Rack Shelf Escape Access Using Retractable Step Segments

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rack storage systems face limitations in providing easy and rapid access to maintenance aisles during emergencies, with conventional escape ladders requiring large installation space and reducing storage capacity.

Innovation Solution

A rack storage system with pedestrian passageways and ascent/descent units, allowing quick access and exit via movable step segments between storage racks, and optional personnel access points, ensuring rapid emergency egress and maintaining high storage capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional escape ladders are installed in rack storage systems, then emergency escape is enabled, but installation space is increased and storage capacity is reduced

Engineering Contradiction:
Improveemergency escape capabilityVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The step segment of the ascent and descent device is nested within the storage rack structure during normal operation, and only protrudes into the maintenance aisle when needed for emergency escape or maintenance access. This nesting approach allows the escape device to be integrated without permanently occupying maintenance aisle space.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The ascent and descent device features a movable step segment that can dynamically change its position between retracted (first operating position) and extended (second operating position) states. This dynamic capability allows the device to provide escape functionality only when needed, rather than permanently blocking maintenance aisle space.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If transport vehicle lifting devices are installed to enable access between driving levels, then maintenance access is improved, but device complexity and installation requirements are increased

Engineering Contradiction:
Improvemaintenance accessVSAvoidinstallation complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The ascent and descent device serves multiple functions: it enables emergency escape, facilitates maintenance access between driving levels, and can be integrated with existing storage rack structures. This multi-functionality reduces the need for separate dedicated escape and maintenance access systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The step segment is designed to be movable and operable by maintenance personnel or operators themselves, enabling self-service access between driving levels without requiring complex automated lifting mechanisms or external assistance.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the step segment protrudes into the maintenance aisle, then access and emergency egress are facilitated, but storage rack space is reduced

Engineering Contradiction:
Improvemaintenance aisle accessVSAvoidstorage rack space
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The step segment dynamically transitions between a retracted position (first operating position) that minimizes space occupation within the storage rack, and an extended position (second operating position) that facilitates maintenance aisle access and emergency egress. This dynamic positioning resolves the space conflict.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The ascent and descent device is segmented into a movable step segment that can be independently positioned. This segmentation allows the step segment to be extended only when and where needed for access, rather than permanently occupying space that could be used for storage.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4452784B1Shelf storage system
Publication Date: 2026.04.15 TGW LOGISTICS GMBH
  • EP4452784B1 patent drawingFigure 1a
  • EP4452784B1 patent drawingFigure 1b
  • EP4452784B1 patent drawingFigure 1c

AI summary

The invention relates to a shelf storage system comprising a first storage shelf (2a), a second storage shelf (2a), a shelf aisle (3), maintenance paths (4a, 4b, 4c) that run in the shelf aisle and comprise walkways (57) arranged on maintenance levels lying one over the other, guide tracks (5a, 5b), automatically operated transport vehicles (6) that can be driven along the guide tracks, and a transfer device (25). The shelf storage system additionally comprises a passageway (109a, 109b, 109c) for persons, which is paired with maintenance paths arranged one over the other and which is provided on a walkway, and an ascending and/or descending unit (108), which is paired with the passageway for persons and which is provided in one of the first and second storage shelves and comprises an ascending and/or descending device (130a, 130b, 130c) with a step segment (131) that is movably arranged between a first use position and a second use position relative to the aforementioned storage shelf of the first and second storage shelves such that the step segment is located in one of the first and second storage shelves in the first use position and at least partly protrudes into one of the maintenance paths in the second use position. In particular, the aforementioned arrangement allows an operator to quickly leave a maintenance path in case of an emergency, such as a fire for example.