Sheet Metal Armrest Assembly for Lower Weight and Fastener Count
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing armrests in aircraft and vehicles are heavy and complex, requiring multiple fasteners and machined metal parts, which increases weight and cost.
Innovation Solution
An armrest design comprising a lightweight structural frame made of sheet metal, clad with a thermoplastic shell, and cushion parts, assembled with a minimal number of fasteners, allowing for quick and easy assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If heavy metal materials are milled and machined to create the armrest structure, then strength and durability are improved, but weight and manufacturing complexity increase
Solution Approach 1:
The patent changes the manufacturing parameters from traditional milling and machining of solid metal to bending and folding of sheet metal. This parameter change maintains structural strength while dramatically reducing weight and manufacturing complexity. The sheet metal frame is formed by bending operations rather than removing material, achieving both strength and weight reduction.
Solution Approach 2:
The armrest employs a composite construction combining sheet metal frame, plastic shell, and cushioning materials. This composite approach allows each material to contribute its optimal properties: the sheet metal provides structural strength, the plastic shell provides durability and aesthetics, and the cushioning provides comfort, while keeping overall weight lower than solid metal construction.
2Reliability
If multiple fasteners and additional structures are used to assemble the armrest, then structural integrity and functionality are improved, but component number, assembly complexity, and cost increase
Solution Approach 1:
The patent merges multiple functions into integrated components. The sheet metal frame is formed with built-in attachment features that combine structural support and fastening functions. The plastic shell is designed with integrated mounting structures that eliminate separate fasteners. This merging reduces component count and assembly complexity while maintaining structural integrity.
Solution Approach 2:
The armrest is segmented into modular components (sheet metal frame, plastic shell, cushioning) that can be manufactured separately and assembled simply. Each segment is designed with standardized attachment interfaces that simplify assembly. The segmentation allows for easier manufacturing and assembly while maintaining overall structural integrity through standardized connection methods.
3Manufacturing precision
If traditional machining processes are used for armrest production, then manufacturing precision is improved, but production time and cost increase
Solution Approach 1:
The sheet metal frame is pre-formed with bending and folding operations that create the final shape and attachment features in fewer steps. The pre-forming process establishes precise geometric relationships between frame members before final assembly, ensuring dimensional accuracy while reducing subsequent machining requirements and production time.
Data Source
AI summary
An armrest comprising: an internal structural frame formed of sheet metal parts (10, 20) bent or folded to define an outer shape of the frame and that define spaces therebetween; a shell (70, 80) provided over the structural frame and comprising a first shell half (70) fitted over a first side of the structural frame and a second shell half (80) fitted over an opposite side of the structural frame, the first and second shell halves overlapping at an inner portion (72) where they meet; a cushion part (90, 100) comprising a cushion mounting frame (220) and a cushion (200) mounted thereon, the cushion frame mounted to the shell; and two or more fasteners (301, 302, 303) each of which extends through the structural frame, the shell and the cushion mounting frame.