Straight-Pull Bolt with Oblique Cam for Deformed Cartridge Handling
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Solution Overview
Problem
Existing straight-pull bolt actions for bolt-action rifles are not sufficiently quick or reliable, especially when handling deformed or incorrect cartridges, and require modifications to the barrel.
Innovation Solution
A straight-pull closure system with a rotatably mounted closure sleeve, an obliquely positioned control cam, a connecting link, and a wavy control element that allows the bolt head to be locked and unlocked through a large rotation angle, enabling secure locking and easy ejection of cartridges without barrel modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a classic rotating head bolt is combined with a transmission gear (helix locking principle), then the bolt action can be operated with a straight pull motion, but the operation speed and reliability are insufficient, especially when handling deformed or incorrect cartridges
Solution Approach 1:
The bolt assembly is divided into functionally independent segments: the closure sleeve for locking/unlocking, the control cam for motion conversion, the connecting link for force transmission, and the control element for handling. This segmentation allows each component to be optimized for its specific function, improving overall operation speed and reliability.
Solution Approach 2:
The control cam is designed with an oblique orientation relative to the longitudinal axis, creating a dynamic motion conversion mechanism. As the control element moves linearly, the oblique cam surface converts this motion into rotational movement of the closure sleeve, enabling rapid locking and unlocking actions even with deformed cartridges.
2Reliability
If a control cam extending obliqu to the longitudinal axis is introduced into the closure sleeve, then a large rotation angle is achieved for secure locking, but the device complexity increases
Solution Approach 1:
Multiple functions are merged into the control cam component: it serves as both the motion conversion element (converting linear control element movement to rotational closure sleeve movement) and the locking mechanism (providing the oblique surface for large rotation angle). This consolidation reduces overall device complexity while maintaining secure locking capability.
Solution Approach 2:
The control cam performs multiple functions simultaneously: it converts linear to rotational motion, provides the locking surface for the closure sleeve, and enables the large rotation angle necessary for secure locking. This multi-functionality reduces the need for separate components, simplifying the overall device structure.
3Ease of operation
If a connecting link with a pin engaging the control cam is used, then the rotational movement is effectively transmitted, but the number of components increases
Solution Approach 1:
The pin is integrated directly into the control cam structure, and the connecting link is positioned within the closure sleeve assembly. This nesting arrangement allows the motion transmission components to be compactly housed within existing structural spaces, reducing the overall number of discrete components while maintaining effective motion transmission.
4Productivity
If the closure sleeve is rotatably mounted about the longitudinal axis, then quick operation is achieved, but modifications to the barrel are required
Solution Approach 1:
Instead of modifying the barrel to accommodate a rotating bolt mechanism, the invention inverts the approach by designing the closure sleeve and control cam system to work with the existing barrel structure. The rotatable closure sleeve is mounted independently within the bolt assembly, allowing quick operation without requiring barrel modifications.
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 system provides a quick and reliable operation, ensuring secure locking and easy ejection of cartridges, including tilted ones, with a large rotation angle for secure locking and automatic cocking of the firing pin, and includes a handle lock and safety features for enhanced usability.
Implementation Method 1
A control cam extending obliquely to the longitudinal axis is introduced into the closure sleeve in the region of the rear end
Implementation Method 2
A control cam extending obliquely to the longitudinal axis is introduced into the closure sleeve in the region of the rear end. A pin is arranged at a front end of the connecting link, which is guided along the control cam of the closure sleeve and thereby causes the closure sleeve and the bolt head to rotate
Data Source
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Figure 7
AI summary
The present invention relates to a straight-pull bolt (01) comprising a bolt sleeve (03) rotatably mounted about a longitudinal axis (02) and having a front end at which a bolt head (04) is arranged, and a rear end, wherein a control cam (05) extending obliquely to the longitudinal axis (02) is provided in the inner surface of the bolt sleeve (03) in the region of the rear end. A connecting element (07) extends in the direction of the longitudinal axis (02) with a front end at which a pin (08) engaging with the control cam (05) is arranged, and a rear end, wherein a recess (09) is provided in the region of the rear end. A control cam (12) of a control element (10) engages in the recess (09). A through-opening (13) of the control element (10) serves to guide a firing pin (14).A shaft (15) of the control element (10) extending transversely to the longitudinal axis (02) is connected to a chamber handle (17) for pivoting the control element (10) between an open position and a closed position.