Sliding Door Delay Device With Magnetic Lever

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Solution Overview

Problem

Existing sliding door systems for cooling rooms often remain open for too long due to the lack of an automatic closing mechanism, which is complex and costly to implement using electrical drives.

Innovation Solution

A semi-automatic sliding door system that allows manual opening and automatic closing using a reset element with weight or spring force, combined with a delay device featuring a swiveling lever and magnetic holding elements to control the closing time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If an electric drive and control system is used to automatically close the sliding door, then the automatic closing function is achieved, but the device complexity and cost increase

Engineering Contradiction:
Improveautomatic closing functionVSAvoidcomplexity of drive and control system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent replaces the electrical drive and control system with a purely mechanical return element (spring or weight) that automatically pulls the sliding door closed. This mechanical substitution eliminates complex electronics while achieving the same automatic closing function, directly resolving the contradiction between automation and device complexity

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

Solution Approach 2:

The return element is designed to automatically generate the closing force without external control systems. The spring or weight self-regulates the door's movement, requiring no external power source or control logic, thereby achieving automation with minimal complexity

Inventive Principle:
Principle #25Self-service

2Extent of automation

If the sliding door closes immediately using a return element, then automatic closing is achieved, but the delay time for pallet transport is insufficient

Engineering Contradiction:
Improveautomatic closingVSAvoiddoor open duration for transport
Core Design Contradiction:
Extent of automationVSDuration of action of moving object

Solution Approach 1:

The magnetic holding element is pre-positioned to engage with the return element before the door needs to close. This preliminary engagement holds the door open for the required duration, allowing pallet transport to complete before the closing action begins

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The magnetic holding element acts as an intermediary between the return element and the sliding door. It temporarily stores the closing force and releases it at the appropriate moment, enabling both delay and automatic closing functions without requiring complex timing mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

3Duration of action of moving object

If the magnetic holding force is increased to hold the door open longer, then the delay time increases, but the force required to open the door increases

Engineering Contradiction:
Improvedelay timeVSAvoidforce to overcome magnetic holding
Core Design Contradiction:
Duration of action of moving objectVSForce

Solution Approach 1:

The magnetic holding element is designed with dynamic engagement characteristics where the holding force is sufficient to maintain the door in the open position during transport, but the engagement mechanism allows for controlled release when closing is initiated, balancing the force requirements

Inventive Principle:
Principle #15Dynamics

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 efficient automatic closure of sliding doors after a delayed period, reducing energy loss and maintaining a controlled environment without the need for electrical drives, thus being cost-effective and easy to implement.

Implementation Method 1

The first and second magnetic holding elements are designed such that they can releasably magnetically engage one another, i.e., they can come into contact with one another in a magnetically adherent manner. When the first and second holding elements abut one another, a magnetic holding force exists between them

Methodology Applied
Scientific EffectMagnetic holding force: Magnetism

Implementation Method 2

The return element is designed such that it automatically moves the sliding door back into the closed position, for example, by weight or spring force

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

The return element is designed such that it automatically moves the sliding door back into the closed position, for example, by weight or spring force

Methodology Applied
Scientific EffectWeight: Gravitation

Data Source

PatentEP4541993A1Sliding door assembly
Publication Date: 2025.04.23 FRINOVA
  • EP4541993A1 patent drawingFigure 1
  • EP4541993A1 patent drawingFigure 2
  • EP4541993A1 patent drawingFigure 3

AI summary

The invention relates to a sliding door system with a sliding door (2) arranged on a guide rail (6), which can be moved along the guide rail (6) from a closed to an open position, a return element which is connected to the sliding door and is designed such that it moves the sliding door independently into the closed position, and with a delay device (18) which delays the movement caused by the return element (10), wherein the delay device (18) has a pivotable lever (20) which has at least a first magnetic retaining element (24) at its free end, at least a second magnetic retaining element (26) is arranged on the sliding door (2), and the delay device (18) is arranged relative to the sliding door (2) such thatthat in the open position of the sliding door (2) the second magnetic retaining element (26) magnetically engages with the first magnetic retaining element (24), and the delay device (18) is designed such that the lever (20) can be pivoted in a first pivoting direction from a first to a second position and in a second opposite pivoting direction with a delay back to the first position.