Offshore Fairlead Impulse Control Ratchet Mechanism
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Solution Overview
Problem
Existing fairleads for offshore structures require continuous maintenance and power supply to keep the locking jaws in the open position for releasing the anchoring chains, which affects operating reliability and maintenance efficiency.
Innovation Solution
The fairlead incorporates impulse control means with pawl mechanisms that define stable open and closed positions for the jaw-shaped locking means, allowing the jaw to be controlled between these positions using a traction cable, eliminating the need for continuous actuation and ensuring reliable release and blocking of the anchoring chains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous actuation is used to keep locking jaws in the open position, then the anchoring element can be released, but the reliability decreases and maintenance requirements increase
Solution Approach 1:
The patent applies periodic action by using impulse control means that provide brief, periodic actuation signals to the operating means. Instead of continuous power supply and actuation, the system receives periodic impulse commands that trigger the jaw-shaped means to transition between locked and unlocked states. This eliminates the need for continuous maintenance of power supply systems and actuators, thereby improving reliability while reducing maintenance requirements.
Solution Approach 2:
The patent implements self-service through the ratchet mechanism that automatically maintains the jaw-shaped means in the unlocked position after a single impulse command. The ratchet means prevent the jaws from closing automatically, allowing the system to maintain its state without continuous external actuation. This self-maintaining mechanism eliminates the need for continuous power supply and reduces maintenance needs, directly addressing the reliability-maintenance contradiction.
2Ease of operation
If continuous power supply is provided to actuators, then the locking jaws can be kept in the open position, but the complexity and maintenance burden increase
Solution Approach 1:
The patent replaces continuous power supply with periodic impulse commands. The control means provide brief, periodic actuation signals that trigger the operating means to change the state of the jaw-shaped means. This periodic action eliminates the need for continuous power supply infrastructure, reducing system complexity while maintaining the ability to release the anchoring element on demand.
Solution Approach 2:
The patent substitutes the complex continuous mechanical actuation system with a simpler impulse-based control system combined with a ratchet mechanism. The ratchet means provide the continuous mechanical function of keeping the jaws open without requiring continuous mechanical actuation. This substitution dramatically reduces the complexity of the actuation system while preserving the ease of release functionality.
3Productivity
If impulse control with ratchet means is used, then maintenance requirements decrease, but the control mechanism complexity increases
Solution Approach 1:
The ratchet mechanism serves itself by automatically maintaining the jaw-shaped means in the unlocked position without requiring continuous external input. Once triggered by an impulse command, the ratchet means self-maintain the open state, eliminating the need for continuous monitoring or adjustment. This self-service capability dramatically improves maintenance efficiency, and the simplicity of the ratchet mechanism itself does not significantly increase overall system complexity.
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 solution enhances the reliability and maintenance efficiency of the fairlead by allowing the jaw-shaped locking means to maintain stable open and closed positions with a single impulse command, reducing the need for continuous power and actuation, thus improving the operational reliability of the anchoring system.
Implementation Method 1
The maneuvering means comprise ratchet means defining successive stable open and closed positions of the jaw-shaped means
Data Source
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AI summary
This fairlead (5) for guiding an anchoring element (3) of an offshore structure, such as a floating structure, at an anchoring point, of the type having means (11) for guiding the anchoring element (3) and means (12) for locking said anchoring element in position, having means (13) in the form of a locking jaw comprising two locking jaw elements that are movable by manoeuvring means actuated by control means, between a closed position preventing the anchoring element from moving in translation and an open position releasing the anchoring element, is characterized in that the control means are impulse-type control means, and in that the manoeuvring means comprise pawl means (16) that define successive stable open and closed positions of the means (13) in the form of a jaw.