Abstract:
A periscope device specifically adapted to fit in the breach of a firearm. Using a housing equipped with at least a pair of mirrors in parallel relation to one another, a user can look down the barrel of his or her firearm. This is especially useful for checking the barrel for obstructions and for initially bore sighting the firearm when conducting gun sight alignment.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     I. Field of the Invention  
         [0002]     This invention relates generally to periscope devices, and more particularly to periscope devices which enable a person to look down the bore of a rifle even when such a view is out of the user&#39;s direct line of sight.  
         [0003]     II. Discussion of the Prior Art  
         [0004]     Several methods for sighting a rifle are well known in the art. One of these, called bore sighting, generally requires a user to look down the rifle&#39;s barrel to align the barrel with a target bull&#39;s eye and then adjust the sight so it is also on the bull&#39;s eye. This step is needed to ensure a subsequent test shot generally lands somewhere on the paper on which the target is printed. Next, the sight is zeroed. The rifle is placed in a stationary mount, loaded, and a test shot is fired. Next, while the rifle is still being held in place, its sighting scope is further adjusted to place the cross-hairs on the location where the first shot hit the target. Difficulty arises during the bore-sighting phase when sighting certain rifles, automatic weapons and other firearms which do not permit a user to easily look down the bore of the gun.  
         [0005]     Additionally, hard to see obstructions in the barrel of the gun present a safety concern when the weapon is discharged for the first time.  
         [0006]     Therefore, a device is needed which will facilitate bore sighting by enabling a user to look down the bore of a rifle to align the bore with the target and to check for obstructions when this line of sight is not readily accessible.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides for a periscope device comprising a housing shaped to partially fit within the breach of a rifle or other firearm when the housing defines an internal passageway in which two mirrors placed in parallel spaced apart relation to one another and at an angle of 45 degrees to a line of sight. A passageway runs through the housing, and an opening at each of the housing&#39;s ends. The device allows a rifleman to look in one end of the periscope device and see as though he or she was looking directly down the barrel of the rifle.  
         [0008]     These and other objects, features and advantages of the present invention will become readily apparent to those skilled in the art through a review of the following detailed description in conjunction with the claims and accompanying drawings in which like numerals in several views refer to the same corresponding parts. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a perspective view of the periscope device of the present invention;  
         [0010]      FIG. 2  is a side view of the periscope device of the present invention;  
         [0011]      FIG. 3  is a perspective view of the periscope device of the present invention;  
         [0012]      FIG. 4  is a perspective view of the scope mount of the present invention; and  
         [0013]      FIG. 5  is a perspective view of the assembled housing, scope mount and magnification scope of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]     The present invention represents broadly applicable improvements for a bore periscope device designed to be placed in a rifle&#39;s breach so a rifleman can initially bore sight his or her rifle and check for obstructions within the barrel. The embodiments herein are intended to be taken as representative of those in which the invention may be incorporated and are not intended to be limiting.  
         [0015]     Referring first to  FIG. 1 , there is shown a perspective view of a bore periscope assembly. The assembly itself is indicated generally by numeral  10  and includes a housing  12 , mirror mounting surfaces  14  and  16 , viewing opening  18 , conical barrel opening  20 , and an optical passageway  22  (not shown in  FIG. 1 ) running throughout the housing and leading from the viewing opening  18  to a conical barrel opening  20 . Additionally, there is a mounting flange  24  projecting from the side of the device on which a magnification scope mount  26  (see  FIG. 4 ) may be installed.  
         [0016]     With reference to  FIG. 2 , a side view of the bore periscope is shown. The housing  12  is made up of a lower horizontal segment  28 , a vertical segment  30 , and flange  24 . The periscope housing  12  generally has a ⅝″ radius bore that is flattened on the sides to ½″ to fit into a narrow chamber or a larger one. The lower horizontal segment  28  is the part that is placed within the breach of the rifle. The axis of the barrel and of the passageway inside segment  28  is generally aligned. Mirror surfaces  14  and  16  each line the inner walls of the housing at 45 degree angles to the axis of the corresponding passageway length through segments  28  and  30  respectively. Flange  24  extends in a curved fashion from mirror  14  into a small protuberance protruding generally at a right angle to vertical segment  30 . Flange  24  may be used to secure an additional magnification scope mount  26  (see  FIG. 4 ).  
         [0017]     By examining  FIG. 2 , the pathway by which images are reflected through the device is easy to understand. An individual peering through opening  18  sees the reflection off mirror  16 , which is the reflection of mirror  14 , which is the reflection of opening  20 . Therefore, looking through opening  18  gives the same viewpoint as if one were looking out opening  20  from within the rifle&#39;s barrel.  
         [0018]     Referring now to  FIG. 3 , another perspective view of the bore periscope assembly  10  is shown. From this perspective the conical barrel opening  20  can be understood more fully. A short conically tapered section  32  extends from the free end of segment  28 . Four narrow slots  33  are equally spaced about the perimeter of opening  20 . When these slots are viewed as one looks down the bore of the rifle, they appear as peripheral crosshairs. These aid the user in more accurately centering the view of the bore on the target.  
         [0019]      FIG. 4  discloses a magnification scope mount  26 . This scope mount  26  and its corresponding magnification scope  35  (see  FIG. 5 ) are not required to operate the present invention, but when these pieces are added to the device they enhance and enlarge images seen at opening  18 . A scope mount  26  is composed of a clamping device  34 , hoop  36 , and bolt  38 . The scope mount  26  is clamped to the flange  24  of the bore periscope  10  using the bolt to squeeze clamps  34  onto the flange. The hoop  36  of the scope mount is then ready for the magnifying scope  35  to be concentrically inserted. The clamping device and hoop are readily tightened or loosened by turning the bolt  38 .  
         [0020]     Shown in  FIG. 5  is a view of the scope mount  26  and the magnification scope  35  as they would be assembled with respect to the housing  12  of the present invention. The barrel of the scope  35  is secured within the hoop  36  of the scope mount  26 . A viewer looking through scope  35  may then observe the environment outside opening  20  in a magnified view.  
         [0021]     Now that the details of the mechanical construction of the bore periscope of the present invention have been described, consideration will next be given to its mode of operation. The present invention is capable of operating when the user inserts section  24  of the present invention into the breach of the rifle to be sighted, the opening  20  being closest to the barrel. Next, the user looks into opening  18  to see the reflected image of what is seen at opening  20 . The user examines this image for obstructions in the barrel and proceeds to align the crosshairs of his view with the center of the target he would like to hit, which may be 50 yards or more away. He or she then synchronizes the gun&#39;s sight with the same target used. After taking steps to steady the gun in this position by placing it in a stationary mount, e.g. sandbags or a rifle evaluator, the bore periscope of the present invention is removed from the breach of the rifle. The sights are then “zeroed”. More particularly, the gun is loaded and a shot is fired at a target without any movement of the firearm. The scope on the rifle is then adjusted using the existing positioning screws on the scope sight so that its crosshairs align with the location hit by the first shot. In this way, a rifle is sighted in a safe and effective way.  
         [0022]     It can be seen, then, that the present invention provides an improved, versatile, efficient periscope device for bore sighting a rifle. The result is that a safer and more efficient rifle sighting process can be performed. Specifically note that while the description of this device has been primarily described as suitable for rifles, this invention is equally well suited for any firearm with a bore that is difficult to look down once the gun is placed in its stationary mount.  
         [0023]     This invention has been defined herein in considerable detail in order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment details and operating procedures, can be accomplished without departing from the scope of the invention itself