  30  are assembled, the chamber-side face  48  of the pressure ring forms a seal against a sealing surface  43  of ring groove  41 , and the barrel-side face  49  of the pressure ring  40  forms a seal against sealing surface  44  of ring groove  42 . The pressure ring  40  also has an inner surface  47  and an outer surface  48  sized to fit within ring grooves  41  and  42 . 
     When the barrel  30  and chamber body are secured together as described here, there may be a slight gap  45  between their surfaces, as shown in  FIG. 18 . As an example, the gap may be 0.001″, although other gap sizes are possible. The presence of gap  45  ensures that pressure ring  40  is securely in contact with the opposing, sealing surfaces  43  and  44  of ring grooves  41  and  42 . When the barrel  30  and the chamber body  20  are screwed together, the pressure ring is compressed between the components, and specifically, into sealing contact with surfaces  43  and  44 . Accordingly, pressure ring  40  forms a final, gas-tight seal between the chamber body  20  and the barrel  30 . In addition to forming a good seal, the pressure ring within ring grooves  41  and  42  can help align and center the barrel  30  and the chamber body  20 . 
     In an example embodiment, the chamber body  20  and the barrel  30  are reusable, and the pressure ring is inexpensive and replaceable. When the chamber body  20  and the barrel  30  are assembled or reassembled for any reason, a user can install a new pressure ring  40  if needed. As shown in  FIG. 15 , the pressure ring  40  may be a simple ring shape with a rectangular cross section, although other shapes and cross sections are possible. Advantageously, the pressure ring  40  can prevent damage that may be done to either the barrel  30  or the chamber body  20  that could possibly occur with multiple assembly/disassembly operations without using a pressure ring. 
     It is possible to use the same size pressure ring  40  for chamber bodies and barrels in different calibers, so that one or a few different pressure ring sizes can be kept in stock and used for different barrel/chamber caliber combinations. Of course, it is also possible to use different pressure ring sizes as appropriate or desired for smaller or larger caliber components. 
     A first opening  25  extends into the first end  22  of the chamber body  20  as best illustrated in  FIGS. 4 and 7  of the drawings. The first opening  25  has a diameter sufficient to receive the caliber of ammunition cartridge  19  intended to be used on the firearm. A chamber  24  is within the chamber body  20  and is connected to the first opening  25 . The chamber  24  has a size and shape designed to snugly receive the caliber of ammunition cartridge  19  intended to be used on the firearm as best illustrated in  FIGS. 13 and 21  of the drawings. For example, the shoulder of cartridge  19  fits tightly into tapering shoulder  27  of chamber  24 , and the neck  51  of cartridge  19  fits in the neck of chamber  24 . The clearances between these chamber portions and the cartridge are typically a few thousandths of an inch, although for high precision shooting, users sometimes use smaller clearances. The chamber  24  receives at least a portion of the ammunition cartridge  19 . 
     A second opening  28  extends into the second end  26  of the chamber body  20  opposite of the first opening  25 , wherein the second opening  28  is connected to the first opening  25  by the chamber  24 . The second opening  28  extends inwardly to a distal end of the neck of the chamber  24  as illustrated in  FIG. 8 . The diameter of the second opening  28  is preferably larger than a diameter of the neck of the chamber  24  as illustrated in  FIGS. 6 and 8  of the drawings. 
     It can be appreciated that the first opening  25  may be part of the chamber  24  to provide a consistent diameter from the first opening  25  to the body portion of the chamber  24  as illustrated in  FIG. 8 . The chamber  24  further includes a tapering shoulder  27  that reduces the diameter of the passage to the size of the neck of the chamber  24  as further shown in  FIG. 8  of the drawings. The first opening  25 , the chamber  24 , the second opening  28  and the bore  33  of the barrel  30  are concentric when the receiver  14 , chamber body  20  and barrel  30  are connected together. 
     C. Interchangeable Barrel. 
     The barrel  30  has an inner end  31 , a muzzle end  35  opposite of the inner end  31  and a bore  33  extending between the inner end  31  and the muzzle end  35  as illustrated in  FIGS. 2 and 9  of the drawings. The barrel  30  may have various lengths used for various types of firearms such as rifles and pistols. The barrel  30  is preferably constructed of a unitary piece of metal, but various other types of suitable materials may be utilized to construct the barrel  30 . 
     The bore  33  extends through the inner end  31  to the muzzle end  35  of the barrel  30  through a discharge opening  34  that releases the bullet and is preferably concentric with respect to the barrel  30 . The bore  33  has a diameter sized to the caliber of bullet being fired through the bore  33 . The bore  33  of the barrel  30  is preferably rifled having a plurality of helical lands and helical grooves. 
     The barrel  30  is comprised of an elongated structure having a longitudinal axis. The barrel  30  may have various cross sectional shapes such as conventional gun barrels  30 , but it is preferable that the barrel  30  has a circular cross sectional shape. 
     The inner connector may be comprised of any connector device suitable for securely attaching the barrel  30  in a non-movable manner to the chamber body  20  to prevent movement during firing of the firearm and that also allows for releasing of the barrel  30  from the chamber body  20  when the user desires to change the barrel  30  on the firearm. It is preferable that the inner connector is comprised of a threaded structure that threadably connects to a corresponding threaded structure on the receiver  14 . It is further preferable that the inner connector is comprised of outer threading  32  surrounding at least a portion of the inner end  31  of the barrel  30  that is adapted to threadably connect to corresponding interior threading  29  of the second opening  28  within the chamber body  20 . It can be appreciated that the second end  26  of the chamber body  20  may have exterior threading and the inner connector for the inner end  31  of the barrel  30  is comprised of an interiorly threaded opening extending into the inner end  31  of the barrel  30  that threadably connects to the exterior threading. 
     D. Operation of Preferred Embodiment. 
     In use, the user selects the desired caliber of ammunition cartridge  19  they desire to fire and the desired length of barrel  30  to use for their firearm. The user then connects the barrel  30  in a threaded manner to the chamber body  20  as illustrated in  FIG. 10  of the drawings. The user then connects the chamber body  20  (along with the barrel  30 ) in a threaded manner to the receiver  14  using a tool. It can be appreciated that the chamber body  20  may be first attached to the receiver  14  followed by the barrel  30  being attached to the chamber body  20 . Once the chamber body  20  is fully secured to the receiver  14  of the firearm, the user is able to insert an ammunition cartridge  19  within the chamber  24  and fire the ammunition cartridge  19  thereby forcing the bullet through the bore  33  of the barrel  30 . 
     After repeated usage, the bore  33  of the barrel  30  may become worn and require replacement. The user simply purchases a new barrel  30 , removes the original barrel  30  from the chamber body  20 , and then installs the new barrel  30  onto the chamber body  20 . In addition, the chamber body  20  may become worn or damaged requiring replacement. Similar to replacing the barrel  30 , the user purchases a new chamber body  20 , removes the old chamber body  20  from the receiver  14  of the rifle and the barrel  30 , and then installs the new chamber body  20  between the receiver  14  and the barrel  30 . When a new barrel, a new chamber body, or both are assembled, a new pressure ring  40  may be used to provide a seal between the barrel  30  and the chamber body  20 . These processes may be used to replace the barrel  30  and/or the chamber body  20  at any time for any reason. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described above. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety to the extent allowed by applicable law and regulations. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive. Any headings utilized within the description are for convenience only and have no legal or limiting effect.