Tie-Down Reel Embedding Sags for Strap Wear Reduction
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Solution Overview
Problem
Existing ratchet tie down devices cause strap wear and breakage due to friction between the strap and semicylindrical shafts, leading to reduced service life.
Innovation Solution
The tie down device features semicylindrical shafts with arcuate abutments and protrusions that allow the strap to be embedded in embedding sags, preventing displacement and increasing friction resistance, ensuring synchronous rotation with the shafts and reducing wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If smooth curved surfaces are used on semicylindrical shafts for strap winding, then the strap can be easily wound and unwound, but friction between the strap and shafts causes strap wear and breakage
Solution Approach 1:
The invention applies different surface characteristics to different regions of the semicylindrical shafts. The strap contact surfaces are designed with arcuate abutments that have protrusions creating embedding sags, while other surfaces remain smooth. This local differentiation allows the strap to be firmly positioned at critical contact points (reducing wear) while maintaining ease of winding in other areas.
Solution Approach 2:
The protrusions on the arcuate abutments create embedding sags that preliminarily position the strap in a predetermined location before winding begins. This preliminary positioning ensures the strap starts in optimal contact with the shaft, preventing displacement and reducing friction-induced wear during the winding operation.
2Productivity
If the strap is allowed to rotate slightly relative to the semicylindrical shafts during tightening, then the strap can be easily tensioned, but the strap returns to its original position after release causing friction and wear
Solution Approach 1:
The embedding sags created by the protrusions provide localized positioning features at the strap-shaft interface. These localized features prevent the strap from rotating back to its original position after tensioning, while the rest of the winding surface remains smooth to allow easy tightening operations.
Solution Approach 2:
The invention converts the potentially harmful relative rotation and friction into a beneficial self-positioning mechanism. The embedding sags cause the strap to naturally settle into a predetermined position during the tightening process, transforming what would be wear-causing motion into a positioning feature that enhances reliability.
3Reliability
If protrusions with embedding sags are added to the semicylindrical shafts to prevent strap displacement, then strap wear is reduced, but the device structure becomes more complex
Solution Approach 1:
Instead of making the entire semicylindrical shaft complex, the invention only adds protrusions to specific arcuate abutment regions where strap contact occurs. This localized modification maintains the simplicity of the overall reel structure while providing the necessary strap positioning functionality.
Solution Approach 2:
The semicylindrical shaft surface is segmented into distinct functional zones: arcuate abutments with protrusions for strap positioning, and smooth surfaces for easy winding. This segmentation allows each region to perform its specific function optimally without requiring the entire structure to be complex.
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 enhances the strap's service life by minimizing friction and preventing breakage, making the strapping process more efficient and durable.
Implementation Method 1
there will be friction between the strap and the semicylindrical shafts, which will cause the strap to wear
Data Source
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AI summary
The present invention provides a tie down device belonging to the technical field of strapping in transportation. It solves the technical problem that the existing strapping devices can cause the strap to break after a long time of use. The tie down device comprises a bracket, a handle and a reel, the bracket and the handle are pivotally connected through the reel, and the reel is fixed with ratchets. The reel comprises two semicylindrical shafts, a gap is disposed between the two semicylindrical shafts capable of allowing a strap to pass through, away-facing circumferential surfaces of the two semicylindrical shafts are arcuate abutments, each of the abutments has a plurality of protrusions, and between the protrusions is an embedding sag into which the strap is embedded after deformation. The present invention has the advantage of improving the service life of the strap.