Tensiometric Device Curvature Design for Rope Stress Reduction
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Solution Overview
Problem
Existing load limiting devices cause excessive deviation angles and unwished tensions in ropes due to small radii of curvature, leading to stretching of elementary wires, which discourages their use in intensive crane operations and fails to meet safety standards.
Innovation Solution
A tensiometric device with a block connected to first and second contrast sectors and a locking clamp, where the ratios of curvature diameters to the rope diameter are greater than 4, specifically between 11.2 and 18, guiding the rope through sections with larger curvatures to prevent bending with small radii and reduce wire stretching, while adhering to safety standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rope is forced to bend with small radii of curvature to achieve deviation in tensiometric devices, then the rope elementary wires are stretched and unwanted tensions are generated, but the device can still measure load effectively
Solution Approach 1:
The invention applies curvature principle by designing contrast sectors with specifically controlled radii of curvature. The first contrast sector has a radius R1 ≥ 10d and the second contrast sector has a radius R2 ≥ 10d (where d is rope diameter), ensuring that the rope bends with adequate curvature radii to avoid wire stretching while still achieving the necessary deviation for measurement. This resolves the contradiction by maintaining measurement functionality while eliminating harmful rope stress through proper geometric design.
2Force
If large deviation angles are imposed on the rope to obtain sufficient horizontal force for measurement, then the force required to deflect the rope becomes negligible, but the rope experiences accentuated bending with small radii of curvature
Solution Approach 1:
The invention changes the geometric parameters of the contrast sectors, specifically setting the radius of curvature R1 and R2 to be at least 10 times the rope diameter d. This parameter change allows the rope to follow a gentler curvature path while still achieving adequate deviation angle for measurement. The force required to deflect the rope remains sufficient for accurate measurement while the rope shape is preserved without excessive bending.
3Measurement precision
If the rope is deflected through multiple curvilinear sections to measure tension, then the measurement function is achieved, but the elementary wires of the rope are stretched due to stress concentration at bend points
Solution Approach 1:
The invention applies curvature principle by designing contrast sectors with specifically controlled radii of curvature. The first contrast sector has a radius R1 ≥ 10d and the second contrast sector has a radius R2 ≥ 10d (where d is rope diameter), ensuring that the rope bends with adequate curvature radii to avoid wire stretching while still achieving the necessary deviation for measurement. This resolves the contradiction by maintaining measurement functionality while eliminating harmful rope stress through proper geometric design.
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 device effectively reduces unwanted tensions and stretching of rope wires by maintaining larger curvatures, ensuring compliance with safety standards and preventing excessive stress on the rope, thus enhancing the reliability and safety of load limiting operations.
Implementation Method 1
The movement of the central pin 108 is contrasted by the action of a stack of cup springs (not represented in Figure 1) which are thus compressed or by the action of another elastic means having the same function.
Implementation Method 2
The rope is therefore deviated by the first contrast sector, the second contrast sector and the locking clamp so as to identify five consecutive sections of rope
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A tensiometric device (10) for load limiting devices, couplable with a rope (8) having a diameter (d) in order to evaluate the tension (T) of the rope and comprising a block (12) on which a first contrast sector (14) and a second contrast sector (16) are connected respectively on the upper part and on the lower part of the block (12). A pin (20) is connected between the first contrast sector (14) and the second contrast sector (16) in the block (12) so as to translate and being coupled to elastic means and to sensor means for the measurement of the translation of the pin (20) on which a locking clamp (18) is fixed. Said rope (8) is deviated by the first contrast sector (14), the second contrast sector (16) and the locking clamp (18).