Firearm Bolt Head Locking Mechanism with Eccentric Intermediate Piece
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Solution Overview
Problem
Existing locking devices for firearms, particularly bolt-action rifles, face issues with secure and reliable locking mechanisms due to limited rotation angles and unreliable expandable sleeves, which hinder effective handling and rapid operation.
Innovation Solution
A breech design featuring a rotatable bolt head connected via an intermediate piece to the bolt lever, allowing for a large longitudinal stroke and corresponding angle of rotation, secured by a spring-loaded locking bolt and rocker mechanism, enabling secure locking and easy disassembly without tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If locking is done via balls pressed outwards against the inner wall of the breechblock, then the bolt lever can be positioned favorably at the rear, but the locking mechanism is unreliable in practice
Solution Approach 1:
The patent introduces an intermediate piece (Stück 17) that mediates between the control piece and the bolt lever. This intermediate piece with its offset articulation point transforms the limited control piece stroke into a larger bolt lever rotation angle, achieving reliable locking while maintaining favorable bolt lever positioning.
2Device complexity
If the control piece has a short stroke of about 8-10 mm, then the design is simple, but only limited rotation angles of up to about 20° are achieved which is insufficient for secure locking
Solution Approach 1:
The patent solves the stroke limitation by changing the dimension of motion transformation. The intermediate piece converts the linear stroke of the control piece into a rotational motion of the bolt lever with larger angle, effectively multiplying the motion effect without increasing the control piece stroke length.
Solution Approach 2:
The intermediate piece acts as a motion amplifier mediator. Its offset articulation geometry transforms the small linear displacement of the control piece into a larger angular displacement of the bolt lever, achieving secure locking with limited control piece travel.
3Device complexity
If an expandable sleeve is used for locking, then the structure is simple, but the locking is not always reliable
Solution Approach 1:
The intermediate piece serves as a reliable mechanical mediator that ensures positive engagement between the control piece and bolt lever. This intermediary mechanism provides dependable locking through geometric constraint rather than relying on expandable sleeve friction or deformation.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a locking device for firearms, in particular for repeating rifles, comprising a cartridge chamber, an external sleeve (1) and a chamber (3) received therein, wherein the chamber (3) has a locking head (2) in the area facing the cartridge chamber and a control piece (4) is axially displaceable within the chamber (3) relative to the chamber (3) and relative to the locking head (2), further comprising a locking lever (6) which is connected to the control piece (4) so that the locking head (2) is unlocked during a backward movement of the locking lever (6) and locked during its continued movement, wherein the locking lever (6) is pivotably mounted in the rear end region of the sleeve (1) and the locking lever is pivotably mounted about an axis which is eccentric to the longitudinal axis of the chamber (3), wherein, according to the invention, the control piece (4) is connected to the locking lever (6) via an intermediate piece (17).which projects radially outwards from the chamber, and wherein the locking head (2) is rotatably mounted in the chamber (3) about its axis (13) and the locking head (2) is rotated by axially displacing the control piece (4).