Flexible Ballast Keel for Inflatable Structure Stability

Solution Overview

Problem

Inflatable structures of cylindrical shape lack inherent stability when floating on water and require ballast for stability, which can be inconvenient due to bulk and weight, especially during transport and on classic motor boats.

Innovation Solution

A stabilizing device with flexible ballasts extending laterally along an elongated inflatable structure, featuring a vent orifice at the front and a scoop system at the rear, connected by a pipe to equalize water pressure and act as a keel, similar to a catamaran hull, providing stability without the need for additional floats.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If ballast is added to stabilize the inflatable structure, then stability is improved, but bulk and weight increase making transport inconvenient

Engineering Contradiction:

ImprovestabilityVSAvoidbulk

Core Design Contradiction:

Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The ballast system transitions from a static fixed weight to a dynamic system that automatically adjusts water intake based on operational conditions. The flexible ballast with scoop and vent allows water to be taken in or discharged automatically, providing stability only when needed during operation while remaining compact during transport.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The physical state of the ballast changes from empty (transport mode) to water-filled (operation mode). The flexible ballast structure utilizes parameter changes in water level and pressure to provide stability during operation, while returning to a compact state during transport, effectively resolving the contradiction between stability and bulk.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If ballast is added to stabilize the inflatable structure, then stability is improved, but weight increases

Engineering Contradiction:

ImprovestabilityVSAvoidweight

Core Design Contradiction:

Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The ballast system transitions from a static fixed weight to a dynamic system that automatically adjusts water intake based on operational conditions. The flexible ballast with scoop and vent allows water to be taken in or discharged automatically, providing stability only when needed during operation while remaining compact during transport.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The physical state of the ballast changes from empty (transport mode) to water-filled (operation mode). The flexible ballast structure utilizes parameter changes in water level and pressure to provide stability during operation, while returning to a compact state during transport, effectively resolving the contradiction between stability and weight.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If a rigid keel structure is used for stability, then stability is improved, but flexibility and ease of manufacture decrease

Engineering Contradiction:

ImprovestabilityVSAvoidease of manufacture

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The invention replaces rigid keel structures with flexible ballasts made from flexible watertight material. These flexible membranes can be easily manufactured and integrated into the inflatable structure, while still providing the necessary stability function when filled with water during operation.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The flexible ballast utilizes changes in water content and pressure to achieve stability, eliminating the need for rigid structures. The flexible material allows for easier manufacturing and integration while maintaining the stabilizing function through parameter changes rather than structural rigidity.

Inventive Principle:

Principle #35Parameter changes

4Stability of the object's composition

If ballast is added to stabilize the inflatable structure, then stability is improved, but device complexity increases

Engineering Contradiction:

ImprovestabilityVSAvoiddevice complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The ballast system is designed to operate automatically without external control. The scoop automatically takes in water when needed, and the vent automatically discharges water when the ballast is full. This self-regulating mechanism provides stability while minimizing the need for complex control systems, pumps, or manual intervention.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The complex control mechanisms (pumps, valves, sensors) are extracted and replaced with simple passive elements (scoop and vent). The stabilization function is achieved through the inherent physical properties of the scoop-vent system rather than complex active control, reducing device complexity while maintaining effectiveness.

Inventive Principle:

Principle #2Taking out (Extraction)

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

Enables rapid stabilization of the inflatable structure for safe trajectory following, similar to classic motor boats, by automatically filling with water and maintaining geometrical shape through non-return valves and flexible materials, enhancing stability during movement.

Implementation Method 1

a scoop system, located at the rear, with, between the rear ends of these ballasts, at the rear of the said scoop system, a pipe which links the cavities of the said ballasts

Methodology Applied

Scientific EffectWater flow:

Implementation Method 2

a pipe which links the cavities of the said ballasts in order to equalize the load and/or the total pressure of the water which reigns in the said cavities

Methodology Applied

Scientific EffectPressure equalization: Pascal's Law

Implementation Method 3

the junction between each equalizing pipe and the compartment of the corresponding ballast comprises a non-return valve in such a way as to place, at the level of the said equalizing pipes, elements which are capable of maintaining a geometrical shape

Methodology Applied

Scientific EffectNon-return valve mechanism: Valve

Implementation Method 4

The ballasts are provided in the form of elongated fenders which are integral with the inflatable structure, over at least a part of their length. The ballasts are made of a flexible watertight fabric

Methodology Applied

Scientific EffectFlexible watertight material:

Data Source

PatentUS9073612B2Device for stabilizing an inflatable structure

Publication Date: 2015.07.07 SURVITEC

AI summary

The device comprises at least one pair of flexible ballasts which extend laterally along the length of the inflatable structure and each comprise an orifice, acting as a vent, situated at the front, and a scoop system situated at the rear. Between the ballasts, at least one pipe connects the cavities of said ballasts to equalize their level of fill and the stagnation pressure of the water obtaining in said cavities when the inflatable structure is pulled along in the inflated state. This scoop system consists of a component moulded in a rigid or semirigid thermoplastic or is made of an assembly of cutouts from a flexible material of watertight fabric. This scoop system is bonded and/or welded to the ballast.