Water Resistant Watch Crown Metal Ring Reinforcement
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Solution Overview
Problem
Existing water-resistant watch structures, particularly for saturated diving watches, face challenges in maintaining water resistance under high pressure due to the risk of the packing holding ring coming off, which is made of synthetic resin and fixed by biting.
Innovation Solution
A watch design featuring a crown with a metal ring positioned between the shaft portion and the stem pipe, using a packing with a larger second distance to ensure compression and secure water resistance, and a metal ring with higher mechanical strength to prevent the packing from coming off, even at deep-sea pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a packing holding ring made of synthetic resin is used to hold the packing, then the device complexity is reduced and ease of manufacture is improved, but the reliability of water resistance deteriorates under high pressure
Solution Approach 1:
The patent uses a composite structure combining synthetic resin (for the packing holding ring) and metal (for the reinforcing ring). The metal reinforcing ring is embedded in the synthetic resin packing holding ring to provide high strength under water pressure while maintaining the ease of manufacture benefits of the synthetic resin structure.
2Device complexity
If the packing holding ring is fixed by bitting in the stem pipe, then the device complexity is reduced, but the reliability of water resistance deteriorates due to risk of coming off under high pressure
Solution Approach 1:
The patent creates a composite packing holding ring structure where a metal reinforcing ring is embedded within the synthetic resin packing holding ring. This composite structure provides both the simplicity of the bitting fixation method and the reliability needed to withstand high water pressure without the ring coming off.
Solution Approach 2:
The metal reinforcing ring has a curved shape that conforms to the cylindrical stem pipe, allowing it to be effectively fixed by bitting while distributing stress evenly under water pressure. The curved geometry enables the thin metal ring to provide maximum structural support within the constrained space.
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 solution provides reliable water-resistant performance for diving watches by preventing the packing from dislodging under high pressure and allowing for a compact, miniaturized design without compromising water resistance.
Implementation Method 1
a packing disposed between the surface of the shaft portion and the first surface
Implementation Method 2
a packing disposed between the surface of the shaft portion and the first surface
Data Source
AI summary
A watch includes: a crown including a head portion and a shaft portion; a stem pipe including a first surface that includes an insertion hole through which the shaft portion is inserted and has a distance from a surface of the shaft portion as a first distance in cross-sectional view, and a second surface that is provided at a position closer to an end portion of the insertion hole than the first surface and has a distance from the surface of the shaft portion as a second distance larger than the first distance; a packing disposed between the surface of the shaft portion and the first surface; and a metal ring that is disposed between the surface of the shaft portion and the second surface and is in contact with the packing.