Breech Plug Gas Seal for Muzzle Loading Rifle Thread Protection

Solution Overview

Problem

Muzzle loading rifles face issues with breech plug removal due to fouling, which requires excessive torque as gases and particles clog the threads, making it difficult to remove the plug for cleaning.

Innovation Solution

A breech plug with a seal element, such as piston rings or a cup, is used to protect the threads from gas and debris, and a hexagonal profile for easy removal, along with a design that reduces friction and wear by allowing the rings to shift axially, providing a strong seal and facilitating easy installation and removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a finely threaded breech plug is used to secure the plug in place, then safety against hang fires is improved, but thread fouling occurs causing excessive torque requirement for removal

Engineering Contradiction:

Improvesafety against hang firesVSAvoidease of removal for cleaning

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The breech plug is divided into two functional zones: a smooth bore section that interfaces with the barrel bore and prevents fouling, and a threaded section that provides secure attachment. This segmentation allows the threaded portion to remain protected from gas and particulate contamination while still providing reliable engagement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A seal element acts as an intermediary between the barrel bore and the threaded section of the breech plug. This seal element prevents gases and particles from accessing the threads during firing, thereby preventing fouling while maintaining the secure engagement provided by the threads.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If multiple thread turns are used to secure the plug, then safety is improved, but the number of rotations required for removal increases torque requirement

Engineering Contradiction:

Improvesafety against hang firesVSAvoidtorque to remove plug

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The breech plug is divided into two functional zones: a smooth bore section that interfaces with the barrel bore and prevents fouling, and a threaded section that provides secure attachment. This segmentation allows the threaded portion to remain protected from gas and particulate contamination while still providing reliable engagement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A seal element acts as an intermediary between the barrel bore and the threaded section of the breech plug. This seal element prevents gases and particles from accessing the threads during firing, thereby preventing fouling while maintaining the secure engagement provided by the threads.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Strength

If threads are exposed to gases and particles during firing, then secure attachment is achieved, but fouling clogs the threads

Engineering Contradiction:

Improveattachment strengthVSAvoidthread fouling

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The breech plug is divided into two functional zones: a smooth bore section that interfaces with the barrel bore and prevents fouling, and a threaded section that provides secure attachment. This segmentation allows the threaded portion to remain protected from gas and particulate contamination while still providing reliable engagement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A seal element acts as an intermediary between the barrel bore and the threaded section of the breech plug. This seal element prevents gases and particles from accessing the threads during firing, thereby preventing fouling while maintaining the secure engagement provided by the threads.

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 solution effectively prevents thread fouling, reduces the effort required to remove the breech plug, and ensures a reliable seal against gases, enhancing the maintenance and operation of muzzle loading firearms.

Implementation Method 1

A breech plug is removably attached to the barrel. The breech plug including a seal element closely received by the bore. The seal element may be a set of piston rings that are received in a circumferential groove about a forward end of the plug, or may be a cup at the forward end, with a forward rim that flares under pressure to provide a gas seal.

Methodology Applied

Scientific EffectGas seal:

Implementation Method 2

a cup at the forward end, with a forward rim that flares under pressure to provide a gas seal

Methodology Applied

Scientific EffectPressure-induced flaring: Pressure Increase

Data Source

PatentUS7814694B2Muzzle loading rifle with breech plug having gas seal facility

Publication Date: 2010.10.19 TCA IP LLC

AI summary

A muzzle loading firearm has a barrel with a bore on a bore axis, and the barrel has a muzzle end and a breech end. A frame is connected to the barrel, and has a breech face. The frame moves between an open position in which the breech face is away from the breech end of the barrel, and a closed position in which the breech face abuts the breech end of the barrel. A breech plug is removably attached to the barrel. The breech plug including a seal element closely received by the bore. The seal element may be a set of piston rings that are received in a circumferential groove about a forward end of the plug, or may be a cup at the forward end, with a forward rim that flares under pressure to provide a gas seal.