Rolling Door Limit Position Safety Device

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Solution Overview

Problem

Existing rolling door systems lack efficient control mechanisms to prevent bouncing when fully open and ensure safe, controlled operation during emergencies, particularly in fire doors, with existing solutions either being unreliable or requiring complex adjustments.

Innovation Solution

A safety device for rolling doors that includes electrical limit switches and a direct drive gear system to control the door's position and speed, using a centrifugal governor to regulate the door's descent and prevent bouncing, with actuators to selectively engage or disengage the motor drive, allowing for manual or motorized operation and external motor integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical means (pendulums, oscillating governors, friction discs, ratchets) are used to allow door closure under spring pressure during fire emergencies, then the door can close automatically, but the mechanism becomes unreliable due to jamming or malfunctions

Engineering Contradiction:

Improvereliability of emergency door closureVSAvoidcomplexity of mechanical emergency release mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the emergency release function from complex mechanical means and implements it through a simple electrical circuit breaker that trips automatically during fires, directly controlling the motor to cease operation and allow spring-driven door closure without jamming mechanisms

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces unreliable mechanical emergency release mechanisms (pendulums, oscillating governors, friction discs, ratchets) with an electrical control system using a circuit breaker and motor control, eliminating mechanical jamming while maintaining emergency door closure functionality

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If limit switches are mounted inside the motor operator housing, then the system is compact, but adjustments require disassembly of the operator

Engineering Contradiction:

Improveease of limit switch adjustmentVSAvoidcomplexity of limit switch access

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary drive gear mechanism that transmits motion from the door to externally mounted actuators, allowing limit switches to be positioned outside the housing while maintaining functional integration, thus enabling easy adjustment without disassembly

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent relocates limit switches from the internal spatial dimension to the external dimension of the motor operator housing, using drive gear means to transmit control signals across the housing boundary, making adjustments accessible from the outside

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of operation

If the door is allowed to move freely into open position, then operation is simple, but the door may bounce after reaching the open position

Engineering Contradiction:

Improvefreedom of door movementVSAvoidstability of door position at open limit

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent implements feedback through limit switches that detect when the door reaches its open position and automatically signal the motor to cease operation, preventing over-travel and bouncing while maintaining free movement during normal operation

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by having the limit switch activate the motor stop function before the door can bounce, preemptively halting motion at the precise open position to maintain stability

Inventive Principle:

Principle #10Preliminary action

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 solution provides reliable, efficient, and safe operation of rolling doors by preventing bouncing and ensuring controlled movement, integrating multiple safety features for emergency situations while allowing for easy adjustment and maintenance without disassembly.

Implementation Method 1

using a centrifugal governor to regulate the door's descent and prevent bouncing

Methodology Applied

Scientific EffectCentrifugal governor: Centrifugal Govenor

Data Source

PatentUS11486195B2Limit position safety device for a rolling door

Publication Date: 2022.11.01 ALPINE OVERHEAD DOORS INC

AI summary

A limit position safety device for establishing upper and lower limit positions of a rolling door that can be raised when rolled onto a generally horizontal shaft when the shaft rotates in a first direction and lowered when the shaft rotates in an opposing direction. The device includes two electrical limit switches each actuatable to reflect when an associated limit position of the rolling door has been reached. Actuators are movable to selectively actuate one of the limit switches at associated upper or lower limit positions of the rolling door. Drive gear are directly coupled to the shaft for moving the actuators in response to movements of the rolling door horizontal shaft. Accordingly, the direct drive gears always provide a direct physical connection or link between the rolling door shaft and the actuators to provide reliable indications of the position of the rolling door.