Treadmill Stiffness Adjustment via Adjustable Stop Wall

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Solution Overview

Problem

Existing fitness machines, particularly treadmills, lack a sufficient range of adjustability in stiffness settings, making it difficult for users to customize the level of shock absorption, and often require dedicated equipment for softer settings, increasing costs for facilities.

Innovation Solution

A system for adjusting the stiffness of a treadmill's running deck using a bracket, resilient bodies, and an adjustment device that allows for independent or simultaneous adjustment of stop walls, enabling a full range of stiffness settings from stiffer to very-soft, achieved through a combination of bending and compressive resistance phases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing fitness machines use fixed stiffness settings, then manufacturing and operation are simple, but adaptability for different user needs is poor

Engineering Contradiction:
Improvestiffness adjustabilityVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic stiffness adjustment by allowing the resilient body to transition between different operational phases (bending phase and compressive phase) through adjustable stop wall positioning. This enables the system to adapt its stiffness characteristics during operation rather than being fixed, resolving the contradiction between adaptability and complexity by providing variable stiffness through a controlled mechanical adjustment mechanism.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameters of the resilient body system by adjusting the stop wall position to modify the effective length and stiffness characteristics. This allows the same resilient body to provide different stiffness levels (from stiffer to very-soft settings) by changing geometric parameters, thereby improving adaptability without requiring multiple different components.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If facilities purchase multiple dedicated equipment for different stiffness settings, then adaptability is improved, but cost increases

Engineering Contradiction:
Improvestiffness rangeVSAvoidequipment quantity
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent makes a single fitness machine universally applicable across multiple stiffness settings by incorporating an adjustable stop wall mechanism. This allows one machine to perform the function of multiple dedicated machines with different fixed stiffness settings, thereby improving adaptability while reducing the quantity of equipment needed in facilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

By enabling dynamic adjustment of stiffness settings within a single machine, the system eliminates the need for multiple static machines. The resilient body can be reconfigured between bending-dominant and compression-dominant phases through stop wall positioning, providing a full range of stiffness settings from one universal device.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If resilient body length is increased for softer settings, then shock absorption is improved, but structural space requirements increase

Engineering Contradiction:
Improveshock absorption levelVSAvoidresilient body length
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The patent dynamically controls the effective length of the resilient body through adjustable stop walls rather than using physically longer components. By positioning the stop wall at different locations, the system achieves variable effective lengths (and thus variable shock absorption) without requiring the resilient body to be permanently extended, thereby maintaining compact structural space requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the effective operational parameters of the resilient body by adjusting stop wall positions rather than physically altering the resilient body dimensions. This allows the same resilient body to provide different shock absorption levels (softer to stiffer settings) through parameter adjustment, avoiding the need for increased physical length.

Inventive Principle:
Principle #35Parameter changes

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 customizable shock absorption with a wide range of stiffness settings, improving user experience and reducing the need for additional equipment, thereby enhancing user comfort and facility cost-effectiveness.

Implementation Method 1

a resilient body that resists movement of the running deck towards the base in a height direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4427821B1Systems and methods for adjusting a stiffness of fitness machines
Publication Date: 2026.04.01 LIFE FITNESS LLC
  • EP4427821B1 patent drawingFigure 1
  • EP4427821B1 patent drawingFigure 2
  • EP4427821B1 patent drawingFigure 3

AI summary

There is disclosed a system for adjusting a stiffness of a running deck for a treadmill having a base, the system comprising: a bracket configured to be coupled to the base of the treadmill; a resilient body adapted to resist movement of the running deck towards the base in a height direction, wherein the resilient body has first and second ends defining a length therebetween, wherein the length is defined in a length direction that is perpendicular to the height direction, and wherein the first end is pivotally coupled to the bracket; a stop wall that is adjustably fixable relative to the base, wherein the length of the resilient body is caused to increase when the running deck moves towards the base until the second end engages with the stop wall; and an adjustment device coupled to the stop wall, wherein the adjustment device is configured to move the stop wall in the length direction to change the length of the resilient body when the second end thereof engages with the stop wall. There is also disclosed a treadmill including the system.