Closing Finger Connector Cam Return for Easier Assembly

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Solution Overview

Problem

Existing connectors for rock climbing and mountaineering face assembly difficulties due to small, precise components, risk of dislodging during impacts, and high retaining forces required to maintain the connector in the open position, leading to ergonomic issues and potential malfunctions.

Innovation Solution

A connector design featuring an elastic axial compression means housed in a compression bore with a cam and sliding element that facilitates assembly and regular return movement, allowing for adjustable torque variation to balance security and ergonomics, using a sliding element with a larger cross-section and offset support line to mitigate assembly challenges and irregularities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an axial strip and compression spring mechanism is used for the elastic return device, then the connector can return to the closed position, but the assembly becomes difficult due to small cross-section components requiring precise and forceful insertion

Engineering Contradiction:
Improvereturn mechanism reliabilityVSAvoidassembly difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

A cam surface is introduced as an intermediary element between the compression spring and the closing finger. The cam surface with its offset support line provides a larger contact area and more favorable geometry for force transmission, eliminating the need for precise insertion of small components while maintaining the return function

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The support line is offset from the axis of rotation, changing the geometric parameters of the force application point. This offset creates a lever arm that provides both the return torque and reduces the required insertion force, making assembly easier while maintaining reliability

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the blade end is engaged in an off-center notch on the first end of the body, then the elastic return device can function, but the risk of dislodgement during impact increases

Engineering Contradiction:
Improveelastic return device reliabilityVSAvoidresistance to dislodgement during impact
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The cam surface merges the functions of the axial strip, the eccentric notch, and the impact resistance feature into a single integrated structure. The cam surface provides both the offset support for return motion and a broad contact area for impact resistance, eliminating the separate blade end and notch components

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If foreign bodies enter the eccentric notch, then the blade end may dislodge causing malfunction

Engineering Contradiction:
Improveelastic return device reliabilityVSAvoidsensitivity to foreign bodies
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The vulnerable eccentric notch feature is extracted and replaced by the cam surface design. The cam surface does not require the same precise fit and is less sensitive to foreign body intrusion, as the offset support line and broader contact area provide tolerance against contamination

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If the axial spring return mechanism is used to ensure sufficient holding torque, then the connector meets safety standards, but the spring return torque increases significantly at the beginning of opening, requiring high holding force from the user

Engineering Contradiction:
Improveholding torque in closed positionVSAvoidholding force required by user
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cam surface with offset support line creates a dynamic torque characteristic where the lever arm length varies with the opening angle. At the beginning of opening, the geometry provides a longer lever arm that reduces the required holding force, while still maintaining sufficient torque in the closed position to meet safety standards

Inventive Principle:
Principle #15Dynamics

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

Simplifies assembly, ensures reliable and regular return movement, reduces the need for high retaining forces, and allows for customizable torque laws to suit specific applications, enhancing both security and ergonomics.

Implementation Method 1

an elastic axial compression means, housed in a compression bore formed in a longitudinal section of one of the first body end or the first finger end

Methodology Applied
Scientific EffectElastic compression: Spring

Implementation Method 2

a cam formed on the other of the first body end or the first finger end, a sliding element with a front surface, which slides in translation along said longitudinal section of said same first body end or first finger end, the sliding element being stressed by the elastic axial compression means, which pushes it back, in a direction of thrust, by sliding support on the cam by its front surface along a line of support parallel to the axis of rotation of the closing finger and which is permanently offset towards the opening position of the closing finger relative to the direction of thrust passing through the axis of rotation of the closing finger

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP3510291B1Connector with closing finger and resilient return means resting slidingly together
Publication Date: 2021.10.20 ETAB LUDGER SIMOND
  • EP3510291B1 patent drawingFigure 1~2
  • EP3510291B1 patent drawingFigure 3~4
  • EP3510291B1 patent drawingFigure 5~6

AI summary

The invention relates to a connector comprising a connector body (1) having an opening (2) between a first body end (3) and a second body end (4) opposite one another, a closing finger (5) rotatably hinged by the first finger end (6) thereof between a closed position and an open position about a rotation axis (7), and a resilient return device (8) permanently biasing the closing finger (5) towards the closed position thereof. The resilient return device (8) comprises an axial compression spring (17), inserted into a compression bore (10) made in either the first body end (3) or the first finger end (6), a cam (19) arranged on the other one of the first body end (3) or the first finger end (6), and a sliding element (12), which slides axially about a section of said same first body end (3) or first finger end (6), the sliding element (12) being biased by the axial compression spring (17), which pushes same towards said first body end (3) or first finger end (6), the sliding element (12) resting slidingly on the cam (19) by a front surface (16) in an area (20) that is offset towards the inside of the connector relative to the axis of rotation (7) of the closing finger (5).