Rear Sight for Firearm

Abstract

A rear sight comprises a base member and a top member. The base member comprises a fitting portion and a base member bearing surface. The fitting portion of the base member is attachable to a firearm. The top member comprises a rear sight alignment portion and a top member bearing surface. The top member bearing surface is slidably engageable with the base member bearing surface for pivotable movement of the top member relative to the base member between lowered and raised positions. Movement of the top member away from the lowered position and toward the raised position increases the distance between the rear sight alignment portion and a barrel axis of the firearm to thereby adjust the elevation of the rear sight alignment portion of the rear sight.

What is claimed is: 
     
         1 . A rear sight for use in a firearm, the firearm including a barrel having a longitudinal barrel axis, a front sight having a front sight alignment portion, and a rear sight receiving portion, the rear sight receiving portion having a rear sight receiving slot rearwardly spaced from the front sight, the rear sight comprising:
 a base member comprising a fitting portion and at least one base member bearing surface, the fitting portion of the base member being shaped and configured to be inserted into and retained in the sight receiving slot of the firearm;   a top member comprising a rear sight alignment portion and at least one top member bearing surface, the rear sight alignment portion being adapted to be aligned with the front sight alignment portion of the firearm;   the at least one top member bearing surface being slidably engageable with the at least one base member bearing surface for pivotable movement of the top member relative to the base member between a lowered position and a raised position, the base member and the top member being configured such that pivoting movement of the top member relative to the base member away from the lowered position and toward the raised position increases the distance between the rear sight alignment portion and the barrel axis of the firearm to thereby adjust the elevation of the rear sight alignment portion of the rear sight when the rear sight is attached to the firearm via the rear sight receiving slot, the base member being of a unitary, one-piece construction, the top member being of a unitary, one-piece construction.   
     
     
         2 . A rear sight as set forth in  claim 1  wherein the at least one top member bearing surface is slidably engageable with the at least one base member bearing surface for pivotable movement of the top member relative to the base member about a laterally extending elevation adjusting axis between the lowered and raised positions, the top member and the base member being adapted and configured such that the elevation adjusting axis is generally parallel to the slot axis when the rear sight is attached to the firearm via the rear sight receiving slot. 
     
     
         3 . A rear sight as set forth in  claim 1  wherein the at least one top member bearing surface comprises at least one arcuate bearing surface having a radius of curvature, and wherein the at least one base member bearing surface comprises at least one arcuate bearing surface having a radius of curvature, the at least one arcuate bearing surface of the top member being slidably engageable with the at least one arcuate bearing surface of the base member for pivotable movement of the top member relative to the base member between the lowered and raised positions. 
     
     
         4 . A rear sight as set forth in  claim 3  wherein the radius of curvature of the at least one arcuate bearing surface of the top member is substantially similar to the radius of curvature of the at least one arcuate bearing surface of the base member. 
     
     
         5 . A rear sight as set forth in  claim 3  wherein the at least one arcuate bearing surface of the top member is adapted to nest with the at least one arcuate bearing surface of the base member. 
     
     
         6 . A rear sight as set forth in  claim 5  wherein the at least one arcuate bearing surface of the base member is concave and wherein the at least one arcuate bearing surface of the top member is convex. 
     
     
         7 . A rear sight for use in a firearm, the firearm including a barrel having a longitudinal barrel axis, a front sight having a front sight alignment portion, and a rear sight receiving portion, the rear sight receiving portion being rearwardly spaced from the front sight, the rear sight comprising:
 a base member comprising a fitting portion and at least one base member bearing surface, the fitting portion being operatively attachable to the rear sight receiving portion of the firearm;   a top member comprising a rear sight alignment portion and at least one top member bearing surface, the rear sight alignment portion being adapted to be aligned with the front sight alignment portion of the firearm, the at least one top member bearing surface being slidably engageable with the at least one base member bearing surface for pivotable movement of the top member relative to the base member about a laterally extending elevation adjusting axis between a lowered position and a raised position, the base member and the top member being configured such that the elevation adjusting axis is generally perpendicular to a plane containing the barrel axis for all pivoting movement of the top member relative to the base member between the lowered and raised positions when the rear sight is operatively attached to the firearm via the rear sight receiving portion, the base member and the top member being configured such that the elevation adjusting axis is spaced from the base member for all pivoting movement of the top member relative to the base member between the lowered and raised positions, the base member and the top member being configured such that pivoting movement of the top member relative to the base member away from the lowered position and toward the raised position increases the distance between the rear sight alignment portion and the barrel axis of the firearm to thereby adjust the elevation of the rear sight alignment portion of the rear sight when the rear sight is operatively attached to the firearm via the rear sight receiving portion.   
     
     
         8 . A rear sight as set forth in  claim 7  wherein the base member and the top member are configured such that the elevation adjusting axis is spaced a fixed distance from the base member for all pivoting movement of the top member relative to the base member between the lowered and raised positions. 
     
     
         9 . A rear sight as set forth in  claim 8  wherein the at least one top member bearing surface comprises at least one arcuate bearing surface having a radius of curvature, and wherein the at least one base member bearing surface comprises at least one arcuate bearing surface having a radius of curvature, the at least one arcuate bearing surface of the top member being slidably engageable with the at least one arcuate bearing surface of the base member for pivotable movement of the top member relative to the base member between the lowered and raised positions. 
     
     
         10 . A rear sight as set forth in  claim 9  wherein the radius of curvature of the at least one arcuate bearing surface of the top member is substantially similar to the radius of curvature of the at least one arcuate bearing surface of the base member. 
     
     
         11 . A rear sight as set forth in  claim 9  wherein the at least one arcuate bearing surface of the top member is adapted to nest with the at least one arcuate bearing surface of the base member. 
     
     
         12 . A rear sight as set forth in  claim 11  wherein the at least one arcuate bearing surface of the base member is concave and wherein the at least one arcuate bearing surface of the top member is convex. 
     
     
         13 . A rear sight as set forth in  claim 7  further comprising a fastener for adjustably locking the top member to the base member, the fastener being moveable between a released position and a locked position, the top member being moveable relative to the base member between the lowered and raised positions when the fastener is in the released position, the top member being locked against movement relative to the base member when the fastener is in the locked position. 
     
     
         14 . A rear sight as set forth in  claim 13  wherein the fastener comprises a threaded shaft and a shoulder, the base member comprises a threaded hole for threadably receiving the threaded shaft, the top member includes a through slot sized for passage therethrough of the threaded shaft, the slot being sized to permit movement of the top member relative to both the fastener and the base member between the lowered and raised positions when the fastener is in the released position, the threaded shaft of the fastener being threaded into the threaded hole sufficiently to cause the top member to be pressed between the shoulder and the base member when the fastener is in the locked position. 
     
     
         15 . A rear sight as set forth in  claim 14  wherein the rear sight receiving portion of the firearm includes a sight receiving slot extending generally along a laterally extending slot axis, and wherein the fitting portion of the base member is shaped and configured to be inserted into and retained in the sight receiving slot. 
     
     
         16 . A rear sight as set forth in  claim 15  wherein the fitting portion of the base member is moveable relative to the sight receiving slot for adjusting drifting of the rear sight. 
     
     
         17 . A rear sight as set forth in  claim 16  further comprising at least one set screw having a threaded shaft, the base member comprising a through set screw receiving hole, the set screw receiving hole having a thread for threadably receiving the threaded shaft of the set screw, the set screw being threadably moveable relative to the base member between a set screw released position and a set screw locked position, the set screw and base member being adapted for engagement of the set screw with the rear sight receiving portion of the firearm to prevent movement of the base member relative to the rear sight receiving portion of the firearm when the set screw is in the locked position. 
     
     
         18 . A rear sight as set forth in  claim 17  wherein the top member includes a through access hole adapted to permit access to the set screw through the access hole when the top member bearing surface is in engagement with the base member bearing surface and the fastener is in the locked position. 
     
     
         19 . A rear sight as set forth in  claim 7  wherein the rear sight receiving portion of the firearm includes a sight receiving slot extending generally along a laterally extending slot axis, and wherein the fitting portion of the base member is shaped and configured to be inserted into and retained in the sight receiving slot. 
     
     
         20 . A rear sight as set forth in  claim 19  wherein the fitting portion of the base member is moveable relative to the sight receiving slot for adjusting drifting of the rear sight. 
     
     
         21 . A rear sight as set forth in  claim 20  further comprising at least one set screw having a threaded shaft, the base member comprising a through set screw receiving hole, the set screw receiving hole having a thread for threadably receiving the threaded shaft of the set screw, the set screw being threadably moveable relative to the base member between a set screw released position and a set screw locked position, the set screw and base member being adapted for engagement of the set screw with the rear sight receiving portion of the firearm to prevent movement of the base member relative to the rear sight receiving portion of the firearm when the set screw is in the locked position. 
     
     
         22 . A rear sight as set forth in  claim 21  wherein the top member includes a through access hole adapted to permit access to the set screw through the access hole when the top member bearing surface is in engagement with the base member bearing surface and the fastener is in the locked position. 
     
     
         23 . A rear sight as set forth in  claim 7  wherein the base member and the top member are configured such that the spacing between the elevation adjusting axis and the base member varies as the top member is moved between the lowered and raised positions. 
     
     
         24 . A rear sight as set forth in  claim 7  wherein the base member is of a unitary, one-piece construction, and wherein the top member is of a unitary, one-piece construction. 
     
     
         25 . A method of using a rear sight as set forth in  claim 7  comprising:
 operatively attaching the fitting portion of the base member to a rear sight receiving portion of a firearm; 
 sliding the at least one top member bearing surface along the at least one base member bearing surface to pivotally move the top member relative to the base member about the laterally extending elevation adjusting axis between the lowered and raised positions. 
 
     
     
         26 . A rear sight for use in a firearm, the firearm including a barrel having a longitudinal barrel axis, a front sight having a front sight alignment portion, and a slide portion, the slide portion having a rear sight receiving slot, the rear sight receiving slot extending generally along a laterally extending slot axis, the rear sight receiving slot being rearwardly spaced from the front sight, the rear sight comprising:
 a base member comprising a fitting portion and at least one base member bearing surface, the fitting portion of the base member being shaped and configured to be inserted into and retained in the sight receiving slot of the slide portion of the firearm;   a top member comprising a rear sight alignment portion and at least one top member bearing surface, the rear sight alignment portion being adapted to be aligned with the front sight alignment portion of the firearm;   the at least one top member bearing surface being slidably engageable with the at least one base member bearing surface for pivotable movement of the top member relative to the base member about a laterally extending elevation adjusting axis between a lowered position and a raised position, the top member and the base member being adapted and configured such that the elevation adjusting axis is generally parallel to the slot axis when the rear sight is attached to the slide portion of the firearm via the rear sight receiving slot, the base member and the top member being configured such that the elevation adjusting axis is spaced from the base member, the base member and the top member being configured such that pivoting movement of the top member relative to the base member away from the lowered position and toward the raised position increases the distance between the rear sight alignment portion and the barrel axis of the firearm to thereby adjust the elevation of the rear sight alignment portion of the rear sight when the rear sight is attached to the slide portion of the firearm via the rear sight receiving slot.   
     
     
         27 . A rear sight as set forth in  claim 26  wherein the at least one top member bearing surface comprises at least one arcuate bearing surface having a radius of curvature, the at least one arcuate bearing surface of the top member being spaced a distance from the elevation adjusting axis that is substantially equal to the radius of curvature of the at least one arcuate bearing surface of the top member. 
     
     
         28 . A rear sight as set forth in  claim 26  wherein the at least one base member bearing surface comprises at least one arcuate bearing surface having a radius of curvature, the at least one arcuate bearing surface of the base member being spaced a distance from the elevation adjusting axis that is substantially equal to the radius of curvature of the at least one arcuate bearing surface of the base member.