Blocking mechanism for a flap drive

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Solution Overview

Problem

Existing blocking devices for flap drives in fire protection systems are complex and inefficient in absorbing torque during fires, often failing due to high temperatures and mechanical stress, requiring a more reliable and economical solution.

Innovation Solution

A blocking device that irreversibly converts into a blocking state by triggering, utilizing two independently movable blocking elements and a drive device to apply force, with a triggering mechanism that activates at a specific temperature, ensuring the device remains in a blocking position until failure or repair, capable of absorbing torque across various rotational positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a blocking device is located on the output side of the damper actuator downstream of the gearbox, then it can block the damper in the event of a fire, but it must be designed to reliably absorb the entire torque acting back on the actuator under unfavorable fire conditions, increasing device complexity and reducing reliability

Engineering Contradiction:
Improveblocking reliabilityVSAvoidblocking device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blocking device is divided into two independently movable blocking elements instead of a single complex blocking mechanism. Each blocking element can independently engage with the transmission element, distributing the torque absorption function across multiple simpler components rather than requiring one complex component to handle all torque

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blocking elements are pre-positioned and spring-loaded during normal operation but remain held back by a retaining device. In the event of fire, the retaining device releases, allowing the blocking elements to automatically engage the transmission element without requiring complex control systems during the emergency

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If a single blocking element is used, then the device structure is simpler, but it may fail to reliably block the transmission element under high torque conditions during fires

Engineering Contradiction:
Improveblocking device simplicityVSAvoidblocking reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

Two separate blocking elements are positioned at different locations on the transmission element, each capable of engaging at different rotational positions. This ensures that regardless of the transmission element's orientation during fire, at least one blocking element will be in a position to effectively block torque transmission

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The blocking elements are designed with spring loading and pre-tensioning mechanisms that prepare them for immediate engagement. The independent movable mounting allows each element to independently absorb and distribute mechanical stress, providing redundancy against failure under high torque conditions

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 a reliable and economical means to maintain the flap drive in a blocked state during fires, effectively absorbing torque and preventing unintended movement, even under high temperatures and mechanical stress, ensuring safety and operational reliability.

Implementation Method 1

the drive device is designed to apply a force on the blocking elements in the direction of their blocking positions

Methodology Applied
Scientific EffectElastic potential energy: Spring

Data Source

PatentEP3897874B1Blocking mechanism for a flap drive
Publication Date: 2023.07.12 BELIMO HOLDING AG
  • EP3897874B1 patent drawingFigure 1~2
  • EP3897874B1 patent drawingFigure 3
  • EP3897874B1 patent drawingFigure 4~5

AI summary

The invention relates to a blocking device (4) for a damper actuator, said device comprising a transmission element (14) which rotates when the damper actuator is actuated, wherein the blocking device (4) can be irreversibly transferred from an initial state into an alternative blocking state by being triggered. The blocking device (4) comprises a first blocking element (41a) and a second blocking element (41b). The blocking elements (41a, 41b) are each designed to permit a rotational movement of the transmission element (14) when in their respective release positions and to block a rotational movement of the transmission element (14) by means of engagement when in their respective blocking positions. The blocking device also comprises a drive device (43a, 43b), wherein the drive device (43a, 43b) applies a force to the first blocking element (41a) and to the second blocking element (41b) in the direction of their respective blocking positions. The blocking device also comprises a retaining device (44, 45) and a trigger device (46), wherein the trigger device (46) irreversibly deactivates the retaining device (44, 45) when a trigger temperature is exceeded and/or when a trigger heat is applied, thereby triggering the blocking device (4).