Rotational Rheometer Normal Force Limiting Mechanism
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Solution Overview
Problem
Rheometers without built-in normal force measurement are prone to mechanical overload and damage due to varying forces during sample testing, leading to instability in the measuring gap and potential damage to sensitive components.
Innovation Solution
A mechanically based normal force limitation system using spring units and switching contacts that absorb forces up to a predetermined limit without moving the measuring parts, ensuring the measuring gap remains constant and preventing damage by interrupting the adjustment movement when forces exceed the limit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If normal force measurement is not built-in, then the device complexity is reduced and cost is lowered, but the reliability deteriorates due to mechanical overload and damage risk
Solution Approach 1:
The patent implements a mechanical limiting device with spring elements and switching contacts that are pre-configured to detect and respond to excessive normal forces before they can cause damage to the rheometer. The spring elements are pre-compressed to a specific force threshold, and the switching contacts are positioned to open the control circuit when this threshold is exceeded, thereby preventing overload damage in advance.
2Ease of operation
If the measuring gap is adjusted manually or mechanically, then the ease of operation is improved, but the manufacturing precision deteriorates due to difficulty in maintaining constant gap distance
Solution Approach 1:
The patent incorporates a feedback mechanism where switching contacts continuously monitor the normal force acting on the measuring parts. When the force exceeds a predetermined threshold, the contacts open the control circuit, providing feedback that stops further adjustment movement. This feedback loop ensures the measuring gap remains within safe limits while allowing manual or mechanical adjustment operation.
3Productivity
If the adjustment movement is not interrupted, then the productivity is improved, but the object-affected harmful factors worsen due to mechanical overload and damage
Solution Approach 1:
The limiting device is designed to be self-acting, automatically detecting excessive normal forces through spring elements and switching contacts, and autonomously interrupting the adjustment movement by opening the control circuit without requiring external intervention. This self-service mechanism protects the rheometer from overload damage while maintaining productivity by allowing continuous operation within safe force limits.
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 effectively limits normal forces to prevent mechanical overload, maintaining the integrity of the measuring gap and protecting sensitive components, allowing for precise and safe sample characterization without altering the gap geometry.
Implementation Method 1
a spring unit (50) is provided with which two components (10, 31) and contact parts (31, 41) of switching contacts (40) are pressed against or towards one another by spring force
Implementation Method 2
at least one spring unit (50) is provided with which these two components and the contacts of the switching contact are pressed against or towards one another by spring force and are held in this position
Data Source
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AI summary
The invention relates to a rotational rheometer with two measuring elements (20, 30) that define the measuring gap (S) and are movable relative to each other in a predetermined direction of movement (R) by means of an adjustment device (1). According to the invention, at least one switching unit with switching contacts (40) is provided for the operation of the adjustment device (1), which responds to changes in the force flow in the force circuit (K) of the rotational rheometer defined by the measuring elements (20, 30). This switching unit stops the adjustment device (1) when a predetermined limit value for the force flow in the positive or negative direction is exceeded, optionally even without relative movement of the measuring elements or when the measuring elements (20, 30) remain in a fixed position.