Upright Piano Action Unit Return Accelerator Mechanism
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Solution Overview
Problem
Upright pianos lack the promptness in action units necessary for high-speed repetition, as they do not incorporate repetition levers, leading to missed tones during rapid key movements due to the whippen assemblies' slow return to rest positions.
Innovation Solution
Incorporating a return accelerator mechanism between the whippen assembly and stationary parts of the upright piano, which provides additional force to accelerate the whippen assembly's return to its original position, ensuring timely contact between the jack and hammer assembly, thus enhancing the piano's ability to perform high-speed repetition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the upright piano uses a standard action unit without repetition levers, then the structure is simpler, but the promptness of the action unit deteriorates during high-speed repetition
Solution Approach 1:
A return accelerator lever is introduced as an intermediary component between the whippen assembly and the center rail. This lever acts as a mediator that transfers and amplifies the restoring force during the whippen assembly's return motion, enabling faster response without fundamentally redesigning the entire action unit structure.
Solution Approach 2:
The return accelerator lever is designed to dynamically engage with the whippen assembly during its return motion. The lever's position and engagement timing are optimized to provide acceleration only when needed, allowing the whippen assembly to return faster during repetition while maintaining structural simplicity.
2Device complexity
If the whippen assembly returns slowly to the rest position, then the structure remains simple, but the accuracy of tone production deteriorates during high-speed repetition
Solution Approach 1:
The return accelerator lever serves as a mediator that ensures reliable re-engagement of the jack with the hammer butt during high-speed repetition. By accelerating the whippen assembly's return, the lever guarantees that the jack is in position to transmit force accurately, preventing missed tones while keeping the overall structure relatively simple.
3Speed
If additional force is applied to accelerate the whippen assembly return, then the promptness improves, but the device complexity increases
Solution Approach 1:
The return accelerator lever is designed to be dynamically effective only during the whippen assembly's return motion. The lever's geometry and positioning ensure it provides acceleration during return while remaining unobtrusive during key depression, adding minimal structural complexity while achieving the desired speed improvement.
Solution Approach 2:
The function of the action unit is segmented into key depression (handled by traditional components) and key release (enhanced by the return accelerator lever). This segmentation allows the lever to provide targeted acceleration during return motion without interfering with the traditional key depression mechanism, thereby limiting the increase in overall device complexity.
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 return accelerator mechanism ensures that the jack mechanism can transmit force to the hammer assembly consistently, preventing missed tones during high-speed key repetitions by promptly returning the whippen assembly to its original position, thereby improving the upright piano's promptness and accuracy in tone production.
Implementation Method 1
provides additional force to accelerate the whippen assembly's return to its original position
Implementation Method 2
the jack mechanism can transmit force to the hammer assembly consistently
Implementation Method 3
the hammer assembly escapes from the action units during the rotation of action units, and start free rotation toward the strings
Implementation Method 4
The hammers are brought into collision with the strings at the end of free rotation, and give rise to vibrations of the strings
Data Source
AI summary
An upright piano includes action units between keys and hammers, and the action units are less prompt so that a missing tone tends to take place in a music passage through high-speed repetition; the action unit is constructed from a whippen assembly, a jack mechanism provided on the whippen assembly and a regulating button mechanism for an escape in cooperation with the jack mechanism, and a compression coil spring is provided between a center rail and the whippen assembly for urging the whippen assembly in a direction toward the original position, thereby accelerating the restoration of jack to the contact with the hammer.