Folding Door Linkage Converts Linear Drive Motion to Rotary Torque
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Solution Overview
Problem
Elevator car and shaft door arrangements with folding doors face challenges in efficiently opening and closing with minimal effort, especially when retrofitting older systems, due to high-torque requirements and space constraints, and existing solutions either require excessive installation space or additional complex and hazardous mechanisms.
Innovation Solution
A door system where the leading door leaf is directly connected to the drive via a linkage that converts the drive's movement into a rotary and then translational motion, allowing the door to open fully while minimizing torque requirements and avoiding interference between opening and closing phases, with a crank member that applies torque only when needed and stabilizes the door in the closed position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high-torque drive is used to overcome unfavorable lever ratios when the door is fully open, then the door can be reliably opened and closed, but the drive becomes expensive and complex
Solution Approach 1:
The linkage performs a preliminary pivoting action on the leading door leaf before the main translational movement. This preliminary rotation changes the geometric configuration to a more favorable position where the lever ratios are improved, allowing the subsequent translational movement to occur with reduced torque requirements and without needing a high-torque drive
2Area of stationary object
If the door leaves are completely stretched in the closed state, then the aesthetic appearance and space utilization are improved, but it becomes difficult or impossible to reliably initiate pivoting motion
Solution Approach 1:
The linkage applies a preliminary rotational action to the leading door leaf that creates sufficient torque to overcome the stable stretched configuration. This preliminary pivoting motion breaks the geometric lock of the completely stretched door leaves, enabling them to transition into the opening phase with favorable lever ratios
3Reliability
If a w-door design with inclined door leaves is used to ensure sufficient torque for pivoting, then reliable opening is achieved, but the installation space and floor space are significantly reduced
Solution Approach 1:
The linkage provides a controlled preliminary rotational action that temporarily creates the necessary torque for pivoting initiation, then allows the door to transition to the fully stretched closed position. This eliminates the need for permanent angular offsets between door leaves, maximizing installation space and aesthetic appearance while maintaining reliable pivoting capability
Solution Approach 2:
The system dynamically transitions between different geometric configurations: from the completely stretched closed position through a preliminary rotational phase with favorable lever ratios to the fully open position. This dynamic reconfiguration allows the door to achieve reliable pivoting without maintaining a fixed inclined configuration that would consume space
4Ease of operation
If deflection forks or devices are added to move door leaves out of dead center position, then opening can be initiated, but the device complexity and safety hazards increase
Solution Approach 1:
The preliminary pivoting function is merged into the existing linkage mechanism that connects the drive to the leading door leaf. This integration eliminates the need for separate deflection forks or devices, reducing overall system complexity while maintaining the ability to initiate door opening from the fully closed position
Solution Approach 2:
The linkage itself performs the function of creating favorable lever ratios through its geometric design and motion path. The mechanism uses its own structural characteristics to automatically generate the necessary preliminary rotational motion without requiring external deflection devices or additional safety mechanisms
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 reliable, low-effort opening and closing of folding doors with reduced installation space requirements, avoiding the need for high-torque drives and complex deflection mechanisms, while maintaining door stability and aesthetics.
Implementation Method 1
the coupling gear is designed in such a way that when the drive is started to open the door, it first converts the movement of the drive into a rotary movement, which is introduced into the leading door leaf - from the outside, usually by applying a torque to the third rotary axis
Data Source
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AI summary
The arrangement has a coupling drive (14R) for transferring linear movement of a toothed drive belt (12) into rotary movement during starting an actuator for opening a door, where the rotary movement is induced into a leading door wing (4R) by exerting a torque moment on a rotational axis (8R) of the door wing. A rotational axis (7R) of the door wing moves transverse to a guiding rail such that the linear movement is directly converted into a translational movement of the rotational axis (8R) of the door wing. The rotational axis (8R) is displaced in parallel along the rail.