Weight Stack Load Cell Sensing for Accurate Exercise Force Tracking

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Solution Overview

Problem

Existing sensor-weight systems for exercise machines suffer from inaccurate weight measurements due to uneven deformation of protrusions, incorrect attachment, and potential cable damage, lacking durability and reliability.

Innovation Solution

A sensor-weight system integrating a load cell and three-axis accelerometer directly connected to the weight sword, with a robust housing and communication unit, providing precise force and movement monitoring, and real-time feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If protrusions are used to detect weight by bending, then weight measurement is enabled, but measurement accuracy deteriorates due to uneven deformation and wear

Engineering Contradiction:
Improveweight measurement accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts the measurement function from the mechanical protrusions and relocates it to a dedicated load cell sensor. The load cell is integrated into the weight sword, separating the sensing function from the mechanical cable attachment system, thereby eliminating the inaccuracies caused by protrusion deformation and wear.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The load cell acts as an intermediary between the cable and the weight sword, providing accurate force measurement without requiring direct mechanical deformation of the cable or protrusions. This intermediary sensor converts mechanical force into electrical signals for precise weight detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If exercise tracker is attached to cable for monitoring, then workout data collection is enabled, but cable damage occurs due to deformation required for attachment

Engineering Contradiction:
Improveworkout data collectionVSAvoidcable integrity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent extracts the sensor system from the cable and relocates it to the weight sword. By removing the exercise tracker from the cable and integrating a load cell into the weight sword instead, the cable is no longer subjected to attachment-related deformation and damage.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The load cell integrated into the weight sword serves as an intermediary that enables workout data collection without involving the cable in the sensing mechanism. This eliminates the need to attach sensors directly to the cable, preserving cable integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If load cell is integrated with weight sword and cable, then measurement accuracy is improved, but device complexity increases

Engineering Contradiction:
Improveforce measurement accuracyVSAvoidsystem integration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the load cell directly with the weight sword structure, integrating the sensing function into an existing component rather than adding a separate attached device. This consolidation reduces the number of separate parts and simplifies the overall system while maintaining measurement accuracy.

Inventive Principle:
Principle #5Merging (Combining)

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

Ensures accurate and reliable weight measurement, durability, and enhanced user experience through real-time feedback and seamless integration with exercise machines.

Implementation Method 1

a load cell, preferably a strain gauge load cell... The load cell represents a connecting element between the weight sword and the cable... the force is always directed through the load cell for enhanced accuracy

Methodology Applied
Scientific EffectLoad cell measurement: Piezoresistive Effect

Implementation Method 2

a three-axis accelerometer... allows for comprehensive monitoring of both static and dynamic loads, as well as the direction and speed of movements

Methodology Applied
Scientific EffectAccelerometer detection: Accelerometer

Data Source

PatentEP4653061A1A sensor-weight system for an exercise machine
Publication Date: 2025.11.26 ATLETICA DEUTSCHLAND GMBH
  • EP4653061A1 patent drawingFigure 1~2
  • EP4653061A1 patent drawingFigure 3~4
  • EP4653061A1 patent drawingFigure 5~6

AI summary

The present application relates to a sensor-weight system for an exercise machine. The system comprises a load cell, a three-axis accelerometer, a battery, a housing, a communication unit, a data processing unit, and a weight stack with multiple weights. The load cell interconnects a cable with the weight sword of the weight stack, allowing precise measurement of the user's exerted force during exercise.