Patent Publication Number: US-7210261-B2

Title: Mounting a sight device on a shoulder automatic or semi-automatic fire arm

Description:
The present invention relates to the mounting of a sight on a firearm such as a semi-automatic or automatic hunting rifle. 
   A sighting system is understood to mean laser viewfinders, telescopic sights or holographic devices. 
   These kinds of firearms comprise a strip into which a magazine extends for holding the ammunition and which ends in a screw onto which a cap can be screwed, said cap having means to prevent accidental unscrewing. 
   On said firearms in order to mount a sight it is necessary to secure means for the attachment of the sight onto the barrel which is a painstaking and costly procedure. 
   The aim of the present invention is to provide a way of mounting which does not require any modification to the firearm. 
   The invention relates to the mounting of a sight on an automatic or semiautomatic shotgun of the type comprising a butt, a breech box, a barrel, a magazine housed in a housing and with a screw at the end designed to receive a threaded securing cap with a notched collar designed to cooperate with an elastic stub at the end of the housing, said mounting being characterised in that it comprises a support having at one end a ring designed to be engaged onto the screw and comprising, on the one hand, a hole designed to receive the elastic stub, and on the other hand a second elastic stub designed to cooperate with the notches of the collar, said ring being in one piece with a tab terminated by a small plate which is folded over to extend above the barrel, means being provided for securing the sight onto the small plate. 
   Thus to mount the sight onto a firearm of this type it is necessary to unscrew the cap and engage the ring onto the screw ensuring a good angular adjustment so that the elastic stub is inserted into the hole then the cap is retightened. 
   According to a structural characteristic the support is made from a metal plate that is cut out to have a ring at one end and the small plate at the other end, these two elements being connected by a tab which is folded so as to extend perpendicular to the ring, said small plate being folded perpendicular to the tab so that the ring and the small plate extend in two perpendicular planes. 

   
     The present invention is described in more detail in the following with reference to a particular embodiment which is given by way of example only and is shown in the attached drawings. 
       FIG. 1  is a plan view of a metal blank cut out to form the support. 
       FIG. 2  is a cross section showing the mounting of the support. 
       FIG. 3  is a perspective view of the support. 
       FIG. 4  is an exploded perspective view showing the mounting. 
       FIG. 5  is an elevated view of a gun equipped with a sight system fixed by means of the mounting according to the invention. 
   

     FIG. 1  shows a plan view of a metal plate cut out to form an almost rectangular section  1 , one long side  2  of which is connected by a tab  3  to a ring  4 . 
   The ring  4  is provided on one face  4   a  with a hole  5  and on the face  4   b  with a flexible stub  6 , the latter being mounted by sliding into a bore closed from the side of the face  4   a  by a screw  8 . 
   The flexible stub  6  has a shoulder  9  cooperating with a shoulder of the bore, a compression spring  11  being inserted between the screw  8  and the stub. 
   As shown in  FIG. 3  the rectangular section  1  is folded over to extend perpendicular to the tab  3 , whilst the edge  3   a  of the tab  3  is folded perpendicular to the ring  4 . In this way section  1  and the ring  4  extend in two perpendicular planes. 
   The rectangular section  1  constitutes the small plate and has tapped holes  12  making it possible to secure the base  15  of a holographic sight  16  using screws  13 . 
   A holographic device is shown by way of example, but a different device could be mounted on section  1 , for example a telescopic or a laser device. 
     FIG. 4  shows the housing  18  of a semiautomatic rifle in which there is a magazine with a screw  19  at the end, the latter projecting at the free end of the housing  18  which comprises a metal ring  20  provided with a resilient stub  21 . 
   Normally, a cap  22  with a collar  23  provided with notches  24  is screwed onto the screw  19 . The stub moves aside partly elastically when the cap  22  is screwed on and acts as a check by cooperating with the notches to prevent the accidental loosening of the cap. 
   According to the invention a ring  4  is placed onto the screw  19  the hole  5  of which receives the stub  21 , which ensures a perfect angular locking, then the cap  22  is tightened, the notches  24  of which corresponding with the stub  6 . 
   In  FIG. 5  a semiautomatic hunting rifle is shown with a butt  26 , a breech box  27  and a barrel  28 . It can be seen that the sight  16  is situated above the barrel  28  in the axis of the sight of the gun. 
   Of course, the invention is not restricted to the embodiment described above and illustrated. It is possible to add numerous modifications to detail without departing from the scope of the invention.