Resin Keyboard Frame Reducing Weight via Segmented Support

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Solution Overview

Problem

Conventional keyboard apparatuses with resin frames supporting keys and hammers inefficiently use resin, leading to increased weight and cost due to wastage and lack of design freedom, as they require broad contact areas to withstand loads.

Innovation Solution

A keyboard apparatus with a resin frame that applies heavy loads perpendicularly to front-side and rear-side contact portions, reducing the frame's area and resin usage by positioning key guides and initial stoppers strategically, eliminating unnecessary thickened portions and ribs, and supporting the frame only at these contact areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the frame is configured to be in contact at a broad longitudinal area with the musical instrument main body, then the frame can withstand the loads applied by keys and hammers, but a large amount of resin is used resulting in wastage and increased weight

Engineering Contradiction:
Improveload withstanding capabilityVSAvoidframe weight
Core Design Contradiction:
StrengthVSWeight of stationary object

Solution Approach 1:

The contact area between the frame and musical instrument main body is segmented into discrete contact portions rather than a continuous broad area. This segmentation allows the frame to withstand loads through concentrated support points while reducing the total amount of resin material needed, thereby decreasing frame weight without compromising structural strength.

Inventive Principle:
Principle #1Segmentation

2Strength

If ribs or other thickened portions are formed at or between the key supports, the hammer supports, and the contact portions of the frame, then the frame can withstand the applied loads, but the amount of resin is increased and cost rises

Engineering Contradiction:
Improveload bearing capacityVSAvoidresin quantity
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

Instead of forming ribs or thickened portions throughout the frame structure, the invention applies local quality by concentrating reinforcement only at the specific contact portions where loads are transmitted to the musical instrument main body. This localized reinforcement strategy provides necessary strength at critical points while minimizing overall resin consumption and reducing manufacturing costs.

Inventive Principle:
Principle #3Local quality

3Shape

If the frame is designed with thickened portions at locations forward and downward of the hammer supports, then the frame appears thick from front view, but there is scope for reduction of resin amount and improvement of design freedom

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidresin amount
Core Design Contradiction:
ShapeVSQuantity of substance

Solution Approach 1:

The invention extracts the aesthetic function of thickened portions from the structural design. Instead of relying on substantial thickened portions to achieve the desired thick appearance from the front view, the design separates visual appeal from structural reinforcement, allowing for reduced resin usage while maintaining the aesthetic quality through alternative design approaches.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2169662B1Keyboard instrument
Publication Date: 2012.11.21 YAMAHA CORP
  • EP2169662B1 patent drawingFigure 1
  • EP2169662B1 patent drawingFigure 2
  • EP2169662B1 patent drawingFigure 3A~3B

AI summary

A keyboard apparatus configured that heavy loads to support keys and hammers are perpendicularly applied to front-side and rear-side contact portions and the area of a front part of a frame as seen from side can be reduced, thereby suppressing an amount of use of resin. The keyboard apparatus includes a frame integrally formed by resin and mounted with a stopper mounting portion to which an initial stopper is mounted. The frame is supported on a keybed only by front-side and rear-side supporting portions respectively contacting the keybed at locations beneath hammer pivot shafts and beneath key supports. In a longitudinal region between the stopper mounting portion and the front-side supporting portion, the height position of a lowermost part of the frame become higher at a position closer to the stopper mounting portion.