Wider Sheave Rigging Block for Synthetic Roundsling Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art rigging blocks designed for wire rope are not well suited for synthetic roundslings, which have a flatter cross-section, leading to issues like the roundsling doubling over during off-center lifting operations, as they fail to maintain the wider cross-section and provide adequate lateral stability.
Innovation Solution
A rigging block with a wider sheave and angled side sections forming a channel to hold the synthetic roundsling, combined with a plurality of bearings along the sheave axis for enhanced stability and load equalization, and the sheave can be made from synthetic materials like plastic to reduce wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional wire rope rigging block is used with a synthetic roundsling, then the rigging block structure remains simple, but the synthetic roundsling doubles over and loses lateral stability due to its wider cross-section
Solution Approach 1:
The sheave is designed with non-uniform geometry, featuring a wider channel and higher side sections specifically at the locations where the synthetic roundsling contacts the sheave. This local modification provides the necessary lateral containment for the wider cross-section roundsling without requiring complete redesign of the entire sheave structure.
Solution Approach 2:
The sheave incorporates asymmetric features with higher side sections that create a channel tailored to the specific geometry of synthetic roundslings. This asymmetric design contrasts with traditional symmetric wire rope sheaves and provides the lateral stability needed to prevent the roundsling from doubling over during off-center lifting operations.
2Strength
If a steel sheave is used, then the sheave provides high strength and durability, but it causes increased wear and tear on the synthetic roundsling
Solution Approach 1:
The material of the sheave is changed from steel to plastic, fundamentally altering the friction characteristics and surface properties. This parameter change reduces the harmful wear effect on the synthetic roundsling while the plastic material is engineered to maintain sufficient structural strength for the application.
Solution Approach 2:
The sheave is manufactured from plastic material, which can be considered a composite or engineered material that combines the necessary strength properties with reduced friction and wear characteristics compared to traditional steel, thereby protecting the synthetic roundsling.
3Area of stationary object
If the sheave width is increased to accommodate the wider synthetic roundsling cross-section, then the roundsling is properly supported, but the rigging block size and weight increase
Solution Approach 1:
The sheave channel width and side section height are increased to specific dimensions that accommodate the wider cross-section of synthetic roundslings. These parameter changes provide proper lateral support without excessive increase in overall rigging block size, balancing support requirements with size constraints.
Data Source
AI summary
An equalizing rigging block for use with a synthetic roundsling is disclosed. The rigging block includes in preferred embodiments (a) a flatter and wider sheave to better accommodate a wider or flatter cross-section synthetic roundsling; (b) higher side sections for the sheave; and (c) a plurality of stacked bearings along the rigging block axis to provide enhanced lateral stability of the rigging block. In preferred embodiments, the rigging block sheave is manufactured from a synthetic material, such as plastic. The equalizing rigging block exhibits improved characteristics of holding a synthetic roundsling within the rigging block, and of reducing wear and tear on the roundsling.