Power Tool Torque Sensor Manual Tightening Control

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Solution Overview

Problem

Existing power tool systems for tightening rotatable fastening elements are time-consuming and inflexible, requiring advance planning for each torque value, limiting unscheduled work on construction sites with multiple fastening elements of different torque values.

Innovation Solution

A power tool system with an electric motor, torque sensor, and integrated control unit that allows for manual presetting and display of desired torque values, enabling faster and more flexible operation by automatically switching off the motor when the value is approached, followed by manual final tightening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a keyboard or flip-setting device is used to preset torque values, then the desired torque value can be set accurately, but the operation becomes time-consuming and requires advance planning for each fastening element

Engineering Contradiction:
Improvetorque value setting accuracyVSAvoidtime for presetting torque values
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The torque sensor and control unit automatically detect the torque value during manual tightening and display it on the display device, eliminating the need for manual presetting via keyboard or flip-setting device. The system serves itself by automatically reading and displaying the torque value, saving time while maintaining accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical/electronic presetting mechanisms (keyboard, flip-setting device) with an automatic torque detection system using a torque sensor that reads the actual torque value during operation and displays it, eliminating the need for advance mechanical presetting.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If torque values are preset for each fastening element, then the tightening can be controlled accurately, but the flexibility to work unscheduled on construction sites is reduced

Engineering Contradiction:
Improvetightening control accuracyVSAvoidflexibility for unscheduled work
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The system transitions from static pre-set torque values to dynamic real-time torque detection. The torque sensor continuously monitors and displays the actual torque value during tightening operations, allowing the worker to adapt to different fastening elements on construction sites without prior planning, while maintaining precise control through real-time feedback.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If manual tightening is used for final tightening, then the desired torque value can be reached precisely, but the overall tightening process becomes slower

Engineering Contradiction:
Improvefinal tightening precisionVSAvoidtightening operation speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The torque sensor and display device provide continuous real-time feedback during the entire tightening process, from initial motor-driven tightening to final manual tightening. This continuous monitoring allows the worker to seamlessly transition between motor operation and manual tightening without interruption, maintaining both speed and precision throughout the entire process.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2217406B1A power tool and a method for use of the power tool
Publication Date: 2016.07.20 ATLAS COPCO IND TECHNIQUE AB INTELLECTUAL PROPERTY DEPARTMENT
  • EP2217406B1 patent drawingFigure 1
  • EP2217406B1 patent drawingFigure 2
  • EP2217406B1 patent drawingFigure 3

AI summary

The present invention relates to a power tool (2, 30, 32), comprising an electric motor (6) including a rotor (8) and a stator (10), a torque sensor (16) for measuring the torque value during tightening of rotatable fastening elements, and an operation control unit (18), integrated in or in communication with the power tool. The power tool (2, 30, 32) comprises means (26, 28) for preventing rotation of the rotor (8). The present invention also relates to a method for tightening rotatable fastening elements by use of the power tool.