Circuit Breaker Reset Hook Mechanism for Reliable Drawer Rearming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical protection devices, such as circuit breakers, often require mechanical power from a stirrup spring to return to their initial armed position after a fault, which may not be sufficient, leading to unreliable resetting.
Innovation Solution
An electrical protection device with a switching mechanism and a force amplifier system using a switching handle to reliably reset the drawer to its armed position, utilizing a reset hook and drawer hook engagement to ensure sufficient force for resetting, independent of the stirrup spring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stirrup spring is used to return the drawer to the armed position, then the device structure is simple, but the mechanical power is insufficient for reliable resetting
Solution Approach 1:
A force amplifier mechanism is introduced as an intermediary between the stirrup spring and the drawer. This mechanism includes a force amplifier lever that multiplies the mechanical power from the stirrup spring, enabling reliable resetting without requiring a more powerful spring. The force amplifier acts as a mediator that transforms insufficient force into sufficient resetting power.
Solution Approach 2:
The force amplifier mechanism changes the force parameter by applying mechanical advantage through lever arms of different lengths. The force amplifier lever rotates about an axis with a first arm connected to the stirrup spring and a second arm connected to the drawer, creating a force multiplication effect that increases the mechanical power available for resetting the drawer to the armed position.
2Adaptability or versatility
If multiple protection devices are used for different fault types, then comprehensive protection is achieved, but the overall system size increases
Solution Approach 1:
Multiple protection functions for different fault types are merged into a single integrated device. The device combines overload protection, short-circuit protection, and differential fault protection in one unit, sharing common components such as the housing, drawer, switching mechanism, and force amplifier system. This consolidation achieves comprehensive protection coverage while minimizing the overall system size.
Solution Approach 2:
The protection device is designed with multi-functionality to handle various fault types. The switching mechanism and contactors can respond to different trigger conditions (overload, short-circuit, differential fault), making a single device universal for multiple protection purposes. The force amplifier and drawer mechanism serve all protection functions, eliminating the need for separate devices for each fault type.
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 device ensures reliable resetting of the protection mechanism, maintaining functionality without modifying tripping and resetting processes, and achieves compact design suitable for various electrical fault types.
Implementation Method 1
a drawer spring, which applies an actuating force to the drawer, tending to move the drawer from the armed position to the free position
Implementation Method 2
a lock, which comprises a blocking relief configured to block the drawer in the armed position
Implementation Method 3
the movement of the switching handle from its open position to its closed position causes the drawer hook and the reset hook to engage and the drawer to be moved by the switching handle until the electrical protection device is reset
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Electrical protection device (1), comprising a switching mechanism (40) configured to switch between an armed and a triggered configuration, a drawer (61) movable between an armed position and a free position, characterized in that the electrical protection device includes a reset hook kinematically linked to the switching handle (50), the drawer carries a drawer hook; when the drawer is in the free position, the reset hook and the drawer hook are ready to engage and when the drawer is in the armed position, the drawer hook and the reset hook are separated from each other and the resetting of the electrical protection device results in the engagement of the drawer hook and the reset hook and a movement of the drawer.