Keyboard Key Shaft Clearance for Spacing Adjustment
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Solution Overview
Problem
Existing keyboard instruments face challenges in adjusting key spacings due to restricted movement of keys when shaft holes and shaft sections are of similar sizes, leading to unequal spaces between keys.
Innovation Solution
The keyboard instrument design incorporates shaft holes and shaft sections with specific dimensions, where first spaces are smaller in the vertical direction and second spaces are larger in the longitudinal direction, allowing for key rotation and adjustment of spacings between keys by displacing the attachment pieces within these defined spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If shaft holes and shaft sections are made of similar sizes to restrict key movement, then key stability is improved, but key spacing adjustment capability deteriorates
Solution Approach 1:
The shaft hole is designed with non-uniform clearance distribution: small clearance in the vertical direction (first space) for stability, and large clearance in the longitudinal direction (second space) for adjustment capability. This local differentiation of clearance quality resolves the contradiction between stability and adjustability.
Solution Approach 2:
The clearance between shaft and shaft hole is made asymmetric: the first space in the vertical direction is smaller than the second space in the longitudinal direction. This asymmetric clearance design allows the key to be stable vertically while permitting longitudinal movement for spacing adjustment.
2Manufacturing precision
If shaft sections are tightly fitted into shaft holes to prevent movement, then manufacturing precision is improved, but ease of operation deteriorates
Solution Approach 1:
The fit between shaft and shaft hole is locally differentiated: tight fit in the vertical direction for precision, and loose fit in the longitudinal direction for ease of adjustment. This local quality variation resolves the contradiction between manufacturing precision and operational ease.
Solution Approach 2:
The clearance design transforms the static tight fit into a dynamic system where the key can move freely in the longitudinal direction for adjustment while maintaining vertical stability. The different clearance sizes in different directions enable this dynamic behavior.
3Device complexity
If keys are rotatably attached with circular shafts and holes of the same size, then structural simplicity is improved, but key spacing uniformity deteriorates
Solution Approach 1:
While maintaining the simple circular cross-section of shaft and shaft hole, the invention introduces local quality differentiation through non-uniform clearance distribution. The first space (vertical) is smaller than the second space (longitudinal), enabling uniform key spacing through controlled movement without increasing structural complexity.
Solution Approach 2:
The invention changes the clearance parameter distribution rather than the basic circular geometry. By making the first space smaller than the second space, the system achieves uniform key spacing while maintaining the simplicity of circular shaft and shaft hole structures.
Data Source
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AI summary
A keyboard instrument Including a plurality of keys (2) and a keyboard chassis (1), in which each key (2) has a shaft (21) or a shaft hole (20) provided on one end side thereof. The keyboard chassis (1) is provided with shafts (21) when the plurality of keys (2) has shaft holes (20), and is provided with shaft holes (20) when the plurality of keys (2) has shafts (21). This keyboard chassis (1) supports the plurality of keys (2) by the shafts (21) being arranged in the shaft holes (20) . Also, first spaces (S1) and second spaces (S2) are formed between an inner surface of the shaft hole (20) and the shaft (21). The first spaces (S1) are positioned in a vertical direction of the key (2), and the second spaces (S2) are positioned in a longitudinal direction of the key (2). In addition, the second spaces (S2) are larger than the first spaces (S1).