Timepiece Crown with Segmented Blades for Polygonal Stone Fixation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for fixing precious or semi-precious stones on timepiece control members, such as winding crowns, are limited to circular cabochons and require significant crimping or are unsuitable for non-circular shapes, affecting aesthetics and functionality.

Innovation Solution

A control member with a flat front face featuring parallel blades that crimp a cabochon-shaped stone with a polygonal base, allowing for secure fixation without visible crimping, using notches on the stone's end faces to deform the blades and secure the stone in place.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a traditional rim folding method is used to fix a stone, then the stone can be securely fixed, but the method is only suitable for circular cabochons and requires the stone diameter to be smaller than the control element diameter

Engineering Contradiction:
Improvestone shape compatibilityVSAvoidsetting method applicability
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The control element's front face is segmented into multiple straight sides (at least three) instead of a continuous circular rim, allowing each side to independently engage with corresponding sides of polygonal cabochons. This segmentation enables versatile stone shape compatibility while maintaining secure fixation through the blade structure that can be deformed into notches for each stone side.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If elastic arms with grooves are used to engage the stone (as in US 2013/0291587), then the stone can be fixed, but the stone must be cut to standard diamond size and shape, resulting in significant setting thickness

Engineering Contradiction:
Improvestone shape flexibilityVSAvoidsetting thickness
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The blade structure provides localized engagement points at the notches formed on the control element's front face, rather than requiring uniform engagement across the entire stone perimeter. This local quality approach allows thin cabochons with polygonal bases to be securely fixed at specific points (notches) without requiring the stone to be cut to standard diamond dimensions, thereby reducing setting thickness while maintaining adaptability to various stone shapes.

Inventive Principle:
Principle #3Local quality

3Productivity

If retaining elements with a band are used (as in US 2002/0166338), then multiple stones can be held in place, but the design is not suitable for fixing a single stone and adds complexity

Engineering Contradiction:
Improvemulti-stone capabilityVSAvoidsetting structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention extracts the essential fixation function from the complex multi-stone band system and applies it to a simplified single-stone configuration. By using a blade structure that can be deformed into notches, the patent achieves secure single-stone fixation without requiring the full complexity of retaining elements and connecting bands, thereby reducing device complexity while maintaining effective stone holding capability.

Inventive Principle:
Principle #2Taking out (Extraction)

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 secure and aesthetically pleasing fixation of non-circular, cabochon-shaped stones on timepiece control members, ensuring the stone's visibility and maintaining the control member's profile without visible crimping, suitable for both faceted and non-faceted designs.

Implementation Method 1

The upper part of two blades attached to this front face are deformed within two notches respectively formed on two end faces of the stone so as to set the stone on the front face

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3245564B1Member for controlling a timepiece and method for manufacturing same
Publication Date: 2020.03.11 CARTIER INTERNATIONAL AG
  • EP3245564B1 patent drawingFigure 1~3
  • EP3245564B1 patent drawingFigure 4~8

AI summary

The invention relates to a member for controlling a timepiece, including a head (1) and a stem (2) capable of passing through a case of the timepiece and of engaging with a mechanism of a movement of the timepiece. The head (1) of the control member has a planar front surface (7) including two blades (8) emerging from said planar front surface (7) each extending substantially parallel to the stem (2). A precious (9) or semi-precious stone, in the shape of a cabochon, cut so as to have a planar base (10) and two parallel end surfaces (11, 12) each provided with a notch (11', 12'), rests via the planar base (10) thereof on the planar front surface (7) of the head (1). Said stone (9) is held in place by the upper portions of the blades (8) which are pushed into said notches (11', 12') of the end surfaces (11, 12) of the stone (9). The invention also relates to a method for manufacturing such a control member.