Rotating Extractor Cam Mechanism for Firearm Slide Friction
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Solution Overview
Problem
Modern auto-loading pistols face friction issues due to the necessary biasing force on the extractor hook, which slows the slide movement to battery and inhibits reliable cartridge extraction.
Innovation Solution
The extractor design incorporates a cam follower system with angularly oriented surfaces and a dual spring mechanism that allows the hook to engage and disengage from the cartridge rim efficiently, reducing friction and maintaining reliable extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the extractor hook is spring biased to engage the cartridge rim with significant force, then reliable cartridge extraction is ensured, but friction between the hook and cartridge increases which slows slide movement to battery
Solution Approach 1:
The extractor body is made movable relative to the slide along the longitudinal axis, allowing it to dynamically adjust its position. The cam follower mechanism enables the extractor to move forward during extraction to maintain engagement, then retract during closure to reduce friction, solving the contradiction between maintaining extraction reliability and enabling rapid slide closure
Solution Approach 2:
The cam follower acts as an intermediary mechanism between the spring bias and the hook engagement. It translates the spring force into controlled extractor body movement, allowing the hook to engage the cartridge rim reliably during extraction while minimizing contact during the closure phase, thus resolving the friction-speed contradiction
2Reliability
If the extractor hook engages the cartridge rim with significant force, then the hook prevents pivoting outwardly during extraction, but this causes the hook to drag across the rim generating friction
Solution Approach 1:
The extractor body dynamically changes its engagement state with the cartridge rim. During extraction, the cam follower maintains forward pressure to ensure reliable engagement. During closure, the extractor body retracts, reducing contact between the hook and rim, thereby minimizing friction while maintaining extraction reliability when needed
Solution Approach 2:
The extractor body undergoes periodic movement - advancing during extraction to maintain engagement force, then retracting during closure to minimize friction. This periodic action allows the system to alternate between high engagement force and low friction states, resolving the contradiction
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 design reduces friction between the hook and cartridge, facilitating smoother slide movement and improving ammunition feeding reliability by allowing a larger flag distance and enabling the hook to snap over the rim effectively during closure.
Implementation Method 1
A first spring acts between the slide and the extractor body for biasing the extractor body into engagement with the first cam
Implementation Method 2
The first cam follower is engageable with the first cam. The cam surface may be angularly oriented with respect to the longitudinal axis by way of example. The cam surface may have an orientation angle of about 45° relatively to the longitudinal axis
Data Source
AI summary
An extractor is mounted on a slide of an auto-loading firearm. The extractor is capable of rotational and translational motion relative to the slide resulting in improved functioning through an increase in flag distance and reduced friction between the extractor and cartridge when the slide moves into battery. The extractor has a cam follower which cooperates with a cam on the slide to maintain the extractor hook in engagement with the rim of the cartridge during extraction. The extractor is biased into engagement with the cam, and a second cam follower on the extractor is engageable with the barrel face when the slide moves into battery.