Watch Crown Tube With Direction Memory

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Solution Overview

Problem

Existing watch case crown designs fail to reliably maintain the angular orientation of a distinctive sign with respect to the watch case's longitudinal axis, often resulting in a random position due to the limited number of indexing positions and requiring complex setups with multiple tubes, which can also lead to separation issues under torque.

Innovation Solution

A watch case design featuring a control crown with a first tube having axial toothing and a middle part with a through hole, where the first tube is axially blocked by a shoulder and a second tube, ensuring the distinctive sign's correct orientation by using a special tool for screwing, and maintaining orientation after unscrewing and rescrewing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple tubes are used to fix angular orientation, then the distinctive sign's orientation is maintained, but the device complexity increases

Engineering Contradiction:
Improveangular orientation of distinctive signVSAvoidnumber of tubes and components
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple separate tubes into a single integrated tube structure. The first tube combines the functions of the previous separate tubes while maintaining the indexing mechanism with its toothing that engages with the middle part, thereby reducing component count while preserving angular orientation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single tube is designed to perform multiple functions simultaneously: it provides structural support, enables angular positioning through its toothing that engages with the middle part, and maintains the distinctive sign's orientation. This multi-functional design eliminates the need for multiple specialized components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If indexing means are provided on multiple tubes, then angular orientation is fixed, but the ease of manufacture decreases

Engineering Contradiction:
Improveangular orientation fixationVSAvoidassembly setup difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The indexing means are consolidated into a single toothing structure on the first tube that engages with the middle part, rather than distributing indexing mechanisms across multiple tubes. This simplification makes the assembly process more straightforward and easier to manufacture.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If a clamping ring is used to hold the outer part, then the crown is secured, but the device complexity increases

Engineering Contradiction:
Improvecrown securingVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The clamping function is integrated into the single tube structure itself, which is screwed onto the middle part. The tube's threaded engagement with the middle part provides the clamping action needed to secure the crown, eliminating the need for a separate clamping ring component.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If three separate tubes are used, then angular orientation can be adjusted, but the ease of operation decreases

Engineering Contradiction:
Improveangular orientation adjustmentVSAvoidassembly and disassembly
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The adjustable angular orientation feature is maintained through the engagement between the single tube's toothing and the middle part's toothing. This single integrated mechanism is easier to operate than coordinating three separate tubes, while still providing the necessary angular positioning capability.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2592500B1Watch case comprising a crown wheel with direction memory
Publication Date: 2019.01.16 ROLEX SA
  • EP2592500B1 patent drawingFigure 1~2
  • EP2592500B1 patent drawingFigure 3~4
  • EP2592500B1 patent drawingFigure 5~6

AI summary

The case has a tube provided with indexing elements (1a), and a control crown (C) including a cap (4) having a distinctive sign (S) such as brand or logo, on a front face (4') of the case. Another tube is fastened to middle (3) of the case to receive a bush (5). The control crown and the former tube include respective screwing elements for screwing the crown and the tube together. The tubes are conformed, so that fastening of the latter tube to the middle of the case ensures axial immobilization of the former tube relative to the middle of the case. An independent claim is also included for a method for assembling a watch case.