Electrical Box Hinge Geometry for Tool-Free Door Removal

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Solution Overview

Problem

Existing electrical box hinges are impractical for easy dismantling during maintenance, as they require time-consuming screw removal and can be complex and expensive to produce, with existing solutions being either cumbersome or requiring specialized tools.

Innovation Solution

An electrical box design featuring a hinge with a knuckle and pin where the pin is released from a groove, allowing the door to be easily separated, and a manufacturing method where the knuckle is integral with the box, molded, and includes a groove formed within, enabling tool-free assembly and disassembly with a specific angle between the groove plane and the box opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional hinges with screws are used to connect the door to the box, then the connection is strong and reliable, but the disassembly process becomes time-consuming and complex

Engineering Contradiction:
Improveconnection reliabilityVSAvoiddisassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The hinge is divided into two separate parts: a knuckle fixed to the box and a pin mounted on the door. This segmentation allows the door to be easily detached by simply removing the pin, eliminating the need to unscrew multiple fasteners while maintaining a secure connection when assembled

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pin is extracted as a separate removable component from the traditional screw-based hinge mechanism. By taking out the fastening element (pin) as a distinct part that can be independently removed, the design enables quick door detachment without affecting the structural integrity of the box or door when closed

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If removable hinge designs are implemented to allow easy door detachment, then the ease of operation improves, but the device complexity and production cost increase

Engineering Contradiction:
Improvedoor detachment easeVSAvoidhinge complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Instead of making the knuckle removable (as in conventional designs), the invention inverts the approach by making the pin removable while the knuckle remains fixed to the box. This inversion simplifies the overall hinge structure, as the knuckle can be integrally molded with the box, reducing part count and manufacturing complexity

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

Solution Approach 2:

The knuckle is merged with the box as a single integral component through molding, eliminating the need for separate hinge mounting operations. This merging reduces the number of parts and assembly steps while maintaining the functionality of the hinge mechanism

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If the knuckle width is made substantially equal to the pin diameter, then the manufacturing precision is improved, but the ease of manufacture decreases

Engineering Contradiction:
Improveknuckle-pin fit precisionVSAvoidmolding ease
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The design specifies that the knuckle width be substantially equal to the pin diameter, creating a precise fit that ensures proper alignment and secure connection. This parameter relationship, while requiring precise molding, is achieved through standard injection molding techniques and provides reliable hinge functionality

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4074932B1Electrical box and method for manufacturing such an electrical box
Publication Date: 2023.12.27 SCHNEIDER ELECTRIC IND SAS
  • EP4074932B1 patent drawingFigure 1
  • EP4074932B1 patent drawingFigure 2
  • EP4074932B1 patent drawingFigure 3

AI summary

An electrical enclosure (1) comprises a housing (3) defining an opening (37), a door (5) configured to close the opening of the housing when in the closed position, and at least one hinge, the hinge connecting the door to the housing by pivoting. The hinge comprises a pin (9) and a spindle (8). The pin of the hinge includes a groove (97) for receiving the spindle, which extends in a groove plane (P97) along the entire length of the pin, and the width (L97) of the pin's groove is substantially equal to a diameter (D81) of the hinge spindle. To facilitate the mounting and dismounting of the door, the spindle is mounted on the door, the pin is fixed to the housing, or integral with the housing, and an angle (β) between the groove plane and a plane (P37) of the opening is between 5° and 35°.