Telescopic Sight Prism Adjustment Mechanism
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Solution Overview
Problem
The existing tilting inner tube mechanism in telescopic gun sights is limited in reticle adjustment range, interferes between vertical and horizontal movements, requires precise and costly joint mechanisms, and is prone to hysteresis issues, leading to inaccuracies in point of aim adjustments.
Innovation Solution
An optical method using a pair of prisms positioned between the objective lens and reticle, where changing the linear separation between the prisms adjusts the point of aim, eliminating mechanical reticle movement and allowing independent elevation and windage adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a tilting inner tube mechanism is used to adjust the reticle position, then the point of aim can be adjusted vertically and horizontally, but the adjustment range is limited by the clearance between the inner tube and the scope's main tube
Solution Approach 1:
The patent replaces the mechanical tilting inner tube system with an optical system using two prisms. The prisms are positioned to receive light from the objective lens and direct it to the reticle. By moving one prism relative to the other along the optical axis, the point of aim is adjusted optically rather than mechanically, eliminating the clearance limitation and enabling virtually unlimited adjustment range.
Solution Approach 2:
The invention changes the adjustment parameter from the tilt angle of the inner tube to the linear separation distance between two prisms. This parameter change allows for greater adjustment range because the linear movement of prisms is not constrained by the circular clearance between tubes, and the adjustment range can be extended by simply increasing the travel distance of the prisms along the optical axis.
2Ease of operation
If a tilting inner tube mechanism is used, then reticle position can be adjusted, but vertical and horizontal movements interfere with each other near the ends of the adjustment range
Solution Approach 1:
The patent divides the adjustment function into two independent prism pairs: one pair for vertical (elevation) adjustment and another pair for horizontal (windage) adjustment. Each prism pair operates independently along its own axis, eliminating the interference between vertical and horizontal movements that occurs in the tilting tube mechanism where a single tube must perform both functions simultaneously.
3Manufacturing precision
If a tilting inner tube mechanism is used, then the reticle can be moved to adjust point of aim, but a precise and expensive joint mechanism is required at the rear end of the inner tube
Solution Approach 1:
The patent eliminates the complex ball-and-socket joint mechanism by replacing the mechanical tilting system with an optical prism system. The prisms are mounted on simple linear translation stages that move along the optical axis, requiring only straightforward linear guides and actuators rather than precision spherical joints, thereby reducing device complexity and cost.
4Ease of operation
If a tilting inner tube mechanism with adjustment knob and return spring is used, then the inner tube can be tilted for adjustment, but hysteresis issues occur leading to inaccuracies in point of aim adjustments
Solution Approach 1:
The patent replaces the spring-loaded tilting mechanism with an optical prism translation system actuated by precision motors or micromechanical actuators. This eliminates the hysteresis inherent in spring-mechanical systems because the prism position can be controlled with high precision through direct electromagnetic or piezoelectric actuation, providing repeatable and accurate point of aim adjustments without the backlash and friction issues of mechanical springs and joints.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables virtually unlimited adjustment range, independent elevation and windage, reduces weight and bulk, improves reliability, and simplifies manufacturing by eliminating the need for precision joints and hysteresis-prone mechanisms.
Implementation Method 1
a prismatic optical system is used to shift the image of the target on the reticle... a pair of prisms positioned between the objective lens and reticle, where changing the linear separation between the prisms adjusts the point of aim
Data Source
AI summary
Telescopic sights commonly include a reticle which is laterally moved to adjust for the point of aim. In this invention, a prismatic device is used to move the image of the target on the reticle. In one embodiment, a pair of prisms are placed in the optical path of a telescopic sight such that at least one prism is movable along the optical axis. The point of aim is adjusted by adjusting the distance between the two prisms. By replacing the lateral movement of the reticle with the longitudinal movement of a prism, this invention eliminates several drawbacks associated with the prior art including limitations in the adjustment range.