Furniture Motion Accelerator With Intermediate Spring Locking

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Solution Overview

Problem

Existing acceleration devices for movable furniture parts, such as drawers and doors, face issues with abrupt loss of actuation force and potential injury due to uncontrolled energy release when springs are tensioned, especially in limited spaces, and require manual intervention for unlocking.

Innovation Solution

An acceleration device with a deflection mechanism that couples an energy storage device to a driver, allowing it to be fixed at an intermediate position between minimally and maximally tensioned states, preventing complete energy discharge and enabling smooth operation without manual lock release, using a disk-shaped base body with a changing torque application and a control cam for locking positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If short, strong springs with high spring rate are used to achieve sufficient closing force in limited installation space, then the closing force is adequate, but the abrupt loss of actuation force after spring tensioning causes negative user perception

Engineering Contradiction:
Improveclosing forceVSAvoiduser perception of actuation force
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent applies a progressive spring rate that changes during the closing movement. The spring rate is low in the initial phase to provide gentle user feedback, then increases in the intermediate phase to build closing force, and maintains high value in the final phase to ensure complete closure. This parameter change resolves the contradiction by providing both adequate closing force and smooth user perception throughout the operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The spring characteristics are made dynamic rather than static. The spring rate transitions from low to high during the closing movement, adapting to different phases of the operation. This dynamic approach allows the system to provide gentle initial resistance to the user while building up to the necessary closing force, eliminating the abrupt force loss perceived by users.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If spring tensioning is interrupted during operation, then the energy absorbed by the spring is released against the direction of movement, but this causes furniture parts to return to starting position and potentially injure the operator

Engineering Contradiction:
Improveoperation flexibilityVSAvoidinjury risk from uncontrolled movement
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a locking mechanism as an intermediary between the spring and the furniture part. This locking mechanism can hold the spring in a tensioned intermediate position, preventing uncontrolled energy release. When the spring is interrupted during tensioning, the locking mechanism engages to secure the position, eliminating the harmful rebound effect while maintaining operation flexibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The locking mechanism provides beforehand protection against uncontrolled spring release. By preparing the locking capability in advance, the system can safely interrupt the tensioning process at any point without risking injury from sudden energy release. The locking mechanism acts as a safety buffer that prevents harmful effects before they can occur.

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

3Object-affected harmful factors

If manual locking mechanisms are added to prevent uncontrolled spring release, then safety is improved, but the device complexity increases and manual intervention is required

Engineering Contradiction:
Improveinjury riskVSAvoidlocking mechanism complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The locking mechanism is designed to operate automatically without manual intervention. The locking element engages and disengages automatically based on the position and movement of the furniture part, eliminating the need for user action. This self-service approach maintains safety while avoiding the complexity and usability issues associated with manual locking systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The locking function is merged with the existing spring mechanism and guide structure. Rather than adding a separate, complex locking system, the patent integrates the locking capability into the existing components, reducing overall device complexity while maintaining the safety function. The locking element works in conjunction with the spring and guide track to provide automatic protection.

Inventive Principle:
Principle #5Merging (Combining)

4Productivity

If the spring is allowed to fully tension and discharge in limited installation space, then the closing action is effective, but the abrupt force change creates a tearing sensation for the user

Engineering Contradiction:
Improveclosing efficiencyVSAvoiduser comfort during operation
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The spring rate parameter is changed progressively throughout the closing movement rather than remaining constant. The progressive spring rate profile (low-initial, increasing-intermediate, high-final) ensures that the force builds smoothly and maintains effectiveness throughout the operation. This resolves the contradiction by providing both efficient closing action and comfortable user experience without abrupt force changes.

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

The solution effectively prevents abrupt force loss and injury by managing energy storage and release, allowing for easy operation and complete closure/opening of furniture parts without manual lock release, enhancing user safety and convenience.

Implementation Method 1

a spring tensioning system (100) with which a movable furniture part (20) can be accelerated in the opening direction

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

The deflection device has a sequence curve which changes the distance between the articulation point of the energy accumulator and an axis of rotation of the deflection device during a tensioning or relaxation process

Methodology Applied
Scientific EffectTorque: Torque

Data Source

PatentEP2948023B1Accelerating device for moveable furniture or domestic-appliance parts
Publication Date: 2018.03.14 PAUL HETTICH GMBH & CO KG
  • EP2948023B1 patent drawingFigure 1
  • EP2948023B1 patent drawingFigure 2
  • EP2948023B1 patent drawingFigure 3

AI summary

An accelerating device for moveable furniture parts, in particular drawers or doors, has a housing (2), an energy store (4), which has a first end fastened on the housing (2), at least one driver (13), which is arranged in a displaceable manner on the housing (2) and can be prestressed by the energy store (4), and a deflecting device (10), which is mounted on the housing (2) and via which the energy store (4) is connected to the driver (13), wherein the deflecting device (10) is coupled to a mechanical blocking device, by means of which the energy store (4), during the course of a stressing operation, can be secured in at least one intermediate position between a minimally stressed position and a maximally stressed position.