Key Drive Device for Acoustic Piano Without Leg Block Cutting

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Solution Overview

Problem

The installation of a key drive device on an acoustic piano is complicated by the need to cut leg blocks, which prolongs the installation process and alters the piano's appearance, as the device protrudes downward and interferes with leg blocks below the key bed.

Innovation Solution

A key drive device design that allows installation without removing leg blocks by accommodating solenoids and a circuit board in a manner that avoids interference with leg blocks, using a configuration where solenoid accommodating portions are positioned higher than the key bed's lower surface and circuit-board accommodating portions are positioned lower, allowing the device to be fixed without cutting the leg blocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If the key drive device is installed in the key bed space, then the keys can be driven automatically, but the device protrudes downward and interferes with leg blocks, requiring cutting of the leg blocks

Engineering Contradiction:
Improveautomatic playing functionVSAvoidinstallation complexity
Core Design Contradiction:
Extent of automationVSEase of manufacture

Solution Approach 1:

The key drive device is divided into multiple drive units, each independently accommodating solenoids and circuit boards. This segmentation allows each unit to be optimized for its specific spatial requirements and enables flexible arrangement to avoid interference with leg blocks while maintaining the automatic playing function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent repositions the circuit-board accommodating portions to extend downward from the key bed's lower surface, utilizing the vertical dimension to route circuit boards away from the leg block interference zone. This dimensional rearrangement allows the solenoid accommodating portions to remain in the key bed space for automatic key driving while the circuit boards are routed through a different spatial path.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the key drive device protrudes downward from the key bed, then the solenoids can be accommodated, but the leg blocks must be cut to avoid interference

Engineering Contradiction:
Improvesolenoid accommodation spaceVSAvoidinstallation time
Core Design Contradiction:
Volume of moving objectVSLoss of time

Solution Approach 1:

The key bed is designed with pre-formed receiving spaces for the solenoid accommodating portions at appropriate heights, and the circuit-board accommodating portions are pre-configured to extend downward in a controlled manner. This preliminary structural preparation eliminates the need for cutting leg blocks during installation, allowing the device to be installed as a complete unit without time-consuming modifications to the piano structure.

Inventive Principle:
Principle #10Preliminary action

3Shape

If the key drive device is installed without cutting leg blocks, then the piano's appearance is preserved, but the device must be designed to avoid interference with leg blocks

Engineering Contradiction:
Improvepiano appearanceVSAvoiddevice structure
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

Different portions of the key drive device are designed with different spatial characteristics: the solenoid accommodating portions are positioned at specific heights within the key bed, while the circuit-board accommodating portions extend downward in controlled regions. This local differentiation allows the device to navigate around the leg blocks without interference, preserving the piano's appearance while accommodating all necessary components.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The circuit-board accommodating portions are nested within or adjacent to the solenoid accommodating portions, with the circuit boards routed through spaces created by the solenoid unit structures. This nesting arrangement allows both components to coexist in a compact configuration that avoids the leg block interference zone, maintaining the piano's external appearance.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Enables efficient installation of the key drive device on acoustic pianos without cutting leg blocks, reducing installation time and preserving the piano's appearance by avoiding interference with leg blocks, and allowing for easy maintenance and reattachment.

Implementation Method 1

a solenoid (101) for driving an associated key (20)

Methodology Applied
Scientific EffectSolenoid: Solenoid

Data Source

PatentEP2477185B1Key drive device and keyboard musical instrument
Publication Date: 2015.07.15 YAMAHA CORP
  • EP2477185B1 patent drawingFigure 1
  • EP2477185B1 patent drawingFigure 2
  • EP2477185B1 patent drawingFigure 3

AI summary

A key drive device (10; 10A; 10B) to be installed on a musical instrument (1) with a keyboard (2) partly located above a leg block (4) via a key bed (3). In a state in which the drive units (10-L, 10-U; 10A-L, 10A-U; 10B-L, 10B-U) are installed, at least one drive unit which drives at least one key located above the leg block includes: (a) a first portion (100b; 100Ab; 100Bb) at least a part of which is inserted into an insertion space portion (30b) of the removal space between the leg block and the keyboard; and (b) a second portion (100a, 200a; 100Aa, 200Aa; 100Ba, 200Ba) at least a part of which is disposed in other space portion(30a) of the removal space, a dimension of the second portion in at least one of a vertical direction and a horizontal short-side direction being larger than that of the first portion.