Constant Force Spring Guide Frame for Adjustable Furniture

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Solution Overview

Problem

Conventional adjustable workstation furniture has limited vertical motion speed and range, leading to increased strain and time requirements for users, particularly in packaging work, and relies on external power sources, which are costly and inefficient.

Innovation Solution

A mechanical arrangement using a guide frame with constant force springs to enhance the vertical motion range and speed of work surfaces, allowing for manual adjustment with reduced user effort and eliminating the need for external power sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional adjustable furniture is used, then the furniture can be adjusted in height, but the vertical motion speed is limited and adjustment takes too much time

Engineering Contradiction:
Improvevertical motion speedVSAvoidadjustment time
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The patent transforms the static adjustment mechanism into a dynamic one by introducing a constant force spring that enables continuous motion throughout the adjustment range. The spring provides ongoing force to move the work surface vertically at high speed, eliminating the need for slow incremental adjustments and enabling motion speeds of 10-40 mm per second over ranges of 300-600 mm.

Inventive Principle:
Principle #15Dynamics

2Length of moving object

If conventional adjustable furniture with limited motion range is used, then the furniture structure remains compact, but the motion range is insufficient for packaging work with materials of varying heights

Engineering Contradiction:
Improvevertical motion rangeVSAvoidfurniture structure complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The patent segments the adjustment system into independent modular components: the constant force spring mechanism, the guide frame, and the work surface assembly. This segmentation allows each component to be optimized independently, achieving a large vertical motion range of 300-600 mm while keeping the overall structure manageable and the components easily replaceable.

Inventive Principle:
Principle #1Segmentation

3Speed

If electric or pneumatic adjustable parts are used, then the motion speed and range are improved, but the cost increases significantly with external power sources accounting for 40-70% of total furniture cost

Engineering Contradiction:
Improveadjustment speedVSAvoidmanufacturing cost
Core Design Contradiction:
SpeedVSEase of manufacture

Solution Approach 1:

The constant force spring mechanism is self-powered, utilizing mechanical energy stored in the spring to drive the adjustment without requiring external electricity or pneumatic systems. This self-service approach eliminates costly power sources, control electronics, and associated infrastructure, reducing manufacturing costs while maintaining high adjustment speeds and large motion ranges.

Inventive Principle:
Principle #25Self-service

4Ease of operation

If conventional adjustment mechanisms are used, then the furniture can be adjusted, but user strain increases particularly on shoulder joints during manual adjustment

Engineering Contradiction:
Improveuser effortVSAvoiduser strain on shoulder joints
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The constant force spring acts as a counterweight mechanism that balances the weight of the work surface and packaging materials throughout the adjustment range. By providing continuous upward force that offsets gravity, the spring reduces the effort users must exert, particularly during lifting and positioning operations, thereby minimizing strain on shoulder joints and improving ergonomics.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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 significant increase in motion range and speed, reducing user strain and operational time by up to 90%, while being cost-effective and ergonomic, and enabling the use of heavier work surfaces without straining the user's shoulder joints.

Implementation Method 1

a transfer means (21) consisting of a constant force spring to transfer the unit of furniture (19) in the vertical direction

Methodology Applied
Scientific EffectConstant force spring: Spring

Implementation Method 2

The opening of the motion prevention affecting the unit of furniture and the adjusting of its use height are quickly performable by the employee manually because the force effect provided by the transfer means is weighted with the combined mass of the unit of furniture and the sliding parts being in co-operation with it

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Implementation Method 3

a guide frame (11) the height of which is at least the targeted motion range and to which other parts of the furniture are attached

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP4052611B1Arrangement for adapting adjustable furniture to adjustment profiles
Publication Date: 2024.08.07 TRESTON OY
  • EP4052611B1 patent drawingFigure 1~4
  • EP4052611B1 patent drawingFigure 5~6
  • EP4052611B1 patent drawingFigure 7~9

AI summary

The present invention relates to an adjustment profile (11) comprising an elongated means, substantially square of its cross section which means is provided with evenly spaced fastening openings (13) on at least one of its surfaces for receiving fastening means. In the cross section of this adjustment profile, one of its four sides is open for the whole length dimension of the adjustment profile comprising two opposite edge profiles (12) shaped substantially symmetrical to form a linear guide. Between the two opposite edge profiles (12) forming this linear guide is here arranged a moving carriage (16), whereby the motion of the carriage is supported by at least two bearing units (18) supported on opposite edge profiles.