Patent Publication Number: US-10788276-B2

Title: Rifle to fire pistol cartridges

Description:
FIELD OF THE INVENTION 
     The present invention relates to a semi-automatic, select fire, and/or fully automatic rifle platform capable of shooting a pistol cartridge. This original rifle equipment includes a straight, perpendicularly mounted magazine, an ejector in the upper receiver, a feed ramp in the lower receiver and an integral bolt, which encapsulates the cartridge in the chamber. 
     BACKGROUND OF THE INVENTION 
     Rifles having firing options, including those heretofore known as semi-automatic, select fire (such as three shot burst), and fully automatic, are well known in the art. These semi-automatic, select fire, and/or fully automatic guns are commonly used by military personnel, law enforcement, competitive shooters, and gun enthusiasts. 
     To become proficient, a great deal of practice and training are required. The cost of the high caliber ammunition becomes an economic consideration for the users of such guns. Therefore, conversion kits have become available to convert the AR15, or similar weapons, to use smaller caliber cartridges, such as the 9 mm and 45 ACP used in pistols and handguns, which are more cost efficient. However, such conversion kits require the rifle to be partially disassembled with replacement parts being substituted for original parts. The conversion kit then must be removed and the original equipment reassembled before the rifle can be used with high caliber cartridges as designed. 
     There are several different styles of conversion kits, varying from metal inserts that go into the magazine well of the lower receiver, to all new lower receivers that use conventional hand gun magazines. These conversion kits have several issues. 
     First, they use currently commercial available magazines which have an angle that feeds the cartridge up the magazine to the chamber, which creates a tendency to jam due to the feed angle. Also, the inclined feed angle of the magazine requires a greater spring force to push or feed the cartridges into the chamber in front of the bolt as compared to a perpendicular feed angle. Extended cartridge pistol magazines tend to jam when trying to feed the cartridges into a rifle. The more cartridges that go into a magazine, the less reliable the magazine is. Furthermore, the pistol magazines used in the conversion kits generally are not as durable and can be easily damaged, which further impedes functionality of the rifle firing system. 
     Secondly, when the rifle bolt carrier is released from the charging position, there often is bolt bounce or bolt slap. As the weight of the carrier picks up a cartridge from the magazine and places the cartridge in the chamber, the carrier slaps the bolt face and bounces back, while still having the live cartridge in the bolt face being held by the extractor. If the trigger is pulled at the incorrect time, there is a possibility of an out of battery firing wherein the cartridge detonates outside of the chamber. Such an out of battery firing can rupture the case and cause bodily injury and may damage and/or destroy the firearm. 
     Therefore, there is a need for a semi-automatic, select fire, and/or fully automatic rifle platform which addresses the issues of the prior art. 
     Accordingly, a primary objective of the present invention is the provision of a semi-automatic, select fire, and/or fully automatic rifle which is designed and built to shoot pistol caliber cartridges, without utilizing a conversion kit. 
     A further objective of the present invention is the provision of an improved magazine for a semi-automatic, select fire, and/or fully automatic rifle which has a large capacity that feeds into the chamber of the upper receiver in a direction perpendicular to the chamber axis. 
     Another objective of the present invention is the provision of a semi-automatic, select fire, and/or fully automatic rifle having an integral bolt carrier which fully encloses the cartridge inside the chamber so as to preclude out of battery firing. 
     Another objective of the present invention is the provision of a semi-automatic, select fire, and/or fully automatic rifle having an ejection system in the upper receiver. 
     Still another objective of the present invention is the provision of a semi-automatic, select fire, and/or fully automatic rifle having a feed ramp in the lower receiver for the cartridge. 
     A further objective of the present invention is the provision of a semi-automatic, select fire, and/or fully automatic rifle having interchangeability of the majority of the parts commonly found on the M16A1 M16A2, the current M-4 carbine, and commercial variations. 
     Another objective of the present invention is the provision of a semi-automatic, select fire, and/or fully automatic rifle has reliability and has an extended service life. 
     These and other objectives will come apparent from the following description of the invention. 
     SUMMARY OF THE INVENTION 
     The semi-automatic, select fire, and/or fully automatic rifle has an upper receiver to accept an integral bolt and a lower receiver to accept a magazine. The magazine is designed to feed the cartridge straight into the chamber in the upper housing, in a path perpendicular to the chamber longitudinal axis. The bolt encloses the rear of the cartridge in the chamber to preclude out of battery firing. The lower receiver includes a feed ramp to direct the cartridge from the magazine into the chamber. The upper receiver has an ejector for discharging the cartridge from the bolt face then the upper receiver. The magazine includes a mechanism to lock the bolt after the last shot. The rifle is designed to shoot pistol or handgun caliber ammunition, without removing or exchanging components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of the semi-automatic, select fire and/or automatic rifle according to the present invention. 
         FIG. 2  is a sectional view along the longitudinal axis of the rifle. 
         FIG. 2A  is an enlarged view of  FIG. 2 . 
         FIG. 2B  is a sectional view similar to  FIG. 2A , but showing the chamber empty without a cartridge and the bolt locked back. 
         FIG. 2C  is a sectional view similar to  FIG. 2B  with the magazine follower extended to the bolt lock position after the last cartridge is fired. 
         FIGS. 3A-3E, 4A-4D, 5 and 6  show the bolt of the rifle, according to the present invention. 
         FIG. 3A  is a side elevation view of the bolt. 
         FIG. 3B  is a bottom plan view of the bolt. 
         FIG. 3C  is another side elevation view of the bolt from the side opposite that is shown in  FIG. 3A . 
         FIG. 3D  is a top plan view of the bolt. 
         FIG. 3E  is a view similar to  3 C, with the bolt rotated slightly about its longitudinal axis. 
         FIG. 4A  is a sectional view taken along line A-A of  FIG. 3A . 
         FIG. 4B  is a sectional view taken along line B-B of  FIG. 3B . 
         FIG. 4C  is a sectional view taken along lines C-C of  FIG. 3C . 
         FIG. 4D  is a sectional view taken along lines D-D of  FIG. 3D . 
         FIG. 5  is an elevation view from the forward end of the bolt. 
         FIG. 6  is an elevation view from the rear end of the bolt. 
         FIG. 7  is a perspective view of the upper receiver of the rifle. 
         FIGS. 7A and 7B  are side elevation views of the upper receiver, from opposite sides. 
         FIG. 7C  is a top plan view of the upper receiver. 
         FIG. 7D  is a bottom plan view of the upper receiver. 
         FIG. 7E  is an end elevation view of the upper receiver from the forward end. 
         FIG. 7F  is an end elevation view at 90° of the upper receiver from the rearward end. 
         FIG. 7G  is a sectional view of the upper receiver taken along lines  7 G of  FIG. 7B . 
         FIG. 7H  is a view similar to  FIG. 7G  showing the upper receiver, showing the ejector in the upper receiver. 
         FIG. 8  is a perspective view of the lower receiver. 
         FIG. 8A  is an elevation view from one side of the lower receiver. 
         FIG. 8B  is an elevation view from the opposite side of the lower receiver. 
         FIG. 8C  is a top plan view of the lower receiver. 
         FIG. 8D  is a bottom plan view of the lower receiver. 
         FIG. 8E  is an elevation view from the rear end of the lower receiver. 
         FIG. 8F  is an elevation view from the front end of the lower receiver. 
         FIG. 8G  is a sectional view of the lower receiver taken along lines  8 G- 8 G of  FIG. 8D . 
         FIG. 9  is a perspective view of the extension of the rifle. 
         FIG. 9A  is a top elevation view of the extension. 
         FIG. 9B  is an elevation view of the extension from the forward end. 
         FIG. 9C  is another elevation view of the extension from the rearward end. 
         FIG. 9D  is a sectional view taken along lines D-D of  FIG. 9A . 
         FIG. 10  is a perspective view of the feed ramp for the rifle. 
         FIGS. 10A and 10B  are opposite end elevation views of the feed ramp. 
         FIG. 10C  is a side elevation view of the feed ramp. 
         FIG. 10D  is a top plan view of the feed ramp. 
         FIG. 11  is a perspective view of the ejector for the rifle. 
         FIG. 11A  is a side elevation view of the ejector. 
         FIG. 11B  is another elevation view of the ejector, turned at 90° from  FIG. 11A . 
         FIG. 11C  is a bottom plan view of the ejector. 
         FIG. 11D  is a sectional view of the ejector taken along line D-D of  FIG. 11B . 
         FIG. 12  is a perspective view of the bolt charging handle guide. 
         FIG. 12A  is a side elevation view of the guide. 
         FIG. 12B  is a top plan view of the guide. 
         FIG. 12C  is an end elevation view of the guide. 
         FIG. 12D  is a sectional view of the guide taken along lines D-D of  FIG. 12C . 
         FIG. 13  is an exploded perspective view of the semi-automatic, select fire and/or automatic rifle according to the present invention. 
         FIG. 14  is a perspective view of the rifle magazine. 
         FIG. 15  is a longitudinal sectional view of the magazine. 
         FIG. 16  is an exploded view of the magazine. 
         FIG. 17  is a lateral sectional view of the magazine taken along line  17 - 17  of  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     A semi-automatic, select fire, and/or fully automatic rifle according to the present invention is generally designated in the drawings by the reference numeral  10 . The invention focuses on several key components of the rifle  10 , including the bolt  12 , the upper receiver  14 , the lower receiver  16 , and the magazine  18 . 
     The bolt  12  is shown in  FIGS. 3-6 . The bolt  12  has a one piece, integral construction. The bolt is slideably received within the upper receiver  14  for movement between a retracted rear position which allows the cartridge  20  to be fed into the chamber  22  in the upper receiver  14 , and a forward firing position. The forward end of the bolt  12  has a recess  17  which receives the rear end of the cartridge. When the bolt  12  is in the firing position, the forward end of the bolt fully encloses the rear of the cartridge  20 , as shown in  FIG. 2A . This complete enclosure of the cartridge  20  by the chamber and bolt precludes out of batter firing, and thus prevents damage to the rifle  10  and injury to the user and/or firearm. This integrated bolt and carrier  13  design allows the cartridge case to be secure inside the chamber before the rifle can be fired. Also, the hand over hand type bolt and chamber design will not permit case rupture, even in the event of bolt slap (which is normally eliminated by the bolt  12 ). The solid, one piece bolt carrier  12 ,  13  eliminates the need to disassemble multiple parts for cleaning, as in the prior art, and increases bolt mass for the blow back system. 
     An extension  26  is mounted on the forward end of the upper receiver  14 . The extension is shown in  FIGS. 9-9D . The extension  26  threads onto the barrel  34  which slides into the forward end of the upper receiver  14 . The extension  26  also has an internal inclined ramp  32  which facilitates movement of the cartridge  20  into the barrel  34  of the rifle  10 . The reduced diameter portion  15  on the end of the bolt  12  pushes the cartridge  20  through the extension and into the barrel  34 , as seen in  FIG. 2A . This steel extension  26  provides a ring or band around the cartridge and chamber, and discourages or prevents use of non-compatible cartridges. 
     A feed ramp  36  is mounted on the lower receiver  16 , such as by roll pins driven down, extending through holes  38  on each side of the ramp  36 . The ramp  36  has an inclined surface  40  which aligns with the ramp  32  of the extension  26 , as best seen in  FIG. 2A , to provide a smooth feed of the cartridge  20  from the magazine  18 . 
     The upper receiver  14  includes an ejection system for ejecting the expended shell case from the rifle  10 . The ejection system includes an ejector  42  mounted in the upper receiver  14 , as compared to prior art ejectors which are spring mounted on the bolt face. A roll pin pins the ejector  42  to the upper receiver  14  via a hole in the head of the ejector as best seen in  FIG. 7H . 
     The upper receiver  14  and the lower receiver  16  are coupled by pins, as is known in the art. A pistol grip  46  is mounted on the lower receiver  16  in a conventional manner. A conventional trigger  48  is pinned to the lower receiver  16 , and a trigger guard  50  is pinned to the lower receiver  16  to prevent accidental actuation of the trigger  48 . Other conventional components of the lower receiver include the sear  52 , the safety latch  54 , the hammer  56 , the bolt stop  58 , and the magazine catch push button  60 . Components of the bolt  12  include the extractor  62 , and the firing pin  64 . An extractor  62  is mounted in a slot in the bolt  12 . 
     A conventional buffer tube  66  is threadably mounted to the collar  17  on the lower receiver  16 , with the butt stock  72  being mounted on the buffer tube, in known manners. A conventional buffer tube plate  68  is provided on the buffer tube  66 , is well known in the art. A buffer tube retaining nut  70  is on the rearward end of the upper receiver  14 . The butt stock lock latch  74  is also provided on the butt stock  72 , as is known in the art. 
     A bolt guide  76  ( FIG. 12 ) is provided on the bolt  12 . A standard charging handle  78  is provided to move the bolt between the forward and rearward positions for loading a round. 
     A conventional free float tube  80  surrounds the barrel  34 . A muzzle device  82  is threadably mounted on the front end of the barrel  34 . 
     The magazine  18  is removably inserted into the lower receiver  16  and retained by the catch  60 . The magazine  18  is adapted to hold a plurality of cartridges  20  of the desired small caliber, such a 9 mm and/or 45 ACP. A follower  84  slidably mounts within the magazine shell. The cartridges  20  are pushed into the chamber, in a direction perpendicular to the chamber axis, by the follower  84  via upward force by the spring  90  in the magazine  18 . The perpendicular feed direction reduces the spring force, as compared to prior art inclined magazine feeds. The follower includes a unique rib  86  which is received in a groove  88  in the magazine. The rib  86  and groove  88  design allow for the bolt hold open to actuate the bolt stop, which allows the bolt to stop open upon the firing of the last cartridge from the magazine. This will indicate to the user that the magazine  18  is empty and a new magazine needs to be loaded into the lower receiver  16  of the rifle  10 . The rib  86  keeps dirt and other contaminants out of the magazine  18 . Also, in low light or dark environments, the rear magazine groove  88  provides a tactile feel to the user so as to properly orient the magazine  18  for loading into the lower receiver  16 . 
     When the last cartridge is shot from the rifle  10 , the follower  84  extends upwardly. Thus, the bolt automatically locks after the last cartridge is fired, contrary to the prior art wherein the bolt did not lock after the last shot. 
     The rifle  10  is a complete rifle, and operates in a manner similar to a conventional AR15 shooting a .223 or 5.56×45 mm round, except that the rifle  10  shoots a pistol round. No disassembly or substitution of parts is required. 
     From the foregoing, it can be seen that the present invention accomplishes at least all of the stated of objectives.