Elevator Speed Limiter Automatic Reset via Rotation Reversal
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Solution Overview
Problem
Existing speed limiters for elevators require manual intervention to reset after triggering, which is inconvenient and can lead to prolonged downtime if the elevator car or counterweight is stopped between floors.
Innovation Solution
The speed limiter design allows the centrifugal body to automatically return to its decoupling position by reversing the direction of rotation of the drive body, eliminating the need for manual intervention and ensuring the speed limiter can be reused without further measures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the centrifugal body is designed to remain in the coupled position after triggering until manual reset, then the safety connection is maintained, but the device complexity and ease of operation deteriorate due to required manual intervention
Solution Approach 1:
The patent inverts the traditional reset mechanism by making the centrifugal body automatically return to the decoupling position when the drive body reverses rotation direction. Instead of requiring manual intervention to reset, the system uses the natural reversal of rotation (during normal elevator operation between up and down trips) to automatically reset the safety device, thereby maintaining reliability while eliminating manual reset requirements
2Reliability
If manual intervention is required to reset the centrifugal body, then the safety gear remains reliably engaged, but the loss of time and productivity increase due to service personnel access requirements
Solution Approach 1:
The patent implements self-service by enabling the centrifugal body to automatically return to its decoupling position through the reversal of drive body rotation. The system uses its own operational cycle (reversal of elevator direction) to automatically reset the safety mechanism without requiring external service personnel, thereby eliminating downtime and maintaining continuous operational availability
3Ease of operation
If the centrifugal body automatically returns to decoupling position upon rotation reversal, then the ease of operation and productivity improve, but the reliability may deteriorate if the return mechanism fails
Solution Approach 1:
The patent employs a restoring force mechanism (acting as a counterbalancing force) that actively pulls the centrifugal body back to the decoupling position when centrifugal force decreases. This restoring force ensures reliable automatic return by counteracting any forces that might prevent the centrifugal body from returning to its initial position, thereby maintaining both automatic operation and high reliability
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 automatic reset mechanism allows for quick reactivation of the speed limiter, enabling the elevator to resume operation without manual access, and ensures the safety gear can be triggered again when necessary, maintaining operational efficiency and safety.
Implementation Method 1
the at least one centrifugal body which can be pivoted about a pivot axis is mounted offset to the axis of rotation... the centrifugal body being able to be pivoted out against the action of a restoring force as the rotational speed of the drive body increases
Data Source
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AI summary
The limiter (20) has centrifugal bodies (41, 42) pivotable with rotational speed of a drive body (22) against action of reset force in a coupling position based on a decoupling position. The centrifugal bodies are coupled with a driven body (26) in the coupling position, for activation of a gripping device. The coupling of the centrifugal bodies with the driven body is maintained independent of the rotational speed of the drive body. The centrifugal bodies are automatically decoupled from the driven body by reverse rotation of the drive body.