Abstract:
A flex-plate adapter for a takedown firearm has front and rear sections. The rear section includes adjustment screws to change the gap between the front and rear sections. Guide pins are included for assuring proper alignment between the front and rear sections. The adjustable gap between the front and rear sections of the flex-plate adapter provides compensation for thread wear. A magazine cutoff provides a manual cutoff for retaining ammunition in the magazine whether the rifle is assembled or disassembled. A cutoff lock prevents the accidental movement of the magazine cutoff.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to firearms and particularly relates to takedown firearms. 
     2. Description of the Prior Art 
     Takedown lever-action rifles are a type of lever-action rifle that is particularly popular. The term “takedown rifle” describes a rifle in which the barrel and fore-end are readily connected with and detached from the buttstock and receiver frame so as to permit the rifle to be more easily packed and compactly transported. 
     During World War II, the Japanese developed a takedown rifle for issue to airborne units. A standard bolt-action rifle was modified to accommodate a special barrel with interrupted threads at its chamber end that mated with threads on a sleeve provided at the front end of the receiver. This rifle proved to be unsuccessful. Thereafter, another version was developed which featured a barrel locked in place by means of a tapered wedge but its accuracy at best was mediocre. 
     Rifles utilizing a takedown feature are shown in U.S. Pat. Nos. 529,455; 534,691; 605,111; 605,734; 616,719; 755,660; 855,181; 1,065,341 and 1,370,836. In spite of numerous developments in the art of takedown rifles, virtually all such rifles suffer from the inability to “hold zero,” or repeat the point-of-aim after the barrel has been repeatedly removed and reinstalled. Lever-action rifles, in particular, suffer because they are used for hunting and are frequently disassembled. This disassembly/assembly operation puts stress on the threads in the barrels and receivers, causing the barreled fore-end and front sight to be misaligned with the receiver and rear sight when completely assembled. 
     Deviation is not acceptable for long range precision shooting such as may be required for target use or sniper use by the military and law enforcement organizations. In order to obtain the degree of accuracy considered acceptable for sniper or target shooting, all components of any rifle, and particularly a takedown rifle, must fit together in an extremely tight manner with very close tolerances. Without the means to compensate for wear, particularly wear of the threads in mating parts, any rifle that is repeatedly disassembled and reassembled will lose its accuracy, resulting in a change in the point of impact of the bullet. 
     The ammunition magazine for lever-action rifles is typically located beneath, and attached to, the barrel. Generally, ammunition in the magazine of a takedown rifle is retained in the magazine only while the rifle is completely assembled. There is no provision for retaining ammunition therein while disassembled. Thus, when the rifle is reassembled, ammunition must be loaded into the magazine through the rifle&#39;s receiver. 
     Consequently, there is a need to provide a takedown lever-action firearm that can be repeatedly disassembled and reassembled with provision for maintaining its accuracy. There is also a need for retaining ammunition in the magazine while the weapon is disassembled to provide ready and immediate access when reassembled. 
     SUMMARY OF THE INVENTION 
     It is therefore one object of the present invention to provide a method and apparatus that will allow for easy assembly and disassembly of the barrel to the receiver and effectively compensate for wear in the threaded connection that mates the barrel to the rifle. 
     It is another object of the present invention to provide an apparatus for retaining ammunition in the magazine of the rifle when disassembled. 
     A flex-plate adapter for a takedown firearm is provided which has front and rear sections. The rear section includes adjustment screws to change the gap between the front and rear sections. Guide pins are included for assuring proper alignment between the front and rear sections. The adjustable gap between the front and rear sections of the flex-plate adapter provides compensation for thread wear. A magazine cutoff provides a manual cutoff for retaining ammunition in the magazine whether the rifle is assembled or disassembled. A cutoff lock prevents the accidental movement of the magazine cutoff. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed to be characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a side elevational view of a prior art takedown firearm; 
     FIG. 2 is a an exploded view of the prior art takedown rifle of FIG. 1 illustrating the means for connecting the barrel and the receiver; 
     FIG. 3 is an enlarged rear view of a flex-plate adapter for adjusting alignment of a takedown firearm barrel and retaining ammunition in the magazine in accordance with a preferred embodiment of the present invention; 
     FIG. 4 is a side elevational view of the adapter of FIG.  3 . 
     FIG. 5 is a an exploded side elevational view of a takedown firearm having an adapter in accordance with FIG. 3; and 
     FIG. 6 is a view of the flex-plate adapter of FIG. 3 partially assembled with the firearm of FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference now to the figures, and in particular with reference to FIG. 1, a takedown firearm  100  is illustrated. Firearm  100  is, in this case, a lever-action rifle. Buttstock  102  is generally constructed of non-metal material and is placed against a shooter&#39;s shoulder for shooting. Lever  104  is part of a mechanism which cocks the hammer of the rifle, ejects a spent ammunition case, and chambers a live round of ammunition for firing. Trigger guard  106  prevents an accidental trigger pull. Fore-end  108  is used for holding the rifle. Magazine  110  is removably attached to barrel  112  and is used for storing a horizontal column of ammunition which is spring-biased toward the receiver. The live round is inserted into the firing chamber utilizing lever  104  mechanism prior to firing. The spent cartridge is ejected from ejection slot  116  when lever  104  is actuated to load a live ammunition round into receiver  114 . 
     The lever-action rifle illustrated is a takedown rifle showing the connecting mechanism between the barrel and the receiver in FIG.  2 . Generally, a takedown rifle utilizes a threaded extension of the barrel to positively connect to the receiver. Barrel connector  118 , a threaded portion of barrel  112 , is used to connect to receiver  114 . This feature of easy assembly, by threading barrel  112  to receiver  114 , allows for easy carrying and storage of rifle  100 . However, because of the frequency of use of the takedown feature, the threads become worn over time and the alignment of barrel  112  and receiver  114  changes. 
     Referring to FIGS. 3 and 4, a detailed view of a flex-plate adapter for adjusting alignment of a takedown firearm barrel and retaining ammunition in the magazine in accordance with a preferred embodiment of the present invention is illustrated in a rear view (FIG. 3) and a side view (FIG.  4 ). Flex-plate adapter  200  comprises two sections: adjustment section  202  and receiver section  203 . Barrel opening  204  and magazine opening  206  are cylindrical and extend through both sections  202 ,  203 . The portion of opening  204  in section  203  is shown as having threads  205 , though section  203  may be attached to barrel connector  118  by other means such as, for example, soldering. The front surface of section  203  has a recess  207  shaped for receiving fore-end  108 . Though not shown in the figures, magazine opening  206  may have a relief cutout in the forward area when used in larger caliber rifles, the cutout providing sufficient clearance to allow larger cartridges to be loaded into magazine  110 . 
     Guide pins  209  protrude from the front surface of adjustment section  202 . When assembled, guide pins  209  are inserted into receiving sockets  211  in receiver section  203 . Allen screws  208 ,  210  connect the sections and adjust the distance from the front surface of section  202  to the rear surface of section  203 . As allen screws  208 ,  210  are turned, the longitudinal length of adapter  200  changes. Allen screws  208 ,  210  are adjusted until the length of adapter  200  is such that, when assembled, barrel  112  is tightly fitted to receiver  114 . Screws  208 ,  210  also may be adjusted individually to alter the planar orientation of sections  202 ,  203  to each other for adjusting the point-of-impact of a bullet fired from barrel  112 . Only slight changes in the planar orientation are required to adjust the vertical or horizontal position of the forward end of barrel  112  (FIG. 1) relative to receiver  114  (FIG.  1 ). Guide pins  209  deflect a small amount if the planar orientation is other than parallel. 
     Magazine cutoff  212  is used for retaining ammunition within magazine  110  by partially blocking opening  206 . Cutoff  212  is a cylindrical pin extending transversely through section  203  and is shown fully extended in the closed position which prevents ammunition from exiting magazine  110  (FIG.  1 ). Screw  213  engages a translating slot  214  in cutoff  212  for retaining and limiting the travel of cutoff  212  within section  203 . Screw  213  preferably has a spring-biased plunger for engaging detents (not shown) in slot  214  as cutoff  212  is moved into the open and closed positions. 
     When cutoff  212  is moved to the open position, a cutout  215  aligns with the bottom of opening  206 , permitting ammunition stored in magazine  110  to feed into receiver  114 . When disassembling the rifle, cutoff  212  is pushed to the closed position to move cutout  215  out of alignment with opening  206 , preventing ammunition from exiting magazine  110 . Cutoff lock  216  is located above cutoff  212  in section  203  and prevents accidental cutoff of ammunition. Lock  216  comprises a vertical plate within section  203  and an attached head external to section  203 . Lock  216  is spring-biased in a downward direction by spring  218 , and a lower portion of the vertical plate of lock  216  engages notch  220  in cutoff  212  when cutoff  212  is moved to the open position. To move cutoff  212  to the closed position, lock  216  is pulled upward as cutoff  212  is simultaneously moved to the closed position. Though shown in the figures as a sliding type, cutoff  212  may also be rotary. 
     Referring now to FIGS. 5 and 6, flex-plate adapter  200  is shown partially assembled to the fore-end portion  113  of a takedown rifle. Barrel connector  118 , a threaded portion of barrel  112 , is shown inserted into opening  204  of adapter  200 . Threads  205  of receiver section  203  engage threads on barrel connector  118 . Allen screws  208 ,  210  are shown in an extended position, illustrating the adjustment feature of adapter  200 . Gap  302  is a result of the adjustment of alien screws  208 ,  210 . Guide pins  209  are inserted into sockets  211  for maintaining the alignment of adjustment portion  202  with receiver portion  203  of flex plate  200 . 
     Flex-plate adapter  200  is properly fitted and adjusted prior to affixing section  203  to the barrel/fore-end portion  113  of the takedown rifle. Receiver section  203  of flex-plate adapter  200  abuts fore-end  108  and receives barrel  112 . To install the combination of flex-plate adapter  200  and fore-end  113 , barrel connector  118  is threaded into receiver  114  until adjustment section  202  abuts receiver  114  and the connection is completely tightened. Necessary adjustments in gap  302  are made by removing fore-end  113  and adapter  200  and adjusting allen screws  208 ,  210  until proper alignment of fore-end  113  to receiver  114  is achieved when the rifle is reassembled. Compensation for any change in travel of barrel connector  118  is made by adjusting gap  302  of flex-plate adapter  200 , thus increasing or decreasing the travel distance of the threads of barrel connector  118  into receiver  114 . To allow ammunition to feed in to receiver  114 , cutoff  212  is moved from the closed position to the open position until lock  216  engages notch  220 . To prevent ammunition from feeding, cutoff lock  216  is moved upward to disengage lock  216  from notch  220 , and cutoff  212  is moved to the closed position. 
     The adapter of the present invention has the advantage of providing a means of compensating for thread wear in the connection between the fore-end and receiver of a takedown firearm. By having multiple screws connecting the front and rear sections of the adapter, an additional advantage is that the point-of-impact can be adjusted vertically and horizontally. Also, the magazine cutoff allows for ammunition to be retained in the magazine when the rifle is disassembled. The cutoff lock prevents accidental cutoff of the magazine. 
     While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.