Adjustable Self-Tailing Winch for Rapid Rope Release

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Solution Overview

Problem

Nautical winches with self-tailing devices struggle to allow quick and easy partial or complete release of the rope under tension, requiring user experience and posing safety risks, especially in competitive sailing where rapid adjustments are necessary.

Innovation Solution

A nautical winch with an adjustable self-tailing device featuring a movable half-pulley that can be positioned to increase the wheelbase between half-pulleys, allowing controlled release of the rope without disengaging from the self-tailing device, facilitated by a user-activated adjustment mechanism and counteraction springs for temporary opening and automatic closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a self-tailing device is used to lock the rope on the winch, then the rope is securely held and prevents unwinding, but the rope cannot be quickly or easily released even partially without disengaging from the self-tailing device

Engineering Contradiction:
Improverope locking reliabilityVSAvoidrope release ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The self-tailing device is designed with a mobile half-pulley that can be moved along the longitudinal axis of the rotor body. By moving the mobile half-pulley away from the fixed half-pulley, the wheelbase increases and the rope is released to slide freely. By moving the mobile half-pulley closer, the wheelbase decreases and the rope is clamped again. This dynamic adjustment allows rapid transition between locked and released states without disengaging from the device.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the wheelbase parameter (distance between half-pulleys) to control rope movement. When the wheelbase is small, the rope is clamped securely. When the wheelbase is increased by moving the mobile half-pulley, the rope is released to slide. This parameter change enables rapid control of rope release while maintaining security when needed.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the self-tailing device maintains a fixed small wheelbase for secure rope clamping, then the rope is reliably held, but the device cannot accommodate different rope diameters or allow rapid release

Engineering Contradiction:
Improverope clamping securityVSAvoidrope diameter adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The mobile half-pulley can be positioned at different locations along the longitudinal axis, dynamically adjusting the wheelbase to accommodate different rope diameters. For smaller ropes, the half-pulleys are positioned closer together; for larger ropes, they are positioned farther apart. This provides adaptability while maintaining secure clamping for each rope type.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The self-tailing device serves multiple functions: it can securely clamp various rope diameters by adjusting the mobile half-pulley position, and it can rapidly release the rope when needed. The single device structure accommodates both security and adaptability requirements through the movable half-pulley mechanism.

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

3Ease of operation

If the mobile half-pulley is allowed to move freely along the longitudinal axis, then rapid rope release is enabled, but uncontrolled movement or accidental opening may occur

Engineering Contradiction:
Improverope release speedVSAvoiddevice stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The mobile half-pulley is equipped with a spring that automatically returns it to its initial position (close to the fixed half-pulley) after the rope release operation. The spring ensures the device self-closes and maintains the secure clamping state without requiring manual intervention, preventing accidental opening while enabling rapid controlled release when the user activates the mechanism.

Inventive Principle:
Principle #25Self-service

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 and safe partial or complete release of the rope under tension, enhancing operational efficiency and safety by allowing controlled unwinding without disengaging from the self-tailing device, suitable for competitive sailing and other rope-lifting applications.

Implementation Method 1

A plurality of preloaded springs thrusts the second half-pulley against the first half-pulley to clamp the rope in the throat of the self-tailing device

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

Often the surfaces of the two half-pulleys that engage the rope are knurled to maximise the hold of the self-tailing device on the rope itself

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2616380B1Winch provided with adjustable self-tailing and relative operation
Publication Date: 2019.11.06 HARKEN ITAL
  • EP2616380B1 patent drawingFigure 1~2
  • EP2616380B1 patent drawingFigure 3~4
  • EP2616380B1 patent drawingFigure 5~6

AI summary

The invention describes a winch (1) for nautical use or for devices for lifting and lowering on a rope, comprising a fixed stator body (2) and a rotor body (3) fixedly connected to the stator body. The rotor body is able to rotate around a longitudinal axis(a-l) to wind a rope on its outer surface. The winch is provided with a self -tailing device (6) in turn comprising two half -pulleys (61, 62 ), a lower half -pulley (61) and an upper half -pulley (62 ), mounted opposite one another and coaxial to the rotor body. The two half -pulleys, at the upper portion of the outer surface of the rotor body, define a circumferential throat (63) intended to at least partially house a winding of the rope. One half -pulley is fixed with respect to the rotor body and the other half -pulley is moveable parallel to the longitudinal axis to vary the dimensions of the circumferential throat. Advantageously, the winch comprises a device (8 -11) for adjusting the position of the mobile half -pulley along the longitudinal axis; the adjustment device is able to be activated by the user in real time and in all conditions of use of the winch.