Hinged Fuel Tank Cap with Spring Return

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Solution Overview

Problem

Current fuel tank caps are inadequate for ensuring secure closure, risk accidental loss during refueling, and do not meet regulatory standards for fuel containment, especially in the event of a vehicle overturn, while also complicating the refueling process and potentially allowing fuel theft.

Innovation Solution

A protective device for fuel tanks featuring a base with a rapid attachment system and sliders guided by helical springs, allowing automatic closure and venting, with a locking mechanism to prevent unauthorized access and ensure hermetic sealing, enabling easy refueling without manual handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional cap is used that requires manual screwing or bayonet mounting, then the cap can be securely attached to the tank mouth, but the user may forget to perform the final tightening operation or accidentally leave the cap at the refueling location

Engineering Contradiction:
Improvesecure closureVSAvoidmanual handling
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cap is equipped with a self-closing mechanism featuring a hinge connection between the cap and tank mouth, along with a spring element that automatically returns the cap to the closed position after refueling. This eliminates the need for manual tightening operations and prevents accidental loss of the cap.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The cap transitions from a static fixed position to a dynamic hinged connection, allowing it to move between open and closed positions. The spring element provides dynamic force to return the cap to its closed position, enabling automatic closure without manual intervention.

Inventive Principle:
Principle #15Dynamics

2Productivity

If manual operations are performed on components covered with slippery hydrocarbon sludge, then refueling can be completed, but the screwing and unscrewing operations become difficult to achieve

Engineering Contradiction:
Improverefueling completionVSAvoidscrewing operation
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The automatic closing mechanism eliminates manual screwing and unscrewing operations entirely. The cap opens and closes automatically through the hinged connection and spring mechanism, preventing contact with slippery hydrocarbon sludge and making the operation easier and cleaner.

Inventive Principle:
Principle #25Self-service

3Reliability

If a cap with spring is used to force automatic closing, then the cap closes automatically after refueling, but the refueling operations become difficult because one hand must hold the cap open while the other inserts or extracts the nozzle

Engineering Contradiction:
Improveautomatic closingVSAvoidrefueling operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cap assembly is divided into separate functional components: a base fixed to the tank, a hinged cap portion, and a spring element. This segmentation allows the cap to swing open easily during refueling without requiring manual holding, while the spring ensures automatic return to closed position afterward.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hinged connection provides dynamic movement capability, allowing the cap to swing open freely during refueling operations without resistance from the spring, then automatically return to closed position after the nozzle is removed. This resolves the conflict between easy operation during refueling and automatic closing afterward.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If a hinged pan held closed by spring is used inside the locking ring, then the cap can be opened automatically during refueling, but the contents of the tank become directly accessible permitting fuel theft

Engineering Contradiction:
Improveautomatic openingVSAvoidfuel theft
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The cap serves multiple functions simultaneously: it provides automatic opening during refueling, maintains hermetic sealing when closed, and prevents unauthorized access to fuel contents. The complete cap assembly with base, lid, and sealing elements creates a secure barrier that cannot be easily bypassed.

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

Solution Approach 2:

The invention uses a simple, robust cap assembly with basic hinge and spring mechanisms rather than complex electronic locking systems. This straightforward mechanical design is difficult to tamper with and provides adequate security against fuel theft while maintaining ease of operation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

5Device complexity

If traditional caps are used, then the structure is simple, but they do not meet regulatory standards for fuel containment in the event of vehicle overturn

Engineering Contradiction:
Improvestructural simplicityVSAvoidfuel containment
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The hinged cap with spring mechanism provides dynamic sealing capability that maintains hermetic closure under various vehicle orientations and during overturn events. The spring ensures the cap remains firmly closed against the tank mouth, preventing fuel leakage even when the vehicle is overturned.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention uses simple mechanical components (hinge, spring, gasket) rather than complex electronic or hydraulic systems to achieve reliable fuel containment. This straightforward design meets regulatory standards for fuel containment during overturn while maintaining structural simplicity and low cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 device ensures rapid and secure refueling, adheres to regulatory fuel containment standards, prevents fuel leakage, and integrates with anti-theft systems, while maintaining structural simplicity and low costs.

Implementation Method 1

The return action of the slider is controlled by a compression spring

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a sealing element arranged above the opening of the filler tube and adapted to prevent the leakage of fuel

Methodology Applied
Scientific EffectPhysical Containment: Physical Containment

Data Source

PatentEP2431209B1Protective device for the fuel tank of vehicles
Publication Date: 2013.05.29 LAGO ACCESSORI
  • EP2431209B1 patent drawingFigure 1~2
  • EP2431209B1 patent drawingFigure 3~4
  • EP2431209B1 patent drawingFigure 5~6

AI summary

A protective device (1) for the fuel tank of vehicles, constituted by a perforated base (2), which can be associated with the tank and with which a slider (14a, 14b) is associated, so that it can slide along an inclined plane and in contrast with at least one elastically deformable element, a lid (22) provided with seal means (27) being integral with this slider.