Retractable Clamping Device Key for Portable Tool Operation

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Solution Overview

Problem

Existing clamping devices for portable tools, such as chain saws, require external tools for tightening and loosening, which can be inconvenient, especially outdoors, and often require complex maneuvers that may not be user-friendly.

Innovation Solution

A clamping device with a rotating key and connecting mechanism that allows tilting around a perpendicular axis, enabling screwing or unscrewing without external tools, and featuring a range of angular displacement over 170°, with a fork-shaped key head and annular groove design for secure engagement and disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a screw-nut system with external tools is used for tightening, then the clamping force can be applied, but the operation becomes complex and requires external tools that may not be available

Engineering Contradiction:
Improvetightening operationVSAvoidoperation complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The key is merged with the clamping member through a connecting device, integrating the driving function and positioning function into a single component. This eliminates the need for separate external tools and simplifies the operation while maintaining the clamping capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The clamping device becomes self-sufficient by incorporating the key and connecting device that enable tightening and loosening operations without external tools. The device serves itself by having all necessary components integrated into the clamping assembly.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If the key is permanently fixed to the clamping member, then the tightening operation is simplified, but the key interferes with the use of the tool when not in use

Engineering Contradiction:
Improvetightening operationVSAvoidtool usability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The connecting device allows the key to dynamically change its position relative to the clamping member. The key can be tilted between a working position for tightening operations and a rest position against the housing for normal tool use, providing both ease of operation and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The key is given the ability to move in a tilting motion around an axis perpendicular to the screwing axis, adding a rotational degree of freedom. This allows the key to be positioned out of the way when not in use while remaining accessible when needed.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If the key is made tiltable around the clamping member, then the key can be stored in rest position, but the connecting device becomes more complex

Engineering Contradiction:
Improvekey positioningVSAvoidconnecting device
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connecting device acts as an intermediary mechanism between the key and the clamping member, enabling the tilting motion while maintaining the driving connection. This intermediary structure facilitates the dimensional change without requiring complex mechanical linkages.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If the key can rotate freely over a large angular range, then the key can be positioned in rest position, but the engagement mechanism becomes more complex

Engineering Contradiction:
Improveangular displacementVSAvoidengagement mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connecting device employs asymmetric engagement features including a drive finger with a specific profile and corresponding notches on the clamping member. This asymmetric design enables the large angular displacement range while maintaining secure engagement during tightening operations.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP1961531B1Tightening device with a retractable manoeuvring arm and apparatus including such a device
Publication Date: 2013.09.18 PELLENC SA
  • EP1961531B1 patent drawingFigure 1
  • EP1961531B1 patent drawingFigure 2
  • EP1961531B1 patent drawingFigure 3~6

AI summary

A screw-nut type clamping device comprising a clamping member (7) capable of being driven into rotation and a wrench (11) for driving this clamping member (7), having an operating arm (17), this wrench (11) and the clamping member (7) being joined by a linkage device (9) arranged so that the wrench (11) can pivot relative to the clamping member (7) about a pivot axis (Y-Y') substantially perpendicular to the screw axis (X-X') of said clamping member (7) so as to allow its placement in a rest position substantially perpendicular to said screw axis and can drive the clamping member (7) into rotation about said screw axis (X-X'), or rotate freely relative to the clamping member (7), about said screw axis (X-X'), over an angular deflection range (α) of at least 170°.