Acoustic Radiation Arrangement for Musical Watch Case Back
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Solution Overview
Problem
Existing musical or striking watches face challenges in optimizing acoustic radiation, particularly from the bottom of the watch case, which remains acoustically inactive due to vibration damping when worn on the wrist, and struggle to maintain watertightness and resistance to external pressures while enhancing sound quality across a wide frequency band.
Innovation Solution
An acoustic radiation arrangement is introduced, featuring a support and connection piece fixed between the bottom bezel and back glass, with a flexible intermediate part that allows vibro-acoustic coupling, optimizing sound emission from the bottom cavity and ensuring watertightness and mechanical resistance, even when worn.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the bottom of the watch case is made rigid to ensure watertightness and mechanical resistance, then structural integrity is improved, but acoustic radiation efficiency deteriorates
Solution Approach 1:
The bottom of the watch case is segmented into two distinct parts: a rigid peripheral portion that ensures watertightness and mechanical resistance, and a flexible central membrane portion that enables acoustic radiation. This segmentation allows each part to fulfill its specific function without compromising the other.
Solution Approach 2:
Different regions of the bottom are assigned different mechanical properties: the peripheral region is made rigid for structural integrity and sealing, while the central region is made flexible for acoustic radiation. This local differentiation of material properties resolves the contradiction between strength and acoustic performance.
2Reliability
If side openings are provided in the bottom to enable sound radiation, then acoustic efficiency is improved, but dirt penetration and lack of tightness worsen
Solution Approach 1:
The bottom membrane is designed to be dynamically responsive to acoustic vibrations while maintaining static sealing. During sound radiation, the membrane flexes to allow sound passage; during non-use, it returns to its sealed position, preventing dirt penetration and maintaining watertightness without requiring permanent openings.
3Reliability
If membranes are added to improve acoustic radiation, then sound quality is improved, but device complexity increases
Solution Approach 1:
The flexible membrane in the bottom serves multiple functions simultaneously: it acts as a sound radiation diaphragm, maintains watertightness when sealed, provides mechanical support for the movement, and allows visibility of the movement through its transparent or translucent material. This multi-functionality improves acoustic performance without proportionally increasing complexity.
4Illumination intensity
If the bottom is made transparent to view the movement, then aesthetic visibility is improved, but dirt entry risk increases
Solution Approach 1:
The bottom membrane is made from transparent or translucent flexible material that allows viewing of the movement while maintaining sealing capability. The flexible nature enables it to conform and seal around openings, preventing dirt entry while the transparency preserves aesthetic visibility of the movement through the bottom.
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 arrangement enhances acoustic efficiency across a wide frequency band, increases sound duration, reduces noise through anti-resonance, and maintains watertightness and resistance to high pressures, while preventing dirt entry and ensuring the mechanical movement remains visible.
Implementation Method 1
a flexible intermediate part (5c) which connects the two rigid parts (5a, 5b) and allows vibro-acoustic coupling
Implementation Method 2
the vibrations of the gong or of the blades of the keyboard are transmitted to the various covering parts... These covering parts are for example the middle part, the bezel, the crystal and the back of the watch case. These large trim pieces begin to radiate sound into the air as a result of the transmitted vibrations
Implementation Method 3
The frequencies of the generated notes must be close to the proper modes of vibration of the membranes so that they enter into resonance
Data Source
Figure 1~3
Figure 2
Figure 4
AI summary
The musical or striking watch (1) is equipped with an acoustic radiating mechanism. The watch includes a watch case (2, 7) consisting of at least a case middle (7) and a case back (2) removably attached to the case middle, and at least one crystal (16) for closing the case. The acoustic radiating mechanism includes a support and connection piece (5) fixed in the case back between a case back bezel (12) and a case back crystal (6). The case back bezel (12) includes several lateral openings (3). A cavity (4) is defined between the support and connection piece (5) and the openings (3) of the case back bezel.