Emergency Door External Controller With Gear-Reduced Latch Retraction
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Solution Overview
Problem
Conventional emergency door handles and panic bars lack an effective mechanism for actuation from the external side, often requiring high mechanical loads and complex components, and are not easily sourced or cost-effective.
Innovation Solution
An external controller for emergency devices featuring a simple structure with a gear system that reduces the mechanical force required for latch retraction, using a protruding actuator and a gear train to facilitate actuation with low mechanical loads, compatible with common components like door pulls and knobs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cylinder locks are used for emergency door handles, then latch retraction can be achieved, but high mechanical loads are required and the structure becomes complex
Solution Approach 1:
A gear system is introduced as an intermediary mechanism between the cylinder lock and the latch. The gear system includes a pinion gear connected to the lock cylinder and a larger gear connected to the latch, creating a mechanical advantage that reduces the force required by the user while maintaining reliable latch retraction.
Solution Approach 2:
The locking mechanism is divided into separate functional components: the cylinder lock for key operation, the gear system for mechanical advantage, and the latch for door securing. This segmentation allows each component to be optimized independently, with the gear system specifically addressing the force requirement.
2Force
If complex gear systems are added to reduce mechanical force, then actuation becomes easier, but device complexity increases
Solution Approach 1:
The gear system serves as a simple intermediary that provides mechanical advantage without requiring complex control mechanisms. The direct mechanical connection through gears ensures reliability while maintaining simplicity in the overall structure.
Solution Approach 2:
The gear system automatically provides mechanical advantage through its inherent gear ratio, eliminating the need for additional control systems, sensors, or complex actuation mechanisms. The system self-regulates the force requirement through pure mechanical design.
3Ease of operation
If specialized components are used for external controller actuation, then actuation effectiveness improves, but cost increases and components are harder to source
Solution Approach 1:
The actuator is designed with a universal interface that can accommodate multiple types of operating components including knobs, lever handles, and push buttons. This universal design allows the same basic mechanism to serve different application requirements while using commonly available components.
Solution Approach 2:
The design favors simple, inexpensive components that can be easily manufactured and replaced if needed. The gear system and actuator mechanisms use standard materials and construction methods that keep costs low while maintaining adequate service life for emergency applications.
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
Enables efficient and safe actuation of latches with reduced mechanical effort, ensuring easy installation, low costs, and reliable operation, suitable for various design requirements.
Implementation Method 1
at least one gear system, interposed between a pivoting shaft of said grip portion and said cylinder lock, which defines a specific mechanical reduction ratio between the moment necessary for the retraction of the at least one latch and the moment applied by the user on the key
Data Source
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AI summary
An external controller (1) for emergency devices for opening doors to passages to access and exit an environment, the devices comprising actuation means for respective latches associated with a face of the door directed toward the inside of the installation environment and a cylinder lock (6) operatively associated with the actuation means and with the latches. The controller (1) comprises: at least one actuator (2) provided with a fixed grip portion (3) for a user, at least partially protruding from an external face of the installation door, the actuator (2) being configured to produce the retraction of at least one of the latches upon the movement by a user of the key (6a) in the cylinder lock (6); at least one gear system (4), interposed between a pivoting shaft (5) of the grip portion (3) and the cylinder lock (6), which defines a specific mechanical reduction ratio between the moment necessary for the retraction of the at least one latch and the moment applied by the user on the key (6a) in order to impose such retraction.