Seamless Metal Personal Care Housing With Covered Shell Openings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing personal care devices with metal shells face challenges in manufacturing complex shapes with precise edges, achieving a tight fit with functional components while maintaining ergonomic and aesthetic design, and avoiding skin irritation from sharp edges.
Innovation Solution
A method of forming a seamless, one-piece metal shell using hydraulic pressure forming, incorporating undercuts and plastic chassis members to cover edges, ensuring a tight fit and ergonomic handling while reducing skin irritation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If openings and perforations are created in the metal shell for inserting functional components, then accessibility and mounting are enabled, but sharp and burred edges are created that can irritate skin
Solution Approach 1:
A plastic chassis member is introduced as an intermediary element that is inserted into the opening of the metal shell. This chassis member has a surface that extends beyond the outer surface of the metal shell, thereby covering the sharp edge of the opening. The chassis member acts as a mediator between the user's skin and the sharp metal edge, eliminating skin irritation while maintaining accessibility to functional components.
2Shape
If the outer metal shell is formed with complex three-dimensional shapes and undercuts, then ergonomic handling and aesthetic appearance are improved, but manufacturing precision and ease of manufacture deteriorate
Solution Approach 1:
The device is segmented into two main parts: the metal shell and the plastic chassis member. The metal shell is formed with simplified geometry that is easier to manufacture with high precision, while the complex three-dimensional shape and undercuts are realized through the separately manufactured plastic chassis member. This segmentation allows each component to be optimized for its specific manufacturing process, with the chassis member compensating for the simplified metal shell geometry.
3Strength
If the metal shell is made tight-fitting to accommodate functional components, then device compactness and strength are improved, but ease of assembly and disassembly deteriorates
Solution Approach 1:
The device is divided into separable components: the metal shell, the plastic chassis member, and functional components. The chassis member serves as an intermediate assembly element that can be inserted into the metal shell through its opening. This segmentation allows functional components to be mounted on the chassis member first, and then the entire assembly can be easily inserted into or removed from the metal shell, maintaining both structural strength and ease of assembly.
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 allows for the creation of personal care devices with complex shapes and precise edges, providing a tight fit with functional components, maintaining strength and aesthetics, and reducing skin irritation from sharp edges.
Implementation Method 1
a forming step includes a hydraulic pressure-forming step for deforming a metal shell blank into a desired shape
Data Source
AI summary
The present invention relates to a personal care device such as an electric hair cutter like shaver or toothbrush, and to a method of manufacturing such personal care device. More particularly, the personal care device comprises a handle and a function head supporting at least one personal care tool, said function head being attached to said handle, wherein at least one of said handle and said function head includes an outer metal shell formed in one piece with an integral, homogeneous, seamless structure having a ring-like or sleeve-like shape with closed annular cross-sections. Said outer metal shell includes at least one undercut portion which is formed with a hydraulic pressure forming step.