Bolt Carrier Staged Piston Actuation Wear Reduction
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Solution Overview
Problem
Gas piston operating systems in firearms are prone to rattling and wear due to loose fits and physical gaps between components, leading to potential damage and reduced reliability.
Innovation Solution
A staged piston actuation system that pre-tensions the mechanical linkage by initially exposing a reduced piston cross-section to combustion gas pressure, followed by full exposure, reducing peak forces and stresses, and eliminating gaps between components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a gas piston system is used to cycle the action in semi-automatic and automatic rifles, then the firearm can automatically extract spent cartridge cases and chamber new rounds, but the system is prone to rattling and wear due to loose fits and physical gaps between components
Solution Approach 1:
The patent applies preliminary action by pre-tensioning the mechanical linkage between the piston and bolt carrier before the piston is fully actuated. The linkage includes a pre-tensioning mechanism that eliminates physical gaps and loose fits between components prior to the piston receiving full gas pressure, thereby preventing rattling and wear during operation
Solution Approach 2:
The patent changes the mechanical state of the linkage from a loose, gap-containing configuration to a pre-tensioned, gap-free configuration. This parameter change in the linkage's mechanical state eliminates the harmful loose fits between piston, transfer rod, and bolt carrier while maintaining the automatic cycling function
2Reliability
If tight tolerances and clearances are maintained for the piston system, then component wear and rattling are reduced, but implementation of quick change barrel system becomes more difficult
Solution Approach 1:
The patent segments the firearm into modular components including a quick-change barrel system, piston assembly, and bolt carrier group. This segmentation allows the barrel to be independently replaced while maintaining tight tolerances in the piston and linkage components, resolving the conflict between reliability and ease of manufacture
3Speed
If full piston cross-section is exposed to full gas pressure immediately, then the piston can rapidly drive the bolt carrier rearward, but high instantaneous forces and stresses are created on the mechanical linkage
Solution Approach 1:
The patent applies preliminary action by first pre-tensioning the mechanical linkage before applying full gas pressure to the piston. This sequence ensures the linkage is ready to handle the full force without excessive stress, while still maintaining rapid piston actuation speed
Solution Approach 2:
The pre-tensioned linkage acts as a cushioning mechanism that prepares the mechanical connection to absorb and distribute the high instantaneous forces from full gas pressure, preventing excessive stress and potential failure of the linkage components
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 approach minimizes component wear, improves reliability, and allows for a quick-change barrel system by maintaining tight tolerances, reducing the impact on the barrel and enhancing the firearm's operational consistency.
Implementation Method 1
A portion of the expanding combustion gases produced by discharging the rifles are ported from the barrel into a cylindrical piston bore containing an axially-movable reciprocating gas piston. The gas acts on the face of the piston driving it abruptly and rapidly rearward.
Data Source
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AI summary
A gas operated autoloading firearm having an improved bolt carrier. The gas piston system may include a barrel defining a longitudinally-extending bullet pathway, a gas block defining a piston bore, a passageway fluidly connecting the bore with the bullet pathway for diverting combustion gas to the bore upon discharging the firearm, and a piston slidably disposed in the bore for reciprocating movement. The piston actuates a reciprocating bolt assembly including a bolt carrier slidably received in a receiver. The bolt carrier includes supporting and guiding surfaces configured to reduce receiver wear and bolt carrier drag.