Industrial Truck Mortise Switch Lock Anti-Tamper Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Mortise switch locks for industrial trucks often inadvertently activate the second switching stage during normal operation, which can lead to unintended engagement of emergency functions like the parking brake, posing safety risks and operational inefficiencies.

Innovation Solution

A mortise switch lock design featuring a blocking section on the key handle that can be displaced between blocking and release positions, with a spring-biased blocking projection preventing accidental rotation into the second switching stage, ensuring deliberate actuation is required to access the emergency rescue function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a second switching stage is added to the mortise switch lock for emergency rescue functions, then the vehicle can be released from emergency shutdown or parking brake activation, but the risk of unintentional activation during normal operation increases

Engineering Contradiction:
Improveemergency rescue functionVSAvoidunintentional activation
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The blocking section is positioned in advance to prevent entry into the second switching stage during normal key rotation. The user must first deliberately move the blocking section to the release position before the key can be turned to access the emergency rescue function, ensuring preliminary intentional action is taken

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the key can be freely rotated through all switching stages, then operation is simple and quick, but accidental engagement of the parking brake may occur during normal driving

Engineering Contradiction:
Improvekey rotationVSAvoidswitching stage activation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The key rotation path is segmented into distinct phases: normal operation range (first switching stage) and emergency rescue range (second switching stage). The blocking section acts as a mechanical gate that must be deliberately moved to permit transition to the second stage, separating routine operations from emergency functions

Inventive Principle:
Principle #1Segmentation

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

Prevents unintentional activation of the second switching stage, enhancing operational safety by ensuring deliberate user intervention, thereby maintaining normal vehicle operation without unexpected engagement of emergency functions.

Implementation Method 1

the blocking section is biased into the blocking position by a spring

Methodology Applied
Scientific EffectSpring action: Spring

Data Source

PatentEP2143600B1Plug-in switch lock for an industrial truck
Publication Date: 2011.03.02 JUNGHEINRICH AG
  • EP2143600B1 patent drawingFigure 1~6

AI summary

The lock (10) has a locking projection (20) at a side turning towards a handle of a plug-in key (12). The handle includes a locking section e.g. disk, which is displaceably supported between a locking position and a release position. An actuating section actuates the locking section. The locking projection blocks twisting of the plug-in key in a switching stage when the locking section is in a locking position. The locking projection releases blocking of the key in the switching stage when the locking section is in the release position.