Electric Switching Apparatus Shear Force Micro-weld Breaking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical switching devices face premature wear and inability to break micro-welds with significant resistant forces, leading to frequent maintenance and material wastage due to inefficient contact opening mechanisms.
Innovation Solution
The device transforms the translational movement of movable contacts into a combined translation and rotation during opening, applying a shear force to break micro-welds by using angular guidance means and springs, effectively transmitting torque to the contact points to exert shear stresses, thereby overcoming the limitations of prior art.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cam-operated device causes translational movement to break welds, then the electrical contacts can be separated, but this generates premature wear of the contact pads
Solution Approach 1:
Instead of using translational movement to break the weld (as in prior art), the invention inverts the approach by using rotational movement of the moving contact relative to the fixed contact. This rotation creates a rolling motion that breaks the microweld without sliding friction, thereby resolving the contradiction between achieving contact separation and preventing premature wear.
Solution Approach 2:
The invention introduces a curved or rounded contact surface on the moving contact that rolls over the fixed contact during opening. This curvature enables the rolling motion that breaks microwelds through rotation rather than translation, reducing wear on the contact pads while maintaining reliable contact separation.
2Ease of operation
If a torsional force is applied to facilitate separation, then the moving contact can be separated from the fixed contact, but this does not allow for breaking microwelds exhibiting significant resistance forces
Solution Approach 1:
The invention transitions from a static torsional force application to a dynamic rolling motion. The moving contact rotates and rolls over the fixed contact during opening, creating a time-varying force application that combines rotational torque with the breaking action. This dynamic approach enables the system to overcome significant microweld resistance forces while maintaining ease of operation.
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 solution enables the reliable breaking of micro-welds with high resistant forces, extending the service life of electrical contacts and reducing maintenance needs without altering the existing design or increasing operational forces.
Implementation Method 1
a shear force capable of breaking the aforementioned microweld
Implementation Method 2
a torque is transmitted to the microweld m by rotation of the movable contact around the axis of the aforementioned translation, this torque generating the aforementioned shear forces
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to an electrical switching device comprising, per phase, a fixed contact called upstream and a fixed contact called downstream, said fixed contacts being supported respectively by an upstream fixed contact support and a downstream fixed contact support and being electrically connected respectively to an upstream power line and a downstream power line, said fixed contacts being intended to cooperate respectively with two moving contacts respectively upstream and downstream, said moving contacts being supported each by a contact support, said contact supports being able to be moved simultaneously in translation by a contact holder controlled by an actuator.This device is characterized in that it includes means M for transforming, during an opening maneuver of the device in the presence of a microweld between one of the moving contacts and the associated fixed contact, the translational movement of the contact support (3,12) associated with the moving contact into a combined movement of translation and rotation of the moving contact (6,15) so as to exert at the points of contact between the moving contact (6,15) and the fixed contact (7,18), a shear force capable of breaking the aforementioned microweld (m).