Segmented Control Cam for Jam-Resistant Handgun Bolt

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Solution Overview

Problem

Self-loading handguns often experience issues with sand, dust, and mud accumulation, leading to jamming and reduced propellant effectiveness due to oil contamination, which can result in 'floppy shots' under adverse conditions.

Innovation Solution

The locking mechanism is enhanced by dividing the unlocking control edge into three sections with increasing angles of inclination, utilizing residual gas pressure to accelerate the bolt carrier, and incorporating a U-shaped design to secure the control bolt, ensuring efficient unlocking and reloading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the handgun is kept ready to fire for extended periods without cleaning, then operational readiness is improved, but sand, dust, and mud accumulate in the mechanism causing malfunctions

Engineering Contradiction:
Improveoperational readinessVSAvoidmechanism reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control cam is divided into multiple edge sections (first, second, third unlocking edge sections and fourth, fifth locking edge sections) with different functions. Each section handles a specific phase of the bolt head rotation, distributing the unlocking and locking tasks across segmented functional zones to improve overall system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control cam edges are designed with varying angles of inclination that change dynamically during the bolt carrier's recoil movement. The angle increases from the first to the third unlocking edge section, creating a progressive rotational acceleration that adapts to the changing energy conditions during the self-loading process.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the barrel is heavily oiled to prevent contamination, then protection against sand and dust is improved, but oil can enter the cartridge and render propellant ineffective

Engineering Contradiction:
Improveprotection against contaminationVSAvoidpropellant effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

Different parts of the control cam have different geometric properties. The first unlocking edge section has a shallow angle for smooth engagement, while subsequent sections have steeper angles for accelerated rotation. This local differentiation of geometric quality optimizes performance at each stage of the unlocking process.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the bolt carrier recoils slowly due to accumulated impurities, then the weapon can be operated, but the recoiling bolt is slowed down too much causing malfunctions

Engineering Contradiction:
Improvebolt carrier movementVSAvoidreloading mechanism function
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The angle of inclination of the control cam edges is changed as a parameter to optimize the unlocking process. The angles increase progressively from the first to the third unlocking edge section, transforming the energy transfer characteristics to ensure reliable bolt head rotation even when the bolt carrier's recoil speed is reduced by contamination.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If a simple locking control system is used, then manufacturing is easier, but the system may not be well adapted to energy conditions during self-loading

Engineering Contradiction:
Improvecontrol system manufacturingVSAvoidenergy adaptation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The control cam edges are designed with varying angles of inclination that create dynamic rotational acceleration of the bolt head. This dynamic design adapts to the changing energy conditions during the self-loading process, ensuring reliable operation without requiring complex additional mechanisms.

Inventive Principle:
Principle #15Dynamics

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

This solution optimizes the unlocking process, reducing jamming and maintaining firing accuracy even under dirty conditions, with improved energy transfer and reduced friction, allowing for reliable operation in harsh environments.

Implementation Method 1

a residual gas pressure, harmless to safety, remains in the chamber and barrel. This residual gas pressure further accelerates the cartridge case, which has ejected from the chamber, along with the already recoiling bolt head and control bolt, backwards.

Methodology Applied
Scientific EffectGas pressure: Pressure Gradient

Data Source

PatentEP3372942B1Lockable self-loading handgun
Publication Date: 2020.04.29 HECKLER & KOCH GMBH
  • EP3372942B1 patent drawingFigure 1~2
  • EP3372942B1 patent drawingFigure 3
  • EP3372942B1 patent drawingFigure 4a~4b

AI summary

Lockable and unlockable self-loading handgun with a reciprocating bolt carrier (18) having a control cam (40) into which a control pin (36) fixedly connected to a bolt head (20) engages, wherein: - a release control edge (50) of the control cam (40) is essentially composed of two intersecting straight edge sections (52, 54) of different inclinations (α, β) and a subsequent curved third edge section (56) of even greater inclination; - a locking control edge (60) of the control cam (40) is essentially composed of two edge sections (62, 64) which run parallel to the straight edge sections of the release control edge (50); and - the control cam has at its release-side end a circular arc-shaped edge section (70) whose longitudinally elongated (Δd) longitudinal diameter is longer than the The diameter of the control bolt (36) is (Fig. 10).