Cab Front Window Lock Device with Swingable Lock Body

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Solution Overview

Problem

Conventional locking devices for construction machine front windows require a large number of parts and complex adjustments, with degraded operability due to the need for multiple components and connections, especially when releasing the locking mechanism at closed and opened positions.

Innovation Solution

A locking device with a mechanism that includes a lock body with an engagement groove, a holding member, and a release operation lever, allowing the lock body to swing into locking postures for both closed and opened positions, reducing the number of parts and enabling direct operation for releasing the lock, thus simplifying the mechanism and improving operability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pair of right and left window-closing-side and window-opening-side hooks and engagement pins are used, then the front window can be locked at both closed and opened positions, but the number of parts increases and the device complexity increases

Engineering Contradiction:
Improvelocking reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the closing-side lock and opening-side lock into a single integrated locking device. The lock body includes a single engagement groove that can engage with either the closing-side engagement pin or the opening-side engagement pin, eliminating the need for separate locking mechanisms for each position. This merging reduces the number of parts while maintaining the ability to lock the window at both closed and opened positions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking device is designed with multi-functionality to perform both closing-side locking and opening-side locking operations. The lock body can swing between different angular positions to engage with different engagement pins, and the single engagement groove serves multiple locking functions. This universal design allows one device to replace what would traditionally require multiple separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If a connection member (lock release bar) is used to connect the right and left locking devices, then the locking can be released, but the number of parts increases and the device complexity increases

Engineering Contradiction:
Improverelease operationVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The release lever is integrated directly into the locking device structure, eliminating the need for a separate connection member (lock release bar) to connect right and left locking devices. The release lever is positioned to directly act on the lock body, allowing simultaneous release of both closing-side and opening-side locking through a single operation point. This integration reduces the number of parts while maintaining ease of operation.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If release lever operation through multiple parts is required, then the locking can be released, but the operability of the release lever is degraded

Engineering Contradiction:
Improverelease operationVSAvoidoperability
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The release lever is extracted from a complex multi-part connection system and repositioned to directly act on the lock body. By removing the intermediate connection members and simplifying the transmission path, the release lever's operation is directly transmitted to the locking mechanism without degradation. This extraction and repositioning improves operability by reducing the number of parts through which the release force must pass.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If right and left engagement positional adjustment is required simultaneously, then proper locking can be achieved, but the adjustment work becomes difficult and time-consuming

Engineering Contradiction:
Improveengagement reliabilityVSAvoidadjustment work
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The engagement groove and engagement pins are designed as a unified system where the relative positions are predetermined by the single locking device structure. The engagement groove's position and orientation are fixed relative to the lock body, and the engagement pins are positioned to match this fixed geometry. This unified design eliminates the need for complex simultaneous adjustments of multiple independent engagement points, significantly simplifying the assembly and adjustment process while ensuring reliable engagement.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2149640B1Lock device for front window of cab
Publication Date: 2012.06.27 SHIN CATERPILLAR MITSUBISHI LTD CORP
  • EP2149640B1 patent drawingFigure 1
  • EP2149640B1 patent drawingFigure 2
  • EP2149640B1 patent drawingFigure 3

AI summary

Provided is a lock device for locking a front window capable of freely opening an closing at the closed position and the opened position in which the number of parts is reduced and the operational feeling during its releasing operation is improved. The lock device comprises a lock mechanism part installed on the front window side and lock reception bodies of the closed side and the opened side respectively installed on the cab side. The lock mechanism part includes a lock body the attitude of which can be changed among the neutral attitude, the closed side lock attitude and the opened side lock attitude, a holding member for holding the closed side lock attitude and the opened side lock attitude of the lock body, and an operation lever for release acting on the holding member to release the holding of the lock body by the holding member.