Rear aperture sight for rifle

Abstract

A rear aperture sight for use in conjunction with a front sight post sight on a rifle. The front sight post has a horizontal top edge and vertical side edges. The rear aperture sight comprises a rear sight adapted to be mounted on the rifle. The rear sight has a horizontally elongated aperture formed therein having height and width dimensions. The width dimension is greater than the height dimension. The aperture is defined by two circular segments s 1 and s 2 having chords c 1 and c 2 , respectively, defined by included angles θ 1 and θ 2 , respectively, of circles having radii R 1 and R 2 , respectively. The chords c 1 and c 2 have heights h 1 and h 2 , respectively. Radii R 1 and R 2 and angles θ 1 and θ 2 are selected such that chords c 1 and c 2 are of equal length. The circular segments are positioned such that chords c 1 and c 2 are co-linear and oriented horizontally. In another aspect, the rear sight has at least one aperture plate having an aperture formed therein which defines an entrance pupil for an eye of a shooter of the rifle. The entrance pupil is horizontally elongated having a height h and a width w, the width w being at least about 125% of the height h, the height h being smaller than a diameter of a pupil of the eye of the shooter and of such a value that the entrance pupil is adapted to cause the horizontal top edge of the front sight post and a horizontal edge of a target to be more sharply focused than if viewed by an unaided eye, the width w being of such a value that an area defined by the entrance pupil is greater than an area defined by a circular entrance pupil having a diameter equal to the height h, thereby permitting more light to pass through the entrance pupil than through the circular entrance pupil, and causing the front sight post and the target to appear brighter than if viewed through the circular entrance pupil.

1 . A rear aperture sight for use in conjunction with a front sight post sight on a rifle, the front sight post having a horizontal top edge and vertical side edges, said rear aperture sight comprising:
 a rear sight adapted to be mounted on the rifle,   said rear sight having a horizontally elongated aperture formed therein having a height h and a width w, said width w being greater than said height h,   said height h being of such a value that said aperture is adapted to cause the horizontal top edge of the front sight post and a horizontal edge of a target to be sharply focused,   said width w being of such a value that said aperture is adapted to permit a sufficient amount of light to pass therethrough so that the front sight post and the target are bright,   wherein said aperture is defined by two circular segments s 1  and s 2  having chords c 1  and c 2 , respectively, defined by included angles θ 1  and θ 2 , respectively, of circles having radii R 1  and R 2 , respectively, said chords c 1  and c 2  having heights h 1  and h 2 , respectively,   wherein said radii R 1  and R 2  and said angles θ 1  and θ 2  are selected such that said chords c 1  and c 2  are of equal length,   wherein said circular segments are positioned such that said chords c 1  and c 2  are co-linear and oriented horizontally.   
     
     
         2 . The sight of  claim 1  wherein R 1 =R 2 =R and θ 1 =θ 2 =θ. 
     
     
         3 . The sight of  claim 1  wherein R 1 =R 2  and θ 1 ≠θ 2 . 
     
     
         4 . The sight of  claim 1  wherein w=c 1 =c 2 , w being in a range of about 0.011 inch to about 0.20 inch, and wherein h=h 1 +h 2 , h being in a range of about 0.010 inch to about 0.100 inch. 
     
     
         5 . A rear aperture sight for use in conjunction with a front sight post sight on a rifle, the front sight post having a horizontal top edge and vertical side edges, said rear aperture sight comprising:
 a rear sight adapted to be mounted on the rifle,   said rear sight having at least one aperture plate,   said at least one aperture plate having an aperture formed therein,   said aperture defining an entrance pupil for an eye of a shooter of the rifle, said entrance pupil being horizontally elongated,   said horizontally elongated entrance pupil having a height h and a width w, said width w being at least about 125% of said height h,   said height h being smaller than a diameter of a pupil of the eye of the shooter and of such a value that said entrance pupil is adapted to cause the horizontal top edge of the front sight post and a horizontal edge of a target to be more sharply focused than if viewed by an unaided eye,   said width w being of such a value that an area defined by said entrance pupil is greater than an area defined by a circular entrance pupil having a diameter equal to said height h, thereby permitting more light to pass through said entrance pupil than through the circular entrance pupil, and causing the front sight post and the target to appear brighter than if viewed through the circular entrance pupil.   
     
     
         6 . The sight of  claim 5  where said at least one aperture plate is a single aperture plate having a circular aperture formed therein, said circular aperture having an axis, said aperture plate adapted to be mounted relative to the rifle such that said circular aperture axis is inclined at an angle relative to a bore of a barrel of the rifle. 
     
     
         7 . The sight of  claim 6  wherein said circular aperture is formed in said aperture plate such that said circular aperture axis is substantially perpendicular to said aperture plate, and said aperture plate is adapted to be mounted relative to the rifle such that said aperture plate is inclined at an angle relative to the bore of the barrel of the rifle. 
     
     
         8 . The sight of  claim 6  wherein said circular aperture is formed in said aperture plate such that said circular aperture axis is inclined at an angle relative to said aperture plate, and said aperture plate is adapted to be mounted relative to the rifle such that said aperture plate is substantially perpendicular relative to the bore of the barrel of the rifle. 
     
     
         9 . The sight of  claim 5  wherein said at least one aperture plate is at least two aperture plates, each said aperture plate having an aperture formed therein, and wherein said at least two aperture plates are offset vertically such that their common open areas define said entrance pupil. 
     
     
         10 . The sight of  claim 9  wherein said apertures are circular. 
     
     
         11 . The sight of  claim 9  wherein said apertures are square. 
     
     
         12 . The sight of  claim 9  wherein said apertures are triangular, and wherein said triangular apertures are inverted relative to one another. 
     
     
         13 . The sight of  claim 5  wherein said at least one aperture plate is a transparent substrate and said aperture is formed by adding an opaque mask to said transparent substrate. 
     
     
         14 . The sight of  claim 5  wherein w is in a range of about 0.0125 inches to about 0.20 inches, and wherein h is in a range of about 0.010 inches to about 0.100 inches. 
     
     
         15 . The sight of  claim 5  wherein said width w is in a range of about 125% to about 500% of said height h. 
     
     
         16 . The sight of  claim 5  wherein said width w is in a range of about 150% to about 400% of said height h. 
     
     
         17 . The sight of  claim 5  wherein said width w is in a range of about 200% to about 300% of said height h. 
     
     
         18 . The sight of  claim 5  wherein a geometric shape of said entrance pupil is selected from a group of geometric shapes consisting of ovals, ellipses, rectangles, and hexagons. 
     
     
         19 . The sight of  claim 5  wherein a geometric shape of said aperture is selected from a group of geometric shapes consisting of circles, squares, rectangles, triangles, ellipses, and ovals. 
     
     
         20 . The sight of  claim 5  wherein said at least one aperture plate has a thickness in a range of about 0.0005 inches to about 0.500 inches. 
     
     
         21 . The sight of  claim 5  wherein said at least one aperture plate has a thickness in a range of about 0.001 inches to about 0.250 inches. 
     
     
         22 . The sight of  claim 5  wherein said at least one aperture plate has a thickness in a range of about 0.002 inches to about 0.125 inches. 
     
     
         23 . A rifle having a receiver and a barrel, said rifle comprising:
 A front sight post mounted on said barrel of said rifle, said front sight post having a horizontal top edge and vertical side edges,   a rear sight mounted on said receiver of said rifle,   said rear sight having at least one aperture plate,   said at least one aperture plate having an aperture formed therein,   said aperture defining an entrance pupil for an eye of a shooter of said rifle, said entrance pupil being horizontally elongated,   said horizontally elongated entrance pupil having a height h and a width w, said width w being at least about 125% of said height h,   said height h being smaller than a diameter of a pupil of the eye of the shooter and of such a value that said entrance pupil is adapted to cause said horizontal top edge of said front sight post and a horizontal edge of a target to be more sharply focused than if viewed by an unaided eye,   said width w being of such a value that an area defined by said entrance pupil is greater than an area defined by a circular entrance pupil having a diameter equal to said height h, thereby permitting more light to pass through said entrance pupil than through the circular entrance pupil, and causing said front sight post and the target to appear brighter than if viewed through the circular entrance pupil.   
     
     
         24 . A combination rear aperture sight and front sight post for use on a rifle, said combination comprising:
 a front sight post adapted to be mounted on a barrel of the rifle, said front sight post having a horizontal top edge and vertical side edges,   a rear sight adapted to be mounted on the rifle,   said rear sight having at least one aperture plate,   said at least one aperture plate having an aperture formed therein,   said aperture defining an entrance pupil for an eye of a shooter of the rifle, said entrance pupil being horizontally elongated,   said horizontally elongated entrance pupil having a height h and a width w, said width w being at least about 125% of said height h,   said height h being smaller than a diameter of a pupil of the eye of the shooter and of such a value that said entrance pupil is adapted to cause said horizontal top edge of said front sight post and a horizontal edge of a target to be more sharply focused than if viewed by an unaided eye,   said width w being of such a value that an area defined by said entrance pupil is greater than an area defined by a circular entrance pupil having a diameter equal to said height h, thereby permitting more light to pass through said entrance pupil than through the circular entrance pupil, and causing said front sight post and the target to appear brighter than if viewed through the circular entrance pupil.