Patent Publication Number: US-6216351-B1

Title: Day and night weapon sights

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to sighting devices for projectile weapons, such as archery bows and personal firearms. In preferred embodiments, the present invention relates to weapon sights which can be used effectively for both day and night weapon sightings. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Projectile weapons, especially personal firearms, such as rifles, shotguns and pistols, are typically aimed at targets using some form of sighting device. In this regard, the sighting device is typically fixed to the gun in alignment with the sight line of the gun barrel. In such a manner, the gun&#39;s barrel may be brought to bear on a visually acquired target so that a high likelihood exists that the target will be hit when the gun is discharged. 
     In copending U.S. patent application Ser. No. 09/038,065 filed on Mar. 11, 1998 (the entire content of which is expressly incorporated hereinto by reference), there are disclosed gun sights which include one or more rod-shaped light guides. In preferred embodiments, the gun sights of the copending &#39;065 patent application include one or more light guides that are formed from a suitable optically clear plastics material and dyed or colored with a fluorescent pigment to enhance their visibility. 
     While the gun sights disclosed in the copending &#39;065 patent application are entirely satisfactory for daylight gun sightings, their use at night is limited due to the minimal amount of ambient light that is usually available. 
     Broadly, the present invention is embodied in combination day and night weapon sighting devices which necessarily include at least one rod-shaped light guide and a visible self-luminescent capsule closely vertically adjacent thereto. 
    
    
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
     Reference will hereinafter be made to the accompanying drawings wherein like reference numerals throughout the various FIGURES denote like structural elements, and wherein, 
     FIG. 1 is a rear perspective view of a handgun which is provided with front and rear gun sights in accordance with the present invention; 
     FIG. 2 is an enlarged rear perspective view of the gun sights employed on the handgun depicted in FIG. 1; and 
     FIG. 3 is an even further enlarged rear elevation view showing front and rear gun sight alignment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Front and rear gun sights  10 ,  20 , respectively, in accordance with one embodiment of the present invention are shown in accompanying FIG. 1 positioned along the sight line of a typical handgun HG. In this regard, it will be appreciated that, although the sights  10 ,  20  in accordance with the present invention are depicted in FIG. 1 as being mounted to handgun HG and will be described in greater detail in that exemplary environment of use, the gun sights disclosed hereinafter also find utility when combined with shoulder-mounted firearms (e.g., rifles, shotguns and the like) as well as archery bow weapons. 
     It will be observed that the front sight  10  is positioned along the barrel B of the handgun HG at its forward end, while the rear gun sight is aligned with the front sight along the barrel, but positioned at its rearward end. In such a manner, therefore, the user of the handgun HG will be able to bring the barrel B to bear accurately on a visually acquired target by bringing the front and rear sights  10 ,  20 , respectively, into visual alignment with one another and with the intended target. By aiming the handgun HG in this way, the user will have a high probability of striking the target when discharged. 
     The gun sights  10 ,  20  are shown in greater detail in accompanying FIG.  2 . In this regard, it will be observed that the front gun sight includes an axially elongate mounting base member  10 - 1 . The base member  10 - 1  is provided with an upwardly projecting, central ridge  10 - 2 . The ridge  10 - 2  is joined to side walls  10 - 3 ,  10 - 4  by opposed, concave transition surfaces  10 - 5 ,  10 - 6 , respectively. The ridge  10 - 2  is itself provided at its apex with an axially extending semi-cylindrical concave surface  10 - 7  which conforms closely to the circular cross-section of the rod-shaped light guide  10 - 8 . 
     The mounting base  10 - 1  also defines a lower channel  10 - 9  extending its entire lengthwise dimension. The channel  10 - 9  is dimensioned so as to fit onto the barrel B of the handgun HG. The base  10 - 1  is also provided with opposed pairs of set screws  10 - 10 ,  10 - 11  and corresponding threaded apertures  10 - 12 ,  10 - 13 , respectively. The threaded apertures  10 - 10 , 10 - 11  extend substantially perpendicularly to the longitudinal dimension of the channel  10 - 9  and thereby allow their respective set screws  10 - 12 ,  10 - 13  to extend into the channel  10 - 9 . The proximal ends of the set screws  10 - 10 ,  10 - 11  are provided with suitable surfaces to accept a turning tool, while the distal ends thereof enter the channel  10 - 9  and bear against the barrel B of the handgun HG so as to positionally fix the mounting base  10 - 1 , and hence the sight  10 , thereto. 
     Importantly, the front sight  10  is also provided with a fixed-position, self-luminescent capsule  10 - 14  which continuously emits a point or dot of light. Most preferably, the self-luminescent capsule  10 - 14  is a radioactive luminescent source, such as tritium, as disclosed more fully in U.S. Pat. Nos. 4,020,203; Re. 35,347 and 5,878,521 (the entire content of each being incorporated expressly hereinto by reference). The capsule  10 - 14  is fixedly inserted into the rearward vertical surface of the mounting base  10 - 1  so as to be in close vertical alignment with the rearward end of the light guide  10 - 8 . Specifically, the capsule  10 - 14  is aligned with a vertical plane parallel to the aiming axis Aa which bisects both the capsule  10 - 14  and the light guide  10 - 8 . 
     The rear sight  20 , like the front sight  10 , includes a mounting base  20 - 1  provided with a laterally separated (relative to the aiming axis Aa) parallel apical protrusions  20 - 2 ,  20 - 3 . Each protrusion includes a semicylindrical concave surface  20 - 4 ,  20 - 5  which receive therein a respective one of the rod-shaped light guides  20 - 6 ,  20 - 7 . A generally rectangular lower channel  20 - 8 , and paired threaded apertures  20 - 9 ,  20 - 10  and set screws  20 - 11 ,  20 - 12  are proved for the same purposes as their corresponding structure in front sight  10  - that is, to positionally fix the sight  20  to the barrel B of the handgun HG. 
     The rearward vertical surface of each of the apical protrusions  202 ,  20 - 3  is provided with self-luminescent capsules  20 - 14 ,  20 - 15 , respectively. Each of the self-luminescent capsules is inserted into the rear surface of the apical protrusions  20 - 2 ,  20 - 3  so as to be fixedly positioned immediately vertically adjacent the rearward end of the light guides  20 - 6 ,  20 - 7 , respectively. That is, a vertical bisecting plane parallel to the aiming axis A a  bisects both the capsules  20 - 14 ,  20 - 15  and their respective the light guides  20 - 6  and  20 - 7 . 
     The apical protrusions  20 - 2  and  20 - 3  are separated by a semi-cylindrical valley  20 - 16  which extends longitudinally in alignment with the aiming axis A a . Most preferably, the radius of the semi-cylindrical surface is in close conformance to the radius of the capsule  10 - 14  of the front sight  10 . In addition, as is evident from FIG. 3, the generatrices of the semi-cylindrical valley  20 - 16  are aligned with a horizontal plane which bisects both the capsules  20 - 14  and  20 - 15  as well as the capsule  10 - 14  when the front and rear sights  10 ,  20 , respectively, are aligned along the aiming axis A a . When aligned in such a manner as depicted in FIG. 3, the user of the handgun HG will be visually confident that the handgun HG is aimed properly. 
     It will be noted that the relative diameter of the light guide  10 - 8  is different as compared to the diameters of each of the light guides  20 - 6 ,  20 - 7 . More specifically, the diameter of the front light guide  10 - 8  is approximately at least about 25% larger than the diameters of the rear light guides  20 - 6 ,  20 - 7 . Thus, when the front and rear sights  10  and  20 , respectively, are longitudinally separated along the barrel B of the handgun HG as shown in FIG. 1, the perceived diameter of the front light guide  10 - 8  will decrease so that it visually appears to be substantially the same diameter as the pair of rear light guides  20 - 6 ,  20 - 7 . In other words, FIG. 3 shows the literal non-perspective dimensional relationship between the light guides  10 - 8  on the one hand, and the light guides  20 - 6 ,  20 - 7  on the other hand. In use, the sight picture will be such that the front light guide  10 - 8  will appear to have substantially the same diameter as the light guides  20 - 6 ,  20 - 7  since the front and rear sights  10 ,  20  will be viewed in a background/foreground perspective. The relative diameters of the front and rear light guides  10 - 6  and  20 - 6 ,  20 - 7  can therefore be selected in dependence upon their relative separation distance when positioned on a weapon so that the relative diameters of the front and rear light guides  10 - 6  and  20 - 6 ,  20 - 7  will visually appear to be substantially the same when a user aims the weapon. 
     The light guides employed in the gun sights of the present invention are, in and of themselves, highly conventional. In this regard, the light guides are typically formed from a suitable optically clear plastics material such as polystyrene, polyacrylic or polytetrafluoroethylene, and are most preferably dyed or colored with a fluorescent pigment to enhance their visibility. The light guide may optionally be provided with an optically transparent coating thereon of a suitable plastics material and/or may be provided with a scratch-resistant sleeve member. The light guides are rod-shaped elements having lengths between about 0.50 to about 1.5 inches and a diameter between about 0.055 to about 0.250 inch and more preferably between about 0.075 to about 0.125 inch. In particularly preferred embodiments, the light guides for the front and rear sights  10 ,  20 , respectively, will be between about 0.60 and about 1.40 inch in length (±0.015 inch) and will have diameters ranging between about 0.090 to about 0.118 inch (±0.004 inch). 
     Similarly, the self-luminescent capsule  10 - 14  is somewhat larger in diameter as compared to the capsules  20 - 14  and  20 - 15  for the same reasons noted above. Most preferably, the capsules will have a diameter of between about 0.050 to about 0.100 inch, with the front capsule  10 - 14  being typically about 0.094 inch and the rear capsules  20 - 14 ,  20 - 15  being about 0.087 inch. In use, therefore, the front capsule  10 - 14  will visually appear to be smaller than its actual diameter so as to appear roughly equivalent in diameter as compared to the rear capsules  20 - 14 ,  20 - 15  for the same reasons noted previously. 
     The vertical separation distances of the light guides and self-luminescent capsules will depend upon the specific diameters employed. Preferably, the light guides and capsules are positioned as closely adjacent as possible without affecting the structural integrity of the sight. For example, the closest parallel lines tangent to the circumferences of the light guide and the capsules will usually be separated by a distance of less than about 0.050 inch, and typically less than about 0.035 inch. 
     Because of the relatively close vertical separation between the light guides  10 - 8 ,  20 - 6  and  20 - 7  and their respective self-luminescent capsules  10 - 14 ,  20 - 14  and  20 - 15 , minimal elevational deviation will occur at the zeroed range of the sights  10 ,  20 . As a result, the user can confidently use the sight pictures provided by the sights  10  and  20  for both day and night firing. That is, the light guides  10 - 8 ,  20 - 6  and  20 - 7  will be aligned and brought to bear on the target during daylight hours since they will be more clearly visible to the user. During low light and night light conditions, however, the self-luminescent capsules  10 - 14 ,  20 - 14  and  20 - 15  will be more clearly visible thereby allowing them to be aligned and brought to bear on a target. In such a manner, therefore the sights  10 ,  20  can be employed for both day and night firing. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.