Interlocking Solid Stick Curved Nib Vibration Resistance

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Solution Overview

Problem

Existing interlocking solid composition sticks for steel surfaces in sliding or rolling-sliding contact fail due to high vibration and shock, leading to premature failure and frequent replacement, as well as potential jamming and damage in rail systems.

Innovation Solution

A modified interlocking solid composition stick with a block and nib design featuring curved or straight side edges, a specific length ratio, and a tapered nib, which reduces stress concentrations and enhances resistance to failure by optimizing the dimensions of the cavity and nib to distribute loads more evenly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If interlocking solid composition sticks are used for steel surfaces in sliding contact, then friction control is achieved, but the sticks fail due to high vibration and shock conditions

Engineering Contradiction:
Improvestick durabilityVSAvoidvibration and shock
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies curvature to the nib portion of the stick, changing it from a sharp angular shape to a rounded contour. This curvature redistributes stress concentrations that occur during vibration and shock, preventing catastrophic failure at corner points and extending the operational life of the stick under harsh rail system conditions.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent modifies the geometric parameters of the stick, specifically the ratio between the nib length and the overall stick length, and the angular parameters of the nib contour. These parameter changes optimize the stress distribution and mechanical properties of the stick, enabling it to withstand the high vibration and shock environments of rail systems while maintaining its friction control function.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the cavity and nib dimensions are not optimized, then manufacturing is simpler, but stress concentrations cause premature failure at the cavity end

Engineering Contradiction:
Improvefailure resistanceVSAvoidcavity and nib design complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent specifies optimized parameter ranges for the nib and cavity dimensions, including the length ratio and angular contours. These parameter changes are designed to eliminate stress concentrations at the cavity end while remaining compatible with standard manufacturing processes, thus improving reliability without significantly increasing manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the stick design does not account for stress distribution, then design is simpler, but high stresses at cavity corners lead to frequent replacement

Engineering Contradiction:
Improveapplication longevityVSAvoidstick geometry
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

By rounding the nib contour and optimizing its geometric parameters, the patent eliminates sharp corners that act as stress concentration points. This geometric optimization extends the service life of the stick, reducing replacement frequency and improving overall system productivity without requiring complex additional components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent optimizes the geometric parameters of the stick, including the nib length-to-stick length ratio and the angular contours of the nib. These parameter changes are designed to distribute stresses evenly throughout the stick structure, preventing premature failure and extending application longevity while maintaining a relatively simple overall design.

Inventive Principle:
Principle #35Parameter changes

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 modified stick design significantly increases resistance to failure from vibration and shock, reducing the need for frequent replacements and minimizing the risk of jamming, thereby improving the operational efficiency and longevity of rail systems.

Implementation Method 1

The internal wall of the cavity has approximately the same dimensions as the outer surface of the nib, such that a nib of one stick can snugly fit into the cavity of a second stick

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Implementation Method 2

The nib member of the interlocking solid stick of the present invention preferably tapers away from the body member at an angle of taper. The angle of taper is preferably from about 7.0 to about 10.0 degrees

Methodology Applied
Scientific EffectPressure distribution: Mechanical Force

Data Source

PatentEP1880136B8Modified interlocking solid stick
Publication Date: 2012.09.26 L B FOSTER RAIL TECHNOLOGIES CORP

AI summary

The present invention provides a modified interlocking solid composition stick for applying to steel surfaces that are in sliding or rolling-sliding contact. The modified stick comprises a body member with four sides, a first end and an opposed second end, and a nib member attached to the first end of the body member, the nib member having four sides connected by substantially curved side edges. The second end of the body member contains a cavity with substantially curved side walls dimensioned to snugly receive a nib member of a corresponding interlocking solid stick. To reduce the likelihood of failure of the nib or cavity, the dimensions of the nib are optimized such that a length of one side of the nib member (nl) and a length of the side of the body member (l) in the same plane has a ratio nl/l from about 0.6 to about 0.75.