Adjustable Screw-Down Crown for Angular Indexing

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Solution Overview

Problem

Existing screw-down crown assembly methods for watches are inadequate for crowns with patterns or non-revolutionary designs, failing to allow angular indexing adjustments after screwing, which compromises aesthetics, especially in luxury products.

Innovation Solution

An orientable screw-down crown with a subassembly featuring a crown body and a tube, incorporating a frontal indexing relief and a complementary relief on a fixed barrel, utilizing a helical spring to enable axial movement and relative rotation for angular orientation adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a screw-down crown is assembled using conventional methods, then the crown can be screwed into the housing and sealed, but the crown cannot be adjusted to a specific orientation relative to the case after screwing

Engineering Contradiction:
Improveorientation precisionVSAvoidassembly mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The crown assembly is divided into separate functional components: a crown body with indexing relief, a fixed barrel with complementary relief, and a movable barrel. This segmentation allows the orientation adjustment mechanism to be integrated without complicating the overall assembly process, as each component has a specific function and can be manufactured independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The movable barrel acts as an intermediary element between the crown body and the fixed barrel. It enables the relative rotation and axial movement necessary for orientation adjustment while maintaining the sealed connection. The movable barrel with its indexing relief cooperates with the complementary relief on the fixed barrel to provide precise angular positioning.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If a screw-down crown with pattern or relief is assembled, then the crown can be sealed and fixed, but the aesthetic orientation relative to the case cannot be controlled

Engineering Contradiction:
Improvecrown orientationVSAvoidassembly simplicity
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The indexing reliefs are pre-configured on the crown body and fixed barrel during manufacturing. This preliminary arrangement of the indexing features allows the crown to be oriented correctly relative to the case without requiring complex adjustment procedures during assembly or wear.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The crown assembly mechanism allows the user to perform orientation adjustment independently by manipulating the movable barrel and crown body. The indexing reliefs engage automatically to provide the correct orientation, eliminating the need for specialized assembly tools or procedures.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the crown is designed with indexing relief and movable barrel, then angular orientation adjustment is enabled, but the structural complexity increases

Engineering Contradiction:
Improveangular indexing capabilityVSAvoidsubassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The indexing mechanism, movable barrel, and sealing function are merged into a single integrated subassembly. The movable barrel with its indexing relief works in conjunction with the complementary relief on the fixed barrel to provide both orientation adjustment and sealed connection, eliminating the need for separate components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The movable barrel serves multiple functions: it provides the interface for angular indexing adjustment, maintains the sealed connection between the crown body and fixed barrel, and enables axial movement for orientation changes. This multi-functionality reduces the overall complexity by eliminating the need for separate components for each function.

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

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 reliable and economical orientation of the screw-down crown relative to the watch case, maintaining watertight sealing while allowing angular indexing, thus enhancing the aesthetic and functional reliability of luxury watches.

Implementation Method 1

a movable barrel (7), which is captively mounted in a chamber (31) formed by the juxtaposition, on the one hand, of the crown body (1) or respectively of the ring (2) and on the other hand of the fixed barrel (3), and in which chamber (31) the movable barrel (7) is captively mounted by the fixed barrel (3); Each crown spring (4) is placed between the fixed barrel (3) and the first axial stop means (8)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3805871B1Adjustable threaded crown
Publication Date: 2024.01.17 MECO SA
  • EP3805871B1 patent drawingFigure 1~2
  • EP3805871B1 patent drawingFigure 3~4
  • EP3805871B1 patent drawingFigure 5~11

AI summary

A rotating screw-down crown (10) for a watch case (100), a subassembly (20) of which comprises a tube (9) axially insertable into a case housing (90), and an operating body (1) having a motif (19) and a frontal relief (15) extending radially and, in the engaged position, cooperating for indexing the motif (19) relative to the case (100) with a complementary frontal relief (35) comprising a fixed barrel (3) which is drawn back towards the body (1) by a spring (4) held between them, and remaining axially distant from the complementary relief (35) and without cooperating with it in the disengaged position by compression of the spring (4), the subassembly (20) having an axial stop (8) fixed to the body (1) to axially hold the fixed barrel (3) with a stroke corresponding to the deformation of the spring (4) to allow disengagement, by pulling the body (1), between the relief (15) and the complementary relief (35).