Firearm Bolt Assembly with Pivoting Handle for Low-Force Extraction
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Solution Overview
Problem
Conventional bolt mechanisms in manual bolt-action rifles often require high extraction forces to dislodge spent cartridges due to the expansion of cartridge bodies, which can stick to the chamber sidewalls, necessitating complex helical extraction cams.
Innovation Solution
A pivoting bolt handle mechanism that leverages a pinned-connection to limit bolt body rotation, allowing the bolt to be translated along the receiver with minimal user-applied force, utilizing mechanical advantage to dislodge cartridges efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a helical extraction cam is used to generate high extraction forces, then spent cartridges can be dislodged from the chamber, but the device complexity increases and the mechanism becomes less reliable
Solution Approach 1:
The extraction function is segmented from the main bolt rotation function. The bolt handle is divided into a rotation portion for locking/unlocking and a pivoting extraction portion for cartridge removal. This allows the extraction mechanism to be simpler and more reliable while still generating sufficient extraction force through the pivoting motion that leverages the bolt body against the receiver.
2Device complexity
If the bolt handle is fixedly connected to the bolt body, then the structure is simple, but high extraction forces are required to dislodge spent cartridges
Solution Approach 1:
The bolt handle connection transitions from a fixed rigid connection to a dynamic pivoting connection. The handle pivots on a pivot pin that allows rotational movement during extraction, enabling the user to apply force more effectively. This dynamic connection multiplies the user's extraction effort through leverage, reducing the direct force requirement while maintaining structural simplicity.
3Ease of operation
If the bolt body is rotated to extract cartridges, then extraction can be achieved, but the bolt body rotation is limited and requires additional extraction force
Solution Approach 1:
The pivot pin acts as an intermediary element between the bolt handle and bolt body. It mediates the force transmission by allowing the handle to pivot independently while still connected to the bolt body. This intermediary mechanism enables smoother, more effective extraction with reduced force requirements compared to direct rigid connection or limited rotation alone.
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
The pivoting bolt handle system reduces the required extraction force, enabling easy and efficient removal of spent cartridges with minimal user effort, improving operational ease and reliability.
Implementation Method 1
A pivoting bolt handle mechanism that leverages a pinned-connection to limit bolt body rotation, allowing the bolt to be translated along the receiver with minimal user-applied force, utilizing mechanical advantage to dislodge cartridges efficiently.
Data Source
AI summary
Firearms and bolt mechanisms are disclosed herein. The firearm can include a bolt assembly configured to provide leverage for extracting a cartridge. The bolt body can include a main cylindrical body, handle, and a pivot pin extending through a portion of the handle within the cylindrical body. The handle can be rotated relative to the main cylindrical body to push the bolt assembly along an internal passageway of the receiver.