Straight-Pull Bolt Lock With Bevel-Gear Motion Conversion

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Solution Overview

Problem

Existing straight-pull bolt actions for repeating firearms require multiple discontinuous movement segments and are not designed for easy and safe operation, lacking an integrated manual cocking system for the firing pin spring.

Innovation Solution

A straight-pull bolt action mechanism utilizing bevel gears to convert a single continuous motion of the cocking lever into rotational movements of the bolt sleeve and bolt head, incorporating a firing pin spring cocking mechanism that is manually actuated during cartridge change, with a simplified design requiring only two moving parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple discontinuous movement segments are used in straight-pull bolt actions, then the bolt action can achieve locking and unlocking functions, but the operation becomes complex and less reliable

Engineering Contradiction:
Improveoperational reliabilityVSAvoidmovement segments
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple movement segments into a single continuous motion of the cocking lever. The bevel gear mechanism converts this single motion into the necessary rotational movements of the bolt sleeve and bolt head, eliminating the need for multiple separate movement phases and improving operational reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bevel gear acts as an intermediary mechanism that translates the single continuous motion of the cocking lever into the required rotational movements. This intermediary component simplifies the overall motion sequence while maintaining the necessary locking and unlocking functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a single continuous motion is used for the cocking lever, then the operation is simplified and more reliable, but the power transmission becomes less efficient

Engineering Contradiction:
Improveoperation simplicityVSAvoidpower transmission
Core Design Contradiction:
Ease of operationVSPower

Solution Approach 1:

The bevel gear serves as an intermediary that efficiently transmits power from the single continuous motion of the cocking lever to the rotational movements of the bolt sleeve and bolt head. This intermediary mechanism maintains power transmission efficiency while preserving operational simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bevel gear converts the linear continuous motion of the cocking lever into rotational motion, changing the dimension of movement. This dimensional transformation enables efficient power transmission while maintaining the simplicity of the single continuous motion input.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If more moving parts are used in the bolt action, then the locking and unlocking functions can be achieved, but the friction and wear increase

Engineering Contradiction:
Improvelocking functionVSAvoidfriction and wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent merges multiple functions into a reduced number of moving parts. The bevel gear mechanism achieves locking and unlocking functions with fewer components, thereby reducing friction and wear while maintaining reliable operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bevel gear acts as an intermediary that enables the locking and unlocking functions with minimal moving parts. This intermediary mechanism reduces the number of contact points and surfaces subject to friction and wear, improving overall reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 mechanism allows for a single motion conversion with improved power transmission, reduced wear, and enhanced operational reliability, enabling easy and safe operation with fewer parts and less friction.

Implementation Method 1

A first gear component (06) is fixedly mounted to the bolt sleeve (01). The second gear component (08) is positioned at an angle, preferably a right angle, to the first gear component (06). The two gear components are engaged with each other, so that a rotational movement about a first axis transverse to the bore axis can be converted into a rotational movement about a second axis parallel to the bore axis.

Methodology Applied
Scientific EffectGear: Gear

Data Source

PatentEP3978859B1Straight pull bolt lock for repeating weapons and repeating weapon with the same
Publication Date: 2025.11.05 MERKEL JAGD & SPORTWAFFEN
  • EP3978859B1 patent drawingFigure 1
  • EP3978859B1 patent drawingFigure 2
  • EP3978859B1 patent drawingFigure 3

AI summary

The present invention relates to a straight-pull bolt action for repeating firearms, comprising a bolt sleeve (01) rotatable about a longitudinal axis (02), a first gear component (06), a second gear component (08), and a cocking lever (09). At its front end, the bolt sleeve (01) has a bolt head (03) fixedly arranged to prevent rotation. The first gear component (06) is fixedly attached to the rear end of the bolt sleeve (01), such that when the first gear component (06) rotates, the bolt sleeve (01) rotates with it. The second gear component (08) is oriented at an angle to the first gear component (06) and engages with it to mechanically transmit a rotary motion. The cocking lever (09) is connected to the second gear component (08) so that the cocking lever (09) is rotatable with it, and the cocking lever (09) can be locked into at least two functional positions (A, C).Furthermore, the repeating lever (09), together with the two gear components (06, 08) and the locking sleeve (01), is movable forwards and backwards in the axial direction. The invention further relates to a repeating weapon with such a straight-pull locking mechanism.