Yieldable Mine Prop With Insert For Dynamic Load Management

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Solution Overview

Problem

Conventional mine roof supports, such as sand props, tend to buckle and fail after limited displacement under load, failing to effectively manage dynamic loads in underground mining environments.

Innovation Solution

A mine prop design featuring a yieldable insert and particulate matter, where the yield member is configured to yield before the pipes, allowing for increased displacement and load-bearing capacity by transitioning particulate matter from one pipe to another as the prop extends, with a secondary yielding arrangement providing additional vertical displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sand props are used with telescoping pipes, then the prop can support mine roof loads, but the prop buckles and fails after limited displacement (1.5-2 inches)

Engineering Contradiction:
Improveload-bearing reliabilityVSAvoiddisplacement capacity
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The prop is divided into multiple functional segments: outer pipe, inner pipe, yieldable insert, and particulate matter. Each segment serves a specific function - the yieldable insert yields at a predetermined load to enable displacement, while the particulate matter flows to maintain support. This segmentation allows the system to achieve both reliability and extended displacement capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The yieldable insert changes its mechanical properties based on applied load - remaining rigid below the yield load and becoming deformable above it. This parameter change allows the prop to transition from a rigid support structure to a yieldable mechanism that accommodates roof movement while maintaining load-bearing capacity.

Inventive Principle:
Principle #35Parameter changes

2Length of moving object

If the prop is designed to yield under load, then displacement capacity increases, but load-bearing capacity may be compromised

Engineering Contradiction:
Improvedisplacement capacityVSAvoidload-bearing capacity
Core Design Contradiction:
Length of moving objectVSStrength

Solution Approach 1:

The particulate matter acts as an intermediary between the yielding insert and the support function. As the yieldable insert deforms, the particulate matter flows from the inner pipe through the insert into the outer pipe, maintaining continuous load-bearing capacity throughout the displacement process. This mediator ensures that yielding does not compromise overall strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The particulate matter is pre-positioned in the inner pipe before installation. When the prop extends and the yieldable insert deforms, the particulate matter automatically flows into position to provide continuous support. This preliminary positioning ensures that load-bearing capacity is maintained without requiring active intervention during the yielding process.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a yieldable insert is added to the prop design, then displacement and load management improve, but device complexity increases

Engineering Contradiction:
Improveload management capabilityVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The yieldable insert functions as a flexible element that deforms under load to enable displacement. This flexible component is integrated into the telescoping pipe structure, allowing the prop to accommodate roof movement while maintaining a relatively simple overall structure. The insert's flexibility provides the necessary yielding capability without requiring complex mechanical systems.

Inventive Principle:
Principle #30Flexible shells and thin films

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 design enhances the mine prop's ability to maintain load-bearing capacity under dynamic conditions, offering increased displacement and load management compared to conventional props, which typically fail after 1.5-2 inches of displacement.

Implementation Method 1

The yield member is configured to yield before the first and second pipes when the mine prop is placed under a predetermined load

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The first end of the body of the yield member may define an annular recess with the first end of the body of the yield member secured to the second end of the second pipe via a friction fit

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentUS9995140B2Yieldable prop with yieldable insert
Publication Date: 2018.06.12 FCI HOLDINGS DELAWARE LLC

AI summary

A mine prop includes a first pipe having a first end and a second end, a second pipe having a first end and a second end, and a yield member secured to the second pipe. The second pipe is slidably received in the first pipe. The yield member is configured to yield before the first and second pipes when the mine prop is placed under a predetermined load.