LED Clamping Force Indicator for Tightening Force Feedback

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Solution Overview

Problem

Not all tightening tools provide an integrated indication of tightening force, and even those that do, lack direct feedback on whether the applied force is excessive for a given part, limiting operator control.

Innovation Solution

An indicator device connected to a tightening tool, featuring a control unit that uses light assemblies with LEDs to provide visual feedback based on measured force values, indicating insufficient, acceptable, or excessive clamping force through distinct lighting patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a clamping tool incorporates a built-in indication device, then the operator can directly know whether the clamping force is excessive, but the device complexity increases and not all clamping tools have this capability

Engineering Contradiction:
Improveinformation on clamping force adequacyVSAvoidcomplexity of clamping tool
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent introduces an external indicator device that serves as an intermediary between the clamping tool's sensor and the operator. This separate device receives data from the clamping force sensor via a transmission unit and presents the information in a clear visual format, thereby providing information without requiring the clamping tool itself to be complex.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex mechanical indication systems with electronic sensing and optical display. The clamping force sensor electronically measures the force, transmits data digitally, and the indicator device uses light-emitting diodes to visually represent the clamping force status, simplifying the overall system while providing clear information.

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

2Loss of information

If a dial indicator is used to show tightening torque, then the operator can see the force value, but the operator cannot directly know whether the force is excessive or acceptable

Engineering Contradiction:
Improveinformation on force magnitudeVSAvoidease of interpreting force adequacy
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The patent uses color-coded light-emitting diodes (green, yellow, red) to indicate different clamping force zones. This visual color system immediately communicates to the operator whether the force is acceptable, excessive, or insufficient, eliminating the need to interpret numerical values and making the information instantly actionable.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The indicator device provides immediate visual feedback to the operator about the clamping force status. The control unit continuously monitors the sensor data and updates the LED display in real-time, giving the operator continuous feedback on whether to maintain, increase, or decrease the applied force.

Inventive Principle:
Principle #23Feedback

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

Enables operators to receive clear visual indications of clamping force levels, ensuring appropriate force application and preventing damage to parts.

Implementation Method 1

each of the light assemblies comprising at least one light-emitting diode

Methodology Applied
Scientific EffectLight-emitting diode: Light Emitting Diode

Data Source

PatentEP4177574B1Indicating device for a clamping tool with a clamping force sensor
Publication Date: 2024.05.29 NORELEM
  • EP4177574B1 patent drawingFigure 1
  • EP4177574B1 patent drawingFigure 2
  • EP4177574B1 patent drawingFigure 3

AI summary

The invention relates to an indicator device (10) configured to be connected to a clamping tool (1), the clamping tool (1) comprising a clamping force sensor (2) capable of measuring a clamping force (F) applied to a workpiece and a transmission unit (3) configured to transmit a signal encoding a value (V) measured by the clamping force sensor (2). The indicator device comprises: a first light assembly (41), a second light assembly (44), and a third light assembly (46), each of the light assemblies comprising at least one light-emitting diode; and a control unit (30) configured to receive the signal transmitted by the transmission unit (3), and to control the illumination of each of the light assemblies (41, 44, 46).