Safety Door Interlock Latch With Detent Piston Locking

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Solution Overview

Problem

Existing locking devices for protective doors require a ratchet wheel, increasing space requirements and necessitating precise key alignment, which limits their compact design and reliability in ensuring secure locking.

Innovation Solution

A locking device with a detent piston and a locking trough, utilizing a spring-driven locking piston and a bistable lifting magnet for mechanical latching, combined with an RFID tag for non-contact identification, allowing flexible angle insertion and enhanced locking security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking wheel is used in the locking mechanism, then the locking function can be achieved, but the space requirements increase and the design becomes less compact

Engineering Contradiction:
Improvelocking functionVSAvoidspace requirements
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The invention extracts the locking wheel from the locking mechanism and replaces it with a plunger that directly engages with detent elements on the actuator. This removal of the locking wheel eliminates the need for a separate housing component, thereby reducing space requirements while maintaining the locking function through direct plunger-actuator engagement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the functions of the locking wheel and plunger into a single integrated locking mechanism. The plunger, now without a locking wheel, directly interacts with detent elements that are integrated onto the actuator itself, combining multiple components into a more compact unified structure.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a locking wheel is used in the locking mechanism, then the locking action can be achieved, but precise key insertion and alignment are required

Engineering Contradiction:
Improvelocking actionVSAvoidkey insertion precision
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention removes the locking wheel that required precise alignment with the key. Instead, the plunger directly engages with detent elements on the actuator, eliminating the alignment requirement between key and locking mechanism while maintaining reliable locking action through the plunger's direct interaction with the actuator's detent elements.

Inventive Principle:
Principle #2Taking out (Extraction)

3Force

If the locking piston is spring-driven, then high locking forces can be achieved, but the mechanism becomes more complex

Engineering Contradiction:
Improvelocking forcesVSAvoidmechanism complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The invention combines the spring-driven plunger with integrated detent elements on the actuator into a unified locking mechanism. This merging reduces overall complexity by eliminating separate locking wheels and housings, while the spring continues to provide high locking forces through direct plunger engagement with the actuator's detent elements.

Inventive Principle:
Principle #5Merging (Combining)

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 high locking forces, reduces space requirements, ensures precise locking, and allows for flexible installation while ensuring secure operation through mechanical and electronic monitoring.

Implementation Method 1

The locking piston is therefore a latching piston. Furthermore, the mechanical latching function allows for locking. By locking the locking piston, the latching unit and actuator are mechanically connected. The latching action is achieved by a spring-driven locking piston

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

In addition to the locking recess, the actuator contains an electronic identification element, specifically an RFID tag. An RFID sensor located in the locking unit allows for the reliable detection of the RFID tag's position

Methodology Applied
Scientific EffectRFID: Electromagnetic Induction

Implementation Method 3

The locking shaft/pin can be moved by a bistable solenoid

Methodology Applied
Scientific EffectSolenoid: Solenoid

Data Source

PatentEP3657063B1Locking device with closing system for safety belts
Publication Date: 2023.09.06 K A SCHMERSAL HLDG
  • EP3657063B1 patent drawingFigure 1
  • EP3657063B1 patent drawingFigure 2
  • EP3657063B1 patent drawingFigure 3

AI summary

Locking device with interlock for safety doors, comprising a mechanical actuator (1) attachable to a movable door part and a housing (2) that interacts with the actuator (1) and is attachable to a door counterpart, the housing (2) having a receptacle (3) into which the actuator (1) can be inserted, and the housing (2) having a locking element (4) that is displaceable between an unlocked position, in which the actuator (1) can be released, and a locked position, in which the actuator (1) can be fixed relative to the receptacle (3), wherein the actuator (1) has an engagement tongue (5) with an engagement recess (6) for mechanical engagement with a head-end (7) of a locking element (4) designed as a detent piston (8), which is guided longitudinally displaceably in the housing (2) in a piston longitudinal direction relative to an internal, bushing-shaped fixed bearing under spring bias. (9) which carries radially movable and fixable locking elements (10),which lock the locking piston (8) on its inner contour (21) in the locked position during a defined state, for which purpose the locking piston (8) has a longitudinally effective locking stop (11) on the inner contour (21).