Scope with improved magnification system

Abstract

Various embodiments described herein comprise a scope for a firearm having a large range of zoom. The scope comprising a movable zoom selector for adjusting magnification of an image viewed through the scope. The scope further comprises an objective, an ocular, and an erector assembly positioned between the objective and ocular. The erector assembly comprises at least three optical elements movable relative to one another in response to operation of the zoom selector.

1 . A scope for sighting, the scope comprising:
 a movable zoom selector for adjusting magnification of an image viewed through the scope;   an objective;   an ocular; and   an erector assembly positioned between the objective and ocular, the erector assembly comprising at least three optical elements movable relative to one another in response to operation of the zoom selector.   
   
   
       2 . The scope of  claim 1 , wherein the at least three optical elements cooperate to provide at least 4× zoom. 
   
   
       3 . The scope of  claim 1 , wherein the at least three optical elements cooperate to provide at least 5× zoom. 
   
   
       4 . The scope of  claim 3 , wherein the at least three optical elements span a distance that is equal to or less than about 5 inches. 
   
   
       5 . The scope of  claim 4 , wherein the at least three optical elements span a distance that is equal to or less than about 4 inches. 
   
   
       6 . The scope of  claim 1 , further comprising at least three carriages supporting said at least three optical elements, said three carriages being longitudinally translated in response to operation of the zoom selector. 
   
   
       7 . The scope of  claim 1 , further comprising an erector housing comprising an inner tube and an outer tube surrounding the inner tube, the outer tube having a front slot, a central slot, and a rear slot, the at least three optical elements comprise a first erector element, a second erector element, and a third erector element, a front carriage carrying the first erector element is slidably retained in the front slot, a central carriage carrying the second erector element is slidably retained in the central slot, and a rear carriage carrying the third erector element is slidably retained in the rear slot, and the front, central, and rear carriages are disposed within the inner tube. 
   
   
       8 . The scope of  claim 7 , wherein the front carriage, central carriage, and rear carriage move axially along the erector housing when the zoom selector is rotated. 
   
   
       9 . The scope of  claim 7 , wherein the first erector element comprises a collector lens, the second erector element comprises a lens, and the third erector element comprises a Barlow lens. 
   
   
       10 . The scope of  claim 7 , wherein the third erector element comprises a negative lens. 
   
   
       11 . The scope of  claim 1 , wherein the movable zoom selector is a rotatable ring connected to the erector assembly such that rotation of the ring longitudinally displaces the at least three optical elements. 
   
   
       12 . The scope of  claim 1 , wherein at least one of the three optical elements comprises a Barlow lens. 
   
   
       13 . A scope for sighting, the scope comprising:
 a movable zoom selector for adjusting magnification of an image viewed through the scope;   an objective;   an ocular;   an erector assembly positioned between the objective and ocular, the erector assembly comprising:
 at least three optical elements; 
 at least three separate carriages supporting said at least three optical elements; and 
 a tube having at last three cams, said at least three separate carriages being slidably engaged to said at least three cams such that rotation of said tube induces longitudinal movement of said carriages and said optical elements. 
   
   
   
       14 . A scope for a firearm, the scope comprising:
 an elongate main body; and   an erector assembly disposed within the main body, the erector assembly comprising:
 a collector lens; 
 a zoom lens; 
 a Barlow lens; 
 an erector housing defining at least three elongate cams, movement of the collector lens, zoom lens, and Barlow lens each being guided by one of the elongate cams. 
   
   
   
       15 . The scope of  claim 14 , further comprising a collector lens carriage carrying the collector lens, a zoom lens carriage carrying the zoom lens, and a Barlow lens carriage carrying the Barlow lens, wherein the collector lens carriage, zoom lens carriage, and Barlow lens carriage are guided by the corresponding cams. 
   
   
       16 . The scope of  claim 14 , further comprising a zoom selector ring connected to the erector assembly such that the collector lens, zoom lens, and Barlow lens move relative to one another as the zoom selector ring is rotated. 
   
   
       17 . The scope of  claim 14 , wherein the scope has more than about 4× zoom capability. 
   
   
       18 . The scope of  claim 17 , wherein the maximum distance between the collector lens and the Barlow lens is less than about 6 inches. 
   
   
       19 . The scope of  claim 17 , wherein the maximum distance between the collector lens and the Barlow lens is less than about 4 inches. 
   
   
       20 . The scope of  claim 14 , wherein the scope has more than about 5× zoom capability. 
   
   
       21 . The scope of  claim 14 , wherein the scope has more than about 7× zoom capability.