Crane Boom Rail With Resilient Web Member
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Solution Overview
Problem
Current rail assemblies for cranes with pivoting booms face issues with shock absorption and alignment problems at the rail discontinuity, leading to premature wear and maintenance challenges due to high impact loads and alignment errors.
Innovation Solution
A rail design with a resilient member integrated across the web of the rail, providing resiliency between the rail head and foot, acts as a shock absorber to dissipate energy from passing wheels, reducing stress on fasteners and allowing for firm clamping while maintaining flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the rail is clamped rigidly to withstand longitudinal shock forces, then the rail can resist high impact loads, but the fasteners are subjected to increased stress leading to loosening and fatigue
Solution Approach 1:
The rail is divided into two distinct sections: a rigid clamping section for withstanding longitudinal shock forces, and a flexible section with a resilient member embedded in the web to accommodate vertical misalignment and reduce stress on fasteners. This segmentation allows each part to perform its specific function optimally.
Solution Approach 2:
Different portions of the rail are given different mechanical properties. The region near the discontinuity incorporates a resilient member providing local flexibility and shock absorption, while other regions maintain rigid clamping for structural stability. This local differentiation resolves the contradiction between overall rigidity and localized flexibility.
2Adaptability or versatility
If soft mounting with rail pad and clips is used to allow vertical movement, then the rail can adjust to wheel movement, but it cannot withstand longitudinal shock forces at the discontinuity
Solution Approach 1:
The rail assembly is segmented into a flexible mounting section using traditional soft mounting (rail pad and clips) that allows vertical adjustment, and a rigid clamping section that provides longitudinal strength. The resilient member further divides the flexible section into zones with different degrees of flexibility.
Solution Approach 2:
Soft mounting with vertical adjustment capability is applied locally at sections where wheel movement accommodation is needed, while rigid clamping is applied at sections requiring longitudinal shock resistance. The resilient member creates a gradient of flexibility along the rail length.
3Object-affected harmful factors
If the rail discontinuity is made progressive (oblique or L-shaped) to reduce shock, then the load transition is smoothed, but alignment errors still occur over time due to hinge play and wear
Solution Approach 1:
The resilient member is embedded in advance in the web of the rail at the discontinuity, providing pre-positioned shock absorption and alignment tolerance. This beforehand cushioning compensates for future alignment errors caused by hinge play and wear, maintaining smooth load transition over time.
Solution Approach 2:
The resilient member acts as an intermediary element between the rigid rail sections, absorbing misalignment and shock forces that would otherwise be transmitted directly through the discontinuity. This mediator protects the progressive discontinuity shape from degradation due to wear and play.
4Force
If a continuous band of soft rubber (rail pad) is used for mounting, then the rail can absorb vertical shocks, but it cannot provide sufficient lateral restraint and longitudinal strength
Solution Approach 1:
The mounting system is segmented into soft rubber rail pads for vertical shock absorption, metal clips for lateral restraint, and a resilient member embedded in the rail web for longitudinal flexibility and shock resistance. Each component handles a specific directional force.
Solution Approach 2:
The rail assembly combines multiple materials with different properties: soft rubber for vertical compliance, metal for lateral strength and rigidity, and a resilient composite material embedded in the web for longitudinal shock absorption. This composite approach achieves multi-directional performance.
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 design extends the lifetime of rail assemblies, reduces maintenance needs, and minimizes the risk of fastener loosening and fatigue, enabling longer operational periods with reduced crane immobilization.
Implementation Method 1
A rail design with a resilient member integrated across the web of the rail, providing resiliency between the rail head and foot, acts as a shock absorber to dissipate energy from passing wheels
Data Source
AI summary
Rail (10, 30) for use at boom hinges (5) of a crane (1), extending longitudinally from one end (11) to an opposite end (12), comprising a rail head (13, 33) having a running surface (131) for a wheel of a railway vehicle, a rail foot (14, 18, 38) for fastening the rail, and a web (15) connecting the rail head to the rail foot and interposed between the rail head and the rail foot, wherein the rail head is continuous along the length of the rail. The rail comprises a resilient member (16, 36) extending across the web (15) from the one end (11) of the rail over a length shorter than the length of the rail in order to provide a resiliency of the rail head (13, 33) relative to the rail foot (18, 38) over a length of extension of the resilient member.