Sliding-Door Retractable Step Without Motorized Deployment

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Solution Overview

Problem

Existing rotorcraft and vehicle designs face challenges with retractable steps that are either complex, energy-consuming, or cumbersome, particularly in requiring motorized installations that complicate integration with existing vehicles.

Innovation Solution

A non-motorized mechanical deployment system connected to a sliding door, which automatically moves the step between retracted and deployed positions using the energy from the door's operation, and includes a safety device to prevent door blocking, allowing for easy integration and reduced energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a motorized installation is used to move the step between retracted and deployed positions, then the step can be positioned accurately, but the device becomes complex and energy-consuming

Engineering Contradiction:
Improvestep positioningVSAvoidmotorized installation
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The step system uses the sliding door itself as the actuating mechanism. The door's movement directly drives the step deployment through a mechanical linkage system, eliminating the need for separate motors or power systems. The door opening action automatically deploys the step, and door closing automatically retracts it, making the system self-servicing without external power sources.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The sliding door serves dual functions: providing access to the vehicle interior and simultaneously actuating the step deployment mechanism. The mechanical linkage system allows the door to perform both its primary sealing function and the secondary function of controlling step position, reducing overall system complexity by combining multiple functions into existing components.

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

2Ease of operation

If a motorized installation is used to move the step, then the step can be deployed on demand, but energy consumption increases

Engineering Contradiction:
Improvestep deployment controlVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system captures and utilizes the kinetic energy already present in the door opening/closing motion to drive the step deployment. No additional energy sources are required - the door's natural movement provides all the energy needed to extend or retract the step through the mechanical transmission system.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The step deployment occurs periodically in sync with door operations. Each door opening cycle deploys the step, and each closing cycle retracts it, creating a rhythmic, event-driven operation pattern that eliminates continuous energy consumption and activates the mechanism only when needed.

Inventive Principle:
Principle #19Periodic action

3Adaptability or versatility

If a retractable staircase with several steps is used, then ground clearance is accommodated, but the installation becomes cumbersome and heavy

Engineering Contradiction:
Improveground clearance adaptationVSAvoidstaircase weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

Instead of a single multi-step staircase structure, the system uses a single step that deploys horizontally from the door. This segmented approach separates the access function (door) from the stepping function (single deployable step), eliminating the need for a heavy, multi-level staircase while still providing adequate ground clearance accommodation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extracts only the essential stepping function from a traditional staircase, implementing a single lightweight step that extends from the door assembly. This removes the unnecessary weight of multiple steps, supports, and complex folding mechanisms while retaining the core functionality of bridging the gap to the ground.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If a fixed step is permanently deployed, then passenger support is always available, but aerodynamic impact increases

Engineering Contradiction:
Improvepassenger support availabilityVSAvoidaerodynamic impact
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The step transitions from a static, fixed position to a dynamic, movable one that can extend or retract based on operational conditions. During flight, the step remains retracted to minimize aerodynamic drag, and only deploys when the vehicle is on the ground and passenger access is required, optimizing both aerodynamic performance and functional availability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The step's position parameter changes between two discrete states: retracted (aerodynamically optimized) and deployed (functionally optimized). This parameter switching allows the system to adapt to different operational phases - maintaining low drag during flight while providing full support functionality during ground operations.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3828075B1Vehicle equipped with a step having a retractable footboard
Publication Date: 2023.11.29 EUROCOPTER FRANCE SA
  • EP3828075B1 patent drawingFigure 1~2
  • EP3828075B1 patent drawingFigure 3~4
  • EP3828075B1 patent drawingFigure 5~6

AI summary

The present invention relates to a vehicle (1) equipped with a sliding door (5) and a step (10) activated by the door, the step (10) comprising a movable step (15) from a retracted position (POS1) to a deployed position (POS2) and vice versa. The step (10) includes a mechanical deployment system (30) connected to the step (15) and to the sliding door (5), said deployment system (30) being activated by a movement of said door (5) to move said step (15) between the deployed position (POS2) and the retracted position (POS1), said step (10) including a safety device (80) to disengage said door (5) and said step (15) in the event of said step (15) becoming blocked.