Self-locking Abseiling Device Handle Cam Mechanism

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Solution Overview

Problem

Users face difficulty in maintaining the handle just below the threshold position in self-locking descenders, leading to premature disengagement of the mechanical connection between the handle and cam, especially on slight inclines, which increases the risk of accidents due to continuous button pressing to deactivate the anti-panic function.

Innovation Solution

A self-locking descender design with a cam and handle mechanism that includes a first pin and stop arrangement for controlled disengagement, where the handle's movement causes the cam to transition from a blocking to a sliding position, and a second pin and stop mechanism with a spring to provide a minimal force indication when approaching the threshold position, ensuring automatic disengagement and user awareness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mechanical connection between the handle and cam is maintained continuously, then the user can maintain control during descent, but the user experiences difficulty in maintaining the handle at the correct position and may press the button continuously increasing accident risk

Engineering Contradiction:
ImprovesafetyVSAvoidhandle position control
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The spring-loaded second stop provides preliminary mechanical engagement before the threshold position is reached, creating a tactile warning that prepares the user for upcoming disengagement and prevents accidental button pressing

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The second stop acts as a mechanical feedback mechanism that provides tactile information to the user about the handle's position relative to the threshold, enabling the user to maintain proper control without continuous button pressing

Inventive Principle:
Principle #23Feedback

2Extent of automation

If the mechanical connection disengages automatically at the threshold position, then the anti-panic function is activated, but the user may not be aware of approaching the threshold position in time

Engineering Contradiction:
Improveautomatic disengagementVSAvoiduser awareness of threshold position
Core Design Contradiction:
Extent of automationVSLoss of information

Solution Approach 1:

The second stop provides mechanical feedback to the user before automatic disengagement occurs, maintaining user awareness of the threshold position while preserving automated safety disengagement

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The second stop engages preliminarily before the threshold position to warn the user, allowing the user to take corrective action before automatic disengagement occurs

Inventive Principle:
Principle #10Preliminary action

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 design facilitates controlled and automatic disengagement of the mechanical connection, allowing users to maintain the connection without continuous button pressing, enhancing safety by providing a tactile cue for approaching the threshold position, thus reducing the risk of accidents during descents on various slopes.

Implementation Method 1

a second stop fixed to the handle to cooperate with the second pin, the second stop being movable relative to the handle by means of a spring moving the second stop to a first position

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3552668B1Self-locking abseiling device with releasable handle
Publication Date: 2022.04.06 ZEDEL CORP
  • EP3552668B1 patent drawingFigure 1
  • EP3552668B1 patent drawingFigure 2
  • EP3552668B1 patent drawingFigure 3

AI summary

The descender comprises a handle (5) and a cam that move between rope-locking (1) and sliding positions. The cam defines a first stop (11) and a second pin (16). The handle (5) has a first pin (10) that contacts the first stop (11) to form a first mechanical linkage, and a second stop (15) that contacts the second pin (16). Movement of the handle (5) causes the cam to move between the locking and sliding positions. In a threshold position of the handle (5), the first mechanical linkage is broken, and the cam returns to the locking position. The second stop (15) is movable relative to the handle (5) by means of a spring (9). During movement of the handle (5), the second pin (16) contacts the second stop (15) before the handle (5) compresses a spring (9) and reaches the threshold position.