Anti-rebound Lever for Electrical Switching Device
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Solution Overview
Problem
Electrical switching devices with separable contacts often experience accidental closure due to uncontrolled rebound of moving parts, which can lead to unintended current flow when the device is supposed to be in an open state, posing safety risks.
Innovation Solution
The introduction of an anti-rebound lever mechanically coupled to the control lever, which deploys when the control lever reaches its second position and cooperates with a stop to prevent the control lever from moving out of this position, utilizing angular momentum to maintain the control lever in the open position and prevent accidental closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the switching mechanism is actuated to separate the fixed and movable contacts to interrupt current flow, then the device achieves its switching function, but the movable contact may close accidentally due to uncontrolled rebound of moving parts
Solution Approach 1:
The anti-rebound lever is pre-configured to automatically deploy when the control lever reaches its end position, creating a preliminary counter-action that prevents the harmful rebound effect before it can cause accidental contact closure. The lever's geometry and pivot connection are designed to engage proactively at the moment the control lever stops, blocking any potential rebound motion.
Solution Approach 2:
The anti-rebound lever acts as an intermediary element between the control lever and the stop. It receives the motion from the control lever through the pivot connection and translates it into a blocking action against the stop, mediating the interaction to prevent harmful rebound while maintaining controlled motion during normal operation.
2Reliability
If the anti-rebound lever is deployed to prevent control lever movement, then accidental closure is prevented, but the device complexity increases due to additional moving parts
Solution Approach 1:
The anti-rebound lever is mechanically integrated with the control lever through a pivot connection, merging two functions into a coupled system: the control lever's motion control function and the anti-rebound lever's protective function. This integration allows the anti-rebound mechanism to be actuated passively by the control lever's own motion, reducing the need for separate actuation mechanisms.
Solution Approach 2:
The anti-rebound lever is designed to deploy automatically using the kinetic energy and motion of the control lever itself. When the control lever reaches its end position, the pivot connection transfers motion to the anti-rebound lever, causing it to deploy without external intervention. The system uses its own operating energy to activate the protective mechanism.
3Extent of automation
If the center of gravity of the anti-rebound lever is offset from the pivot connection, then angular momentum is generated to deploy the lever, but the manufacturing precision requirements increase
Solution Approach 1:
The design changes the physical parameter of the anti-rebound lever by deliberately offsetting its center of gravity from the pivot connection. This parameter modification creates an asymmetric mass distribution that generates automatic rotational motion (angular momentum) when the lever is actuated, enabling self-deployment without additional springs or actuators.
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 significantly reduces the risk of accidental contact closure, enhancing the safety and reliability of the switching device by ensuring the contacts remain open even after the switching mechanism has been actuated to interrupt the current.
Implementation Method 1
Thanks to the positioning of the center of gravity, when the control lever comes to a stop in its second position during a movement aimed at opening the moving contact, the angular momentum of the control lever is at least partly transmitted to the anti-bounce lever, which then moves to its deployed position
Data Source
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AI summary
This electrical switching device (2) with separable contacts comprises a switching device including: a fixed electrical contact (6) and a movable electrical contact (8) that can be moved between a closed position and an open position; a control lever (18) mechanically coupled to the movable electrical contact, the control lever being rotatable about a first axis of rotation (X18) between a first position and a second position; and a de-bouncing lever (26) arranged to move from a rest position to a deployed position when the control lever reaches the second position. The de-bouncing lever cooperates with a stop (24) when it is in its deployed position and the control lever is in the second position to prevent the control lever from leaving the second position.