Cylindrical Workpiece Locking Ring With Low-Torsion Actuation

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Solution Overview

Problem

Existing locking devices for symmetric cylindrical bodies face issues with excessive torque during tightening, leading to potential breakage of the central portion with a reduced cross-section, and often result in suboptimal performance and durability.

Innovation Solution

A locking device with a threaded actuation element featuring a smooth head portion and a single threaded tail portion, eliminating the double thread design, which reduces the risk of breakage by minimizing torsional stress when high torque is applied.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a double-threaded actuation element is used to enable bidirectional rotation for jaw engagement and disengagement, then the locking device achieves reversible functionality, but the central portion with reduced cross-section is subjected to excessive torsion during tightening, risking breakage

Engineering Contradiction:
Improvereversible locking functionalityVSAvoidtorsional strength of central portion
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The actuation element is segmented into three distinct portions: a smooth head portion for engagement, a central portion with reduced cross-section for tab accommodation, and a threaded tail portion for screwing. This segmentation allows each portion to be optimized for its specific function, with the threaded tail portion bearing the tightening torque while the smooth head portion enables rotation without transmitting excessive torsion to the vulnerable central portion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The smooth head portion acts as an intermediary between the rotation operation and the central portion. By providing a smooth surface that translates rotational motion without transmitting high torsional stresses, it protects the central portion with reduced cross-section from breakage while still enabling the bidirectional rotation needed for reversible locking.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the threaded actuation element is tightened with high torque to ensure secure locking, then the locking reliability is improved, but the central portion with reduced cross-section is at risk of breakage

Engineering Contradiction:
Improvelocking reliabilityVSAvoidtorsional strength of central portion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The actuation element is segmented into three distinct portions: a smooth head portion for engagement, a central portion with reduced cross-section for tab accommodation, and a threaded tail portion for screwing. This segmentation allows each portion to be optimized for its specific function, with the threaded tail portion bearing the tightening torque while the smooth head portion enables rotation without transmitting excessive torsion to the vulnerable central portion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design converts the potentially harmful effect of high tightening torque into a beneficial outcome by directing the torque application point to the threaded tail portion, which is structurally designed to withstand it. The smooth head portion and central portion are shielded from the harmful torsional stresses, allowing high torque tightening to achieve reliable locking without compromising the central portion's integrity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Adaptability or versatility

If a double-threaded actuation element is used to enable bidirectional rotation for jaw engagement and disengagement, then the locking device achieves reversible functionality, but the device complexity increases due to the dual threading requirement

Engineering Contradiction:
Improvereversible locking functionalityVSAvoidthreaded actuation element structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The actuation element is segmented into three distinct portions: a smooth head portion for engagement, a central portion with reduced cross-section for tab accommodation, and a threaded tail portion for screwing. This segmentation simplifies the overall design by eliminating the need for complex double threading, as only a single threaded portion is required while still achieving bidirectional rotation capability through the smooth head portion.

Inventive Principle:
Principle #1Segmentation

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 solution allows safe tightening without risking breakage and maintains performance, effectiveness, and durability comparable to or exceeding that of existing devices, while preventing excessive torsion on the central portion with a reduced cross-section.

Implementation Method 1

a threaded actuation element (16), which is screwed into a corresponding hole (17) in the base plate (12); By rotating the threaded actuation element, the rotation of the jaw supporting ring (15) is achieved

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

a cam mechanism (13) for the movement in a radial direction of a plurality of movable engagement jaws (14), said cam mechanism comprising a rotatable jaw supporting ring (15)

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP3493944B1Locking device for a symmetric cylindrical body fixing a semi-finished product to a workstation
Publication Date: 2022.11.02 REM IND SRL
  • EP3493944B1 patent drawingFigure 1~2
  • EP3493944B1 patent drawingFigure 3

AI summary

A locking device (10) for a symmetric cylindrical body fixing a semi- finished product to a workstation, which comprises an annular locking body with movable jaws (11), with a cam mechanism (13) for moving in a radial direction a plurality of movable engagement jaws (14), - the cam mechanism (13) comprising a rotatable jaw supporting ring (15), which is adapted to be rotated by means of a threaded actuation element (16), which is screwed into a corresponding hole (17) in the base plate (12), designed to act on an operation tab (18) which extends from the rotatable jaw supporting ring (15). The threaded actuation element (16) comprises: - a smooth head portion (19), - a central portion (21) having a reduced cross-section, which is adapted to accommodate the operation tab (18) of the jaw supporting ring (15), - and a threaded tail portion (22).