Canting Keel Worm Gear Locking for Sailing Vessel Stability

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Solution Overview

Problem

Modern sailing vessels face challenges in controlling the 'heeling' moment when sailing off or close-hauled, as they must always sail off the wind to avoid sail collapse, leading to limitations in direct downwind sailing and potential instability due to wind pressure.

Innovation Solution

A monohull sailing vessel with a mechanical canting keel and mast canting mechanism, utilizing double-enveloping worm gears and locking pins for precise angular control, along with a rigid rigging arrangement and adjustable ballast bulb, to maintain an even keel and counteract wind-induced heeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a mechanical canting keel system is implemented to control heeling moment, then stability and control precision are improved, but device complexity increases

Engineering Contradiction:
Improvevessel stabilityVSAvoidcanting mechanism complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The canting keel system is divided into separate functional components: the rotational housing that allows keel movement, the worm gear mechanism for controlled rotation, and the locking mechanism for position fixation. This segmentation enables independent optimization of each component while managing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The worm gear mechanism provides self-locking capability, where the gear teeth naturally prevent reverse motion without requiring additional active locking components. This self-service feature reduces the complexity of control systems while maintaining stable keel positioning against wind forces.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If a worm gear mechanism is used for keel rotation control, then positioning precision is improved, but energy loss increases

Engineering Contradiction:
Improvekeel angular position precisionVSAvoidmechanical energy loss
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The worm gear mechanism operates in periodic cycles of engagement and disengagement, where the worm tooth engages the gear tooth only during position changes, then disengages to allow free holding. This periodic action reduces continuous friction and energy loss while maintaining precise positioning capability.

Inventive Principle:
Principle #19Periodic action

3Reliability

If multiple locking mechanisms are added to secure keel and mast positions, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveposition locking reliabilityVSAvoidlocking system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking function is merged with the worm gear mechanism itself, where the gear teeth geometry provides both motion transmission and automatic locking. This integration eliminates the need for separate locking components, maintaining reliability while reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If the rotational housing extends below the hull in a cylindrical form, then ease of manufacture is improved, but hydrodynamic resistance increases

Engineering Contradiction:
Improverotational housing manufacturingVSAvoidwater resistance
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The rotational housing employs different geometries in different regions: a simple cylindrical form where manufacturing simplicity is prioritized, and streamlined contours in water-exposed areas to minimize hydrodynamic resistance. This local differentiation optimizes both manufacturing ease and hydrodynamic performance.

Inventive Principle:
Principle #3Local quality

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 allows for improved control of the vessel's heeling moment, enabling stable sailing off the wind and close-hauled, while eliminating risks of mast failure due to mal-adjusted backstays, and maintaining energy efficiency by self-locking the keel position.

Implementation Method 1

a first worm gear (310) and a first worm (320)... Said worm is preferably a double-enveloping worm

Methodology Applied
Scientific EffectWorm drive: Worm Drive

Implementation Method 2

said worm gear has multiple apertures into which locking pins are insertable to lock the worm gear in the angular position

Methodology Applied
Scientific EffectMechanical locking: Mechanical Fastener

Implementation Method 3

a rigid rigging arrangement formed of the mast and triangular stays which articulates with a rigging canting mechanism

Methodology Applied
Scientific EffectArticulation: Hinge

Data Source

PatentEP3297904B1Sailing vessel
Publication Date: 2022.06.01 STEENKAMP SARAH MAY
  • EP3297904B1 patent drawingFigure 1A
  • EP3297904B1 patent drawingFigure 1B
  • EP3297904B1 patent drawingFigure 1C

AI summary

A keel canting mechanism for a sailing vessel having a hull, a keel and a mast is disclosed. The mechanism comprises a worm gear co-axial with the longitudinal axis of the vessel about which the keel rotates during a canting movement. There is a double enveloping worm in mesh with the worm gear and means for driving the worm. The worm gear is fast with the keel and, when rotated by the worm, displaces the keel through a canting movement. The gear has a plurality of holes in it into which pins can be inserted to lock the gear, and hence the keel, in the position to which it has been moved by the worm.