Removable Cab Toe Box for Sealed Access and Cab Rotation

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Solution Overview

Problem

Conventional cab designs for compact loaders, such as skid steer loaders and compact track loaders, face challenges in providing adequate service access and sealing performance due to their geometry, which limits interior dimensions and obstructs maintenance access.

Innovation Solution

A removable toe box system is integrated into the cab, allowing for additional foot space and improved sealing, while enabling the cab to rotate without interference from lift arm cylinders by being detachable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional sealed rotatable cab is used, then operator protection and sealing are improved, but service access to equipment underneath the cab is blocked

Engineering Contradiction:
Improvesealing performanceVSAvoidservice access
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cab is divided into two separate parts: a stationary floor assembly and a rotatable upper cab assembly. This segmentation allows the upper cab to rotate for service access while the floor remains in place, resolving the contradiction between maintaining sealing and enabling access to equipment underneath.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The toe box is extracted as a separate removable component from the cab floor. This allows the toe box to be removed when service access is needed, while the rest of the sealed cab structure remains intact, maintaining both protection and accessibility.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If a two-part cab design is used to improve foot space by rotating the upper cab, then service access is improved, but sealing performance is reduced

Engineering Contradiction:
Improveservice accessVSAvoidsealing performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The cab is segmented into a stationary floor assembly with sealing surfaces and a rotatable upper cab assembly. The segmentation includes integrated sealing components that maintain the seal between parts when closed, while allowing rotation when opened for service access.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the cab is tilted from the front to improve service access, then access geometry is improved, but interior dimensions are reduced and lift arms must be raised first

Engineering Contradiction:
Improveservice accessVSAvoidinterior dimensions
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

Instead of tilting the cab forward to access equipment, the invention allows the cab to rotate backward or sideways about a vertical axis. This inverted approach to access geometry maintains interior dimensions while providing service access without requiring lift arm movement.

Inventive Principle:
Principle #13The other way round (Inversion)

4Ease of operation

If a fixed toe box is installed to provide additional foot space, then operator comfort is improved, but cab rotation is interfered with by lift arm cylinders

Engineering Contradiction:
Improveoperator comfortVSAvoidcab rotation
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The toe box is designed as a dynamic, removable component rather than a fixed structure. It can be installed when operator comfort is needed and removed when cab rotation is required, adapting to different operational requirements and resolving the contradiction between comfort and versatility.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4151802B1Removable cab toe box for a work machine
Publication Date: 2026.01.28 CATERPILLAR SARL
  • EP4151802B1 patent drawingFigure 1
  • EP4151802B1 patent drawingFigure 2
  • EP4151802B1 patent drawingFigure 3

AI summary

Removable cab (112) toe boxes (240) are described herein to provide increased comfort to an operator while still allowing a cab (112) to be rotated upwards to provide access to equipment below the cab (112). The removable toe boxes (240) are removably affixed to the cab (112) and, when installed, may provide at least a partial seal to prevent or reduce the amount of dirt or dust entering the cab (112). When the toe boxes (240) are removed, equipment may move through the space created from the removal of the toe boxes (240) to allow the cab (112) to rotate.