Firearm Frame Lug Tension Post Adjusting Fit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hinged assembly and dismantling systems in firearms, such as pistols, face challenges in achieving a precise and durable fit between components due to manufacturing variations and wear, leading to play or motion issues that accelerate component wear and require frequent maintenance or replacement.
Innovation Solution
A frame lug with a tension post and lock screw mechanism that provides a solid metal-to-metal fit, adjustable to compensate for manufacturing tolerances and wear, allowing for precise alignment and secure locking without modifying existing firearm components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rubber plug is used to minimize play between receiver and frame, then initial fit is improved, but the solution deteriorates over time due to wear and provides inconsistent pressure
Solution Approach 1:
The patent changes the material parameter from rubber to metal and adjusts the geometric parameter of the contact surface through the tension post to achieve consistent metal-to-metal contact pressure that maintains reliability over the service life of the firearm
Solution Approach 2:
The patent replaces the durable but inconsistent rubber plug with an adjustable metal tension post system that provides long-lasting consistent pressure without the deterioration problems of rubber materials
2Manufacturing precision
If manufacturing precision is increased to eliminate play between components, then fit quality is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent introduces an adjustable tension post that allows dynamic adjustment of the contact pressure and position between receiver and frame, enabling standard manufacturing tolerances to achieve precise fit through field adjustment rather than requiring ultra-precise manufacturing
Solution Approach 2:
The patent changes the geometric parameter of the contact interface by allowing adjustment of the tension post height and position, compensating for manufacturing variations without requiring tighter manufacturing tolerances
Data Source
AI summary
A frame lug for a firearm having a receiver or barrel hingedly mounted to a frame is provided with a tension post having an external thread that adjustably engages with an internal thread of a vertical bore in the frame lug. The tension post provides a height adjustable top surface upon which the receiver or barrel rests when in a closed position and maintains a tight metal-to-metal connection to improve precision of fitting together the receiver or barrel and the frame. Firearms may have the frame lug installed therein or be retro-fitted with the frame lug. In a retro-fitting method, the firearm's frame lug is removed, a threaded vertical bore is machined at least partially into the frame lug, and an externally threaded tension post is adjustably engaged with the vertical bore such that a top surface of the tension post provides a tight fit with the receiver or barrel.