Gravity-Locking Hinge for Foldable Vehicle Bunks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hinge solutions for foldable vehicle bunks are inadequate in terms of assembly simplicity, disassembly ease, safety, and strength, particularly failing to maintain structural integrity during high forces in crash situations.

Innovation Solution

The hinge design features a circular axle member with flat portions that orientally fit into slots in the wall and bunk members, allowing gravity-assisted assembly and locking, with sloping wall portions for longitudinal guidance and enhanced crash strength through a closed loop connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional hinge solutions are used for foldable vehicle bunks, then assembly and disassembly processes become complex and time-consuming, but using simpler hinge designs reduces the strength and reliability of the connection

Engineering Contradiction:
Improveassembly simplicityVSAvoidhinge connection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The hinge is divided into separate components: a wall member with circular holes, a bunk member with slots, and an axle member with flat portions. This segmentation allows for simple gravity-assisted assembly while maintaining strong connections through the interlocking geometry of the components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The axle member features asymmetric flat portions that correspond to the slot orientations in the wall and bunk members. This asymmetric design creates a unique fitting relationship that ensures proper alignment and prevents accidental disengagement, while still allowing easy assembly through gravity.

Inventive Principle:
Principle #4Asymmetry

2Device complexity

If simple hinge designs are used to reduce manufacturing complexity and cost, then the strength of the hinge is reduced and becomes inadequate for crash situations

Engineering Contradiction:
Improvehinge design complexityVSAvoidhinge strength
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The slots in the wall and bunk members are pre-oriented at specific angles relative to each other. When the axle member is inserted, the flat portions automatically align with these pre-oriented slots, creating a locked configuration that provides strong crash resistance without complex fastening mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The hinge design merges the functions of alignment, locking, and rotation into a single integrated mechanism. The flat portions of the axle member serve both as alignment features during assembly and as locking elements during use, eliminating the need for separate fasteners or complex assembly procedures.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If the axle member is designed to be easily inserted and removed, then accidental disengagement may occur compromising safety, but if the connection is more secure, then disassembly becomes difficult

Engineering Contradiction:
Improvedisassembly easeVSAvoidaccidental disengagement risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The hinge design allows the bunk to serve itself during assembly. By tilting the bunk to a mounting position, gravity automatically guides the axle member into the circular holes through the slots, creating a locked connection without requiring tools or additional assembly steps. The same gravitational mechanism prevents accidental disengagement during normal use.

Inventive Principle:
Principle #25Self-service

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

This design simplifies assembly and disassembly, ensures safety by preventing accidental disengagement, and maintains structural integrity during crashes by locking the bunk securely to the wall, while allowing free rotation and easy folding.

Implementation Method 1

the flat portions being so oriented that the axle member will pass by gravity down into the circular holes

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

The bunk may preferably be longitudinally guided at mounting by sloping wall portions of the hinge

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2809860B1A method and a system for attaching a foldable bunk to a vertical wall in a vehicle
Publication Date: 2019.12.11 KLIPPAN SAFETY
  • EP2809860B1 patent drawingFigure 1~2
  • EP2809860B1 patent drawingFigure 3
  • EP2809860B1 patent drawingFigure 4~6

AI summary

A hinge (3) for attaching a foldable bunk (2) to a substantially vertical wall (1) in a vehicle comprises a wall member (4) attached to the wall, a bunk member (5) attached to the bunk, and a generally circular axle member (6) for rotatably connecting the bunk member to the wall member. The axle member (6) attached to the bunk member has flat portions (12) for enabling insertion of the axle member into circular holes (9) through slots (10) in the wall member (4). The slots (10) have a width corresponding to the smallest cross-section of the axle member created by the flat portions (12). The slots (10) and the flat portions (12) are so oriented that the bunk (2) with the bunk member (5) can connect to the wall member (4) by gravity in a certain position that it will not assume during use in the vehicle, whereas in all other positions the bunk member (5) is locked to the wall member (4) for relative rotative movements only.