Door Curtain Re-feeding Mechanism for Breakaway Protection

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Solution Overview

Problem

Existing door curtain systems face challenges in easy re-feeding and protection from collisions, particularly in industrial settings where they are susceptible to damage from forklifts and accidental closures, leading to wear and potential damage.

Innovation Solution

A door curtain system with separate mechanisms for normal operation and re-feeding, featuring retention buttons and a secondary edge bead that guides the curtain back into tracks after a breakaway event, along with sensors and a controller to manage door operation and reduce damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a single guiding mechanism is used for normal operation, then the device complexity is reduced, but the ease of operation deteriorates because the same mechanism cannot efficiently handle both normal operation and re-feeding after breakaway

Engineering Contradiction:
Improveease of re-feedingVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent divides the guiding mechanism into two separate systems: a first guiding mechanism (buttons and channels) for normal operation and a second guiding mechanism (edge bead and guideway) for re-feeding after breakaway. This segmentation allows each mechanism to be optimized for its specific function, making re-feeding easier without complicating normal operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the re-feeding function from the normal operation mechanism by introducing a separate second guiding mechanism. The edge bead and guideway system is specifically designed for re-feeding operations, allowing it to be taken out and operated independently without interfering with the primary button-based guiding system.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If the curtain is made rigid to resist wind and pressure differentials, then the strength is improved, but the reliability deteriorates because the rigid structure cannot absorb impact forces from collisions

Engineering Contradiction:
ImprovestrengthVSAvoidreliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies different structural qualities to different parts of the curtain: the main curtain body maintains rigidity to resist wind and pressure differentials, while the leading edge incorporates a breakaway feature with sufficient flexibility to absorb impact forces. This local differentiation of mechanical properties allows the curtain to simultaneously achieve strength for weather resistance and reliability for collision protection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The breakaway feature is designed in advance to absorb impact forces from potential collisions. By incorporating this flexible element at the leading edge before any collision occurs, the system prepares to cushion the impact, preventing damage to both the curtain and the vehicle, while the rigid main body continues to provide weather resistance.

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

3Reliability

If the curtain is made flexible to absorb impact, then the reliability is improved, but the manufacturing precision deteriorates because maintaining tension and square alignment becomes difficult

Engineering Contradiction:
ImprovereliabilityVSAvoidmanufacturing precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent segments the curtain into a flexible leading edge with the breakaway feature and a stiffer main body. This segmentation allows the flexible portion to absorb impacts reliably while the stiffer portion maintains tension and square alignment more effectively, reducing the manufacturing challenges associated with keeping the entire curtain taut and properly aligned.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3180488B1Systems and methods to retain and refeed door curtains
Publication Date: 2020.05.27 RITE HITE HLDG CORP
  • EP3180488B1 patent drawingFigure 1
  • EP3180488B1 patent drawingFigure 2
  • EP3180488B1 patent drawingFigure 3

AI summary

Systems and methods to retain and refeed door curtains are disclosed. A door (10) is disclosed that includes a track (16) and a curtain (14) that includes a leading section (18). The curtain (14) is to be in at least one of a breakaway state or a normal state, and in at least one of a folded condition or an unfolded condition while in the breakaway state such that: (a) in the normal state, a lateral section in an area proximate the leading section (18) is in guiding engagement with the track (16); (b) in the breakaway state while in the folded condition, the lateral section (19) in the area proximate the leading section (18) is dislodged from the track (16) and folded over onto the main section to define an enfolded space; and (c) in the breakaway state while in the unfolded condition, the lateral section (19) in the area proximate the leading section (18) is dislodged from the track (16) but not folded over onto the main section. The example door (10) also includes an unfolder (200) to be in a position to engage the lateral section (19) proximate the enfolded space as the leading section moves toward an open position while the curtain (14) is in the folded condition.