Weighbridge Levers for High-Resolution Load Measurement
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Solution Overview
Problem
Precision balances face challenges in achieving high load-bearing capacity with high resolution and metrological precision while maintaining a compact design, as existing systems are limited by corner load and torque sensitivity, and the complexity of monolithic multiple transmissions.
Innovation Solution
The design employs a weighing bridge with multiple separate levers that distribute the total weight force across at least four levers, reducing stress on individual mechanisms and allowing for a compact, narrow structure with free space for other components, using a force transducer for precise measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single transmission system is used in monolithic load cells, then the structure is simple and compact, but the measuring range is limited to about 30 kg
Solution Approach 1:
The patent divides the single transmission system into multiple separate transmission stages (first transmission stage with lever ratio 1:2, second transmission stage with lever ratio 1:2, and third transmission stage with lever ratio 1:1.5). Each stage handles a portion of the total weight force, allowing the system to measure loads up to 60 kg while maintaining manageable stress levels in each individual transmission mechanism.
2Weight of moving object
If the transmission ratio of the lever mechanism is increased to extend measuring range, then the load-bearing capacity increases, but the resolution of the measuring system decreases
Solution Approach 1:
Instead of using a single high-ratio transmission, the patent segments the transmission into multiple stages with moderate individual ratios (1:2, 1:2, 1:1.5). The cumulative effect achieves the required load-bearing capacity while each stage maintains sufficient resolution. The separate handling of weight force components in each stage preserves measurement precision.
Solution Approach 2:
The patent introduces a vertical dimension by stacking transmission stages vertically rather than horizontally. This allows multiple transmission mechanisms to be arranged in space without increasing the horizontal footprint, enabling higher load capacity while maintaining compact design and measurement resolution.
3Weight of moving object
If multiple transmissions are used to extend measuring range, then the load-bearing capacity increases, but the production complexity increases and space requirements increase
Solution Approach 1:
The patent merges multiple transmission stages into a single integrated monolithic load cell structure. The upper frame, lower frame, and all lever mechanisms are produced as one piece using precision casting or machining, eliminating the need for separate assembly of multiple components. This reduces production complexity despite the increased number of transmission stages.
Solution Approach 2:
The transmission stages are arranged vertically in the Z-direction, utilizing the vertical dimension to accommodate multiple mechanisms without increasing horizontal space requirements. This compact vertical arrangement fits within the limited space of the scale housing while providing extended measuring range.
4Object-affected harmful factors
If levers are designed wide to reduce corner load sensitivity, then the corner load sensitivity decreases, but the installation space inside the scale is blocked
Solution Approach 1:
The patent transitions from horizontal lever arrangement to vertical stacking of transmission stages. The levers are arranged in the vertical Z-direction rather than spreading horizontally, which reduces corner load sensitivity through proper lever geometry while freeing up horizontal installation space for other scale components.
Solution Approach 2:
The weight force is segmented into multiple components handled by separate levers in different vertical stages. This segmentation allows each lever to be optimized for its specific function with appropriate dimensions, reducing the need for wide horizontal clearance while maintaining low corner load sensitivity.
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 approach enables a stable, high-resolution, and accurate precision scale that is insensitive to corner loads, allowing for larger measuring ranges and higher loads with reduced production complexity and costs.
Implementation Method 1
fed to a suitable force transducer for evaluation
Data Source
Figure 1
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Figure 3
AI summary
The weighing platform has two bridging elements (B-1), where force transmitting levers (H-11,H-12) are separately provided for each bridging element. The weight to be placed underneath is fed within the bridging element or in the direction of a force transducer (K) of the weighing platform. Each bridging element has a load cell (O-1) for receiving a partial weight and a base section (U-1) for supporting the lever provided in the bridging element.