Adjustable Door Braking Mechanism for Controlled Closure Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fire door governors are not adjustable, leading to unsatisfactory drop speed control, and often result in doors accelerating and slamming upon closure, posing difficulties in adjusting spring tension and maintaining the system.
Innovation Solution
An adjustable door braking system that includes a shaft, brake pad, plate, spring, and nut configuration, allowing for variable braking force application based on door speed and position, with a connecting mechanism to a door release mechanism and a brake drum with adjustable braking force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional fire door governors are used with fixed spring tension, then the system is simple in structure, but the drop speed cannot be adjusted and the door accelerates and slams upon closure
Solution Approach 1:
The patent implements a dynamic braking system where the brake pad can be adjusted along the shaft to change the spring tension, allowing the door closure speed to be controlled. The system transitions from a static fixed-tension design to a dynamic adjustable-tension design, enabling operators to optimize door closure performance for different fire safety requirements.
Solution Approach 2:
The patent changes the parameter of spring tension from fixed to variable by introducing an adjustable brake pad mechanism. This allows the braking force to be modified by repositioning the brake pad on the shaft, thereby controlling the door drop speed without requiring complex electronic control systems.
2Ease of operation
If spring tension is adjusted to control drop speed, then door closure speed can be controlled, but the system becomes difficult to maintain and requires significant time and expense
Solution Approach 1:
The braking system is segmented into distinct components: the shaft, the brake pad, the plate, and the spring. This modular segmentation allows the brake pad to be independently adjusted and replaced without affecting other components, significantly easing maintenance requirements compared to integrated conventional governors.
Solution Approach 2:
The adjustable braking mechanism is extracted as a separate assembly that can be independently accessed, adjusted, and maintained. The brake pad can be removed and repositioned on the shaft without disassembling the entire door hoist system, reducing maintenance time and expense.
3Reliability
If conventional governors are used, then the basic door closing function is provided, but the door accelerates during closure and slams into the ground
Solution Approach 1:
The spring-loaded brake pad applies preliminary braking force to counteract the acceleration of the door during closure. The spring mechanism pre-loads the brake pad against the shaft, creating continuous friction that prevents the door from gaining excessive speed, thereby eliminating the harmful slamming effect before it occurs.
Solution Approach 2:
The patent converts the potentially harmful gravitational acceleration force into a beneficial controlled descent by using the spring-brake mechanism. The same gravitational force that causes the door to accelerate is now managed through controlled friction, transforming the harmful slamming effect into a safe, controlled closure process.
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 precise control over door closure speed, preventing slamming and facilitating automatic door operation in response to events like fires or security incidents, while being easier and less expensive to maintain than traditional systems.
Implementation Method 1
a spring for urging the plate to the brake pad, the spring configured to be mounted on the shaft
Implementation Method 2
a brake pad configured to be mounted to the shaft... urging the plate against the brake pad
Implementation Method 3
a brake drum configured to be mounted to the shaft and having a brake shoe pressing against the brake drum when the brake drum rotates
Data Source
AI summary
A door braking system includes: a shaft; a brake pad configured to be mounted to the shaft; a plate for mounting on the shaft adjacent to the brake pad; a spring for urging the plate to the brake pad, the spring configured to be mounted on the shaft; a nut dimensioned and sized to be mounted on the shaft for adjusting an amount of force the spring urges the plate against the brake pad. A method of applying variable amount of braking force to a door includes: attaching a brake pad and brake plate to a shaft; configuring a spring to urge the brake plate against the brake pad; mounting an adjustment piece to the shaft; and configuring the adjustment piece to move axially on the shaft as the shaft rotates to thereby vary a force the spring urges against the brake plate.