Inflatable Life Raft Bottom Elevation and Drainage
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Solution Overview
Problem
Existing inflatable life rafts face challenges in being self-draining, requiring high bollard pull for towing, and exposing occupants to direct seawater contact, which can lead to hyperthermia and increased manufacturing costs.
Innovation Solution
An inflatable floatable unit with a dual bottom layer configuration where the second bottom layer is inclined and connected at a centre point, elevating the bottom above sea level, reducing contact with seawater and towing resistance, and incorporating a self-draining mechanism with a one-way valve and anti-vacuum system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the bottom of the life raft is made to contact the seawater for stability, then the life raft is stable in water, but the occupants are exposed to direct seawater contact which can lead to hyperthermia
Solution Approach 1:
The patent introduces a vertical dimension by elevating the bottom of the life raft above the water line using an extended bottom structure. This dimensional change allows the bottom to provide stability while remaining above the seawater, preventing direct contact between occupants and cold water that causes hyperthermia.
2Object-affected harmful factors
If the bottom of the life raft is elevated above sea level to prevent seawater contact, then hyperthermia risk is reduced, but the towing force or bollard pull required increases
Solution Approach 1:
The patent applies curvature to the extended bottom structure, forming a streamlined, curved surface that reduces hydrodynamic resistance. This curved geometry allows the elevated bottom to cut through water more efficiently during towing, significantly reducing the bollard pull force required compared to a flat or angular extended bottom structure.
3Ease of manufacture
If a single bottom layer is used to simplify manufacturing, then manufacturing cost is reduced, but the life raft cannot be self-draining and requires high bollard pull
Solution Approach 1:
The patent divides the bottom structure into multiple segmented layers (first bottom layer and second bottom layer) with the second layer extending further to form the elevated drainage path. This segmentation enables the bottom to perform multiple functions: providing structural support, creating self-draining capability through the elevated section, and reducing towing resistance through the curved geometry, all while remaining manufacturable.
4Reliability
If the bottom is extended to provide self-draining capability, then the life raft becomes self-draining, but the structure becomes more complex and manufacturing cost increases
Solution Approach 1:
The patent merges the drainage function with the existing bottom structure by extending the second bottom layer to form an elevated section that naturally channels water outward. This integrated design eliminates the need for separate drainage pumps or complex mechanical systems, achieving self-draining capability through the geometric configuration of the bottom layers themselves.
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 solution provides a self-draining, low-bollard-pull inflatable unit that minimizes hyperthermia risk, reduces towing force requirements, and meets statutory requirements while being cost-effective to manufacture.
Implementation Method 1
the first and second bottom layers having a mutual distance at the centre point being less than the distance between the upper and lower sides of the first flotation tube layer so that at least the second bottom layer has an inclined extension from the lower side of the first flotation tube layer to the centre point
Implementation Method 2
by inclining the second bottom layer, the overall resistance coefficient (i.e. Cd) of the floatable unit in the water is reduced considerably in relation to other floatable units having an elevated bottom
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to an inflatable floatable unit (1) for life-saving equipment comprising at least a first inflatable flotation tube layer (2) having an upper (3) and a lower (4) side with a distance between the upper side and the lower side (3, 4), a second inflatable flotation tube layer (5) having an upper (6) and a lower side (7) with a distance between the upper and lower sides (6, 7), the first and second flotation tube layers (2, 5) being adapted to be arranged substantially above each other so that the upper side of the first tube layer is opposite the lower side of the second tube layer, the inflatable tube layers extending circumferentially for providing a substantially ring-shaped area, and a bottom element (8) adapted to provide a bottom to the substantially ring-shaped area.