Power-Close Door Closer With Dynamic Spring Preload Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing door closers struggle to meet regulatory requirements for both manual opening forces and closing forces, often exhibiting inefficiencies due to mechanical losses, particularly in compliance with standards like the Americans with Disabilities Act (ADA), where doors need to open with 5 lbs. or less force but close with a force greater than the opening force due to frictional losses.
Innovation Solution
A door closer system incorporating a force adjustment device, such as a motor, to dynamically adjust the pre-loading of a spring during opening and closing, controlled by a controller and position sensor, allowing for customizable forces to meet regulatory and user needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a door closer uses a spring mechanism to close the door, then the door closes automatically, but the closing force is insufficient to overcome mechanical losses and friction
Solution Approach 1:
The patent applies dynamics by making the spring pre-load adjustable during operation. The force adjustment device dynamically changes the spring's pre-load force based on door position and operational requirements, allowing the closing force to be optimized to overcome mechanical losses while maintaining ease of opening when needed.
Solution Approach 2:
The patent changes the force parameter of the spring mechanism by using an adjustable pre-load system. The force adjustment device modifies the spring's pre-load parameter in real-time, enabling the door closer to provide sufficient closing force to overcome friction and mechanical losses while still allowing easy manual opening when required.
2Force
If the spring pre-load is increased to improve closing force, then the door closes with sufficient force, but the opening force becomes too high for compliant operation
Solution Approach 1:
The patent makes the spring pre-load dynamic rather than static. The force adjustment device continuously or periodically adjusts the pre-load based on door position and operational state, providing high closing force when needed while reducing opening force to meet accessibility requirements such as ADA compliance.
Solution Approach 2:
The force adjustment device operates periodically or at specific phases of door operation. It increases pre-load during closing phases to ensure sufficient closing force, then reduces pre-load during opening phases to maintain ease of operation and regulatory compliance.
3Device complexity
If a fixed spring pre-load is used, then the device structure is simple, but the door cannot meet both opening force limits and closing force requirements simultaneously
Solution Approach 1:
The patent introduces a dynamic force adjustment mechanism that allows the spring pre-load to be modified during operation. This dynamic capability enables the door closer to adapt to different operational requirements, meeting both opening force limits and closing force needs without requiring multiple fixed-preload springs or complex mechanical systems.
Solution Approach 2:
The force adjustment device serves multiple functions: it adjusts spring pre-load to optimize closing force, maintains ease of opening for accessibility compliance, and adapts to varying door positions and operational conditions. This multi-functionality allows a single device to replace what would otherwise require multiple specialized components.
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 system ensures doors can open with a force of 5 lbs. or less while closing with a force greater than the opening force, enhancing compliance with regulations and user convenience by dynamically adjusting spring pre-load to maintain efficient operation.
Implementation Method 1
A door closer system incorporating a force adjustment device, such as a motor, to dynamically adjust the pre-loading of a spring during opening and closing
Implementation Method 2
A door closer may utilize a door closing device and a force adjustment device in order to allow for manual door opening and assisted door closing
Data Source
AI summary
A door closer may utilize a door closing device (e.g., spring) and a force adjustment device (e.g., a motor) in order to allow for manual door opening and assisted door closing. During operation, as a door is manually opened, the spring is loaded (e.g., compressed or tensioned) above its pre-loaded closed position state. Once manual opening is completed, the spring that is loaded during opening begins returning to the pre-loaded closed position state, and thus, moves the door automatically towards the closed position. Depending on the pre-loaded spring setting, the closing force of the door may not be enough to close the door, or to close the door with the preferred force. As such, during closing a controller may engage a motor not to drive the door directly, but to increase the pre-load of spring to increase the closing force in order to allow the door to close as preferred.