Watch Crown Anti-Rotation Gasket Design
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Solution Overview
Problem
Conventional watch designs with screw locking structures face issues where the screw locking function is impaired due to worn screws, making it difficult to replace the crown and associated parts without compromising watertightness, and existing solutions either require replacing the entire watch enclosure assembly or result in reduced watertightness with frequent crown engagement and disengagement.
Innovation Solution
A watch design featuring a case band with a pipe attachment hole, a winding stem pipe with outer grooves, a ring with inner grooves, and a gasket made of elastic resin that prevents rotation and allows for the removable replacement of the crown and ring while maintaining watertightness, allowing the winding stem pipe to remain fixed to the case band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the winding stem pipe is brazed to the case band to achieve watertightness, then watertightness is improved, but the crown and associated parts cannot be replaced when the screw locking function is impaired
Solution Approach 1:
The invention divides the assembly into separable components: the winding stem pipe remains permanently attached to the case band, while the ring and crown are made replaceable through a modular design. The ring can be removed from the winding stem pipe without removing the pipe itself, enabling crown replacement while maintaining watertightness of the permanent connection.
Solution Approach 2:
The invention introduces a gasket as an intermediary element between the ring and the winding stem pipe. This gasket enables the ring to be removably fitted while maintaining watertightness, serving as a mediator that allows both permanent fixation (for watertightness) and removable engagement (for replaceability).
2Ease of repair
If the winding stem pipe is screwed into the case band to enable replacement, then replaceability is improved, but rotational force during crown engagement and disengagement may loosen the engagement and reduce watertightness
Solution Approach 1:
The invention separates the replacement function from the watertight connection function. The winding stem pipe maintains a permanent watertight connection to the case band, while only the ring and crown components need to be replaceable. This segmentation allows the permanent connection to remain secure while enabling easy replacement of wear-prone parts.
Solution Approach 2:
The invention applies the principle of disposable components by making the ring and crown replaceable parts that can be worn and replaced without affecting the permanent watertight connection. The gasket acts as a sacrificial element that maintains watertightness during repeated engagement cycles while allowing the ring and crown to be replaced when worn.
3Reliability
If adhesive is filled in the engagement portion between winding stem pipe and case band to prevent loosening, then watertightness is improved, but the winding stem pipe cannot be removed for crown replacement
Solution Approach 1:
The invention segments the assembly into a permanent watertight connection (winding stem pipe to case band) and a replaceable connection (ring and crown to pipe). This allows adhesive or other permanent fixation methods to be used at the pipe-case band interface for watertightness, while the ring-crown components remain replaceable through the modular design with gasket-mediated connection.
Solution Approach 2:
The gasket serves as an intermediary that enables the ring to be removably fitted to the winding stem pipe while maintaining watertightness. This intermediary component allows the permanent fixation of the pipe to the case band (potentially with adhesive) while preserving the replaceability of the crown assembly through the removable ring-gasket interface.
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
Enables the replacement of the crown and associated parts without affecting the watertightness, reducing the need for entire assembly replacement and improving operational efficiency by maintaining the initial watertightness and operational feel.
Implementation Method 1
a ring gasket made of elastic resin material that is in close contact with and removably fits on the outer cylindrical surface of the off-case band projection, the gasket restricted in rotation by the outer grooves
Data Source
AI summary
There is provided a watch in which a crown and associated parts, excluding a winding stem pipe, can be replaced when the screw locking function is impaired. The watch includes a case band having a pipe attachment hole, a winding stem pipe, a ring gasket made of elastic resin material, a ring, and a crown. The winding stem pipe is inserted into the pipe attachment hole and fixed to the case band in a liquid tight manner. Outer grooves are formed on the outer cylindrical surface of an off-case band projection of the winding stem pipe that is disposed outside the case band. The removable gasket is fitted on and in close contact with the outer cylindrical surface of the off-case band projection such that the outer grooves prevent the rotation of the gasket. The ring has a male screw formed on the outer cylindrical surface thereof and inner grooves formed on the inner cylindrical surface thereof. The ring is removably fitted on the outer cylindrical surface of the gasket. The gasket is compressed and sandwiched between the ring and the off-case band projection such that the inner grooves prevent the rotation of the gasket. The crown removably engages the male screw of the ring.