Inward Swinging Door Lever Mechanism for Speed Control
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Solution Overview
Problem
Existing systems for closing and opening inward swinging doors in passenger transport vehicles lack effective control over the speed of the door leaf, leading to sudden movements, especially on sloping ground, and are vulnerable to failure and vandalism, with high maintenance and manufacturing costs due to complex mechanisms and reliance on pneumatic or electric actuation.
Innovation Solution
A system with a rotatable lever and push-pull means linked to a carriage, where actuation means can distribute force interchangeably between the lever and carriage, using an electric motor with dual transmission mechanisms to ensure uniform movement and secure locking, independent of the motor's action in the closing position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If pneumatic or electric actuation means are used to rotate the vertical bar, then the door can be opened and closed, but the speed control of the door leaf becomes ineffective and sudden movements occur
Solution Approach 1:
A decoupling mechanism is introduced between the actuation means and the door leaf, allowing the system to separate the actuation function from the speed control function. The mechanism includes a lever that can rotate independently of the vertical bar, acting as an intermediary that absorbs excess motion and provides smooth speed control during door operation.
Solution Approach 2:
The system transitions from a rigid fixed connection between the vertical bar and lever to a dynamic decoupled connection. The lever is allowed to rotate independently about its own axis while maintaining connection to the door leaf, enabling adaptive speed control that responds to the door's position and load conditions in real-time.
2Speed
If a high ratio gear system is used in electric motor actuation, then low rotation speed of the bar is achieved, but the system becomes irreversible and requires a decoupling system
Solution Approach 1:
The high ratio gear system is extracted and replaced with a direct connection between the electric motor and the vertical bar. The speed reduction function is transferred to the lever mechanism itself, which naturally provides speed control through its geometry and independent rotation capability, eliminating the need for complex gear systems.
Solution Approach 2:
The complex mechanical gear system is replaced with a simpler direct-drive electric motor system combined with a lever mechanism. The lever's geometry and independent rotation provide the necessary speed control and decoupling functions that previously required complex gear trains, reducing overall system complexity.
3Device complexity
If the vertical bar rotates about its axial shaft with fixed lever connection, then the structure is simple, but the door leaf experiences sudden movements especially on sloping ground
Solution Approach 1:
The fixed rigid connection is replaced with a dynamic decoupled connection that allows the lever to rotate independently. This dynamic capability enables the system to adapt to varying load conditions, particularly on sloping ground, by allowing the lever to absorb gravitational effects and provide smooth, controlled door leaf movement throughout the opening and closing cycle.
Data Source
AI summary
The system comprises a lever (2) that is rotatable about a point fixed to the vehicle and articulately joined to the upper edge (6) of the leaf (1); a horizontal guide (3) through which a carriage (4) slides; push-pull means (10,11) that articulately link the upper edge (6) to the carriage (4); and actuation means (12) simultaneously linked to the lever (2) and the carriage (4), which are adapted to distribute their action on the lever (2) and the carriage (4) depending on the force to overcome in order to open and close the leaf (1), such that their action is automatically distributed on the lever (2) when greater power is required to move the carriage (4), this is essentially during the initial opening operation from the end closing position, and during the closing and locking operation from an imminent closing position.