Bolt Catch Assembly for Multi-Magazine Last-Round Hold Open
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Solution Overview
Problem
Existing bolt catches in semiautomatic firearms are typically configured to engage only one type of magazine, limiting their adaptability to different magazine designs.
Innovation Solution
A bolt catch assembly with a follower transfer adapter and linkage system that allows the bolt catch to be adapted for different magazine types, utilizing a pivotable follower transfer adapter and levers to transfer rotational movement to the bolt catch, enabling it to hold the bolt open after the last cartridge is fired.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the bolt catch is configured for engagement with only one type of magazine, then the structure is simple and reliable, but the adaptability to different magazine designs is limited
Solution Approach 1:
The bolt catch system is segmented into a main bolt catch component and a separate follower transfer adapter. The adapter can be removed and replaced depending on the magazine type being used, allowing the main bolt catch structure to remain simple while the adapter provides the necessary adaptability for different magazine designs.
Solution Approach 2:
The follower transfer adapter serves multiple functions: it adapts the bolt catch to work with different magazine types, transfers the follower's movement to the bolt catch, and can be configured with different engagement portions for various magazine designs. This single component provides universal compatibility across multiple magazine types.
2Adaptability or versatility
If a follower transfer adapter and linkage system are added to adapt the bolt catch for different magazines, then the adaptability improves, but the device complexity increases
Solution Approach 1:
The follower transfer adapter acts as an intermediary component between the magazine follower and the bolt catch. It receives movement from the follower and transfers it through a linkage system to actuate the bolt catch, enabling compatibility with different magazine types without modifying the main bolt catch structure.
Solution Approach 2:
The follower transfer adapter is designed to be pivotable and removable, allowing it to dynamically adapt to different magazine configurations. The linkage system includes movable levers that transfer rotational movement, providing flexible adaptation while maintaining a relatively simple overall structure.
3Reliability
If the bolt catch is held out of battery after the last cartridge is expended, then the shooter is immediately alerted to reload, but the mechanism requires precise engagement with the follower
Solution Approach 1:
The follower transfer adapter is pre-configured with engagement portions that are designed to engage the magazine follower at specific points during the feeding cycle. This preliminary configuration ensures reliable engagement and consistent bolt hold-open operation without requiring complex adjustment mechanisms.
Solution Approach 2:
The engagement mechanism is designed to automatically engage the follower and trigger the bolt catch during normal magazine operation. The follower's own movement during cartridge feeding serves to actuate the adapter and linkage system, which in turn activates the bolt catch without requiring additional power or complex control mechanisms.
Data Source
AI summary
An assembly for holding a bolt of a firearm in an open position is disclosed. The assembly comprises a bolt catch pivotable about a first axis toward and away from a catching position. In the catching position, a portion of the bolt catch is within a path of travel of the bolt. A follower transfer adapter is pivotable about a second axis. The follower transfer adapter includes an engagement portion that is configured to engage a follower of a magazine. Optionally, the follower transfer adapter includes an overhang lip that extends transversely to the longitudinal axis of the firearm and into a path of travel of the follower to define the engagement portion. The engagement portion is positioned between the second axis and the bolt catch along the longitudinal axis of the firearm. A linkage transfers rotational movement of the follower transfer adapter to rotation of the bolt catch.