Keyboard Pivot Member Mass Adjustment via Hole Patterns
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Solution Overview
Problem
Existing keyboard apparatuses face challenges in manufacturing weights for each key due to small differences in mass between hammers for close pitches, leading to increased complexity and reduced productivity, as well as difficulties in freely designing dynamic and static loads.
Innovation Solution
A keyboard apparatus design featuring pivot members with a support member and a structure having a specific gravity greater than the support member, where the mass and shape of hole portions in the pivot members differ, allowing for adjustable mass and center of gravity, enabling flexible design of dynamic and static loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If weights are manufactured one by one for each key to achieve precise mass differences, then the touch feeling accuracy is improved, but the manufacturing productivity deteriorates
Solution Approach 1:
A single mold is designed to produce multiple types of weights (first, second, and third types) with different masses by forming different hole patterns. This universal mold can manufacture all weight types used in the keyboard apparatus, eliminating the need for separate molds for each weight and significantly improving manufacturing productivity while maintaining precise mass control through varied hole configurations
Solution Approach 2:
Different hole patterns (first, second, and third hole portions) are strategically positioned within the weight structure to create specific mass distributions. By varying the location, size, and configuration of these holes, precise mass differences are achieved for different keys while using the same base weight design, enabling customized touch feelings without requiring completely different weight designs for each key
2Manufacturing precision
If the mass of weights is decreased stepwise from low-pitched to high-pitched keys to reproduce acoustic piano touch, then the touch feeling accuracy is improved, but the manufacturing complexity increases
Solution Approach 1:
The mass of weights is systematically varied by changing the hole pattern parameters (size, position, shape) rather than redesigning the entire weight structure for each key. This parameter-based approach allows stepwise mass reduction from low-pitched to high-pitched keys while maintaining a unified weight design framework, reducing manufacturing complexity compared to completely custom designs for each key
Solution Approach 2:
The weight structure is divided into a base form and variable hole portions. The hole portions are segmented into different types (first, second, third hole portions) that can be independently configured to achieve the desired mass characteristics. This segmentation allows systematic mass variation while maintaining design consistency across all keys
3Device complexity
If a single rod-like mass is used as weight to simplify the structure, then the device complexity is reduced, but the flexibility to adjust mass and center of gravity is limited
Solution Approach 1:
While maintaining the simple rod-like overall structure, local quality is introduced through different hole patterns (first, second, and third hole portions) positioned at specific locations along the rod. These localized modifications enable flexible adjustment of mass and center of gravity without complicating the overall rod-like structure, achieving both structural simplicity and design flexibility
Solution Approach 2:
Asymmetric hole patterns are introduced into the symmetric rod-like structure to create varied mass distributions. The hole portions are positioned and sized asymmetrically to achieve specific center of gravity locations and mass characteristics required for different keys, while the basic rod-like form remains simple and easy to manufacture
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
This design allows for the independent adjustment of static and dynamic loads across keys, improving manufacturing efficiency and productivity by simplifying the weight design and distribution, while maintaining accurate touch and sound reproduction.
Implementation Method 1
the hammer of the electronic keyboard instrument pivots with respect to a frame so as to raise a weight provided for the hammer
Data Source
AI summary
A keyboard apparatus includes: a frame; keys each disposed pivotably with respect to the frame; pivot members each including: a support member disposed pivotably about a pivot shaft; and a structure connected to the support member at a position spaced apart from the pivot shaft, the structure having a specific gravity that is greater than that of the support member. A hole portion is formed in each of a first structure and a second structure, each of which is the structure of a corresponding one of a first pivot member and a second pivot member of at least two of the pivot members, such that a mass of the first structure and a mass of the second structure are different from each other. The hole portion of the first structure and the hole portion of the second structure are different from each other in shape.