Interference Fit Tightening Member for Accurate Torque Transmission

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Solution Overview

Problem

Existing screw-fastener tightening technologies rely on calibrated operators and are structurally incapable of delivering high tightening forces or accurate torque transmission, especially when materials like concrete or wood are involved, leading to issues with vibration and material creep.

Innovation Solution

A method and member utilizing interference between tightly fitting surfaces with controlled tolerances and stresses to transmit a predetermined tightening torque, allowing for reliable and accurate force transmission, and enabling subsequent tightening operations without requiring qualified personnel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If standardized tightening means with easily deforming material are used, then the device can transmit limited torque, but it is structurally incapable of delivering high tightening forces

Engineering Contradiction:

Improvetightening forceVSAvoidstructural strength

Core Design Contradiction:

ForceVSStrength

Solution Approach 1:

The patent changes the material parameter from easily deforming material to rigid material, fundamentally altering the structural capability to transmit high torque and delivering high tightening forces without structural failure

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The tightening member uses composite construction with a rigid outer shell and internal reinforcement elements, combining different material properties to achieve both high strength and controlled deformation characteristics for accurate torque transmission

Inventive Principle:

Principle #40Composite materials

2Measurement precision

If calibrated tightening members are used, then accurate torque transmission can be achieved, but action by qualified personnel is required

Engineering Contradiction:

Improvetorque transmission accuracyVSAvoidoperation simplicity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The tightening member incorporates self-calibrating features where the rigid structure and internal mechanisms automatically ensure accurate torque transmission without requiring external calibration or qualified personnel intervention

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the need for human-calibrated systems with a mechanically self-regulating system that uses rigid structural elements and controlled deformation zones to inherently ensure accurate torque transmission

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If destructive forces are transmitted to the screw-fastener element, then the predetermined torque is reached, but the element is damaged and cannot be tightened again

Engineering Contradiction:

Improvetorque control reliabilityVSAvoidre-tightening capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The tightening member is segmented into a rigid body and a controlled deformation element, where the deformation element absorbs the limiting action through controlled elastic deformation rather than destructive failure, preserving the screw-fastener element for future use

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The rigid structure incorporates predetermined deformation zones that act as cushioning elements, absorbing excess energy through controlled elastic deformation before it can cause destructive damage to the screw-fastener element

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 ensures reliable and accurate transmission of a predetermined tightening torque, allowing for successive tightening operations and maintaining screw-fastener integrity, even in varying conditions, without the need for qualified operators and avoiding overdimensioning.

Implementation Method 1

The coefficient of friction between the threads, which is data provided by the screw-fastener manufacturer

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS8753057B2Method and member for tightening threaded fasteners, and fixing and tightening device

Publication Date: 2014.06.17 GAY PIERRE

AI summary

This method of tightening a threaded fastener (6) to a predetermined torque comprises steps in which: axial and rotational coupling is begun, by surface shrinking to a tight fit, of the threaded fastener (6) to a tightening member (2) capable of turning the threaded fastener (6) and thereby tightening it, the tightening member (2) and the threaded fastener (6) being able, from an initial coupled configuration between the tightening member and the threaded fastener, to remain rotationally coupled at a rotary drive torque, transmitted by the tightening member to the threaded fastener, that is less than the predetermined tightening torque, and to be rotationally decoupled from each other at a rotary drive torque, transmitted by the tightening member to the threaded fastener, that is equal to the predetermined tightening torque; and from this initial coupled configuration, a rotary movement is applied to the tightening member (2) up to a rotary drive torque, transmitted by the tightening member (2) to the threaded fastener (6), that causes rotational decoupling of the tightening member (2) from the threaded fastener (6).