Flexible Spindle Seat Cushion Adjuster for Compact Actuation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional motor-driven seat cushion length adjusting devices are bulky, heavy, complex, and costly, with rigid linear actuators prone to breakage under load, making them unsuitable for compact and adaptable solutions in vehicle seats.

Innovation Solution

A compact seat cushion length adjusting device using a flexible spindle with a wire helix core and speed reduction gearing, allowing a lightweight electric motor, modular design, and easy installation, with a resilient spindle that deforms under axial loads and features a modular design with a worm gear output for efficient torque and speed reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional rigid linear actuators are used for seat cushion length adjustment, then the adjusting device provides sufficient strength and stability, but the device becomes bulky, heavy, and complex

Engineering Contradiction:
ImprovestrengthVSAvoidcomplexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent replaces the conventional rigid linear actuator with a flexible spindle mechanism driven by a rotary motor. The flexible spindle converts rotational motion into linear displacement through its elastic deformation and unwinding, eliminating the need for complex rigid mechanical linkages and reducing overall device complexity while maintaining sufficient strength for seat adjustment applications

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

Solution Approach 2:

The patent employs a flexible spindle made of elastic material that can deform under load and return to its original position. This flexible component replaces traditional rigid mechanical structures, enabling a more compact and simpler adjusting device that still provides the necessary strength and stability for seat cushion length adjustment

Inventive Principle:
Principle #30Flexible shells and thin films

2Strength

If conventional rigid linear actuators are used for seat cushion length adjustment, then the adjusting device provides sufficient strength and stability, but the device increases in size and weight

Engineering Contradiction:
ImprovestrengthVSAvoidweight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent replaces heavy rigid linear actuators with a lightweight flexible spindle mechanism. The elastic spindle and rotary motor combination provides sufficient adjusting force with significantly reduced weight, as the flexible spindle can store and release mechanical energy through elastic deformation rather than requiring heavy mechanical components

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

Solution Approach 2:

The patent changes the physical state and properties of the spindle from rigid to flexible, allowing it to operate in the elastic deformation range. This parameter change enables the use of lighter materials and smaller dimensions while maintaining the strength required for seat adjustment, as the elastic properties allow the component to withstand loads without requiring excessive mass

Inventive Principle:
Principle #35Parameter changes

3Strength

If conventional rigid linear actuators are used for seat cushion length adjustment, then the adjusting device is sturdy, but it becomes prone to breakage under seating loads

Engineering Contradiction:
ImprovestrengthVSAvoidreliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses a flexible spindle made of elastic material that can deform under load and return to its original position. This flexibility allows the spindle to absorb shock and stress from seating loads without permanent deformation or breakage, significantly improving reliability compared to rigid actuators that are more susceptible to catastrophic failure under unexpected loads

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The elastic properties of the flexible spindle provide inherent cushioning against overload conditions. When excessive forces are applied during seating, the spindle deforms elastically to absorb the shock, preventing the transmission of damaging peak loads to other components and reducing the risk of breakage before it occurs

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Extent of automation

If conventional motor-driven adjusting devices are used, then automated control is achieved, but the device becomes complex and costly to install

Engineering Contradiction:
ImproveautomationVSAvoidcomplexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical adjustment mechanisms with a straightforward rotary motor driving a flexible spindle. This substitution maintains automated control capability while dramatically simplifying the mechanical structure, reducing the number of components, and making the device easier and less costly to install in vehicle seats

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

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 provides a compact, lightweight, and cost-effective seat cushion length adjusting mechanism that is durable under loads, easy to install, and adaptable to different customer needs, enhancing user comfort and reducing the risk of breakage.

Implementation Method 1

The spindle may be a flexible spindle which deforms elastically when axial loads less than an axial load of 1200 N are applied

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The spindle may comprise a core and a wire helix wound about the core to form the external thread

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 3

The speed reduction gearing acts as a torque increase gearbox

Methodology Applied
Scientific EffectGear reduction: Gear

Data Source

PatentEP3099524B1Seat cushion length adjusting device and method of adjusting a seat cushion length
Publication Date: 2019.11.06 SCHUKRA GERAETEBAU GMBH
  • EP3099524B1 patent drawingFigure 1~2
  • EP3099524B1 patent drawingFigure 3
  • EP3099524B1 patent drawingFigure 4~5

AI summary

A seat cushion length adjusting device (10) comprises a support (11), an adjusting member (12) displaceably mounted to the support (11) and configured for attachment to at least a portion of a seat cushion, and an actuator. The actuator is coupled to the support (11) and the adjusting member (12). The actuator is configured to displace the adjusting member (12) relative to the support (11). The actuator comprises a power drive (31), a speed reduction gearing, and a motion conversion mechanism (41) for converting a rotational motion of an output of the speed reduction gearing into a linear displacement between the adjusting member (12) and the support (11).