Patent Abstract:
In an autoloading gun construction having the breach end of a barrel removably assembled to the forward end of a barrel extension which is positioned between and secured to wall sections of two opposing receiver plates of a receiver section, the improvement comprising an aperture formed thru each wall section, and a weld formed between edge portions of each aperture and adjacent portions of the barrel extension.

Full Description:
BACKGROUND OF THE INVENTION 
   1. Field 
   This invention relates in general to repeating firearms, and relates in particular to autoloading shotguns and other such firearms. 
   2. Prior Art 
   Past efforts to design improved, practical autoloading shotguns generally having been constrained by the effects of firing recoil, or by inadequately considering the effects of recoil when designing the gun. The term “autoloading” is herein used to denote a gun which, when fired, automatically ejects the spent shell and loads a fresh round from a magazine, and includes semi-automatic as well as full-automatic firing modes. 
   Although recoil affects any firearm to some degree, the relatively heavy recoil of shotguns is recognized by most shooters. Particularly in larger-gauge shotguns, recoil and percussion can loosen mechanical joints, i.e., riveted, screwed or bolted joints as shown in U.S. Pat. No. 4,693,170, the disclosure of which is hereby incorporated herein by reference, in its entirety. Fatigue of adjacent metal structures also is experienced. 
   Where dimensionally critical portions of the gun are involved, such as the breech area including the mechanical connection of the barrel to the barrel extension for guns which have a removable barrel, such loosening of joints can compromise smooth action of the autoloading mechanism as well as creating dangerous conditions of misfirings, premature firings, shell jamming and the like. 
   SUMMARY OF THE INVENTION 
   An autoloading gun construction having barrel extension means constructed for rapidly receiving cartridges, missile end first, and guiding them into the breach end of a barrel, wherein said extension means is positioned between and secured to wall sections of two opposing receiver plates of a receiver section by welding. 
   In a much preferred embodiment, quick disconnect means are provided on the extension means and barrel for quickly removing the barrel for renewal or replacement with a barrel of a different type. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be further understood from the drawings herein wherein certain structural portions are shown enlarged or out or proportion for clarity and where the same numbering of structures as in U.S. Pat. No. 4,693,170 is used for equivalent structure of the present invention: 
       FIG. 1  is a partially longitudinally cross-sectioned side view of the present barrel extension which is similar in some respects to the barrel extension  120  of the aforesaid U.S. Pat. No. 4,693,170; 
       FIG. 2  is a cross-sectional view taken along line  2 — 2  of  FIG. 1 ; 
       FIG. 3  is a cross-sectional view along line  3 — 3  in  FIG. 2  with structural portions broken away or removed for clarity; 
       FIG. 4  is a cross-sectional view taken along line  4 —∝in  FIG. 3  with portions broken away for clarity; 
       FIG. 5  is a side view as in  FIG. 1  with a portion of receiver side  117 R in place and welded to the edges of the locator land as indicated by the cross hatched outline, with portions of the weld broken away for clarity; 
       FIG. 6  is a view as in  FIG. 31  of said patent with original numbering retained and additional numbering added for the present modifications; and 
       FIG. 7  is a view as in  FIG. 4  but shown with the clip in its half-way inserted spread posture. 
   

   DETAILED DESCRIPTION 
   Referring to the drawings and with particular reference to the claims herein, the present construction modifies the connection means between a barrel extension such as item  120  and a barrel such as  40  and also receiver sides such as items (plates)  117 L and  117 R of the aforesaid U.S. Pat. No. 4,693,170 as shown in FIGS. 2, 3, 13 and 31 thereof. In said patent the connection is made between all three of these structures by four rivets  118  which are headed over (clinched) on the outside of plates  117 L arid  117 R. In this construction shown particularly in applicants&#39;  FIG. 6  taken from FIG. 31 of said patent and wherein additional new numbering as added where necessary for clarity starting at  500 , rivets  118  tightly nest in transverse grooves  500  across the top and bottom of the inner end (breech end) of barrel  40  and thereby fix the barrel to barrel extension  120  and thus to receiver section  41  (see aforesaid patent). This structure, of course, prevents removal of the barrel which can cause great inconvenience where it is desired to replace a damaged barrel or to replace the barrel with another type, e.g., from shotgun to rifle. 
   Referring to the present drawings wherein the numbering of parts, where relevant, is the same as in said U.S. Pat. No. 4,693,170 patent, the barrel extension  120  having shell receiving cavity  505  is preferably formed on the outside surfaces of both sides with locator lands  502  having first edge portions  503  which can be of any configuration but preferably of a shape to coincide substantially with second edge portions  501  of apertures  504  formed thru each side  117 L and  117 R of receiver section  41 . Welds such as  506  are formed between the adjacent edges of the lands, or sides of  120  where lands are not provided, and of apertures  504 . In the drawing ( FIG. 5 ) excessive clearance between these adjacent first and second edges is shown, as well as unwelded portions, for clarity. Precision mating of these edges within a few thousandths of an inch, e.g., less than 0.020 in. is highly desirable. The size of lands  502  should be approximately in the proportions shown to assure a joint which is unyielding under rapid fire stresses. 
   Should it be desired to permanently affix the barrel to the barrel extension as shown in the aforesaid patent, rivets  118  may be employed in conjunction with welds  506 . However, in a highly preferred embodiment of the present invention the gun barrel is removably mounted in the forward end of the extension means by a unique and easily disassembled “slot and clip” connector means generally designated  508  and, most preferably, in combination with a barrel clamping mechanism generally designated  510  for tightly securing and stabilizing the barrel within the forward end of the barrel extension. 
   Clip  508  as shown in  FIGS. 4 and 7  comprises a pair of arms  512  and  514  integral with body portion  516  and preferably having rectangular cross-sections. These arms are dimensioned to slide easily thru slots  518  and  520  respectively formed laterally thru extension  120 , and thru slots  522  and  524  respectively formed across the top and bottom of breech end  526  of the barrel. The lateral play of these arms in the slots should be just enough, e.g., from about 0.004 in. to about 0.008 in. to allow easy insertion and sliding of the arms in the slots while preventing longitudinal movement of any significant degree of the barrel relative to the barrel extension. These slots each has a vertical dimension  528  which allows the arms to spread apart as shown in  FIG. 7  as cam surfaces  530  on the insertion ends of the arms slide on the bottom surface  532  of each of slots  522  and  524  in the barrel. 
   Clip  508  is made of metal, e.g., stainless steel which is sufficiently resilient to spring back into the locking position as in  FIG. 4  as the clip is fully inserted thru the slots. As shown in  FIG. 5 , an opening  534  is formed thru each plate  117 L and  117 R to allow insertion of the arms and to allow the inner edge  536  of body portion  516  to lie flush with the barrel extension side, it is preferred that a cut-out  538  be provided in said inner edge  536  to allow for the insertion of a tool such as a screwdriver or knife blade to assist in extracting the clip, if necessary. It is noted that the clip  508  can be inserted thru either side of the receiver section. 
   As shown in the drawings, the aforementioned barrel clamping mechanism comprises a slot  540  Cut longitudinally thru the bottom wall portion  542  of the forward portion of the barrel extension  120  from the front edge  544  thereof back to approximately the barrel abutment shoulder  546  on the wall  547  of the barrel extension  120  bore. Extending down on the sides of slot  540  are projections  548  and  550 . One projection is provided with a threaded bore  552  which receives a tightening means such as a bolt or Allen screw or the like  554 . The clearance between the extension bore wall  547  and the barrel breech end  526  is small such that a tightening turn or so of screw  554  will squeeze wall  547  against breech end  526  of the barrel and further secure it within the extension bore. 
   The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications will be effected with the spirit and scope of the invention.

Technology Classification (CPC): 5