Spring Break Safety Device for Sectional Doors

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Solution Overview

Problem

Existing spring break safety devices for vehicle bodies, such as trucks, are prone to clogging due to exposure to weather and dirt, and require a compact design that does not restrict loading volume or opening access.

Innovation Solution

A spring fracture safety device with a pivotable, prestressed blocking lever engaged by a pinion on a spring shaft, held by an adapter on a holder, which disengages and re-engages with the pinion upon spring failure, ensuring mechanical fixation of the sectional door even under vibration, and is designed for compactness with arcuate holes for secure mounting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spring break safety device is provided for the spring shaft, then the sectional door is protected against uncontrolled movement in case of spring failure, but the device complexity increases due to additional components like locking levers, pinions, and adapters

Engineering Contradiction:
Improvespring break protectionVSAvoidsafety device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The safety device components (locking lever, pinion, adapter) are integrated into a compact assembly mounted on the holder, combining multiple functions into a unified structure that reduces overall complexity while maintaining reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking lever is pre-tensioned by a tension spring to automatically engage with the pinion when the adapter pivots upon spring failure, eliminating the need for complex control mechanisms and ensuring immediate protective action

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the locking lever is pre-tensioned to automatically engage with the pinion, then the safety device operates reliably under vibrations, but the device occupies more space affecting loading volume

Engineering Contradiction:
Improvelocking reliability under vibrationVSAvoidloading volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The locking lever is positioned in a recess between the adapter and holder section, nesting the components within each other to minimize the external dimensions of the safety device and preserve loading volume

Inventive Principle:
Principle #7Nested doll (Nesting)

3Device complexity

If the locking lever is positioned in a recess between adapter and holder, then the device achieves compact design, but the manufacturing precision requirements increase for proper assembly

Engineering Contradiction:
ImprovecompactnessVSAvoidassembly precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The adapter has arcuate slots instead of straight slots, allowing the adapter to pivot smoothly and automatically position itself correctly relative to the locking lever and pinion, reducing the need for high manufacturing precision in the recess geometry

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 fixation of the sectional door in case of spring breakage, withstands environmental exposure, and maintains operational access without hindering loading or opening functionality, even under torsional forces.

Implementation Method 1

the locking lever is in a position pre-tensioned by the spring keeps the locking lever out of engagement with the pinion

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

the spring shaft is connected on opposite sides to a cable drum for raising the panels of the sectional door

Methodology Applied
Scientific EffectTorsional force transmission: Torque

Data Source

PatentEP3371400B1Vehicle body
Publication Date: 2020.04.15 WIHAG FAHRZEUGBAUSYST
  • EP3371400B1 patent drawingFigure 1
  • EP3371400B1 patent drawingFigure 2
  • EP3371400B1 patent drawingFigure 3

AI summary

The invention relates to a vehicle body, in particular for a truck, having a loading space closable at an opening by a sectional door (1) which has a plurality of panels (2) arranged pivotably on one another which are movable via a drive, wherein at least one spring (10) on a spring shaft (7) supports a lifting of the sectional door (1), and a spring fracture safety device (13) is provided for arresting the sectional door (1) in the event that the spring (10) fractures, wherein the spring fracture safety device (13) has a pinion (16) connected to the spring shaft (7) and a pivotable, pretensioned locking lever (18) which can be engaged with the pinion (16) to lock a rotational movement of the spring shaft (7), wherein one end of the spring (10) is held on an adapter (21) which is mounted pivotably on a bracket (14) and, in a position tensioned by the spring (10), holds the locking lever (18) out of engagement with the pinion (16), and, in the event that the spring (10) fractures, releases the locking lever (18) so that the locking lever engages with the pinion (16).