Force Sensor Over-Force Transfer Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Force sensors face challenges in providing high resolution at low force levels while being protected against over-force events and maintaining compact packaging, as existing solutions either introduce noise issues or make the sensor vulnerable to over-forces.
Innovation Solution
A force sensor system incorporating a housing assembly, a sensor, an actuator, and an actuator travel stop, where the actuator is movable and transfers input force to the sensor, with a travel stop limiting movement and force transfer to prevent over-force events, potentially using a force transfer gel within the sensor cavity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensor sensitivity is increased to enhance output signals at low force levels, then measurement precision is improved, but the sensor becomes vulnerable to over-force events
Solution Approach 1:
The patent implements a mechanical over-force protection mechanism that includes a travel stop member and a compliant element (such as a spring or elastomeric material) positioned between the actuator and the sensor. This compliant element acts as a cushion that absorbs and limits the transmission of excessive forces to the sensor before they can cause damage, while still allowing the sensor to detect low force levels with high precision.
Solution Approach 2:
The patent introduces a travel stop member as an intermediary mechanical element between the actuator and the sensor. This travel stop member physically limits the maximum displacement of the actuator, thereby preventing over-force events from reaching the sensor. The compliant element serves as a mediator that selectively transmits forces below a threshold while blocking forces above the threshold.
2Measurement precision
If amplification gain is increased in signal processing circuitry to enhance output signals, then measurement precision is improved, but noise issues arise that influence stability and accuracy
Solution Approach 1:
The patent replaces electronic signal amplification with a mechanical leverage system. By designing the actuator and force transfer mechanism with appropriate mechanical advantage, the system naturally amplifies the force applied to the sensor without requiring high-gain electronic amplification, thereby avoiding the introduction of electronic noise while maintaining measurement precision.
3Reliability
If mechanical over-force protection is added to protect the sensor, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent combines the over-force protection function with the existing actuator and housing structures. The travel stop member is integrated into the housing assembly, and the compliant element is incorporated into the force transfer path between the actuator and sensor. This merging of protection functions into existing structural elements minimizes the increase in device complexity while providing reliable over-force protection.
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 system achieves high resolution at low force levels with built-in over-force protection, limiting actuator over-travel and force transfer to the sensor, ensuring stability and accuracy by redirecting excessive forces to the housing assembly.
Implementation Method 1
The force transfer gel is disposed within the sensor cavity between the actuator and the sensor to transfer the input force to the sensor
Data Source
Figure 1
Figure 2
AI summary
A force sensor system includes a housing assembly, a sensor, an actuator, and an actuator travel stop. The sensor is disposed within the housing assembly, and is configured to generate a sensor signal representative of a force supplied to the sensor. The actuator is disposed at least partially within, and is movable relative to, the housing assembly. The actuator extends from the housing assembly and is adapted to receive an input force. The actuator is configured, upon receipt of the input force, to move toward, and transfer the input force to, the sensor. The actuator travel stop is disposed within the housing assembly, and between the housing assembly and a portion of the actuator. The actuator travel stop is configured to be selectively engaged by the actuator and, upon engagement by the actuator, to limit movement of the actuator toward, and the input force transferred to, the sensor.