Torque-Switched Clutch for Double-Leaf Door Locking

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Solution Overview

Problem

Existing double-leaf door closing sequence control systems face challenges in handling the specific order of closing leaves when the active leaf overlaps the passive leaf, particularly in ensuring the passive leaf reaches the closed position before the active leaf, and suffer from complex and unreliable rotational adjustments of detection levers due to screw connections, which are prone to loosening and lack robustness against vandalism.

Innovation Solution

A torque-switched clutch is introduced between the selector shaft and detection lever, allowing defined rotational adjustments without damaging the components, and a slipping clutch design with a plate spring clutch spring provides a simple, compact solution that absorbs switching forces and allows non-destructive rotational adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a screw connection is used to adjust the rotational position of the detection lever, then the adjustment can be made, but the connection is prone to loosening and lacks robustness against vandalism

Engineering Contradiction:
Improverotational adjustment of detection leverVSAvoidrobustness against loosening and vandalism
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The harmful screw connection is extracted and replaced with a torque-switched clutch mechanism. The detection lever is no longer adjustably mounted via screw but is instead positively engaged through clutch teeth that transmit torque only in the switching direction, eliminating the loosening problem while maintaining adjustability during installation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The torque-switched clutch acts as an intermediary between the detection lever and the selector shaft. It provides a controlled torque transmission path that allows intentional adjustment during installation but prevents unauthorized rotational adjustment during operation, thereby protecting against vandalism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the detection lever is rotated relative to the selector shaft during operation, then the switching function can be adjusted, but the screw connection may loosen and cause malfunction

Engineering Contradiction:
Improveadjustment of switching functionVSAvoidstability of connection during operation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The clutch connection transitions from a static screw-fixed state during installation to a dynamic torque-controlled state during operation. The one-way clutch mechanism allows rotational adjustment only during the installation phase when controlled torque is applied, but locks the position during operation to prevent loosening while maintaining the ability to adjust the switching function.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotational adjustment of the detection lever is performed as a preliminary action during installation before the system enters operational mode. Once installed, the torque-switched clutch prevents further unauthorized adjustments, ensuring that the switching function is set correctly during installation without risking loosening during subsequent operations.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the locking device remains in the locking state, then the active leaf is secured against premature closing, but the closing sequence cannot be executed

Engineering Contradiction:
Improveprevention of premature closingVSAvoidexecution of closing sequence
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system uses feedback from the detection lever's position to automatically control the locking device's state. When the passive leaf reaches its closed position, the detection lever's rotational position triggers the torque-switched clutch to release the locking device, allowing the active leaf to close. This feedback mechanism ensures the locking device switches states at the correct moment, maintaining security while enabling the closing sequence.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The closing sequence control system is self-regulating through the interplay between the detection lever, torque-switched clutch, and locking device. The system automatically transitions from the locking state to the release state based on the passive leaf's position, without requiring external intervention, thereby ensuring both security and operational continuity.

Inventive Principle:
Principle #25Self-service

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 ensures reliable switching of the locking device from a locked to a release state without undesired displacement of the detection lever, enhancing the robustness and ease of operation while resisting vandalism, and limits the rotation angle to prevent damage to the switching elements.

Implementation Method 1

a slipping clutch design with a plate spring clutch spring provides a simple, compact solution that absorbs switching forces and allows non-destructive rotational adjustments

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2924218B1Device for regulating the closing sequence of a stationary wing and a moveable wing of a two-wing door and two-wing door fitted with such a device
Publication Date: 2017.05.03 GRETSCH UNITAS GMBH BAUBESCHLAGFABRIK
  • EP2924218B1 patent drawingFigure 1~2
  • EP2924218B1 patent drawingFigure 3~4
  • EP2924218B1 patent drawingFigure 5

AI summary

A device (12) for controlling the closing sequence of a fixed leaf and an active leaf of a double-leaf door comprises an active leaf closing device, a fixed leaf closing device, and a switchable locking device. The locking device secures the open active leaf in a locking state against movement in the closing direction by means of the active leaf closing device and, in a release state, releases it for movement in the closing direction by means of the active leaf closing device. A switching device (14) is provided for switching the locking device. The switching device has a detection lever (17) and a switching shaft (18). The switching shaft (18) extends perpendicular to the detection lever (17) and is rotatable about a shaft axis (21) extending parallel to the main plane of the fixed leaf. Together with the detection lever (17), the switching shaft (18) performs a switching rotary movement over a release rotation angle.As a result, the locking device for the door leaf is moved from the locked state to the released state. The connection between the shift shaft (18) and the detection lever (17) allows the detection lever (17) to be rotated relative to the shift shaft (18) about the shaft axis (21). For this purpose, a torque-switching clutch (20) is provided between the shift shaft (18) and the detection lever (17). A double-leaf door is equipped with a device of this type.