Planar Load Cells for Ultra-Flat Scales
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing scales with double bending beam load cells have a large overall height, leading to storage difficulties and increased tripping risks, and are prone to measurement inaccuracies due to torque and force shunts.
Innovation Solution
The use of at least three planar load cells arranged between the load plate and base plate, with a flat and elastic base plate design, reduces overall height and eliminates torque-induced measurement errors by distributing force evenly across the base plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If double bending beam load cells are used, then measurement accuracy is improved by compensating for torque, but the overall height of the scale increases making it difficult to store and increasing tripping risk
Solution Approach 1:
The patent changes the geometric parameters of the load cell structure from a double bending beam design to a planar load cell design with deformation sections arranged in a plane. This parameter change maintains the torque compensation capability while reducing the overall height from the vertical dimension to a planar configuration, resolving the contradiction between measurement accuracy and compactness.
Solution Approach 2:
The patent transitions from a three-dimensional double bending beam structure to a two-dimensional planar load cell structure. By arranging the first and second deformation sections in a plane rather than in vertical stacking, the invention achieves torque compensation without increasing the overall height, effectively using dimensionality change to resolve the spatial constraint.
2Stability of the object's composition
If feet are arranged on the base plate to support the scale, then the structure provides stable support, but the force shunt causes measurement inaccuracies
Solution Approach 1:
The patent removes the feet from the base plate structure, extracting the source of the force shunt problem. By eliminating the feet and using the entire flat base plate surface for load distribution, the invention prevents the force shunt effect while maintaining structural stability through the distributed load path across the planar load cells.
3Reliability
If the load plate and base plate are positioned far apart to accommodate traditional load cells, then the load cells can function properly, but the scale has large overall height reducing storability
Solution Approach 1:
The patent nests the planar load cell structure within the minimal space between the load plate and base plate. By using a planar configuration with first and second deformation sections arranged in-plane rather than stacked vertically, the load cell fits within a compact thickness, enabling the load plate and base plate to be positioned close together while maintaining full load cell functionality.
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 results in a compact, ultra-flat scale with high measurement accuracy, allowing for easy storage and preventing force shunts, with a height of 6 to 16 mm, and accurate weight measurement even when objects are placed off-center.
Implementation Method 1
a bending element with a first, load-side fastening section and a second, bottom-side fastening section, which are connected to one another via at least one deformation section, with which means for measuring the deflection of the deformation section as a result of a load to be weighed applied to the load plate
Implementation Method 2
at least one deformation section, with which means for measuring the deflection of the deformation section
Data Source
Figure 1~2A
Figure 2B
AI summary
The scale (1) has a flexible base plate arranged below a rectangular load plate (10), and a unit to measure deflection of deformation portions of planar load cells (2). The unit transmits a measured value to evaluation electronics, which calculates weight to be measured from the deflection of the deformation portions and outputs the weight. The cells are fastened to the load plate via a load-side fastening portion (21) and rest on supports via a bottom-side fastening portion (22). The supports are upwardly directed from the base plate and are used to support the bottom-side fastening portion. The load plate comprises an insertion device for a flat minicomputer i.e. tablet personal computer, and smart phone, or is formed by the minicomputer.