Autoharp Keyboard Mechanism With Adjustable String Damping
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Solution Overview
Problem
Existing autoharp mechanisms that damp strings from beneath are complex, difficult to manufacture, require periodic adjustments, and result in a bulky instrument with potential string rattling, lacking a simple and reliable solution for compact and even damping.
Innovation Solution
A design featuring octave bars with piano-like keys, damping brackets located under the strings, and adjustable length spacers to ensure consistent damping force, eliminating the need for complex linkages and allowing for a compact autoharp.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dampers are located under the strings with complex linkage systems to raise dampers off strings when pressing keys, then string damping control is achieved, but device complexity increases and manufacturing difficulty increases
Solution Approach 1:
Instead of raising dampers off strings when keys are pressed (conventional approach), this invention inverts the approach by having dampers rest on strings and lowering them when keys are pressed. The octave bars with piano keys directly push the dampers down onto the strings, eliminating the need for complex linkage systems that convert downward key pressure into upward damper motion.
Solution Approach 2:
The invention extracts and eliminates the complex linkage system from the mechanism. By using octave bars that slidingly engage with pins and directly transmit downward key pressure to the dampers, the intermediary linkage components are removed, simplifying the overall device structure while maintaining reliable damping control.
2Reliability
If multiple brackets are used for each string tuned to a note to ensure adequate damping, then damping effectiveness is improved, but manufacturing precision requirements increase and adjustment difficulty increases
Solution Approach 1:
The invention merges multiple separate brackets into a single integrated damper assembly. Each octave bar supports multiple dampers for different strings as a unified structure, eliminating the need to manufacture and adjust multiple individual brackets. This consolidation maintains damping effectiveness for all strings tuned to a note while significantly reducing manufacturing precision requirements and adjustment complexity.
3Adaptability or versatility
If brackets are made flexible and under tension to adapt to different string diameters, then adaptability to different strings is improved, but device complexity increases and periodic adjustments are required
Solution Approach 1:
The invention uses adjustable length spacers that can be set to different lengths to accommodate different string diameters and positions. Instead of making brackets flexible and tense, rigid spacers are adjusted to the appropriate length for each string configuration, providing adaptability while maintaining structural simplicity and eliminating the need for periodic adjustments.
4Object-affected harmful factors
If damping brackets are positioned close to the treble-string side to prevent string rattling, then string rattling is reduced, but instrument width increases and compactness is reduced
Solution Approach 1:
The invention resolves the spatial conflict by positioning the adjustable spacers in the longitudinal dimension (along the string length) rather than requiring extension in the lateral dimension (instrument width). The spacers can be adjusted along the length of the octave bar to optimize damper positioning for preventing string rattling without increasing the overall width of the instrument, maintaining compactness.
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 design simplifies manufacturing, reduces mechanical noise, ensures even damping without periodic adjustments, and maintains a compact instrument size, enabling comfortable upright play and easy retrofitting to conventional autoharps.
Implementation Method 1
Coil springs are arranged around each of pins and are located beneath the octave bars and the damping brackets
Implementation Method 2
The portion of the bracket below the string holds the damping material, so that springs that push the bar upwards hold the damping material against the string
Data Source
AI summary
The Autoharp Keyboard Mechanism is engaged with an autoharp having strings. Octave bars having piano-like keys are slidingly engaged with pins extending from the top surface of the autoharp and are located above the strings. Damping brackets are also slidingly engaged with the pins and are located beneath the octave bars and beneath the strings. Coil springs are arranged around each of pins and are located beneath the octave bars and the damping brackets. Adjustable length spacers are engaged with the octave bars and with the damping brackets, one at each end of the octave bars and damping brackets. The adjustable length spacers are located between the octave bars and the damping brackets, and are engaged with the octave bars using threads. Holders are configured to retain the octave bars on the pins.