No-Frost Cover Mounting with Integrated Undercut Fixation

Solution Overview

Problem

The existing no-frost refrigeration devices require complex and costly fastening parts to secure the cover, which complicates manufacturing and increases costs due to the need for precise assembly to avoid leaks and ensure mechanical strength.

Innovation Solution

The cover is held in place by an undercut formed during deep-drawing of the inner container, with vertical edges engaging in a gap and a contact surface, eliminating the need for separate fastening parts and simplifying the construction process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate fastening parts (screws, claws) are used to secure the cover, then the cover can be held securely on the inner container, but the device complexity and manufacturing cost increase due to multiple parts and precise assembly requirements

Engineering Contradiction:

Improvecover fixation securityVSAvoidnumber of fastening parts

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fastening function is merged into the inner container structure itself through the undercut formation. The undercut is formed as an integrated feature during the deep-drawing process of the inner container, eliminating the need for separate fastening parts. The cover is secured by engaging its vertical edges into this undercut, achieving reliable fixation while simplifying the overall device structure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The undercut structure serves multiple functions: it acts as both a structural feature of the inner container and a fastening mechanism for the cover. This multi-functional design eliminates the need for dedicated fastening components, reducing part count and assembly complexity while maintaining secure cover attachment.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If separate fastening parts are used to secure the cover, then the cover can be held securely, but manufacturing cost increases due to additional parts and assembly labor

Engineering Contradiction:

Improvecover fixation securityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The fastening function is merged into the inner container structure itself through the undercut formation. The undercut is formed as an integrated feature during the deep-drawing process of the inner container, eliminating the need for separate fastening parts. The cover is secured by engaging its vertical edges into this undercut, achieving reliable fixation while simplifying the overall device structure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The inner container structure itself provides the fastening function through the undercut, eliminating the need for external fastening components. The deep-drawing process automatically creates the undercut feature, making the structure self-sufficient for cover attachment without requiring additional parts or assembly steps.

Inventive Principle:

Principle #25Self-service

3Ease of manufacture

If an undercut is formed during deep-drawing of the inner container, then separate fastening parts are eliminated and manufacturing is simplified, but the deep-drawing mold becomes more complex and expensive

Engineering Contradiction:

Improveassembly simplicityVSAvoidmold complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The undercut structure is created in advance during the deep-drawing process of the inner container, before final assembly. This preliminary formation of the fastening feature eliminates the need for separate fastening parts and simplifies subsequent assembly operations, even though it requires a more complex mold.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The fastening function is merged into the inner container structure itself through the undercut formation. The undercut is formed as an integrated feature during the deep-drawing process of the inner container, eliminating the need for separate fastening parts. The cover is secured by engaging its vertical edges into this undercut, achieving reliable fixation while simplifying the overall device structure.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP1926946B1No-frost cooling device

Publication Date: 2018.11.14 BSH HAUSGERATE GMBH

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Figure 3~4

AI summary

The invention relates to a no-frost cooling device which comprises an evaporator chamber (7), an internal container (4) and a covering (20) which separates a bearing chamber (8) from an air channel (19) which communicates with the evaporator chamber (7) in the internal container (4). The covering (20) is maintained on a rear section (27) which is formed on the internal container (4) in a single-piece.