Installation Switching Device Double Interruption Mechanism
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Solution Overview
Problem
Generic installation switching devices experience contact chatter due to the mechanical inertia of the switching mechanism lagging behind the movement of the handle, causing the contact bridge to close prematurely before the switching mechanism can maintain a permanent open position during a short-circuit interruption.
Innovation Solution
The design features a contact bridge that is clamped between the legs of the latch, with a tapered distance at the free end allowing it to jam and prevent early closure, and a guide area for movement, along with a pusher mechanism that includes a slide and firing pin to ensure the contact bridge remains open until the switching mechanism can reset it.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the switching mechanism has greater mechanical inertia to maintain permanent open position, then the contact bridge can be kept open reliably, but the switching mechanism lags behind the handle movement causing contact chatter
Solution Approach 1:
The patent introduces an intermediary mechanism (the slot with tapered legs and contact bridge arrangement) that mediates between the fast-moving handle and the slower switching mechanism. The contact bridge is guided through a slot formed by two legs that converge toward the free end, creating a mechanical interface that translates the rapid handle movement into controlled contact bridge movement while allowing the switching mechanism to operate at its own slower pace.
Solution Approach 2:
The slot geometry is designed so that the contact bridge is preliminarily positioned and guided within the slot before the switching mechanism completes its full opening action. The tapered legs create a narrowing path that pre-positioned the contact bridge in a way that prevents premature closing, buying time for the inertia-prone switching mechanism to complete its movement.
2Ease of operation
If the contact bridge is allowed to move freely, then the switching mechanism can operate without constraint, but the contact bridge closes too quickly causing contact chatter
Solution Approach 1:
The slot structure serves as an intermediary constraint that guides the contact bridge movement. The two legs forming the slot create a controlled path that the contact bridge must follow, preventing it from moving too quickly or closing prematurely, while still allowing the switching mechanism to operate freely within this guided framework.
Solution Approach 2:
The slot geometry parameters (leg convergence angle, slot length, leg spacing) are optimized to change the effective movement parameters of the contact bridge. The tapered legs create a narrowing effect that progressively restricts the contact bridge's freedom of movement, converting uncontrolled rapid motion into controlled, extended opening movement.
3Reliability
If the legs are made resiliently elastic to improve clamping, then the contact bridge is held open more effectively, but the device complexity increases
Solution Approach 1:
The material parameter of the legs is changed from rigid to resiliently elastic, transforming their mechanical properties. This allows the legs to deform elastically under the action of the contact bridge and pusher, creating a self-adjusting clamping effect that improves contact bridge retention without requiring additional active control mechanisms.
Solution Approach 2:
The resiliently elastic legs provide self-service by automatically adjusting their clamping force based on the position and force of the contact bridge. The elastic deformation of the legs creates a restorative force that naturally holds the contact bridge in the open position without requiring external actuation or complex control systems.
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 effectively prevents contact chatter by maintaining the contact bridge in an open position long enough for the switching mechanism to reset, ensuring reliable operation during short-circuit interruptions and reclosing processes.
Implementation Method 1
a contact pressure spring (11) acting on the contact bridge (7) in the closing direction
Implementation Method 2
an electromagnetic release (13), the armature of which, when a short-circuit current occurs in the pole current path, opens the contact bridge (7) in the opening direction
Implementation Method 3
the legs (30, 31) are resiliently elastic. According to an advantageous embodiment, the legs (30, 31) can be bent towards one another towards the free end
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
The electrical switching device (1) has a double contact point (10) and a contact bridge (7), which is passed by an impact pin (20) against the pressure of a contact pressure spring (11) during a striking operation in opened position. The distance of the two brackets is tapered to each other at free ends. The distance at the free ends is smaller than the width of the contact bridge such that the contact bridge is jammed during a disconnection between the brackets. A pusher (12) is operated by a latch (15), in which the impact pin is guided.