Abstract:
A rifle apparatus and method wherein the rifle includes a replaceable, threaded, adjustable barrel assembly which is configured for quickly changing the barrel length of the rifle, converting the rifle for using a different caliber of ammunition, and/or accurately determining and quickly setting the headspace in the firing chamber of the weapon for firing the new ammunition. Further, the rifle apparatus preferably also includes a replaceable lower receiver with a well opening and a corresponding magazine retention and release assembly for receiving a magazine clip for the caliber of ammunition fired by the replaceable barrel.

Description:
RELATED CASE 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/101,055 filed Jan. 8, 2015 and incorporates said provisional application by reference into this document as if fully set out at this point. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to rifle apparatuses, systems, assemblies, and methods such as those, by way of example, in the nature of an AK 47 or an AR 15. 
     BACKGROUND OF THE INVENTION 
     A need exists for an improved AK 47-type rifle apparatus, system, assembly, and method which will allow the user to more easily change the caliber and the barrel length of the weapon. 
     SUMMARY OF THE INVENTION 
     The present invention provides an inventive rifle apparatus, system, assembly, and method which satisfy the needs identified above. The inventive rifle (a) can be quickly changed and converted to different calibers and barrel lengths, (b) is modular and ergonomically designed, (c) is engineered for reliability, and (d) provides a much simpler system and method for accurately setting the headspace in the firing chamber when the rifle is converted for firing ammunition of a different caliber. 
     In one aspect, there is provided a rifle apparatus for firing a plurality of different calibers of ammunition. The rifle apparatus preferably comprises: (a) a receiver body having a barrel attachment nose projecting from a forward end of the receiver body, wherein the barrel attachment nose has exterior threads thereon; (b) a replaceable rifle barrel for firing at least a selected one of the plurality of different calibers of ammunition, the replaceable rifle barrel having a rearward end portion and a threaded portion forwardly of the rearward end portion, wherein the rearward end portion of the replaceable rifle barrel is receivable in the barrel attachment nose of the receiver body and the threaded portion of the replaceable barrel has exterior threads thereon; (c) a barrel attachment collar positioned around the replaceable rifle barrel, wherein the barrel attachment collar has a threaded portion with interior threads sized for threaded attachment to the exterior threads of the barrel attachment nose and the barrel attachment collar also has an inwardly extending retention shoulder positioned forwardly of the threaded portion of the barrel attachment collar; and (d) a barrel adjustment nut having interior threads and an outwardly extending retention shoulder, wherein the barrel adjustment nut is threadedly received on the threaded portion of the replaceable rifle barrel and the outwardly extending retention shoulder of the barrel adjustment nut is configured and is positioned within the barrel attachment collar for abutting a rearward surface of the inwardly extending retention shoulder of the barrel attachment collar. 
     In another aspect, there is provided a method using the rifle apparatus described above for installing the replaceable rifle barrel. The method preferably comprises the steps of: (a) inserting the rearward end portion of the replaceable rifle barrel into the barrel attachment nose of the receiver body and then (b) threadedly tightening the barrel attachment collar onto the exterior threads of the barrel attachment nose of the receiver body. 
     In another aspect, the method can further include the steps, after step (a), of: (i) placing a headspace gauge in a rifle chamber of the rifle apparatus and then (ii) turning the barrel adjustment nut to increase or decrease a headspace in the rifle chamber to correspond to the headspace gauge. 
     In another aspect, the rifle apparatus can include a barrel jam nut which is threadedly received on the threaded portion of the replaceable rifle barrel forwardly of the barrel adjustment nut. 
     In another aspect, where the rifle apparatus further comprises a barrel jam nut which is threadedly received on the threaded portion of the replaceable rifle barrel forwardly of the barrel adjustment nut, the method can also include the step, after step (ii), of tightening the barrel jam nut against the barrel adjustment nut to lock the barrel adjustment nut in place. 
     In another aspect, the rifle apparatus can include a replaceable lower receiver attachable to the bottom of the receiver body, the replaceable lower receiver having a well opening provided therethrough for receiving a magazine for loading the selected one caliber of ammunition fired by the replaceable rifle barrel. 
     In another aspect, the rifle apparatus can include a magazine lock lever pivotably mounted in the replaceable lower receiver and configured and positioned to contact the magazine clip received in the well opening of the replaceable lower receiver and to lock the magazine in place in the well opening. 
     In another aspect, the rifle apparatus can include a tension spring retained in the replaceable lower receiver in operative contact with the magazine lock lever to bias the magazine lock lever toward a locking engagement with the magazine clip. 
     In another aspect, the rifle apparatus can include a finger-operable release lever installed in the replaceable lower receiver for pivoting the magazine lock lever to an unlocked position to release the magazine clip from the magwell opening. 
     In another aspect, there is provided a rifle apparatus for firing a plurality of different calibers of ammunition comprising: (a) a receiver body; (b) a replaceable barrel which is removably attachable to the receiver body for firing at least a selected one of the plurality of different calibers of ammunition; and (c) a replaceable lower receiver attachable to the bottom of the receiver body, the replaceable lower receiver having a well opening provided therethrough for receiving a magazine clip for loading the selected one caliber of ammunition fired by the replaceable barrel. 
     Further aspects, features and advantages of the present invention will be apparent to those of ordinary skill in the art upon examining the accompanying drawings and upon reading the following Detailed Description of the Preferred Embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a right side perspective view of an embodiment  2  of the inventive rifle apparatus. 
         FIG. 2  is a left side perspective view of the inventive rifle  2 . 
         FIG. 3  is an exploded view of the inventive rifle  2 . 
         FIG. 4  is an elevational side view of an embodiment  4  of a quick-change barrel assembly used in the inventive rifle  2 . 
         FIG. 5  is a cutaway, sectional, elevational side view of the quick-change barrel assembly  4 . 
         FIG. 6  is an elevational side view of a receiver  6  used in the inventive rifle apparatus  2 . 
         FIG. 7  is a perspective forward end view of the receiver  6 . 
         FIG. 8  is a perspective rearward end view of the receiver  6 . 
         FIG. 9  is a perspective view of a top cover charging assembly  8  used in the inventive rifle apparatus  2 . 
         FIG. 10  is a cutaway elevational side view of the top cover charging assembly  8 . 
         FIG. 11  is a perspective view of a quick-mount front gas block  70  used in the inventive rifle apparatus  2 . 
         FIG. 12  is an elevational rearward view of the quick-mount front gas block  70 . 
         FIG. 13  is an elevational side view of the quick-mount front gas block  70 . 
         FIG. 14  is a perspective view of a gas tube rear mounting block  76  used in the inventive rifle apparatus  2 . 
         FIG. 15  is an elevational forward view of the gas tube rear mounting block  76 . 
         FIG. 16  is an elevational side view of an upper hand guard/gas tube  75  used in the inventive rifle apparatus  2 . 
         FIG. 17  is a top plan view of the upper hand guard/gas tube  75 . 
         FIG. 18  is an elevational forward end view of the upper hand guard/gas tube  75 . 
         FIG. 19  is an elevational rearward end view of the upper hand guard/gas tube  75 . 
         FIG. 20  is an elevational side view of a lower hand guard  82  used in the inventive rifle apparatus  2 . 
         FIG. 21  is a top plan view of the lower hand guard  82 . 
         FIG. 22  is an elevational forward end view of the lower hand guard  82 . 
         FIG. 23  is an elevational side view of a replaceable lower receiver  10  and integrated magazine retention and ambidextrous release system  12  used in the inventive rifle  2 . 
         FIG. 24  is a top plan view of the lower receiver  10  and integrated magazine retention and ambidextrous release system  12 . 
         FIG. 25  is a cutaway elevational side view of the lower receiver  10  and integrated magazine retention and ambidextrous release system  12 . 
         FIG. 26  is a perspective view of the lower receiver  10  and integrated magazine retention and ambidextrous release system  12 . 
         FIG. 27  is a perspective view of a magazine lock and release lever  92  used in the integrated magazine retention and ambidextrous release system  12 . 
         FIG. 28  is a perspective view of a pivot pin  94  used in the integrated magazine retention and ambidextrous release system  12 . 
         FIG. 29  is a perspective view of a tension spring  96  used in the integrated magazine retention and ambidextrous release system  12 . 
         FIG. 30  is a perspective view of a finger-operated release lever  98  used in the integrated magazine retention and ambidextrous release system  12 . 
         FIG. 31  is an elevational side view of an alternative replaceable lower receiver  102  for the inventive rifle apparatus  2 . 
         FIG. 32  is a top view of the alternative lower receiver  102 . 
         FIG. 33  is a cutaway view of the replaceable lower receiver  102  as seen from perspective B-B shown in  FIG. 31 . 
         FIG. 34  is an enlarged view of section A of the lower receiver  102  shown in  FIG. 32 . 
         FIG. 35  is a perspective view of a finger-operatable left side release lever  106  used in the lower receiver  102 . 
         FIG. 36  is a perspective view of a magazine lock and release lever  108  used in the integrated magazine retention and ambidextrous release system of the lower receiver  102 . 
         FIG. 37  is a perspective view of a pivot pin  110  used in the integrated magazine retention and ambidextrous release system of the lower receiver  102 . 
         FIG. 38  is a perspective view of a tension spring  112  used in the integrated magazine retention and ambidextrous release system of the lower receiver  102 . 
         FIG. 39  is a perspective view of a magazine release extension screw  105  used in the integrated magazine retention and ambidextrous release system of the lower receiver  102 . 
         FIG. 40  is a perspective view of a finger-operatable right side tactical release tab  104  used in the integrated magazine retention and ambidextrous release system of the lower receiver  102 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment  2  of the inventive rifle apparatus is illustrated in  FIGS. 1-30 . The inventive rifle  2  preferably comprises: a quick-change barrel assembly  4 ; a threaded receiver  6  for the quick-change barrel assembly  4 ; a top cover charging assembly  8 ; a lower receiver and trigger guard assembly  10  which includes an integrated magazine retention and release system  12 ; a forward hand guard assembly  14  with an integrated gas tube assembly  16 ; a pistol grip  18  attached to the lower receiver  10 ; and a buttstock  20  removably attached to the threaded receiver  6 . 
     The quick-change barrel assembly  4  used in the inventive rifle apparatus  2  can be sized for firing ammunition of generally any one of a number of possible calibers including, but not limited to, 7.62×39, 233, 5.56×45, 300 Blackout, 6.8 spc, and 6.5 Grendel. Moreover, to convert the inventive rifle  2  to the use of a different caliber of ammunition, the barrel assembly  4  and the lower magwell  10  are simply replaced with an otherwise identical barrel assembly  4  and magwell  10  of the appropriate size and barrel length for the new ammunition. 
     In contrast to prior systems, the inventive quick-change barrel assembly  4  also provides simple and quick adaptation and fine adjustment of the headspace within the rifle chamber for the new caliber of ammunition selected. The term “headspace” refers to the distance within the chamber of a rifle from the face of the rifle bolt or breech to the forward part or feature of the chamber which engages the cartridge to prevent the cartridge casing from moving further forward in the chamber. 
     The quick-change barrel assembly  4  of the inventive rifle  2  is an inventive threaded adjustable barrel system which preferably comprises a rifle barrel  22  having: (a) an enlarged rearward end portion  24  which is insertable into a forward nose  26  of the threaded receiver  6 , (b) a rifle chamber  47  within the enlarged rearward end  24 , (c) an extractor cutaway  53  in the rearward end of the barrel  22 , (d) a longitudinal barrel alignment slot  53  in the enlarged rearward end  24 , and (e) a threaded portion  28  which is adjacent to and forward of the rearward end portion  24 , the threaded portion  28  having exterior threads  30 . In addition, the inventive quick-change barrel assembly  4  preferably further comprises: (a) a barrel attachment collar  32 ; (b) a barrel adjustment nut  38  having internal threads  34 ; and (c) a barrel jam nut  48 . 
     The barrel attachment collar  32  is positioned around the rearward portion  24  and/or the threaded portion  28  of the rifle barrel  22 . The barrel attachment collar  32  has internal threads  34  and a forward retention shoulder  36  which projects radially inward toward the rifle barrel  22 . When the enlarged rearward end portion  24  of the rifle barrel  22  is inserted into the forward nose  26  of the threaded receiver  6 , the barrel attachment collar  32  is threadedly receivable over and threadedly attachable to the threaded exterior  33  of the receiver nose  26 . 
     The barrel adjustment nut  38  is threadedly received on the threaded portion  28  of the rifle barrel  22  and has a rearward retention shoulder  42  which is positioned within the barrel attachment collar  32  and projects radially outward to engage the rearward surface  44  of the inner retention shoulder  36  of the collar  32 . 
     The barrel jam nut  48  is threadedly received on the threaded portion  28  of the rifle barrel  22  and is positioned forwardly of and against the forward end of the barrel adjustment nut  38 . The barrel jam nut  48  is used to lock the other components of the assembly in position to set the necessary headspace in the rifle chamber  45  for the caliber of ammunition selected. 
     Whenever any embodiment of the inventive quick-change barrel assembly  4 , sized for a certain caliber of ammunition, has been previously set for use in the inventive rifle apparatus  2  to provide the proper headspace for the ammunition in the rifle chamber, the previously used barrel assembly  4  can be quickly reinstalled on the rifle  2  by (a) inserting the rearward end  24  of the rifle barrel  22  into the forward nose  26  of the threaded receiver  6  and then (b) threadedly tightening the barrel attachment collar  32  onto the threaded exterior  33  of the receiver nose  26 . Similarly, any quick-change barrel assembly  4  can be easily removed from the rifle  2  by (a) loosening the barrel attachment collar  32  such that it is completely detached from the externally threaded forward nose  26  of the receiver  6  and (b) sliding the rearward end  24  of the rifle barrel  22  out of the receiver nose  26 . 
     However, if the inventive quick-change barrel assembly  4  is a new assembly  4  (e.g., for a different caliber of ammunition) which has not been previously set for use on the rifle  2 , the quick-change barrel assembly  4  can be easily adjusted and set to provide the proper headspace for the ammunition in the rifle chamber by: (1) loosening the barrel jam nut  48 ; (2) inserting the rearward end  24  of the rifle barrel  22  into the forward nose  26  of the threaded receiver  6 ; (3) placing a headspace gauge in the rifle chamber  47 ; (4) turning the barrel adjustment nut  38  to increase or decrease the chamber headspace to correspond to the headspace gauge; (5) tightening the barrel jam nut  48  to lock the barrel adjustment nut  38  in place; and (6) threadedly tightening the barrel attachment collar  32  onto the threaded exterior  33  of the receiver nose  26 . 
     In contrast, to install a barrel on a standard AK 47, for example, a fixture and barrel press must be used for applying approximately 10 tons of pressure. Also, upon establishing the proper headspace, a hole must be machined through the front trunnion of the AK 47 receiver. A 7 mm barrel retaining pin must then be press fit to hold the barrel in place. Similarly, to remove the barrel from the AK 47, the retaining pin must be pressed out, the receiver and barrel assembly must be installed in the fixture and barrel press, and the barrel must be pressed out. 
     As noted above, the threaded barrel attachment nose  26  of the inventive rifle apparatus  2  projects from the forward end of the threaded receiver  6 . The rearward end of the threaded receiver  6  preferably includes an internally threaded port  50  for removably receiving the buttstock  20  and is also preferably configured in the manner shown in  FIGS. 6 and 8  for accepting an AR-style buffer tube mount system. 
     The top cover charging assembly  8  of the inventive rifle apparatus preferably comprises: (a) a top cover  52  with an upper Picatinny rail  54 ; (b) a charging handle  56  which is slideably received in the rearward end of the top cover  52  and comprises a rod  58  having a gripping handle  60  on the outer end thereof; and (c) a carrier and gas tube assembly  64  which is positioned within the top cover  52 . 
     As seen in  FIGS. 3, 9, and 10 , the carrier and gas tube assembly  64  comprises: a carrier  65  which is reciprocatably mounted in a slide  62  in the top of the threaded receiver  6  for operation of the rifle firing chamber, an elongate gas tube  66  which is slideably received in the forward end of the carrier  65  for reciprocating movement of the carrier  65  on the tube  66  to provide fully automatic or semi-automatic operation of the inventive rifle apparatus  2 ; and a carrier boss  68  provided on the top of the carrier  65  which is slidably received in a groove  69  in the bottom of the rod  58  of the charging handle  56  for engagement by the charging handle  56  when the charging handle  56  is pulled rearwardly for chambering a round. 
     The forward hand guard assembly  14  of the inventive rifle apparatus  2 , and the gas tube assembly  16  which is integrated therewith, preferably include a quick-mount front gas block  70  which has a bottom clamp portion  71  that is secured (e.g., using clamping bolts or screws) on the rifle barrel  22  over a small gas port (not shown) provided in the top of the barrel  22 . The quick-mount front gas block  70  also has an upper gas discharge port  73  that receives the forward end  72  (i.e., the gas inlet end) of the gas tube  66 . 
     In addition, the forward hand guard assembly  14  and integrated gas tube assembly  16  preferably also include: (a) an upper hand guard  75 , with a top Picatinny rail  74 , which is positioned over the barrel  22 , and in which the gas tube  66  and the front gas block  70  are received; (b) a gas tube rear mounting block  76  with an inverted U shape which is positioned over the carrier  65 ; and (c) a lower hand guard  82 , with cross-sectional U shape and a bottom Picatinny rail  84 , which is positioned beneath the rifle barrel  22  and includes a rearwardly projecting bottom bracket  86  which is attached by bolts or screws to the bottom of the receiver  6 . The upper hand guard  75  and the lower hand guard  82  are also removably attached together using bolts or screws. 
     The gas tube rear mounting block  76  has a pair of outwardly projecting side flanges  89  and  91  on the bottom thereof which are removably receivable in an opposing pair of grooves  93  and  95  of an attachment slot  97  provided on the top of the receiver  6  at the forward end thereof. With the rear mounting block  76  in place in the attachment slot  97 , the top cover  52  can be removably secured to the top of the rear mounting block  76  using a bolt or screw  77 . 
     The lower receiver and trigger guard body  10  is attached to the bottom of the receiver body  6  and, as noted above, includes an integrated magazine retention and ambidextrous release system  12 . The lower receiver  10  and integrated magazine retention and release system  12  include a well opening  88  for receiving a magazine clip  90  for loading ammunition of a selected caliber as discussed above 
     The lower receiver  10  and integrated magazine retention and release system  12  further comprise: a magazine lock and release lever  92  which is pivotably mounted at the rearward end of the well opening  88 ; a pivot pin  94  on which the lever  92  is pivotably mounted in the lower receiver  10 ; a tension spring  96  mounted in the lower receiver  10  for biasing the pivotable lock/release lever  92  into locking engagement with the magazine clip  90 ; an index finger-operatable release  98  which extends laterally through the lower portion of the magazine lock, the release lever  98  having a pushable button  99  on each side of the lower receiver  10  which can be pushed using either hand to thereby pivot the lock and release lever  92  out of locking position for releasing the magazine clip  90 ; and an anti-rattle spring  100  for reducing or eliminating the rattle of the magazine  90 . 
     An alternative embodiment  102  of the replaceable lower receiver for the inventive rifle  2  is illustrated in  FIGS. 31-40 . Rather than utilizing the ambidextrous magazine release system  12  described above, the lower receiver  102  uses an alternative ambidextrous integrated magazine retention system which comprises (a) a pivotable, finger-operatable, exterior tactical right side release tab  104  which rotates an internal magazine release extension screw  105  for releasing the magazine clip  90  and (b) a pivotable, finger-operatable left side release lever  106  which also interacts with the opposite end of the release extension screw  105  for releasing the magazine clip  90 . 
     In addition, similar to the magazine retention and release system  12 , the magazine retention and release system of the lower receiver  102  further comprises: a magazine lock and release lever  108 ; a pivot pin  110  for the lever  108 ; and a tensioning spring  112 . 
     Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within this invention as defined by the claims.