Waterproof Casing with Pinch Strip Snap-Fit Assembly

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Solution Overview

Problem

Conventional waterproof structures for mobile phones require large casing sizes due to screw fasteners, leading to uneven deformation of waterproof rubber and inconsistent fastening forces, resulting in reduced waterproofing effectiveness and increased assembly time.

Innovation Solution

A waterproof structure using a first casing, a second casing, and a waterproof pad, with guide grooves and pinch strips that engage to create a uniform pressure fit, eliminating the need for screws and reducing casing size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If screw fasteners are used to assemble the first casing and the second casing, then the waterproof effect is achieved through extrusion deformation, but the casing size must be large to accommodate the screws and the fastening force is uneven

Engineering Contradiction:

Improvewaterproof effectVSAvoidcasing size

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent removes the screw fasteners from the assembly system and replaces them with a snap-fit structure. The first and second casings are equipped with guide grooves and corresponding guide protrusions that enable direct engagement without external fastening elements, thereby reducing casing size while maintaining assembly reliability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent integrates the fastening function into the casing structure itself by designing guide grooves and guide protrusions that are part of the casing bodies. This merging of the fastening mechanism with the casing structure eliminates the need for separate screw fasteners and reduces overall assembly complexity

Inventive Principle:

Principle #5Merging (Combining)

2Manufacturing precision

If multiple screws are arranged to ensure even fastening force, then the waterproof soft rubber deformation is controlled, but the assembly time and manufacturing complexity increase significantly

Engineering Contradiction:

Improveeven deformation of waterproof soft rubberVSAvoidassembly time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent divides the fastening function into multiple guide grooves and guide protrusions distributed along the engagement length. This segmentation allows the fastening force to be distributed evenly across multiple contact points, ensuring uniform deformation of the waterproof soft rubber while simplifying the assembly process compared to using multiple screws

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The guide grooves and guide protrusions are designed to automatically align and engage the first and second casings during assembly. This self-aligning mechanism eliminates the need for precise manual positioning and multiple screw tightening operations, significantly reducing assembly time while maintaining even fastening force distribution

Inventive Principle:

Principle #25Self-service

3Reliability

If screw fasteners are used to secure the casings, then the waterproof effect is initially achieved, but the waterproof effect is lost when screws become loose or lost over time

Engineering Contradiction:

Improvewaterproof effectVSAvoiddurability of waterproof effect

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

Instead of using threaded fasteners that can loosen over time, the patent inverts the fastening mechanism to use a snap-fit design where the guide protrusions engage with the guide grooves in a non-reversible manner. This inversion creates a more reliable connection that maintains constant fastening force and prevents the waterproof effect from degrading over time

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent incorporates the waterproof soft rubber as a cushioning element between the first and second casings. This rubber component compensates for any minor dimensional variations and maintains consistent contact pressure, ensuring the waterproof effect remains reliable even after prolonged use and mechanical shocks

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

The solution provides a reliable and consistent waterproof effect with reduced assembly time and improved efficiency, as the pinch strips ensure even deformation of the waterproof pad across the engagement length, maintaining waterproof integrity over time.

Implementation Method 1

the waterproof soft rubber generates an extrusion deformation interference when pressed, the waterproof effect between the first casing and the second casing is accordingly achieved

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS10320438B2Waterproof structure and mobile phone using the same

Publication Date: 2019.06.11 POWER IDEA TECH (SHENZHEN) CO LTD

AI summary

A waterproofing structure including a first casing, a waterproof pad, a second casing, and two pinch strips. Two first guide grooves and two second guide grooves are defined at either side of both casings. Each pinch strip is fitted and fastened to one first guide groove and one second guide groove to assemble and hold together the first and second casings, and so compressing the waterproofing pad between the two casings. Uniform pressure is applied to the waterproof pad at all points. The entire engagement section does not need screws, thus saving screwing time, and improving assembly efficiency. A mobile phone is also disclosed, the mobile phone has a complete sealing and waterproofing, and an assembly efficiency is improved.