Pivoting Bolt Handle Mechanism for Reduced Extraction Force
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Solution Overview
Problem
Conventional bolt mechanisms in manual bolt-action rifles require high extraction forces to dislodge spent cartridges due to sticking issues, which can be challenging and inefficient.
Innovation Solution
A pivoting bolt handle mechanism that leverages the bolt body along the receiver, using a pinned connection to prevent off-axis rotation and apply force in a direction that dislodges the cartridge with reduced friction, allowing for easier extraction of spent cartridges.
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 extraction process becomes complex and requires high force input
Solution Approach 1:
The bolt handle is made pivotable relative to the bolt body, transitioning from a fixed connection to a dynamic connection that allows rotational movement. This enables the handle to apply force in varying directions during the extraction process, improving efficiency while reducing the need for high extraction forces
Solution Approach 2:
The connection between the bolt handle and bolt body is divided into separate components (handle, bolt body, and a connection mechanism allowing relative rotation). This segmentation allows each component to move independently and optimally during operation, simplifying the overall extraction mechanism while maintaining effective force application
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 stuck cartridges
Solution Approach 1:
The fixed connection is replaced with a pivotable connection that allows the handle to rotate relative to the bolt body. This dynamic connection enables the user to apply force more effectively by leveraging the rotational movement of the handle, reducing the extraction force needed while maintaining structural simplicity
3Ease of operation
If conventional fixed bolt handles are used, then the mechanism is straightforward, but cartridge extraction becomes challenging when cartridges are stuck due to expansion
Solution Approach 1:
The pivotable bolt handle allows dynamic adjustment of force application direction during extraction. When cartridges are stuck, the handle can be rotated to apply force at optimal angles, making extraction easier without requiring complex additional mechanisms
Solution Approach 2:
The pivotable handle mechanism allows the bolt assembly to self-adjust and leverage itself during the extraction process. The rotational capability of the handle enables it to automatically find the most effective extraction path, reducing the need for complex external assistance mechanisms
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 handle mechanism reduces the force required for cartridge extraction, enabling efficient and repeated loading, discharge, and unloading of firearms with minimal user effort, even when cartridges are stuck due to expansion.
Implementation Method 1
A pivoting bolt handle mechanism that leverages the bolt body along the receiver
Implementation Method 2
using a pinned connection to prevent off-axis rotation
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.